diff --git a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/WordInvertedIndexTest.java b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/WordInvertedIndexTest.java
index 0ecbd15..a63cc07 100644
--- a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/WordInvertedIndexTest.java
+++ b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/WordInvertedIndexTest.java
@@ -60,7 +60,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ConstantMergePolicyProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.FlushControllerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateSchedulerProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.RefCountingOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.RefCountingOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndexSearchModifierFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow.BinaryTokenizerOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow.LSMInvertedIndexBulkLoadOperatorDescriptor;
@@ -93,7 +93,7 @@
     private IIndexDataflowHelperFactory btreeDataflowHelperFactory = new BTreeDataflowHelperFactory();
     private IIndexDataflowHelperFactory invertedIndexDataflowHelperFactory = new LSMInvertedIndexDataflowHelperFactory(
             new FlushControllerProvider(), new ConstantMergePolicyProvider(ImmediateSchedulerProvider.INSTANCE,
-                    MERGE_THRESHOLD), new RefCountingOperationTrackerProvider(), ImmediateSchedulerProvider.INSTANCE);
+                    MERGE_THRESHOLD), RefCountingOperationTrackerFactory.INSTANCE, ImmediateSchedulerProvider.INSTANCE);
 
     private final static SimpleDateFormat simpleDateFormat = new SimpleDateFormat("ddMMyy-hhmmssSS");
     private final static String sep = System.getProperty("file.separator");
diff --git a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/btree/LSMBTreeOperatorTestHelper.java b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/btree/LSMBTreeOperatorTestHelper.java
index 8c019dc..6dd0307 100644
--- a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/btree/LSMBTreeOperatorTestHelper.java
+++ b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/btree/LSMBTreeOperatorTestHelper.java
@@ -20,7 +20,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.btree.dataflow.LSMBTreeDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ConstantMergePolicyProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.FlushControllerProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.RefCountingOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.RefCountingOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateSchedulerProvider;
 import edu.uci.ics.hyracks.tests.am.common.LSMTreeOperatorTestHelper;
 
@@ -34,7 +34,7 @@
 
     public IIndexDataflowHelperFactory createDataFlowHelperFactory() {
         return new LSMBTreeDataflowHelperFactory(new FlushControllerProvider(), new ConstantMergePolicyProvider(
-                ImmediateSchedulerProvider.INSTANCE, MERGE_THRESHOLD), new RefCountingOperationTrackerProvider(),
+                ImmediateSchedulerProvider.INSTANCE, MERGE_THRESHOLD), RefCountingOperationTrackerFactory.INSTANCE,
                 ImmediateSchedulerProvider.INSTANCE);
     }
 
diff --git a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeOperatorTestHelper.java b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeOperatorTestHelper.java
index 5aa7bd2..0ee5c89 100644
--- a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeOperatorTestHelper.java
+++ b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeOperatorTestHelper.java
@@ -23,7 +23,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ConstantMergePolicyProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.FlushControllerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateSchedulerProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.RefCountingOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.RefCountingOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.dataflow.LSMRTreeDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
 import edu.uci.ics.hyracks.tests.am.common.LSMTreeOperatorTestHelper;
@@ -41,7 +41,7 @@
             IBinaryComparatorFactory[] btreeComparatorFactories, ILinearizeComparatorFactory linearizerCmpFactory) {
         return new LSMRTreeDataflowHelperFactory(valueProviderFactories, rtreePolicyType, btreeComparatorFactories,
                 new FlushControllerProvider(), new ConstantMergePolicyProvider(ImmediateSchedulerProvider.INSTANCE,
-                        MERGE_THRESHOLD), new RefCountingOperationTrackerProvider(),
+                        MERGE_THRESHOLD), RefCountingOperationTrackerFactory.INSTANCE,
                 ImmediateSchedulerProvider.INSTANCE, linearizerCmpFactory);
     }
 
diff --git a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesOperatorTestHelper.java b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesOperatorTestHelper.java
index 82a7eb6..86115a4 100644
--- a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesOperatorTestHelper.java
+++ b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesOperatorTestHelper.java
@@ -23,7 +23,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ConstantMergePolicyProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.FlushControllerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateSchedulerProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.RefCountingOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.RefCountingOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.dataflow.LSMRTreeWithAntiMatterTuplesDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
 import edu.uci.ics.hyracks.tests.am.common.LSMTreeOperatorTestHelper;
@@ -42,7 +42,7 @@
         return new LSMRTreeWithAntiMatterTuplesDataflowHelperFactory(valueProviderFactories, rtreePolicyType,
                 btreeComparatorFactories, new FlushControllerProvider(), new ConstantMergePolicyProvider(
                         ImmediateSchedulerProvider.INSTANCE, MERGE_THRESHOLD),
-                new RefCountingOperationTrackerProvider(), ImmediateSchedulerProvider.INSTANCE, linearizerCmpFactory);
+                RefCountingOperationTrackerFactory.INSTANCE, ImmediateSchedulerProvider.INSTANCE, linearizerCmpFactory);
     }
 
 }
diff --git a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeOpContext.java b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeOpContext.java
index 31557cf..2f4131d 100644
--- a/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeOpContext.java
+++ b/hyracks-storage-am-btree/src/main/java/edu/uci/ics/hyracks/storage/am/btree/impls/BTreeOpContext.java
@@ -211,4 +211,9 @@
             tuple.reset(builder.getFieldEndOffsets(), builder.getByteArray());
         }
     }
+
+    @Override
+    public IndexOperation getOperation() {
+        return op;
+    }
 }
diff --git a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IIndexOperationContext.java b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IIndexOperationContext.java
index df76345..c5bf83e 100644
--- a/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IIndexOperationContext.java
+++ b/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IIndexOperationContext.java
@@ -4,6 +4,8 @@
 
 public interface IIndexOperationContext {
     void setOperation(IndexOperation newOp);
+    
+    IndexOperation getOperation();
 
     void reset();
 }
diff --git a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java
index efcf918..794b84b 100644
--- a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java
+++ b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java
@@ -28,7 +28,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelper;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
@@ -38,16 +38,17 @@
 public class LSMBTreeDataflowHelper extends AbstractLSMIndexDataflowHelper {
 
     public LSMBTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler) {
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler) {
         this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES, flushController, mergePolicy,
-                opTracker, ioScheduler);
+                opTrackerFactory, ioScheduler);
     }
 
     public LSMBTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
             int memPageSize, int memNumPages, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
-            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) {
-        super(opDesc, ctx, partition, memPageSize, memNumPages, flushController, mergePolicy, opTracker, ioScheduler);
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler) {
+        super(opDesc, ctx, partition, memPageSize, memNumPages, flushController, mergePolicy, opTrackerFactory,
+                ioScheduler);
     }
 
     @Override
@@ -60,6 +61,6 @@
         return LSMBTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ctx.getIOManager(), file, opDesc
                 .getStorageManager().getBufferCache(ctx), opDesc.getStorageManager().getFileMapProvider(ctx),
                 treeOpDesc.getTreeIndexTypeTraits(), treeOpDesc.getTreeIndexComparatorFactories(), flushController,
-                mergePolicy, opTracker, ioScheduler);
+                mergePolicy, opTrackerFactory, ioScheduler);
     }
 }
diff --git a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java
index 739247e..8a177c0 100644
--- a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java
+++ b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java
@@ -21,7 +21,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushControllerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelperFactory;
 
 public class LSMBTreeDataflowHelperFactory extends AbstractLSMIndexDataflowHelperFactory {
@@ -29,16 +29,16 @@
     private static final long serialVersionUID = 1L;
 
     public LSMBTreeDataflowHelperFactory(ILSMFlushControllerProvider flushControllerProvider,
-            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerProvider,
+            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerFactory opTrackerFactory,
             ILSMIOOperationSchedulerProvider ioSchedulerProvider) {
-        super(flushControllerProvider, mergePolicyProvider, opTrackerProvider, ioSchedulerProvider);
+        super(flushControllerProvider, mergePolicyProvider, opTrackerFactory, ioSchedulerProvider);
     }
 
     @Override
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
         return new LSMBTreeDataflowHelper(opDesc, ctx, partition, flushControllerProvider.getFlushController(ctx),
-                mergePolicyProvider.getMergePolicy(ctx), opTrackerProvider.getOperationTracker(ctx),
+                mergePolicyProvider.getMergePolicy(ctx), opTrackerFactory,
                 ioSchedulerProvider.getIOScheduler(ctx));
     }
 }
diff --git a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
index f26b890..50cd61b 100644
--- a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
+++ b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
@@ -59,6 +59,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexInternal;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BlockingIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMFlushOperation;
@@ -103,8 +104,8 @@
             ITreeIndexFrameFactory deleteLeafFrameFactory, ILSMIndexFileManager fileNameManager,
             TreeIndexFactory<BTree> diskBTreeFactory, TreeIndexFactory<BTree> bulkLoadBTreeFactory,
             IFileMapProvider diskFileMapProvider, int fieldCount, IBinaryComparatorFactory[] cmpFactories,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler) {
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler) {
         memBTree = new BTree(memBufferCache, ((InMemoryBufferCache) memBufferCache).getFileMapProvider(),
                 memFreePageManager, interiorFrameFactory, insertLeafFrameFactory, cmpFactories, fieldCount,
                 new FileReference(new File("membtree")));
@@ -118,6 +119,7 @@
         this.cmpFactories = cmpFactories;
         this.diskBTrees = new LinkedList<Object>();
         this.fileManager = fileNameManager;
+        ILSMOperationTracker opTracker = opTrackerFactory.createOperationTracker(this);
         lsmHarness = new LSMHarness(this, flushController, mergePolicy, opTracker, ioScheduler);
         componentFinalizer = new TreeIndexComponentFinalizer(diskFileMapProvider);
         diskBTrees = new LinkedList<Object>();
@@ -213,8 +215,7 @@
     public void insertUpdateOrDelete(ITupleReference tuple, IIndexOperationContext ictx) throws HyracksDataException,
             IndexException {
         LSMBTreeOpContext ctx = (LSMBTreeOpContext) ictx;
-
-        switch (ctx.getIndexOp()) {
+        switch (ctx.getOperation()) {
             case PHYSICALDELETE:
                 ctx.memBTreeAccessor.delete(tuple);
                 break;
diff --git a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java
index 80190bf..87938f7 100644
--- a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java
+++ b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeOpContext.java
@@ -112,7 +112,7 @@
     public void reset() {
     }
 
-    public IndexOperation getIndexOp() {
+    public IndexOperation getOperation() {
         return op;
     }
 }
\ No newline at end of file
diff --git a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeUtils.java b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeUtils.java
index 664e4c1..9fc7b92 100644
--- a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeUtils.java
+++ b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeUtils.java
@@ -36,7 +36,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BTreeFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.TreeIndexFactory;
@@ -48,7 +48,7 @@
             IInMemoryFreePageManager memFreePageManager, IIOManager ioManager, FileReference file,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
             IBinaryComparatorFactory[] cmpFactories, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
-            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) {
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler) {
         LSMBTreeTupleWriterFactory insertTupleWriterFactory = new LSMBTreeTupleWriterFactory(typeTraits,
                 cmpFactories.length, false);
         LSMBTreeTupleWriterFactory deleteTupleWriterFactory = new LSMBTreeTupleWriterFactory(typeTraits,
@@ -72,7 +72,7 @@
         LSMBTree lsmTree = new LSMBTree(memBufferCache, memFreePageManager, interiorFrameFactory,
                 insertLeafFrameFactory, deleteLeafFrameFactory, fileNameManager, diskBTreeFactory,
                 bulkLoadBTreeFactory, diskFileMapProvider, typeTraits.length, cmpFactories, flushController,
-                mergePolicy, opTracker, ioScheduler);
+                mergePolicy, opTrackerFactory, ioScheduler);
         return lsmTree;
     }
 }
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java
index 965daf8..04354bb 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java
@@ -2,6 +2,7 @@
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor;
+import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
 
 /**
  * This interface exposes methods for tracking and setting the status of operations for the purpose
@@ -17,7 +18,7 @@
      * i.e., before any latches are taken.
      * After this method has been called, the operation is considered 'active'.
      */
-    public void beforeOperation(ILSMIndex index) throws HyracksDataException;
+    public void beforeOperation(IndexOperation op) throws HyracksDataException;
 
     /**
      * An {@link ILSMIndex} will call this method after an operation has left the index,
@@ -25,12 +26,12 @@
      * After this method has been called, the operation is still considered 'active',
      * until the issuer of the operation declares it completed by calling completeOperation().
      */
-    public void afterOperation(ILSMIndex index) throws HyracksDataException;
+    public void afterOperation(IndexOperation op) throws HyracksDataException;
 
     /**
      * This method must be called by whoever is requesting the index operation through an {@link IIndexAccessor}.
      * The use of this method indicates that the operation is no longer 'active'
      * for the purpose of coordinating flushes/merges.
      */
-    public void completeOperation(ILSMIndex index) throws HyracksDataException;
+    public void completeOperation(IndexOperation op) throws HyracksDataException;
 }
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerFactory.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerFactory.java
new file mode 100644
index 0000000..db7ff6c
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerFactory.java
@@ -0,0 +1,7 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.io.Serializable;
+
+public interface ILSMOperationTrackerFactory extends Serializable {
+    public ILSMOperationTracker createOperationTracker(ILSMIndex index);
+}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerProvider.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerProvider.java
deleted file mode 100644
index eeec28f..0000000
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerProvider.java
+++ /dev/null
@@ -1,10 +0,0 @@
-package edu.uci.ics.hyracks.storage.am.lsm.common.api;
-
-import java.io.Serializable;
-
-import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
-
-
-public interface ILSMOperationTrackerProvider extends Serializable {
-    public ILSMOperationTracker getOperationTracker(IHyracksTaskContext ctx);
-}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java
index e85c7ea..70db775 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java
@@ -21,7 +21,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 
 public abstract class AbstractLSMIndexDataflowHelper extends IndexDataflowHelper {
 
@@ -32,26 +32,26 @@
     protected final int memNumPages;
 
     protected final ILSMFlushController flushController;
-    protected final ILSMMergePolicy mergePolicy;
-    protected final ILSMOperationTracker opTracker;
+    protected final ILSMMergePolicy mergePolicy;    
     protected final ILSMIOOperationScheduler ioScheduler;
+    protected final ILSMOperationTrackerFactory opTrackerFactory;
 
     public AbstractLSMIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
             ILSMIOOperationScheduler ioScheduler) {
         this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES, flushController, mergePolicy,
-                opTracker, ioScheduler);
+                opTrackerFactory, ioScheduler);
     }
 
     public AbstractLSMIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
             int memPageSize, int memNumPages, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
-            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) {
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler) {
         super(opDesc, ctx, partition);
         this.memPageSize = memPageSize;
         this.memNumPages = memNumPages;
         this.flushController = flushController;
         this.mergePolicy = mergePolicy;
-        this.opTracker = opTracker;
+        this.opTrackerFactory = opTrackerFactory;
         this.ioScheduler = ioScheduler;
     }
 }
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java
index 27a4d47..de48bff 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java
@@ -19,22 +19,22 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushControllerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 
 public abstract class AbstractLSMIndexDataflowHelperFactory implements IIndexDataflowHelperFactory {
     protected static final long serialVersionUID = 1L;
 
     protected final ILSMFlushControllerProvider flushControllerProvider;
     protected final ILSMMergePolicyProvider mergePolicyProvider;
-    protected final ILSMOperationTrackerProvider opTrackerProvider;
+    protected final ILSMOperationTrackerFactory opTrackerFactory;
     protected final ILSMIOOperationSchedulerProvider ioSchedulerProvider;
 
     public AbstractLSMIndexDataflowHelperFactory(ILSMFlushControllerProvider flushControllerProvider,
-            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerProvider,
+            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerFactory opTrackerFactory,
             ILSMIOOperationSchedulerProvider ioSchedulerProvider) {
         this.flushControllerProvider = flushControllerProvider;
         this.mergePolicyProvider = mergePolicyProvider;
-        this.opTrackerProvider = opTrackerProvider;
+        this.opTrackerFactory = opTrackerFactory;
         this.ioSchedulerProvider = ioSchedulerProvider;
     }
 }
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
index 38159b9..d049476 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
@@ -28,6 +28,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexOperationContext;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchPredicate;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
@@ -82,23 +83,23 @@
         this.ioScheduler = ioScheduler;
     }
 
-    private void threadExit() throws HyracksDataException {
+    private void threadExit(IndexOperation op) throws HyracksDataException {
         if (!lsmIndex.getFlushController().getFlushStatus(lsmIndex) && lsmIndex.getInMemoryFreePageManager().isFull()) {
             lsmIndex.getFlushController().setFlushStatus(lsmIndex, true);
         }
-        opTracker.afterOperation(lsmIndex);
+        opTracker.afterOperation(op);
     }
 
     public void insertUpdateOrDelete(ITupleReference tuple, IIndexOperationContext ctx) throws HyracksDataException,
             IndexException {
-        opTracker.beforeOperation(lsmIndex);
+        opTracker.beforeOperation(ctx.getOperation());
         // It is possible, due to concurrent execution of operations, that an operation will 
         // fail. In such a case, simply retry the operation. Refer to the specific LSMIndex code 
         // to see exactly why an operation might fail.
         try {
             lsmIndex.insertUpdateOrDelete(tuple, ctx);
         } finally {
-            threadExit();
+            threadExit(ctx.getOperation());
         }
     }
 
@@ -129,7 +130,7 @@
         // If the search doesn't include the in-memory component, then we don't have
         // to synchronize with a flush.
         if (includeMemComponent) {
-            opTracker.beforeOperation(lsmIndex);
+            opTracker.beforeOperation(ctx.getOperation());
         }
 
         // Get a snapshot of the current on-disk Trees.
@@ -227,7 +228,7 @@
         // If the in-memory Tree was not included in the search, then we don't
         // need to synchronize with a flush.
         if (includeMemComponent) {
-            threadExit();
+            threadExit(IndexOperation.SEARCH);
         }
         // A merge may be waiting on this searcher to finish searching the on-disk components.
         // Decrement the searcherRefCount so that the merge process is able to cleanup any old
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/RefCountingOperationTrackerFactory.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/RefCountingOperationTrackerFactory.java
new file mode 100644
index 0000000..aa4e551
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/RefCountingOperationTrackerFactory.java
@@ -0,0 +1,21 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+
+public class RefCountingOperationTrackerFactory implements ILSMOperationTrackerFactory {
+
+    private static final long serialVersionUID = 1L;
+    
+    public static RefCountingOperationTrackerFactory INSTANCE = new RefCountingOperationTrackerFactory(); 
+    
+    @Override
+    public ILSMOperationTracker createOperationTracker(ILSMIndex index) {
+        return new ReferenceCountingOperationTracker(index);
+    }
+
+    // Enforce singleton.
+    private RefCountingOperationTrackerFactory() {
+    }
+}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/RefCountingOperationTrackerProvider.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/RefCountingOperationTrackerProvider.java
deleted file mode 100644
index 5963a55..0000000
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/RefCountingOperationTrackerProvider.java
+++ /dev/null
@@ -1,16 +0,0 @@
-package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
-
-import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
-
-public class RefCountingOperationTrackerProvider implements ILSMOperationTrackerProvider {
-
-    private static final long serialVersionUID = 1L;
-
-    @Override
-    public ILSMOperationTracker getOperationTracker(IHyracksTaskContext ctx) {
-        return new ReferenceCountingOperationTracker();
-    }
-
-}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ReferenceCountingOperationTracker.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ReferenceCountingOperationTracker.java
index cbd5aea..4b6349c 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ReferenceCountingOperationTracker.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ReferenceCountingOperationTracker.java
@@ -2,6 +2,7 @@
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
+import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
@@ -10,50 +11,50 @@
 public class ReferenceCountingOperationTracker implements ILSMOperationTracker {
 
     private int threadRefCount = 0;
+    private final ILSMIndex index;
+    private final FlushOperationCallback FLUSHCALLBACK_INSTANCE = new FlushOperationCallback();
 
-    @Override
-    public void beforeOperation(final ILSMIndex index) throws HyracksDataException {
-        synchronized (this) {
-            // flushFlag may be set to true even though the flush has not occurred yet.
-            // If flushFlag is set, then the flush is queued to occur by the last exiting thread.
-            // This operation should wait for that flush to occur before proceeding.
-            if (!index.getFlushController().getFlushStatus(index)) {
-                // Increment the threadRefCount in order to block the possibility of a concurrent flush.
-                // The corresponding threadExit() call is in LSMTreeRangeSearchCursor.close()
-            } else {
-                try {
-                    this.wait();
-                } catch (InterruptedException e) {
-                    throw new HyracksDataException(e);
-                }
-            }
-            threadRefCount++;
-        }
+    public ReferenceCountingOperationTracker(ILSMIndex index) {
+        this.index = index;
     }
 
     @Override
-    public void afterOperation(final ILSMIndex index) throws HyracksDataException {
+    public synchronized void beforeOperation(IndexOperation op) throws HyracksDataException {
+        // Wait for pending flushes to complete.
+        // If flushFlag is set, then the flush is queued to occur by the last exiting thread.
+        // This operation should wait for that flush to occur before proceeding.
+        if (index.getFlushController().getFlushStatus(index)) {
+            try {
+                this.wait();
+            } catch (InterruptedException e) {
+                throw new HyracksDataException(e);
+            }
+        }
+        threadRefCount++;
+    }
+
+    @Override
+    public void afterOperation(IndexOperation op) throws HyracksDataException {
         // The operation is considered inactive, immediately after leaving the index.
-        completeOperation(index);
+        completeOperation(op);
     }
 
     @Override
-    public void completeOperation(final ILSMIndex index) throws HyracksDataException {
-        synchronized (this) {
-            threadRefCount--;
+    public synchronized void completeOperation(IndexOperation op) throws HyracksDataException {
+        threadRefCount--;
 
-            // Flush will only be handled by last exiting thread.
-            if (index.getFlushController().getFlushStatus(index) && threadRefCount == 0) {
-                ILSMIndexAccessor accessor = (ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
-                        NoOpOperationCallback.INSTANCE);
-                index.getIOScheduler().scheduleOperation(accessor.createFlushOperation(new ILSMIOOperationCallback() {
-                    @Override
-                    public void callback() {
-                        ReferenceCountingOperationTracker.this.notifyAll();
-                    }
-                }));
-            }
+        // Flush will only be handled by last exiting thread.
+        if (index.getFlushController().getFlushStatus(index) && threadRefCount == 0) {
+            ILSMIndexAccessor accessor = (ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
+                    NoOpOperationCallback.INSTANCE);
+            index.getIOScheduler().scheduleOperation(accessor.createFlushOperation(FLUSHCALLBACK_INSTANCE));
         }
     }
 
+    private class FlushOperationCallback implements ILSMIOOperationCallback {
+        @Override
+        public void callback() {
+            ReferenceCountingOperationTracker.this.notifyAll();
+        }
+    }
 }
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java
index 6e77533..773c493 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java
@@ -26,7 +26,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelper;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryFreePageManager;
@@ -40,16 +40,17 @@
 public final class LSMInvertedIndexDataflowHelper extends AbstractLSMIndexDataflowHelper {
 
     public LSMInvertedIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler) {
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler) {
         this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES, flushController, mergePolicy,
-                opTracker, ioScheduler);
+                opTrackerFactory, ioScheduler);
     }
 
     public LSMInvertedIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
             int memPageSize, int memNumPages, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
-            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) {
-        super(opDesc, ctx, partition, memPageSize, memNumPages, flushController, mergePolicy, opTracker, ioScheduler);
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler) {
+        super(opDesc, ctx, partition, memPageSize, memNumPages, flushController, mergePolicy, opTrackerFactory,
+                ioScheduler);
     }
 
     @Override
@@ -68,7 +69,7 @@
                     invIndexOpDesc.getInvListsComparatorFactories(), invIndexOpDesc.getTokenTypeTraits(),
                     invIndexOpDesc.getTokenComparatorFactories(), invIndexOpDesc.getTokenizerFactory(),
                     diskBufferCache, ctx.getIOManager(), file.getFile().getPath(), flushController, mergePolicy,
-                    opTracker, ioScheduler);
+                    opTrackerFactory, ioScheduler);
             return invIndex;
         } catch (IndexException e) {
             throw new HyracksDataException(e);
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelperFactory.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelperFactory.java
index db84a89..e3c8d0f 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelperFactory.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelperFactory.java
@@ -21,7 +21,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushControllerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelperFactory;
 
 public class LSMInvertedIndexDataflowHelperFactory extends AbstractLSMIndexDataflowHelperFactory {
@@ -29,7 +29,7 @@
     private static final long serialVersionUID = 1L;
 
     public LSMInvertedIndexDataflowHelperFactory(ILSMFlushControllerProvider flushControllerProvider,
-            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerProvider,
+            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerFactory opTrackerProvider,
             ILSMIOOperationSchedulerProvider ioSchedulerProvider) {
         super(flushControllerProvider, mergePolicyProvider, opTrackerProvider, ioSchedulerProvider);
     }
@@ -37,9 +37,9 @@
     @Override
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
-        return new LSMInvertedIndexDataflowHelper(opDesc, ctx, partition, flushControllerProvider.getFlushController(ctx),
-                mergePolicyProvider.getMergePolicy(ctx), opTrackerProvider.getOperationTracker(ctx),
-                ioSchedulerProvider.getIOScheduler(ctx));
+        return new LSMInvertedIndexDataflowHelper(opDesc, ctx, partition,
+                flushControllerProvider.getFlushController(ctx), mergePolicyProvider.getMergePolicy(ctx),
+                opTrackerFactory, ioSchedulerProvider.getIOScheduler(ctx));
     }
 
 }
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
index 09434f0..2ae5317 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
@@ -59,6 +59,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexInternal;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BTreeFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BlockingIOOperationCallback;
@@ -128,7 +129,7 @@
             ILSMIndexFileManager fileManager, IFileMapProvider diskFileMapProvider, ITypeTraits[] invListTypeTraits,
             IBinaryComparatorFactory[] invListCmpFactories, ITypeTraits[] tokenTypeTraits,
             IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
             ILSMIOOperationScheduler ioScheduler) throws IndexException {
         InMemoryInvertedIndex memInvIndex = InvertedIndexUtils.createInMemoryBTreeInvertedindex(memBufferCache,
                 memFreePageManager, invListTypeTraits, invListCmpFactories, tokenTypeTraits, tokenCmpFactories,
@@ -147,6 +148,7 @@
         this.invListCmpFactories = invListCmpFactories;
         this.tokenTypeTraits = tokenTypeTraits;
         this.tokenCmpFactories = tokenCmpFactories;
+        ILSMOperationTracker opTracker = opTrackerFactory.createOperationTracker(this);
         this.lsmHarness = new LSMHarness(this, flushController, mergePolicy, opTracker, ioScheduler);
         this.componentFinalizer = new LSMInvertedIndexComponentFinalizer(diskFileMapProvider);
         diskComponents = new LinkedList<Object>();
@@ -325,7 +327,7 @@
             IndexException {
         LSMInvertedIndexOpContext ctx = (LSMInvertedIndexOpContext) ictx;
         ctx.modificationCallback.before(tuple);
-        switch (ctx.getIndexOp()) {
+        switch (ctx.getOperation()) {
             case INSERT: {
                 // Insert into the in-memory inverted index.                
                 ctx.memInvIndexAccessor.insert(tuple);
@@ -345,7 +347,7 @@
                 break;
             }
             default: {
-                throw new UnsupportedOperationException("Operation " + ctx.getIndexOp() + " not supported.");
+                throw new UnsupportedOperationException("Operation " + ctx.getOperation() + " not supported.");
             }
         }
     }
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java
index dacc974..0920d86 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexOpContext.java
@@ -82,7 +82,8 @@
         op = newOp;
     }
     
-    public IndexOperation getIndexOp() {
+    @Override
+    public IndexOperation getOperation() {
         return op;
     }
 }
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/InMemoryInvertedIndexOpContext.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/InMemoryInvertedIndexOpContext.java
index 82c095f..4a77e52 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/InMemoryInvertedIndexOpContext.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/InMemoryInvertedIndexOpContext.java
@@ -83,4 +83,9 @@
     public void reset() {
         op = null;
     }
+
+    @Override
+    public IndexOperation getOperation() {
+        return op;
+    }
 }
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/ondisk/OnDiskInvertedIndexOpContext.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/ondisk/OnDiskInvertedIndexOpContext.java
index 1b4ff94c..fd784f3 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/ondisk/OnDiskInvertedIndexOpContext.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/ondisk/OnDiskInvertedIndexOpContext.java
@@ -47,4 +47,9 @@
     public void setOperation(IndexOperation newOp) {
         // Nothing to be done here, only search operation supported.
     }
+
+    @Override
+    public IndexOperation getOperation() {
+        return IndexOperation.SEARCH;
+    }
 }
diff --git a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/InvertedIndexUtils.java b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/InvertedIndexUtils.java
index 2505596..7da9416 100644
--- a/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/InvertedIndexUtils.java
+++ b/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/InvertedIndexUtils.java
@@ -37,7 +37,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BTreeFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedListBuilder;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedListBuilderFactory;
@@ -83,7 +83,7 @@
             ITypeTraits[] tokenTypeTraits, IBinaryComparatorFactory[] tokenCmpFactories,
             IBinaryTokenizerFactory tokenizerFactory, IBufferCache diskBufferCache, IIOManager ioManager,
             String onDiskDir, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
-            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) throws IndexException {
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler) throws IndexException {
 
         TypeAwareTupleWriterFactory tupleWriterFactory = new TypeAwareTupleWriterFactory(invListTypeTraits);
         ITreeIndexFrameFactory leafFrameFactory = BTreeUtils.getLeafFrameFactory(tupleWriterFactory,
@@ -108,7 +108,7 @@
 
         LSMInvertedIndex invIndex = new LSMInvertedIndex(memBufferCache, memFreePageManager, invIndexFactory,
                 deletedKeysBTreeFactory, fileManager, diskFileMapProvider, invListTypeTraits, invListCmpFactories,
-                tokenTypeTraits, tokenCmpFactories, tokenizerFactory, flushController, mergePolicy, opTracker,
+                tokenTypeTraits, tokenCmpFactories, tokenizerFactory, flushController, mergePolicy, opTrackerFactory,
                 ioScheduler);
         return invIndex;
     }
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java
index b62a219..e3369a4 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java
@@ -33,7 +33,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelper;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryFreePageManager;
@@ -52,19 +52,22 @@
     public AbstractLSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
             IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler, ILinearizeComparatorFactory linearizeCmpFactory) {
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            ILinearizeComparatorFactory linearizeCmpFactory) {
         this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES, btreeComparatorFactories,
-                valueProviderFactories, rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler,
+                valueProviderFactories, rtreePolicyType, flushController, mergePolicy, opTrackerFactory, ioScheduler,
                 linearizeCmpFactory);
     }
 
     public AbstractLSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
             int memPageSize, int memNumPages, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler, ILinearizeComparatorFactory linearizeCmpFactory) {
-        super(opDesc, ctx, partition, memPageSize, memNumPages, flushController, mergePolicy, opTracker, ioScheduler);
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            ILinearizeComparatorFactory linearizeCmpFactory) {
+        super(opDesc, ctx, partition, memPageSize, memNumPages, flushController, mergePolicy, opTrackerFactory,
+                ioScheduler);
         this.btreeComparatorFactories = btreeComparatorFactories;
         this.valueProviderFactories = valueProviderFactories;
         this.rtreePolicyType = rtreePolicyType;
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java
index 214aaea..6546dc0 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java
@@ -31,7 +31,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.utils.LSMRTreeUtils;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
@@ -42,19 +42,21 @@
     public LSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
             IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler, ILinearizeComparatorFactory linearizeCmpFactory) {
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            ILinearizeComparatorFactory linearizeCmpFactory) {
         super(opDesc, ctx, partition, btreeComparatorFactories, valueProviderFactories, rtreePolicyType,
-                flushController, mergePolicy, opTracker, ioScheduler, linearizeCmpFactory);
+                flushController, mergePolicy, opTrackerFactory, ioScheduler, linearizeCmpFactory);
     }
 
     public LSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
             int memPageSize, int memNumPages, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler, ILinearizeComparatorFactory linearizeCmpFactory) {
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            ILinearizeComparatorFactory linearizeCmpFactory) {
         super(opDesc, ctx, partition, memPageSize, memNumPages, btreeComparatorFactories, valueProviderFactories,
-                rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler, linearizeCmpFactory);
+                rtreePolicyType, flushController, mergePolicy, opTrackerFactory, ioScheduler, linearizeCmpFactory);
     }
 
     @Override
@@ -67,7 +69,7 @@
         try {
             return LSMRTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ioManager, file, diskBufferCache,
                     diskFileMapProvider, typeTraits, rtreeCmpFactories, btreeCmpFactories, valueProviderFactories,
-                    rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler, linearizeCmpFactory);
+                    rtreePolicyType, flushController, mergePolicy, opTrackerFactory, ioScheduler, linearizeCmpFactory);
         } catch (TreeIndexException e) {
             throw new HyracksDataException(e);
         }
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java
index 1778fe5..5ba724c 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java
@@ -24,7 +24,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushControllerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
 
@@ -40,9 +40,9 @@
     public LSMRTreeDataflowHelperFactory(IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType, IBinaryComparatorFactory[] btreeComparatorFactories,
             ILSMFlushControllerProvider flushControllerProvider, ILSMMergePolicyProvider mergePolicyProvider,
-            ILSMOperationTrackerProvider opTrackerProvider, ILSMIOOperationSchedulerProvider ioSchedulerProvider,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationSchedulerProvider ioSchedulerProvider,
             ILinearizeComparatorFactory linearizeCmpFactory) {
-        super(flushControllerProvider, mergePolicyProvider, opTrackerProvider, ioSchedulerProvider);
+        super(flushControllerProvider, mergePolicyProvider, opTrackerFactory, ioSchedulerProvider);
         this.btreeComparatorFactories = btreeComparatorFactories;
         this.valueProviderFactories = valueProviderFactories;
         this.rtreePolicyType = rtreePolicyType;
@@ -54,7 +54,7 @@
             int partition) {
         return new LSMRTreeDataflowHelper(opDesc, ctx, partition, btreeComparatorFactories, valueProviderFactories,
                 rtreePolicyType, flushControllerProvider.getFlushController(ctx),
-                mergePolicyProvider.getMergePolicy(ctx), opTrackerProvider.getOperationTracker(ctx),
-                ioSchedulerProvider.getIOScheduler(ctx), linearizeCmpFactory);
+                mergePolicyProvider.getMergePolicy(ctx), opTrackerFactory, ioSchedulerProvider.getIOScheduler(ctx),
+                linearizeCmpFactory);
     }
 }
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelper.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelper.java
index d9d505e..be2bddb 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelper.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelper.java
@@ -31,7 +31,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.utils.LSMRTreeUtils;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
@@ -41,19 +41,21 @@
     public LSMRTreeWithAntiMatterTuplesDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler, ILinearizeComparatorFactory linearizeCmpFactory) {
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            ILinearizeComparatorFactory linearizeCmpFactory) {
         super(opDesc, ctx, partition, btreeComparatorFactories, valueProviderFactories, rtreePolicyType,
-                flushController, mergePolicy, opTracker, ioScheduler, linearizeCmpFactory);
+                flushController, mergePolicy, opTrackerFactory, ioScheduler, linearizeCmpFactory);
     }
 
     public LSMRTreeWithAntiMatterTuplesDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition, int memPageSize, int memNumPages, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler, ILinearizeComparatorFactory linearizeCmpFactory) {
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            ILinearizeComparatorFactory linearizeCmpFactory) {
         super(opDesc, ctx, partition, memPageSize, memNumPages, btreeComparatorFactories, valueProviderFactories,
-                rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler, linearizeCmpFactory);
+                rtreePolicyType, flushController, mergePolicy, opTrackerFactory, ioScheduler, linearizeCmpFactory);
     }
 
     @Override
@@ -66,8 +68,8 @@
         try {
             return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(memBufferCache, memFreePageManager, ioManager, file,
                     diskBufferCache, diskFileMapProvider, typeTraits, rtreeCmpFactories, btreeCmpFactories,
-                    valueProviderFactories, rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler,
-                    linearizeCmpFactory);
+                    valueProviderFactories, rtreePolicyType, flushController, mergePolicy, opTrackerFactory,
+                    ioScheduler, linearizeCmpFactory);
         } catch (TreeIndexException e) {
             throw new HyracksDataException(e);
         }
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelperFactory.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelperFactory.java
index 09c3ba2..dddbccc 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelperFactory.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelperFactory.java
@@ -25,7 +25,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushControllerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
 
 public class LSMRTreeWithAntiMatterTuplesDataflowHelperFactory implements IIndexDataflowHelperFactory {
@@ -37,14 +37,14 @@
     private final RTreePolicyType rtreePolicyType;
     private final ILSMFlushControllerProvider flushControllerProvider;
     private final ILSMMergePolicyProvider mergePolicyProvider;
-    private final ILSMOperationTrackerProvider opTrackerProvider;
+    private final ILSMOperationTrackerFactory opTrackerProvider;
     private final ILSMIOOperationSchedulerProvider ioSchedulerProvider;
     private final ILinearizeComparatorFactory linearizeCmpFactory;
 
     public LSMRTreeWithAntiMatterTuplesDataflowHelperFactory(IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType, IBinaryComparatorFactory[] btreeComparatorFactories,
             ILSMFlushControllerProvider flushControllerProvider, ILSMMergePolicyProvider mergePolicyProvider,
-            ILSMOperationTrackerProvider opTrackerProvider, ILSMIOOperationSchedulerProvider ioSchedulerProvider,
+            ILSMOperationTrackerFactory opTrackerProvider, ILSMIOOperationSchedulerProvider ioSchedulerProvider,
             ILinearizeComparatorFactory linearizeCmpFactory) {
         this.btreeComparatorFactories = btreeComparatorFactories;
         this.valueProviderFactories = valueProviderFactories;
@@ -61,7 +61,7 @@
             int partition) {
         return new LSMRTreeWithAntiMatterTuplesDataflowHelper(opDesc, ctx, partition, btreeComparatorFactories,
                 valueProviderFactories, rtreePolicyType, flushControllerProvider.getFlushController(ctx),
-                mergePolicyProvider.getMergePolicy(ctx), opTrackerProvider.getOperationTracker(ctx),
-                ioSchedulerProvider.getIOScheduler(ctx), linearizeCmpFactory);
+                mergePolicyProvider.getMergePolicy(ctx), opTrackerProvider, ioSchedulerProvider.getIOScheduler(ctx),
+                linearizeCmpFactory);
     }
 }
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java
index 3ede232..7711a89 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java
@@ -47,6 +47,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexInternal;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BlockingIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMHarness;
@@ -124,7 +125,7 @@
             IFileMapProvider diskFileMapProvider, ILSMComponentFinalizer componentFinalizer, int fieldCount,
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
             ILinearizeComparatorFactory linearizer, int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
             ILSMIOOperationScheduler ioScheduler) {
         RTree memRTree = new RTree(memBufferCache, ((InMemoryBufferCache) memBufferCache).getFileMapProvider(),
                 memFreePageManager, rtreeInteriorFrameFactory, rtreeLeafFrameFactory, rtreeCmpFactories, fieldCount,
@@ -145,6 +146,7 @@
         this.diskRTreeFactory = diskRTreeFactory;
         this.btreeCmpFactories = btreeCmpFactories;
         this.rtreeCmpFactories = rtreeCmpFactories;
+        ILSMOperationTracker opTracker = opTrackerFactory.createOperationTracker(this);
         this.lsmHarness = new LSMHarness(this, flushController, mergePolicy, opTracker, ioScheduler);
         this.componentFinalizer = componentFinalizer;
         this.linearizer = linearizer;
@@ -275,11 +277,11 @@
     public void insertUpdateOrDelete(ITupleReference tuple, IIndexOperationContext ictx) throws HyracksDataException,
             IndexException {
         LSMRTreeOpContext ctx = (LSMRTreeOpContext) ictx;
-        if (ctx.getIndexOp() == IndexOperation.PHYSICALDELETE) {
+        if (ctx.getOperation() == IndexOperation.PHYSICALDELETE) {
             throw new UnsupportedOperationException("Physical delete not yet supported in LSM R-tree");
         }
 
-        if (ctx.getIndexOp() == IndexOperation.INSERT) {
+        if (ctx.getOperation() == IndexOperation.INSERT) {
             // Before each insert, we must check whether there exist a killer
             // tuple in the memBTree. If we find a killer tuple, we must truly
             // delete the existing tuple from the BTree, and then insert it to
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java
index 8eca83a..00d8823 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java
@@ -50,7 +50,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMTreeIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.TreeIndexFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.impls.LSMRTreeFileManager.LSMRTreeFileNameComponent;
@@ -73,12 +73,13 @@
             TreeIndexFactory<BTree> diskBTreeFactory, IFileMapProvider diskFileMapProvider, int fieldCount,
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
             ILinearizeComparatorFactory linearizer, int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler) {
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler) {
         super(memBufferCache, memFreePageManager, rtreeInteriorFrameFactory, rtreeLeafFrameFactory,
                 btreeInteriorFrameFactory, btreeLeafFrameFactory, fileManager, diskRTreeFactory, diskFileMapProvider,
                 new LSMRTreeComponentFinalizer(diskFileMapProvider), fieldCount, rtreeCmpFactories, btreeCmpFactories,
-                linearizer, comparatorFields, linearizerArray, flushController, mergePolicy, opTracker, ioScheduler);
+                linearizer, comparatorFields, linearizerArray, flushController, mergePolicy, opTrackerFactory,
+                ioScheduler);
         this.diskBTreeFactory = diskBTreeFactory;
     }
 
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java
index 5bfe741..5bafec6 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeOpContext.java
@@ -71,7 +71,8 @@
 
     }
 
-    public IndexOperation getIndexOp() {
+    @Override
+    public IndexOperation getOperation() {
         return op;
     }
 
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java
index 1d66eb4..6bd744e 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java
@@ -51,7 +51,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMFlushOperation;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMMergeOperation;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMTreeIndexAccessor;
@@ -80,11 +80,13 @@
             IFileMapProvider diskFileMapProvider, int fieldCount, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, ILinearizeComparatorFactory linearizer,
             int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, ILSMFlushController flushController,
-            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) {
+            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
+            ILSMIOOperationScheduler ioScheduler) {
         super(memBufferCache, memFreePageManager, rtreeInteriorFrameFactory, rtreeLeafFrameFactory,
                 btreeInteriorFrameFactory, btreeLeafFrameFactory, fileManager, diskRTreeFactory, diskFileMapProvider,
                 new TreeIndexComponentFinalizer(diskFileMapProvider), fieldCount, rtreeCmpFactories, btreeCmpFactories,
-                linearizer, comparatorFields, linearizerArray, flushController, mergePolicy, opTracker, ioScheduler);
+                linearizer, comparatorFields, linearizerArray, flushController, mergePolicy, opTrackerFactory,
+                ioScheduler);
         this.bulkLoadRTreeFactory = bulkLoadRTreeFactory;
         this.bTreeTupleSorter = null;
     }
diff --git a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/utils/LSMRTreeUtils.java b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/utils/LSMRTreeUtils.java
index e85a9e4..c6562d7 100644
--- a/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/utils/LSMRTreeUtils.java
+++ b/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/utils/LSMRTreeUtils.java
@@ -37,7 +37,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BTreeFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.TreeIndexFactory;
@@ -64,7 +64,7 @@
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
             ILSMIOOperationScheduler ioScheduler, ILinearizeComparatorFactory linearizeCmpFactory)
             throws TreeIndexException {
         LSMTypeAwareTupleWriterFactory rtreeTupleWriterFactory = new LSMTypeAwareTupleWriterFactory(typeTraits, false);
@@ -98,7 +98,7 @@
                 rtreeLeafFrameFactory, btreeInteriorFrameFactory, btreeLeafFrameFactory, fileNameManager,
                 diskRTreeFactory, diskBTreeFactory, diskFileMapProvider, typeTraits.length, rtreeCmpFactories,
                 btreeCmpFactories, linearizeCmpFactory, comparatorFields, linearizerArray, flushController,
-                mergePolicy, opTracker, ioScheduler);
+                mergePolicy, opTrackerFactory, ioScheduler);
         return lsmTree;
     }
 
@@ -107,7 +107,7 @@
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushController flushPolicy, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMFlushController flushPolicy, ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
             ILSMIOOperationScheduler ioScheduler, ILinearizeComparatorFactory linearizerCmpFactory)
             throws TreeIndexException {
 
@@ -151,7 +151,7 @@
                 rtreeInteriorFrameFactory, rtreeLeafFrameFactory, btreeInteriorFrameFactory, btreeLeafFrameFactory,
                 fileNameManager, diskRTreeFactory, bulkLoadRTreeFactory, diskFileMapProvider, typeTraits.length,
                 rtreeCmpFactories, btreeCmpFactories, linearizerCmpFactory, comparatorFields, linearizerArray,
-                flushPolicy, mergePolicy, opTracker, ioScheduler);
+                flushPolicy, mergePolicy, opTrackerFactory, ioScheduler);
         return lsmTree;
     }
 
diff --git a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTreeOpContext.java b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTreeOpContext.java
index a9ada89..6ff55bc 100644
--- a/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTreeOpContext.java
+++ b/hyracks-storage-am-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/rtree/impls/RTreeOpContext.java
@@ -101,4 +101,9 @@
         }
         this.op = newOp;
     }
+
+    @Override
+    public IndexOperation getOperation() {
+        return op;
+    }
 }
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeBulkLoadTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeBulkLoadTest.java
index e10d30e..d04fa72 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeBulkLoadTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeBulkLoadTest.java
@@ -54,7 +54,7 @@
         return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFlushController(),
-                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler());
     }
 
     @Override
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeDeleteTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeDeleteTest.java
index c75c2d2..0eb3d36 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeDeleteTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeDeleteTest.java
@@ -54,7 +54,7 @@
         return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFlushController(),
-                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler());
     }
 
     @Override
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java
index 66e24ea..6250197 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java
@@ -37,7 +37,7 @@
         return LSMBTreeUtils.createLSMTree(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), typeTraits, cmpFactories, harness.getFlushController(),
-                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler());
     }
 
     @Before
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeInsertTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeInsertTest.java
index 3eba66c..9a80f57 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeInsertTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeInsertTest.java
@@ -54,7 +54,7 @@
         return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFlushController(),
-                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler());
     }
 
     @Override
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeLifecycleTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeLifecycleTest.java
index 2e8fcaf..0061943 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeLifecycleTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeLifecycleTest.java
@@ -45,7 +45,7 @@
         testCtx = LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, fieldSerdes.length, harness.getFlushController(),
-                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler());
         index = testCtx.getIndex();
     }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java
index 3cd7e42..62dda0d 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java
@@ -53,7 +53,7 @@
         return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFlushController(),
-                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler());
     }
 
     @Override
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeModificationOperationCallbackTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeModificationOperationCallbackTest.java
index 62a1d71..6495fa6 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeModificationOperationCallbackTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeModificationOperationCallbackTest.java
@@ -2,7 +2,6 @@
 
 import org.junit.Test;
 
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.util.SerdeUtils;
 import edu.uci.ics.hyracks.dataflow.common.util.TupleUtils;
 import edu.uci.ics.hyracks.storage.am.btree.AbstractModificationOperationCallbackTest;
@@ -11,10 +10,9 @@
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeUtils;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BlockingIOOperationCallback;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoOpOperationTrackerFactory;
 
 public class LSMBTreeModificationOperationCallbackTest extends AbstractModificationOperationCallbackTest {
     private static final int NUM_TUPLES = 11;
@@ -30,27 +28,11 @@
 
     @Override
     protected void createIndexInstance() throws Exception {
-        ILSMOperationTracker tracker = new ILSMOperationTracker() {
-            @Override
-            public void afterOperation(ILSMIndex index) {
-                // Do nothing
-            }
-
-            @Override
-            public void beforeOperation(ILSMIndex index) {
-                // Do nothing
-            }
-
-            @Override
-            public void completeOperation(ILSMIndex index) throws HyracksDataException {
-                // Do nothing
-            }
-        };
         index = LSMBTreeUtils.createLSMTree(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), SerdeUtils.serdesToTypeTraits(keySerdes),
                 SerdeUtils.serdesToComparatorFactories(keySerdes, keySerdes.length), harness.getFlushController(),
-                harness.getMergePolicy(), tracker, harness.getIOScheduler());
+                harness.getMergePolicy(), NoOpOperationTrackerFactory.INSTANCE, harness.getIOScheduler());
     }
 
     @Override
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMultiBulkLoadTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMultiBulkLoadTest.java
index 96f7778..97a5781 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMultiBulkLoadTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMultiBulkLoadTest.java
@@ -55,7 +55,7 @@
         return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFlushController(),
-                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler());
     }
 
     @Override
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeSearchOperationCallbackTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeSearchOperationCallbackTest.java
index e51c8cc..72ff348 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeSearchOperationCallbackTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeSearchOperationCallbackTest.java
@@ -21,8 +21,7 @@
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeUtils;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoOpOperationTrackerFactory;
 
 public class LSMBTreeSearchOperationCallbackTest extends AbstractSearchOperationCallbackTest {
     private final LSMBTreeTestHarness harness;
@@ -33,27 +32,11 @@
 
     @Override
     protected void createIndexInstance() throws Exception {
-        ILSMOperationTracker tracker = new ILSMOperationTracker() {
-            @Override
-            public void afterOperation(ILSMIndex index) {
-                // Do nothing
-            }
-
-            @Override
-            public void beforeOperation(ILSMIndex index) {
-                // Do nothing
-            }
-
-            @Override
-            public void completeOperation(ILSMIndex index) throws HyracksDataException {
-                // Do nothing
-            }
-        };
         index = LSMBTreeUtils.createLSMTree(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), SerdeUtils.serdesToTypeTraits(keySerdes),
                 SerdeUtils.serdesToComparatorFactories(keySerdes, keySerdes.length), harness.getFlushController(),
-                harness.getMergePolicy(), tracker, harness.getIOScheduler());
+                harness.getMergePolicy(), NoOpOperationTrackerFactory.INSTANCE, harness.getIOScheduler());
     }
 
     @Override
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeUpdateTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeUpdateTest.java
index 62843a2..ea80b36 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeUpdateTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeUpdateTest.java
@@ -54,7 +54,7 @@
         return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFlushController(),
-                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler());
     }
 
     @Override
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java
index e4cb37a..164c490 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java
@@ -53,7 +53,7 @@
         return LSMBTreeUtils.createLSMTree(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), typeTraits, cmpFactories, harness.getFlushController(),
-                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler());
     }
 
     @Override
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/LSMTreeRunner.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/LSMTreeRunner.java
index 3d74576..e9e0efb 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/LSMTreeRunner.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/LSMTreeRunner.java
@@ -42,7 +42,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.FlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ReferenceCountingOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.RefCountingOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
@@ -96,7 +96,7 @@
         this.ioScheduler = ImmediateScheduler.INSTANCE;
         lsmtree = LSMBTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ioManager, file, bufferCache, fmp,
                 typeTraits, cmpFactories, new FlushController(), NoMergePolicy.INSTANCE,
-                new ReferenceCountingOperationTracker(), ioScheduler);
+                RefCountingOperationTrackerFactory.INSTANCE, ioScheduler);
     }
 
     @Override
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestContext.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestContext.java
index 50a4447..72d6c8e 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestContext.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestContext.java
@@ -32,7 +32,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
@@ -67,12 +67,12 @@
             IInMemoryFreePageManager memFreePageManager, IOManager ioManager, FileReference file,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
             int numKeyFields, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
-            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) throws Exception {
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler) throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] cmpFactories = SerdeUtils.serdesToComparatorFactories(fieldSerdes, numKeyFields);
         LSMBTree lsmTree = LSMBTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ioManager, file,
                 diskBufferCache, diskFileMapProvider, typeTraits, cmpFactories, flushController, mergePolicy,
-                opTracker, ioScheduler);
+                opTrackerFactory, ioScheduler);
         LSMBTreeTestContext testCtx = new LSMBTreeTestContext(fieldSerdes, lsmTree);
         return testCtx;
     }
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java
index 62a2410..5e0f716 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java
@@ -36,13 +36,13 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.FlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ReferenceCountingOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.RefCountingOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
@@ -73,7 +73,7 @@
     protected ILSMIOOperationScheduler ioScheduler;
     protected ILSMFlushController flushController;
     protected ILSMMergePolicy mergePolicy;
-    protected ILSMOperationTracker opTracker;
+    protected ILSMOperationTrackerFactory opTrackerFactory;
 
     protected final Random rnd = new Random();
     protected final static SimpleDateFormat simpleDateFormat = new SimpleDateFormat("ddMMyy-hhmmssSS");
@@ -91,7 +91,7 @@
         this.ioScheduler = ImmediateScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
         this.flushController = new FlushController();
-        this.opTracker = new ReferenceCountingOperationTracker();
+        this.opTrackerFactory = RefCountingOperationTrackerFactory.INSTANCE;
     }
 
     public LSMBTreeTestHarness(int diskPageSize, int diskNumPages, int diskMaxOpenFiles, int memPageSize,
@@ -105,7 +105,7 @@
         this.ioScheduler = ImmediateScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
         this.flushController = new FlushController();
-        this.opTracker = new ReferenceCountingOperationTracker();
+        this.opTrackerFactory = RefCountingOperationTrackerFactory.INSTANCE;
     }
 
     public void setUp() throws HyracksException {
@@ -202,8 +202,8 @@
         return ioScheduler;
     }
 
-    public ILSMOperationTracker getOperationTracker() {
-        return opTracker;
+    public ILSMOperationTrackerFactory getOperationTrackerFactory() {
+        return opTrackerFactory;
     }
 
     public ILSMFlushController getFlushController() {
diff --git a/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/LSMInvertedIndexTestHarness.java b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/LSMInvertedIndexTestHarness.java
index 800c49b..71fe80f 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/LSMInvertedIndexTestHarness.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/LSMInvertedIndexTestHarness.java
@@ -34,13 +34,13 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.FlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ReferenceCountingOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.RefCountingOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
@@ -67,7 +67,7 @@
     protected ILSMIOOperationScheduler ioScheduler;
     protected ILSMFlushController flushController;
     protected ILSMMergePolicy mergePolicy;
-    protected ILSMOperationTracker opTracker;
+    protected ILSMOperationTrackerFactory opTrackerFactory;
 
     protected final Random rnd = new Random();
     protected final static SimpleDateFormat simpleDateFormat = new SimpleDateFormat("ddMMyy-hhmmssSS");
@@ -87,7 +87,7 @@
         this.ioScheduler = ImmediateScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
         this.flushController = new FlushController();
-        this.opTracker = new ReferenceCountingOperationTracker();
+        this.opTrackerFactory = RefCountingOperationTrackerFactory.INSTANCE;
     }
 
     public LSMInvertedIndexTestHarness(int diskPageSize, int diskNumPages, int diskMaxOpenFiles, int memPageSize,
@@ -101,7 +101,7 @@
         this.ioScheduler = ImmediateScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
         this.flushController = new FlushController();
-        this.opTracker = new ReferenceCountingOperationTracker();
+        this.opTrackerFactory = RefCountingOperationTrackerFactory.INSTANCE;
     }
 
     public void setUp() throws HyracksException {
@@ -203,8 +203,8 @@
         return ioScheduler;
     }
 
-    public ILSMOperationTracker getOperationTracker() {
-        return opTracker;
+    public ILSMOperationTrackerFactory getOperationTrackerFactory() {
+        return opTrackerFactory;
     }
 
     public ILSMFlushController getFlushController() {
diff --git a/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/LSMInvertedIndexTestContext.java b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/LSMInvertedIndexTestContext.java
index 45721b7..34b11c7 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/LSMInvertedIndexTestContext.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/LSMInvertedIndexTestContext.java
@@ -128,7 +128,7 @@
                         harness.getMemFreePageManager(), harness.getDiskFileMapProvider(), invListTypeTraits,
                         invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory,
                         harness.getDiskBufferCache(), harness.getIOManager(), harness.getOnDiskDir(),
-                        harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTracker(),
+                        harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTrackerFactory(),
                         harness.getIOScheduler());
                 break;
             }
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeBulkLoadTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeBulkLoadTest.java
index 04b5f81..bf7a5ef 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeBulkLoadTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeBulkLoadTest.java
@@ -57,7 +57,7 @@
         return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
-                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTracker(),
+                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTrackerFactory(),
                 harness.getIOScheduler());
     }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeDeleteTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeDeleteTest.java
index 3cd63da..3dc387e 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeDeleteTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeDeleteTest.java
@@ -57,7 +57,7 @@
         return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
-                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTracker(),
+                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTrackerFactory(),
                 harness.getIOScheduler());
     }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeExamplesTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeExamplesTest.java
index 7afeca1..f07dab0 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeExamplesTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeExamplesTest.java
@@ -41,7 +41,7 @@
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), typeTraits, rtreeCmpFactories, btreeCmpFactories,
                 valueProviderFactories, rtreePolicyType, harness.getFlushController(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler(),
+                harness.getOperationTrackerFactory(), harness.getIOScheduler(),
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length));
     }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeInsertTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeInsertTest.java
index e024b5a..6efbc72 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeInsertTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeInsertTest.java
@@ -57,7 +57,7 @@
         return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
-                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTracker(),
+                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTrackerFactory(),
                 harness.getIOScheduler());
     }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeLifecycleTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeLifecycleTest.java
index cfba169..fe10850 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeLifecycleTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeLifecycleTest.java
@@ -55,7 +55,7 @@
         testCtx = LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, RTreePolicyType.RTREE,
-                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTracker(),
+                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTrackerFactory(),
                 harness.getIOScheduler());
         index = testCtx.getIndex();
     }
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMergeTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMergeTest.java
index 249d0bc..3c492d8 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMergeTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMergeTest.java
@@ -56,7 +56,7 @@
         return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
-                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTracker(),
+                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTrackerFactory(),
                 harness.getIOScheduler());
     }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMultiBulkLoadTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMultiBulkLoadTest.java
index b37fe91..16a1f3e 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMultiBulkLoadTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMultiBulkLoadTest.java
@@ -57,7 +57,7 @@
         return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
-                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTracker(),
+                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTrackerFactory(),
                 harness.getIOScheduler());
     }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesBulkLoadTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesBulkLoadTest.java
index 5c5f1ec..dcc6478 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesBulkLoadTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesBulkLoadTest.java
@@ -58,7 +58,7 @@
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
                 numKeys, rtreePolicyType, harness.getFlushController(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getOperationTrackerFactory(), harness.getIOScheduler());
 
     }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesDeleteTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesDeleteTest.java
index 7720554..ce90ff6 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesDeleteTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesDeleteTest.java
@@ -58,7 +58,7 @@
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
                 numKeys, rtreePolicyType, harness.getFlushController(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getOperationTrackerFactory(), harness.getIOScheduler());
 
     }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesExamplesTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesExamplesTest.java
index 7dc65b3..acab6fe 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesExamplesTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesExamplesTest.java
@@ -41,7 +41,7 @@
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits, rtreeCmpFactories,
                 btreeCmpFactories, valueProviderFactories, rtreePolicyType, harness.getFlushController(),
-                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler(),
+                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler(),
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length));
     }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesInsertTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesInsertTest.java
index 235765a..8188595 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesInsertTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesInsertTest.java
@@ -58,7 +58,7 @@
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
                 numKeys, rtreePolicyType, harness.getFlushController(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getOperationTrackerFactory(), harness.getIOScheduler());
 
     }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesLifecycleTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesLifecycleTest.java
index 0930512..032f443 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesLifecycleTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesLifecycleTest.java
@@ -56,7 +56,7 @@
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
                 numKeys, RTreePolicyType.RTREE, harness.getFlushController(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getOperationTrackerFactory(), harness.getIOScheduler());
         index = testCtx.getIndex();
     }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMergeTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMergeTest.java
index 42f6f3f..fa7ceb5 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMergeTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMergeTest.java
@@ -57,7 +57,7 @@
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
                 numKeys, rtreePolicyType, harness.getFlushController(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getOperationTrackerFactory(), harness.getIOScheduler());
     }
 
     @Override
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMultiBulkLoadTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMultiBulkLoadTest.java
index 43f830b..237fc1d 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMultiBulkLoadTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMultiBulkLoadTest.java
@@ -58,7 +58,7 @@
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
                 numKeys, rtreePolicyType, harness.getFlushController(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler());
+                harness.getOperationTrackerFactory(), harness.getIOScheduler());
 
     }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java
index 324c557..cde9461 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java
@@ -61,7 +61,7 @@
                 harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), typeTraits, rtreeCmpFactories, btreeCmpFactories,
                 valueProviderFactories, rtreePolicyType, harness.getFlushController(), harness.getMergePolicy(),
-                harness.getOperationTracker(), harness.getIOScheduler(),
+                harness.getOperationTrackerFactory(), harness.getIOScheduler(),
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length));
     }
 
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java
index 2add7b1..ea900d7 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java
@@ -61,7 +61,7 @@
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits, rtreeCmpFactories,
                 btreeCmpFactories, valueProviderFactories, rtreePolicyType, harness.getFlushController(),
-                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler(),
+                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler(),
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length));
 
     }
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestContext.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestContext.java
index 409e245..c68f5e3 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestContext.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestContext.java
@@ -30,7 +30,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.impls.LSMRTree;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.utils.LSMRTreeUtils;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeTestContext;
@@ -71,8 +71,8 @@
             IInMemoryFreePageManager memFreePageManager, IOManager ioManager, FileReference file,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeyFields, RTreePolicyType rtreePolicyType,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler) throws Exception {
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler) throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] rtreeCmpFactories = SerdeUtils
                 .serdesToComparatorFactories(fieldSerdes, numKeyFields);
@@ -80,7 +80,7 @@
                 fieldSerdes.length);
         LSMRTree lsmTree = LSMRTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ioManager, file,
                 diskBufferCache, diskFileMapProvider, typeTraits, rtreeCmpFactories, btreeCmpFactories,
-                valueProviderFactories, rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler,
+                valueProviderFactories, rtreePolicyType, flushController, mergePolicy, opTrackerFactory, ioScheduler,
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length));
         LSMRTreeTestContext testCtx = new LSMRTreeTestContext(fieldSerdes, lsmTree);
         return testCtx;
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestHarness.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestHarness.java
index 57029cf..aed0d60 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestHarness.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestHarness.java
@@ -35,13 +35,13 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.FlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ReferenceCountingOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.RefCountingOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
@@ -69,7 +69,7 @@
     protected ILSMIOOperationScheduler ioScheduler;
     protected ILSMFlushController flushController;
     protected ILSMMergePolicy mergePolicy;
-    protected ILSMOperationTracker opTracker;
+    protected ILSMOperationTrackerFactory opTrackerFactory;
 
     protected final Random rnd = new Random();
     protected final static SimpleDateFormat simpleDateFormat = new SimpleDateFormat("ddMMyy-hhmmssSS");
@@ -87,7 +87,7 @@
         this.ioScheduler = ImmediateScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
         this.flushController = new FlushController();
-        this.opTracker = new ReferenceCountingOperationTracker();
+        this.opTrackerFactory = RefCountingOperationTrackerFactory.INSTANCE;
     }
 
     public LSMRTreeTestHarness(int diskPageSize, int diskNumPages, int diskMaxOpenFiles, int memPageSize,
@@ -101,7 +101,7 @@
         this.ioScheduler = ImmediateScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
         this.flushController = new FlushController();
-        this.opTracker = new ReferenceCountingOperationTracker();
+        this.opTrackerFactory = RefCountingOperationTrackerFactory.INSTANCE;
     }
 
     public void setUp() throws HyracksException {
@@ -201,8 +201,8 @@
         return ioScheduler;
     }
 
-    public ILSMOperationTracker getOperationTracker() {
-        return opTracker;
+    public ILSMOperationTrackerFactory getOperationTrackerFactory() {
+        return opTrackerFactory;
     }
 
     public ILSMFlushController getFlushController() {
diff --git a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeWithAntiMatterTuplesTestContext.java b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeWithAntiMatterTuplesTestContext.java
index e14365b..ebd8f72 100644
--- a/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeWithAntiMatterTuplesTestContext.java
+++ b/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeWithAntiMatterTuplesTestContext.java
@@ -30,7 +30,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.impls.LSMRTreeWithAntiMatterTuples;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.utils.LSMRTreeUtils;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeTestContext;
@@ -71,8 +71,8 @@
             IInMemoryFreePageManager memFreePageManager, IOManager ioManager, FileReference file,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeyFields, RTreePolicyType rtreePolicyType,
-            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler) throws Exception {
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler) throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] rtreeCmpFactories = SerdeUtils
                 .serdesToComparatorFactories(fieldSerdes, numKeyFields);
@@ -81,7 +81,7 @@
         LSMRTreeWithAntiMatterTuples lsmTree = LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(memBufferCache,
                 memFreePageManager, ioManager, file, diskBufferCache, diskFileMapProvider, typeTraits,
                 rtreeCmpFactories, btreeCmpFactories, valueProviderFactories, rtreePolicyType, flushController,
-                mergePolicy, opTracker, ioScheduler,
+                mergePolicy, opTrackerFactory, ioScheduler,
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length));
         LSMRTreeWithAntiMatterTuplesTestContext testCtx = new LSMRTreeWithAntiMatterTuplesTestContext(fieldSerdes,
                 lsmTree);