diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/NCQueryServiceServlet.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/NCQueryServiceServlet.java
index 0b0f262..d6ebdad 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/NCQueryServiceServlet.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/NCQueryServiceServlet.java
@@ -36,7 +36,6 @@
 import org.apache.asterix.common.api.IRequestReference;
 import org.apache.asterix.common.config.GlobalConfig;
 import org.apache.asterix.common.exceptions.ErrorCode;
-import org.apache.asterix.common.exceptions.ExceptionUtils;
 import org.apache.asterix.common.exceptions.RuntimeDataException;
 import org.apache.asterix.common.messaging.api.INCMessageBroker;
 import org.apache.asterix.common.messaging.api.MessageFuture;
@@ -46,6 +45,7 @@
 import org.apache.asterix.translator.SessionOutput;
 import org.apache.hyracks.api.application.INCServiceContext;
 import org.apache.hyracks.api.exceptions.Warning;
+import org.apache.hyracks.api.util.ExceptionUtils;
 import org.apache.hyracks.http.api.IChannelClosedHandler;
 import org.apache.hyracks.http.api.IServletRequest;
 import org.apache.hyracks.http.server.HttpServer;
diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/active/ActiveEntityEventsListener.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/active/ActiveEntityEventsListener.java
index e18e50c..0242ecd 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/active/ActiveEntityEventsListener.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/active/ActiveEntityEventsListener.java
@@ -434,6 +434,10 @@
         }
     }
 
+    protected synchronized void doRecover(MetadataProvider metadataProvider) throws HyracksDataException {
+        doStart(metadataProvider);
+    }
+
     private void cancelJob(Throwable th) {
         cancelJobSafely(metadataProvider, th);
         final WaitForStateSubscriber cancelSubscriber =
diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/active/RecoveryTask.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/active/RecoveryTask.java
index 968876d..3bc1c28 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/active/RecoveryTask.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/active/RecoveryTask.java
@@ -125,7 +125,7 @@
                     try {
                         if (!cancelRecovery && listener.getState() == ActivityState.TEMPORARILY_FAILED) {
                             listener.setState(ActivityState.RECOVERING);
-                            listener.doStart(metadataProvider);
+                            listener.doRecover(metadataProvider);
                         }
                         LOGGER.log(level, "Recovery completed successfully");
                         return null;
@@ -141,7 +141,7 @@
                 releaseRecoveryLocks(metadataProvider);
             }
         } while (policy.retry(failure));
-        // Recovery task is essntially over now either through failure or through cancellation(stop)
+        // Recovery task is essentially over now either through failure or through cancellation(stop)
         synchronized (listener) {
             listener.notifyAll();
             if (listener.getState() != ActivityState.TEMPORARILY_FAILED
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 3c5bb98..1d1466c 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
@@ -78,7 +78,6 @@
 import org.apache.asterix.common.exceptions.AsterixException;
 import org.apache.asterix.common.exceptions.CompilationException;
 import org.apache.asterix.common.exceptions.ErrorCode;
-import org.apache.asterix.common.exceptions.ExceptionUtils;
 import org.apache.asterix.common.exceptions.MetadataException;
 import org.apache.asterix.common.exceptions.RuntimeDataException;
 import org.apache.asterix.common.exceptions.WarningCollector;
@@ -2023,7 +2022,7 @@
             validateDatasetState(metadataProvider, ds, sourceLoc);
 
             ds.drop(metadataProvider, mdTxnCtx, jobsToExecute, bActiveTxn, progress, hcc, dropCorrespondingNodeGroup,
-                    sourceLoc, Collections.emptySet(), requestParameters.isForceDropDataset());
+                    sourceLoc, EnumSet.of(DropOption.IF_EXISTS), requestParameters.isForceDropDataset());
 
             MetadataManager.INSTANCE.commitTransaction(mdTxnCtx.getValue());
             return true;
@@ -2039,6 +2038,10 @@
                 try {
                     if (ds != null) {
                         jobsToExecute.clear();
+                        // start another txn for the compensating operations
+                        mdTxnCtx.setValue(MetadataManager.INSTANCE.beginTransaction());
+                        bActiveTxn.setValue(true);
+                        metadataProvider.setMetadataTxnContext(mdTxnCtx.getValue());
                         ds.drop(metadataProvider, mdTxnCtx, jobsToExecute, bActiveTxn, progress, hcc,
                                 dropCorrespondingNodeGroup, sourceLoc, EnumSet.of(DropOption.IF_EXISTS),
                                 requestParameters.isForceDropDataset());
@@ -3979,7 +3982,7 @@
                 printer.print(jobId);
             }
         } catch (Exception e) {
-            if (ExceptionUtils.getRootCause(e) instanceof InterruptedException) {
+            if (org.apache.hyracks.api.util.ExceptionUtils.getRootCause(e) instanceof InterruptedException) {
                 Thread.currentThread().interrupt();
                 throw new RuntimeDataException(ErrorCode.REQUEST_CANCELLED, clientRequest.getId());
             }
diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/utils/RebalanceUtil.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/utils/RebalanceUtil.java
index 429cda9..ccb73b6 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/utils/RebalanceUtil.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/utils/RebalanceUtil.java
@@ -34,7 +34,6 @@
 import org.apache.asterix.app.active.ActiveNotificationHandler;
 import org.apache.asterix.common.api.IMetadataLockManager;
 import org.apache.asterix.common.dataflow.ICcApplicationContext;
-import org.apache.asterix.common.exceptions.ExceptionUtils;
 import org.apache.asterix.common.metadata.DataverseName;
 import org.apache.asterix.common.transactions.TxnId;
 import org.apache.asterix.common.utils.JobUtils;
@@ -182,7 +181,7 @@
                 work.run();
                 done = true;
             } catch (Exception e) {
-                Throwable rootCause = ExceptionUtils.getRootCause(e);
+                Throwable rootCause = org.apache.hyracks.api.util.ExceptionUtils.getRootCause(e);
                 if (rootCause instanceof java.lang.InterruptedException) {
                     interruptedException = (InterruptedException) rootCause;
                     // clear the interrupted state from the thread
diff --git a/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/common/CancellationTestExecutor.java b/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/common/CancellationTestExecutor.java
index d4f92fb..db7ca7d 100644
--- a/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/common/CancellationTestExecutor.java
+++ b/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/common/CancellationTestExecutor.java
@@ -33,7 +33,6 @@
 import java.util.concurrent.Future;
 import java.util.function.Predicate;
 
-import org.apache.asterix.common.exceptions.ExceptionUtils;
 import org.apache.asterix.common.utils.Servlets;
 import org.apache.asterix.test.runtime.SqlppExecutionWithCancellationTest;
 import org.apache.asterix.testframework.context.TestCaseContext;
@@ -43,6 +42,7 @@
 import org.apache.http.HttpResponse;
 import org.apache.http.client.methods.HttpUriRequest;
 import org.apache.http.client.methods.RequestBuilder;
+import org.apache.hyracks.api.util.ExceptionUtils;
 import org.junit.Assert;
 
 public class CancellationTestExecutor extends TestExecutor {
diff --git a/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/common/RebalanceCancellationTestExecutor.java b/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/common/RebalanceCancellationTestExecutor.java
index 3318459..d35bfb7 100644
--- a/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/common/RebalanceCancellationTestExecutor.java
+++ b/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/common/RebalanceCancellationTestExecutor.java
@@ -29,7 +29,6 @@
 import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
 
-import org.apache.asterix.common.exceptions.ExceptionUtils;
 import org.apache.asterix.common.utils.Servlets;
 import org.apache.asterix.testframework.context.TestCaseContext;
 import org.apache.asterix.testframework.xml.ComparisonEnum;
@@ -38,6 +37,7 @@
 import org.apache.http.HttpResponse;
 import org.apache.http.client.methods.HttpUriRequest;
 import org.apache.http.client.methods.RequestBuilder;
+import org.apache.hyracks.api.util.ExceptionUtils;
 import org.apache.logging.log4j.Level;
 import org.junit.Assert;
 
diff --git a/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/runtime/SqlppExecutionWithCancellationTest.java b/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/runtime/SqlppExecutionWithCancellationTest.java
index c5ca66a..eae9d09 100644
--- a/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/runtime/SqlppExecutionWithCancellationTest.java
+++ b/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/runtime/SqlppExecutionWithCancellationTest.java
@@ -20,9 +20,9 @@
 
 import java.util.Collection;
 
-import org.apache.asterix.common.exceptions.ExceptionUtils;
 import org.apache.asterix.test.common.CancellationTestExecutor;
 import org.apache.asterix.testframework.context.TestCaseContext;
+import org.apache.hyracks.api.util.ExceptionUtils;
 import org.junit.AfterClass;
 import org.junit.Assert;
 import org.junit.BeforeClass;
diff --git a/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/txn/LogManagerTest.java b/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/txn/LogManagerTest.java
index 685d983..fb08fe3 100644
--- a/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/txn/LogManagerTest.java
+++ b/asterixdb/asterix-app/src/test/java/org/apache/asterix/test/txn/LogManagerTest.java
@@ -31,7 +31,6 @@
 import org.apache.asterix.common.config.TransactionProperties;
 import org.apache.asterix.common.dataflow.DatasetLocalResource;
 import org.apache.asterix.common.exceptions.ACIDException;
-import org.apache.asterix.common.exceptions.ExceptionUtils;
 import org.apache.asterix.common.transactions.DatasetId;
 import org.apache.asterix.common.transactions.ILockManager;
 import org.apache.asterix.common.transactions.ILogManager;
@@ -113,7 +112,7 @@
                     logManager.log(logRecord);
                 }
             } catch (ACIDException e) {
-                Throwable rootCause = ExceptionUtils.getRootCause(e);
+                Throwable rootCause = org.apache.hyracks.api.util.ExceptionUtils.getRootCause(e);
                 if (rootCause instanceof java.lang.InterruptedException) {
                     interrupted.set(true);
                 }
diff --git a/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/dataflow/NoOpFrameOperationCallbackFactory.java b/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/dataflow/NoOpFrameOperationCallbackFactory.java
index 1d7ad2d..915f3b3 100644
--- a/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/dataflow/NoOpFrameOperationCallbackFactory.java
+++ b/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/dataflow/NoOpFrameOperationCallbackFactory.java
@@ -55,5 +55,10 @@
         public void fail(Throwable th) {
             // No Op
         }
+
+        @Override
+        public void open() throws HyracksDataException {
+            // No Op
+        }
     }
 }
diff --git a/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/exceptions/ExceptionUtils.java b/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/exceptions/ExceptionUtils.java
deleted file mode 100644
index f73848f..0000000
--- a/asterixdb/asterix-common/src/main/java/org/apache/asterix/common/exceptions/ExceptionUtils.java
+++ /dev/null
@@ -1,86 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *   http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-package org.apache.asterix.common.exceptions;
-
-import java.util.function.Predicate;
-
-import org.apache.hyracks.api.exceptions.IFormattedException;
-
-public class ExceptionUtils {
-    public static final String INCORRECT_PARAMETER = "Incorrect parameter.\n";
-    public static final String PARAMETER_NAME = "Parameter name: ";
-    public static final String EXPECTED_VALUE = "Expected value: ";
-    public static final String PASSED_VALUE = "Passed value: ";
-
-    private ExceptionUtils() {
-    }
-
-    public static String incorrectParameterMessage(String parameterName, String expectedValue, String passedValue) {
-        return INCORRECT_PARAMETER + PARAMETER_NAME + parameterName + System.lineSeparator() + EXPECTED_VALUE
-                + expectedValue + System.lineSeparator() + PASSED_VALUE + passedValue;
-    }
-
-    // Gets the error message for the root cause of a given Throwable instance.
-    public static String getErrorMessage(Throwable th) {
-        Throwable cause = getRootCause(th);
-        return cause.getMessage();
-    }
-
-    // Finds the root cause of a given Throwable instance.
-    public static Throwable getRootCause(Throwable e) {
-        Throwable current = e;
-        Throwable cause = e.getCause();
-        while (cause != null && cause != current) {
-            current = cause;
-            cause = current.getCause();
-        }
-        return current;
-    }
-
-    /**
-     * Determines whether supplied exception contains a matching cause in its hierarchy, or is itself a match
-     */
-    public static boolean matchingCause(Throwable e, Predicate<Throwable> test) {
-        Throwable current = e;
-        Throwable cause = e.getCause();
-        while (cause != null && cause != current) {
-            if (test.test(cause)) {
-                return true;
-            }
-            Throwable nextCause = current.getCause();
-            current = cause;
-            cause = nextCause;
-        }
-        return test.test(e);
-    }
-
-    /**
-     * Unwraps enclosed exceptions until a non-product exception is found, otherwise returns the root production
-     * exception
-     */
-    public static Throwable unwrap(Throwable e) {
-        Throwable current = e;
-        Throwable cause = e.getCause();
-        while (cause != null && cause != current && current instanceof IFormattedException) {
-            current = cause;
-            cause = current.getCause();
-        }
-        return current;
-    }
-}
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/stream/LocalFSInputStream.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/stream/LocalFSInputStream.java
index f9eade5..ad762bf 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/stream/LocalFSInputStream.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/stream/LocalFSInputStream.java
@@ -26,7 +26,6 @@
 import java.io.FileInputStream;
 import java.io.IOException;
 
-import org.apache.asterix.common.exceptions.ExceptionUtils;
 import org.apache.asterix.external.dataflow.AbstractFeedDataFlowController;
 import org.apache.asterix.external.util.FeedLogManager;
 import org.apache.asterix.external.util.FileSystemWatcher;
@@ -129,7 +128,7 @@
         if (in == null) {
             return false;
         }
-        Throwable root = ExceptionUtils.getRootCause(th);
+        Throwable root = org.apache.hyracks.api.util.ExceptionUtils.getRootCause(th);
         if (root instanceof HyracksDataException) {
             HyracksDataException r = (HyracksDataException) root;
             boolean advance = false;
diff --git a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/declared/MetadataProvider.java b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/declared/MetadataProvider.java
index 281e59c..1721975 100644
--- a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/declared/MetadataProvider.java
+++ b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/declared/MetadataProvider.java
@@ -235,6 +235,7 @@
         blockingOperatorDisabled = true;
     }
 
+    @Override
     public boolean isBlockingOperatorDisabled() {
         return blockingOperatorDisabled;
     }
diff --git a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/utils/MetadataConstants.java b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/utils/MetadataConstants.java
index f4bea1d..b52cddd 100644
--- a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/utils/MetadataConstants.java
+++ b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/utils/MetadataConstants.java
@@ -32,7 +32,7 @@
     public static final int METADATA_OBJECT_NAME_LENGTH_LIMIT_UTF8 = 251;
     public static final int DATAVERSE_NAME_TOTAL_LENGTH_LIMIT_UTF8 = METADATA_OBJECT_NAME_LENGTH_LIMIT_UTF8 * 4;
     public static final Pattern METADATA_OBJECT_NAME_INVALID_CHARS =
-            Pattern.compile(SystemUtils.IS_OS_WINDOWS ? "[\u0000-\u001F\u007F\"*/:<>\\\\|+,.;=\\[\\]\n]" : "[\u0000/]");
+            Pattern.compile(SystemUtils.IS_OS_WINDOWS ? "[\u0000-\u001F\u007F\"*/:<>\\\\|+,;=\\[\\]\n]" : "[\u0000/]");
 
     // Name of the dataverse the metadata lives in.
     public static final DataverseName METADATA_DATAVERSE_NAME = DataverseName.createBuiltinDataverseName("Metadata");
diff --git a/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/operators/LSMPrimaryInsertOperatorNodePushable.java b/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/operators/LSMPrimaryInsertOperatorNodePushable.java
index a886161..eadb614 100644
--- a/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/operators/LSMPrimaryInsertOperatorNodePushable.java
+++ b/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/operators/LSMPrimaryInsertOperatorNodePushable.java
@@ -191,6 +191,7 @@
                 PrimaryIndexLogMarkerCallback callback = new PrimaryIndexLogMarkerCallback((AbstractLSMIndex) index);
                 TaskUtil.put(ILogMarkerCallback.KEY_MARKER_CALLBACK, callback, ctx);
             }
+            frameOpCallback.open();
             writer.open();
             keySearchCmp =
                     BTreeUtils.getSearchMultiComparator(((ITreeIndex) index).getComparatorFactories(), frameTuple);
diff --git a/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/operators/LSMPrimaryUpsertOperatorNodePushable.java b/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/operators/LSMPrimaryUpsertOperatorNodePushable.java
index f5bddc5..8e0de5f 100644
--- a/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/operators/LSMPrimaryUpsertOperatorNodePushable.java
+++ b/asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/operators/LSMPrimaryUpsertOperatorNodePushable.java
@@ -291,7 +291,13 @@
                 public void fail(Throwable th) {
                     callback.fail(th);
                 }
+
+                @Override
+                public void open() throws HyracksDataException {
+                    callback.open();
+                }
             };
+            frameOpCallback.open();
         } catch (Throwable e) { // NOSONAR: Re-thrown
             throw HyracksDataException.create(e);
         }
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 508eb76..29dedf7 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
@@ -230,20 +230,21 @@
     @Override
     public synchronized void delete(String relativePath) throws HyracksDataException {
         FileReference resourceFile = getLocalResourceFileByName(ioManager, relativePath);
-        if (resourceFile.getFile().exists()) {
-            if (isReplicationEnabled) {
-                createReplicationJob(ReplicationOperation.DELETE, resourceFile);
+        try {
+            if (resourceFile.getFile().exists()) {
+                if (isReplicationEnabled) {
+                    createReplicationJob(ReplicationOperation.DELETE, resourceFile);
+                }
+                final LocalResource localResource = readLocalResource(resourceFile.getFile());
+                IoUtil.delete(resourceFile);
+                // delete all checkpoints
+                indexCheckpointManagerProvider.get(DatasetResourceReference.of(localResource)).delete();
+            } else {
+                throw HyracksDataException.create(org.apache.hyracks.api.exceptions.ErrorCode.RESOURCE_DOES_NOT_EXIST,
+                        relativePath);
             }
-            final LocalResource localResource = readLocalResource(resourceFile.getFile());
-            // Invalidate before deleting the file just in case file deletion throws some exception.
-            // Since it's just a cache invalidation, it should not affect correctness.
+        } finally {
             resourceCache.invalidate(relativePath);
-            IoUtil.delete(resourceFile);
-            // delete all checkpoints
-            indexCheckpointManagerProvider.get(DatasetResourceReference.of(localResource)).delete();
-        } else {
-            throw HyracksDataException.create(org.apache.hyracks.api.exceptions.ErrorCode.RESOURCE_DOES_NOT_EXIST,
-                    relativePath);
         }
     }
 
diff --git a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/metadata/IMetadataProvider.java b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/metadata/IMetadataProvider.java
index e505960..8540d0b 100644
--- a/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/metadata/IMetadataProvider.java
+++ b/hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/metadata/IMetadataProvider.java
@@ -229,4 +229,6 @@
 
     public Map<String, Object> getConfig();
 
+    public boolean isBlockingOperatorDisabled();
+
 }
diff --git a/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/IntroJoinInsideSubplanRule.java b/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/IntroJoinInsideSubplanRule.java
index 3175367..f2532b4 100644
--- a/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/IntroJoinInsideSubplanRule.java
+++ b/hyracks-fullstack/algebricks/algebricks-rewriter/src/main/java/org/apache/hyracks/algebricks/rewriter/rules/IntroJoinInsideSubplanRule.java
@@ -44,6 +44,9 @@
     @Override
     public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context)
             throws AlgebricksException {
+        if (context.getMetadataProvider().isBlockingOperatorDisabled()) {
+            return false;
+        }
         AbstractLogicalOperator op0 = (AbstractLogicalOperator) opRef.getValue();
         if (op0.getOperatorTag() != LogicalOperatorTag.SUBPLAN) {
             return false;
diff --git a/hyracks-fullstack/algebricks/algebricks-runtime/src/main/java/org/apache/hyracks/algebricks/runtime/operators/meta/SubplanRuntimeFactory.java b/hyracks-fullstack/algebricks/algebricks-runtime/src/main/java/org/apache/hyracks/algebricks/runtime/operators/meta/SubplanRuntimeFactory.java
index 48d7fd2..349e50f 100644
--- a/hyracks-fullstack/algebricks/algebricks-runtime/src/main/java/org/apache/hyracks/algebricks/runtime/operators/meta/SubplanRuntimeFactory.java
+++ b/hyracks-fullstack/algebricks/algebricks-runtime/src/main/java/org/apache/hyracks/algebricks/runtime/operators/meta/SubplanRuntimeFactory.java
@@ -174,7 +174,7 @@
 
         @Override
         public void flush() throws HyracksDataException {
-            writer.flush();
+            appender.flush(writer);
         }
 
         /**
diff --git a/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/util/ExceptionUtils.java b/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/util/ExceptionUtils.java
index d748ed8..7c304b9 100644
--- a/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/util/ExceptionUtils.java
+++ b/hyracks-fullstack/hyracks/hyracks-api/src/main/java/org/apache/hyracks/api/util/ExceptionUtils.java
@@ -23,9 +23,11 @@
 import java.util.List;
 import java.util.Map;
 import java.util.function.Function;
+import java.util.function.Predicate;
 
 import org.apache.hyracks.api.exceptions.ErrorCode;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
+import org.apache.hyracks.api.exceptions.IFormattedException;
 import org.apache.hyracks.util.ThrowingFunction;
 
 import com.google.common.util.concurrent.UncheckedExecutionException;
@@ -158,4 +160,41 @@
             throw HyracksDataException.create(e.getCause());
         }
     }
+
+    // Gets the error message for the root cause of a given Throwable instance.
+    public static String getErrorMessage(Throwable th) {
+        Throwable cause = getRootCause(th);
+        return cause.getMessage();
+    }
+
+    /**
+     * Determines whether supplied exception contains a matching cause in its hierarchy, or is itself a match
+     */
+    public static boolean matchingCause(Throwable e, Predicate<Throwable> test) {
+        Throwable current = e;
+        Throwable cause = e.getCause();
+        while (cause != null && cause != current) {
+            if (test.test(cause)) {
+                return true;
+            }
+            Throwable nextCause = current.getCause();
+            current = cause;
+            cause = nextCause;
+        }
+        return test.test(e);
+    }
+
+    /**
+     * Unwraps enclosed exceptions until a non-product exception is found, otherwise returns the root production
+     * exception
+     */
+    public static Throwable unwrap(Throwable e) {
+        Throwable current = e;
+        Throwable cause = e.getCause();
+        while (cause != current && cause instanceof IFormattedException) {
+            current = cause;
+            cause = current.getCause();
+        }
+        return current;
+    }
 }
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-common/src/main/java/org/apache/hyracks/storage/am/common/dataflow/IndexDropOperatorNodePushable.java b/hyracks-fullstack/hyracks/hyracks-storage-am-common/src/main/java/org/apache/hyracks/storage/am/common/dataflow/IndexDropOperatorNodePushable.java
index e48db2b..3b6669e 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-common/src/main/java/org/apache/hyracks/storage/am/common/dataflow/IndexDropOperatorNodePushable.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-common/src/main/java/org/apache/hyracks/storage/am/common/dataflow/IndexDropOperatorNodePushable.java
@@ -21,6 +21,7 @@
 
 import static org.apache.hyracks.api.exceptions.ErrorCode.CANNOT_DROP_IN_USE_INDEX;
 import static org.apache.hyracks.api.exceptions.ErrorCode.INDEX_DOES_NOT_EXIST;
+import static org.apache.hyracks.api.exceptions.ErrorCode.RESOURCE_DOES_NOT_EXIST;
 import static org.apache.hyracks.storage.am.common.dataflow.IndexDropOperatorDescriptor.DropOption.IF_EXISTS;
 import static org.apache.hyracks.storage.am.common.dataflow.IndexDropOperatorDescriptor.DropOption.WAIT_ON_IN_USE;
 
@@ -96,7 +97,7 @@
     }
 
     private boolean isIgnorable(HyracksDataException e) {
-        return e.matches(INDEX_DOES_NOT_EXIST) && options.contains(IF_EXISTS);
+        return (e.matches(INDEX_DOES_NOT_EXIST) || e.matches(RESOURCE_DOES_NOT_EXIST)) && options.contains(IF_EXISTS);
     }
 
     private boolean canRetry(HyracksDataException e) throws HyracksDataException {
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/api/IFrameOperationCallback.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/api/IFrameOperationCallback.java
index 78e5862..1f89af2 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/api/IFrameOperationCallback.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/api/IFrameOperationCallback.java
@@ -40,4 +40,9 @@
      * @param th
      */
     void fail(Throwable th);
+
+    /**
+     * Called when the task has opened for initialization.
+     */
+    void open() throws HyracksDataException;
 }