diff --git a/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/AsterixAppRuntimeContext.java b/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/AsterixAppRuntimeContext.java
index 52a67d3..d25f9cc 100644
--- a/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/AsterixAppRuntimeContext.java
+++ b/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/AsterixAppRuntimeContext.java
@@ -5,7 +5,7 @@
 
 import edu.uci.ics.asterix.common.config.GlobalConfig;
 import edu.uci.ics.asterix.transaction.management.exception.ACIDException;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 import edu.uci.ics.hyracks.api.application.INCApplicationContext;
 import edu.uci.ics.hyracks.api.io.IIOManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexLifecycleManager;
@@ -40,7 +40,7 @@
     private IIndexLifecycleManager indexLifecycleManager;
     private IFileMapManager fileMapManager;
     private IBufferCache bufferCache;
-    private TransactionProvider provider;
+    private TransactionSubsystem txnSubsystem;
 
     private ILSMFlushController flushController;
     private ILSMMergePolicy mergePolicy;
@@ -63,7 +63,7 @@
         IIOManager ioMgr = ncApplicationContext.getRootContext().getIOManager();
         bufferCache = new BufferCache(ioMgr, allocator, prs, fileMapManager, pageSize, numPages, Integer.MAX_VALUE);
         indexLifecycleManager = new IndexLifecycleManager(DEFAULT_LIFECYCLEMANAGER_MEMORY_BUDGET);
-        provider = new TransactionProvider(ncApplicationContext.getNodeId());
+        txnSubsystem = new TransactionSubsystem(ncApplicationContext.getNodeId());
 
         flushController = new FlushController();
         lsmIOScheduler = ImmediateScheduler.INSTANCE;
@@ -131,8 +131,8 @@
         return fileMapManager;
     }
 
-    public TransactionProvider getTransactionProvider() {
-        return provider;
+    public TransactionSubsystem getTransactionSubsystem() {
+        return txnSubsystem;
     }
 
     public IIndexLifecycleManager getIndexLifecycleManager() {
diff --git a/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/TransactionSubsystemProvider.java b/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/TransactionSubsystemProvider.java
new file mode 100644
index 0000000..85e5375
--- /dev/null
+++ b/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/TransactionSubsystemProvider.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.asterix.common.context;
+
+import edu.uci.ics.asterix.transaction.management.service.transaction.ITransactionSubsystemProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+
+/**
+ * The purpose of this provider is to work around a cyclic dependency between asterix-common and asterix-transactions.
+ * The operation callbacks would depend on the AsterixAppRuntimeContext to get the transaction subsystem,
+ * while at the same time the AsterixAppRuntimeContext depends on asterix-transactions for the TransactionSubsystem.
+ */
+public class TransactionSubsystemProvider implements ITransactionSubsystemProvider {
+    @Override
+    public TransactionSubsystem getTransactionSubsystem(IHyracksTaskContext ctx) {
+        AsterixAppRuntimeContext runtimeCtx = (AsterixAppRuntimeContext) ctx.getJobletContext().getApplicationContext()
+                .getApplicationObject();
+        return runtimeCtx.getTransactionSubsystem();
+    }
+}
diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/MetadataNode.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/MetadataNode.java
index ba84f16..301c335 100644
--- a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/MetadataNode.java
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/MetadataNode.java
@@ -58,7 +58,7 @@
 import edu.uci.ics.asterix.transaction.management.service.transaction.JobId;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionContext;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionManagementConstants.LockManagerConstants.LockMode;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparator;
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
@@ -88,7 +88,7 @@
     private static final DatasetId METADATA_DATASET_ID = new DatasetId(MetadataPrimaryIndexes.METADATA_DATASET_ID);
 
     private IIndexLifecycleManager indexLifecycleManager;
-    private TransactionProvider transactionProvider;
+    private TransactionSubsystem transactionProvider;
 
     public static final MetadataNode INSTANCE = new MetadataNode();
 
@@ -97,7 +97,7 @@
     }
 
     public void initialize(AsterixAppRuntimeContext runtimeContext) {
-        this.transactionProvider = runtimeContext.getTransactionProvider();
+        this.transactionProvider = runtimeContext.getTransactionSubsystem();
         this.indexLifecycleManager = runtimeContext.getIndexLifecycleManager();
     }
 
diff --git a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/bootstrap/MetadataBootstrap.java b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/bootstrap/MetadataBootstrap.java
index a1a510c..91e734d 100644
--- a/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/bootstrap/MetadataBootstrap.java
+++ b/asterix-metadata/src/main/java/edu/uci/ics/asterix/metadata/bootstrap/MetadataBootstrap.java
@@ -126,10 +126,10 @@
         initLocalIndexArrays();
 
         boolean isNewUniverse = true;
-        TransactionalResourceRepository resourceRepository = runtimeContext.getTransactionProvider()
+        TransactionalResourceRepository resourceRepository = runtimeContext.getTransactionSubsystem()
                 .getTransactionalResourceRepository();
         resourceRepository.registerTransactionalResourceManager(ResourceType.LSM_BTREE, new IndexResourceManager(
-                ResourceType.LSM_BTREE, runtimeContext.getTransactionProvider()));
+                ResourceType.LSM_BTREE, runtimeContext.getTransactionSubsystem()));
 
         metadataNodeName = asterixProperties.getMetadataNodeName();
         isNewUniverse = asterixProperties.isNewUniverse();
diff --git a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/job/listener/JobEventListenerFactory.java b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/job/listener/JobEventListenerFactory.java
index 8f2b892..471a0b8 100644
--- a/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/job/listener/JobEventListenerFactory.java
+++ b/asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/job/listener/JobEventListenerFactory.java
@@ -31,7 +31,7 @@
             public void jobletFinish(JobStatus jobStatus) {
                 try {
                     ITransactionManager txnManager = ((AsterixAppRuntimeContext) jobletContext.getApplicationContext()
-                            .getApplicationObject()).getTransactionProvider().getTransactionManager();
+                            .getApplicationObject()).getTransactionSubsystem().getTransactionManager();
                     TransactionContext txnContext = txnManager.getTransactionContext(jobId);
                     txnContext.setTransactionType(transactionalWrite ? TransactionType.READ_WRITE
                             : TransactionType.READ);
@@ -45,7 +45,7 @@
             public void jobletStart() {
                 try {
                     ((AsterixAppRuntimeContext) jobletContext.getApplicationContext().getApplicationObject())
-                            .getTransactionProvider().getTransactionManager().getTransactionContext(jobId);
+                            .getTransactionSubsystem().getTransactionManager().getTransactionContext(jobId);
                 } catch (ACIDException e) {
                     throw new Error(e);
                 }
diff --git a/asterix-transactions/pom.xml b/asterix-transactions/pom.xml
index cb7d4e2..203c520 100644
--- a/asterix-transactions/pom.xml
+++ b/asterix-transactions/pom.xml
@@ -34,7 +34,7 @@
   	</dependency>
 	    <dependency>
 	    	<groupId>edu.uci.ics.hyracks</groupId>
-	    	<artifactId>hyracks-storage-am-lsm-common</artifactId>
+	    	<artifactId>hyracks-storage-am-lsm-btree</artifactId>
 	    	<version>0.2.2-SNAPSHOT</version>
 	    </dependency>
 	</dependencies>
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/opcallbacks/AbstractOperationCallback.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/opcallbacks/AbstractOperationCallback.java
new file mode 100644
index 0000000..58dd2d0
--- /dev/null
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/opcallbacks/AbstractOperationCallback.java
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.asterix.transaction.management.opcallbacks;
+
+import edu.uci.ics.asterix.transaction.management.service.locking.ILockManager;
+import edu.uci.ics.asterix.transaction.management.service.transaction.DatasetId;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionContext;
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryHashFunction;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+
+public abstract class AbstractOperationCallback {
+    protected final DatasetId datasetId;
+    protected final int[] primaryKeyFields;
+    protected final IBinaryHashFunction[] primaryKeyHashFunctions;
+    protected final ILockManager lockManager;
+    protected final TransactionContext txnCtx;
+
+    public AbstractOperationCallback(DatasetId datasetId, int[] primaryKeyFields,
+            IBinaryHashFunction[] primaryKeyHashFunctions, TransactionContext txnCtx, ILockManager lockManager) {
+        this.datasetId = datasetId;
+        this.primaryKeyFields = primaryKeyFields;
+        this.primaryKeyHashFunctions = primaryKeyHashFunctions;
+        this.txnCtx = txnCtx;
+        this.lockManager = lockManager;
+    }
+
+    public int computePrimaryKeyHashValue(ITupleReference tuple, int[] primaryKeyFields,
+            IBinaryHashFunction[] primaryKeyHashFunctions) {
+        int h = 0;
+        for (int i = 0; i < primaryKeyFields.length; i++) {
+            int entityFieldIdx = primaryKeyFields[i];
+            int fh = primaryKeyHashFunctions[i].hash(tuple.getFieldData(entityFieldIdx),
+                    tuple.getFieldStart(entityFieldIdx), tuple.getFieldLength(entityFieldIdx));
+            h = h * 31 + fh;
+        }
+        return h;
+    }
+}
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/opcallbacks/LSMBTreeModificationOperationCallback.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/opcallbacks/LSMBTreeModificationOperationCallback.java
new file mode 100644
index 0000000..6e17f3f
--- /dev/null
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/opcallbacks/LSMBTreeModificationOperationCallback.java
@@ -0,0 +1,74 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.asterix.transaction.management.opcallbacks;
+
+import edu.uci.ics.asterix.transaction.management.exception.ACIDException;
+import edu.uci.ics.asterix.transaction.management.service.locking.ILockManager;
+import edu.uci.ics.asterix.transaction.management.service.logging.IndexLogger;
+import edu.uci.ics.asterix.transaction.management.service.transaction.DatasetId;
+import edu.uci.ics.asterix.transaction.management.service.transaction.IResourceManager.ResourceType;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionContext;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionManagementConstants.LockManagerConstants.LockMode;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryHashFunction;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
+import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
+import edu.uci.ics.hyracks.storage.am.lsm.btree.tuples.LSMBTreeTupleReference;
+
+public class LSMBTreeModificationOperationCallback extends AbstractOperationCallback implements
+        IModificationOperationCallback {
+
+    protected final long resourceId;
+    protected final IndexOperation indexOp;
+    protected final TransactionSubsystem txnSubsystem;
+    
+    public LSMBTreeModificationOperationCallback(DatasetId datasetId, int[] primaryKeyFields,
+            IBinaryHashFunction[] primaryKeyHashFunctions, TransactionContext txnCtx, ILockManager lockManager,
+            TransactionSubsystem txnSubsystem, long resourceId, IndexOperation indexOp) {
+        super(datasetId, primaryKeyFields, primaryKeyHashFunctions, txnCtx, lockManager);
+        this.resourceId = resourceId;
+        this.indexOp = indexOp;
+        this.txnSubsystem = txnSubsystem;
+    }
+
+    @Override
+    public void before(ITupleReference tuple) throws HyracksDataException {
+        int pkHash = computePrimaryKeyHashValue(tuple, primaryKeyFields, primaryKeyHashFunctions);
+        try {
+            lockManager.lock(datasetId, pkHash, LockMode.X, txnCtx);
+        } catch (ACIDException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+
+    @Override
+    public void found(ITupleReference before, ITupleReference after) throws HyracksDataException {
+        IndexLogger logger = txnSubsystem.getTreeLoggerRepository().getIndexLogger(resourceId, ResourceType.LSM_BTREE);
+        int pkHash = computePrimaryKeyHashValue(after, primaryKeyFields, primaryKeyHashFunctions);
+        LSMBTreeTupleReference lsmBTreeTuple = (LSMBTreeTupleReference) before;
+        IndexOperation oldOp = IndexOperation.INSERT;
+        if (lsmBTreeTuple.isAntimatter()) {
+            oldOp = IndexOperation.DELETE;
+        }
+        try {
+            logger.generateLogRecord(txnSubsystem, txnCtx, datasetId.getId(), pkHash, resourceId, indexOp, after, oldOp, before);
+        } catch (ACIDException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+}
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/opcallbacks/OperationCallbackFactory.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/opcallbacks/OperationCallbackFactory.java
new file mode 100644
index 0000000..47e37b8
--- /dev/null
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/opcallbacks/OperationCallbackFactory.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.asterix.transaction.management.opcallbacks;
+
+import edu.uci.ics.asterix.transaction.management.exception.ACIDException;
+import edu.uci.ics.asterix.transaction.management.service.transaction.DatasetId;
+import edu.uci.ics.asterix.transaction.management.service.transaction.ITransactionSubsystemProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.JobId;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionContext;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryHashFunction;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
+import edu.uci.ics.hyracks.storage.am.common.api.IOperationCallbackFactory;
+import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
+
+public class OperationCallbackFactory implements IOperationCallbackFactory {
+
+    private static final long serialVersionUID = 1L;
+    
+    private final JobId jobId;
+    private final DatasetId datasetId;
+    private final int[] entityIdFields;
+    private final IBinaryHashFunction[] entityIdFieldHashFunctions;
+    private final ITransactionSubsystemProvider txnSubsystemProvider;
+    
+    public OperationCallbackFactory(JobId jobId, DatasetId datasetId, int[] entityIdFields,
+            IBinaryHashFunction[] entityIdFieldHashFunctions, ITransactionSubsystemProvider txnSubsystemProvider) {
+        this.jobId = jobId;
+        this.datasetId = datasetId;
+        this.entityIdFields = entityIdFields;
+        this.entityIdFieldHashFunctions = entityIdFieldHashFunctions;
+        this.txnSubsystemProvider = txnSubsystemProvider;
+    }
+    
+    @Override
+    public IModificationOperationCallback createModificationOperationCallback(long resourceId, IHyracksTaskContext ctx) throws HyracksDataException {
+        // TODO: Implement this one.
+        TransactionSubsystem txnSubsystem = txnSubsystemProvider.getTransactionSubsystem(ctx);
+        return null;
+    }
+
+    @Override
+    public ISearchOperationCallback createSearchOperationCallback(long resourceId, IHyracksTaskContext ctx)
+            throws HyracksDataException {
+        TransactionSubsystem txnSubsystem = txnSubsystemProvider.getTransactionSubsystem(ctx);
+        try {
+            TransactionContext txnCtx = txnSubsystem.getTransactionManager().getTransactionContext(jobId);
+            return new SearchOperationCallback(datasetId, entityIdFields, entityIdFieldHashFunctions,
+                    txnSubsystem.getLockManager(), txnCtx);
+        } catch (ACIDException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+
+}
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/opcallbacks/SearchOperationCallback.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/opcallbacks/SearchOperationCallback.java
new file mode 100644
index 0000000..bebe823
--- /dev/null
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/opcallbacks/SearchOperationCallback.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.asterix.transaction.management.opcallbacks;
+
+import edu.uci.ics.asterix.transaction.management.exception.ACIDException;
+import edu.uci.ics.asterix.transaction.management.service.locking.ILockManager;
+import edu.uci.ics.asterix.transaction.management.service.transaction.DatasetId;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionContext;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionManagementConstants.LockManagerConstants.LockMode;
+import edu.uci.ics.hyracks.api.dataflow.value.IBinaryHashFunction;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
+
+public class SearchOperationCallback extends AbstractOperationCallback implements ISearchOperationCallback {
+
+    public SearchOperationCallback(DatasetId datasetId, int[] entityIdFields,
+            IBinaryHashFunction[] entityIdFieldHashFunctions, ILockManager lockManager, TransactionContext txnCtx) {
+        super(datasetId, entityIdFields, entityIdFieldHashFunctions, txnCtx, lockManager);
+    }
+
+    @Override
+    public boolean proceed(ITupleReference tuple) throws HyracksDataException {
+        int pkHash = computePrimaryKeyHashValue(tuple, primaryKeyFields, primaryKeyHashFunctions);
+        try {
+            return lockManager.tryLock(datasetId, pkHash, LockMode.S, txnCtx);
+        } catch (ACIDException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+
+    @Override
+    public void reconcile(ITupleReference tuple) throws HyracksDataException {
+        int pkHash = computePrimaryKeyHashValue(tuple, primaryKeyFields, primaryKeyHashFunctions);
+        try {
+            lockManager.lock(datasetId, pkHash, LockMode.S, txnCtx);
+        } catch (ACIDException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+
+    @Override
+    public void cancel(ITupleReference tuple) throws HyracksDataException {
+        int pkHash = computePrimaryKeyHashValue(tuple, primaryKeyFields, primaryKeyHashFunctions);
+        try {
+            lockManager.unlock(datasetId, pkHash, txnCtx);
+        } catch (ACIDException e) {
+            throw new HyracksDataException(e);
+        }
+    }
+}
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManager.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManager.java
index 43c4975..0691504 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManager.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManager.java
@@ -15,25 +15,21 @@
 
 package edu.uci.ics.asterix.transaction.management.service.locking;
 
-import java.io.Serializable;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
-import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import edu.uci.ics.asterix.transaction.management.exception.ACIDException;
-import edu.uci.ics.asterix.transaction.management.service.logging.LogType;
 import edu.uci.ics.asterix.transaction.management.service.transaction.DatasetId;
-import edu.uci.ics.asterix.transaction.management.service.transaction.ITransactionManager;
 import edu.uci.ics.asterix.transaction.management.service.transaction.ITransactionManager.TransactionState;
 import edu.uci.ics.asterix.transaction.management.service.transaction.JobId;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionContext;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionManagementConstants.LockManagerConstants.LockMode;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 
 /**
  * An implementation of the ILockManager interface for the
@@ -49,7 +45,7 @@
     private static final int LOCK_MANAGER_INITIAL_HASH_TABLE_SIZE = 50;// do we need this?
     public static final boolean IS_DEBUG_MODE = false;//true
 
-    private TransactionProvider transactionProvider;
+    private TransactionSubsystem txnSubsystem;
 
     //all threads accessing to LockManager's tables such as jobHT and datasetResourceHT
     //are serialized through LockTableLatch. All threads waiting the latch will be fairly served
@@ -77,8 +73,8 @@
     //----------------------------------------------------------    
     private Map<JobId, TransactionContext> transactionContextRepository = new HashMap<JobId, TransactionContext>();
 
-    public LockManager(TransactionProvider txnProvider) throws ACIDException {
-        this.transactionProvider = txnProvider;
+    public LockManager(TransactionSubsystem txnSubsystem) throws ACIDException {
+        this.txnSubsystem = txnSubsystem;
         this.lockTableLatch = new ReentrantReadWriteLock(true);
         this.waiterLatch = new ReentrantReadWriteLock(true);
         this.jobHT = new HashMap<JobId, JobInfo>();
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManagerDeterministicUnitTest.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManagerDeterministicUnitTest.java
index 063194b..a6ed47c 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManagerDeterministicUnitTest.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManagerDeterministicUnitTest.java
@@ -13,7 +13,7 @@
 import edu.uci.ics.asterix.transaction.management.service.transaction.JobId;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionContext;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionManagementConstants.LockManagerConstants.LockMode;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 
 public class LockManagerDeterministicUnitTest {
 
@@ -29,7 +29,7 @@
 class LockRequestController implements Runnable {
 
     public static final boolean IS_DEBUG_MODE = false;
-    TransactionProvider txnProvider;
+    TransactionSubsystem txnProvider;
     WorkerReadyQueue workerReadyQueue;
     ArrayList<LockRequest> requestList;
     ArrayList<ArrayList<Integer>> expectedResultList;
@@ -39,7 +39,7 @@
     long defaultWaitTime;
 
     public LockRequestController(String requestFileName) throws ACIDException {
-        this.txnProvider = new TransactionProvider("LockManagerPredefinedUnitTest");;
+        this.txnProvider = new TransactionSubsystem("LockManagerPredefinedUnitTest");;
         this.workerReadyQueue = new WorkerReadyQueue();
         this.requestList = new ArrayList<LockRequest>();
         this.expectedResultList = new ArrayList<ArrayList<Integer>>();
@@ -354,7 +354,7 @@
 class LockRequestWorker implements Runnable {
 
     String threadName;
-    TransactionProvider txnProvider;
+    TransactionSubsystem txnProvider;
     ILockManager lockMgr;
     WorkerReadyQueue workerReadyQueue;
     LockRequest lockRequest;
@@ -362,7 +362,7 @@
     boolean isAwaken;
     boolean isDone;
 
-    public LockRequestWorker(TransactionProvider txnProvider, WorkerReadyQueue workerReadyQueue, String threadName) {
+    public LockRequestWorker(TransactionSubsystem txnProvider, WorkerReadyQueue workerReadyQueue, String threadName) {
         this.txnProvider = txnProvider;
         this.lockMgr = txnProvider.getLockManager();
         this.workerReadyQueue = workerReadyQueue;
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManagerRandomUnitTest.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManagerRandomUnitTest.java
index 7add782..a8860bd 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManagerRandomUnitTest.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManagerRandomUnitTest.java
@@ -9,7 +9,7 @@
 import edu.uci.ics.asterix.transaction.management.service.transaction.JobId;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionContext;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionManagementConstants.LockManagerConstants.LockMode;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 
 /**
  * LockManagerUnitTest: unit test of LockManager
@@ -28,7 +28,7 @@
 
     public static void main(String args[]) throws ACIDException {
         int i;
-        TransactionProvider txnProvider = new TransactionProvider("LockManagerRandomUnitTest");
+        TransactionSubsystem txnProvider = new TransactionSubsystem("LockManagerRandomUnitTest");
         rand = new Random(System.currentTimeMillis());
         for (i = 0; i < MAX_NUM_OF_ENTITY_LOCK_JOB; i++) {
             System.out.println("Creating " + i + "th EntityLockJob..");
@@ -46,7 +46,7 @@
         }
     }
 
-    private static void generateEntityLockThread(TransactionProvider txnProvider) {
+    private static void generateEntityLockThread(TransactionSubsystem txnProvider) {
         Thread t;
         int childCount = rand.nextInt(MAX_NUM_OF_THREAD_IN_A_JOB);
         if (MAX_NUM_OF_THREAD_IN_A_JOB != 0 && childCount == 0) {
@@ -61,7 +61,7 @@
         }
     }
 
-    private static void generateDatasetLockThread(TransactionProvider txnProvider) {
+    private static void generateDatasetLockThread(TransactionSubsystem txnProvider) {
         Thread t;
 //        int childCount = rand.nextInt(MAX_NUM_OF_THREAD_IN_A_JOB);
 //        if (MAX_NUM_OF_THREAD_IN_A_JOB != 0 && childCount == 0) {
@@ -78,7 +78,7 @@
         }
     }
 
-    private static void generateEntityLockUpgradeThread(TransactionProvider txnProvider) {
+    private static void generateEntityLockUpgradeThread(TransactionSubsystem txnProvider) {
         int i;
         Thread t;
         int childCount = MAX_NUM_OF_THREAD_IN_A_JOB;
@@ -97,7 +97,7 @@
         t.start();
     }
 
-    private static TransactionContext generateTxnContext(TransactionProvider txnProvider) {
+    private static TransactionContext generateTxnContext(TransactionSubsystem txnProvider) {
         try {
             return new TransactionContext(new JobId(jobId++), txnProvider);
         } catch (ACIDException e) {
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/ILogManager.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/ILogManager.java
index 40f716c..6ff5fd3 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/ILogManager.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/ILogManager.java
@@ -19,7 +19,7 @@
 import edu.uci.ics.asterix.transaction.management.exception.ACIDException;
 import edu.uci.ics.asterix.transaction.management.service.logging.IndexLogger.ReusableLogContentObject;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionContext;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 
 public interface ILogManager {
 
@@ -102,8 +102,8 @@
      * Returns the Transaction Provider associated with this ILogManager
      * instance
      * 
-     * @return TransactionProvider
+     * @return TransactionSubsystem
      */
-    public TransactionProvider getTransactionProvider();
+    public TransactionSubsystem getTransactionSubsystem();
 
 }
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/IndexLogger.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/IndexLogger.java
index 48a9dbf..85d349b 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/IndexLogger.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/IndexLogger.java
@@ -22,7 +22,7 @@
 import edu.uci.ics.asterix.transaction.management.resource.ICloseable;
 import edu.uci.ics.asterix.transaction.management.service.transaction.IResourceManager.ResourceType;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionContext;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndex;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
@@ -62,7 +62,7 @@
         jobId2ReusableLogContentObjectRepositoryMap.remove(context.getJobId());
     }
 
-    public void generateLogRecord(TransactionProvider provider, TransactionContext context, int datasetId,
+    public void generateLogRecord(TransactionSubsystem txnSubsystem, TransactionContext context, int datasetId,
             int PKHashValue, long resourceId, IndexOperation newOperation, ITupleReference newValue,
             IndexOperation oldOperation, ITupleReference oldValue) throws ACIDException {
 
@@ -96,7 +96,7 @@
 
         reusableLogContentObject = reusableLogContentObjectRepository.getObject(Thread.currentThread().getId());
         if (reusableLogContentObject == null) {
-            LogicalLogLocator logicalLogLocator = LogUtil.getDummyLogicalLogLocator(provider.getLogManager());
+            LogicalLogLocator logicalLogLocator = LogUtil.getDummyLogicalLogLocator(txnSubsystem.getLogManager());
             reusableLogContentObject = new ReusableLogContentObject(logicalLogLocator, newOperation, newValue,
                     oldOperation, oldValue);
             reusableLogContentObjectRepository.putObject(Thread.currentThread().getId(), reusableLogContentObject);
@@ -111,7 +111,7 @@
                 .bytesRequired(newValue);
         logContentSize += 1/*OldOperation*/+ 4/*oldValueLength*/+ tupleWriter.bytesRequired(oldValue);
 
-        provider.getLogManager().log(LogType.UPDATE, context, datasetId, PKHashValue, resourceId, resourceType,
+        txnSubsystem.getLogManager().log(LogType.UPDATE, context, datasetId, PKHashValue, resourceId, resourceType,
                 logContentSize, reusableLogContentObject, this, reusableLogContentObject.getLogicalLogLocator());
     }
 
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/IndexLoggerRepository.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/IndexLoggerRepository.java
index 54790b3..7eefe37 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/IndexLoggerRepository.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/IndexLoggerRepository.java
@@ -18,16 +18,16 @@
 import java.util.Map;
 
 import edu.uci.ics.asterix.transaction.management.service.transaction.MutableResourceId;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndex;
 
 public class IndexLoggerRepository {
 
     private final Map<MutableResourceId, IndexLogger> loggers = new HashMap<MutableResourceId, IndexLogger>();
-    private final TransactionProvider provider;
+    private final TransactionSubsystem provider;
     private MutableResourceId mutableResourceId;
 
-    public IndexLoggerRepository(TransactionProvider provider) {
+    public IndexLoggerRepository(TransactionSubsystem provider) {
         this.provider = provider;
         mutableResourceId = new MutableResourceId(0);
     }
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/IndexResourceManager.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/IndexResourceManager.java
index 19f055c..5e6ef34 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/IndexResourceManager.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/IndexResourceManager.java
@@ -16,7 +16,7 @@
 
 import edu.uci.ics.asterix.transaction.management.exception.ACIDException;
 import edu.uci.ics.asterix.transaction.management.service.transaction.IResourceManager;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndex;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
@@ -28,9 +28,9 @@
 
     public final byte resourceType;
 
-    private final TransactionProvider provider;
+    private final TransactionSubsystem provider;
 
-    public IndexResourceManager(byte resourceType, TransactionProvider provider) {
+    public IndexResourceManager(byte resourceType, TransactionSubsystem provider) {
         this.resourceType = resourceType;
         this.provider = provider;
     }
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/LogManager.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/LogManager.java
index 5736105..f295347 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/LogManager.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/LogManager.java
@@ -32,7 +32,7 @@
 import edu.uci.ics.asterix.transaction.management.service.logging.IndexLogger.ReusableLogContentObject;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionContext;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionManagementConstants;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 
 public class LogManager implements ILogManager {
 
@@ -45,7 +45,7 @@
      */
 
     private static final Logger LOGGER = Logger.getLogger(LogManager.class.getName());
-    private TransactionProvider provider;
+    private TransactionSubsystem provider;
     private LogManagerProperties logManagerProperties;
 
     /*
@@ -181,13 +181,13 @@
         return lastFlushedLsn.addAndGet(delta);
     }
 
-    public LogManager(TransactionProvider provider) throws ACIDException {
+    public LogManager(TransactionSubsystem provider) throws ACIDException {
         this.provider = provider;
         initLogManagerProperties(null);
         initLogManager();
     }
 
-    public LogManager(TransactionProvider provider, LogManagerProperties logConfiguration) throws ACIDException {
+    public LogManager(TransactionSubsystem provider, LogManagerProperties logConfiguration) throws ACIDException {
         this.provider = provider;
         initLogManagerProperties(logConfiguration);
         initLogManager();
@@ -864,7 +864,7 @@
     }
 
     @Override
-    public TransactionProvider getTransactionProvider() {
+    public TransactionSubsystem getTransactionSubsystem() {
         return provider;
     }
 }
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 c810170..77a7b1b 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
@@ -43,7 +43,7 @@
 import edu.uci.ics.asterix.transaction.management.service.transaction.IResourceManager;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionContext;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionManagementConstants;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 
 /**
  * This is the Recovery Manager and is responsible for rolling back a
@@ -54,7 +54,7 @@
 public class RecoveryManager implements IRecoveryManager {
 
     private static final Logger LOGGER = Logger.getLogger(RecoveryManager.class.getName());
-    private TransactionProvider transactionProvider;
+    private TransactionSubsystem transactionProvider;
 
     /**
      * A file at a known location that contains the LSN of the last log record
@@ -65,7 +65,7 @@
     private Map<Long, TransactionTableEntry> transactionTable;
     private Map<Long, List<PhysicalLogLocator>> dirtyPagesTable;
 
-    public RecoveryManager(TransactionProvider TransactionProvider) throws ACIDException {
+    public RecoveryManager(TransactionSubsystem TransactionProvider) throws ACIDException {
         this.transactionProvider = TransactionProvider;
         try {
             FileUtil.createFileIfNotExists(checkpoint_record_file);
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/ITransactionManager.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/ITransactionManager.java
index efe69a5..3f55ac9 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/ITransactionManager.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/ITransactionManager.java
@@ -106,9 +106,9 @@
      * transaction eco-system consists of a Log Manager, a Recovery Manager, a
      * Transaction Manager and a Lock Manager.
      * 
-     * @see TransactionProvider
+     * @see TransactionSubsystem
      * @return TransactionProvider
      */
-    public TransactionProvider getTransactionProvider();
+    public TransactionSubsystem getTransactionProvider();
 
 }
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/ITransactionSubsystemProvider.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/ITransactionSubsystemProvider.java
new file mode 100644
index 0000000..b5eb7f8
--- /dev/null
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/ITransactionSubsystemProvider.java
@@ -0,0 +1,22 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.asterix.transaction.management.service.transaction;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+
+public interface ITransactionSubsystemProvider {
+    public TransactionSubsystem getTransactionSubsystem(IHyracksTaskContext ctx);
+}
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 587f358..8c93477 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
@@ -44,7 +44,7 @@
     }
 
     private static final long serialVersionUID = -6105616785783310111L;
-    private TransactionProvider transactionProvider;
+    private TransactionSubsystem transactionProvider;
     private LogicalLogLocator lastLogLocator;
     private TransactionState txnState;
     private long startWaitTime;
@@ -65,7 +65,7 @@
         resources.add(resource);
     }
 
-    public TransactionContext(JobId jobId, TransactionProvider transactionProvider) throws ACIDException {
+    public TransactionContext(JobId jobId, TransactionSubsystem transactionProvider) throws ACIDException {
         this.jobId = jobId;
         this.transactionProvider = transactionProvider;
         init();
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionManager.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionManager.java
index 9f99c96..0af6303 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionManager.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionManager.java
@@ -28,10 +28,10 @@
  */
 public class TransactionManager implements ITransactionManager {
     private static final Logger LOGGER = Logger.getLogger(TransactionManager.class.getName());
-    private final TransactionProvider transactionProvider;
+    private final TransactionSubsystem transactionProvider;
     private Map<JobId, TransactionContext> transactionContextRepository = new HashMap<JobId, TransactionContext>();
 
-    public TransactionManager(TransactionProvider provider) {
+    public TransactionManager(TransactionSubsystem provider) {
         this.transactionProvider = provider;
     }
 
@@ -117,7 +117,7 @@
     }
 
     @Override
-    public TransactionProvider getTransactionProvider() {
+    public TransactionSubsystem getTransactionProvider() {
         return transactionProvider;
     }
 }
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionProvider.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionSubsystem.java
similarity index 96%
rename from asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionProvider.java
rename to asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionSubsystem.java
index 84414b5..88082b0 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionProvider.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionSubsystem.java
@@ -28,7 +28,7 @@
  * Provider for all the sub-systems (transaction/lock/log/recovery) managers.
  * Users of transaction sub-systems must obtain them from the provider.
  */
-public class TransactionProvider {
+public class TransactionSubsystem {
     private final String id;
     private final ILogManager logManager;
     private final ILockManager lockManager;
@@ -37,7 +37,7 @@
     private final TransactionalResourceRepository resourceRepository;
     private final IndexLoggerRepository loggerRepository;
 
-    public TransactionProvider(String id) throws ACIDException {
+    public TransactionSubsystem(String id) throws ACIDException {
         this.id = id;
         this.transactionManager = new TransactionManager(this);
         this.logManager = new LogManager(this);
diff --git a/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/logging/test/RecoverySimulator.java b/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/logging/test/RecoverySimulator.java
index 3a288a2..c086954 100644
--- a/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/logging/test/RecoverySimulator.java
+++ b/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/logging/test/RecoverySimulator.java
@@ -18,7 +18,7 @@
 
 import edu.uci.ics.asterix.transaction.management.exception.ACIDException;
 import edu.uci.ics.asterix.transaction.management.service.recovery.IRecoveryManager;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 
 public class RecoverySimulator {
 
@@ -31,7 +31,7 @@
     public static void main(String args[]) throws IOException, ACIDException {
         String id = "nc1";
         try {
-            TransactionProvider factory = new TransactionProvider(id);
+            TransactionSubsystem factory = new TransactionSubsystem(id);
             IRecoveryManager recoveryManager = factory.getRecoveryManager();
             recoveryManager.startRecovery(true);
         } catch (ACIDException acide) {
diff --git a/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/logging/test/TransactionWorkloadSimulator.java b/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/logging/test/TransactionWorkloadSimulator.java
index 9edadd9..5d68911 100644
--- a/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/logging/test/TransactionWorkloadSimulator.java
+++ b/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/logging/test/TransactionWorkloadSimulator.java
@@ -32,13 +32,13 @@
 import edu.uci.ics.asterix.transaction.management.service.transaction.IResourceManager.ResourceType;
 import edu.uci.ics.asterix.transaction.management.service.transaction.JobIdFactory;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionContext;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 
 public class TransactionWorkloadSimulator {
 
     public static ILogManager logManager;
     public static ILockManager lockManager;
-    TransactionProvider provider;
+    TransactionSubsystem provider;
 
     public static WorkloadProperties workload;
     Transaction[] transactions;
@@ -49,7 +49,7 @@
     }
 
     public void beginWorkload() throws ACIDException {
-        provider = new TransactionProvider("nc1");
+        provider = new TransactionSubsystem("nc1");
         logManager = provider.getLogManager();
         lockManager = provider.getLockManager();
         provider.getTransactionalResourceRepository().registerTransactionalResourceManager(DummyResourceMgr.id,
@@ -98,7 +98,7 @@
 class SingleTransactionContextFactory {
     private static TransactionContext context;
 
-    public static TransactionContext getContext(TransactionProvider provider) throws ACIDException {
+    public static TransactionContext getContext(TransactionSubsystem provider) throws ACIDException {
         if (context == null) {
             context = new TransactionContext(JobIdFactory.generateJobId(), provider);
         }
@@ -108,7 +108,7 @@
 
 class MultipleTransactionContextFactory {
 
-    public static TransactionContext getContext(TransactionProvider provider) throws ACIDException {
+    public static TransactionContext getContext(TransactionSubsystem provider) throws ACIDException {
         return new TransactionContext(JobIdFactory.generateJobId(), provider);
     }
 }
@@ -125,11 +125,11 @@
     //private byte[] resourceID = new byte[1];
     private int resourceID;
     private int myLogCount = 0;
-    private TransactionProvider transactionProvider;
+    private TransactionSubsystem transactionProvider;
     private ILogManager logManager;
     private DatasetId tempDatasetId = new DatasetId(-1);
 
-    public Transaction(TransactionProvider provider, String name, boolean singleTransaction) throws ACIDException {
+    public Transaction(TransactionSubsystem provider, String name, boolean singleTransaction) throws ACIDException {
         this.name = name;
         this.transactionProvider = provider;
         if (singleTransaction) {
diff --git a/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/test/LogRecordReader.java b/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/test/LogRecordReader.java
index 899dbde..d97a286 100644
--- a/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/test/LogRecordReader.java
+++ b/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/test/LogRecordReader.java
@@ -28,13 +28,13 @@
 import edu.uci.ics.asterix.transaction.management.service.logging.LogUtil;
 import edu.uci.ics.asterix.transaction.management.service.logging.LogicalLogLocator;
 import edu.uci.ics.asterix.transaction.management.service.logging.PhysicalLogLocator;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 
 public class LogRecordReader {
 
     ILogManager logManager;
 
-    public LogRecordReader(TransactionProvider factory) throws ACIDException {
+    public LogRecordReader(TransactionSubsystem factory) throws ACIDException {
         logManager = factory.getLogManager();
     }
 
diff --git a/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/test/TransactionSimulator.java b/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/test/TransactionSimulator.java
index cff5ed0..98585b5 100644
--- a/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/test/TransactionSimulator.java
+++ b/asterix-transactions/src/test/java/edu/uci/ics/asterix/transaction/management/test/TransactionSimulator.java
@@ -34,7 +34,7 @@
 import edu.uci.ics.asterix.transaction.management.service.transaction.JobId;
 import edu.uci.ics.asterix.transaction.management.service.transaction.JobIdFactory;
 import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionContext;
-import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionProvider;
+import edu.uci.ics.asterix.transaction.management.service.transaction.TransactionSubsystem;
 
 public class TransactionSimulator {
 
@@ -46,11 +46,11 @@
     private ILogger logger;
     private IResource resource;
     private LogicalLogLocator memLSN;
-    private TransactionProvider transactionProvider;
+    private TransactionSubsystem transactionProvider;
 
     public TransactionSimulator(IResource resource, IResourceManager resourceMgr) throws ACIDException {
         String id = "nc1";
-        transactionProvider = new TransactionProvider(id);
+        transactionProvider = new TransactionSubsystem(id);
         transactionManager = transactionProvider.getTransactionManager();
         logManager = transactionProvider.getLogManager();
         lockManager = transactionProvider.getLockManager();