diff --git a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/PushAggregateIntoNestedSubplanRule.java b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/PushAggregateIntoNestedSubplanRule.java
index 1b1bc93..2b98762 100644
--- a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/PushAggregateIntoNestedSubplanRule.java
+++ b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/PushAggregateIntoNestedSubplanRule.java
@@ -111,9 +111,7 @@
             }
         }
         // Removes subplans.
-        for (Map.Entry<AbstractOperatorWithNestedPlans, List<ILogicalPlan>> entry : nspToSubplanListMap.entrySet()) {
-            entry.getKey().getNestedPlans().removeAll(entry.getValue());
-        }
+        nspToSubplanListMap.forEach((key, value) -> key.getNestedPlans().removeAll(value));
     }
 
     private boolean collectVarsBottomUp(Mutable<ILogicalOperator> opRef, IOptimizationContext context,
diff --git a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/am/InvertedIndexAccessMethod.java b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/am/InvertedIndexAccessMethod.java
index 19c6da7..8e09164 100644
--- a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/am/InvertedIndexAccessMethod.java
+++ b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/am/InvertedIndexAccessMethod.java
@@ -653,11 +653,11 @@
         // Replace the variables in the join condition based on the mapping of variables
         // in the new probe subtree.
         Map<LogicalVariable, LogicalVariable> varMapping = firstDeepCopyVisitor.getInputToOutputVariableMapping();
-        for (Map.Entry<LogicalVariable, LogicalVariable> varMapEntry : varMapping.entrySet()) {
-            if (varMapEntry.getKey() != varMapEntry.getValue()) {
-                joinCond.substituteVar(varMapEntry.getKey(), varMapEntry.getValue());
+        varMapping.forEach((key, value) -> {
+            if (key != value) {
+                joinCond.substituteVar(key, value);
             }
-        }
+        });
         return originalProbeSubTreeRootRef;
     }
 
@@ -726,9 +726,7 @@
         // condition since we deep-copied one of the scanner subtrees which
         // changed variables.
         AbstractBinaryJoinOperator joinOp = (AbstractBinaryJoinOperator) joinRef.getValue();
-        for (Map.Entry<LogicalVariable, LogicalVariable> entry : copyVarMap.entrySet()) {
-            joinOp.getCondition().getValue().substituteVar(entry.getKey(), entry.getValue());
-        }
+        copyVarMap.forEach((key, value) -> joinOp.getCondition().getValue().substituteVar(key, value));
         joinOp.getInputs().clear();
         joinOp.getInputs().add(new MutableObject<ILogicalOperator>(scanSubTree));
         // Make sure that the build input (which may be materialized causing blocking) comes from
diff --git a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/subplan/InlineAllNtsInSubplanVisitor.java b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/subplan/InlineAllNtsInSubplanVisitor.java
index 961dcc1..9a49472 100644
--- a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/subplan/InlineAllNtsInSubplanVisitor.java
+++ b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/subplan/InlineAllNtsInSubplanVisitor.java
@@ -53,10 +53,10 @@
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AggregateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AssignOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.DataSourceScanOperator;
+import org.apache.hyracks.algebricks.core.algebra.operators.logical.DelegateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.DistinctOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.EmptyTupleSourceOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.ExchangeOperator;
-import org.apache.hyracks.algebricks.core.algebra.operators.logical.DelegateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.GroupByOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.InnerJoinOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.IntersectOperator;
@@ -86,43 +86,43 @@
 import org.apache.hyracks.algebricks.core.algebra.util.OperatorManipulationUtil;
 import org.apache.hyracks.algebricks.core.algebra.visitors.IQueryOperatorVisitor;
 
-/*
-    This visitor inlines all nested tuple source operators in the query
-    plan rooted at the operator being visited, with a deep copy of the query
-    plan rooted at the input <code>subplanInputOperator</code>.
-
-    The visitor ensures that the variables used to correlate between the
-    query plan rooted at <code>subplanInputOperator</code> are propagated
-    to the operator being visited.
-
-    ----------------------------------
-    Here is an abstract example.
-    The original query plan:
-    --Op1
-      --Subplan{
-        --AggregateOp
-          --NestedOp
-            .....
-              --Nested-Tuple-Source
-        }
-        --InputOp
-          .....
-
-    After we call NestedOp.accept(....) with this visitor. We will get an
-    intermediate plan that looks like:
-    --Op1
-      --Subplan{
-        --AggregateOp
-          --NestedOp
-            .....
-              --InputOp'
-                ....
-        }
-        --InputOp
-          .....
-     The plan rooted at InputOp' is a deep copy of the plan rooted at InputOp
-     with a different set of variables.
-
+/**
+ *   This visitor inlines all nested tuple source operators in the query
+ *   plan rooted at the operator being visited, with a deep copy of the query
+ *   plan rooted at the input <code>subplanInputOperator</code>.
+ *
+ *   The visitor ensures that the variables used to correlate between the
+ *   query plan rooted at <code>subplanInputOperator</code> are propagated
+ *   to the operator being visited.
+ *
+ *   ----------------------------------
+ *   Here is an abstract example.
+ *   The original query plan:
+ *   --Op1
+ *     --Subplan{
+ *       --AggregateOp
+ *         --NestedOp
+ *           .....
+ *             --Nested-Tuple-Source
+ *       }
+ *       --InputOp
+ *         .....
+ *
+ *   After we call NestedOp.accept(....) with this visitor. We will get an
+ *   intermediate plan that looks like:
+ *   --Op1
+ *     --Subplan{
+ *       --AggregateOp
+ *         --NestedOp
+ *           .....
+ *             --InputOp'
+ *               ....
+ *       }
+ *       --InputOp
+ *         .....
+ *    The plan rooted at InputOp' is a deep copy of the plan rooted at InputOp
+ *    with a different set of variables.
+ *
  */
 class InlineAllNtsInSubplanVisitor implements IQueryOperatorVisitor<ILogicalOperator, Void> {
     // The optimization context.
@@ -218,8 +218,8 @@
         for (LogicalVariable keyVar : correlatedKeyVars) {
             if (!groupKeyVars.contains(keyVar)) {
                 LogicalVariable newVar = context.newVar();
-                op.getGroupByList().add(new Pair<LogicalVariable, Mutable<ILogicalExpression>>(newVar,
-                        new MutableObject<ILogicalExpression>(new VariableReferenceExpression(keyVar))));
+                op.getGroupByList()
+                        .add(new Pair<>(newVar, new MutableObject<>(new VariableReferenceExpression(keyVar))));
                 addedGroupKeyMapping.put(keyVar, newVar);
             }
         }
@@ -237,9 +237,7 @@
         }
 
         // Updates the var mapping for added group-by keys.
-        for (Map.Entry<LogicalVariable, LogicalVariable> entry : addedGroupKeyMapping.entrySet()) {
-            updateInputToOutputVarMapping(entry.getKey(), entry.getValue(), false);
-        }
+        addedGroupKeyMapping.forEach((key, value) -> updateInputToOutputVarMapping(key, value, false));
         return op;
     }
 
@@ -260,23 +258,23 @@
         ILogicalOperator assignOp = assignOpAndRecordVar.first;
         LogicalVariable recordVar = assignOpAndRecordVar.second;
         ILogicalOperator inputOp = op.getInputs().get(0).getValue();
-        assignOp.getInputs().add(new MutableObject<ILogicalOperator>(inputOp));
+        assignOp.getInputs().add(new MutableObject<>(inputOp));
 
         // Rewrites limit to a group-by with limit as its nested operator.
         Pair<ILogicalOperator, LogicalVariable> gbyOpAndAggVar = wrapLimitInGroupBy(op, recordVar, inputLiveVars);
         ILogicalOperator gbyOp = gbyOpAndAggVar.first;
         LogicalVariable aggVar = gbyOpAndAggVar.second;
-        gbyOp.getInputs().add(new MutableObject<ILogicalOperator>(assignOp));
+        gbyOp.getInputs().add(new MutableObject<>(assignOp));
 
         // Adds an unnest operators on top of the group-by operator.
         Pair<ILogicalOperator, LogicalVariable> unnestOpAndUnnestVar = createUnnestForAggregatedList(aggVar);
         ILogicalOperator unnestOp = unnestOpAndUnnestVar.first;
         LogicalVariable unnestVar = unnestOpAndUnnestVar.second;
-        unnestOp.getInputs().add(new MutableObject<ILogicalOperator>(gbyOp));
+        unnestOp.getInputs().add(new MutableObject<>(gbyOp));
 
         // Adds field accesses to recover input live variables.
         ILogicalOperator fieldAccessAssignOp = createFieldAccessAssignOperator(unnestVar, inputLiveVars);
-        fieldAccessAssignOp.getInputs().add(new MutableObject<ILogicalOperator>(unnestOp));
+        fieldAccessAssignOp.getInputs().add(new MutableObject<>(unnestOp));
 
         OperatorManipulationUtil.computeTypeEnvironmentBottomUp(fieldAccessAssignOp, context);
         return fieldAccessAssignOp;
@@ -288,10 +286,10 @@
         List<Mutable<ILogicalExpression>> recordConstructorArgs = new ArrayList<>();
         for (LogicalVariable inputLiveVar : inputLiveVars) {
             if (!correlatedKeyVars.contains(inputLiveVar)) {
-                recordConstructorArgs.add(new MutableObject<ILogicalExpression>(new ConstantExpression(
+                recordConstructorArgs.add(new MutableObject<>(new ConstantExpression(
                         new AsterixConstantValue(new AString(Integer.toString(inputLiveVar.getId()))))));
                 recordConstructorArgs
-                        .add(new MutableObject<ILogicalExpression>(new VariableReferenceExpression(inputLiveVar)));
+                        .add(new MutableObject<>(new VariableReferenceExpression(inputLiveVar)));
             }
         }
         LogicalVariable recordVar = context.newVar();
@@ -300,7 +298,7 @@
                         FunctionUtil.getFunctionInfo(BuiltinFunctions.OPEN_RECORD_CONSTRUCTOR),
                         recordConstructorArgs));
         AssignOperator assignOp = new AssignOperator(recordVar, recordExprRef);
-        return new Pair<ILogicalOperator, LogicalVariable>(assignOp, recordVar);
+        return new Pair<>(assignOp, recordVar);
     }
 
     private Pair<ILogicalOperator, LogicalVariable> wrapLimitInGroupBy(ILogicalOperator op, LogicalVariable recordVar,
@@ -345,7 +343,7 @@
 
         // Adds a nested tuple source operator as the input operator to the
         // limit operator.
-        NestedTupleSourceOperator nts = new NestedTupleSourceOperator(new MutableObject<ILogicalOperator>(gbyOp));
+        NestedTupleSourceOperator nts = new NestedTupleSourceOperator(new MutableObject<>(gbyOp));
         currentOp.getInputs().add(new MutableObject<>(nts));
 
         // Sets the root of the added nested plan to the aggregate operator.
@@ -365,15 +363,15 @@
     private Pair<ILogicalOperator, LogicalVariable> createUnnestForAggregatedList(LogicalVariable aggVar) {
         LogicalVariable unnestVar = context.newVar();
         // Creates an unnest function expression.
-        Mutable<ILogicalExpression> unnestArg = new MutableObject<ILogicalExpression>(
+        Mutable<ILogicalExpression> unnestArg = new MutableObject<>(
                 new VariableReferenceExpression(aggVar));
-        List<Mutable<ILogicalExpression>> unnestArgList = new ArrayList<Mutable<ILogicalExpression>>();
+        List<Mutable<ILogicalExpression>> unnestArgList = new ArrayList<>();
         unnestArgList.add(unnestArg);
-        Mutable<ILogicalExpression> unnestExpr = new MutableObject<ILogicalExpression>(
+        Mutable<ILogicalExpression> unnestExpr = new MutableObject<>(
                 new UnnestingFunctionCallExpression(
                         FunctionUtil.getFunctionInfo(BuiltinFunctions.SCAN_COLLECTION), unnestArgList));
         ILogicalOperator unnestOp = new UnnestOperator(unnestVar, unnestExpr);
-        return new Pair<ILogicalOperator, LogicalVariable>(unnestOp, unnestVar);
+        return new Pair<>(unnestOp, unnestVar);
     }
 
     private ILogicalOperator createFieldAccessAssignOperator(LogicalVariable recordVar,
@@ -388,17 +386,16 @@
                 fieldAccessVars.add(newVar);
                 // fieldAcess expr
                 List<Mutable<ILogicalExpression>> argRefs = new ArrayList<>();
-                argRefs.add(new MutableObject<ILogicalExpression>(new VariableReferenceExpression(recordVar)));
-                argRefs.add(new MutableObject<ILogicalExpression>(new ConstantExpression(
+                argRefs.add(new MutableObject<>(new VariableReferenceExpression(recordVar)));
+                argRefs.add(new MutableObject<>(new ConstantExpression(
                         new AsterixConstantValue(new AString(Integer.toString(inputLiveVar.getId()))))));
-                fieldAccessExprs.add(new MutableObject<ILogicalExpression>(new ScalarFunctionCallExpression(
+                fieldAccessExprs.add(new MutableObject<>(new ScalarFunctionCallExpression(
                         FunctionUtil.getFunctionInfo(BuiltinFunctions.FIELD_ACCESS_BY_NAME), argRefs)));
                 // Updates variable mapping for ancestor operators.
                 updateInputToOutputVarMapping(inputLiveVar, newVar, false);
             }
         }
-        AssignOperator fieldAccessAssignOp = new AssignOperator(fieldAccessVars, fieldAccessExprs);
-        return fieldAccessAssignOp;
+        return new AssignOperator(fieldAccessVars, fieldAccessExprs);
     }
 
     @Override
@@ -429,15 +426,13 @@
         correlatedKeyVars.clear();
         correlatedKeyVars.addAll(primaryOpAndVars.second);
         // Update key variables and input-output-var mapping.
-        for (Map.Entry<LogicalVariable, LogicalVariable> entry : varMap.entrySet()) {
-            LogicalVariable oldVar = entry.getKey();
-            LogicalVariable newVar = entry.getValue();
+        varMap.forEach((oldVar, newVar) -> {
             if (correlatedKeyVars.contains(oldVar)) {
                 correlatedKeyVars.remove(oldVar);
                 correlatedKeyVars.add(newVar);
             }
             updateInputToOutputVarMapping(oldVar, newVar, true);
-        }
+        });
         return primaryOpAndVars.first;
     }
 
@@ -454,8 +449,8 @@
         List<Pair<IOrder, Mutable<ILogicalExpression>>> orderExprList = new ArrayList<>();
         // Adds keyVars to the prefix of sorting columns.
         for (LogicalVariable keyVar : correlatedKeyVars) {
-            orderExprList.add(new Pair<IOrder, Mutable<ILogicalExpression>>(OrderOperator.ASC_ORDER,
-                    new MutableObject<ILogicalExpression>(new VariableReferenceExpression(keyVar))));
+            orderExprList.add(
+                    new Pair<>(OrderOperator.ASC_ORDER, new MutableObject<>(new VariableReferenceExpression(keyVar))));
         }
         orderExprList.addAll(op.getOrderExpressions());
 
@@ -636,7 +631,7 @@
             return op;
         }
         GroupByOperator gbyOp = new GroupByOperator();
-        // Creates a copy of correlatedKeyVars, to fix the ConcurrentModificationExcetpion in ASTERIXDB-1581.
+        // Creates a copy of correlatedKeyVars, to fix the ConcurrentModificationException in ASTERIXDB-1581.
         List<LogicalVariable> copyOfCorrelatedKeyVars = new ArrayList<>(correlatedKeyVars);
         for (LogicalVariable keyVar : copyOfCorrelatedKeyVars) {
             // This limits the visitor can only be applied to a nested logical
@@ -652,7 +647,7 @@
         ILogicalOperator inputOp = op.getInputs().get(0).getValue();
         gbyOp.getInputs().add(new MutableObject<>(inputOp));
 
-        NestedTupleSourceOperator nts = new NestedTupleSourceOperator(new MutableObject<ILogicalOperator>(gbyOp));
+        NestedTupleSourceOperator nts = new NestedTupleSourceOperator(new MutableObject<>(gbyOp));
         op.getInputs().clear();
         op.getInputs().add(new MutableObject<>(nts));
 
@@ -718,7 +713,7 @@
             subplanInputVarToCurrentVarMap.put(oldVar, newVar);
             currentVarToSubplanInputVarMap.put(newVar, oldVar);
         } else {
-            varMapIntroducedByRewriting.add(new Pair<LogicalVariable, LogicalVariable>(oldVar, newVar));
+            varMapIntroducedByRewriting.add(new Pair<>(oldVar, newVar));
         }
     }
 
@@ -726,8 +721,8 @@
             List<Pair<IOrder, Mutable<ILogicalExpression>>> orderExprs) {
         List<Pair<IOrder, Mutable<ILogicalExpression>>> clonedOrderExprs = new ArrayList<>();
         for (Pair<IOrder, Mutable<ILogicalExpression>> orderExpr : orderExprs) {
-            clonedOrderExprs.add(new Pair<IOrder, Mutable<ILogicalExpression>>(orderExpr.first,
-                    new MutableObject<ILogicalExpression>(orderExpr.second.getValue().cloneExpression())));
+            clonedOrderExprs.add(
+                    new Pair<>(orderExpr.first, new MutableObject<>(orderExpr.second.getValue().cloneExpression())));
         }
         return clonedOrderExprs;
     }
diff --git a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/subplan/InlineSubplanInputForNestedTupleSourceRule.java b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/subplan/InlineSubplanInputForNestedTupleSourceRule.java
index 0bda955..8ab8b1d 100644
--- a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/subplan/InlineSubplanInputForNestedTupleSourceRule.java
+++ b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/optimizer/rules/subplan/InlineSubplanInputForNestedTupleSourceRule.java
@@ -48,9 +48,9 @@
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.LeftOuterJoinOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.NestedTupleSourceOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.OrderOperator;
+import org.apache.hyracks.algebricks.core.algebra.operators.logical.OrderOperator.IOrder;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.SelectOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.SubplanOperator;
-import org.apache.hyracks.algebricks.core.algebra.operators.logical.OrderOperator.IOrder;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities;
 import org.apache.hyracks.algebricks.core.algebra.plan.ALogicalPlanImpl;
 import org.apache.hyracks.algebricks.core.algebra.util.OperatorManipulationUtil;
@@ -324,9 +324,7 @@
                     childrenRef,
                     context);
             changed = changed || resultFromChild.first;
-            for (Map.Entry<LogicalVariable, LogicalVariable> entry : resultFromChild.second.entrySet()) {
-                LogicalVariable oldVar = entry.getKey();
-                LogicalVariable newVar = entry.getValue();
+            resultFromChild.second.forEach((oldVar, newVar) -> {
                 if (liveVars.contains(oldVar)) {
                     // Maps live variables for its ancestors.
                     replacedVarMapForAncestor.put(oldVar, newVar);
@@ -337,7 +335,7 @@
                         oldVar = newVar;
                     }
                 }
-            }
+            });
             replacedVarMap.putAll(resultFromChild.second);
         }
         VariableUtilities.substituteVariables(op, replacedVarMap, context);
diff --git a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/translator/AbstractLangTranslator.java b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/translator/AbstractLangTranslator.java
index c3f01e8..db6f985 100644
--- a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/translator/AbstractLangTranslator.java
+++ b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/translator/AbstractLangTranslator.java
@@ -154,13 +154,14 @@
                 DatasetDecl datasetStmt = (DatasetDecl) stmt;
                 Map<String, String> hints = datasetStmt.getHints();
                 if (hints != null && !hints.isEmpty()) {
-                    Pair<Boolean, String> validationResult = null;
-                    StringBuffer errorMsgBuffer = new StringBuffer();
+                    StringBuilder errorMsgBuffer = new StringBuilder();
                     for (Entry<String, String> hint : hints.entrySet()) {
-                        validationResult = DatasetHints.validate(appCtx, hint.getKey(), hint.getValue());
+                        Pair<Boolean, String> validationResult = DatasetHints.validate(appCtx, hint.getKey(),
+                                hint.getValue());
                         if (!validationResult.first) {
-                            errorMsgBuffer.append("Dataset: " + datasetStmt.getName().getValue()
-                                    + " error in processing hint: " + hint.getKey() + " " + validationResult.second);
+                            errorMsgBuffer.append("Dataset: ").append(datasetStmt.getName().getValue())
+                                    .append(" error in processing hint: ").append(hint.getKey()).append(" ")
+                                    .append(validationResult.second);
                             errorMsgBuffer.append(" \n");
                         }
                     }
diff --git a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/translator/LangExpressionToPlanTranslator.java b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/translator/LangExpressionToPlanTranslator.java
index 66a1073..d5f41df 100644
--- a/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/translator/LangExpressionToPlanTranslator.java
+++ b/asterixdb/asterix-algebra/src/main/java/org/apache/asterix/translator/LangExpressionToPlanTranslator.java
@@ -25,7 +25,6 @@
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
-import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicLong;
@@ -39,7 +38,6 @@
 import org.apache.asterix.common.exceptions.MetadataException;
 import org.apache.asterix.common.functions.FunctionConstants;
 import org.apache.asterix.common.functions.FunctionSignature;
-import org.apache.asterix.external.util.ExternalDataUtils;
 import org.apache.asterix.lang.aql.util.RangeMapBuilder;
 import org.apache.asterix.lang.common.base.Expression;
 import org.apache.asterix.lang.common.base.Expression.Kind;
@@ -82,7 +80,6 @@
 import org.apache.asterix.metadata.declared.ResultSetDataSink;
 import org.apache.asterix.metadata.declared.ResultSetSinkId;
 import org.apache.asterix.metadata.entities.Dataset;
-import org.apache.asterix.metadata.entities.Feed;
 import org.apache.asterix.metadata.entities.Function;
 import org.apache.asterix.metadata.entities.InternalDatasetDetails;
 import org.apache.asterix.metadata.functions.ExternalFunctionCompilerUtil;
@@ -96,7 +93,6 @@
 import org.apache.asterix.om.types.IAType;
 import org.apache.asterix.translator.CompiledStatements.CompiledInsertStatement;
 import org.apache.asterix.translator.CompiledStatements.CompiledLoadFromFileStatement;
-import org.apache.asterix.translator.CompiledStatements.CompiledSubscribeFeedStatement;
 import org.apache.asterix.translator.CompiledStatements.CompiledUpsertStatement;
 import org.apache.asterix.translator.CompiledStatements.ICompiledDmlStatement;
 import org.apache.asterix.translator.util.PlanTranslationUtil;
@@ -1487,12 +1483,12 @@
 
                 // Updates mapping like <$a, $b> in varMap to <$a, $c>, where there is a mapping <$b, $c>
                 // in childVarMap.
-                for (Map.Entry<LogicalVariable, LogicalVariable> entry : varMap.entrySet()) {
+                varMap.entrySet().forEach(entry -> {
                     LogicalVariable newVar = childVarMap.get(entry.getValue());
                     if (newVar != null) {
                         entry.setValue(newVar);
                     }
-                }
+                });
                 varMap.putAll(childVarMap);
                 ++childIndex;
             }
diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/common/APIFramework.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/common/APIFramework.java
index 4b78b93..567d587 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/common/APIFramework.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/common/APIFramework.java
@@ -427,9 +427,7 @@
         int perNodeParallelismMax = parallelism / numNodes + 1;
         List<String> allNodes = new ArrayList<>();
         Set<String> selectedNodesWithOneMorePartition = new HashSet<>();
-        for (Map.Entry<String, NodeControllerInfo> entry : ncMap.entrySet()) {
-            allNodes.add(entry.getKey());
-        }
+        ncMap.forEach((key, value) -> allNodes.add(key));
         Random random = new Random();
         for (int index = numNodesWithOneMorePartition; index >= 1; --index) {
             int pick = random.nextInt(index);
@@ -439,9 +437,8 @@
 
         // Generates cluster locations, which has duplicates for a node if it contains more than one partitions.
         List<String> locations = new ArrayList<>();
-        for (Map.Entry<String, NodeControllerInfo> entry : ncMap.entrySet()) {
-            String nodeId = entry.getKey();
-            int availableCores = entry.getValue().getNumAvailableCores();
+        ncMap.forEach((nodeId, value) -> {
+            int availableCores = value.getNumAvailableCores();
             int nodeParallelism =
                     selectedNodesWithOneMorePartition.contains(nodeId) ? perNodeParallelismMax : perNodeParallelismMin;
             int coresToUse =
@@ -449,17 +446,13 @@
             for (int count = 0; count < coresToUse; ++count) {
                 locations.add(nodeId);
             }
-        }
+        });
         return new AlgebricksAbsolutePartitionConstraint(locations.toArray(new String[0]));
     }
 
     // Gets the total number of available cores in the cluster.
     private static int getTotalNumCores(Map<String, NodeControllerInfo> ncMap) {
-        int sum = 0;
-        for (Map.Entry<String, NodeControllerInfo> entry : ncMap.entrySet()) {
-            sum += entry.getValue().getNumAvailableCores();
-        }
-        return sum;
+        return ncMap.values().stream().mapToInt(NodeControllerInfo::getNumAvailableCores).sum();
     }
 
     // Gets the frame limit.
diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/VersionApiServlet.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/VersionApiServlet.java
index 81e0cfd..8d028a5 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/VersionApiServlet.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/VersionApiServlet.java
@@ -50,9 +50,7 @@
         ICcApplicationContext props = (ICcApplicationContext) ctx.get(ASTERIX_APP_CONTEXT_INFO_ATTR);
         Map<String, String> buildProperties = props.getBuildProperties().getAllProps();
         ObjectNode responseObject = OBJECT_MAPPER.createObjectNode();
-        for (Map.Entry<String, String> e : buildProperties.entrySet()) {
-            responseObject.put(e.getKey(), e.getValue());
-        }
+        buildProperties.forEach(responseObject::put);
         try {
             HttpUtil.setContentType(response, HttpUtil.ContentType.TEXT_PLAIN, HttpUtil.Encoding.UTF8);
         } catch (IOException e) {
diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/nc/RecoveryManager.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/nc/RecoveryManager.java
index 04e6313..a502de9 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/nc/RecoveryManager.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/nc/RecoveryManager.java
@@ -499,7 +499,7 @@
         int abortedJobId = txnContext.getJobId().getId();
         // Obtain the first/last log record LSNs written by the Job
         long firstLSN = txnContext.getFirstLSN();
-        /**
+        /*
          * The effect of any log record with LSN below minFirstLSN has already been written to disk and
          * will not be rolled back. Therefore, we will set the first LSN of the job to the maximum of
          * minFirstLSN and the job's first LSN.
diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/replication/AutoFaultToleranceStrategy.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/replication/AutoFaultToleranceStrategy.java
index 80fdbd6..4ac1305 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/replication/AutoFaultToleranceStrategy.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/replication/AutoFaultToleranceStrategy.java
@@ -25,7 +25,6 @@
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Set;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -67,7 +66,6 @@
 import org.apache.asterix.util.FaultToleranceUtil;
 import org.apache.hyracks.api.application.ICCServiceContext;
 import org.apache.hyracks.api.application.IClusterLifecycleListener.ClusterEventType;
-import org.apache.hyracks.api.config.IOption;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
 
 public class AutoFaultToleranceStrategy implements IFaultToleranceStrategy {
@@ -163,9 +161,8 @@
                 LOGGER.info("Partitions to recover: " + lostPartitions);
             }
             //For each replica, send a request to takeover the assigned partitions
-            for (Entry<String, List<Integer>> entry : partitionRecoveryPlan.entrySet()) {
-                String replica = entry.getKey();
-                Integer[] partitionsToTakeover = entry.getValue().toArray(new Integer[entry.getValue().size()]);
+            partitionRecoveryPlan.forEach((replica, value) -> {
+                Integer[] partitionsToTakeover = value.toArray(new Integer[value.size()]);
                 long requestId = clusterRequestId++;
                 TakeoverPartitionsRequestMessage takeoverRequest = new TakeoverPartitionsRequestMessage(requestId,
                         replica, partitionsToTakeover);
@@ -180,7 +177,7 @@
                      */
                     LOGGER.log(Level.WARNING, "Failed to send takeover request: " + takeoverRequest, e);
                 }
-            }
+            });
         }
     }
 
diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/replication/NodeFailbackPlan.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/replication/NodeFailbackPlan.java
index bc069b9..ab938d2 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/replication/NodeFailbackPlan.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/replication/NodeFailbackPlan.java
@@ -163,11 +163,11 @@
          */
         for (String participant : participants) {
             Set<Integer> partitionToPrepareForFailback = new HashSet<>();
-            for (Map.Entry<Integer, String> entry : partition2nodeMap.entrySet()) {
-                if (entry.getValue().equals(participant)) {
-                    partitionToPrepareForFailback.add(entry.getKey());
+            partition2nodeMap.forEach((key, value) -> {
+                if (value.equals(participant)) {
+                    partitionToPrepareForFailback.add(key);
                 }
-            }
+            });
             PreparePartitionsFailbackRequestMessage msg = new PreparePartitionsFailbackRequestMessage(planId,
                     requestId++, participant, partitionToPrepareForFailback);
             if (participant.equals(nodeToReleaseMetadataManager)) {
diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/translator/QueryTranslator.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/translator/QueryTranslator.java
index d3be23c..e45df8b 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/translator/QueryTranslator.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/translator/QueryTranslator.java
@@ -36,7 +36,6 @@
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Properties;
 import java.util.Set;
 import java.util.concurrent.ExecutorService;
@@ -1981,9 +1980,7 @@
                     throw new AlgebricksException("Unable to read policy file" + cfps.getSourcePolicyFile(), e);
                 }
                 Map<String, String> policyProperties = new HashMap<>();
-                for (Entry<Object, Object> entry : prop.entrySet()) {
-                    policyProperties.put((String) entry.getKey(), (String) entry.getValue());
-                }
+                prop.forEach((key, value) -> policyProperties.put((String) key, (String) value));
                 newPolicy = new FeedPolicyEntity(dataverse, policy, description, policyProperties);
             }
             MetadataManager.INSTANCE.addFeedPolicy(mdTxnCtx, newPolicy);
diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/utils/FeedOperations.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/utils/FeedOperations.java
index 2b9386e..9cce91b 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/utils/FeedOperations.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/utils/FeedOperations.java
@@ -330,8 +330,7 @@
 
             // copy connectors
             connectorIdMapping.clear();
-            for (Entry<ConnectorDescriptorId, IConnectorDescriptor> entry : subJob.getConnectorMap().entrySet()) {
-                IConnectorDescriptor connDesc = entry.getValue();
+            subJob.getConnectorMap().forEach((key, connDesc) -> {
                 ConnectorDescriptorId newConnId;
                 if (connDesc instanceof MToNPartitioningConnectorDescriptor) {
                     MToNPartitioningConnectorDescriptor m2nConn = (MToNPartitioningConnectorDescriptor) connDesc;
@@ -341,8 +340,8 @@
                 } else {
                     newConnId = jobSpec.createConnectorDescriptor(connDesc);
                 }
-                connectorIdMapping.put(entry.getKey(), newConnId);
-            }
+                connectorIdMapping.put(key, newConnId);
+            });
 
             // make connections between operators
             for (Entry<ConnectorDescriptorId, Pair<Pair<IOperatorDescriptor, Integer>,
@@ -406,12 +405,12 @@
             }
 
             // set count constraints
-            for (Entry<OperatorDescriptorId, Integer> entry : operatorCounts.entrySet()) {
-                IOperatorDescriptor opDesc = jobSpec.getOperatorMap().get(entry.getKey());
-                if (!operatorLocations.keySet().contains(entry.getKey())) {
-                    PartitionConstraintHelper.addPartitionCountConstraint(jobSpec, opDesc, entry.getValue());
+            operatorCounts.forEach((key, value) -> {
+                IOperatorDescriptor opDesc = jobSpec.getOperatorMap().get(key);
+                if (!operatorLocations.keySet().contains(key)) {
+                    PartitionConstraintHelper.addPartitionCountConstraint(jobSpec, opDesc, value);
                 }
-            }
+            });
             // roots
             for (OperatorDescriptorId root : subJob.getRoots()) {
                 jobSpec.addRoot(jobSpec.getOperatorMap().get(operatorIdMapping.get(root)));
diff --git a/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/context/DatasetLifecycleManager.java b/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/context/DatasetLifecycleManager.java
index 559d57c..cdb7bb3 100644
--- a/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/context/DatasetLifecycleManager.java
+++ b/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/context/DatasetLifecycleManager.java
@@ -491,11 +491,8 @@
         sb.append(String.format(idxHeaderFormat, "DatasetID", "ResourceID", "Open", "Reference Count", "Index"));
         for (DatasetResource dsr : datasets.values()) {
             DatasetInfo dsInfo = dsr.getDatasetInfo();
-            for (Map.Entry<Long, IndexInfo> entry : dsInfo.getIndexes().entrySet()) {
-                IndexInfo iInfo = entry.getValue();
-                sb.append(String.format(idxFormat, dsInfo.getDatasetID(), entry.getKey(), iInfo.isOpen(),
-                        iInfo.getReferenceCount(), iInfo.getIndex()));
-            }
+            dsInfo.getIndexes().forEach((key, iInfo) -> sb.append(String.format(idxFormat, dsInfo.getDatasetID(), key,
+                    iInfo.isOpen(), iInfo.getReferenceCount(), iInfo.getIndex())));
         }
         outputStream.write(sb.toString().getBytes());
     }
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/indexing/IndexingScheduler.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/indexing/IndexingScheduler.java
index 870a6df..5212892 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/indexing/IndexingScheduler.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/indexing/IndexingScheduler.java
@@ -23,6 +23,7 @@
 import java.net.UnknownHostException;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
 import java.util.List;
@@ -80,14 +81,14 @@
      */
     public String[] getLocationConstraints(InputSplit[] splits) throws HyracksException {
         if (splits == null) {
-            /** deal the case when the splits array is null */
+            /* deal the case when the splits array is null */
             return new String[] {};
         }
         int[] workloads = new int[NCs.length];
         Arrays.fill(workloads, 0);
         String[] locations = new String[splits.length];
         Map<String, IntWritable> locationToNumOfSplits = new HashMap<String, IntWritable>();
-        /**
+        /*
          * upper bound is number of splits
          */
         int upperBoundSlots = splits.length;
@@ -96,7 +97,7 @@
             Random random = new Random(System.currentTimeMillis());
             boolean scheduled[] = new boolean[splits.length];
             Arrays.fill(scheduled, false);
-            /**
+            /*
              * scan the splits and build the popularity map
              * give the machines with less local splits more scheduling priority
              */
@@ -105,7 +106,7 @@
             for (String location : locationToNumOfSplits.keySet()) {
                 locationToNumOfAssignement.put(location, 0);
             }
-            /**
+            /*
              * push data-local upper-bounds slots to each machine
              */
             scheduleLocalSlots(splits, workloads, locations, upperBoundSlots, random, scheduled, locationToNumOfSplits,
@@ -119,7 +120,7 @@
             }
             LOGGER.info("Data local rate: "
                     + (scheduled.length == 0 ? 0.0 : ((float) dataLocalCount / (float) (scheduled.length))));
-            /**
+            /*
              * push non-data-local upper-bounds slots to each machine
              */
             locationToNumOfAssignement.clear();
@@ -158,22 +159,15 @@
             boolean[] scheduled, final HashMap<String, Integer> locationToNumOfAssignement)
                     throws IOException, UnknownHostException {
 
-        PriorityQueue<String> scheduleCadndiates = new PriorityQueue<String>(NCs.length, new Comparator<String>() {
-            @Override
-            public int compare(String s1, String s2) {
-                return locationToNumOfAssignement.get(s1).compareTo(locationToNumOfAssignement.get(s2));
-            }
+        PriorityQueue<String> scheduleCadndiates = new PriorityQueue<String>(NCs.length,
+                Comparator.comparing(locationToNumOfAssignement::get));
 
-        });
-
-        for (String nc : NCs) {
-            scheduleCadndiates.add(nc);
-        }
-        /**
+        scheduleCadndiates.addAll(Arrays.asList(NCs));
+        /*
          * schedule no-local file reads
          */
         for (int i = 0; i < splits.length; i++) {
-            /** if there is no data-local NC choice, choose a random one */
+            /* if there is no data-local NC choice, choose a random one */
             if (!scheduled[i]) {
                 String selectedNcName = scheduleCadndiates.remove();
                 if (selectedNcName != null) {
@@ -209,55 +203,48 @@
     private void scheduleLocalSlots(InputSplit[] splits, int[] workloads, String[] locations, int slots, Random random,
             boolean[] scheduled, final Map<String, IntWritable> locationToNumSplits,
             final HashMap<String, Integer> locationToNumOfAssignement) throws IOException, UnknownHostException {
-        /** scheduling candidates will be ordered inversely according to their popularity */
-        PriorityQueue<String> scheduleCadndiates = new PriorityQueue<String>(3, new Comparator<String>() {
-            @Override
-            public int compare(String s1, String s2) {
-                int assignmentDifference = locationToNumOfAssignement.get(s1)
-                        .compareTo(locationToNumOfAssignement.get(s2));
-                if (assignmentDifference != 0) {
-                    return assignmentDifference;
-                }
-                return locationToNumSplits.get(s1).compareTo(locationToNumSplits.get(s2));
+        /* scheduling candidates will be ordered inversely according to their popularity */
+        PriorityQueue<String> scheduleCadndiates = new PriorityQueue<>(3, (s1, s2) -> {
+            int assignmentDifference = locationToNumOfAssignement.get(s1).compareTo(locationToNumOfAssignement.get(s2));
+            if (assignmentDifference != 0) {
+                return assignmentDifference;
             }
-
+            return locationToNumSplits.get(s1).compareTo(locationToNumSplits.get(s2));
         });
 
         for (int i = 0; i < splits.length; i++) {
             if (scheduled[i]) {
                 continue;
             }
-            /**
+            /*
              * get the location of all the splits
              */
             String[] locs = splits[i].getLocations();
             if (locs.length > 0) {
                 scheduleCadndiates.clear();
-                for (int j = 0; j < locs.length; j++) {
-                    scheduleCadndiates.add(locs[j]);
-                }
+                Collections.addAll(scheduleCadndiates, locs);
 
                 for (String candidate : scheduleCadndiates) {
-                    /**
+                    /*
                      * get all the IP addresses from the name
                      */
                     InetAddress[] allIps = InetAddress.getAllByName(candidate);
-                    /**
+                    /*
                      * iterate overa all ips
                      */
                     for (InetAddress ip : allIps) {
-                        /**
+                        /*
                          * if the node controller exists
                          */
                         if (ipToNcMapping.get(ip.getHostAddress()) != null) {
-                            /**
+                            /*
                              * set the ncs
                              */
                             List<String> dataLocations = ipToNcMapping.get(ip.getHostAddress());
                             int arrayPos = random.nextInt(dataLocations.size());
                             String nc = dataLocations.get(arrayPos);
                             int pos = ncNameToIndex.get(nc);
-                            /**
+                            /*
                              * check if the node is already full
                              */
                             if (workloads[pos] < slots) {
@@ -270,11 +257,11 @@
                             }
                         }
                     }
-                    /**
+                    /*
                      * break the loop for data-locations if the schedule has
                      * already been found
                      */
-                    if (scheduled[i] == true) {
+                    if (scheduled[i]) {
                         break;
                     }
                 }
@@ -319,23 +306,19 @@
             ncNameToIndex.clear();
             int i = 0;
 
-            /**
+            /*
              * build the IP address to NC map
              */
             for (Map.Entry<String, NodeControllerInfo> entry : ncNameToNcInfos.entrySet()) {
                 String ipAddr = InetAddress.getByAddress(entry.getValue().getNetworkAddress().lookupIpAddress())
                         .getHostAddress();
-                List<String> matchedNCs = ipToNcMapping.get(ipAddr);
-                if (matchedNCs == null) {
-                    matchedNCs = new ArrayList<String>();
-                    ipToNcMapping.put(ipAddr, matchedNCs);
-                }
+                List<String> matchedNCs = ipToNcMapping.computeIfAbsent(ipAddr, k -> new ArrayList<>());
                 matchedNCs.add(entry.getKey());
                 NCs[i] = entry.getKey();
                 i++;
             }
 
-            /**
+            /*
              * set up the NC name to index mapping
              */
             for (i = 0; i < NCs.length; i++) {
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/ExternalLibraryManager.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/ExternalLibraryManager.java
index 968dbf6..19a519f 100755
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/ExternalLibraryManager.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/library/ExternalLibraryManager.java
@@ -22,7 +22,6 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 
 import org.apache.asterix.common.exceptions.ErrorCode;
 import org.apache.asterix.common.exceptions.RuntimeDataException;
@@ -49,9 +48,7 @@
     public List<Pair<String, String>> getAllLibraries() {
         ArrayList<Pair<String, String>> libs = new ArrayList<>();
         synchronized (libraryClassLoaders) {
-            for (Entry<String, ClassLoader> entry : libraryClassLoaders.entrySet()) {
-                libs.add(getDataverseAndLibararyName(entry.getKey()));;
-            }
+            libraryClassLoaders.forEach((key, value) -> libs.add(getDataverseAndLibararyName(key)));
         }
         return libs;
     }
diff --git a/asterixdb/asterix-external-data/src/test/java/org/apache/asterix/external/classad/test/ClassAdToADMTest.java b/asterixdb/asterix-external-data/src/test/java/org/apache/asterix/external/classad/test/ClassAdToADMTest.java
index 74020f3..3bbcf89 100644
--- a/asterixdb/asterix-external-data/src/test/java/org/apache/asterix/external/classad/test/ClassAdToADMTest.java
+++ b/asterixdb/asterix-external-data/src/test/java/org/apache/asterix/external/classad/test/ClassAdToADMTest.java
@@ -27,7 +27,6 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 
 import org.apache.asterix.external.api.IRawRecord;
 import org.apache.asterix.external.classad.CaseInsensitiveString;
@@ -215,8 +214,7 @@
                         parser.setLexerSource(lexerSource);
                         parser.parseNext(pAd);
                         Map<CaseInsensitiveString, ExprTree> attrs = pAd.getAttrList();
-                        for (Entry<CaseInsensitiveString, ExprTree> entry : attrs.entrySet()) {
-                            ExprTree tree = entry.getValue();
+                        attrs.forEach((key, tree) -> {
                             switch (tree.getKind()) {
                                 case ATTRREF_NODE:
                                 case CLASSAD_NODE:
@@ -231,7 +229,7 @@
                                     System.out.println("Something is wrong");
                                     break;
                             }
-                        }
+                        });
                     }
                 } finally {
                     recordReader.close();
diff --git a/asterixdb/asterix-fuzzyjoin/src/main/java/org/apache/asterix/fuzzyjoin/FuzzyJoinMemory.java b/asterixdb/asterix-fuzzyjoin/src/main/java/org/apache/asterix/fuzzyjoin/FuzzyJoinMemory.java
index 9107f63..e42ba51 100644
--- a/asterixdb/asterix-fuzzyjoin/src/main/java/org/apache/asterix/fuzzyjoin/FuzzyJoinMemory.java
+++ b/asterixdb/asterix-fuzzyjoin/src/main/java/org/apache/asterix/fuzzyjoin/FuzzyJoinMemory.java
@@ -27,7 +27,6 @@
 import java.util.Date;
 import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
 
 import org.apache.asterix.fuzzyjoin.invertedlist.InvertedListLengthList;
 import org.apache.asterix.fuzzyjoin.invertedlist.InvertedListsLengthList;
@@ -176,9 +175,9 @@
         // verify candidates
         //
         ArrayList<ResultJoin> results = new ArrayList<>();
-        for (Map.Entry<Integer, Integer> cand : counts.entrySet()) {
-            int count = cand.getValue();
-            int indexProbe = cand.getKey();
+        counts.forEach((key, value) -> {
+            int count = value;
+            int indexProbe = key;
             if (count > 0) {
                 int tokensProbe[] = records.get(indexProbe);
                 float similarity = similarityFilters.passSimilarityFilter(tokens, prefixLength, tokensProbe,
@@ -187,7 +186,7 @@
                     results.add(new ResultJoin(indexProbe, similarity));
                 }
             }
-        }
+        });
         return results;
     }
 
@@ -293,9 +292,9 @@
         // verify candidates
         //
         ArrayList<ResultSelfJoin> results = new ArrayList<>();
-        for (Map.Entry<Integer, Integer> cand : counts.entrySet()) {
-            int count = cand.getValue();
-            int indexProbe = cand.getKey();
+        counts.forEach((key, value) -> {
+            int count = value;
+            int indexProbe = key;
             if (count > 0) {
                 int tokensProbe[] = records.get(indexProbe);
                 float similarity = similarityFilters.passSimilarityFilter(tokens, prefixLength, tokensProbe,
@@ -304,7 +303,7 @@
                     results.add(new ResultSelfJoin(index, indexProbe, similarity));
                 }
             }
-        }
+        });
         return results;
     }
 }
diff --git a/asterixdb/asterix-fuzzyjoin/src/main/java/org/apache/asterix/fuzzyjoin/FuzzyJoinTokenize.java b/asterixdb/asterix-fuzzyjoin/src/main/java/org/apache/asterix/fuzzyjoin/FuzzyJoinTokenize.java
index 62b34c0..64c7e52 100644
--- a/asterixdb/asterix-fuzzyjoin/src/main/java/org/apache/asterix/fuzzyjoin/FuzzyJoinTokenize.java
+++ b/asterixdb/asterix-fuzzyjoin/src/main/java/org/apache/asterix/fuzzyjoin/FuzzyJoinTokenize.java
@@ -30,7 +30,6 @@
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
-import java.util.Map;
 
 import org.apache.asterix.fuzzyjoin.tokenizer.Tokenizer;
 import org.apache.asterix.fuzzyjoin.tokenizer.TokenizerFactory;
@@ -95,9 +94,7 @@
         input.close();
 
         ArrayList<TokenCount> tokenCounts = new ArrayList<TokenCount>();
-        for (Map.Entry<String, MutableInteger> entry : tokenCount.entrySet()) {
-            tokenCounts.add(new TokenCount(entry.getKey(), entry.getValue()));
-        }
+        tokenCount.forEach((key, value) -> tokenCounts.add(new TokenCount(key, value)));
         Collections.sort(tokenCounts);
 
         BufferedWriter outputTokens = new BufferedWriter(new FileWriter(tokensFileName));
diff --git a/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/rewrites/VariableSubstitutionEnvironment.java b/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/rewrites/VariableSubstitutionEnvironment.java
index 26f528c..a8650dd 100644
--- a/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/rewrites/VariableSubstitutionEnvironment.java
+++ b/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/rewrites/VariableSubstitutionEnvironment.java
@@ -33,9 +33,7 @@
     }
 
     public VariableSubstitutionEnvironment(Map<VariableExpr, Expression> varExprMap) {
-        for (Map.Entry<VariableExpr, Expression> entry : varExprMap.entrySet()) {
-            oldVarToNewExpressionMap.put(entry.getKey().getVar().getValue(), entry.getValue());
-        }
+        varExprMap.forEach((key, value) -> oldVarToNewExpressionMap.put(key.getVar().getValue(), value));
     }
 
     public VariableSubstitutionEnvironment(VariableSubstitutionEnvironment env) {
diff --git a/asterixdb/asterix-maven-plugins/asterix-grammar-extension-maven-plugin/src/main/java/org/apache/asterix/extension/grammar/GrammarExtensionMojo.java b/asterixdb/asterix-maven-plugins/asterix-grammar-extension-maven-plugin/src/main/java/org/apache/asterix/extension/grammar/GrammarExtensionMojo.java
index 4c750e2..17a71f2 100644
--- a/asterixdb/asterix-maven-plugins/asterix-grammar-extension-maven-plugin/src/main/java/org/apache/asterix/extension/grammar/GrammarExtensionMojo.java
+++ b/asterixdb/asterix-maven-plugins/asterix-grammar-extension-maven-plugin/src/main/java/org/apache/asterix/extension/grammar/GrammarExtensionMojo.java
@@ -216,7 +216,7 @@
             writer.newLine();
             writer.newLine();
 
-            // Extinsibles
+            // Extensibles
             for (Entry<String, Pair<String, String>> entry : extensibles.entrySet()) {
                 writer.newLine();
                 String signature = entry.getKey();
diff --git a/asterixdb/asterix-maven-plugins/lexer-generator-maven-plugin/src/main/java/org/apache/asterix/lexergenerator/LexerNode.java b/asterixdb/asterix-maven-plugins/lexer-generator-maven-plugin/src/main/java/org/apache/asterix/lexergenerator/LexerNode.java
index 4f24b1e..1820be6 100644
--- a/asterixdb/asterix-maven-plugins/lexer-generator-maven-plugin/src/main/java/org/apache/asterix/lexergenerator/LexerNode.java
+++ b/asterixdb/asterix-maven-plugins/lexer-generator-maven-plugin/src/main/java/org/apache/asterix/lexergenerator/LexerNode.java
@@ -40,12 +40,8 @@
     public LexerNode clone() {
         LexerNode node = new LexerNode();
         node.finalTokenName = this.finalTokenName;
-        for (Map.Entry<Rule, LexerNode> entry : this.actions.entrySet()) {
-            node.actions.put(entry.getKey().clone(), entry.getValue().clone());
-        }
-        for (String ongoing : this.ongoingParsing) {
-            node.ongoingParsing.add(ongoing);
-        }
+        this.actions.forEach((key, value) -> node.actions.put(key.clone(), value.clone()));
+        node.ongoingParsing.addAll(this.ongoingParsing);
         return node;
     }
 
@@ -59,9 +55,7 @@
         if (actions.size() == 0) {
             add(newRule);
         } else {
-            for (Map.Entry<Rule, LexerNode> action : actions.entrySet()) {
-                action.getValue().append(newRule);
-            }
+            actions.forEach((key, value) -> value.append(newRule));
             if (actions.containsKey(new RuleEpsilon())) {
                 actions.remove(new RuleEpsilon());
                 add(newRule);
@@ -84,9 +78,7 @@
                 throw new Exception("Rule conflict between: " + this.finalTokenName + " and " + newNode.finalTokenName);
             }
         }
-        for (String ongoing : newNode.ongoingParsing) {
-            this.ongoingParsing.add(ongoing);
-        }
+        this.ongoingParsing.addAll(newNode.ongoingParsing);
     }
 
     public void append(LexerNode node) throws Exception {
@@ -110,9 +102,7 @@
             this.finalTokenName = name;
         } else {
             ongoingParsing.add(TOKEN_PREFIX + name);
-            for (Map.Entry<Rule, LexerNode> action : actions.entrySet()) {
-                action.getValue().appendTokenName(name);
-            }
+            actions.forEach((key, value) -> value.appendTokenName(name));
         }
     }
 
@@ -130,7 +120,7 @@
         if (finalTokenName != null)
             result.append("! ");
         if (actions.size() == 1)
-            result.append(actions.keySet().toArray()[0].toString() + actions.values().toArray()[0].toString());
+            result.append(actions.keySet().toArray()[0].toString()).append(actions.values().toArray()[0].toString());
         if (actions.size() > 1) {
             result.append(" ( ");
             for (Map.Entry<Rule, LexerNode> action : actions.entrySet()) {
@@ -146,7 +136,7 @@
     }
 
     public String toJava() {
-        StringBuffer result = new StringBuffer();
+        StringBuilder result = new StringBuilder();
         if (numberOfRuleChar() > 2) {
             result.append(toJavaSingleCharRules());
             result.append(toJavaComplexRules(false));
@@ -154,10 +144,10 @@
             result.append(toJavaComplexRules(true));
         }
         if (this.finalTokenName != null) {
-            result.append("return " + TOKEN_PREFIX + finalTokenName + ";\n");
+            result.append("return ").append(TOKEN_PREFIX).append(finalTokenName).append(";\n");
         } else if (ongoingParsing != null) {
             String ongoingParsingArgs = collectionJoin(ongoingParsing, ',');
-            result.append("return parseError(" + ongoingParsingArgs + ");\n");
+            result.append("return parseError(").append(ongoingParsingArgs).append(");\n");
         }
         return result.toString();
     }
@@ -172,12 +162,12 @@
     }
 
     private String toJavaSingleCharRules() {
-        StringBuffer result = new StringBuffer();
+        StringBuilder result = new StringBuilder();
         result.append("switch(currentChar){\n");
         for (Map.Entry<Rule, LexerNode> action : actions.entrySet()) {
             if (action.getKey() instanceof RuleChar) {
                 RuleChar rule = (RuleChar) action.getKey();
-                result.append("case '" + rule.expectedChar() + "':\n");
+                result.append("case '").append(rule.expectedChar()).append("':\n");
                 result.append(rule.javaAction()).append("\n");
                 result.append(action.getValue().toJava());
             }
@@ -187,7 +177,7 @@
     }
 
     private String toJavaComplexRules(boolean all) {
-        StringBuffer result = new StringBuffer();
+        StringBuilder result = new StringBuilder();
         for (Map.Entry<Rule, LexerNode> action : actions.entrySet()) {
             if (!all && action.getKey() instanceof RuleChar)
                 continue;
@@ -244,7 +234,7 @@
             ongoingParsingArgs.append(token);
             ongoingParsingArgs.append(c);
         }
-        if (ongoingParsing.size() > 0) {
+        if (!ongoingParsing.isEmpty()) {
             ongoingParsingArgs.deleteCharAt(ongoingParsingArgs.length() - 1);
         }
         return ongoingParsingArgs.toString();
diff --git a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/MetadataCache.java b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/MetadataCache.java
index 08ca03b..8f88ca7 100644
--- a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/MetadataCache.java
+++ b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/MetadataCache.java
@@ -376,9 +376,7 @@
             if (m == null) {
                 return retDatasets;
             }
-            for (Map.Entry<String, Dataset> entry : m.entrySet()) {
-                retDatasets.add(entry.getValue());
-            }
+            m.forEach((key, value) -> retDatasets.add(value));
             return retDatasets;
         }
     }
diff --git a/asterixdb/asterix-replication/src/main/java/org/apache/asterix/replication/management/ReplicationManager.java b/asterixdb/asterix-replication/src/main/java/org/apache/asterix/replication/management/ReplicationManager.java
index da45e42..126114b 100644
--- a/asterixdb/asterix-replication/src/main/java/org/apache/asterix/replication/management/ReplicationManager.java
+++ b/asterixdb/asterix-replication/src/main/java/org/apache/asterix/replication/management/ReplicationManager.java
@@ -509,7 +509,7 @@
             i++;
         }
 
-        /**
+        /*
          * establish log replication handshake
          */
         ByteBuffer handshakeBuffer = ByteBuffer.allocate(ReplicationProtocol.REPLICATION_REQUEST_TYPE_SIZE)
@@ -563,7 +563,7 @@
             LOGGER.info("TxnLogReplicator thread was terminated.");
         }
 
-        /**
+        /*
          * End log replication handshake (by sending a dummy log with a single byte)
          */
         ByteBuffer endLogRepHandshake = ByteBuffer.allocate(Integer.SIZE + 1).putInt(1).put((byte) 0);
@@ -602,7 +602,7 @@
             }
         }
 
-        /**
+        /*
          * Close log replication sockets
          */
         ByteBuffer goodbyeBuffer = ReplicationProtocol.getGoodbyeBuffer();
@@ -914,7 +914,7 @@
         //stop replication thread afters all jobs/logs have been processed
         suspendReplication(false);
 
-        /**
+        /*
          * If this node has any remote replicas, it needs to inform them
          * that it is shutting down.
          */
@@ -923,7 +923,7 @@
             sendShutdownNotifiction();
         }
 
-        /**
+        /*
          * If this node has any remote primary replicas, then it needs to wait
          * until all of them send the shutdown notification.
          */
@@ -1051,7 +1051,7 @@
                     ReplicationProtocol.sendGoodbye(socketChannel);
                 }
 
-                /**
+                /*
                  * 4. update the LSN_MAP for indexes that were not flushed
                  * to the current append LSN to indicate no operations happened
                  * since the checkpoint start.
diff --git a/asterixdb/asterix-replication/src/main/java/org/apache/asterix/replication/recovery/RemoteRecoveryManager.java b/asterixdb/asterix-replication/src/main/java/org/apache/asterix/replication/recovery/RemoteRecoveryManager.java
index 7c7a050..df17987 100644
--- a/asterixdb/asterix-replication/src/main/java/org/apache/asterix/replication/recovery/RemoteRecoveryManager.java
+++ b/asterixdb/asterix-replication/src/main/java/org/apache/asterix/replication/recovery/RemoteRecoveryManager.java
@@ -97,10 +97,10 @@
         Map<String, Set<String>> recoveryList = new HashMap<>();
 
         //3. find best candidate to recover from per lost replica data
-        for (Entry<String, Set<String>> entry : recoveryCandidates.entrySet()) {
+        recoveryCandidates.forEach((key, value) -> {
             int winnerScore = -1;
             String winner = "";
-            for (String node : entry.getValue()) {
+            for (String node : value) {
 
                 int nodeScore = candidatesScore.get(node);
 
@@ -111,14 +111,14 @@
             }
 
             if (recoveryList.containsKey(winner)) {
-                recoveryList.get(winner).add(entry.getKey());
+                recoveryList.get(winner).add(key);
             } else {
                 Set<String> nodesToRecover = new HashSet<>();
-                nodesToRecover.add(entry.getKey());
+                nodesToRecover.add(key);
                 recoveryList.put(winner, nodesToRecover);
             }
 
-        }
+        });
 
         return recoveryList;
     }
@@ -146,7 +146,7 @@
 
     @Override
     public void takeoverPartitons(Integer[] partitions) throws IOException, ACIDException {
-        /**
+        /*
          * TODO even though the takeover is always expected to succeed,
          * in case of any failure during the takeover, the CC should be
          * notified that the takeover failed.
@@ -227,7 +227,7 @@
                 (ReplicaResourcesManager) runtimeContext.getReplicaResourcesManager();
         Map<String, ClusterPartition[]> nodePartitions = runtimeContext.getMetadataProperties().getNodePartitions();
 
-        /**
+        /*
          * for each lost partition, get the remaining files from replicas
          * to complete the failback process.
          */
@@ -251,7 +251,7 @@
                 replicationManager.requestReplicaFiles(replicaId, partitionsToRecover, existingFiles);
             }
         } catch (IOException e) {
-            /**
+            /*
              * in case of failure during failback completion process we need to construct a new plan
              * and get all the files from the start since the remote replicas will change in the new plan.
              */
diff --git a/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/utils/ClusterStateManager.java b/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/utils/ClusterStateManager.java
index 6e55fd2..ac83b71 100644
--- a/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/utils/ClusterStateManager.java
+++ b/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/utils/ClusterStateManager.java
@@ -462,11 +462,11 @@
     private void updateNodeConfig(String nodeId, Map<IOption, Object> configuration) {
         ConfigManager configManager = ((ConfigManagerApplicationConfig) appCtx.getServiceContext().getAppConfig())
                 .getConfigManager();
-        for (Map.Entry<IOption, Object> entry : configuration.entrySet()) {
-            if (entry.getKey().section() == Section.NC) {
-                configManager.set(nodeId, entry.getKey(), entry.getValue());
+        configuration.forEach((key, value) -> {
+            if (key.section() == Section.NC) {
+                configManager.set(nodeId, key, value);
             }
-        }
+        });
     }
 
 }
diff --git a/asterixdb/asterix-test-framework/src/main/java/org/apache/asterix/testframework/template/TemplateHelper.java b/asterixdb/asterix-test-framework/src/main/java/org/apache/asterix/testframework/template/TemplateHelper.java
index b3f26fd..d2f52dc 100644
--- a/asterixdb/asterix-test-framework/src/main/java/org/apache/asterix/testframework/template/TemplateHelper.java
+++ b/asterixdb/asterix-test-framework/src/main/java/org/apache/asterix/testframework/template/TemplateHelper.java
@@ -41,15 +41,15 @@
 
     private TemplateHelper() {
         registerReplacement(LoremIpsumReplacement.INSTANCE);
-        StringBuffer pattern = null;
-        for (Map.Entry<String, TemplateReplacement> entry : replacements.entrySet()) {
-            if (pattern == null) {
-                pattern = new StringBuffer("%(");
+        StringBuilder pattern = new StringBuilder();
+        replacements.forEach((key, value) -> {
+            if (pattern.length() == 0) {
+                pattern.append("%(");
             } else {
                 pattern.append("|");
             }
-            pattern.append(entry.getKey());
-        }
+            pattern.append(key);
+        });
         pattern.append(")[^%]*%");
         replacementPattern = Pattern.compile(pattern.toString());
     }
diff --git a/asterixdb/asterix-transactions/src/main/java/org/apache/asterix/transaction/management/resource/PersistentLocalResourceRepository.java b/asterixdb/asterix-transactions/src/main/java/org/apache/asterix/transaction/management/resource/PersistentLocalResourceRepository.java
index 85ad6b4..5666b48 100644
--- a/asterixdb/asterix-transactions/src/main/java/org/apache/asterix/transaction/management/resource/PersistentLocalResourceRepository.java
+++ b/asterixdb/asterix-transactions/src/main/java/org/apache/asterix/transaction/management/resource/PersistentLocalResourceRepository.java
@@ -34,7 +34,6 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Set;
 import java.util.SortedMap;
 import java.util.concurrent.ConcurrentHashMap;
@@ -128,9 +127,8 @@
                 .append(Character.LINE_SEPARATOR).append(ioManager.getClass().getSimpleName()).append(':')
                 .append(Character.LINE_SEPARATOR).append(ioManager.toString()).append(Character.LINE_SEPARATOR)
                 .append("Cached Resources:").append(Character.LINE_SEPARATOR);
-        for (Entry<String, LocalResource> pair : resourceCache.asMap().entrySet()) {
-            aString.append(pair.getKey()).append("->").append(pair.getValue()).append(Character.LINE_SEPARATOR);
-        }
+        resourceCache.asMap().forEach(
+                (key, value) -> aString.append(key).append("->").append(value).append(Character.LINE_SEPARATOR));
         return aString.toString();
     }
 
diff --git a/asterixdb/asterix-yarn/src/main/java/org/apache/asterix/aoya/AsterixApplicationMaster.java b/asterixdb/asterix-yarn/src/main/java/org/apache/asterix/aoya/AsterixApplicationMaster.java
index 47cf3b3..4a900e1 100644
--- a/asterixdb/asterix-yarn/src/main/java/org/apache/asterix/aoya/AsterixApplicationMaster.java
+++ b/asterixdb/asterix-yarn/src/main/java/org/apache/asterix/aoya/AsterixApplicationMaster.java
@@ -230,10 +230,10 @@
 
         LOG.info("Dump debug output");
         Map<String, String> envs = System.getenv();
-        for (Map.Entry<String, String> env : envs.entrySet()) {
-            LOG.info("System env: key=" + env.getKey() + ", val=" + env.getValue());
-            System.out.println("System env: key=" + env.getKey() + ", val=" + env.getValue());
-        }
+        envs.forEach((key, value) -> {
+            LOG.info("System env: key=" + key + ", val=" + value);
+            System.out.println("System env: key=" + key + ", val=" + value);
+        });
 
         String cmd = "ls -alhLR";
         Runtime run = Runtime.getRuntime();
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/expressions/ConstantExpression.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/expressions/ConstantExpression.java
index 8f55632..689d51c 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/expressions/ConstantExpression.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/expressions/ConstantExpression.java
@@ -22,7 +22,6 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 
 import org.apache.commons.lang3.mutable.Mutable;
 import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
@@ -172,10 +171,7 @@
     @Override
     public AbstractLogicalExpression cloneExpression() {
         Map<Object, IExpressionAnnotation> m = new HashMap<>();
-        for (Entry<Object, IExpressionAnnotation> entry : annotationMap.entrySet()) {
-            IExpressionAnnotation annot2 = entry.getValue().copy();
-            m.put(entry.getKey(), annot2);
-        }
+        annotationMap.forEach((key, value1) -> m.put(key, value1.copy()));
         ConstantExpression c = new ConstantExpression(value);
         c.annotationMap = m;
         return c;
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/FDsAndEquivClassesVisitor.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/FDsAndEquivClassesVisitor.java
index 4843f81..f800be8 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/FDsAndEquivClassesVisitor.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/FDsAndEquivClassesVisitor.java
@@ -25,7 +25,6 @@
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Set;
 
 import org.apache.commons.lang3.mutable.Mutable;
@@ -49,11 +48,11 @@
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AggregateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AssignOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.DataSourceScanOperator;
+import org.apache.hyracks.algebricks.core.algebra.operators.logical.DelegateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.DistinctOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.DistributeResultOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.EmptyTupleSourceOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.ExchangeOperator;
-import org.apache.hyracks.algebricks.core.algebra.operators.logical.DelegateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.GroupByOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.IndexInsertDeleteUpsertOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.InnerJoinOperator;
@@ -662,26 +661,24 @@
         // equivalent
         // class should still be propagated (kept).
         Set<LogicalVariable> usedVarSet = new HashSet<LogicalVariable>(usedVariables);
-        for (Entry<LogicalVariable, EquivalenceClass> entry : chldClasses.entrySet()) {
-            EquivalenceClass ec = entry.getValue();
+        chldClasses.forEach((key, ec) -> {
             for (ILogicalExpression expr : ec.getExpressionMembers()) {
-                Set<LogicalVariable> exprUsedVars = new HashSet<LogicalVariable>();
+                Set<LogicalVariable> exprUsedVars = new HashSet<>();
                 expr.getUsedVariables(exprUsedVars);
                 exprUsedVars.retainAll(usedVarSet);
                 // Check if the expression member uses a used variable.
                 if (!exprUsedVars.isEmpty()) {
-                    for (LogicalVariable v : ec.getMembers()) {
+                    // If variable members contain a used variable, the representative variable should be a used
+                    // variable.
+                    ec.getMembers().forEach(v -> {
                         eqClasses.put(v, ec);
-                        // If variable members contain a used variable, the
-                        // representative
-                        // variable should be a used variable.
                         if (usedVarSet.contains(v)) {
                             ec.setVariableRepresentative(v);
                         }
-                    }
+                    });
                 }
             }
-        }
+        });
 
         List<FunctionalDependency> chldFds = getOrComputeFDs(op2, ctx);
         for (FunctionalDependency fd : chldFds) {
@@ -786,8 +783,7 @@
             LogicalVariable var = assignVars.get(assignVarIndex);
             ILogicalExpression expr = assignExprs.get(assignVarIndex).getValue();
             Map<LogicalVariable, EquivalenceClass> newVarEqcMap = new HashMap<LogicalVariable, EquivalenceClass>();
-            for (Entry<LogicalVariable, EquivalenceClass> entry : eqClasses.entrySet()) {
-                EquivalenceClass eqc = entry.getValue();
+            eqClasses.forEach((key, eqc) -> {
                 // If the equivalence class contains the right-hand-side
                 // expression,
                 // the left-hand-side variable is added into the equivalence
@@ -795,9 +791,9 @@
                 if (eqc.contains(expr)) {
                     eqc.addMember(var);
                     newVarEqcMap.put(var, eqc); // Add var as a map key for the
-                                                // equivalence class.
+                    // equivalence class.
                 }
-            }
+            });
             eqClasses.putAll(newVarEqcMap);
         }
     }
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/IsomorphismOperatorVisitor.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/IsomorphismOperatorVisitor.java
index b3b9da1..0c53685 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/IsomorphismOperatorVisitor.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/IsomorphismOperatorVisitor.java
@@ -23,6 +23,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Objects;
 
 import org.apache.commons.lang3.mutable.Mutable;
 import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
@@ -37,11 +38,11 @@
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AggregateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AssignOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.DataSourceScanOperator;
+import org.apache.hyracks.algebricks.core.algebra.operators.logical.DelegateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.DistinctOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.DistributeResultOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.EmptyTupleSourceOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.ExchangeOperator;
-import org.apache.hyracks.algebricks.core.algebra.operators.logical.DelegateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.GroupByOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.IndexInsertDeleteUpsertOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.InnerJoinOperator;
@@ -633,15 +634,13 @@
         variableMapping.clear();
         IsomorphismUtilities.mapVariablesTopDown(op, argOp, variableMapping);
 
-        List<LogicalVariable> liveVars = new ArrayList<LogicalVariable>();
-        if (argOp.getInputs().size() > 0) {
-            for (int i = 0; i < argOp.getInputs().size(); i++) {
-                VariableUtilities.getLiveVariables(argOp.getInputs().get(i).getValue(), liveVars);
-            }
+        List<LogicalVariable> liveVars = new ArrayList<>();
+        for (int i = 0; i < argOp.getInputs().size(); i++) {
+            VariableUtilities.getLiveVariables(argOp.getInputs().get(i).getValue(), liveVars);
         }
-        List<LogicalVariable> producedVars = new ArrayList<LogicalVariable>();
+        List<LogicalVariable> producedVars = new ArrayList<>();
         VariableUtilities.getProducedVariables(argOp, producedVars);
-        List<LogicalVariable> producedVarsNew = new ArrayList<LogicalVariable>();
+        List<LogicalVariable> producedVarsNew = new ArrayList<>();
         VariableUtilities.getProducedVariables(op, producedVarsNew);
 
         if (producedVars.size() != producedVarsNew.size()) {
@@ -671,14 +670,7 @@
     }
 
     private static boolean variableEqual(LogicalVariable var, LogicalVariable varArg) {
-        if (var == null && varArg == null) {
-            return true;
-        }
-        if (var.equals(varArg)) {
-            return true;
-        } else {
-            return false;
-        }
+        return Objects.equals(var, varArg);
     }
 
     @Override
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/IsomorphismVariableMappingVisitor.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/IsomorphismVariableMappingVisitor.java
index 52d8e64..2caa252 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/IsomorphismVariableMappingVisitor.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/IsomorphismVariableMappingVisitor.java
@@ -22,7 +22,6 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Set;
 
 import org.apache.commons.lang3.mutable.Mutable;
@@ -34,17 +33,16 @@
 import org.apache.hyracks.algebricks.core.algebra.base.ILogicalOperator;
 import org.apache.hyracks.algebricks.core.algebra.base.ILogicalPlan;
 import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable;
-import org.apache.hyracks.algebricks.core.algebra.expressions.AbstractLogicalExpression;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractAssignOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractOperatorWithNestedPlans;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AggregateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.AssignOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.DataSourceScanOperator;
+import org.apache.hyracks.algebricks.core.algebra.operators.logical.DelegateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.DistinctOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.DistributeResultOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.EmptyTupleSourceOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.ExchangeOperator;
-import org.apache.hyracks.algebricks.core.algebra.operators.logical.DelegateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.GroupByOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.IndexInsertDeleteUpsertOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.InnerJoinOperator;
@@ -435,11 +433,9 @@
     }
 
     private Mutable<ILogicalExpression> copyExpressionAndSubtituteVars(Mutable<ILogicalExpression> expr) {
-        ILogicalExpression copy = ((AbstractLogicalExpression) expr.getValue()).cloneExpression();
-        for (Entry<LogicalVariable, LogicalVariable> entry : variableMapping.entrySet()) {
-            copy.substituteVar(entry.getKey(), entry.getValue());
-        }
-        return new MutableObject<ILogicalExpression>(copy);
+        ILogicalExpression copy = expr.getValue().cloneExpression();
+        variableMapping.forEach(copy::substituteVar);
+        return new MutableObject<>(copy);
     }
 
     private void mapVariablesForUnion(ILogicalOperator op, ILogicalOperator arg) {
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/LogicalExpressionDeepCopyWithNewVariablesVisitor.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/LogicalExpressionDeepCopyWithNewVariablesVisitor.java
index cef387a..24c5162 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/LogicalExpressionDeepCopyWithNewVariablesVisitor.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/LogicalExpressionDeepCopyWithNewVariablesVisitor.java
@@ -65,10 +65,7 @@
     private void deepCopyAnnotations(AbstractFunctionCallExpression src, AbstractFunctionCallExpression dest) {
         Map<Object, IExpressionAnnotation> srcAnnotations = src.getAnnotations();
         Map<Object, IExpressionAnnotation> destAnnotations = dest.getAnnotations();
-        for (Map.Entry<Object, IExpressionAnnotation> annotationEntry : srcAnnotations.entrySet()) {
-            IExpressionAnnotation annotation = annotationEntry.getValue().copy();
-            destAnnotations.put(annotationEntry.getKey(), annotation);
-        }
+        srcAnnotations.forEach((key, value) -> destAnnotations.put(key, value.copy()));
     }
 
     private void deepCopyOpaqueParameters(AbstractFunctionCallExpression src, AbstractFunctionCallExpression dest) {
@@ -85,7 +82,7 @@
 
     public MutableObject<ILogicalExpression> deepCopyExpressionReference(Mutable<ILogicalExpression> exprRef)
             throws AlgebricksException {
-        return new MutableObject<ILogicalExpression>(deepCopy(exprRef.getValue()));
+        return new MutableObject<>(deepCopy(exprRef.getValue()));
     }
 
     // TODO return List<...>
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/LogicalOperatorDeepCopyWithNewVariablesVisitor.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/LogicalOperatorDeepCopyWithNewVariablesVisitor.java
index 934577f..a75e7d6 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/LogicalOperatorDeepCopyWithNewVariablesVisitor.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/visitors/LogicalOperatorDeepCopyWithNewVariablesVisitor.java
@@ -22,7 +22,6 @@
 import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
-import java.util.Map;
 import java.util.Set;
 
 import org.apache.commons.lang3.mutable.Mutable;
@@ -54,6 +53,7 @@
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.MaterializeOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.NestedTupleSourceOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.OrderOperator;
+import org.apache.hyracks.algebricks.core.algebra.operators.logical.OrderOperator.IOrder;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.ProjectOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.ReplicateOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.RunningAggregateOperator;
@@ -65,7 +65,6 @@
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.UnionAllOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.UnnestMapOperator;
 import org.apache.hyracks.algebricks.core.algebra.operators.logical.UnnestOperator;
-import org.apache.hyracks.algebricks.core.algebra.operators.logical.OrderOperator.IOrder;
 import org.apache.hyracks.algebricks.core.algebra.plan.ALogicalPlanImpl;
 import org.apache.hyracks.algebricks.core.algebra.properties.FunctionalDependency;
 import org.apache.hyracks.algebricks.core.algebra.typing.ITypingContext;
@@ -179,7 +178,7 @@
 
     private Mutable<ILogicalOperator> deepCopyOperatorReference(Mutable<ILogicalOperator> opRef, ILogicalOperator arg)
             throws AlgebricksException {
-        return new MutableObject<ILogicalOperator>(deepCopy(opRef.getValue(), arg));
+        return new MutableObject<>(deepCopy(opRef.getValue(), arg));
     }
 
     private List<Mutable<ILogicalOperator>> deepCopyOperatorReferenceList(List<Mutable<ILogicalOperator>> list,
@@ -280,18 +279,18 @@
     }
 
     public void updatePrimaryKeys(IOptimizationContext context) {
-        for (Map.Entry<LogicalVariable, LogicalVariable> entry : inputVarToOutputVarMapping.entrySet()) {
-            List<LogicalVariable> primaryKey = context.findPrimaryKey(entry.getKey());
+        inputVarToOutputVarMapping.forEach((key, value) -> {
+            List<LogicalVariable> primaryKey = context.findPrimaryKey(key);
             if (primaryKey != null) {
-                List<LogicalVariable> head = new ArrayList<LogicalVariable>();
+                List<LogicalVariable> head = new ArrayList<>();
                 for (LogicalVariable variable : primaryKey) {
                     head.add(inputVarToOutputVarMapping.get(variable));
                 }
-                List<LogicalVariable> tail = new ArrayList<LogicalVariable>(1);
-                tail.add(entry.getValue());
+                List<LogicalVariable> tail = new ArrayList<>(1);
+                tail.add(value);
                 context.addPrimaryKey(new FunctionalDependency(head, tail));
             }
-        }
+        });
     }
 
     public LogicalVariable varCopy(LogicalVariable var) throws AlgebricksException {
@@ -398,7 +397,7 @@
     public ILogicalOperator visitNestedTupleSourceOperator(NestedTupleSourceOperator op, ILogicalOperator arg)
             throws AlgebricksException {
         Mutable<ILogicalOperator> dataSourceReference = arg == null ? op.getDataSourceReference()
-                : new MutableObject<ILogicalOperator>(arg);
+                : new MutableObject<>(arg);
         NestedTupleSourceOperator opCopy = new NestedTupleSourceOperator(dataSourceReference);
         deepCopyInputsAnnotationsAndExecutionMode(op, arg, opCopy);
         return opCopy;
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/properties/UnorderedPartitionedProperty.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/properties/UnorderedPartitionedProperty.java
index 641557c..f59638c 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/properties/UnorderedPartitionedProperty.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/properties/UnorderedPartitionedProperty.java
@@ -70,11 +70,11 @@
 
     @Override
     public void substituteColumnVars(Map<LogicalVariable, LogicalVariable> varMap) {
-        for (Map.Entry<LogicalVariable, LogicalVariable> var : varMap.entrySet()) {
-            if (columnSet.remove(var.getKey())) {
-                columnSet.add(var.getValue());
+        varMap.forEach((key, value) -> {
+            if (columnSet.remove(key)) {
+                columnSet.add(value);
             }
-        }
+        });
     }
 
 }
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/jobgen/impl/PlanCompiler.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/jobgen/impl/PlanCompiler.java
index 2960903..f817cd6 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/jobgen/impl/PlanCompiler.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/jobgen/impl/PlanCompiler.java
@@ -22,7 +22,6 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 
 import org.apache.commons.lang3.mutable.Mutable;
 import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
@@ -98,13 +97,10 @@
     }
 
     private void reviseEdges(IHyracksJobBuilder builder) {
-        /**
+        /*
          * revise the edges for the case of replicate operator
          */
-        for (Entry<Mutable<ILogicalOperator>, List<Mutable<ILogicalOperator>>> entry : operatorVisitedToParents
-                .entrySet()) {
-            Mutable<ILogicalOperator> child = entry.getKey();
-            List<Mutable<ILogicalOperator>> parents = entry.getValue();
+        operatorVisitedToParents.forEach((child, parents) -> {
             if (parents.size() > 1) {
                 if (child.getValue().getOperatorTag() == LogicalOperatorTag.REPLICATE
                         || child.getValue().getOperatorTag() == LogicalOperatorTag.SPLIT) {
@@ -113,7 +109,8 @@
                         // make the order of the graph edges consistent with the order of rop's outputs
                         List<Mutable<ILogicalOperator>> outputs = rop.getOutputs();
                         for (Mutable<ILogicalOperator> parent : parents) {
-                            builder.contributeGraphEdge(child.getValue(), outputs.indexOf(parent), parent.getValue(), 0);
+                            builder.contributeGraphEdge(child.getValue(), outputs.indexOf(parent), parent.getValue(),
+                                    0);
                         }
                     } else {
                         int i = 0;
@@ -124,6 +121,6 @@
                     }
                 }
             }
-        }
+        });
     }
 }
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/utils/DotFormatBuilder.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/utils/DotFormatBuilder.java
index 1bbda27..9c452bf 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/utils/DotFormatBuilder.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/utils/DotFormatBuilder.java
@@ -22,7 +22,6 @@
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Map;
 import java.util.Set;
 
 public class DotFormatBuilder {
@@ -129,9 +128,7 @@
         public String toString() {
             StringBuilder nodeString = new StringBuilder();
             nodeString.append(nodeId).append(" [");
-            for (Map.Entry attribute : attributes.entrySet()) {
-                nodeString.append(attribute.getKey()).append("=").append(attribute.getValue()).append(",");
-            }
+            attributes.forEach((key, value) -> nodeString.append(key).append("=").append(value).append(","));
             // remove last ","
             if (nodeString.charAt(nodeString.length() - 1) == ',') {
                 nodeString.deleteCharAt(nodeString.length() - 1);
@@ -186,9 +183,7 @@
         public String toString() {
             StringBuilder edgeString = new StringBuilder();
             edgeString.append(source.getNodeId()).append("->").append(destination.getNodeId()).append(" [");
-            for (Map.Entry attribute : attributes.entrySet()) {
-                edgeString.append(attribute.getKey()).append("=").append(attribute.getValue()).append(",");
-            }
+            attributes.forEach((key, value) -> edgeString.append(key).append("=").append(value).append(","));
             // remove last ","
             if (edgeString.charAt(edgeString.length() - 1) == ',') {
                 edgeString.deleteCharAt(edgeString.length() - 1);
diff --git a/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/client/impl/JobActivityGraphBuilder.java b/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/client/impl/JobActivityGraphBuilder.java
index 1c2b9b5..084626e 100644
--- a/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/client/impl/JobActivityGraphBuilder.java
+++ b/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/client/impl/JobActivityGraphBuilder.java
@@ -103,12 +103,8 @@
     public void finish() {
         Map<ConnectorDescriptorId, Pair<Pair<IActivity, Integer>, Pair<IActivity, Integer>>> caMap = jag
                 .getConnectorActivityMap();
-        for (Map.Entry<ConnectorDescriptorId, Pair<IActivity, Integer>> e : connectorProducerMap.entrySet()) {
-            ConnectorDescriptorId cdId = e.getKey();
-            Pair<IActivity, Integer> producer = e.getValue();
-            Pair<IActivity, Integer> consumer = connectorConsumerMap.get(cdId);
-            caMap.put(cdId, Pair.of(producer, consumer));
-        }
+        connectorProducerMap
+                .forEach((cdId, producer) -> caMap.put(cdId, Pair.of(producer, connectorConsumerMap.get(cdId))));
     }
 
     private <K, V> void addToValueSet(Map<K, Set<V>> map, K n1, V n2) {
diff --git a/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/job/JobSpecification.java b/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/job/JobSpecification.java
index 2cf96c2..9f66080 100644
--- a/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/job/JobSpecification.java
+++ b/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/job/JobSpecification.java
@@ -309,11 +309,7 @@
     }
 
     private <K, V> void insertIntoIndexedMap(Map<K, List<V>> map, K key, int index, V value) {
-        List<V> vList = map.get(key);
-        if (vList == null) {
-            vList = new ArrayList<>();
-            map.put(key, vList);
-        }
+        List<V> vList = map.computeIfAbsent(key, k -> new ArrayList<>());
         extend(vList, index);
         vList.set(index, value);
     }
@@ -322,9 +318,9 @@
     public String toString() {
         StringBuilder buffer = new StringBuilder();
 
-        for (Map.Entry<OperatorDescriptorId, IOperatorDescriptor> e : opMap.entrySet()) {
-            buffer.append(e.getKey().getId()).append(" : ").append(e.getValue().toString()).append("\n");
-            List<IConnectorDescriptor> inputs = opInputMap.get(e.getKey());
+        opMap.forEach((key, value) -> {
+            buffer.append(key.getId()).append(" : ").append(value.toString()).append("\n");
+            List<IConnectorDescriptor> inputs = opInputMap.get(key);
             if (inputs != null && !inputs.isEmpty()) {
                 buffer.append("   Inputs:\n");
                 for (IConnectorDescriptor c : inputs) {
@@ -332,7 +328,7 @@
                             .append("\n");
                 }
             }
-            List<IConnectorDescriptor> outputs = opOutputMap.get(e.getKey());
+            List<IConnectorDescriptor> outputs = opOutputMap.get(key);
             if (outputs != null && !outputs.isEmpty()) {
                 buffer.append("   Outputs:\n");
                 for (IConnectorDescriptor c : outputs) {
@@ -340,7 +336,7 @@
                             .append("\n");
                 }
             }
-        }
+        });
 
         buffer.append("\n").append("Constraints:\n").append(userConstraints);
 
@@ -352,8 +348,8 @@
         ObjectNode jjob = om.createObjectNode();
 
         ArrayNode jopArray = om.createArrayNode();
-        for (Map.Entry<OperatorDescriptorId, IOperatorDescriptor> e : opMap.entrySet()) {
-            ObjectNode op = e.getValue().toJSON();
+        opMap.forEach((key, value) -> {
+            ObjectNode op = value.toJSON();
             if (!userConstraints.isEmpty()) {
                 // Add operator partition constraints to each JSON operator.
                 ObjectNode pcObject = om.createObjectNode();
@@ -364,12 +360,12 @@
                     ExpressionTag tag = constraint.getLValue().getTag();
                     if (tag == ExpressionTag.PARTITION_COUNT) {
                         PartitionCountExpression pce = (PartitionCountExpression) constraint.getLValue();
-                        if (e.getKey() == pce.getOperatorDescriptorId()) {
+                        if (key == pce.getOperatorDescriptorId()) {
                             pcObject.put("count", getConstraintExpressionRValue(constraint));
                         }
                     } else if (tag == ExpressionTag.PARTITION_LOCATION) {
                         PartitionLocationExpression ple = (PartitionLocationExpression) constraint.getLValue();
-                        if (e.getKey() == ple.getOperatorDescriptorId()) {
+                        if (key == ple.getOperatorDescriptorId()) {
                             pleObject.put(Integer.toString(ple.getPartition()),
                                     getConstraintExpressionRValue(constraint));
                         }
@@ -383,23 +379,23 @@
                 }
             }
             jopArray.add(op);
-        }
+        });
         jjob.set("operators", jopArray);
 
         ArrayNode jcArray = om.createArrayNode();
-        for (Map.Entry<ConnectorDescriptorId, IConnectorDescriptor> e : connMap.entrySet()) {
+        connMap.forEach((key, value) -> {
             ObjectNode conn = om.createObjectNode();
             Pair<Pair<IOperatorDescriptor, Integer>, Pair<IOperatorDescriptor, Integer>> connection =
-                    connectorOpMap.get(e.getKey());
+                    connectorOpMap.get(key);
             if (connection != null) {
                 conn.put("in-operator-id", connection.getLeft().getLeft().getOperatorId().toString());
                 conn.put("in-operator-port", connection.getLeft().getRight().intValue());
                 conn.put("out-operator-id", connection.getRight().getLeft().getOperatorId().toString());
                 conn.put("out-operator-port", connection.getRight().getRight().intValue());
             }
-            conn.set("connector", e.getValue().toJSON());
+            conn.set("connector", value.toJSON());
             jcArray.add(conn);
-        }
+        });
         jjob.set("connectors", jcArray);
 
         return jjob;
diff --git a/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/rewriter/ActivityClusterGraphRewriter.java b/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/rewriter/ActivityClusterGraphRewriter.java
index 20f128d..7cdb300 100644
--- a/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/rewriter/ActivityClusterGraphRewriter.java
+++ b/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/rewriter/ActivityClusterGraphRewriter.java
@@ -29,7 +29,6 @@
 import java.util.Set;
 
 import org.apache.commons.lang3.tuple.Pair;
-
 import org.apache.hyracks.api.dataflow.ActivityId;
 import org.apache.hyracks.api.dataflow.ConnectorDescriptorId;
 import org.apache.hyracks.api.dataflow.IActivity;
@@ -37,7 +36,6 @@
 import org.apache.hyracks.api.dataflow.value.RecordDescriptor;
 import org.apache.hyracks.api.job.ActivityCluster;
 import org.apache.hyracks.api.job.ActivityClusterGraph;
-import org.apache.hyracks.api.job.ActivityClusterId;
 import org.apache.hyracks.api.rewriter.runtime.SuperActivity;
 
 /**
@@ -65,12 +63,10 @@
         acg.getActivityMap().clear();
         acg.getConnectorMap().clear();
         Map<IActivity, SuperActivity> invertedActivitySuperActivityMap = new HashMap<>();
-        for (Entry<ActivityClusterId, ActivityCluster> entry : acg.getActivityClusterMap().entrySet()) {
-            rewriteIntraActivityCluster(entry.getValue(), invertedActivitySuperActivityMap);
-        }
-        for (Entry<ActivityClusterId, ActivityCluster> entry : acg.getActivityClusterMap().entrySet()) {
-            rewriteInterActivityCluster(entry.getValue(), invertedActivitySuperActivityMap);
-        }
+        acg.getActivityClusterMap()
+                .forEach((key, value) -> rewriteIntraActivityCluster(value, invertedActivitySuperActivityMap));
+        acg.getActivityClusterMap()
+                .forEach((key, value) -> rewriteInterActivityCluster(value, invertedActivitySuperActivityMap));
         invertedActivitySuperActivityMap.clear();
     }
 
@@ -84,14 +80,11 @@
             Map<IActivity, SuperActivity> invertedActivitySuperActivityMap) {
         Map<ActivityId, Set<ActivityId>> blocked2BlockerMap = ac.getBlocked2BlockerMap();
         Map<ActivityId, ActivityId> invertedAid2SuperAidMap = new HashMap<>();
-        for (Entry<IActivity, SuperActivity> entry : invertedActivitySuperActivityMap.entrySet()) {
-            invertedAid2SuperAidMap.put(entry.getKey().getActivityId(), entry.getValue().getActivityId());
-        }
+        invertedActivitySuperActivityMap
+                .forEach((key, value) -> invertedAid2SuperAidMap.put(key.getActivityId(), value.getActivityId()));
         Map<ActivityId, Set<ActivityId>> replacedBlocked2BlockerMap = new HashMap<>();
-        for (Entry<ActivityId, Set<ActivityId>> entry : blocked2BlockerMap.entrySet()) {
-            ActivityId blocked = entry.getKey();
+        blocked2BlockerMap.forEach((blocked, blockers) -> {
             ActivityId replacedBlocked = invertedAid2SuperAidMap.get(blocked);
-            Set<ActivityId> blockers = entry.getValue();
             Set<ActivityId> replacedBlockers = null;
             if (blockers != null) {
                 replacedBlockers = new HashSet<>();
@@ -113,7 +106,7 @@
                     replacedBlocked2BlockerMap.put(replacedBlocked, existingBlockers);
                 }
             }
-        }
+        });
         blocked2BlockerMap.clear();
         blocked2BlockerMap.putAll(replacedBlocked2BlockerMap);
     }
@@ -136,23 +129,21 @@
         Map<ActivityId, SuperActivity> superActivities = new HashMap<>();
         Map<ActivityId, Queue<IActivity>> toBeExpendedMap = new HashMap<>();
 
-        /**
+        /*
          * Build the initial super activities
          */
-        for (Entry<ActivityId, IActivity> entry : activities.entrySet()) {
-            ActivityId activityId = entry.getKey();
-            IActivity activity = entry.getValue();
+        activities.forEach((activityId, activity) -> {
             if (activityInputMap.get(activityId) == null) {
                 startActivities.put(activityId, activity);
-                /**
+                /*
                  * use the start activity's id as the id of the super activity
                  */
                 createNewSuperActivity(ac, superActivities, toBeExpendedMap, invertedActivitySuperActivityMap,
                         activityId, activity);
             }
-        }
+        });
 
-        /**
+        /*
          * expand one-to-one connected activity cluster by the BFS order.
          * after the while-loop, the original activities are partitioned
          * into equivalent classes, one-per-super-activity.
@@ -165,19 +156,19 @@
                 ActivityId superActivityId = entry.getKey();
                 SuperActivity superActivity = entry.getValue();
 
-                /**
+                /*
                  * for the case where the super activity has already been swallowed
                  */
                 if (superActivities.get(superActivityId) == null) {
                     continue;
                 }
 
-                /**
+                /*
                  * expend the super activity
                  */
                 Queue<IActivity> toBeExpended = toBeExpendedMap.get(superActivityId);
                 if (toBeExpended == null) {
-                    /**
+                    /*
                      * Nothing to expand
                      */
                     continue;
@@ -191,7 +182,7 @@
                         IActivity newActivity = endPoints.getRight().getLeft();
                         SuperActivity existingSuperActivity = invertedActivitySuperActivityMap.get(newActivity);
                         if (outputConn.getClass().getName().contains(ONE_TO_ONE_CONNECTOR)) {
-                            /**
+                            /*
                              * expend the super activity cluster on an one-to-one out-bound connection
                              */
                             if (existingSuperActivity == null) {
@@ -199,13 +190,13 @@
                                 toBeExpended.add(newActivity);
                                 invertedActivitySuperActivityMap.put(newActivity, superActivity);
                             } else {
-                                /**
+                                /*
                                  * the two activities already in the same super activity
                                  */
                                 if (existingSuperActivity == superActivity) {
                                     continue;
                                 }
-                                /**
+                                /*
                                  * swallow an existing super activity
                                  */
                                 swallowExistingSuperActivity(superActivities, toBeExpendedMap,
@@ -214,7 +205,7 @@
                             }
                         } else {
                             if (existingSuperActivity == null) {
-                                /**
+                                /*
                                  * create new activity
                                  */
                                 createNewSuperActivity(ac, superActivities, toBeExpendedMap,
@@ -224,10 +215,10 @@
                     }
                 }
 
-                /**
+                /*
                  * remove the to-be-expended queue if it is empty
                  */
-                if (toBeExpended.size() == 0) {
+                if (toBeExpended.isEmpty()) {
                     toBeExpendedMap.remove(superActivityId);
                 }
             }
@@ -237,28 +228,25 @@
         Map<ConnectorDescriptorId, RecordDescriptor> connRecordDesc = ac.getConnectorRecordDescriptorMap();
         Map<SuperActivity, Integer> superActivityProducerPort = new HashMap<>();
         Map<SuperActivity, Integer> superActivityConsumerPort = new HashMap<>();
-        for (Entry<ActivityId, SuperActivity> entry : superActivities.entrySet()) {
-            superActivityProducerPort.put(entry.getValue(), 0);
-            superActivityConsumerPort.put(entry.getValue(), 0);
-        }
+        superActivities.forEach((key, value) -> {
+            superActivityProducerPort.put(value, 0);
+            superActivityConsumerPort.put(value, 0);
+        });
 
-        /**
+        /*
          * create a new activity cluster to replace the old activity cluster
          */
         ActivityCluster newActivityCluster = new ActivityCluster(acg, ac.getId());
         newActivityCluster.setConnectorPolicyAssignmentPolicy(ac.getConnectorPolicyAssignmentPolicy());
-        for (Entry<ActivityId, SuperActivity> entry : superActivities.entrySet()) {
-            newActivityCluster.addActivity(entry.getValue());
-            acg.getActivityMap().put(entry.getKey(), newActivityCluster);
-        }
+        superActivities.forEach((key, value) -> {
+            newActivityCluster.addActivity(value);
+            acg.getActivityMap().put(key, newActivityCluster);
+        });
 
-        /**
+        /*
          * Setup connectors: either inside a super activity or among super activities
          */
-        for (Entry<ConnectorDescriptorId, Pair<Pair<IActivity, Integer>, Pair<IActivity, Integer>>> entry : connectorActivityMap
-                .entrySet()) {
-            ConnectorDescriptorId connectorId = entry.getKey();
-            Pair<Pair<IActivity, Integer>, Pair<IActivity, Integer>> endPoints = entry.getValue();
+        connectorActivityMap.forEach((connectorId, endPoints) -> {
             IActivity producerActivity = endPoints.getLeft().getLeft();
             IActivity consumerActivity = endPoints.getRight().getLeft();
             int producerPort = endPoints.getLeft().getRight();
@@ -266,14 +254,14 @@
             RecordDescriptor recordDescriptor = connRecordDesc.get(connectorId);
             IConnectorDescriptor conn = connMap.get(connectorId);
             if (conn.getClass().getName().contains(ONE_TO_ONE_CONNECTOR)) {
-                /**
+                /*
                  * connection edge between inner activities
                  */
                 SuperActivity residingSuperActivity = invertedActivitySuperActivityMap.get(producerActivity);
                 residingSuperActivity.connect(conn, producerActivity, producerPort, consumerActivity, consumerPort,
                         recordDescriptor);
             } else {
-                /**
+                /*
                  * connection edge between super activities
                  */
                 SuperActivity producerSuperActivity = invertedActivitySuperActivityMap.get(producerActivity);
@@ -284,7 +272,7 @@
                 newActivityCluster.connect(conn, producerSuperActivity, producerSAPort, consumerSuperActivity,
                         consumerSAPort, recordDescriptor);
 
-                /**
+                /*
                  * bridge the port
                  */
                 producerSuperActivity.setClusterOutputIndex(producerSAPort, producerActivity.getActivityId(),
@@ -293,30 +281,30 @@
                         consumerPort);
                 acg.getConnectorMap().put(connectorId, newActivityCluster);
 
-                /**
+                /*
                  * increasing the port number for the producer and consumer
                  */
                 superActivityProducerPort.put(producerSuperActivity, ++producerSAPort);
                 superActivityConsumerPort.put(consumerSuperActivity, ++consumerSAPort);
             }
-        }
+        });
 
-        /**
+        /*
          * Set up the roots of the new activity cluster
          */
-        for (Entry<ActivityId, SuperActivity> entry : superActivities.entrySet()) {
-            List<IConnectorDescriptor> connIds = newActivityCluster.getActivityOutputMap().get(entry.getKey());
+        superActivities.forEach((key, value) -> {
+            List<IConnectorDescriptor> connIds = newActivityCluster.getActivityOutputMap().get(key);
             if (connIds == null || connIds.isEmpty()) {
-                newActivityCluster.addRoot(entry.getValue());
+                newActivityCluster.addRoot(value);
             }
-        }
+        });
 
-        /**
+        /*
          * set up the blocked2Blocker mapping, which will be updated in the rewriteInterActivityCluster call
          */
         newActivityCluster.getBlocked2BlockerMap().putAll(ac.getBlocked2BlockerMap());
 
-        /**
+        /*
          * replace the old activity cluster with the new activity cluster
          */
         acg.getActivityClusterMap().put(ac.getId(), newActivityCluster);
diff --git a/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/rewriter/runtime/SuperActivity.java b/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/rewriter/runtime/SuperActivity.java
index 476a744..ddcfd78 100644
--- a/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/rewriter/runtime/SuperActivity.java
+++ b/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/rewriter/runtime/SuperActivity.java
@@ -59,17 +59,17 @@
             throws HyracksDataException {
         final Map<ActivityId, IActivity> startActivities = new HashMap<>();
         Map<ActivityId, IActivity> activities = getActivityMap();
-        for (Entry<ActivityId, IActivity> entry : activities.entrySet()) {
-            /**
+        activities.forEach((key, value) -> {
+            /*
              * extract start activities
              */
-            List<IConnectorDescriptor> conns = getActivityInputMap().get(entry.getKey());
+            List<IConnectorDescriptor> conns = getActivityInputMap().get(key);
             if (conns == null || conns.isEmpty()) {
-                startActivities.put(entry.getKey(), entry.getValue());
+                startActivities.put(key, value);
             }
-        }
+        });
 
-        /**
+        /*
          * wrap a RecordDescriptorProvider for the super activity
          */
         IRecordDescriptorProvider wrappedRecDescProvider = new IRecordDescriptorProvider() {
@@ -77,7 +77,7 @@
             @Override
             public RecordDescriptor getInputRecordDescriptor(ActivityId aid, int inputIndex) {
                 if (startActivities.get(aid) != null) {
-                    /**
+                    /*
                      * if the activity is a start (input boundary) activity
                      */
                     int superActivityInputChannel = SuperActivity.this.getClusterInputIndex(Pair.of(aid, inputIndex));
@@ -86,14 +86,14 @@
                     }
                 }
                 if (SuperActivity.this.getActivityMap().get(aid) != null) {
-                    /**
+                    /*
                      * if the activity is an internal activity of the super activity
                      */
                     IConnectorDescriptor conn = getActivityInputMap().get(aid).get(inputIndex);
                     return getConnectorRecordDescriptorMap().get(conn.getConnectorId());
                 }
 
-                /**
+                /*
                  * the following is for the case where the activity is in other SuperActivities
                  */
                 ActivityClusterGraph acg = SuperActivity.this.getActivityClusterGraph();
@@ -121,7 +121,7 @@
 
             @Override
             public RecordDescriptor getOutputRecordDescriptor(ActivityId aid, int outputIndex) {
-                /**
+                /*
                  * if the activity is an output-boundary activity
                  */
                 int superActivityOutputChannel = SuperActivity.this.getClusterOutputIndex(Pair.of(aid, outputIndex));
@@ -130,14 +130,14 @@
                 }
 
                 if (SuperActivity.this.getActivityMap().get(aid) != null) {
-                    /**
+                    /*
                      * if the activity is an internal activity of the super activity
                      */
                     IConnectorDescriptor conn = getActivityOutputMap().get(aid).get(outputIndex);
                     return getConnectorRecordDescriptorMap().get(conn.getConnectorId());
                 }
 
-                /**
+                /*
                  * the following is for the case where the activity is in other SuperActivities
                  */
                 ActivityClusterGraph acg = SuperActivity.this.getActivityClusterGraph();
diff --git a/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/util/ErrorMessageUtil.java b/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/util/ErrorMessageUtil.java
index 285e932..e9491f3 100644
--- a/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/util/ErrorMessageUtil.java
+++ b/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/util/ErrorMessageUtil.java
@@ -56,9 +56,9 @@
         Properties prop = new Properties();
         Map<Integer, String> errorMessageMap = new HashMap<>();
         prop.load(resourceStream);
-        for (Map.Entry<Object, Object> entry : prop.entrySet()) {
-            String key = (String) entry.getKey();
-            String msg = (String) entry.getValue();
+        prop.forEach((key1, value) -> {
+            String key = (String) key1;
+            String msg = (String) value;
             if (key.contains(COMMA)) {
                 String[] codes = key.split(COMMA);
                 for (String code : codes) {
@@ -67,7 +67,7 @@
             } else {
                 errorMessageMap.put(Integer.parseInt(key), msg);
             }
-        }
+        });
         return errorMessageMap;
     }
 
diff --git a/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/util/ExecutionTimeProfiler.java b/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/util/ExecutionTimeProfiler.java
index 66f7f10..e5eec11 100644
--- a/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/util/ExecutionTimeProfiler.java
+++ b/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/util/ExecutionTimeProfiler.java
@@ -22,7 +22,6 @@
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
-import java.util.Map;
 
 public class ExecutionTimeProfiler {
 
@@ -67,9 +66,7 @@
         try {
             synchronized (lock1) {
                 sb.append("\n\n");
-                for (Map.Entry<String, String> entry : spentTimePerJobMap.get(jobSignature).entrySet()) {
-                    sb.append(entry.getValue());
-                }
+                spentTimePerJobMap.get(jobSignature).forEach((key, value) -> sb.append(value));
                 fos.write(sb.toString().getBytes());
                 fos.flush();
                 spentTimePerJobMap.get(jobSignature).clear();
diff --git a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/ClusterControllerService.java b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/ClusterControllerService.java
index a3fbb70..7b99df2 100644
--- a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/ClusterControllerService.java
+++ b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/ClusterControllerService.java
@@ -260,9 +260,9 @@
     }
 
     private void connectNCs() {
-        getNCServices().entrySet().forEach(ncService -> {
+        getNCServices().forEach((key, value) -> {
             final TriggerNCWork triggerWork = new TriggerNCWork(ClusterControllerService.this,
-                    ncService.getValue().getLeft(), ncService.getValue().getRight(), ncService.getKey());
+                    value.getLeft(), value.getRight(), key);
             executor.submit(triggerWork);
         });
         serviceCtx.addClusterLifecycleListener(new IClusterLifecycleListener() {
@@ -289,10 +289,9 @@
 
     private void terminateNCServices() throws Exception {
         List<ShutdownNCServiceWork> shutdownNCServiceWorks = new ArrayList<>();
-        getNCServices().entrySet().forEach(ncService -> {
-            if (ncService.getValue().getRight() != NCConfig.NCSERVICE_PORT_DISABLED) {
-                ShutdownNCServiceWork shutdownWork = new ShutdownNCServiceWork(ncService.getValue().getLeft(),
-                        ncService.getValue().getRight(), ncService.getKey());
+        getNCServices().forEach((key, value) -> {
+            if (value.getRight() != NCConfig.NCSERVICE_PORT_DISABLED) {
+                ShutdownNCServiceWork shutdownWork = new ShutdownNCServiceWork(value.getLeft(), value.getRight(), key);
                 workQueue.schedule(shutdownWork);
                 shutdownNCServiceWorks.add(shutdownWork);
             }
diff --git a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/cluster/NodeManager.java b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/cluster/NodeManager.java
index a380967..3cd6235 100644
--- a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/cluster/NodeManager.java
+++ b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/cluster/NodeManager.java
@@ -135,11 +135,9 @@
     @Override
     public Map<String, NodeControllerInfo> getNodeControllerInfoMap() {
         Map<String, NodeControllerInfo> result = new LinkedHashMap<>();
-        for (Map.Entry<String, NodeControllerState> e : nodeRegistry.entrySet()) {
-            NodeControllerState ncState = e.getValue();
-            result.put(e.getKey(), new NodeControllerInfo(e.getKey(), NodeStatus.ALIVE, ncState.getDataPort(),
-                    ncState.getDatasetPort(), ncState.getMessagingPort(), ncState.getCapacity().getCores()));
-        }
+        nodeRegistry.forEach(
+                (key, ncState) -> result.put(key, new NodeControllerInfo(key, NodeStatus.ALIVE, ncState.getDataPort(),
+                        ncState.getDatasetPort(), ncState.getMessagingPort(), ncState.getCapacity().getCores())));
         return result;
     }
 
diff --git a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/executor/ActivityClusterPlanner.java b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/executor/ActivityClusterPlanner.java
index 57b8c50..04166a4 100644
--- a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/executor/ActivityClusterPlanner.java
+++ b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/executor/ActivityClusterPlanner.java
@@ -242,15 +242,15 @@
 
         JobRun jobRun = executor.getJobRun();
         Map<ConnectorDescriptorId, IConnectorPolicy> connectorPolicies = jobRun.getConnectorPolicyMap();
-        for (Map.Entry<TaskId, List<Pair<TaskId, ConnectorDescriptorId>>> e : taskConnectivity.entrySet()) {
-            Set<TaskId> cluster = taskClusterMap.get(e.getKey());
-            for (Pair<TaskId, ConnectorDescriptorId> p : e.getValue()) {
+        taskConnectivity.forEach((key, value) -> {
+            Set<TaskId> cluster = taskClusterMap.get(key);
+            for (Pair<TaskId, ConnectorDescriptorId> p : value) {
                 IConnectorPolicy cPolicy = connectorPolicies.get(p.getRight());
                 if (cPolicy.requiresProducerConsumerCoscheduling()) {
                     cluster.add(p.getLeft());
                 }
             }
-        }
+        });
 
         /*
          * We compute the transitive closure of this (producer-consumer) relation to find the largest set of
diff --git a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/executor/JobExecutor.java b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/executor/JobExecutor.java
index a3078b6..8a69a6f 100644
--- a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/executor/JobExecutor.java
+++ b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/executor/JobExecutor.java
@@ -65,8 +65,8 @@
 import org.apache.hyracks.control.cc.work.JobCleanupWork;
 import org.apache.hyracks.control.common.job.PartitionState;
 import org.apache.hyracks.control.common.job.TaskAttemptDescriptor;
-import org.apache.hyracks.control.common.work.NoOpCallback;
 import org.apache.hyracks.control.common.work.IResultCallback;
+import org.apache.hyracks.control.common.work.NoOpCallback;
 
 public class JobExecutor {
     private static final Logger LOGGER = Logger.getLogger(JobExecutor.class.getName());
@@ -379,14 +379,13 @@
         tcAttempt.initializePendingTaskCounter();
         tcAttempts.add(tcAttempt);
 
-        /**
+        /*
          * Improvement for reducing master/slave message communications, for each TaskAttemptDescriptor,
          * we set the NetworkAddress[][] partitionLocations, in which each row is for an incoming connector descriptor
          * and each column is for an input channel of the connector.
          */
         INodeManager nodeManager = ccs.getNodeManager();
-        for (Map.Entry<String, List<TaskAttemptDescriptor>> e : taskAttemptMap.entrySet()) {
-            List<TaskAttemptDescriptor> tads = e.getValue();
+        taskAttemptMap.forEach((key, tads) -> {
             for (TaskAttemptDescriptor tad : tads) {
                 TaskAttemptId taid = tad.getTaskAttemptId();
                 int attempt = taid.getAttempt();
@@ -401,7 +400,7 @@
                 for (int i = 0; i < inPartitionCounts.length; ++i) {
                     ConnectorDescriptorId cdId = inConnectors.get(i).getConnectorId();
                     IConnectorPolicy policy = jobRun.getConnectorPolicyMap().get(cdId);
-                    /**
+                    /*
                      * carry sender location information into a task
                      * when it is not the case that it is an re-attempt and the send-side
                      * is materialized blocking.
@@ -419,7 +418,7 @@
                 }
                 tad.setInputPartitionLocations(partitionLocations);
             }
-        }
+        });
 
         tcAttempt.setStatus(TaskClusterAttempt.TaskClusterStatus.RUNNING);
         tcAttempt.setStartTime(System.currentTimeMillis());
@@ -560,12 +559,11 @@
         final JobId jobId = jobRun.getJobId();
         LOGGER.info("Abort map for job: " + jobId + ": " + abortTaskAttemptMap);
         INodeManager nodeManager = ccs.getNodeManager();
-        for (Map.Entry<String, List<TaskAttemptId>> entry : abortTaskAttemptMap.entrySet()) {
-            final NodeControllerState node = nodeManager.getNodeControllerState(entry.getKey());
-            final List<TaskAttemptId> abortTaskAttempts = entry.getValue();
+        abortTaskAttemptMap.forEach((key, abortTaskAttempts) -> {
+            final NodeControllerState node = nodeManager.getNodeControllerState(key);
             if (node != null) {
                 if (LOGGER.isLoggable(Level.INFO)) {
-                    LOGGER.info("Aborting: " + abortTaskAttempts + " at " + entry.getKey());
+                    LOGGER.info("Aborting: " + abortTaskAttempts + " at " + key);
                 }
                 try {
                     node.getNodeController().abortTasks(jobId, abortTaskAttempts);
@@ -573,7 +571,7 @@
                     LOGGER.log(Level.SEVERE, e.getMessage(), e);
                 }
             }
-        }
+        });
         inProgressTaskClusters.remove(tcAttempt.getTaskCluster());
         TaskCluster tc = tcAttempt.getTaskCluster();
         PartitionMatchMaker pmm = jobRun.getPartitionMatchMaker();
diff --git a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/job/JobRun.java b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/job/JobRun.java
index 95a6d9b..ef0bca2 100644
--- a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/job/JobRun.java
+++ b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/job/JobRun.java
@@ -284,10 +284,9 @@
                 ObjectNode planJSON = om.createObjectNode();
 
                 ArrayNode acTasks = om.createArrayNode();
-                for (Map.Entry<ActivityId, ActivityPlan> e : acp.getActivityPlanMap().entrySet()) {
-                    ActivityPlan acPlan = e.getValue();
+                acp.getActivityPlanMap().forEach((key, acPlan) -> {
                     ObjectNode entry = om.createObjectNode();
-                    entry.put("activity-id", e.getKey().toString());
+                    entry.put("activity-id", key.toString());
 
                     ActivityPartitionDetails apd = acPlan.getActivityPartitionDetails();
                     entry.put("partition-count", apd.getPartitionCount());
@@ -319,21 +318,21 @@
                         ArrayNode dependentTasksJSON = om.createArrayNode();
                         for (TaskId dependent : t.getDependents()) {
                             dependentTasksJSON.add(dependent.toString());
-                        task.set("dependents", dependentTasksJSON);
+                            task.set("dependents", dependentTasksJSON);
 
-                        ArrayNode dependencyTasksJSON = om.createArrayNode();
-                        for (TaskId dependency : t.getDependencies()) {
-                            dependencyTasksJSON.add(dependency.toString());
+                            ArrayNode dependencyTasksJSON = om.createArrayNode();
+                            for (TaskId dependency : t.getDependencies()) {
+                                dependencyTasksJSON.add(dependency.toString());
+                            }
+                            task.set("dependencies", dependencyTasksJSON);
+
+                            tasks.add(task);
                         }
-                        task.set("dependencies", dependencyTasksJSON);
+                        entry.set("tasks", tasks);
 
-                        tasks.add(task);
+                        acTasks.add(entry);
                     }
-                    entry.set("tasks", tasks);
-
-                    acTasks.add(entry);
-                    }
-                }
+                });
                 planJSON.set("activities", acTasks);
 
                 ArrayNode tClusters = om.createArrayNode();
diff --git a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/web/StateDumpRESTAPIFunction.java b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/web/StateDumpRESTAPIFunction.java
index ee22768..3c26f84 100644
--- a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/web/StateDumpRESTAPIFunction.java
+++ b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-cc/src/main/java/org/apache/hyracks/control/cc/web/StateDumpRESTAPIFunction.java
@@ -18,16 +18,14 @@
  */
 package org.apache.hyracks.control.cc.web;
 
-import java.util.Map;
-
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.node.ObjectNode;
-
 import org.apache.hyracks.control.cc.ClusterControllerService;
 import org.apache.hyracks.control.cc.web.util.IJSONOutputFunction;
 import org.apache.hyracks.control.cc.work.GatherStateDumpsWork;
 import org.apache.hyracks.control.cc.work.GatherStateDumpsWork.StateDumpRun;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+
 public class StateDumpRESTAPIFunction implements IJSONOutputFunction {
     private final ClusterControllerService ccs;
 
@@ -44,9 +42,7 @@
 
         ObjectMapper om = new ObjectMapper();
         ObjectNode result = om.createObjectNode();
-        for (Map.Entry<String, String> e : sdr.getStateDump().entrySet()) {
-            result.put(e.getKey(), e.getValue());
-        }
+        sdr.getStateDump().forEach(result::put);
         return result;
     }
 
diff --git a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/config/ConfigManager.java b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/config/ConfigManager.java
index d13b5e6..67738ba 100644
--- a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/config/ConfigManager.java
+++ b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/config/ConfigManager.java
@@ -344,20 +344,20 @@
 
     private void applyDefaults() {
         LOGGER.fine("applying defaults");
-        for (Map.Entry<Section, Map<String, IOption>> entry : sectionMap.entrySet()) {
-            if (entry.getKey() == Section.NC) {
-                entry.getValue().values().forEach(option -> getNodeNames()
+        sectionMap.forEach((key, value) -> {
+            if (key == Section.NC) {
+                value.values().forEach(option -> getNodeNames()
                         .forEach(node -> getOrDefault(getNodeEffectiveMap(node), option, node)));
                 for (Map.Entry<String, Map<IOption, Object>> nodeMap : nodeSpecificMap.entrySet()) {
-                    entry.getValue().values()
+                    value.values()
                             .forEach(option -> getOrDefault(
                                     new CompositeMap<>(nodeMap.getValue(), definedMap, new NoOpMapMutator()), option,
                                     nodeMap.getKey()));
                 }
             } else {
-                entry.getValue().values().forEach(option -> getOrDefault(configurationMap, option, null));
+                value.values().forEach(option -> getOrDefault(configurationMap, option, null));
             }
-        }
+        });
     }
 
     private Object getOrDefault(Map<IOption, Object> map, IOption option, String nodeId) {
@@ -450,15 +450,13 @@
 
     public Ini toIni(boolean includeDefaults) {
         Ini ini = new Ini();
-        for (Map.Entry<IOption, Object> entry : (includeDefaults ? configurationMap : definedMap).entrySet()) {
-            if (entry.getValue() != null) {
-                final IOption option = entry.getKey();
-                ini.add(option.section().sectionName(), option.ini(), option.type().serializeToIni(entry.getValue()));
+        (includeDefaults ? configurationMap : definedMap).forEach((option, value) -> {
+            if (value != null) {
+                ini.add(option.section().sectionName(), option.ini(), option.type().serializeToIni(value));
             }
-        }
-        for (Map.Entry<String, Map<IOption, Object>> nodeMapEntry : nodeSpecificMap.entrySet()) {
-            String section = Section.NC.sectionName() + "/" + nodeMapEntry.getKey();
-            final Map<IOption, Object> nodeValueMap = nodeMapEntry.getValue();
+        });
+        nodeSpecificMap.forEach((key, nodeValueMap) -> {
+            String section = Section.NC.sectionName() + "/" + key;
             synchronized (nodeValueMap) {
                 for (Map.Entry<IOption, Object> entry : nodeValueMap.entrySet()) {
                     if (entry.getValue() != null) {
@@ -467,7 +465,7 @@
                     }
                 }
             }
-        }
+        });
         return ini;
     }
 
diff --git a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/job/profiling/om/AbstractProfile.java b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/job/profiling/om/AbstractProfile.java
index d1d33a5..90dfc8c 100644
--- a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/job/profiling/om/AbstractProfile.java
+++ b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/job/profiling/om/AbstractProfile.java
@@ -26,19 +26,19 @@
 import java.util.Map;
 import java.util.Map.Entry;
 
+import org.apache.hyracks.api.io.IWritable;
+
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.node.ArrayNode;
 import com.fasterxml.jackson.databind.node.ObjectNode;
 
-import org.apache.hyracks.api.io.IWritable;
-
 public abstract class AbstractProfile implements IWritable, Serializable {
     private static final long serialVersionUID = 1L;
 
     protected Map<String, Long> counters;
 
     public AbstractProfile() {
-        counters = new HashMap<String, Long>();
+        counters = new HashMap<>();
     }
 
     public Map<String, Long> getCounters() {
@@ -50,12 +50,12 @@
     protected void populateCounters(ObjectNode jo) {
         ObjectMapper om = new ObjectMapper();
         ArrayNode countersObj = om.createArrayNode();
-        for (Map.Entry<String, Long> e : counters.entrySet()) {
+        counters.forEach((key, value) -> {
             ObjectNode jpe = om.createObjectNode();
-            jpe.put("name", e.getKey());
-            jpe.put("value", e.getValue());
+            jpe.put("name", key);
+            jpe.put("value", value);
             countersObj.add(jpe);
-        }
+        });
         jo.set("counters", countersObj);
     }
 
@@ -75,7 +75,7 @@
     @Override
     public void readFields(DataInput input) throws IOException {
         int size = input.readInt();
-        counters = new HashMap<String, Long>();
+        counters = new HashMap<>();
         for (int i = 0; i < size; i++) {
             String key = input.readUTF();
             long value = input.readLong();
diff --git a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/job/profiling/om/JobProfile.java b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/job/profiling/om/JobProfile.java
index 79a5538..64d074b 100644
--- a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/job/profiling/om/JobProfile.java
+++ b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/job/profiling/om/JobProfile.java
@@ -25,10 +25,11 @@
 import java.util.Map;
 import java.util.Map.Entry;
 
+import org.apache.hyracks.api.job.JobId;
+
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.node.ArrayNode;
 import com.fasterxml.jackson.databind.node.ObjectNode;
-import org.apache.hyracks.api.job.JobId;
 
 public class JobProfile extends AbstractProfile {
     private static final long serialVersionUID = 1L;
@@ -49,7 +50,7 @@
 
     public JobProfile(JobId jobId) {
         this.jobId = jobId;
-        jobletProfiles = new HashMap<String, JobletProfile>();
+        jobletProfiles = new HashMap<>();
     }
 
     public JobId getJobId() {
@@ -91,7 +92,7 @@
     public void readFields(DataInput input) throws IOException {
         jobId = JobId.create(input);
         int size = input.readInt();
-        jobletProfiles = new HashMap<String, JobletProfile>();
+        jobletProfiles = new HashMap<>();
         for (int i = 0; i < size; i++) {
             String key = input.readUTF();
             JobletProfile value = JobletProfile.create(input);
diff --git a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/job/profiling/om/JobletProfile.java b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/job/profiling/om/JobletProfile.java
index c3792df..5bdb1b5 100644
--- a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/job/profiling/om/JobletProfile.java
+++ b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-common/src/main/java/org/apache/hyracks/control/common/job/profiling/om/JobletProfile.java
@@ -25,11 +25,11 @@
 import java.util.Map;
 import java.util.Map.Entry;
 
+import org.apache.hyracks.api.dataflow.TaskAttemptId;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.node.ArrayNode;
 import com.fasterxml.jackson.databind.node.ObjectNode;
-import org.apache.hyracks.api.dataflow.TaskAttemptId;
 
 public class JobletProfile extends AbstractProfile {
     private static final long serialVersionUID = 1L;
@@ -50,7 +50,7 @@
 
     public JobletProfile(String nodeId) {
         this.nodeId = nodeId;
-        taskProfiles = new HashMap<TaskAttemptId, TaskProfile>();
+        taskProfiles = new HashMap<>();
     }
 
     public String getNodeId() {
@@ -67,7 +67,7 @@
         ObjectMapper om = new ObjectMapper();
         ObjectNode json = om.createObjectNode();
 
-        json.put("node-id", nodeId.toString());
+        json.put("node-id", nodeId);
         populateCounters(json);
         ArrayNode tasks = om.createArrayNode();
         for (TaskProfile p : taskProfiles.values()) {
@@ -94,7 +94,7 @@
         super.readFields(input);
         nodeId = input.readUTF();
         int size = input.readInt();
-        taskProfiles = new HashMap<TaskAttemptId, TaskProfile>();
+        taskProfiles = new HashMap<>();
         for (int i = 0; i < size; i++) {
             TaskAttemptId key = TaskAttemptId.create(input);
             TaskProfile value = TaskProfile.create(input);
diff --git a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-nc/src/main/java/org/apache/hyracks/control/nc/Joblet.java b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-nc/src/main/java/org/apache/hyracks/control/nc/Joblet.java
index 6dc9619..66a5e0f 100644
--- a/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-nc/src/main/java/org/apache/hyracks/control/nc/Joblet.java
+++ b/hyracks-fullstack/hyracks/hyracks-control/hyracks-control-nc/src/main/java/org/apache/hyracks/control/nc/Joblet.java
@@ -186,9 +186,7 @@
 
     public void dumpProfile(JobletProfile jProfile) {
         Map<String, Long> counters = jProfile.getCounters();
-        for (Map.Entry<String, Counter> e : counterMap.entrySet()) {
-            counters.put(e.getKey(), e.getValue().get());
-        }
+        counterMap.forEach((key, value) -> counters.put(key, value.get()));
         for (Task task : taskMap.values()) {
             TaskProfile taskProfile = new TaskProfile(task.getTaskAttemptId(),
                     new Hashtable<>(task.getPartitionSendProfile()), new StatsCollector());
diff --git a/hyracks-fullstack/hyracks/hyracks-dataflow-std/src/test/java/org/apache/hyracks/dataflow/std/buffermanager/AbstractTupleMemoryManagerTest.java b/hyracks-fullstack/hyracks/hyracks-dataflow-std/src/test/java/org/apache/hyracks/dataflow/std/buffermanager/AbstractTupleMemoryManagerTest.java
index c58a2fa..11148a2 100644
--- a/hyracks-fullstack/hyracks/hyracks-dataflow-std/src/test/java/org/apache/hyracks/dataflow/std/buffermanager/AbstractTupleMemoryManagerTest.java
+++ b/hyracks-fullstack/hyracks/hyracks-dataflow-std/src/test/java/org/apache/hyracks/dataflow/std/buffermanager/AbstractTupleMemoryManagerTest.java
@@ -35,9 +35,9 @@
 import org.apache.hyracks.dataflow.common.comm.io.FrameTupleAppender;
 import org.apache.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer;
 import org.apache.hyracks.dataflow.common.data.marshalling.UTF8StringSerializerDeserializer;
-import org.apache.hyracks.util.IntSerDeUtils;
 import org.apache.hyracks.dataflow.std.sort.Utility;
 import org.apache.hyracks.dataflow.std.structures.TuplePointer;
+import org.apache.hyracks.util.IntSerDeUtils;
 
 public abstract class AbstractTupleMemoryManagerTest {
     ISerializerDeserializer[] fieldsSerDer = new ISerializerDeserializer[] {
@@ -51,13 +51,13 @@
 
     protected void assertEachTupleInFTAIsInBuffer(Map<Integer, Integer> map, Map<TuplePointer, Integer> mapInserted) {
         ITuplePointerAccessor accessor = getTuplePointerAccessor();
-        for (Map.Entry<TuplePointer, Integer> entry : mapInserted.entrySet()) {
-            accessor.reset(entry.getKey());
-            int dataLength = map.get(entry.getValue());
-            assertEquals((int) entry.getValue(),
+        mapInserted.forEach((key, value) -> {
+            accessor.reset(key);
+            int dataLength = map.get(value);
+            assertEquals((int) value,
                     IntSerDeUtils.getInt(accessor.getBuffer().array(), accessor.getAbsFieldStartOffset(0)));
             assertEquals(dataLength, accessor.getTupleLength());
-        }
+        });
         assertEquals(map.size(), mapInserted.size());
     }
 
diff --git a/hyracks-fullstack/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/org/apache/hyracks/tests/unit/AbstractExternalGroupbyTest.java b/hyracks-fullstack/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/org/apache/hyracks/tests/unit/AbstractExternalGroupbyTest.java
index 521dff1..b0c210f 100644
--- a/hyracks-fullstack/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/org/apache/hyracks/tests/unit/AbstractExternalGroupbyTest.java
+++ b/hyracks-fullstack/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/org/apache/hyracks/tests/unit/AbstractExternalGroupbyTest.java
@@ -130,15 +130,15 @@
 
         @Override
         public void open() throws HyracksDataException {
-            for (Map.Entry<Integer, String> keyValue : keyValueMap.entrySet()) {
-                Result result = answer.get(keyValue.getValue());
+            keyValueMap.forEach((key, value) -> {
+                Result result = answer.get(value);
                 if (result == null) {
-                    answer.put(keyValue.getValue(), new Result(keyValue.getKey()));
+                    answer.put(value, new Result(key));
                 } else {
-                    result.sum += keyValue.getKey();
+                    result.sum += key;
                     result.count++;
                 }
-            }
+            });
         }
 
         @Override
diff --git a/hyracks-fullstack/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/org/apache/hyracks/hdfs/scheduler/RackAwareNcCollectionBuilder.java b/hyracks-fullstack/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/org/apache/hyracks/hdfs/scheduler/RackAwareNcCollectionBuilder.java
index 15d11b0..4937a15 100644
--- a/hyracks-fullstack/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/org/apache/hyracks/hdfs/scheduler/RackAwareNcCollectionBuilder.java
+++ b/hyracks-fullstack/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/org/apache/hyracks/hdfs/scheduler/RackAwareNcCollectionBuilder.java
@@ -20,7 +20,6 @@
 
 import java.net.InetAddress;
 import java.util.ArrayList;
-import java.util.Comparator;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -30,7 +29,6 @@
 
 import org.apache.hadoop.io.IntWritable;
 import org.apache.hadoop.mapred.InputSplit;
-
 import org.apache.hyracks.api.client.NodeControllerInfo;
 import org.apache.hyracks.api.topology.ClusterTopology;
 import org.apache.hyracks.hdfs.api.INcCollection;
@@ -51,41 +49,32 @@
             final int[] workloads, final int slotLimit) {
         try {
             final Map<List<Integer>, List<String>> pathToNCs = new HashMap<List<Integer>, List<String>>();
-            for (int i = 0; i < NCs.length; i++) {
-                List<Integer> path = new ArrayList<Integer>();
+            for (String NC : NCs) {
+                List<Integer> path = new ArrayList<>();
                 String ipAddress = InetAddress.getByAddress(
-                        ncNameToNcInfos.get(NCs[i]).getNetworkAddress().lookupIpAddress()).getHostAddress();
+                        ncNameToNcInfos.get(NC).getNetworkAddress().lookupIpAddress()).getHostAddress();
                 topology.lookupNetworkTerminal(ipAddress, path);
-                if (path.size() <= 0) {
+                if (path.isEmpty()) {
                     // if the hyracks nc is not in the defined cluster
                     path.add(Integer.MIN_VALUE);
-                    LOGGER.info(NCs[i] + "'s IP address is not in the cluster toplogy file!");
+                    LOGGER.info(NC + "'s IP address is not in the cluster toplogy file!");
                 }
-                List<String> ncs = pathToNCs.get(path);
-                if (ncs == null) {
-                    ncs = new ArrayList<String>();
-                    pathToNCs.put(path, ncs);
-                }
-                ncs.add(NCs[i]);
+                List<String> ncs = pathToNCs.computeIfAbsent(path, k -> new ArrayList<>());
+                ncs.add(NC);
             }
 
             final TreeMap<List<Integer>, IntWritable> availableIpsToSlots = new TreeMap<List<Integer>, IntWritable>(
-                    new Comparator<List<Integer>>() {
-
-                        @Override
-                        public int compare(List<Integer> l1, List<Integer> l2) {
-                            int commonLength = Math.min(l1.size(), l2.size());
-                            for (int i = 0; i < commonLength; i++) {
-                                Integer value1 = l1.get(i);
-                                Integer value2 = l2.get(i);
-                                int cmp = value1 > value2 ? 1 : (value1 < value2 ? -1 : 0);
-                                if (cmp != 0) {
-                                    return cmp;
-                                }
+                    (l1, l2) -> {
+                        int commonLength = Math.min(l1.size(), l2.size());
+                        for (int i = 0; i < commonLength; i++) {
+                            int value1 = l1.get(i);
+                            int value2 = l2.get(i);
+                            int cmp = Integer.compare(value1, value2);
+                            if (cmp != 0) {
+                                return cmp;
                             }
-                            return l1.size() > l2.size() ? 1 : (l1.size() < l2.size() ? -1 : 0);
                         }
-
+                        return Integer.compare(l1.size(), l2.size());
                     });
             for (int i = 0; i < workloads.length; i++) {
                 if (workloads[i] < slotLimit) {
@@ -93,7 +82,7 @@
                     String ipAddress = InetAddress.getByAddress(
                             ncNameToNcInfos.get(NCs[i]).getNetworkAddress().lookupIpAddress()).getHostAddress();
                     topology.lookupNetworkTerminal(ipAddress, path);
-                    if (path.size() <= 0) {
+                    if (path.isEmpty()) {
                         // if the hyracks nc is not in the defined cluster
                         path.add(Integer.MIN_VALUE);
                     }
@@ -115,41 +104,38 @@
                         int minDistance = Integer.MAX_VALUE;
                         List<Integer> currentCandidatePath = null;
                         if (locs == null || locs.length > 0) {
-                            for (int j = 0; j < locs.length; j++) {
-                                /**
+                            for (String loc : locs) {
+                                /*
                                  * get all the IP addresses from the name
                                  */
-                                InetAddress[] allIps = InetAddress.getAllByName(locs[j]);
+                                InetAddress[] allIps = InetAddress.getAllByName(loc);
                                 boolean inTopology = false;
                                 for (InetAddress ip : allIps) {
-                                    List<Integer> splitPath = new ArrayList<Integer>();
+                                    List<Integer> splitPath = new ArrayList<>();
                                     boolean inCluster = topology.lookupNetworkTerminal(ip.getHostAddress(), splitPath);
                                     if (!inCluster) {
                                         continue;
                                     }
                                     inTopology = true;
-                                    /**
+                                    /*
                                      * if the node controller exists
                                      */
                                     List<Integer> candidatePath = availableIpsToSlots.floorKey(splitPath);
                                     if (candidatePath == null) {
                                         candidatePath = availableIpsToSlots.ceilingKey(splitPath);
                                     }
-                                    if (candidatePath != null) {
-                                        if (availableIpsToSlots.get(candidatePath).get() > 0) {
-                                            int distance = distance(splitPath, candidatePath);
-                                            if (minDistance > distance) {
-                                                minDistance = distance;
-                                                currentCandidatePath = candidatePath;
-                                            }
+                                    if (candidatePath != null && availableIpsToSlots.get(candidatePath).get() > 0) {
+                                        int distance = distance(splitPath, candidatePath);
+                                        if (minDistance > distance) {
+                                            minDistance = distance;
+                                            currentCandidatePath = candidatePath;
                                         }
-
                                     }
                                 }
 
                                 if (!inTopology) {
-                                    LOGGER.info(locs[j] + "'s IP address is not in the cluster toplogy file!");
-                                    /**
+                                    LOGGER.info(loc + "'s IP address is not in the cluster toplogy file!");
+                                    /*
                                      * if the machine is not in the toplogy file
                                      */
                                     List<Integer> candidatePath = null;
@@ -159,11 +145,9 @@
                                             break;
                                         }
                                     }
-                                    /** the split path is empty */
-                                    if (candidatePath != null) {
-                                        if (availableIpsToSlots.get(candidatePath).get() > 0) {
-                                            currentCandidatePath = candidatePath;
-                                        }
+                                    /* the split path is empty */
+                                    if (candidatePath != null && availableIpsToSlots.get(candidatePath).get() > 0) {
+                                        currentCandidatePath = candidatePath;
                                     }
                                 }
                             }
@@ -176,8 +160,8 @@
                             }
                         }
 
-                        if (currentCandidatePath != null && currentCandidatePath.size() > 0) {
-                            /**
+                        if (currentCandidatePath != null && !currentCandidatePath.isEmpty()) {
+                            /*
                              * Update the entry of the selected IP
                              */
                             IntWritable availableSlot = availableIpsToSlots.get(currentCandidatePath);
@@ -185,7 +169,7 @@
                             if (availableSlot.get() == 0) {
                                 availableIpsToSlots.remove(currentCandidatePath);
                             }
-                            /**
+                            /*
                              * Update the entry of the selected NC
                              */
                             List<String> candidateNcs = pathToNCs.get(currentCandidatePath);
@@ -196,7 +180,7 @@
                                 }
                             }
                         }
-                        /** not scheduled */
+                        /* not scheduled */
                         return null;
                     } catch (Exception e) {
                         throw new IllegalStateException(e);
diff --git a/hyracks-fullstack/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/org/apache/hyracks/hdfs/scheduler/Scheduler.java b/hyracks-fullstack/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/org/apache/hyracks/hdfs/scheduler/Scheduler.java
index 2d1c87a..f9b68bc 100644
--- a/hyracks-fullstack/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/org/apache/hyracks/hdfs/scheduler/Scheduler.java
+++ b/hyracks-fullstack/hyracks/hyracks-hdfs/hyracks-hdfs-core/src/main/java/org/apache/hyracks/hdfs/scheduler/Scheduler.java
@@ -379,23 +379,19 @@
             ncNameToIndex.clear();
             int i = 0;
 
-            /**
+            /*
              * build the IP address to NC map
              */
             for (Map.Entry<String, NodeControllerInfo> entry : ncNameToNcInfos.entrySet()) {
                 String ipAddr = InetAddress.getByAddress(entry.getValue().getNetworkAddress().lookupIpAddress())
                         .getHostAddress();
-                List<String> matchedNCs = ipToNcMapping.get(ipAddr);
-                if (matchedNCs == null) {
-                    matchedNCs = new ArrayList<String>();
-                    ipToNcMapping.put(ipAddr, matchedNCs);
-                }
+                List<String> matchedNCs = ipToNcMapping.computeIfAbsent(ipAddr, k -> new ArrayList<>());
                 matchedNCs.add(entry.getKey());
                 NCs[i] = entry.getKey();
                 i++;
             }
 
-            /**
+            /*
              * set up the NC name to index mapping
              */
             for (i = 0; i < NCs.length; i++) {
diff --git a/hyracks-fullstack/hyracks/hyracks-maven-plugins/license-automation-plugin/src/main/java/org/apache/hyracks/maven/license/LicenseMojo.java b/hyracks-fullstack/hyracks/hyracks-maven-plugins/license-automation-plugin/src/main/java/org/apache/hyracks/maven/license/LicenseMojo.java
index 75c5bed..6d8f9cf 100644
--- a/hyracks-fullstack/hyracks/hyracks-maven-plugins/license-automation-plugin/src/main/java/org/apache/hyracks/maven/license/LicenseMojo.java
+++ b/hyracks-fullstack/hyracks/hyracks-maven-plugins/license-automation-plugin/src/main/java/org/apache/hyracks/maven/license/LicenseMojo.java
@@ -123,8 +123,7 @@
 
     protected void addDependenciesToLicenseMap() throws ProjectBuildingException {
         Map<MavenProject, List<Pair<String, String>>> dependencyLicenseMap = gatherDependencies();
-        for (Map.Entry<MavenProject, List<Pair<String, String>>> dep : dependencyLicenseMap.entrySet()) {
-            final MavenProject depProject = dep.getKey();
+        dependencyLicenseMap.forEach((depProject, value) -> {
             Set<String> locations = dependencySets.isEmpty() ? Collections.singleton(location)
                     : getIncludedLocation(depProject.getArtifact());
             if (isExcluded(depProject.getArtifact())) {
@@ -133,10 +132,10 @@
                 getLog().debug("skipping " + depProject + " [not included in dependency sets]");
             } else {
                 for (String depLocation : locations) {
-                    addDependencyToLicenseMap(depProject, dep.getValue(), depLocation);
+                    addDependencyToLicenseMap(depProject, value, depLocation);
                 }
             }
-        }
+        });
     }
 
     private int getLicenseMetric(String url) {
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-common/src/main/java/org/apache/hyracks/storage/common/buffercache/BufferCache.java b/hyracks-fullstack/hyracks/hyracks-storage-common/src/main/java/org/apache/hyracks/storage/common/buffercache/BufferCache.java
index 6304a9a..fcea8e0 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-common/src/main/java/org/apache/hyracks/storage/common/buffercache/BufferCache.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-common/src/main/java/org/apache/hyracks/storage/common/buffercache/BufferCache.java
@@ -801,19 +801,19 @@
         }
 
         synchronized (fileInfoMap) {
-            for (Map.Entry<Integer, BufferedFileHandle> entry : fileInfoMap.entrySet()) {
+            fileInfoMap.forEach((key, value) -> {
                 try {
-                    boolean fileHasBeenDeleted = entry.getValue().fileHasBeenDeleted();
-                    sweepAndFlush(entry.getKey(), !fileHasBeenDeleted);
+                    boolean fileHasBeenDeleted = value.fileHasBeenDeleted();
+                    sweepAndFlush(key, !fileHasBeenDeleted);
                     if (!fileHasBeenDeleted) {
-                        ioManager.close(entry.getValue().getFileHandle());
+                        ioManager.close(value.getFileHandle());
                     }
                 } catch (HyracksDataException e) {
                     if (LOGGER.isLoggable(Level.WARNING)) {
-                        LOGGER.log(Level.WARNING, "Error flushing file id: " + entry.getKey(), e);
+                        LOGGER.log(Level.WARNING, "Error flushing file id: " + key, e);
                     }
                 }
-            }
+            });
             fileInfoMap.clear();
         }
     }