diff --git a/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/ConstantMergePolicy.java b/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/ConstantMergePolicy.java
index cf69bfe..dee652e 100644
--- a/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/ConstantMergePolicy.java
+++ b/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/ConstantMergePolicy.java
@@ -43,7 +43,7 @@
         if (!ctx.isShuttingdown() && immutableComponents.size() >= threshold) {
             ILSMIndexAccessor accessor = (ILSMIndexAccessor) index.createAccessor(NoOpOperationCallback.INSTANCE,
                     NoOpOperationCallback.INSTANCE);
-            accessor.scheduleMerge(NoOpIOOperationCallback.INSTANCE);
+            accessor.scheduleMerge(index.getIOOperationCallback());
         }
     }
 }
diff --git a/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/AbstractLSMIOOperationCallback.java b/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/AbstractLSMIOOperationCallback.java
index 4ebd921..684068b 100644
--- a/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/AbstractLSMIOOperationCallback.java
+++ b/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/AbstractLSMIOOperationCallback.java
@@ -22,6 +22,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallback;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMOperationType;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
 import edu.uci.ics.hyracks.storage.common.file.BufferedFileHandle;
@@ -30,19 +31,35 @@
 
     protected long firstLSN;
     protected long lastLSN;
+    protected long[] immutableLastLSNs;
+    protected int readIndex;
+    protected int writeIndex;
 
     public AbstractLSMIOOperationCallback() {
         resetLSNs();
     }
 
     @Override
-    public void beforeOperation() {
-        // Do nothing.
+    public void setNumOfMutableComponents(int count) {
+        immutableLastLSNs = new long[count];
+        readIndex = 0;
+        writeIndex = 0;
     }
 
     @Override
-    public void afterFinalize(ILSMComponent newComponent) {
-        resetLSNs();
+    public void beforeOperation(LSMOperationType opType) {
+        if (opType == LSMOperationType.FLUSH) {
+            synchronized (this) {
+                immutableLastLSNs[writeIndex] = lastLSN;
+                writeIndex = (writeIndex + 1) % immutableLastLSNs.length;
+                resetLSNs();
+            }
+        }
+    }
+
+    @Override
+    public void afterFinalize(LSMOperationType opType, ILSMComponent newComponent) {
+        // Do nothing.
     }
 
     public abstract long getComponentLSN(List<ILSMComponent> oldComponents) throws HyracksDataException;
@@ -85,18 +102,18 @@
         firstLSN = -1;
         lastLSN = -1;
     }
-    
+
     public void updateLastLSN(long lastLSN) {
         if (firstLSN == -1) {
             firstLSN = lastLSN;
         }
         this.lastLSN = Math.max(this.lastLSN, lastLSN);
     }
-    
+
     public long getFirstLSN() {
         return firstLSN;
     }
-    
+
     public long getLastLSN() {
         return lastLSN;
     }
diff --git a/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/LSMBTreeIOOperationCallback.java b/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/LSMBTreeIOOperationCallback.java
index 87c497c..8e9b44e 100644
--- a/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/LSMBTreeIOOperationCallback.java
+++ b/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/LSMBTreeIOOperationCallback.java
@@ -21,6 +21,7 @@
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.impls.LSMBTreeDiskComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMOperationType;
 
 public class LSMBTreeIOOperationCallback extends AbstractLSMIOOperationCallback {
 
@@ -29,7 +30,7 @@
     }
 
     @Override
-    public void afterOperation(List<ILSMComponent> oldComponents, ILSMComponent newComponent)
+    public void afterOperation(LSMOperationType opType, List<ILSMComponent> oldComponents, ILSMComponent newComponent)
             throws HyracksDataException {
         if (newComponent != null) {
             LSMBTreeDiskComponent btreeComponent = (LSMBTreeDiskComponent) newComponent;
@@ -41,7 +42,11 @@
     public long getComponentLSN(List<ILSMComponent> diskComponents) throws HyracksDataException {
         if (diskComponents == null) {
             // Implies a flush IO operation.
-            return lastLSN;
+            synchronized (this) {
+                long lsn = immutableLastLSNs[readIndex];
+                readIndex = (readIndex + 1) % immutableLastLSNs.length;
+                return lsn;
+            }
         }
         // Get max LSN from the diskComponents. Implies a merge IO operation or Recovery operation.
         long maxLSN = -1;
diff --git a/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/LSMInvertedIndexIOOperationCallback.java b/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/LSMInvertedIndexIOOperationCallback.java
index 60d4af1..5532f97 100644
--- a/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/LSMInvertedIndexIOOperationCallback.java
+++ b/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/LSMInvertedIndexIOOperationCallback.java
@@ -19,6 +19,7 @@
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMOperationType;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.impls.LSMInvertedIndexDiskComponent;
 
 public class LSMInvertedIndexIOOperationCallback extends AbstractLSMIOOperationCallback {
@@ -28,9 +29,9 @@
     }
 
     @Override
-    public void afterOperation(List<ILSMComponent> oldComponents, ILSMComponent newComponent)
+    public void afterOperation(LSMOperationType opType, List<ILSMComponent> oldComponents, ILSMComponent newComponent)
             throws HyracksDataException {
-        if (oldComponents != null && newComponent != null) {
+        if (newComponent != null) {
             LSMInvertedIndexDiskComponent invIndexComponent = (LSMInvertedIndexDiskComponent) newComponent;
             putLSNIntoMetadata(invIndexComponent.getDeletedKeysBTree(), oldComponents);
         }
@@ -40,7 +41,11 @@
     public long getComponentLSN(List<ILSMComponent> diskComponents) throws HyracksDataException {
         if (diskComponents == null) {
             // Implies a flush IO operation.
-            return lastLSN;
+            synchronized (this) {
+                long lsn = immutableLastLSNs[readIndex];
+                readIndex = (readIndex + 1) % immutableLastLSNs.length;
+                return lsn;
+            }
         }
         // Get max LSN from the diskComponents. Implies a merge IO operation or Recovery operation.
         long maxLSN = -1;
diff --git a/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/LSMRTreeIOOperationCallback.java b/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/LSMRTreeIOOperationCallback.java
index 770d514..1497e17 100644
--- a/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/LSMRTreeIOOperationCallback.java
+++ b/asterix-common/src/main/java/edu/uci/ics/asterix/common/ioopcallbacks/LSMRTreeIOOperationCallback.java
@@ -19,6 +19,7 @@
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMOperationType;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.impls.LSMRTreeDiskComponent;
 
 public class LSMRTreeIOOperationCallback extends AbstractLSMIOOperationCallback {
@@ -28,9 +29,9 @@
     }
 
     @Override
-    public void afterOperation(List<ILSMComponent> oldComponents, ILSMComponent newComponent)
+    public void afterOperation(LSMOperationType opType, List<ILSMComponent> oldComponents, ILSMComponent newComponent)
             throws HyracksDataException {
-        if (oldComponents != null && newComponent != null) {
+        if (newComponent != null) {
             LSMRTreeDiskComponent rtreeComponent = (LSMRTreeDiskComponent) newComponent;
             putLSNIntoMetadata(rtreeComponent.getRTree(), oldComponents);
             putLSNIntoMetadata(rtreeComponent.getBTree(), oldComponents);
@@ -41,7 +42,11 @@
     public long getComponentLSN(List<ILSMComponent> diskComponents) throws HyracksDataException {
         if (diskComponents == null) {
             // Implies a flush IO operation.
-            return lastLSN;
+            synchronized (this) {
+                long lsn = immutableLastLSNs[readIndex];
+                readIndex = (readIndex + 1) % immutableLastLSNs.length;
+                return lsn;
+            }
         }
         // Get max LSN from the diskComponents. Implies a merge IO operation or Recovery operation.
         long maxLSN = -1;
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/LogPage.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/LogPage.java
index 8921f35..a3f42a7 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/LogPage.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/LogPage.java
@@ -68,9 +68,8 @@
     @Override
     public void append(ILogRecord logRecord, long appendLSN) {
         logRecord.writeLogRecord(appendBuffer);
-        if (logRecord.getLogType() == LogType.UPDATE) {
-            logRecord.getTxnCtx().setLastLSN(logRecord.getResourceId(), appendLSN);
-        }
+        logRecord.getTxnCtx().setLastLSN(logRecord.getLogType() == LogType.UPDATE ? logRecord.getResourceId() : -1,
+                appendLSN);
         synchronized (this) {
             appendOffset += logRecord.getLogSize();
             if (IS_DEBUG_MODE) {
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/recovery/RecoveryManager.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/recovery/RecoveryManager.java
index fcb9aa1..95ee767 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/recovery/RecoveryManager.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/recovery/RecoveryManager.java
@@ -143,6 +143,7 @@
         int entityCommitLogCount = 0;
         int jobCommitLogCount = 0;
         int redoCount = 0;
+        int abortLogCount = 0;
         int jobId = -1;
 
         state = SystemState.RECOVERING;
@@ -210,7 +211,7 @@
                     entityCommitLogCount++;
                     break;
                 case LogType.ABORT:
-                    //ignore
+                    abortLogCount++;
                     break;
                 default:
                     throw new ACIDException("Unsupported LogType: " + logRecord.getLogType());
@@ -287,6 +288,7 @@
                              * log record.
                              *******************************************************************/
                             if (localResource == null) {
+                                logRecord = logReader.next();
                                 continue;
                             }
                             /*******************************************************************/
@@ -338,8 +340,8 @@
 
         if (LOGGER.isLoggable(Level.INFO)) {
             LOGGER.info("[RecoveryMgr] recovery is completed.");
-            LOGGER.info("[RecoveryMgr] Count: Update/EntityCommit/JobCommit/Redo = " + updateLogCount + "/"
-                    + entityCommitLogCount + "/" + jobCommitLogCount + "/" + redoCount);
+            LOGGER.info("[RecoveryMgr's recovery log count] update/entityCommit/jobCommit/abort/redo = " + updateLogCount + "/"
+                    + entityCommitLogCount + "/" + jobCommitLogCount + "/" + abortLogCount + "/" + redoCount);
         }
     }
 
@@ -664,7 +666,7 @@
         logReader.close();
         if (LOGGER.isLoggable(Level.INFO)) {
             LOGGER.info(" undone loser transaction's effect");
-            LOGGER.info("UpdateLogCount/CommitLogCount/UndoCount:" + updateLogCount + "/" + entityCommitLogCount + "/"
+            LOGGER.info("[RecoveryManager's rollback log count] update/entityCommit/undo:" + updateLogCount + "/" + entityCommitLogCount + "/"
                     + undoCount);
         }
     }
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionContext.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionContext.java
index 4468109..6fb91c8 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionContext.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionContext.java
@@ -128,9 +128,12 @@
         synchronized (indexMap) {
             firstLSN.compareAndSet(-1, LSN);
             lastLSN.set(Math.max(lastLSN.get(), LSN));
-            tempResourceIdForSetLSN.set(resourceId);
-            AbstractLSMIOOperationCallback ioOpCallback = indexMap.get(tempResourceIdForSetLSN);
-            ioOpCallback.updateLastLSN(LSN);
+            if (resourceId != -1) {
+                //Non-update log's resourceId is -1.
+                tempResourceIdForSetLSN.set(resourceId);
+                AbstractLSMIOOperationCallback ioOpCallback = indexMap.get(tempResourceIdForSetLSN);
+                ioOpCallback.updateLastLSN(LSN);
+            }
         }
     }