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 1687af8..8c019dc 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
@@ -19,8 +19,9 @@
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
 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.ImmediateFlushPolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.SequentialSchedulerProvider;
+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.ImmediateSchedulerProvider;
 import edu.uci.ics.hyracks.tests.am.common.LSMTreeOperatorTestHelper;
 
 public class LSMBTreeOperatorTestHelper extends LSMTreeOperatorTestHelper {
@@ -32,9 +33,9 @@
     }
 
     public IIndexDataflowHelperFactory createDataFlowHelperFactory() {
-        return new LSMBTreeDataflowHelperFactory(
-                new ImmediateFlushPolicyProvider(SequentialSchedulerProvider.INSTANCE),
-                new ConstantMergePolicyProvider(SequentialSchedulerProvider.INSTANCE, MERGE_THRESHOLD));
+        return new LSMBTreeDataflowHelperFactory(new FlushControllerProvider(), new ConstantMergePolicyProvider(
+                ImmediateSchedulerProvider.INSTANCE, MERGE_THRESHOLD), new RefCountingOperationTrackerProvider(),
+                ImmediateSchedulerProvider.INSTANCE);
     }
 
 }
diff --git a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/btree/LSMBTreePrimaryIndexScanOperatorTest.java b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/btree/LSMBTreePrimaryIndexScanOperatorTest.java
index e023feb..d751399 100644
--- a/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/btree/LSMBTreePrimaryIndexScanOperatorTest.java
+++ b/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/btree/LSMBTreePrimaryIndexScanOperatorTest.java
@@ -22,6 +22,7 @@
 import edu.uci.ics.hyracks.tests.am.common.ITreeIndexOperatorTestHelper;
 
 public class LSMBTreePrimaryIndexScanOperatorTest extends BTreePrimaryIndexScanOperatorTest {
+
     protected ITreeIndexOperatorTestHelper createTestHelper() throws HyracksException {
         return new LSMBTreeOperatorTestHelper(TestStorageManagerComponentHolder.getIOManager());
     }
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 f1652a5..3418e0b 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
@@ -20,8 +20,9 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ConstantMergePolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateFlushPolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.SequentialSchedulerProvider;
+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.ImmediateSchedulerProvider;
 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;
@@ -38,8 +39,9 @@
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             IBinaryComparatorFactory[] btreeComparatorFactories) {
         return new LSMRTreeDataflowHelperFactory(valueProviderFactories, rtreePolicyType, btreeComparatorFactories,
-                new ImmediateFlushPolicyProvider(SequentialSchedulerProvider.INSTANCE),
-                new ConstantMergePolicyProvider(SequentialSchedulerProvider.INSTANCE, MERGE_THRESHOLD));
+                new FlushControllerProvider(), new ConstantMergePolicyProvider(ImmediateSchedulerProvider.INSTANCE,
+                        MERGE_THRESHOLD), new RefCountingOperationTrackerProvider(),
+                ImmediateSchedulerProvider.INSTANCE);
     }
 
 }
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 bba4e2b..468c7ef 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
@@ -20,8 +20,9 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ConstantMergePolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateFlushPolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.SequentialSchedulerProvider;
+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.ImmediateSchedulerProvider;
 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;
@@ -29,7 +30,7 @@
 public class LSMRTreeWithAntiMatterTuplesOperatorTestHelper extends LSMTreeOperatorTestHelper {
 
     private static final int MERGE_THRESHOLD = 3;
-    
+
     public LSMRTreeWithAntiMatterTuplesOperatorTestHelper(IOManager ioManager) {
         super(ioManager);
     }
@@ -38,8 +39,9 @@
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             IBinaryComparatorFactory[] btreeComparatorFactories) {
         return new LSMRTreeWithAntiMatterTuplesDataflowHelperFactory(valueProviderFactories, rtreePolicyType,
-                btreeComparatorFactories, new ImmediateFlushPolicyProvider(SequentialSchedulerProvider.INSTANCE),
-                new ConstantMergePolicyProvider(SequentialSchedulerProvider.INSTANCE, MERGE_THRESHOLD));
+                btreeComparatorFactories, new FlushControllerProvider(), new ConstantMergePolicyProvider(
+                        ImmediateSchedulerProvider.INSTANCE, MERGE_THRESHOLD),
+                new RefCountingOperationTrackerProvider(), ImmediateSchedulerProvider.INSTANCE);
     }
 
 }
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 ded4570..907a2b5 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
@@ -25,8 +25,10 @@
 import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexDataflowHelper;
 import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeUtils;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 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.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
@@ -38,21 +40,28 @@
     private final int memPageSize;
     private final int memNumPages;
 
-    private final ILSMFlushPolicy flushPolicy;
+    private final ILSMFlushController flushController;
     private final ILSMMergePolicy mergePolicy;
+    private final ILSMOperationTracker opTracker;
+    private final ILSMIOScheduler ioScheduler;
 
     public LSMBTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            ILSMFlushPolicy flushPolicy, ILSMMergePolicy mergePolicy) {
-        this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES, flushPolicy, mergePolicy);
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMIOScheduler ioScheduler) {
+        this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES, flushController, mergePolicy,
+                opTracker, ioScheduler);
     }
 
     public LSMBTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            int memPageSize, int memNumPages, ILSMFlushPolicy flushPolicy, ILSMMergePolicy mergePolicy) {
+            int memPageSize, int memNumPages, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) {
         super(opDesc, ctx, partition);
         this.memPageSize = memPageSize;
         this.memNumPages = memNumPages;
-        this.flushPolicy = flushPolicy;
+        this.flushController = flushController;
         this.mergePolicy = mergePolicy;
+        this.opTracker = opTracker;
+        this.ioScheduler = ioScheduler;
     }
 
     @Override
@@ -66,9 +75,9 @@
             file.delete();
         }
         InMemoryFreePageManager memFreePageManager = new InMemoryFreePageManager(memNumPages, metaDataFrameFactory);
-        return LSMBTreeUtils.createLSMTree(memBufferCache, memFreePageManager,
-                ctx.getIOManager(), file.getFile().getPath(), opDesc.getStorageManager()
-                        .getBufferCache(ctx), opDesc.getStorageManager().getFileMapProvider(ctx), treeOpDesc
-                        .getTreeIndexTypeTraits(), treeOpDesc.getTreeIndexComparatorFactories(), flushPolicy, mergePolicy);
+        return LSMBTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ctx.getIOManager(), file.getFile()
+                .getPath(), opDesc.getStorageManager().getBufferCache(ctx), opDesc.getStorageManager()
+                .getFileMapProvider(ctx), treeOpDesc.getTreeIndexTypeTraits(), treeOpDesc
+                .getTreeIndexComparatorFactories(), flushController, mergePolicy, opTracker, 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 3cd6ffc..b05543b 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
@@ -19,26 +19,34 @@
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicyProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushControllerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
 
 public class LSMBTreeDataflowHelperFactory implements IIndexDataflowHelperFactory {
 
     private static final long serialVersionUID = 1L;
 
-    private final ILSMFlushPolicyProvider flushPolicyProvider;
+    private final ILSMFlushControllerProvider flushControllerProvider;
     private final ILSMMergePolicyProvider mergePolicyProvider;
+    private final ILSMOperationTrackerProvider opTrackerProvider;
+    private final ILSMIOSchedulerProvider ioSchedulerProvider;
 
-    public LSMBTreeDataflowHelperFactory(ILSMFlushPolicyProvider flushPolicyProvider,
-            ILSMMergePolicyProvider mergePolicyProvider) {
-        this.flushPolicyProvider = flushPolicyProvider;
+    public LSMBTreeDataflowHelperFactory(ILSMFlushControllerProvider flushControllerProvider,
+            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerProvider,
+            ILSMIOSchedulerProvider ioSchedulerProvider) {
+        this.flushControllerProvider = flushControllerProvider;
         this.mergePolicyProvider = mergePolicyProvider;
+        this.opTrackerProvider = opTrackerProvider;
+        this.ioSchedulerProvider = ioSchedulerProvider;
     }
 
     @Override
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
-        return new LSMBTreeDataflowHelper(opDesc, ctx, partition, flushPolicyProvider.getFlushPolicy(),
-                mergePolicyProvider.getMergePolicy());
+        return new LSMBTreeDataflowHelper(opDesc, ctx, partition, flushControllerProvider.getFlushController(),
+                mergePolicyProvider.getMergePolicy(), opTrackerProvider.getOperationTracker(),
+                ioSchedulerProvider.getIOScheduler());
     }
 }
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 8e9bf36..6742734 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
@@ -50,9 +50,11 @@
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponentFinalizer;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFileManager;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
 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.freepage.InMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BTreeFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMHarness;
@@ -95,8 +97,8 @@
             ITreeIndexFrameFactory interiorFrameFactory, ITreeIndexFrameFactory insertLeafFrameFactory,
             ITreeIndexFrameFactory deleteLeafFrameFactory, ILSMFileManager fileNameManager,
             BTreeFactory diskBTreeFactory, BTreeFactory bulkLoadBTreeFactory, IFileMapProvider diskFileMapProvider,
-            int fieldCount, IBinaryComparatorFactory[] cmpFactories, ILSMFlushPolicy flushPolicy,
-            ILSMMergePolicy mergePolicy) {
+            int fieldCount, IBinaryComparatorFactory[] cmpFactories, ILSMFlushController flushController,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) {
         memBTree = new BTree(memBufferCache, fieldCount, cmpFactories, memFreePageManager, interiorFrameFactory,
                 insertLeafFrameFactory);
         this.memFreePageManager = memFreePageManager;
@@ -109,7 +111,7 @@
         this.cmpFactories = cmpFactories;
         this.diskBTrees = new LinkedList<Object>();
         this.fileManager = fileNameManager;
-        lsmHarness = new LSMHarness(this, flushPolicy, mergePolicy);
+        lsmHarness = new LSMHarness(this, flushController, mergePolicy, opTracker, ioScheduler);
         componentFinalizer = new TreeIndexComponentFinalizer(diskFileMapProvider);
     }
 
@@ -348,41 +350,40 @@
         return diskBTrees;
     }
 
-	@Override
-	public ITreeIndexBulkLoader createBulkLoader(float fillLevel)
-			throws TreeIndexException {
-		return new LSMBTreeBulkLoader(fillLevel);
-	}
-	
-	public class LSMBTreeBulkLoader implements ITreeIndexBulkLoader {
-		private final BTree diskBTree;
-		private final BTreeBulkLoader bulkLoader;
+    @Override
+    public ITreeIndexBulkLoader createBulkLoader(float fillLevel) throws TreeIndexException {
+        return new LSMBTreeBulkLoader(fillLevel);
+    }
 
-		public LSMBTreeBulkLoader(float fillFactor) throws TreeIndexException {
-			try {
-				diskBTree = createBulkLoadTarget();
-			} catch (HyracksDataException e) {
-				throw new TreeIndexException(e);
-			}
-	        bulkLoader = (BTreeBulkLoader) diskBTree.createBulkLoader(0.7f);
-		}
+    public class LSMBTreeBulkLoader implements ITreeIndexBulkLoader {
+        private final BTree diskBTree;
+        private final BTreeBulkLoader bulkLoader;
 
-		@Override
-		public void add(ITupleReference tuple) throws HyracksDataException {
-			bulkLoader.add(tuple);
-		}
+        public LSMBTreeBulkLoader(float fillFactor) throws TreeIndexException {
+            try {
+                diskBTree = createBulkLoadTarget();
+            } catch (HyracksDataException e) {
+                throw new TreeIndexException(e);
+            }
+            bulkLoader = (BTreeBulkLoader) diskBTree.createBulkLoader(0.7f);
+        }
 
-		@Override
-		public void end() throws HyracksDataException {
-	        bulkLoader.end();
-	        lsmHarness.addBulkLoadedComponent(diskBTree);
-		}
-		
-	}
+        @Override
+        public void add(ITupleReference tuple) throws HyracksDataException {
+            bulkLoader.add(tuple);
+        }
 
-	@Deprecated
-	private ITreeIndexBulkLoader bulkloader;
-	
+        @Override
+        public void end() throws HyracksDataException {
+            bulkLoader.end();
+            lsmHarness.addBulkLoadedComponent(diskBTree);
+        }
+
+    }
+
+    @Deprecated
+    private ITreeIndexBulkLoader bulkloader;
+
     @Override
     public IIndexBulkLoadContext beginBulkLoad(float fillFactor) throws TreeIndexException, HyracksDataException {
         bulkloader = createBulkLoader(fillFactor);
@@ -475,4 +476,19 @@
     public IBufferCache getBufferCache() {
         return diskBufferCache;
     }
+
+    @Override
+    public ILSMFlushController getFlushController() {
+        return lsmHarness.getFlushController();
+    }
+
+    @Override
+    public ILSMOperationTracker getOperationTracker() {
+        return lsmHarness.getOperationTracker();
+    }
+
+    @Override
+    public ILSMIOScheduler getIOScheduler() {
+        return lsmHarness.getIOScheduler();
+    }
 }
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 f91912f..cd3f159 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
@@ -28,8 +28,10 @@
 import edu.uci.ics.hyracks.storage.am.lsm.btree.tuples.LSMBTreeCopyTupleWriterFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.tuples.LSMBTreeTupleWriterFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFileManager;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 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.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BTreeFactory;
@@ -38,10 +40,11 @@
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
 public class LSMBTreeUtils {
-    public static LSMBTree createLSMTree(InMemoryBufferCache memBufferCache, InMemoryFreePageManager memFreePageManager,
-            IIOManager ioManager, String onDiskDir, IBufferCache diskBufferCache,
-            IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits, IBinaryComparatorFactory[] cmpFactories,
-            ILSMFlushPolicy flushPolicy, ILSMMergePolicy mergePolicy) {
+    public static LSMBTree createLSMTree(InMemoryBufferCache memBufferCache,
+            InMemoryFreePageManager memFreePageManager, IIOManager ioManager, String onDiskDir,
+            IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
+            IBinaryComparatorFactory[] cmpFactories, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) {
         LSMBTreeTupleWriterFactory insertTupleWriterFactory = new LSMBTreeTupleWriterFactory(typeTraits,
                 cmpFactories.length, false);
         LSMBTreeTupleWriterFactory deleteTupleWriterFactory = new LSMBTreeTupleWriterFactory(typeTraits,
@@ -55,14 +58,15 @@
         ITreeIndexMetaDataFrameFactory metaFrameFactory = new LIFOMetaDataFrameFactory();
         LinkedListFreePageManagerFactory freePageManagerFactory = new LinkedListFreePageManagerFactory(diskBufferCache,
                 metaFrameFactory);
-        BTreeFactory diskBTreeFactory = new BTreeFactory(diskBufferCache, freePageManagerFactory,
-                cmpFactories, typeTraits.length, interiorFrameFactory, copyTupleLeafFrameFactory);
-        BTreeFactory bulkLoadBTreeFactory = new BTreeFactory(diskBufferCache, freePageManagerFactory,
-                cmpFactories, typeTraits.length, interiorFrameFactory, insertLeafFrameFactory);
+        BTreeFactory diskBTreeFactory = new BTreeFactory(diskBufferCache, freePageManagerFactory, cmpFactories,
+                typeTraits.length, interiorFrameFactory, copyTupleLeafFrameFactory);
+        BTreeFactory bulkLoadBTreeFactory = new BTreeFactory(diskBufferCache, freePageManagerFactory, cmpFactories,
+                typeTraits.length, interiorFrameFactory, insertLeafFrameFactory);
         ILSMFileManager fileNameManager = new LSMTreeFileManager(ioManager, diskFileMapProvider, onDiskDir);
-        LSMBTree lsmTree = new LSMBTree(memBufferCache, memFreePageManager, interiorFrameFactory, insertLeafFrameFactory,
-                deleteLeafFrameFactory, fileNameManager, diskBTreeFactory, bulkLoadBTreeFactory,
-                diskFileMapProvider, typeTraits.length, cmpFactories, flushPolicy, mergePolicy);
+        LSMBTree lsmTree = new LSMBTree(memBufferCache, memFreePageManager, interiorFrameFactory,
+                insertLeafFrameFactory, deleteLeafFrameFactory, fileNameManager, diskBTreeFactory,
+                bulkLoadBTreeFactory, diskFileMapProvider, typeTraits.length, cmpFactories, flushController, mergePolicy,
+                opTracker, ioScheduler);
         return lsmTree;
     }
 }
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMFlushController.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMFlushController.java
new file mode 100644
index 0000000..fb58880
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMFlushController.java
@@ -0,0 +1,7 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+public interface ILSMFlushController {
+    public void setFlushStatus(ILSMIndex index, boolean needsFlush);
+
+    public boolean getFlushStatus(ILSMIndex index);
+}
\ No newline at end of file
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMFlushControllerProvider.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMFlushControllerProvider.java
new file mode 100644
index 0000000..d62b8b4
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMFlushControllerProvider.java
@@ -0,0 +1,7 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.io.Serializable;
+
+public interface ILSMFlushControllerProvider extends Serializable {
+    public ILSMFlushController getFlushController();
+}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMFlushPolicy.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMFlushPolicy.java
deleted file mode 100644
index a977911..0000000
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMFlushPolicy.java
+++ /dev/null
@@ -1,6 +0,0 @@
-package edu.uci.ics.hyracks.storage.am.lsm.common.api;
-
-
-public interface ILSMFlushPolicy {
-    public void memoryComponentExceededThreshold(ILSMIndex index);
-}
\ No newline at end of file
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMFlushPolicyProvider.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMFlushPolicyProvider.java
deleted file mode 100644
index 9e48f40..0000000
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMFlushPolicyProvider.java
+++ /dev/null
@@ -1,7 +0,0 @@
-package edu.uci.ics.hyracks.storage.am.lsm.common.api;
-
-import java.io.Serializable;
-
-public interface ILSMFlushPolicyProvider extends Serializable {
-    public ILSMFlushPolicy getFlushPolicy();
-}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java
index da5a8bb..0698295 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMHarness.java
@@ -60,4 +60,10 @@
     public List<Object> getDiskComponents();
 
     public ILSMComponentFinalizer getComponentFinalizer();
+
+    public ILSMFlushController getFlushController();
+
+    public ILSMOperationTracker getOperationTracker();
+
+    public ILSMIOScheduler getIOScheduler();
 }
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOScheduler.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOScheduler.java
index 866e208..6929232 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOScheduler.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOScheduler.java
@@ -4,4 +4,6 @@
     public void scheduleFlush(ILSMIndex index);
 
     public void scheduleMerge(ILSMIndex index);
+
+    public void shutdown();
 }
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java
index 0c163eb..f934ed1 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndex.java
@@ -60,4 +60,10 @@
     public List<Object> getDiskComponents();
 
     public ILSMComponentFinalizer getComponentFinalizer();
+
+    public ILSMFlushController getFlushController();
+
+    public ILSMOperationTracker getOperationTracker();
+
+    public ILSMIOScheduler getIOScheduler();
 }
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
new file mode 100644
index 0000000..b845bd0
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java
@@ -0,0 +1,8 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+
+public interface ILSMOperationTracker {
+    public void threadEnter(ILSMIndex index);
+
+    public void threadExit(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
new file mode 100644
index 0000000..7bb638b
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerProvider.java
@@ -0,0 +1,8 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.io.Serializable;
+
+
+public interface ILSMOperationTrackerProvider extends Serializable {
+    public ILSMOperationTracker getOperationTracker();
+}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/FlushController.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/FlushController.java
new file mode 100644
index 0000000..6fd18f9
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/FlushController.java
@@ -0,0 +1,19 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
+
+public class FlushController implements ILSMFlushController {
+
+    private boolean needsFlush = false;
+
+    @Override
+    public void setFlushStatus(ILSMIndex index, boolean needsFlush) {
+        this.needsFlush = needsFlush;
+    }
+
+    @Override
+    public boolean getFlushStatus(ILSMIndex index) {
+        return needsFlush;
+    }
+}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/FlushControllerProvider.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/FlushControllerProvider.java
new file mode 100644
index 0000000..22807e4
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/FlushControllerProvider.java
@@ -0,0 +1,15 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushControllerProvider;
+
+public class FlushControllerProvider implements ILSMFlushControllerProvider {
+
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    public ILSMFlushController getFlushController() {
+        return new FlushController();
+    }
+
+}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateFlushPolicy.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateFlushPolicy.java
deleted file mode 100644
index 0fb6545..0000000
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateFlushPolicy.java
+++ /dev/null
@@ -1,20 +0,0 @@
-package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
-
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
-
-public class ImmediateFlushPolicy implements ILSMFlushPolicy {
-
-    private final ILSMIOScheduler ioScheduler;
-
-    public ImmediateFlushPolicy(ILSMIOScheduler ioScheduler) {
-        this.ioScheduler = ioScheduler;
-    }
-
-    @Override
-    public void memoryComponentExceededThreshold(final ILSMIndex index) {
-        // Schedule a flush immediately when the memory component is full
-        ioScheduler.scheduleFlush(index);
-    }
-}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateFlushPolicyProvider.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateFlushPolicyProvider.java
deleted file mode 100644
index 8e73c09..0000000
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateFlushPolicyProvider.java
+++ /dev/null
@@ -1,22 +0,0 @@
-package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
-
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOSchedulerProvider;
-
-public class ImmediateFlushPolicyProvider implements ILSMFlushPolicyProvider {
-
-    private static final long serialVersionUID = 1L;
-
-    private final ILSMIOSchedulerProvider schedulerProvider;
-
-    public ImmediateFlushPolicyProvider(ILSMIOSchedulerProvider schedulerProvider) {
-        this.schedulerProvider = schedulerProvider;
-    }
-
-    @Override
-    public ILSMFlushPolicy getFlushPolicy() {
-        return new ImmediateFlushPolicy(schedulerProvider.getIOScheduler());
-    }
-
-}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateScheduler.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateScheduler.java
new file mode 100644
index 0000000..7c76953
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateScheduler.java
@@ -0,0 +1,43 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
+
+public enum ImmediateScheduler implements ILSMIOScheduler {
+    INSTANCE;
+
+    @Override
+    public void scheduleFlush(final ILSMIndex index) {
+        try {
+            ((ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE))
+                    .flush();
+        } catch (HyracksDataException e) {
+            e.printStackTrace();
+        } catch (IndexException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @Override
+    public void scheduleMerge(final ILSMIndex index) {
+        try {
+            ((ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE))
+                    .merge();
+        } catch (LSMMergeInProgressException e) {
+            // Ignore!
+        } catch (HyracksDataException e) {
+            e.printStackTrace();
+        } catch (IndexException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @Override
+    public void shutdown() {
+    }
+
+}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SequentialSchedulerProvider.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateSchedulerProvider.java
similarity index 70%
rename from hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SequentialSchedulerProvider.java
rename to hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateSchedulerProvider.java
index 83e2136..3341059 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SequentialSchedulerProvider.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateSchedulerProvider.java
@@ -3,12 +3,12 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOSchedulerProvider;
 
-public enum SequentialSchedulerProvider implements ILSMIOSchedulerProvider {
+public enum ImmediateSchedulerProvider implements ILSMIOSchedulerProvider {
     INSTANCE;
 
     @Override
     public ILSMIOScheduler getIOScheduler() {
-        return SequentialScheduler.INSTANCE;
+        return ImmediateScheduler.INSTANCE;
     }
 
 }
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 7900b29..42d1277 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
@@ -28,9 +28,11 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexOpContext;
 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.lsm.common.api.ILSMFlushPolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 
 /**
  * Common code for synchronizing LSM operations like
@@ -51,11 +53,6 @@
     // All accesses to the LSM-Tree's on-disk components are synchronized on diskComponentsSync.
     private Object diskComponentsSync = new Object();
 
-    // For synchronizing all operations with flushes.
-    // Currently, all operations block during a flush.
-    private int threadRefCount;
-    private boolean flushFlag;
-
     // For synchronizing searchers with a concurrent merge.
     private AtomicBoolean isMerging = new AtomicBoolean(false);
     private AtomicInteger searcherRefCountA = new AtomicInteger(0);
@@ -67,56 +64,30 @@
     private AtomicInteger searcherRefCount = searcherRefCountA;
 
     // Flush and Merge Policies
-    private final ILSMFlushPolicy flushPolicy;
+    private final ILSMFlushController flushController;
     private final ILSMMergePolicy mergePolicy;
+    private final ILSMOperationTracker opTracker;
+    private final ILSMIOScheduler ioScheduler;
 
-    public LSMHarness(ILSMIndex lsmIndex, ILSMFlushPolicy flushPolicy, ILSMMergePolicy mergePolicy) {
+    public LSMHarness(ILSMIndex lsmIndex, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) {
         this.lsmIndex = lsmIndex;
-        this.threadRefCount = 0;
-        this.flushPolicy = flushPolicy;
+        this.opTracker = opTracker;
+        this.flushController = flushController;
         this.mergePolicy = mergePolicy;
-        this.flushFlag = false;
+        this.ioScheduler = ioScheduler;
     }
 
-    public void threadEnter() {
-        threadRefCount++;
-    }
-
-    public void threadExit() throws HyracksDataException, IndexException {
-        synchronized (this) {
-            threadRefCount--;
-
-            // Check if we've reached or exceeded the maximum number of pages.
-            if (!flushFlag && lsmIndex.getInMemoryFreePageManager().isFull()) {
-                flushFlag = true;
-            }
-
-            // Flush will only be handled by last exiting thread.
-            if (flushFlag && threadRefCount == 0) {
-                flushPolicy.memoryComponentExceededThreshold(lsmIndex);
-            }
+    private void threadExit() {
+        if (!lsmIndex.getFlushController().getFlushStatus(lsmIndex) && lsmIndex.getInMemoryFreePageManager().isFull()) {
+            lsmIndex.getFlushController().setFlushStatus(lsmIndex, true);
         }
+        opTracker.threadExit(lsmIndex);
     }
 
     public void insertUpdateOrDelete(ITupleReference tuple, IIndexOpContext ctx) throws HyracksDataException,
             IndexException {
-        boolean waitForFlush = true;
-        do {
-            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 (!flushFlag) {
-                    // Increment the threadRefCount in order to block the possibility of a concurrent flush.
-                    // The corresponding threadExit() call is in LSMTreeRangeSearchCursor.close()
-                    threadEnter();
-
-                    // A flush is not pending, so proceed with the operation.
-                    waitForFlush = false;
-                }
-            }
-        } while (waitForFlush);
-
+        opTracker.threadEnter(lsmIndex);
         // 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.
@@ -149,7 +120,7 @@
         }
 
         // Unblock entering threads waiting for the flush
-        flushFlag = false;
+        flushController.setFlushStatus(lsmIndex, false);
     }
 
     public List<Object> search(IIndexCursor cursor, ISearchPredicate pred, IIndexOpContext ctx,
@@ -157,22 +128,7 @@
         // If the search doesn't include the in-memory component, then we don't have
         // to synchronize with a flush.
         if (includeMemComponent) {
-            boolean waitForFlush = true;
-            do {
-                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 (!flushFlag) {
-                        // Increment the threadRefCount in order to block the possibility of a concurrent flush.
-                        // The corresponding threadExit() call is in LSMTreeRangeSearchCursor.close()
-                        threadEnter();
-
-                        // A flush is not pending, so proceed with the operation.
-                        waitForFlush = false;
-                    }
-                }
-            } while (waitForFlush);
+            opTracker.threadEnter(lsmIndex);
         }
 
         // Get a snapshot of the current on-disk Trees.
@@ -259,11 +215,7 @@
         // If the in-memory Tree was not included in the search, then we don't
         // need to synchronize with a flush.
         if (includeMemComponent) {
-            try {
-                threadExit();
-            } catch (IndexException e) {
-                throw new HyracksDataException(e);
-            }
+            threadExit();
         }
         // 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
@@ -282,4 +234,16 @@
             mergePolicy.diskComponentAdded(lsmIndex, lsmIndex.getDiskComponents().size());
         }
     }
+
+    public ILSMFlushController getFlushController() {
+        return flushController;
+    }
+
+    public ILSMOperationTracker getOperationTracker() {
+        return opTracker;
+    }
+
+    public ILSMIOScheduler getIOScheduler() {
+        return ioScheduler;
+    }
 }
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/RefCountingOperationTracker.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/RefCountingOperationTracker.java
new file mode 100644
index 0000000..aeb1227
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/RefCountingOperationTracker.java
@@ -0,0 +1,42 @@
+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;
+
+public class RefCountingOperationTracker implements ILSMOperationTracker {
+
+    private int threadRefCount = 0;
+
+    @Override
+    public void threadEnter(ILSMIndex index) {
+        boolean waitForFlush = true;
+        do {
+            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()
+                    threadRefCount++;
+
+                    // A flush is not pending, so proceed with the operation.
+                    waitForFlush = false;
+                }
+            }
+        } while (waitForFlush);
+    }
+
+    @Override
+    public void threadExit(ILSMIndex index) {
+        synchronized (this) {
+            threadRefCount--;
+
+            // Flush will only be handled by last exiting thread.
+            if (index.getFlushController().getFlushStatus(index) && threadRefCount == 0) {
+                index.getIOScheduler().scheduleFlush(index);
+            }
+        }
+    }
+
+}
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
new file mode 100644
index 0000000..e32e697
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/RefCountingOperationTrackerProvider.java
@@ -0,0 +1,15 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+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() {
+        return new RefCountingOperationTracker();
+    }
+
+}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SequentialScheduler.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SequentialScheduler.java
deleted file mode 100644
index 90ef3e3..0000000
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/SequentialScheduler.java
+++ /dev/null
@@ -1,56 +0,0 @@
-package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
-
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
-import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
-
-public enum SequentialScheduler implements ILSMIOScheduler {
-    INSTANCE;
-
-    private final ExecutorService executor = Executors.newSingleThreadExecutor();
-
-    @Override
-    public void scheduleFlush(final ILSMIndex index) {
-        executor.submit(new Runnable() {
-
-            @Override
-            public void run() {
-                try {
-                    ((ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
-                            NoOpOperationCallback.INSTANCE)).flush();
-                } catch (HyracksDataException e) {
-                    e.printStackTrace();
-                } catch (IndexException e) {
-                    e.printStackTrace();
-                }
-            }
-        });
-    }
-
-    @Override
-    public void scheduleMerge(final ILSMIndex index) {
-        executor.submit(new Runnable() {
-
-            @Override
-            public void run() {
-                try {
-                    ((ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
-                            NoOpOperationCallback.INSTANCE)).merge();
-                } catch (LSMMergeInProgressException e) {
-                    // Ignore!
-                } catch (HyracksDataException e) {
-                    e.printStackTrace();
-                } catch (IndexException e) {
-                    e.printStackTrace();
-                }
-            }
-        });
-    }
-
-}
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 d96aea9..c7bd9a5 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
@@ -22,15 +22,16 @@
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.api.io.IIOManager;
 import edu.uci.ics.hyracks.dataflow.std.file.IFileSplitProvider;
-import edu.uci.ics.hyracks.storage.am.common.api.IOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexDataflowHelper;
 import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 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.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.impls.LSMRTreeInMemoryBufferCache;
@@ -50,36 +51,35 @@
     protected final IBinaryComparatorFactory[] btreeComparatorFactories;
     protected final IPrimitiveValueProviderFactory[] valueProviderFactories;
     protected final RTreePolicyType rtreePolicyType;
-    protected final ILSMFlushPolicy flushPolicy;
+    protected final ILSMFlushController flushController;
     protected final ILSMMergePolicy mergePolicy;
+    protected final ILSMOperationTracker opTracker;
+    protected final ILSMIOScheduler ioScheduler;
 
     public AbstractLSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
             IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushPolicy flushPolicy, ILSMMergePolicy mergePolicy) {
-        super(opDesc, ctx, partition);
-        memPageSize = DEFAULT_MEM_PAGE_SIZE;
-        memNumPages = DEFAULT_MEM_NUM_PAGES;
-        this.btreeComparatorFactories = btreeComparatorFactories;
-        this.valueProviderFactories = valueProviderFactories;
-        this.rtreePolicyType = rtreePolicyType;
-        this.flushPolicy = flushPolicy;
-        this.mergePolicy = mergePolicy;
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMIOScheduler ioScheduler) {
+        this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES, btreeComparatorFactories,
+                valueProviderFactories, rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler);
     }
 
-    public AbstractLSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
-            IOperationCallbackProvider opCallbackProvider, int partition, boolean createIfNotExists, int memPageSize,
-            int memNumPages, IBinaryComparatorFactory[] btreeComparatorFactories,
+    public AbstractLSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
+            int memPageSize, int memNumPages, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushPolicy flushPolicy, ILSMMergePolicy mergePolicy) {
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMIOScheduler ioScheduler) {
         super(opDesc, ctx, partition);
         this.memPageSize = memPageSize;
         this.memNumPages = memNumPages;
         this.btreeComparatorFactories = btreeComparatorFactories;
         this.valueProviderFactories = valueProviderFactories;
         this.rtreePolicyType = rtreePolicyType;
-        this.flushPolicy = flushPolicy;
+        this.flushController = flushController;
         this.mergePolicy = mergePolicy;
+        this.opTracker = opTracker;
+        this.ioScheduler = ioScheduler;
     }
 
     @Override
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 5a09621..cf9ac0a 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
@@ -20,13 +20,14 @@
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.IIOManager;
-import edu.uci.ics.hyracks.storage.am.common.api.IOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 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.freepage.InMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.utils.LSMRTreeUtils;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
@@ -38,18 +39,19 @@
     public LSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
             IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushPolicy flushPolicy, ILSMMergePolicy mergePolicy) {
-        super(opDesc, ctx, partition, btreeComparatorFactories, valueProviderFactories, rtreePolicyType, flushPolicy,
-                mergePolicy);
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMIOScheduler ioScheduler) {
+        super(opDesc, ctx, partition, btreeComparatorFactories, valueProviderFactories, rtreePolicyType,
+                flushController, mergePolicy, opTracker, ioScheduler);
     }
 
-    public LSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
-            IOperationCallbackProvider opCallbackProvider, int partition, boolean createIfNotExists, int memPageSize,
-            int memNumPages, IBinaryComparatorFactory[] btreeComparatorFactories,
+    public LSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
+            int memPageSize, int memNumPages, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushPolicy flushPolicy, ILSMMergePolicy mergePolicy) {
-        super(opDesc, ctx, opCallbackProvider, partition, createIfNotExists, memPageSize, memNumPages,
-                btreeComparatorFactories, valueProviderFactories, rtreePolicyType, flushPolicy, mergePolicy);
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMIOScheduler ioScheduler) {
+        super(opDesc, ctx, partition, memPageSize, memNumPages, btreeComparatorFactories, valueProviderFactories,
+                rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler);
     }
 
     @Override
@@ -61,7 +63,7 @@
         try {
             return LSMRTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ioManager, onDiskDir,
                     diskBufferCache, diskFileMapProvider, typeTraits, rtreeCmpFactories, btreeCmpFactories,
-                    valueProviderFactories, rtreePolicyType, flushPolicy, mergePolicy);
+                    valueProviderFactories, rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler);
         } 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 91ff2cb..aab6fcc 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
@@ -21,8 +21,10 @@
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicyProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushControllerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOSchedulerProvider;
 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.rtree.frames.RTreePolicyType;
 
 public class LSMRTreeDataflowHelperFactory implements IIndexDataflowHelperFactory {
@@ -32,24 +34,29 @@
     private final IBinaryComparatorFactory[] btreeComparatorFactories;
     private final IPrimitiveValueProviderFactory[] valueProviderFactories;
     private final RTreePolicyType rtreePolicyType;
-    private final ILSMFlushPolicyProvider flushPolicyProvider;
+    private final ILSMFlushControllerProvider flushControllerProvider;
     private final ILSMMergePolicyProvider mergePolicyProvider;
+    private final ILSMOperationTrackerProvider opTrackerProvider;
+    private final ILSMIOSchedulerProvider ioSchedulerProvider;
 
     public LSMRTreeDataflowHelperFactory(IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType, IBinaryComparatorFactory[] btreeComparatorFactories,
-            ILSMFlushPolicyProvider flushPolicyProvider,
-            ILSMMergePolicyProvider mergePolicyProvider) {
+            ILSMFlushControllerProvider flushControllerProvider, ILSMMergePolicyProvider mergePolicyProvider,
+            ILSMOperationTrackerProvider opTrackerProvider, ILSMIOSchedulerProvider ioSchedulerProvider) {
         this.btreeComparatorFactories = btreeComparatorFactories;
         this.valueProviderFactories = valueProviderFactories;
         this.rtreePolicyType = rtreePolicyType;
-        this.flushPolicyProvider = flushPolicyProvider;
+        this.flushControllerProvider = flushControllerProvider;
         this.mergePolicyProvider = mergePolicyProvider;
+        this.opTrackerProvider = opTrackerProvider;
+        this.ioSchedulerProvider = ioSchedulerProvider;
     }
 
     @Override
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
         return new LSMRTreeDataflowHelper(opDesc, ctx, partition, btreeComparatorFactories, valueProviderFactories,
-                rtreePolicyType, flushPolicyProvider.getFlushPolicy(), mergePolicyProvider.getMergePolicy());
+                rtreePolicyType, flushControllerProvider.getFlushController(), mergePolicyProvider.getMergePolicy(),
+                opTrackerProvider.getOperationTracker(), ioSchedulerProvider.getIOScheduler());
     }
 }
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 f8b9dfa..1371161 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
@@ -20,13 +20,14 @@
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.IIOManager;
-import edu.uci.ics.hyracks.storage.am.common.api.IOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 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.freepage.InMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.utils.LSMRTreeUtils;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
@@ -37,17 +38,19 @@
     public LSMRTreeWithAntiMatterTuplesDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushPolicy flushPolicy, ILSMMergePolicy mergePolicy) {
-        super(opDesc, ctx, partition, btreeComparatorFactories, valueProviderFactories, rtreePolicyType, flushPolicy, mergePolicy);
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMIOScheduler ioScheduler) {
+        super(opDesc, ctx, partition, btreeComparatorFactories, valueProviderFactories, rtreePolicyType,
+                flushController, mergePolicy, opTracker, ioScheduler);
     }
 
     public LSMRTreeWithAntiMatterTuplesDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
-            IOperationCallbackProvider opCallbackProvider, int partition, boolean createIfNotExists, int memPageSize,
-            int memNumPages, IBinaryComparatorFactory[] btreeComparatorFactories,
+            int partition, int memPageSize, int memNumPages, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushPolicy flushPolicy, ILSMMergePolicy mergePolicy) {
-        super(opDesc, ctx, opCallbackProvider, partition, createIfNotExists, memPageSize, memNumPages,
-                btreeComparatorFactories, valueProviderFactories, rtreePolicyType, flushPolicy, mergePolicy);
+            ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMIOScheduler ioScheduler) {
+        super(opDesc, ctx, partition, memPageSize, memNumPages, btreeComparatorFactories, valueProviderFactories,
+                rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler);
     }
 
     @Override
@@ -59,7 +62,7 @@
         try {
             return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(memBufferCache, memFreePageManager, ioManager,
                     onDiskDir, diskBufferCache, diskFileMapProvider, typeTraits, rtreeCmpFactories, btreeCmpFactories,
-                    valueProviderFactories, rtreePolicyType, flushPolicy, mergePolicy);
+                    valueProviderFactories, rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler);
         } 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 5fc49a9..af6b962 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
@@ -21,8 +21,10 @@
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IndexDataflowHelper;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicyProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushControllerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOSchedulerProvider;
 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.rtree.frames.RTreePolicyType;
 
 public class LSMRTreeWithAntiMatterTuplesDataflowHelperFactory implements IIndexDataflowHelperFactory {
@@ -32,24 +34,30 @@
     private final IBinaryComparatorFactory[] btreeComparatorFactories;
     private final IPrimitiveValueProviderFactory[] valueProviderFactories;
     private final RTreePolicyType rtreePolicyType;
-    private final ILSMFlushPolicyProvider flushPolicyProvider;
+    private final ILSMFlushControllerProvider flushControllerProvider;
     private final ILSMMergePolicyProvider mergePolicyProvider;
+    private final ILSMOperationTrackerProvider opTrackerProvider;
+    private final ILSMIOSchedulerProvider ioSchedulerProvider;
 
     public LSMRTreeWithAntiMatterTuplesDataflowHelperFactory(IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType, IBinaryComparatorFactory[] btreeComparatorFactories,
-            ILSMFlushPolicyProvider flushPolicyProvider,
-            ILSMMergePolicyProvider mergePolicyProvider) {
+            ILSMFlushControllerProvider flushControllerProvider, ILSMMergePolicyProvider mergePolicyProvider,
+            ILSMOperationTrackerProvider opTrackerProvider, ILSMIOSchedulerProvider ioSchedulerProvider) {
         this.btreeComparatorFactories = btreeComparatorFactories;
         this.valueProviderFactories = valueProviderFactories;
         this.rtreePolicyType = rtreePolicyType;
-        this.flushPolicyProvider = flushPolicyProvider;
+        this.flushControllerProvider = flushControllerProvider;
         this.mergePolicyProvider = mergePolicyProvider;
+        this.ioSchedulerProvider = ioSchedulerProvider;
+        this.opTrackerProvider = opTrackerProvider;
     }
 
     @Override
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
         return new LSMRTreeWithAntiMatterTuplesDataflowHelper(opDesc, ctx, partition, btreeComparatorFactories,
-                valueProviderFactories, rtreePolicyType, flushPolicyProvider.getFlushPolicy(), mergePolicyProvider.getMergePolicy());
+                valueProviderFactories, rtreePolicyType, flushControllerProvider.getFlushController(),
+                mergePolicyProvider.getMergePolicy(), opTrackerProvider.getOperationTracker(),
+                ioSchedulerProvider.getIOScheduler());
     }
 }
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 7e61d2e..807548c 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
@@ -40,9 +40,11 @@
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOp;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponentFinalizer;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFileManager;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
 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.freepage.InMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.TreeFactory;
@@ -117,12 +119,13 @@
             ILSMFileManager fileManager, RTreeFactory diskRTreeFactory, IFileMapProvider diskFileMapProvider,
             ILSMComponentFinalizer componentFinalizer, int fieldCount, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, ILinearizeComparatorFactory linearizer,
-            int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, ILSMFlushPolicy flushPolicy, ILSMMergePolicy mergePolicy) {
+            int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, ILSMFlushController flushController,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) {
         RTree memRTree = new RTree(memBufferCache, fieldCount, rtreeCmpFactories, memFreePageManager,
                 rtreeInteriorFrameFactory, rtreeLeafFrameFactory);
         // TODO: Do we need another operation callback here?
-        BTree memBTree = new BTree(memBufferCache, fieldCount, btreeCmpFactories,
-                memFreePageManager, btreeInteriorFrameFactory, btreeLeafFrameFactory);
+        BTree memBTree = new BTree(memBufferCache, fieldCount, btreeCmpFactories, memFreePageManager,
+                btreeInteriorFrameFactory, btreeLeafFrameFactory);
         memComponent = new LSMRTreeComponent(memRTree, memBTree);
         this.memFreePageManager = memFreePageManager;
         this.diskBufferCache = diskRTreeFactory.getBufferCache();
@@ -135,7 +138,7 @@
         this.diskRTreeFactory = diskRTreeFactory;
         this.btreeCmpFactories = btreeCmpFactories;
         this.rtreeCmpFactories = rtreeCmpFactories;
-        this.lsmHarness = new LSMHarness(this, flushPolicy, mergePolicy);
+        this.lsmHarness = new LSMHarness(this, flushController, mergePolicy, opTracker, ioScheduler);
         this.componentFinalizer = componentFinalizer;
         this.linearizer = linearizer;
         this.comparatorFields = comparatorFields;
@@ -342,4 +345,18 @@
         return componentFinalizer;
     }
 
+    @Override
+    public ILSMFlushController getFlushController() {
+        return lsmHarness.getFlushController();
+    }
+
+    @Override
+    public ILSMOperationTracker getOperationTracker() {
+        return lsmHarness.getOperationTracker();
+    }
+
+    @Override
+    public ILSMIOScheduler getIOScheduler() {
+        return lsmHarness.getIOScheduler();
+    }
 }
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 2528d3d..871768c 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
@@ -43,8 +43,10 @@
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFileManager;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 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.freepage.InMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BTreeFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMHarness;
@@ -69,11 +71,12 @@
             ILSMFileManager fileManager, RTreeFactory diskRTreeFactory, BTreeFactory diskBTreeFactory,
             IFileMapProvider diskFileMapProvider, int fieldCount, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, ILinearizeComparatorFactory linearizer,
-            int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, ILSMFlushPolicy flushPolicy, ILSMMergePolicy mergePolicy) {
+            int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, ILSMFlushController flushController,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) {
         super(memBufferCache, memFreePageManager, rtreeInteriorFrameFactory, rtreeLeafFrameFactory,
                 btreeInteriorFrameFactory, btreeLeafFrameFactory, fileManager, diskRTreeFactory, diskFileMapProvider,
                 new LSMRTreeComponentFinalizer(diskFileMapProvider), fieldCount, rtreeCmpFactories, btreeCmpFactories,
-                linearizer, comparatorFields, linearizerArray, flushPolicy, mergePolicy);
+                linearizer, comparatorFields, linearizerArray, flushController, mergePolicy, opTracker, ioScheduler);
         this.diskBTreeFactory = diskBTreeFactory;
     }
 
@@ -159,7 +162,8 @@
 
         LSMRTreeCursorInitialState initialState = new LSMRTreeCursorInitialState(numTrees, rtreeLeafFrameFactory,
                 rtreeInteriorFrameFactory, btreeLeafFrameFactory, ctx.getBTreeMultiComparator(), rTreeAccessors,
-                bTreeAccessors, searcherRefCount, includeMemComponent, lsmHarness, comparatorFields, linearizerArray, ctx.searchCallback);
+                bTreeAccessors, searcherRefCount, includeMemComponent, lsmHarness, comparatorFields, linearizerArray,
+                ctx.searchCallback);
         cursor.open(initialState, pred);
     }
 
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 f83ac35..eb79c3a 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
@@ -43,8 +43,10 @@
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFileManager;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 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.freepage.InMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMTreeIndexAccessor;
@@ -71,11 +73,12 @@
             ILSMFileManager fileManager, RTreeFactory diskRTreeFactory, RTreeFactory bulkLoadRTreeFactory,
             IFileMapProvider diskFileMapProvider, int fieldCount, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, ILinearizeComparatorFactory linearizer,
-            int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, ILSMFlushPolicy flushPolicy, ILSMMergePolicy mergePolicy) {
+            int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, ILSMFlushController flushController,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) {
         super(memBufferCache, memFreePageManager, rtreeInteriorFrameFactory, rtreeLeafFrameFactory,
                 btreeInteriorFrameFactory, btreeLeafFrameFactory, fileManager, diskRTreeFactory, diskFileMapProvider,
                 new TreeIndexComponentFinalizer(diskFileMapProvider), fieldCount, rtreeCmpFactories, btreeCmpFactories,
-                linearizer, comparatorFields, linearizerArray, flushPolicy, mergePolicy);
+                linearizer, comparatorFields, linearizerArray, flushController, mergePolicy, opTracker, ioScheduler);
         this.bulkLoadRTreeFactory = bulkLoadRTreeFactory;
 
     }
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 bf20bbc..f4680f9 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
@@ -30,8 +30,10 @@
 import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.freepage.LinkedListFreePageManagerFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFileManager;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushPolicy;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 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.freepage.InMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BTreeFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMTreeFileManager;
@@ -56,8 +58,8 @@
             IIOManager ioManager, String onDiskDir, IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider,
             ITypeTraits[] typeTraits, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, IPrimitiveValueProviderFactory[] valueProviderFactories,
-            RTreePolicyType rtreePolicyType, ILSMFlushPolicy flushPolicy,
-            ILSMMergePolicy mergePolicy) throws TreeIndexException {
+            RTreePolicyType rtreePolicyType, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) throws TreeIndexException {
         LSMTypeAwareTupleWriterFactory rtreeTupleWriterFactory = new LSMTypeAwareTupleWriterFactory(typeTraits, false);
         LSMTypeAwareTupleWriterFactory btreeTupleWriterFactory = new LSMTypeAwareTupleWriterFactory(typeTraits, true);
 
@@ -76,8 +78,8 @@
         RTreeFactory diskRTreeFactory = new RTreeFactory(diskBufferCache, freePageManagerFactory, rtreeCmpFactories,
                 typeTraits.length, rtreeInteriorFrameFactory, rtreeLeafFrameFactory);
         // TODO: Do we need another operation callback here?
-        BTreeFactory diskBTreeFactory = new BTreeFactory(diskBufferCache, freePageManagerFactory,
-                btreeCmpFactories, typeTraits.length, btreeInteriorFrameFactory, btreeLeafFrameFactory);
+        BTreeFactory diskBTreeFactory = new BTreeFactory(diskBufferCache, freePageManagerFactory, btreeCmpFactories,
+                typeTraits.length, btreeInteriorFrameFactory, btreeLeafFrameFactory);
 
         ILinearizeComparatorFactory linearizer = proposeBestLinearizer(typeTraits, rtreeCmpFactories.length);
         int[] comparatorFields = { 0 };
@@ -87,7 +89,8 @@
         LSMRTree lsmTree = new LSMRTree(memBufferCache, memFreePageManager, rtreeInteriorFrameFactory,
                 rtreeLeafFrameFactory, btreeInteriorFrameFactory, btreeLeafFrameFactory, fileNameManager,
                 diskRTreeFactory, diskBTreeFactory, diskFileMapProvider, typeTraits.length, rtreeCmpFactories,
-                btreeCmpFactories, linearizer, comparatorFields, linearizerArray, flushPolicy, mergePolicy);
+                btreeCmpFactories, linearizer, comparatorFields, linearizerArray, flushController, mergePolicy, opTracker,
+                ioScheduler);
         return lsmTree;
     }
 
@@ -96,8 +99,8 @@
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMFlushPolicy flushPolicy, ILSMMergePolicy mergePolicy)
-            throws TreeIndexException {
+            ILSMFlushController flushPolicy, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMIOScheduler ioScheduler) throws TreeIndexException {
 
         LSMRTreeTupleWriterFactory rtreeTupleWriterFactory = new LSMRTreeTupleWriterFactory(typeTraits, false);
         LSMRTreeTupleWriterFactory btreeTupleWriterFactory = new LSMRTreeTupleWriterFactory(typeTraits, true);
@@ -135,7 +138,8 @@
         LSMRTreeWithAntiMatterTuples lsmTree = new LSMRTreeWithAntiMatterTuples(memBufferCache, memFreePageManager,
                 rtreeInteriorFrameFactory, rtreeLeafFrameFactory, btreeInteriorFrameFactory, btreeLeafFrameFactory,
                 fileNameManager, diskRTreeFactory, bulkLoadRTreeFactory, diskFileMapProvider, typeTraits.length,
-                rtreeCmpFactories, btreeCmpFactories, linearizer, comparatorFields, linearizerArray, flushPolicy, mergePolicy);
+                rtreeCmpFactories, btreeCmpFactories, linearizer, comparatorFields, linearizerArray, flushPolicy,
+                mergePolicy, opTracker, ioScheduler);
         return lsmTree;
     }
 
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 3615241..acce282 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
@@ -28,7 +28,6 @@
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestContext;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestHarness;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 
 @SuppressWarnings("rawtypes")
 public class LSMBTreeBulkLoadTest extends OrderedIndexBulkLoadTest {
@@ -54,7 +53,9 @@
             BTreeLeafFrameType leafType) throws Exception {
         return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFileId(), NoMergePolicy.INSTANCE);
+                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFileId(),
+                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTracker(),
+                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 f06f563..771696b 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
@@ -28,7 +28,6 @@
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestContext;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestHarness;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 
 @SuppressWarnings("rawtypes")
 public class LSMBTreeDeleteTest extends OrderedIndexDeleteTest {
@@ -54,7 +53,9 @@
             BTreeLeafFrameType leafType) throws Exception {
         return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFileId(), NoMergePolicy.INSTANCE);
+                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFileId(),
+                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTracker(),
+                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 8ebe248..a6544e3 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
@@ -27,8 +27,6 @@
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 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.impls.ImmediateFlushPolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 
 public class LSMBTreeExamplesTest extends OrderedIndexExamplesTest {
     private final LSMBTreeTestHarness harness = new LSMBTreeTestHarness();
@@ -38,8 +36,8 @@
             throws TreeIndexException {
         return LSMBTreeUtils.createLSMTree(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), typeTraits, cmpFactories, new ImmediateFlushPolicy(harness.getIOScheduler()),
-                NoMergePolicy.INSTANCE);
+                harness.getDiskFileMapProvider(), typeTraits, cmpFactories, harness.getFlushController(),
+                harness.getMergePolicy(), harness.getOperationTracker(), 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/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 f697b8e..15fbfa1 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
@@ -28,7 +28,6 @@
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestContext;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestHarness;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 
 @SuppressWarnings("rawtypes")
 public class LSMBTreeInsertTest extends OrderedIndexInsertTest {
@@ -54,7 +53,9 @@
             BTreeLeafFrameType leafType) throws Exception {
         return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFileId(), NoMergePolicy.INSTANCE);
+                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFileId(),
+                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTracker(),
+                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/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 0b0cb2f..d2d3bd9 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
@@ -27,7 +27,6 @@
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestContext;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestHarness;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 
 @SuppressWarnings("rawtypes")
 public class LSMBTreeMergeTest extends LSMBTreeMergeTestDriver {
@@ -53,7 +52,9 @@
             BTreeLeafFrameType leafType) throws Exception {
         return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFileId(), NoMergePolicy.INSTANCE);
+                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFileId(),
+                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTracker(),
+                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 1237653..9219676 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
@@ -29,7 +29,6 @@
 import edu.uci.ics.hyracks.storage.am.config.AccessMethodTestsConfig;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestContext;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestHarness;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 
 @SuppressWarnings("rawtypes")
 public class LSMBTreeMultiBulkLoadTest extends OrderedIndexBulkLoadTest {
@@ -55,7 +54,9 @@
             BTreeLeafFrameType leafType) throws Exception {
         return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFileId(), NoMergePolicy.INSTANCE);
+                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFileId(),
+                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTracker(),
+                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 513c1d1..bdefe39 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
@@ -28,7 +28,6 @@
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestContext;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestHarness;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 
 @SuppressWarnings("rawtypes")
 public class LSMBTreeUpdateTest extends OrderedIndexUpdateTest {
@@ -54,7 +53,9 @@
             BTreeLeafFrameType leafType) throws Exception {
         return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFileId(), NoMergePolicy.INSTANCE);
+                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getFileId(),
+                harness.getFlushController(), harness.getMergePolicy(), harness.getOperationTracker(),
+                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 81fa29c..394ffe9 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
@@ -29,8 +29,6 @@
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 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.impls.ImmediateFlushPolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 
 public class LSMBTreeMultiThreadTest extends OrderedIndexMultiThreadTest {
 
@@ -53,8 +51,8 @@
             throws TreeIndexException {
         return LSMBTreeUtils.createLSMTree(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), typeTraits, cmpFactories, new ImmediateFlushPolicy(harness.getIOScheduler()),
-                NoMergePolicy.INSTANCE);
+                harness.getDiskFileMapProvider(), typeTraits, cmpFactories, harness.getFlushController(),
+                harness.getMergePolicy(), harness.getOperationTracker(), 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 38c52ed..62d9115 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
@@ -32,11 +32,13 @@
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.impls.LSMBTree;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeUtils;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 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.ImmediateFlushPolicy;
+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.SequentialScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.RefCountingOperationTracker;
 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;
@@ -60,6 +62,7 @@
 
     protected final int numBatches;
     protected final LSMBTree lsmtree;
+    protected final ILSMIOScheduler ioScheduler;
     protected IBufferCache memBufferCache;
     private final int onDiskPageSize;
     private final int onDiskNumPages;
@@ -83,10 +86,10 @@
                 inMemNumPages);
         InMemoryFreePageManager memFreePageManager = new InMemoryFreePageManager(inMemNumPages,
                 new LIFOMetaDataFrameFactory());
-
+        this.ioScheduler = ImmediateScheduler.INSTANCE;
         lsmtree = LSMBTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ioManager, onDiskDir, bufferCache,
-                fmp, typeTraits, cmpFactories, new ImmediateFlushPolicy(SequentialScheduler.INSTANCE),
-                NoMergePolicy.INSTANCE);
+                fmp, typeTraits, cmpFactories, new FlushController(), NoMergePolicy.INSTANCE,
+                new RefCountingOperationTracker(), ioScheduler);
     }
 
     @Override
@@ -124,6 +127,7 @@
 
     @Override
     public void deinit() throws Exception {
+        ioScheduler.shutdown();
         bufferCache.closeFile(lsmtreeFileId);
         bufferCache.close();
         memBufferCache.closeFile(lsmtreeFileId);
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 fcc6245..8d5c94d 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
@@ -26,11 +26,12 @@
 import edu.uci.ics.hyracks.storage.am.common.CheckTuple;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.impls.LSMBTree;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 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.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateFlushPolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.SequentialScheduler;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
@@ -64,12 +65,13 @@
     public static LSMBTreeTestContext create(InMemoryBufferCache memBufferCache,
             InMemoryFreePageManager memFreePageManager, IOManager ioManager, String onDiskDir,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
-            int numKeyFields, int fileId, ILSMMergePolicy mergePolicy) throws Exception {
+            int numKeyFields, int fileId, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] cmpFactories = SerdeUtils.serdesToComparatorFactories(fieldSerdes, numKeyFields);
-        LSMBTree lsmTree = LSMBTreeUtils.createLSMTree(memBufferCache, memFreePageManager,
-                ioManager, onDiskDir, diskBufferCache, diskFileMapProvider, typeTraits, cmpFactories,
-                new ImmediateFlushPolicy(SequentialScheduler.INSTANCE), mergePolicy);
+        LSMBTree lsmTree = LSMBTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ioManager, onDiskDir,
+                diskBufferCache, diskFileMapProvider, typeTraits, cmpFactories, flushController, mergePolicy,
+                opTracker, ioScheduler);
         lsmTree.create(fileId);
         lsmTree.open(fileId);
         LSMBTreeTestContext testCtx = new LSMBTreeTestContext(fieldSerdes, lsmTree);
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 d2f25bc..b05ded0 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
@@ -30,10 +30,16 @@
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
 import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.config.AccessMethodTestsConfig;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+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.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.SequentialScheduler;
+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.RefCountingOperationTracker;
 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;
@@ -62,6 +68,9 @@
     protected InMemoryFreePageManager memFreePageManager;
     protected IHyracksTaskContext ctx;
     protected ILSMIOScheduler ioScheduler;
+    protected ILSMFlushController flushController;
+    protected ILSMMergePolicy mergePolicy;
+    protected ILSMOperationTracker opTracker;
 
     protected final Random rnd = new Random();
     protected final static SimpleDateFormat simpleDateFormat = new SimpleDateFormat("ddMMyy-hhmmssSS");
@@ -69,13 +78,16 @@
     protected String onDiskDir;
 
     public LSMBTreeTestHarness() {
-    	this.diskPageSize = AccessMethodTestsConfig.LSM_BTREE_DISK_PAGE_SIZE;
-    	this.diskNumPages = AccessMethodTestsConfig.LSM_BTREE_DISK_NUM_PAGES;
-    	this.diskMaxOpenFiles = AccessMethodTestsConfig.LSM_BTREE_DISK_MAX_OPEN_FILES;
-    	this.memPageSize = AccessMethodTestsConfig.LSM_BTREE_MEM_PAGE_SIZE;
-    	this.memNumPages = AccessMethodTestsConfig.LSM_BTREE_MEM_NUM_PAGES;
-    	this.hyracksFrameSize = AccessMethodTestsConfig.LSM_BTREE_HYRACKS_FRAME_SIZE;
-    	this.ioScheduler = SequentialScheduler.INSTANCE;
+        this.diskPageSize = AccessMethodTestsConfig.LSM_BTREE_DISK_PAGE_SIZE;
+        this.diskNumPages = AccessMethodTestsConfig.LSM_BTREE_DISK_NUM_PAGES;
+        this.diskMaxOpenFiles = AccessMethodTestsConfig.LSM_BTREE_DISK_MAX_OPEN_FILES;
+        this.memPageSize = AccessMethodTestsConfig.LSM_BTREE_MEM_PAGE_SIZE;
+        this.memNumPages = AccessMethodTestsConfig.LSM_BTREE_MEM_NUM_PAGES;
+        this.hyracksFrameSize = AccessMethodTestsConfig.LSM_BTREE_HYRACKS_FRAME_SIZE;
+        this.ioScheduler = ImmediateScheduler.INSTANCE;
+        this.mergePolicy = NoMergePolicy.INSTANCE;
+        this.flushController = new FlushController();
+        this.opTracker = new RefCountingOperationTracker();
     }
 
     public LSMBTreeTestHarness(int diskPageSize, int diskNumPages, int diskMaxOpenFiles, int memPageSize,
@@ -86,7 +98,10 @@
         this.memPageSize = memPageSize;
         this.memNumPages = memNumPages;
         this.hyracksFrameSize = hyracksFrameSize;
-        this.ioScheduler = SequentialScheduler.INSTANCE;
+        this.ioScheduler = ImmediateScheduler.INSTANCE;
+        this.mergePolicy = NoMergePolicy.INSTANCE;
+        this.flushController = new FlushController();
+        this.opTracker = new RefCountingOperationTracker();
     }
 
     public void setUp() throws HyracksException {
@@ -102,6 +117,7 @@
     }
 
     public void tearDown() throws HyracksDataException {
+        ioScheduler.shutdown();
         diskBufferCache.close();
         for (IODeviceHandle dev : ioManager.getIODevices()) {
             File dir = new File(dev.getPath(), onDiskDir);
@@ -184,4 +200,16 @@
     public ILSMIOScheduler getIOScheduler() {
         return ioScheduler;
     }
+
+    public ILSMOperationTracker getOperationTracker() {
+        return opTracker;
+    }
+
+    public ILSMFlushController getFlushController() {
+        return flushController;
+    }
+
+    public ILSMMergePolicy getMergePolicy() {
+        return mergePolicy;
+    }
 }
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 288bccd..0ecd7da 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
@@ -24,7 +24,6 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestContext;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeBulkLoadTest;
@@ -57,7 +56,8 @@
         return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
-                harness.getFileId(), NoMergePolicy.INSTANCE);
+                harness.getFileId(), harness.getFlushController(), harness.getMergePolicy(),
+                harness.getOperationTracker(), 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/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 9c31b48..4202fcd 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
@@ -24,7 +24,6 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestContext;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeDeleteTest;
@@ -53,7 +52,8 @@
         return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
-                harness.getFileId(), NoMergePolicy.INSTANCE);
+                harness.getFileId(), harness.getFlushController(), harness.getMergePolicy(),
+                harness.getOperationTracker(), 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/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 888e794..8cb9172 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
@@ -25,8 +25,6 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateFlushPolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.utils.LSMRTreeUtils;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeExamplesTest;
@@ -42,8 +40,8 @@
         return LSMRTreeUtils.createLSMTree(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), typeTraits, rtreeCmpFactories, btreeCmpFactories,
-                valueProviderFactories, rtreePolicyType, new ImmediateFlushPolicy(harness.getIOScheduler()),
-                NoMergePolicy.INSTANCE);
+                valueProviderFactories, rtreePolicyType, harness.getFlushController(), harness.getMergePolicy(),
+                harness.getOperationTracker(), 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/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 639a926..6b9fe6d 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
@@ -24,7 +24,6 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestContext;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeInsertTest;
@@ -53,7 +52,8 @@
         return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
-                harness.getFileId(), NoMergePolicy.INSTANCE);
+                harness.getFileId(), harness.getFlushController(), harness.getMergePolicy(),
+                harness.getOperationTracker(), 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/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 8ddf58c..06fa2f9 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
@@ -24,7 +24,6 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestContext;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeTestContext;
@@ -52,7 +51,8 @@
         return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
-                harness.getFileId(), NoMergePolicy.INSTANCE);
+                harness.getFileId(), harness.getFlushController(), harness.getMergePolicy(),
+                harness.getOperationTracker(), 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/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 e3dce3d..2d84e8f 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
@@ -25,7 +25,6 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.config.AccessMethodTestsConfig;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestContext;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeBulkLoadTest;
@@ -57,7 +56,8 @@
         return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
-                harness.getFileId(), NoMergePolicy.INSTANCE);
+                harness.getFileId(), harness.getFlushController(), harness.getMergePolicy(),
+                harness.getOperationTracker(), 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/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 2f23ccf..b1bc1a3 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
@@ -24,7 +24,6 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeWithAntiMatterTuplesTestContext;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeBulkLoadTest;
@@ -57,7 +56,8 @@
         return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getMemBufferCache(),
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getOnDiskDir(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
-                numKeys, rtreePolicyType, harness.getFileId(), NoMergePolicy.INSTANCE);
+                numKeys, rtreePolicyType, harness.getFileId(), harness.getFlushController(), harness.getMergePolicy(),
+                harness.getOperationTracker(), 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 b830317..04b7ea6 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
@@ -24,7 +24,6 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeWithAntiMatterTuplesTestContext;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeDeleteTest;
@@ -53,7 +52,8 @@
         return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getMemBufferCache(),
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getOnDiskDir(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
-                numKeys, rtreePolicyType, harness.getFileId(), NoMergePolicy.INSTANCE);
+                numKeys, rtreePolicyType, harness.getFileId(), harness.getFlushController(), harness.getMergePolicy(),
+                harness.getOperationTracker(), 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 a972228..8c13a00 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
@@ -25,8 +25,6 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateFlushPolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.utils.LSMRTreeUtils;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeExamplesTest;
@@ -42,8 +40,8 @@
         return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(harness.getMemBufferCache(),
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getOnDiskDir(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits, rtreeCmpFactories,
-                btreeCmpFactories, valueProviderFactories, rtreePolicyType,
-                new ImmediateFlushPolicy(harness.getIOScheduler()), NoMergePolicy.INSTANCE);
+                btreeCmpFactories, valueProviderFactories, rtreePolicyType, harness.getFlushController(),
+                harness.getMergePolicy(), harness.getOperationTracker(), 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/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 8468ed3..e938109 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
@@ -24,7 +24,6 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeWithAntiMatterTuplesTestContext;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeInsertTest;
@@ -53,7 +52,8 @@
         return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getMemBufferCache(),
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getOnDiskDir(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
-                numKeys, rtreePolicyType, harness.getFileId(), NoMergePolicy.INSTANCE);
+                numKeys, rtreePolicyType, harness.getFileId(), harness.getFlushController(), harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler());
 
     }
 
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 4d1ffd4..9350679 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
@@ -24,7 +24,6 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeWithAntiMatterTuplesTestContext;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeTestContext;
@@ -52,7 +51,8 @@
         return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getMemBufferCache(),
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getOnDiskDir(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
-                numKeys, rtreePolicyType, harness.getFileId(), NoMergePolicy.INSTANCE);
+                numKeys, rtreePolicyType, harness.getFileId(), harness.getFlushController(), harness.getMergePolicy(),
+                harness.getOperationTracker(), 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 cfb4bc7..20d1ef1 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
@@ -25,7 +25,6 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksException;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.config.AccessMethodTestsConfig;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeWithAntiMatterTuplesTestContext;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeBulkLoadTest;
@@ -57,7 +56,8 @@
         return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getMemBufferCache(),
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getOnDiskDir(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
-                numKeys, rtreePolicyType, harness.getFileId(), NoMergePolicy.INSTANCE);
+                numKeys, rtreePolicyType, harness.getFileId(), harness.getFlushController(), harness.getMergePolicy(),
+                harness.getOperationTracker(), 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 710076a..1a8779d 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
@@ -27,8 +27,6 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateFlushPolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.utils.LSMRTreeUtils;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeMultiThreadTest;
@@ -57,8 +55,8 @@
         return LSMRTreeUtils.createLSMTree(harness.getMemBufferCache(), harness.getMemFreePageManager(),
                 harness.getIOManager(), harness.getOnDiskDir(), harness.getDiskBufferCache(),
                 harness.getDiskFileMapProvider(), typeTraits, rtreeCmpFactories, btreeCmpFactories,
-                valueProviderFactories, rtreePolicyType, new ImmediateFlushPolicy(harness.getIOScheduler()),
-                NoMergePolicy.INSTANCE);
+                valueProviderFactories, rtreePolicyType, harness.getFlushController(), harness.getMergePolicy(),
+                harness.getOperationTracker(), 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/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 f0211d8..8616946 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
@@ -27,8 +27,6 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateFlushPolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.util.LSMRTreeTestHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.utils.LSMRTreeUtils;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeMultiThreadTest;
@@ -57,8 +55,8 @@
         return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(harness.getMemBufferCache(),
                 harness.getMemFreePageManager(), harness.getIOManager(), harness.getOnDiskDir(),
                 harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits, rtreeCmpFactories,
-                btreeCmpFactories, valueProviderFactories, rtreePolicyType, new ImmediateFlushPolicy(harness.getIOScheduler()),
-                NoMergePolicy.INSTANCE);
+                btreeCmpFactories, valueProviderFactories, rtreePolicyType, harness.getFlushController(),
+                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler());
 
     }
 
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 fbedc6a..2bbff9e 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
@@ -24,11 +24,12 @@
 import edu.uci.ics.hyracks.dataflow.common.util.SerdeUtils;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 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.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateFlushPolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.SequentialScheduler;
 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;
@@ -69,7 +70,8 @@
             InMemoryFreePageManager memFreePageManager, IOManager ioManager, String onDiskDir,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeyFields, RTreePolicyType rtreePolicyType,
-            int fileId, ILSMMergePolicy mergePolicy) throws Exception {
+            int fileId, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] rtreeCmpFactories = SerdeUtils
                 .serdesToComparatorFactories(fieldSerdes, numKeyFields);
@@ -77,8 +79,7 @@
                 fieldSerdes.length);
         LSMRTree lsmTree = LSMRTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ioManager, onDiskDir,
                 diskBufferCache, diskFileMapProvider, typeTraits, rtreeCmpFactories, btreeCmpFactories,
-                valueProviderFactories, rtreePolicyType, new ImmediateFlushPolicy(SequentialScheduler.INSTANCE),
-                mergePolicy);
+                valueProviderFactories, rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler);
         lsmTree.create(fileId);
         lsmTree.open(fileId);
         LSMRTreeTestContext testCtx = new LSMRTreeTestContext(fieldSerdes, lsmTree);
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 2c4432d..405f791 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
@@ -29,10 +29,16 @@
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
 import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.config.AccessMethodTestsConfig;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+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.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.SequentialScheduler;
+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.RefCountingOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.impls.LSMRTreeInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.impls.LSMRTreeInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
@@ -61,6 +67,9 @@
     protected LSMRTreeInMemoryFreePageManager memFreePageManager;
     protected IHyracksTaskContext ctx;
     protected ILSMIOScheduler ioScheduler;
+    protected ILSMFlushController flushController;
+    protected ILSMMergePolicy mergePolicy;
+    protected ILSMOperationTracker opTracker;
 
     protected final Random rnd = new Random();
     protected final static SimpleDateFormat simpleDateFormat = new SimpleDateFormat("ddMMyy-hhmmssSS");
@@ -74,7 +83,10 @@
         this.memPageSize = AccessMethodTestsConfig.LSM_RTREE_MEM_PAGE_SIZE;
         this.memNumPages = AccessMethodTestsConfig.LSM_RTREE_MEM_NUM_PAGES;
         this.hyracksFrameSize = AccessMethodTestsConfig.LSM_RTREE_HYRACKS_FRAME_SIZE;
-        this.ioScheduler = SequentialScheduler.INSTANCE;
+        this.ioScheduler = ImmediateScheduler.INSTANCE;
+        this.mergePolicy = NoMergePolicy.INSTANCE;
+        this.flushController = new FlushController();
+        this.opTracker = new RefCountingOperationTracker();
     }
 
     public LSMRTreeTestHarness(int diskPageSize, int diskNumPages, int diskMaxOpenFiles, int memPageSize,
@@ -85,7 +97,10 @@
         this.memPageSize = memPageSize;
         this.memNumPages = memNumPages;
         this.hyracksFrameSize = hyracksFrameSize;
-        this.ioScheduler = SequentialScheduler.INSTANCE;
+        this.ioScheduler = ImmediateScheduler.INSTANCE;
+        this.mergePolicy = NoMergePolicy.INSTANCE;
+        this.flushController = new FlushController();
+        this.opTracker = new RefCountingOperationTracker();
     }
 
     public void setUp() throws HyracksException {
@@ -101,6 +116,7 @@
     }
 
     public void tearDown() throws HyracksDataException {
+        ioScheduler.shutdown();
         diskBufferCache.close();
         for (IODeviceHandle dev : ioManager.getIODevices()) {
             File dir = new File(dev.getPath(), onDiskDir);
@@ -183,4 +199,16 @@
     public ILSMIOScheduler getIOScheduler() {
         return ioScheduler;
     }
+
+    public ILSMOperationTracker getOperationTracker() {
+        return opTracker;
+    }
+
+    public ILSMFlushController getFlushController() {
+        return flushController;
+    }
+
+    public ILSMMergePolicy getMergePolicy() {
+        return mergePolicy;
+    }
 }
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 410adca..4b2e010 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
@@ -24,11 +24,12 @@
 import edu.uci.ics.hyracks.dataflow.common.util.SerdeUtils;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMFlushController;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
 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.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ImmediateFlushPolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.SequentialScheduler;
 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;
@@ -69,7 +70,8 @@
             InMemoryFreePageManager memFreePageManager, IOManager ioManager, String onDiskDir,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeyFields, RTreePolicyType rtreePolicyType,
-            int fileId, ILSMMergePolicy mergePolicy) throws Exception {
+            int fileId, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
+            ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] rtreeCmpFactories = SerdeUtils
                 .serdesToComparatorFactories(fieldSerdes, numKeyFields);
@@ -77,8 +79,8 @@
                 fieldSerdes.length);
         LSMRTreeWithAntiMatterTuples lsmTree = LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(memBufferCache,
                 memFreePageManager, ioManager, onDiskDir, diskBufferCache, diskFileMapProvider, typeTraits,
-                rtreeCmpFactories, btreeCmpFactories, valueProviderFactories, rtreePolicyType, new ImmediateFlushPolicy(SequentialScheduler.INSTANCE),
-                mergePolicy);
+                rtreeCmpFactories, btreeCmpFactories, valueProviderFactories, rtreePolicyType, flushController,
+                mergePolicy, opTracker, ioScheduler);
         lsmTree.create(fileId);
         lsmTree.open(fileId);
         LSMRTreeWithAntiMatterTuplesTestContext testCtx = new LSMRTreeWithAntiMatterTuplesTestContext(fieldSerdes,