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 d0786e9..25b8b8c 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
@@ -24,7 +24,7 @@
 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.ILSMFlushController;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
@@ -42,18 +42,18 @@
     private final ILSMFlushController flushController;
     private final ILSMMergePolicy mergePolicy;
     private final ILSMOperationTracker opTracker;
-    private final ILSMIOScheduler ioScheduler;
+    private final ILSMIOOperationScheduler ioScheduler;
 
     public LSMBTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
             ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOScheduler ioScheduler) {
+            ILSMIOOperationScheduler 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, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
-            ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) {
+            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) {
         super(opDesc, ctx, partition);
         this.memPageSize = memPageSize;
         this.memNumPages = memNumPages;
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 8e80198..6b5f07a 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
@@ -52,7 +52,7 @@
 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.ILSMFlushController;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 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;
@@ -103,7 +103,7 @@
             TreeFactory<BTree> diskBTreeFactory, TreeFactory<BTree> bulkLoadBTreeFactory,
             IFileMapProvider diskFileMapProvider, int fieldCount, IBinaryComparatorFactory[] cmpFactories,
             ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOScheduler ioScheduler) {
+            ILSMIOOperationScheduler ioScheduler) {
         memBTree = new BTree(memBufferCache, ((InMemoryBufferCache) memBufferCache).getFileMapProvider(),
                 memFreePageManager, interiorFrameFactory, insertLeafFrameFactory, cmpFactories, fieldCount,
                 memBtreeFile);
@@ -542,7 +542,7 @@
     }
 
     @Override
-    public ILSMIOScheduler getIOScheduler() {
+    public ILSMIOOperationScheduler 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 626cd6f..3b535f4 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
@@ -32,7 +32,7 @@
 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.ILSMFlushController;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
@@ -48,7 +48,7 @@
             InMemoryFreePageManager memFreePageManager, IIOManager ioManager, FileReference file,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
             IBinaryComparatorFactory[] cmpFactories, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
-            ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) {
+            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) {
         LSMBTreeTupleWriterFactory insertTupleWriterFactory = new LSMBTreeTupleWriterFactory(typeTraits,
                 cmpFactories.length, false);
         LSMBTreeTupleWriterFactory deleteTupleWriterFactory = new LSMBTreeTupleWriterFactory(typeTraits,
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 0698295..94f53a4 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
@@ -65,5 +65,5 @@
 
     public ILSMOperationTracker getOperationTracker();
 
-    public ILSMIOScheduler getIOScheduler();
+    public ILSMIOOperationScheduler getIOScheduler();
 }
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperation.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperation.java
new file mode 100644
index 0000000..459b0d9
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperation.java
@@ -0,0 +1,17 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.util.List;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.io.IODeviceHandle;
+import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
+
+public interface ILSMIOOperation {
+    public List<IODeviceHandle> getReadDevices();
+
+    public List<IODeviceHandle> getWriteDevices();
+
+    public void perform() throws HyracksDataException, IndexException;
+
+    public ILSMIOOperationCallback getCallback();
+}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallback.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallback.java
new file mode 100644
index 0000000..edc9b4d
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationCallback.java
@@ -0,0 +1,5 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+public interface ILSMIOOperationCallback {
+    public void callback();
+}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationScheduler.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationScheduler.java
new file mode 100644
index 0000000..fe81203
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOOperationScheduler.java
@@ -0,0 +1,6 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+
+public interface ILSMIOOperationScheduler {
+    public void scheduleOperation(ILSMIOOperation operation);
+}
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
deleted file mode 100644
index 6929232..0000000
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOScheduler.java
+++ /dev/null
@@ -1,9 +0,0 @@
-package edu.uci.ics.hyracks.storage.am.lsm.common.api;
-
-public interface ILSMIOScheduler {
-    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/ILSMIOSchedulerProvider.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOSchedulerProvider.java
index c1e8ecb..d56d163 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOSchedulerProvider.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIOSchedulerProvider.java
@@ -3,5 +3,5 @@
 import java.io.Serializable;
 
 public interface ILSMIOSchedulerProvider extends Serializable {
-    public ILSMIOScheduler getIOScheduler();
+    public ILSMIOOperationScheduler getIOScheduler();
 }
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 f934ed1..95dea2f 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
@@ -65,5 +65,5 @@
 
     public ILSMOperationTracker getOperationTracker();
 
-    public ILSMIOScheduler getIOScheduler();
+    public ILSMIOOperationScheduler getIOScheduler();
 }
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java
index cff8d9b..1f63cd3 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ConstantMergePolicy.java
@@ -1,16 +1,16 @@
 package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
 
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 
 public class ConstantMergePolicy implements ILSMMergePolicy {
 
-    private final ILSMIOScheduler ioScheduler;
+    private final ILSMIOOperationScheduler ioScheduler;
 
     private final int threshold;
 
-    public ConstantMergePolicy(ILSMIOScheduler ioScheduler, int threshold) {
+    public ConstantMergePolicy(ILSMIOOperationScheduler ioScheduler, int threshold) {
         this.ioScheduler = ioScheduler;
         this.threshold = threshold;
     }
@@ -18,7 +18,7 @@
     @Override
     public void diskComponentAdded(final ILSMIndex index, int totalNumDiskComponents) {
         if (totalNumDiskComponents >= threshold) {
-            ioScheduler.scheduleMerge(index);
+            ioScheduler.scheduleOperation(new LSMMergeOperation(index));
         }
     }
 }
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
index 7c76953..bd690ac 100644
--- 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
@@ -2,42 +2,23 @@
 
 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;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 
-public enum ImmediateScheduler implements ILSMIOScheduler {
+public enum ImmediateScheduler implements ILSMIOOperationScheduler {
     INSTANCE;
 
     @Override
-    public void scheduleFlush(final ILSMIndex index) {
+    public void scheduleOperation(ILSMIOOperation operation) {
         try {
-            ((ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE))
-                    .flush();
+            operation.perform();
         } catch (HyracksDataException e) {
             e.printStackTrace();
         } catch (IndexException e) {
             e.printStackTrace();
+        } finally {
+            operation.getCallback().callback();
         }
     }
 
-    @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/ImmediateSchedulerProvider.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateSchedulerProvider.java
index 3341059..2e27cc8 100644
--- a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateSchedulerProvider.java
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ImmediateSchedulerProvider.java
@@ -1,13 +1,13 @@
 package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
 
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOSchedulerProvider;
 
 public enum ImmediateSchedulerProvider implements ILSMIOSchedulerProvider {
     INSTANCE;
 
     @Override
-    public ILSMIOScheduler getIOScheduler() {
+    public ILSMIOOperationScheduler getIOScheduler() {
         return ImmediateScheduler.INSTANCE;
     }
 
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMFlushOperation.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMFlushOperation.java
new file mode 100644
index 0000000..1368899
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMFlushOperation.java
@@ -0,0 +1,46 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import java.util.Collections;
+import java.util.List;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.io.IODeviceHandle;
+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.ILSMIOOperation;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
+
+public class LSMFlushOperation implements ILSMIOOperation {
+
+    private final ILSMIndex index;
+
+    public LSMFlushOperation(ILSMIndex index) {
+        this.index = index;
+    }
+
+    @Override
+    public List<IODeviceHandle> getReadDevices() {
+        return Collections.emptyList();
+    }
+
+    @Override
+    public List<IODeviceHandle> getWriteDevices() {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public void perform() throws HyracksDataException, IndexException {
+        ILSMIndexAccessor accessor = (ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
+                NoOpOperationCallback.INSTANCE);
+        accessor.flush();
+    }
+
+    @Override
+    public ILSMIOOperationCallback getCallback() {
+        return NoOpIOOperationCallback.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 42d1277..2fe1093 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
@@ -29,7 +29,7 @@
 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.ILSMFlushController;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 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;
@@ -67,10 +67,10 @@
     private final ILSMFlushController flushController;
     private final ILSMMergePolicy mergePolicy;
     private final ILSMOperationTracker opTracker;
-    private final ILSMIOScheduler ioScheduler;
+    private final ILSMIOOperationScheduler ioScheduler;
 
     public LSMHarness(ILSMIndex lsmIndex, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
-            ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) {
+            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) {
         this.lsmIndex = lsmIndex;
         this.opTracker = opTracker;
         this.flushController = flushController;
@@ -243,7 +243,7 @@
         return opTracker;
     }
 
-    public ILSMIOScheduler getIOScheduler() {
+    public ILSMIOOperationScheduler getIOScheduler() {
         return ioScheduler;
     }
 }
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMMergeOperation.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMMergeOperation.java
new file mode 100644
index 0000000..2f82b7a
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMMergeOperation.java
@@ -0,0 +1,46 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import java.util.List;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.io.IODeviceHandle;
+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.ILSMIOOperation;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
+
+public class LSMMergeOperation implements ILSMIOOperation {
+
+    private final ILSMIndex index;
+
+    public LSMMergeOperation(ILSMIndex index) {
+        this.index = index;
+    }
+
+    @Override
+    public List<IODeviceHandle> getReadDevices() {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public List<IODeviceHandle> getWriteDevices() {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    @Override
+    public void perform() throws HyracksDataException, IndexException {
+        ILSMIndexAccessor accessor = (ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
+                NoOpOperationCallback.INSTANCE);
+        accessor.merge();
+    }
+
+    @Override
+    public ILSMIOOperationCallback getCallback() {
+        return NoOpIOOperationCallback.INSTANCE;
+    }
+
+}
diff --git a/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpIOOperationCallback.java b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpIOOperationCallback.java
new file mode 100644
index 0000000..1e51b41
--- /dev/null
+++ b/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpIOOperationCallback.java
@@ -0,0 +1,12 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
+
+public enum NoOpIOOperationCallback implements ILSMIOOperationCallback {
+    INSTANCE;
+
+    @Override
+    public void callback() {
+        // Do nothing.
+    }
+}
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
index aeb1227..12dc42d 100644
--- 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
@@ -28,15 +28,14 @@
     }
 
     @Override
-    public void threadExit(ILSMIndex index) {
+    public void threadExit(final 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);
+                index.getIOScheduler().scheduleOperation(new LSMFlushOperation(index));
             }
         }
     }
-
 }
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 b021300..c7396de 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
@@ -28,7 +28,7 @@
 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.ILSMFlushController;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
@@ -53,13 +53,13 @@
     protected final ILSMFlushController flushController;
     protected final ILSMMergePolicy mergePolicy;
     protected final ILSMOperationTracker opTracker;
-    protected final ILSMIOScheduler ioScheduler;
+    protected final ILSMIOOperationScheduler ioScheduler;
 
     public AbstractLSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
             IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOScheduler ioScheduler) {
+            ILSMIOOperationScheduler ioScheduler) {
         this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES, btreeComparatorFactories,
                 valueProviderFactories, rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler);
     }
@@ -68,7 +68,7 @@
             int memPageSize, int memNumPages, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOScheduler ioScheduler) {
+            ILSMIOOperationScheduler ioScheduler) {
         super(opDesc, ctx, partition);
         this.memPageSize = memPageSize;
         this.memNumPages = memNumPages;
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 4023dd2..39c431c 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
@@ -26,7 +26,7 @@
 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.ILSMFlushController;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
@@ -41,7 +41,7 @@
             IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOScheduler ioScheduler) {
+            ILSMIOOperationScheduler ioScheduler) {
         super(opDesc, ctx, partition, btreeComparatorFactories, valueProviderFactories, rtreePolicyType,
                 flushController, mergePolicy, opTracker, ioScheduler);
     }
@@ -50,7 +50,7 @@
             int memPageSize, int memNumPages, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOScheduler ioScheduler) {
+            ILSMIOOperationScheduler ioScheduler) {
         super(opDesc, ctx, partition, memPageSize, memNumPages, btreeComparatorFactories, valueProviderFactories,
                 rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler);
     }
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 d32e691..33aa669 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
@@ -26,7 +26,7 @@
 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.ILSMFlushController;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
@@ -40,7 +40,7 @@
             int partition, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOScheduler ioScheduler) {
+            ILSMIOOperationScheduler ioScheduler) {
         super(opDesc, ctx, partition, btreeComparatorFactories, valueProviderFactories, rtreePolicyType,
                 flushController, mergePolicy, opTracker, ioScheduler);
     }
@@ -49,7 +49,7 @@
             int partition, int memPageSize, int memNumPages, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOScheduler ioScheduler) {
+            ILSMIOOperationScheduler ioScheduler) {
         super(opDesc, ctx, partition, memPageSize, memNumPages, btreeComparatorFactories, valueProviderFactories,
                 rtreePolicyType, flushController, mergePolicy, opTracker, ioScheduler);
     }
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 862389e..076323e 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
@@ -40,7 +40,7 @@
 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.ILSMFlushController;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 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;
@@ -122,7 +122,7 @@
             ILSMComponentFinalizer componentFinalizer, int fieldCount, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, ILinearizeComparatorFactory linearizer,
             int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, ILSMFlushController flushController,
-            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) {
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) {
         RTree memRTree = new RTree(memBufferCache, ((InMemoryBufferCache) memBufferCache).getFileMapProvider(),
                 memFreePageManager, rtreeInteriorFrameFactory, rtreeLeafFrameFactory, rtreeCmpFactories, fieldCount,
                 memBtreeFile);
@@ -376,7 +376,7 @@
     }
 
     @Override
-    public ILSMIOScheduler getIOScheduler() {
+    public ILSMIOOperationScheduler 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 57dd07b..d6ba98f 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
@@ -43,7 +43,7 @@
 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.ILSMFlushController;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
@@ -71,7 +71,7 @@
             IFileMapProvider diskFileMapProvider, int fieldCount, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, ILinearizeComparatorFactory linearizer,
             int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, ILSMFlushController flushController,
-            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) {
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) {
         super(memBufferCache, memFreePageManager, rtreeInteriorFrameFactory, rtreeLeafFrameFactory,
                 btreeInteriorFrameFactory, btreeLeafFrameFactory, fileManager, diskRTreeFactory, diskFileMapProvider,
                 new LSMRTreeComponentFinalizer(diskFileMapProvider), fieldCount, rtreeCmpFactories, btreeCmpFactories,
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 9855ac2..9e1bdb3 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
@@ -44,7 +44,7 @@
 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.ILSMFlushController;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
@@ -75,7 +75,7 @@
             IFileMapProvider diskFileMapProvider, int fieldCount, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, ILinearizeComparatorFactory linearizer,
             int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, ILSMFlushController flushController,
-            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) {
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) {
         super(memBufferCache, memFreePageManager, rtreeInteriorFrameFactory, rtreeLeafFrameFactory,
                 btreeInteriorFrameFactory, btreeLeafFrameFactory, fileManager, diskRTreeFactory, diskFileMapProvider,
                 new TreeIndexComponentFinalizer(diskFileMapProvider), fieldCount, rtreeCmpFactories, btreeCmpFactories,
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 99c42e0..f49cc87 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
@@ -33,7 +33,7 @@
 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.ILSMFlushController;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOScheduler;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
@@ -64,7 +64,7 @@
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOScheduler ioScheduler) throws TreeIndexException {
+            ILSMIOOperationScheduler ioScheduler) throws TreeIndexException {
         LSMTypeAwareTupleWriterFactory rtreeTupleWriterFactory = new LSMTypeAwareTupleWriterFactory(typeTraits, false);
         LSMTypeAwareTupleWriterFactory btreeTupleWriterFactory = new LSMTypeAwareTupleWriterFactory(typeTraits, true);
 
@@ -107,7 +107,7 @@
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILSMFlushController flushPolicy, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOScheduler ioScheduler) throws TreeIndexException {
+            ILSMIOOperationScheduler ioScheduler) throws TreeIndexException {
 
         LSMRTreeTupleWriterFactory rtreeTupleWriterFactory = new LSMRTreeTupleWriterFactory(typeTraits, false);
         LSMRTreeTupleWriterFactory btreeTupleWriterFactory = new LSMRTreeTupleWriterFactory(typeTraits, true);
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 514f476..76c5967 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
@@ -34,7 +34,7 @@
 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.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.FlushController;
@@ -66,7 +66,7 @@
 
     protected final int numBatches;
     protected final LSMBTree lsmtree;
-    protected final ILSMIOScheduler ioScheduler;
+    protected final ILSMIOOperationScheduler ioScheduler;
     protected IBufferCache memBufferCache;
     private final int onDiskPageSize;
     private final int onDiskNumPages;
@@ -132,7 +132,6 @@
 
     @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 c552cd7..35ee472 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
@@ -28,7 +28,7 @@
 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.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
@@ -67,7 +67,7 @@
             InMemoryFreePageManager memFreePageManager, IOManager ioManager, FileReference file,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
             int numKeyFields, ILSMFlushController flushController, ILSMMergePolicy mergePolicy,
-            ILSMOperationTracker opTracker, ILSMIOScheduler ioScheduler) throws Exception {
+            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler) throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] cmpFactories = SerdeUtils.serdesToComparatorFactories(fieldSerdes, numKeyFields);
         LSMBTree lsmTree = LSMBTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ioManager, file,
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 e6a27f7..ab34e4b 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
@@ -32,7 +32,7 @@
 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.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
@@ -68,7 +68,7 @@
     protected InMemoryBufferCache memBufferCache;
     protected InMemoryFreePageManager memFreePageManager;
     protected IHyracksTaskContext ctx;
-    protected ILSMIOScheduler ioScheduler;
+    protected ILSMIOOperationScheduler ioScheduler;
     protected ILSMFlushController flushController;
     protected ILSMMergePolicy mergePolicy;
     protected ILSMOperationTracker opTracker;
@@ -121,7 +121,6 @@
     }
 
     public void tearDown() throws HyracksDataException {
-        ioScheduler.shutdown();
         diskBufferCache.close();
         for (IODeviceHandle dev : ioManager.getIODevices()) {
             File dir = new File(dev.getPath(), onDiskDir);
@@ -197,7 +196,7 @@
         return rnd;
     }
 
-    public ILSMIOScheduler getIOScheduler() {
+    public ILSMIOOperationScheduler getIOScheduler() {
         return ioScheduler;
     }
 
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 c9a0bc8..0ecc65e 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
@@ -26,7 +26,7 @@
 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.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
@@ -72,7 +72,7 @@
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeyFields, RTreePolicyType rtreePolicyType,
             ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOScheduler ioScheduler) throws Exception {
+            ILSMIOOperationScheduler ioScheduler) throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] rtreeCmpFactories = SerdeUtils
                 .serdesToComparatorFactories(fieldSerdes, numKeyFields);
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 0456879..8d60923 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
@@ -31,7 +31,7 @@
 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.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
@@ -67,7 +67,7 @@
     protected LSMRTreeInMemoryBufferCache memBufferCache;
     protected LSMRTreeInMemoryFreePageManager memFreePageManager;
     protected IHyracksTaskContext ctx;
-    protected ILSMIOScheduler ioScheduler;
+    protected ILSMIOOperationScheduler ioScheduler;
     protected ILSMFlushController flushController;
     protected ILSMMergePolicy mergePolicy;
     protected ILSMOperationTracker opTracker;
@@ -119,7 +119,6 @@
     }
 
     public void tearDown() throws HyracksDataException {
-        ioScheduler.shutdown();
         diskBufferCache.close();
         for (IODeviceHandle dev : ioManager.getIODevices()) {
             File dir = new File(dev.getPath(), onDiskDir);
@@ -199,7 +198,7 @@
         return rnd;
     }
 
-    public ILSMIOScheduler getIOScheduler() {
+    public ILSMIOOperationScheduler getIOScheduler() {
         return ioScheduler;
     }
 
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 20d9c83..14ad60d 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
@@ -26,7 +26,7 @@
 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.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
 import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
@@ -72,7 +72,7 @@
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeyFields, RTreePolicyType rtreePolicyType,
             ILSMFlushController flushController, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOScheduler ioScheduler) throws Exception {
+            ILSMIOOperationScheduler ioScheduler) throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] rtreeCmpFactories = SerdeUtils
                 .serdesToComparatorFactories(fieldSerdes, numKeyFields);