Use YangInstanceIdentifier.EMPTY
[controller.git] / opendaylight / md-sal / sal-distributed-datastore / src / test / java / org / opendaylight / controller / cluster / datastore / TransactionProxyTest.java
index 8278d3cffceaa6b82357c08c4ab62e33ff53fafe..7d23c0affc6063b2c72ca4cdea839baca0460fc8 100644 (file)
@@ -1,59 +1,79 @@
+/*
+ * Copyright (c) 2014, 2015 Cisco Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+
 package org.opendaylight.controller.cluster.datastore;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
 import static org.mockito.Matchers.any;
 import static org.mockito.Matchers.anyString;
 import static org.mockito.Matchers.eq;
 import static org.mockito.Matchers.isA;
 import static org.mockito.Mockito.doReturn;
-import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
-import static org.opendaylight.controller.cluster.datastore.TransactionProxy.TransactionType.READ_ONLY;
-import static org.opendaylight.controller.cluster.datastore.TransactionProxy.TransactionType.READ_WRITE;
-import static org.opendaylight.controller.cluster.datastore.TransactionProxy.TransactionType.WRITE_ONLY;
+import static org.opendaylight.controller.cluster.datastore.TransactionType.READ_ONLY;
+import static org.opendaylight.controller.cluster.datastore.TransactionType.READ_WRITE;
+import static org.opendaylight.controller.cluster.datastore.TransactionType.WRITE_ONLY;
 import akka.actor.ActorRef;
 import akka.actor.ActorSelection;
 import akka.actor.ActorSystem;
 import akka.actor.Props;
 import akka.dispatch.Futures;
+import akka.util.Timeout;
 import com.google.common.base.Optional;
+import com.google.common.collect.Sets;
 import com.google.common.util.concurrent.CheckedFuture;
 import com.google.common.util.concurrent.FutureCallback;
 import com.google.common.util.concurrent.Uninterruptibles;
+import java.util.Collection;
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 import org.junit.Assert;
 import org.junit.Test;
 import org.mockito.InOrder;
 import org.mockito.Mockito;
+import org.opendaylight.controller.cluster.access.concepts.MemberName;
+import org.opendaylight.controller.cluster.datastore.config.Configuration;
+import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
+import org.opendaylight.controller.cluster.datastore.exceptions.NotInitializedException;
 import org.opendaylight.controller.cluster.datastore.exceptions.PrimaryNotFoundException;
 import org.opendaylight.controller.cluster.datastore.exceptions.TimeoutException;
 import org.opendaylight.controller.cluster.datastore.messages.BatchedModifications;
-import org.opendaylight.controller.cluster.datastore.messages.BatchedModificationsReply;
 import org.opendaylight.controller.cluster.datastore.messages.CloseTransaction;
-import org.opendaylight.controller.cluster.datastore.messages.ReadyTransaction;
+import org.opendaylight.controller.cluster.datastore.messages.CommitTransactionReply;
+import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
+import org.opendaylight.controller.cluster.datastore.messages.PrimaryShardInfo;
 import org.opendaylight.controller.cluster.datastore.modification.DeleteModification;
 import org.opendaylight.controller.cluster.datastore.modification.MergeModification;
 import org.opendaylight.controller.cluster.datastore.modification.WriteModification;
 import org.opendaylight.controller.cluster.datastore.shardstrategy.DefaultShardStrategy;
-import org.opendaylight.controller.cluster.datastore.utils.DoNothingActor;
+import org.opendaylight.controller.cluster.datastore.utils.NormalizedNodeAggregatorTest;
+import org.opendaylight.controller.cluster.raft.utils.DoNothingActor;
 import org.opendaylight.controller.md.cluster.datastore.model.CarsModel;
+import org.opendaylight.controller.md.cluster.datastore.model.SchemaContextHelper;
 import org.opendaylight.controller.md.cluster.datastore.model.TestModel;
 import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
-import org.opendaylight.controller.protobuff.messages.transaction.ShardTransactionMessages.CreateTransactionReply;
 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot;
 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
-import scala.concurrent.Await;
-import scala.concurrent.Future;
+import org.opendaylight.yangtools.yang.model.api.SchemaContext;
 import scala.concurrent.Promise;
-import scala.concurrent.duration.Duration;
 
 @SuppressWarnings("resource")
 public class TransactionProxyTest extends AbstractTransactionProxyTest {
@@ -70,10 +90,10 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
     public void testRead() throws Exception {
         ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
 
-        doReturn(readSerializedDataReply(null)).when(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedReadData());
+        doReturn(readDataReply(null)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqReadData(), any(Timeout.class));
 
         Optional<NormalizedNode<?, ?>> readOptional = transactionProxy.read(
                 TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);
@@ -82,8 +102,8 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
         NormalizedNode<?, ?> expectedNode = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
-        doReturn(readSerializedDataReply(expectedNode)).when(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedReadData());
+        doReturn(readDataReply(expectedNode)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqReadData(), any(Timeout.class));
 
         readOptional = transactionProxy.read(TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);
 
@@ -97,9 +117,9 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
         ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
 
         doReturn(Futures.successful(new Object())).when(mockActorContext).
-                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedReadData());
+                executeOperationAsync(eq(actorSelection(actorRef)), eqReadData(), any(Timeout.class));
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
 
         transactionProxy.read(TestModel.TEST_PATH).checkedGet(5, TimeUnit.SECONDS);
     }
@@ -109,9 +129,9 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
         ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
 
         doReturn(Futures.failed(new TestException())).when(mockActorContext).
-                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedReadData());
+                executeOperationAsync(eq(actorSelection(actorRef)), eqReadData(), any(Timeout.class));
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
 
         propagateReadFailedExceptionCause(transactionProxy.read(TestModel.TEST_PATH));
     }
@@ -123,14 +143,14 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
         if (exToThrow instanceof PrimaryNotFoundException) {
             doReturn(Futures.failed(exToThrow)).when(mockActorContext).findPrimaryShardAsync(anyString());
         } else {
-            doReturn(Futures.successful(getSystem().actorSelection(actorRef.path()))).
+            doReturn(primaryShardInfoReply(getSystem(), actorRef)).
                     when(mockActorContext).findPrimaryShardAsync(anyString());
         }
 
         doReturn(Futures.failed(exToThrow)).when(mockActorContext).executeOperationAsync(
-                any(ActorSelection.class), any());
+                any(ActorSelection.class), any(), any(Timeout.class));
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
 
         propagateReadFailedExceptionCause(invoker.invoke(transactionProxy));
     }
@@ -160,34 +180,6 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
         testReadWithExceptionOnInitialCreateTransaction(new TestException());
     }
 
-    @Test(expected = TestException.class)
-    public void testReadWithPriorRecordingOperationFailure() throws Throwable {
-        doReturn(dataStoreContextBuilder.shardBatchedModificationCount(2).build()).
-                when(mockActorContext).getDatastoreContext();
-
-        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
-
-        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
-
-        expectFailedBatchedModifications(actorRef);
-
-        doReturn(readSerializedDataReply(null)).when(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedReadData());
-
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_WRITE);
-
-        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
-
-        transactionProxy.delete(TestModel.TEST_PATH);
-
-        try {
-            propagateReadFailedExceptionCause(transactionProxy.read(TestModel.TEST_PATH));
-        } finally {
-            verify(mockActorContext, times(0)).executeOperationAsync(
-                    eq(actorSelection(actorRef)), eqSerializedReadData());
-        }
-    }
-
     @Test
     public void testReadWithPriorRecordingOperationSuccessful() throws Throwable {
         ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
@@ -196,10 +188,10 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
         expectBatchedModifications(actorRef, 1);
 
-        doReturn(readSerializedDataReply(expectedNode)).when(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedReadData());
+        doReturn(readDataReply(expectedNode)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqReadData(), any(Timeout.class));
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_WRITE);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
 
         transactionProxy.write(TestModel.TEST_PATH, expectedNode);
 
@@ -211,15 +203,15 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
         InOrder inOrder = Mockito.inOrder(mockActorContext);
         inOrder.verify(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), isA(BatchedModifications.class));
+                eq(actorSelection(actorRef)), isA(BatchedModifications.class), any(Timeout.class));
 
         inOrder.verify(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedReadData());
+                eq(actorSelection(actorRef)), eqReadData(), any(Timeout.class));
     }
 
     @Test(expected=IllegalStateException.class)
     public void testReadPreConditionCheck() {
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, WRITE_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
         transactionProxy.read(TestModel.TEST_PATH);
     }
 
@@ -230,13 +222,14 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
         doReturn(getSystem().actorSelection(actorRef.path())).when(mockActorContext).
             actorSelection(actorRef.path().toString());
 
-        doReturn(Futures.successful(getSystem().actorSelection(actorRef.path()))).
+        doReturn(primaryShardInfoReply(getSystem(), actorRef)).
             when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
 
         doReturn(Futures.successful(new Object())).when(mockActorContext).executeOperationAsync(
-            eq(getSystem().actorSelection(actorRef.path())), eqCreateTransaction(memberName, READ_ONLY));
+            eq(getSystem().actorSelection(actorRef.path())), eqCreateTransaction(memberName, READ_ONLY),
+            any(Timeout.class));
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
 
         propagateReadFailedExceptionCause(transactionProxy.read(TestModel.TEST_PATH));
     }
@@ -245,17 +238,17 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
     public void testExists() throws Exception {
         ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
 
-        doReturn(dataExistsSerializedReply(false)).when(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedDataExists());
+        doReturn(dataExistsReply(false)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqDataExists(), any(Timeout.class));
 
         Boolean exists = transactionProxy.exists(TestModel.TEST_PATH).checkedGet();
 
         assertEquals("Exists response", false, exists);
 
-        doReturn(dataExistsSerializedReply(true)).when(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedDataExists());
+        doReturn(dataExistsReply(true)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqDataExists(), any(Timeout.class));
 
         exists = transactionProxy.exists(TestModel.TEST_PATH).checkedGet();
 
@@ -277,10 +270,9 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
         ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
 
         doReturn(Futures.successful(new Object())).when(mockActorContext).
-                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedDataExists());
+                executeOperationAsync(eq(actorSelection(actorRef)), eqDataExists(), any(Timeout.class));
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
-                READ_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
 
         transactionProxy.exists(TestModel.TEST_PATH).checkedGet(5, TimeUnit.SECONDS);
     }
@@ -290,42 +282,13 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
         ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
 
         doReturn(Futures.failed(new TestException())).when(mockActorContext).
-                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedDataExists());
+                executeOperationAsync(eq(actorSelection(actorRef)), eqDataExists(), any(Timeout.class));
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
 
         propagateReadFailedExceptionCause(transactionProxy.exists(TestModel.TEST_PATH));
     }
 
-    @Test(expected = TestException.class)
-    public void testExistsWithPriorRecordingOperationFailure() throws Throwable {
-        doReturn(dataStoreContextBuilder.shardBatchedModificationCount(2).build()).
-                when(mockActorContext).getDatastoreContext();
-
-        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
-
-        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
-
-        expectFailedBatchedModifications(actorRef);
-
-        doReturn(dataExistsSerializedReply(false)).when(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedDataExists());
-
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
-                READ_WRITE);
-
-        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
-
-        transactionProxy.delete(TestModel.TEST_PATH);
-
-        try {
-            propagateReadFailedExceptionCause(transactionProxy.exists(TestModel.TEST_PATH));
-        } finally {
-            verify(mockActorContext, times(0)).executeOperationAsync(
-                    eq(actorSelection(actorRef)), eqSerializedDataExists());
-        }
-    }
-
     @Test
     public void testExistsWithPriorRecordingOperationSuccessful() throws Throwable {
         ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
@@ -334,10 +297,10 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
         expectBatchedModifications(actorRef, 1);
 
-        doReturn(dataExistsSerializedReply(true)).when(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedDataExists());
+        doReturn(dataExistsReply(true)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqDataExists(), any(Timeout.class));
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_WRITE);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
 
         transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
 
@@ -347,81 +310,51 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
         InOrder inOrder = Mockito.inOrder(mockActorContext);
         inOrder.verify(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), isA(BatchedModifications.class));
+                eq(actorSelection(actorRef)), isA(BatchedModifications.class), any(Timeout.class));
 
         inOrder.verify(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedDataExists());
+                eq(actorSelection(actorRef)), eqDataExists(), any(Timeout.class));
     }
 
     @Test(expected=IllegalStateException.class)
     public void testExistsPreConditionCheck() {
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, WRITE_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
         transactionProxy.exists(TestModel.TEST_PATH);
     }
 
-    private void verifyRecordingOperationFutures(List<Future<Object>> futures,
-            Class<?>... expResultTypes) throws Exception {
-        assertEquals("getRecordingOperationFutures size", expResultTypes.length, futures.size());
-
-        int i = 0;
-        for( Future<Object> future: futures) {
-            assertNotNull("Recording operation Future is null", future);
-
-            Class<?> expResultType = expResultTypes[i++];
-            if(Throwable.class.isAssignableFrom(expResultType)) {
-                try {
-                    Await.result(future, Duration.create(5, TimeUnit.SECONDS));
-                    fail("Expected exception from recording operation Future");
-                } catch(Exception e) {
-                    // Expected
-                }
-            } else {
-                assertEquals(String.format("Recording operation %d Future result type", i +1 ), expResultType,
-                             Await.result(future, Duration.create(5, TimeUnit.SECONDS)).getClass());
-            }
-        }
-    }
-
     @Test
     public void testWrite() throws Exception {
+        dataStoreContextBuilder.shardBatchedModificationCount(1);
         ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
 
         NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
         expectBatchedModifications(actorRef, 1);
-        expectReadyTransaction(actorRef);
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, WRITE_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
         transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
 
-        // This sends the batched modification.
-        transactionProxy.ready();
-
-        verifyOneBatchedModification(actorRef, new WriteModification(TestModel.TEST_PATH, nodeToWrite));
-
-        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
-                BatchedModificationsReply.class);
+        verifyOneBatchedModification(actorRef, new WriteModification(TestModel.TEST_PATH, nodeToWrite), false);
     }
 
     @Test
     public void testWriteAfterAsyncRead() throws Throwable {
-        ActorRef actorRef = setupActorContextWithoutInitialCreateTransaction(getSystem());
+        ActorRef actorRef = setupActorContextWithoutInitialCreateTransaction(getSystem(), DefaultShardStrategy.DEFAULT_SHARD);
 
         Promise<Object> createTxPromise = akka.dispatch.Futures.promise();
         doReturn(createTxPromise).when(mockActorContext).executeOperationAsync(
                 eq(getSystem().actorSelection(actorRef.path())),
-                eqCreateTransaction(memberName, READ_WRITE));
+                eqCreateTransaction(memberName, READ_WRITE), any(Timeout.class));
 
-        doReturn(readSerializedDataReply(null)).when(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedReadData());
+        doReturn(readDataReply(null)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqReadData(), any(Timeout.class));
 
-        expectBatchedModifications(actorRef, 1);
-        expectReadyTransaction(actorRef);
+        expectBatchedModificationsReady(actorRef);
 
         final NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
-        final TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_WRITE);
+        final TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
 
         final CountDownLatch readComplete = new CountDownLatch(1);
         final AtomicReference<Throwable> caughtEx = new AtomicReference<>();
@@ -456,21 +389,18 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
         // This sends the batched modification.
         transactionProxy.ready();
 
-        verifyOneBatchedModification(actorRef, new WriteModification(TestModel.TEST_PATH, nodeToWrite));
-
-        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
-                BatchedModificationsReply.class);
+        verifyOneBatchedModification(actorRef, new WriteModification(TestModel.TEST_PATH, nodeToWrite), true);
     }
 
     @Test(expected=IllegalStateException.class)
     public void testWritePreConditionCheck() {
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
         transactionProxy.write(TestModel.TEST_PATH, ImmutableNodes.containerNode(TestModel.TEST_QNAME));
     }
 
     @Test(expected=IllegalStateException.class)
     public void testWriteAfterReadyPreConditionCheck() {
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, WRITE_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
         transactionProxy.ready();
 
@@ -479,333 +409,370 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
     @Test
     public void testMerge() throws Exception {
+        dataStoreContextBuilder.shardBatchedModificationCount(1);
         ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
 
         NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
         expectBatchedModifications(actorRef, 1);
-        expectReadyTransaction(actorRef);
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, WRITE_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
         transactionProxy.merge(TestModel.TEST_PATH, nodeToWrite);
 
-        // This sends the batched modification.
-        transactionProxy.ready();
-
-        verifyOneBatchedModification(actorRef, new MergeModification(TestModel.TEST_PATH, nodeToWrite));
-
-        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
-                BatchedModificationsReply.class);
+        verifyOneBatchedModification(actorRef, new MergeModification(TestModel.TEST_PATH, nodeToWrite), false);
     }
 
     @Test
     public void testDelete() throws Exception {
+        dataStoreContextBuilder.shardBatchedModificationCount(1);
         ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
 
         expectBatchedModifications(actorRef, 1);
-        expectReadyTransaction(actorRef);
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, WRITE_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
         transactionProxy.delete(TestModel.TEST_PATH);
 
-        // This sends the batched modification.
-        transactionProxy.ready();
-
-        verifyOneBatchedModification(actorRef, new DeleteModification(TestModel.TEST_PATH));
-
-        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
-                BatchedModificationsReply.class);
+        verifyOneBatchedModification(actorRef, new DeleteModification(TestModel.TEST_PATH), false);
     }
 
     @Test
-    public void testReady() throws Exception {
+    public void testReadWrite() throws Exception {
         ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
 
         NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
-        doReturn(readSerializedDataReply(null)).when(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedReadData());
+        doReturn(readDataReply(null)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqReadData(), any(Timeout.class));
 
         expectBatchedModifications(actorRef, 1);
-        expectReadyTransaction(actorRef);
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_WRITE);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
 
         transactionProxy.read(TestModel.TEST_PATH);
 
         transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
 
-        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
-
-        assertTrue(ready instanceof ThreePhaseCommitCohortProxy);
-
-        ThreePhaseCommitCohortProxy proxy = (ThreePhaseCommitCohortProxy) ready;
+        transactionProxy.read(TestModel.TEST_PATH);
 
-        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
-                BatchedModificationsReply.class);
+        transactionProxy.read(TestModel.TEST_PATH);
 
-        verifyCohortFutures(proxy, getSystem().actorSelection(actorRef.path()));
+        List<BatchedModifications> batchedModifications = captureBatchedModifications(actorRef);
+        assertEquals("Captured BatchedModifications count", 1, batchedModifications.size());
 
-        verify(mockActorContext).executeOperationAsync(eq(actorSelection(actorRef)),
-                isA(BatchedModifications.class));
+        verifyBatchedModifications(batchedModifications.get(0), false,
+                new WriteModification(TestModel.TEST_PATH, nodeToWrite));
     }
 
     @Test
-    public void testReadyWithRecordingOperationFailure() throws Exception {
-        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
+    public void testReadyWithReadWrite() throws Exception {
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
 
         NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
-        expectFailedBatchedModifications(actorRef);
+        doReturn(readDataReply(null)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqReadData(), any(Timeout.class));
 
-        expectReadyTransaction(actorRef);
+        expectBatchedModificationsReady(actorRef, true);
 
-        doReturn(false).when(mockActorContext).isPathLocal(actorRef.path().toString());
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, WRITE_ONLY);
+        transactionProxy.read(TestModel.TEST_PATH);
 
         transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
 
         DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
 
-        assertTrue(ready instanceof ThreePhaseCommitCohortProxy);
+        assertTrue(ready instanceof SingleCommitCohortProxy);
+
+        verifyCohortFutures((SingleCommitCohortProxy)ready, new CommitTransactionReply().toSerializable());
 
-        ThreePhaseCommitCohortProxy proxy = (ThreePhaseCommitCohortProxy) ready;
+        List<BatchedModifications> batchedModifications = captureBatchedModifications(actorRef);
+        assertEquals("Captured BatchedModifications count", 1, batchedModifications.size());
 
-        verifyCohortFutures(proxy, TestException.class);
+        verifyBatchedModifications(batchedModifications.get(0), true, true,
+                new WriteModification(TestModel.TEST_PATH, nodeToWrite));
 
-        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(), TestException.class);
+        assertEquals("getTotalMessageCount", 1, batchedModifications.get(0).getTotalMessagesSent());
     }
 
     @Test
-    public void testReadyWithReplyFailure() throws Exception {
-        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
-
-        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+    public void testReadyWithNoModifications() throws Exception {
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
 
-        expectBatchedModifications(actorRef, 1);
+        doReturn(readDataReply(null)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqReadData(), any(Timeout.class));
 
-        doReturn(Futures.failed(new TestException())).when(mockActorContext).
-                executeOperationAsync(eq(actorSelection(actorRef)),
-                        isA(ReadyTransaction.SERIALIZABLE_CLASS));
+        expectBatchedModificationsReady(actorRef, true);
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, WRITE_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
 
-        transactionProxy.merge(TestModel.TEST_PATH, nodeToWrite);
+        transactionProxy.read(TestModel.TEST_PATH);
 
         DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
 
-        assertTrue(ready instanceof ThreePhaseCommitCohortProxy);
+        assertTrue(ready instanceof SingleCommitCohortProxy);
 
-        ThreePhaseCommitCohortProxy proxy = (ThreePhaseCommitCohortProxy) ready;
+        verifyCohortFutures((SingleCommitCohortProxy)ready, new CommitTransactionReply().toSerializable());
 
-        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
-                BatchedModificationsReply.class);
+        List<BatchedModifications> batchedModifications = captureBatchedModifications(actorRef);
+        assertEquals("Captured BatchedModifications count", 1, batchedModifications.size());
 
-        verifyCohortFutures(proxy, TestException.class);
+        verifyBatchedModifications(batchedModifications.get(0), true, true);
     }
 
     @Test
-    public void testReadyWithInitialCreateTransactionFailure() throws Exception {
+    public void testReadyWithMultipleShardWrites() throws Exception {
+        ActorRef actorRef1 = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
+
+        ActorRef actorRef2 = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY, "junk");
+
+        expectBatchedModificationsReady(actorRef1);
+        expectBatchedModificationsReady(actorRef2);
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
+
+        transactionProxy.write(TestModel.JUNK_PATH, ImmutableNodes.containerNode(TestModel.JUNK_QNAME));
+        transactionProxy.write(TestModel.TEST_PATH, ImmutableNodes.containerNode(TestModel.TEST_QNAME));
+
+        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
+
+        assertTrue(ready instanceof ThreePhaseCommitCohortProxy);
+
+        verifyCohortFutures((ThreePhaseCommitCohortProxy)ready, actorSelection(actorRef1),
+                actorSelection(actorRef2));
+    }
 
-        doReturn(Futures.failed(new PrimaryNotFoundException("mock"))).when(
-                mockActorContext).findPrimaryShardAsync(anyString());
+    @Test
+    public void testReadyWithWriteOnlyAndLastBatchPending() throws Exception {
+        dataStoreContextBuilder.writeOnlyTransactionOptimizationsEnabled(true);
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, WRITE_ONLY);
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
 
         NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
-        transactionProxy.merge(TestModel.TEST_PATH, nodeToWrite);
+        expectBatchedModificationsReady(actorRef, true);
 
-        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
-        transactionProxy.delete(TestModel.TEST_PATH);
+        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
 
         DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
 
-        assertTrue(ready instanceof ThreePhaseCommitCohortProxy);
+        assertTrue(ready instanceof SingleCommitCohortProxy);
+
+        verifyCohortFutures((SingleCommitCohortProxy)ready, new CommitTransactionReply().toSerializable());
 
-        ThreePhaseCommitCohortProxy proxy = (ThreePhaseCommitCohortProxy) ready;
+        List<BatchedModifications> batchedModifications = captureBatchedModifications(actorRef);
+        assertEquals("Captured BatchedModifications count", 1, batchedModifications.size());
 
-        verifyCohortFutures(proxy, PrimaryNotFoundException.class);
+        verifyBatchedModifications(batchedModifications.get(0), true, true,
+                new WriteModification(TestModel.TEST_PATH, nodeToWrite));
     }
 
     @Test
-    public void testReadyWithInvalidReplyMessageType() throws Exception {
+    public void testReadyWithWriteOnlyAndLastBatchEmpty() throws Exception {
+        dataStoreContextBuilder.shardBatchedModificationCount(1).writeOnlyTransactionOptimizationsEnabled(true);
         ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
 
         NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
-        expectBatchedModifications(actorRef, 1);
-
-        doReturn(Futures.successful(new Object())).when(mockActorContext).
-                executeOperationAsync(eq(actorSelection(actorRef)),
-                        isA(ReadyTransaction.SERIALIZABLE_CLASS));
+        expectBatchedModificationsReady(actorRef, true);
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, WRITE_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
         transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
 
         DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
 
-        assertTrue(ready instanceof ThreePhaseCommitCohortProxy);
+        assertTrue(ready instanceof SingleCommitCohortProxy);
+
+        verifyCohortFutures((SingleCommitCohortProxy)ready, new CommitTransactionReply().toSerializable());
 
-        ThreePhaseCommitCohortProxy proxy = (ThreePhaseCommitCohortProxy) ready;
+        List<BatchedModifications> batchedModifications = captureBatchedModifications(actorRef);
+        assertEquals("Captured BatchedModifications count", 2, batchedModifications.size());
+
+        verifyBatchedModifications(batchedModifications.get(0), false,
+                new WriteModification(TestModel.TEST_PATH, nodeToWrite));
 
-        verifyCohortFutures(proxy, IllegalArgumentException.class);
+        verifyBatchedModifications(batchedModifications.get(1), true, true);
     }
 
     @Test
-    public void testUnusedTransaction() throws Exception {
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_WRITE);
+    public void testReadyWithReplyFailure() throws Exception {
+        dataStoreContextBuilder.writeOnlyTransactionOptimizationsEnabled(true);
+
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
+
+        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+        expectFailedBatchedModifications(actorRef);
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
+
+        transactionProxy.merge(TestModel.TEST_PATH, nodeToWrite);
 
         DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
 
-        assertEquals("canCommit", true, ready.canCommit().get());
-        ready.preCommit().get();
-        ready.commit().get();
+        assertTrue(ready instanceof SingleCommitCohortProxy);
+
+        verifyCohortFutures((SingleCommitCohortProxy)ready, TestException.class);
     }
 
     @Test
-    public void testGetIdentifier() {
-        setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
-                TransactionProxy.TransactionType.READ_ONLY);
+    public void testReadyWithDebugContextEnabled() throws Exception {
+        dataStoreContextBuilder.transactionDebugContextEnabled(true);
 
-        Object id = transactionProxy.getIdentifier();
-        assertNotNull("getIdentifier returned null", id);
-        assertTrue("Invalid identifier: " + id, id.toString().startsWith(memberName));
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
+
+        expectBatchedModificationsReady(actorRef, true);
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
+
+        transactionProxy.merge(TestModel.TEST_PATH, ImmutableNodes.containerNode(TestModel.TEST_QNAME));
+
+        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
+
+        assertTrue(ready instanceof DebugThreePhaseCommitCohort);
+
+        verifyCohortFutures((DebugThreePhaseCommitCohort)ready, new CommitTransactionReply().toSerializable());
     }
 
     @Test
-    public void testClose() throws Exception{
-        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
+    public void testReadyWithLocalTransaction() throws Exception {
+        ActorRef shardActorRef = getSystem().actorOf(Props.create(DoNothingActor.class));
 
-        doReturn(readSerializedDataReply(null)).when(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedReadData());
+        doReturn(getSystem().actorSelection(shardActorRef.path())).
+                when(mockActorContext).actorSelection(shardActorRef.path().toString());
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_WRITE);
+        doReturn(Futures.successful(newPrimaryShardInfo(shardActorRef, createDataTree()))).
+                when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
 
-        transactionProxy.read(TestModel.TEST_PATH);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
-        transactionProxy.close();
+        expectReadyLocalTransaction(shardActorRef, true);
+
+        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+
+        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
+        assertTrue(ready instanceof SingleCommitCohortProxy);
+        verifyCohortFutures((SingleCommitCohortProxy)ready, new CommitTransactionReply().toSerializable());
+    }
 
-        verify(mockActorContext).sendOperationAsync(
-                eq(actorSelection(actorRef)), isA(CloseTransaction.SERIALIZABLE_CLASS));
-    }
-
-
-    /**
-     * Method to test a local Tx actor. The Tx paths are matched to decide if the
-     * Tx actor is local or not. This is done by mocking the Tx actor path
-     * and the caller paths and ensuring that the paths have the remote-address format
-     *
-     * Note: Since the default akka provider for test is not a RemoteActorRefProvider,
-     * the paths returned for the actors for all the tests are not qualified remote paths.
-     * Hence are treated as non-local/remote actors. In short, all tests except
-     * few below run for remote actors
-     *
-     * @throws Exception
-     */
     @Test
-    public void testLocalTxActorRead() throws Exception {
-        ActorSystem actorSystem = getSystem();
-        ActorRef shardActorRef = actorSystem.actorOf(Props.create(DoNothingActor.class));
+    public void testReadyWithLocalTransactionWithFailure() throws Exception {
+        ActorRef shardActorRef = getSystem().actorOf(Props.create(DoNothingActor.class));
 
-        doReturn(actorSystem.actorSelection(shardActorRef.path())).
-            when(mockActorContext).actorSelection(shardActorRef.path().toString());
+        doReturn(getSystem().actorSelection(shardActorRef.path())).
+                when(mockActorContext).actorSelection(shardActorRef.path().toString());
 
-        doReturn(Futures.successful(actorSystem.actorSelection(shardActorRef.path()))).
-            when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
+        DataTree mockDataTree = createDataTree();
+        DataTreeModification mockModification = mockDataTree.takeSnapshot().newModification();
+        doThrow(new RuntimeException("mock")).when(mockModification).ready();
 
-        String actorPath = "akka.tcp://system@127.0.0.1:2550/user/tx-actor";
-        CreateTransactionReply createTransactionReply = CreateTransactionReply.newBuilder()
-            .setTransactionId("txn-1").setTransactionActorPath(actorPath).build();
+        doReturn(Futures.successful(newPrimaryShardInfo(shardActorRef, mockDataTree))).
+                when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
 
-        doReturn(Futures.successful(createTransactionReply)).when(mockActorContext).
-            executeOperationAsync(eq(actorSystem.actorSelection(shardActorRef.path())),
-                eqCreateTransaction(memberName, READ_ONLY));
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
-        doReturn(true).when(mockActorContext).isPathLocal(actorPath);
+        expectReadyLocalTransaction(shardActorRef, true);
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,READ_ONLY);
+        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
 
-        // negative test case with null as the reply
-        doReturn(readDataReply(null)).when(mockActorContext).executeOperationAsync(
-            any(ActorSelection.class), eqReadData());
+        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
+        assertTrue(ready instanceof SingleCommitCohortProxy);
+        verifyCohortFutures((SingleCommitCohortProxy)ready, RuntimeException.class);
+    }
 
-        Optional<NormalizedNode<?, ?>> readOptional = transactionProxy.read(
-            TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);
+    private void testWriteOnlyTxWithFindPrimaryShardFailure(Exception toThrow) throws Exception {
+        doReturn(Futures.failed(toThrow)).when(mockActorContext).findPrimaryShardAsync(anyString());
 
-        assertEquals("NormalizedNode isPresent", false, readOptional.isPresent());
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
-        // test case with node as read data reply
-        NormalizedNode<?, ?> expectedNode = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
-        doReturn(readDataReply(expectedNode)).when(mockActorContext).executeOperationAsync(
-            any(ActorSelection.class), eqReadData());
+        transactionProxy.merge(TestModel.TEST_PATH, nodeToWrite);
 
-        readOptional = transactionProxy.read(TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);
+        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
 
-        assertEquals("NormalizedNode isPresent", true, readOptional.isPresent());
+        transactionProxy.delete(TestModel.TEST_PATH);
 
-        assertEquals("Response NormalizedNode", expectedNode, readOptional.get());
+        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
 
-        // test for local data exists
-        doReturn(dataExistsReply(true)).when(mockActorContext).executeOperationAsync(
-            any(ActorSelection.class), eqDataExists());
+        assertTrue(ready instanceof SingleCommitCohortProxy);
 
-        boolean exists = transactionProxy.exists(TestModel.TEST_PATH).checkedGet();
+        verifyCohortFutures((SingleCommitCohortProxy)ready, toThrow.getClass());
+    }
 
-        assertEquals("Exists response", true, exists);
+    @Test
+    public void testWriteOnlyTxWithPrimaryNotFoundException() throws Exception {
+        testWriteOnlyTxWithFindPrimaryShardFailure(new PrimaryNotFoundException("mock"));
     }
 
     @Test
-    public void testLocalTxActorReady() throws Exception {
-        ActorSystem actorSystem = getSystem();
-        ActorRef shardActorRef = actorSystem.actorOf(Props.create(DoNothingActor.class));
+    public void testWriteOnlyTxWithNotInitializedException() throws Exception {
+        testWriteOnlyTxWithFindPrimaryShardFailure(new NotInitializedException("mock"));
+    }
 
-        doReturn(actorSystem.actorSelection(shardActorRef.path())).
-            when(mockActorContext).actorSelection(shardActorRef.path().toString());
+    @Test
+    public void testWriteOnlyTxWithNoShardLeaderException() throws Exception {
+        testWriteOnlyTxWithFindPrimaryShardFailure(new NoShardLeaderException("mock"));
+    }
 
-        doReturn(Futures.successful(actorSystem.actorSelection(shardActorRef.path()))).
-            when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
+    @Test
+    public void testReadyWithInvalidReplyMessageType() throws Exception {
+        dataStoreContextBuilder.writeOnlyTransactionOptimizationsEnabled(true);
+        ActorRef actorRef1 = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
 
-        String actorPath = "akka.tcp://system@127.0.0.1:2550/user/tx-actor";
-        CreateTransactionReply createTransactionReply = CreateTransactionReply.newBuilder().
-            setTransactionId("txn-1").setTransactionActorPath(actorPath).
-            setMessageVersion(DataStoreVersions.CURRENT_VERSION).build();
+        ActorRef actorRef2 = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY, "junk");
 
-        doReturn(Futures.successful(createTransactionReply)).when(mockActorContext).
-            executeOperationAsync(eq(actorSystem.actorSelection(shardActorRef.path())),
-                eqCreateTransaction(memberName, WRITE_ONLY));
+        doReturn(Futures.successful(new Object())).when(mockActorContext).
+                executeOperationAsync(eq(actorSelection(actorRef1)), isA(BatchedModifications.class),
+                        any(Timeout.class));
 
-        doReturn(true).when(mockActorContext).isPathLocal(actorPath);
+        expectBatchedModificationsReady(actorRef2);
 
-        doReturn(batchedModificationsReply(1)).when(mockActorContext).executeOperationAsync(
-                any(ActorSelection.class), isA(BatchedModifications.class));
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, WRITE_ONLY);
+        transactionProxy.write(TestModel.JUNK_PATH, ImmutableNodes.containerNode(TestModel.JUNK_QNAME));
+        transactionProxy.write(TestModel.TEST_PATH, ImmutableNodes.containerNode(TestModel.TEST_QNAME));
 
-        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
-        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
 
-        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
-                BatchedModificationsReply.class);
+        assertTrue(ready instanceof ThreePhaseCommitCohortProxy);
 
-        // testing ready
-        doReturn(readyTxReply(shardActorRef.path().toString())).when(mockActorContext).executeOperationAsync(
-            any(ActorSelection.class), isA(ReadyTransaction.class));
+        verifyCohortFutures((ThreePhaseCommitCohortProxy)ready, actorSelection(actorRef2),
+                IllegalArgumentException.class);
+    }
 
-        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
+    @Test
+    public void testGetIdentifier() {
+        setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
 
-        assertTrue(ready instanceof ThreePhaseCommitCohortProxy);
+        Object id = transactionProxy.getIdentifier();
+        assertNotNull("getIdentifier returned null", id);
+        assertTrue("Invalid identifier: " + id, id.toString().startsWith(memberName));
+    }
+
+    @Test
+    public void testClose() throws Exception{
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
+
+        doReturn(readDataReply(null)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqReadData(), any(Timeout.class));
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
+
+        transactionProxy.read(TestModel.TEST_PATH);
 
-        ThreePhaseCommitCohortProxy proxy = (ThreePhaseCommitCohortProxy) ready;
+        transactionProxy.close();
 
-        verifyCohortFutures(proxy, getSystem().actorSelection(shardActorRef.path()));
+        verify(mockActorContext).sendOperationAsync(
+                eq(actorSelection(actorRef)), isA(CloseTransaction.class));
     }
 
     private static interface TransactionProxyOperation {
@@ -817,34 +784,50 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
     }
 
     private void throttleOperation(TransactionProxyOperation operation, int outstandingOpsLimit, boolean shardFound){
+        throttleOperation(operation, outstandingOpsLimit, shardFound, TimeUnit.MILLISECONDS.toNanos(
+                mockActorContext.getDatastoreContext().getOperationTimeoutInMillis()));
+    }
+
+    private PrimaryShardInfo newPrimaryShardInfo(ActorRef actorRef){
+        return new PrimaryShardInfo(getSystem().actorSelection(actorRef.path()), DataStoreVersions.CURRENT_VERSION);
+    }
+
+    private PrimaryShardInfo newPrimaryShardInfo(ActorRef actorRef, DataTree dataTree){
+        return new PrimaryShardInfo(getSystem().actorSelection(actorRef.path()), DataStoreVersions.CURRENT_VERSION,
+                dataTree);
+    }
+
+
+    private void throttleOperation(TransactionProxyOperation operation, int outstandingOpsLimit, boolean shardFound, long expectedCompletionTime){
         ActorSystem actorSystem = getSystem();
         ActorRef shardActorRef = actorSystem.actorOf(Props.create(DoNothingActor.class));
 
-        doReturn(outstandingOpsLimit).when(mockActorContext).getTransactionOutstandingOperationLimit();
+        // Note that we setting batchedModificationCount to one less than what we need because in TransactionProxy
+        // we now allow one extra permit to be allowed for ready
+        doReturn(dataStoreContextBuilder.operationTimeoutInSeconds(2).
+                shardBatchedModificationCount(outstandingOpsLimit-1).build()).when(mockActorContext).getDatastoreContext();
 
         doReturn(actorSystem.actorSelection(shardActorRef.path())).
                 when(mockActorContext).actorSelection(shardActorRef.path().toString());
 
         if(shardFound) {
-            doReturn(Futures.successful(actorSystem.actorSelection(shardActorRef.path()))).
+            doReturn(Futures.successful(newPrimaryShardInfo(shardActorRef))).
                     when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
+            doReturn(Futures.successful(newPrimaryShardInfo(shardActorRef))).
+                    when(mockActorContext).findPrimaryShardAsync(eq("cars"));
+
         } else {
             doReturn(Futures.failed(new Exception("not found")))
                     .when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
         }
 
         String actorPath = "akka.tcp://system@127.0.0.1:2550/user/tx-actor";
-        CreateTransactionReply createTransactionReply = CreateTransactionReply.newBuilder().
-                setTransactionId("txn-1").setTransactionActorPath(actorPath).
-                setMessageVersion(DataStoreVersions.CURRENT_VERSION).build();
-
-        doReturn(Futures.successful(createTransactionReply)).when(mockActorContext).
-                executeOperationAsync(eq(actorSystem.actorSelection(shardActorRef.path())),
-                        eqCreateTransaction(memberName, READ_WRITE));
 
-        doReturn(true).when(mockActorContext).isPathLocal(actorPath);
+        doReturn(incompleteFuture()).when(mockActorContext).
+        executeOperationAsync(eq(actorSystem.actorSelection(shardActorRef.path())),
+                 eqCreateTransaction(memberName, READ_WRITE), any(Timeout.class));
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_WRITE);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
 
         long start = System.nanoTime();
 
@@ -852,9 +835,9 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
         long end = System.nanoTime();
 
-        long expected = TimeUnit.SECONDS.toNanos(mockActorContext.getDatastoreContext().getOperationTimeoutInSeconds());
         Assert.assertTrue(String.format("Expected elapsed time: %s. Actual: %s",
-                expected, (end-start)), (end - start) > expected);
+                expectedCompletionTime, (end-start)),
+                ((end - start) > expectedCompletionTime) && ((end - start) < expectedCompletionTime*2));
 
     }
 
@@ -866,31 +849,52 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
         ActorSystem actorSystem = getSystem();
         ActorRef shardActorRef = actorSystem.actorOf(Props.create(DoNothingActor.class));
 
-        doReturn(1).when(mockActorContext).getTransactionOutstandingOperationLimit();
-
         doReturn(actorSystem.actorSelection(shardActorRef.path())).
                 when(mockActorContext).actorSelection(shardActorRef.path().toString());
 
         if(shardFound) {
-            doReturn(Futures.successful(actorSystem.actorSelection(shardActorRef.path()))).
+            doReturn(Futures.successful(newPrimaryShardInfo(shardActorRef))).
                     when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
         } else {
-            doReturn(Futures.failed(new Exception("not found")))
+            doReturn(Futures.failed(new PrimaryNotFoundException("test")))
                     .when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
         }
 
-        String actorPath = "akka.tcp://system@127.0.0.1:2550/user/tx-actor";
-        CreateTransactionReply createTransactionReply = CreateTransactionReply.newBuilder().
-                setTransactionId("txn-1").setTransactionActorPath(actorPath).
-                setMessageVersion(DataStoreVersions.CURRENT_VERSION).build();
+        ActorRef txActorRef = actorSystem.actorOf(Props.create(DoNothingActor.class));
+        String actorPath = txActorRef.path().toString();
+        CreateTransactionReply createTransactionReply = new CreateTransactionReply(actorPath, "txn-1",
+                DataStoreVersions.CURRENT_VERSION);
+
+        doReturn(actorSystem.actorSelection(actorPath)).when(mockActorContext).actorSelection(actorPath);
 
         doReturn(Futures.successful(createTransactionReply)).when(mockActorContext).
                 executeOperationAsync(eq(actorSystem.actorSelection(shardActorRef.path())),
-                        eqCreateTransaction(memberName, READ_WRITE));
+                        eqCreateTransaction(memberName, READ_WRITE), any(Timeout.class));
 
-        doReturn(true).when(mockActorContext).isPathLocal(actorPath);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_WRITE);
+        long start = System.nanoTime();
+
+        operation.run(transactionProxy);
+
+        long end = System.nanoTime();
+
+        long expected = TimeUnit.MILLISECONDS.toNanos(mockActorContext.getDatastoreContext().getOperationTimeoutInMillis());
+        Assert.assertTrue(String.format("Expected elapsed time: %s. Actual: %s",
+                expected, (end-start)), (end - start) <= expected);
+    }
+
+    private void completeOperationLocal(TransactionProxyOperation operation, DataTree dataTree){
+        ActorSystem actorSystem = getSystem();
+        ActorRef shardActorRef = actorSystem.actorOf(Props.create(DoNothingActor.class));
+
+        doReturn(actorSystem.actorSelection(shardActorRef.path())).
+                when(mockActorContext).actorSelection(shardActorRef.path().toString());
+
+        doReturn(Futures.successful(newPrimaryShardInfo(shardActorRef, dataTree))).
+                when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
 
         long start = System.nanoTime();
 
@@ -898,25 +902,48 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
         long end = System.nanoTime();
 
-        long expected = TimeUnit.SECONDS.toNanos(mockActorContext.getDatastoreContext().getOperationTimeoutInSeconds());
+        long expected = TimeUnit.MILLISECONDS.toNanos(mockActorContext.getDatastoreContext().getOperationTimeoutInMillis());
         Assert.assertTrue(String.format("Expected elapsed time: %s. Actual: %s",
                 expected, (end-start)), (end - start) <= expected);
     }
 
-    public void testWriteThrottling(boolean shardFound){
+    private static DataTree createDataTree(){
+        DataTree dataTree = mock(DataTree.class);
+        DataTreeSnapshot dataTreeSnapshot = mock(DataTreeSnapshot.class);
+        DataTreeModification dataTreeModification = mock(DataTreeModification.class);
 
-        throttleOperation(new TransactionProxyOperation() {
+        doReturn(dataTreeSnapshot).when(dataTree).takeSnapshot();
+        doReturn(dataTreeModification).when(dataTreeSnapshot).newModification();
+
+        return dataTree;
+    }
+
+    private static DataTree createDataTree(NormalizedNode<?, ?> readResponse){
+        DataTree dataTree = mock(DataTree.class);
+        DataTreeSnapshot dataTreeSnapshot = mock(DataTreeSnapshot.class);
+        DataTreeModification dataTreeModification = mock(DataTreeModification.class);
+
+        doReturn(dataTreeSnapshot).when(dataTree).takeSnapshot();
+        doReturn(dataTreeModification).when(dataTreeSnapshot).newModification();
+        doReturn(Optional.of(readResponse)).when(dataTreeModification).readNode(any(YangInstanceIdentifier.class));
+
+        return dataTree;
+    }
+
+
+    @Test
+    public void testWriteCompletionForLocalShard(){
+        completeOperationLocal(new TransactionProxyOperation() {
             @Override
             public void run(TransactionProxy transactionProxy) {
                 NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
-                expectBatchedModifications(2);
-
                 transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
 
                 transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+
             }
-        }, 1, shardFound);
+        }, createDataTree());
     }
 
     @Test
@@ -972,7 +999,6 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
     @Test
     public void testMergeThrottlingWhenShardFound(){
-
         throttleOperation(new TransactionProxyOperation() {
             @Override
             public void run(TransactionProxy transactionProxy) {
@@ -989,7 +1015,6 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
     @Test
     public void testMergeThrottlingWhenShardNotFound(){
-
         completeOperation(new TransactionProxyOperation() {
             @Override
             public void run(TransactionProxy transactionProxy) {
@@ -1021,6 +1046,22 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
     }
 
+    @Test
+    public void testMergeCompletionForLocalShard(){
+        completeOperationLocal(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+                transactionProxy.merge(TestModel.TEST_PATH, nodeToWrite);
+
+                transactionProxy.merge(TestModel.TEST_PATH, nodeToWrite);
+
+            }
+        }, createDataTree());
+    }
+
+
     @Test
     public void testDeleteThrottlingWhenShardFound(){
 
@@ -1052,6 +1093,20 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
         }, false);
     }
 
+    @Test
+    public void testDeleteCompletionForLocalShard(){
+        completeOperationLocal(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+
+                transactionProxy.delete(TestModel.TEST_PATH);
+
+                transactionProxy.delete(TestModel.TEST_PATH);
+            }
+        }, createDataTree());
+
+    }
+
     @Test
     public void testDeleteCompletion(){
         completeOperation(new TransactionProxyOperation() {
@@ -1108,7 +1163,7 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
                 NormalizedNode<?, ?> nodeToRead = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
                 doReturn(readDataReply(nodeToRead)).when(mockActorContext).executeOperationAsync(
-                        any(ActorSelection.class), eqReadData());
+                        any(ActorSelection.class), eqReadData(), any(Timeout.class));
 
                 transactionProxy.read(TestModel.TEST_PATH);
 
@@ -1118,6 +1173,33 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
     }
 
+    @Test
+    public void testReadCompletionForLocalShard(){
+        final NormalizedNode<?, ?> nodeToRead = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+        completeOperationLocal(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                transactionProxy.read(TestModel.TEST_PATH);
+
+                transactionProxy.read(TestModel.TEST_PATH);
+            }
+        }, createDataTree(nodeToRead));
+
+    }
+
+    @Test
+    public void testReadCompletionForLocalShardWhenExceptionOccurs(){
+        completeOperationLocal(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                transactionProxy.read(TestModel.TEST_PATH);
+
+                transactionProxy.read(TestModel.TEST_PATH);
+            }
+        }, createDataTree());
+
+    }
+
     @Test
     public void testExistsThrottlingWhenShardFound(){
 
@@ -1157,7 +1239,7 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
             @Override
             public void run(TransactionProxy transactionProxy) {
                 doReturn(dataExistsReply(true)).when(mockActorContext).executeOperationAsync(
-                        any(ActorSelection.class), eqDataExists());
+                        any(ActorSelection.class), eqDataExists(), any(Timeout.class));
 
                 transactionProxy.exists(TestModel.TEST_PATH);
 
@@ -1167,6 +1249,32 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
     }
 
+    @Test
+    public void testExistsCompletionForLocalShard(){
+        final NormalizedNode<?, ?> nodeToRead = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+        completeOperationLocal(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                transactionProxy.exists(TestModel.TEST_PATH);
+
+                transactionProxy.exists(TestModel.TEST_PATH);
+            }
+        }, createDataTree(nodeToRead));
+
+    }
+
+    @Test
+    public void testExistsCompletionForLocalShardWhenExceptionOccurs(){
+        completeOperationLocal(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                transactionProxy.exists(TestModel.TEST_PATH);
+
+                transactionProxy.exists(TestModel.TEST_PATH);
+            }
+        }, createDataTree());
+
+    }
     @Test
     public void testReadyThrottling(){
 
@@ -1177,9 +1285,6 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
                 expectBatchedModifications(1);
 
-                doReturn(incompleteFuture()).when(mockActorContext).executeOperationAsync(
-                        any(ActorSelection.class), any(ReadyTransaction.class));
-
                 transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
 
                 transactionProxy.ready();
@@ -1189,7 +1294,6 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
     @Test
     public void testReadyThrottlingWithTwoTransactionContexts(){
-
         throttleOperation(new TransactionProxyOperation() {
             @Override
             public void run(TransactionProxy transactionProxy) {
@@ -1198,30 +1302,25 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
                 expectBatchedModifications(2);
 
-                doReturn(incompleteFuture()).when(mockActorContext).executeOperationAsync(
-                        any(ActorSelection.class), any(ReadyTransaction.class));
-
                 transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
 
-                transactionProxy.write(TestModel.TEST_PATH, carsNode);
+                // Trying to write to Cars will cause another transaction context to get created
+                transactionProxy.write(CarsModel.BASE_PATH, carsNode);
 
+                // Now ready should block for both transaction contexts
                 transactionProxy.ready();
             }
-        }, 2, true);
+        }, 1, true, TimeUnit.MILLISECONDS.toNanos(mockActorContext.getDatastoreContext().getOperationTimeoutInMillis()) * 2);
     }
 
-    @Test
-    public void testModificationOperationBatching() throws Throwable {
+    private void testModificationOperationBatching(TransactionType type) throws Exception {
         int shardBatchedModificationCount = 3;
-        doReturn(dataStoreContextBuilder.shardBatchedModificationCount(shardBatchedModificationCount).build()).
-                when(mockActorContext).getDatastoreContext();
+        dataStoreContextBuilder.shardBatchedModificationCount(shardBatchedModificationCount);
 
-        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), type);
 
         expectBatchedModifications(actorRef, shardBatchedModificationCount);
 
-        expectReadyTransaction(actorRef);
-
         YangInstanceIdentifier writePath1 = TestModel.TEST_PATH;
         NormalizedNode<?, ?> writeNode1 = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
@@ -1243,7 +1342,7 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
         YangInstanceIdentifier deletePath1 = TestModel.TEST_PATH;
         YangInstanceIdentifier deletePath2 = TestModel.OUTER_LIST_PATH;
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_WRITE);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, type);
 
         transactionProxy.write(writePath1, writeNode1);
         transactionProxy.write(writePath2, writeNode2);
@@ -1260,24 +1359,39 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
         List<BatchedModifications> batchedModifications = captureBatchedModifications(actorRef);
         assertEquals("Captured BatchedModifications count", 3, batchedModifications.size());
 
-        verifyBatchedModifications(batchedModifications.get(0), new WriteModification(writePath1, writeNode1),
+        verifyBatchedModifications(batchedModifications.get(0), false, new WriteModification(writePath1, writeNode1),
                 new WriteModification(writePath2, writeNode2), new DeleteModification(deletePath1));
 
-        verifyBatchedModifications(batchedModifications.get(1), new MergeModification(mergePath1, mergeNode1),
+        verifyBatchedModifications(batchedModifications.get(1), false, new MergeModification(mergePath1, mergeNode1),
                 new MergeModification(mergePath2, mergeNode2), new WriteModification(writePath3, writeNode3));
 
-        verifyBatchedModifications(batchedModifications.get(2), new MergeModification(mergePath3, mergeNode3),
-                new DeleteModification(deletePath2));
+        verifyBatchedModifications(batchedModifications.get(2), true, true,
+                new MergeModification(mergePath3, mergeNode3), new DeleteModification(deletePath2));
+
+        assertEquals("getTotalMessageCount", 3, batchedModifications.get(2).getTotalMessagesSent());
+    }
+
+    @Test
+    public void testReadWriteModificationOperationBatching() throws Throwable {
+        testModificationOperationBatching(READ_WRITE);
+    }
+
+    @Test
+    public void testWriteOnlyModificationOperationBatching() throws Throwable {
+        testModificationOperationBatching(WRITE_ONLY);
+    }
 
-        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
-                BatchedModificationsReply.class, BatchedModificationsReply.class, BatchedModificationsReply.class);
+    @Test
+    public void testOptimizedWriteOnlyModificationOperationBatching() throws Throwable {
+        dataStoreContextBuilder.writeOnlyTransactionOptimizationsEnabled(true);
+        testModificationOperationBatching(WRITE_ONLY);
     }
 
     @Test
     public void testModificationOperationBatchingWithInterleavedReads() throws Throwable {
+
         int shardBatchedModificationCount = 10;
-        doReturn(dataStoreContextBuilder.shardBatchedModificationCount(shardBatchedModificationCount).build()).
-                when(mockActorContext).getDatastoreContext();
+        dataStoreContextBuilder.shardBatchedModificationCount(shardBatchedModificationCount);
 
         ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
 
@@ -1297,16 +1411,16 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
         YangInstanceIdentifier deletePath = TestModel.OUTER_LIST_PATH;
 
-        doReturn(readSerializedDataReply(writeNode2)).when(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedReadData(writePath2));
+        doReturn(readDataReply(writeNode2)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqReadData(writePath2), any(Timeout.class));
 
-        doReturn(readSerializedDataReply(mergeNode2)).when(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedReadData(mergePath2));
+        doReturn(readDataReply(mergeNode2)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqReadData(mergePath2), any(Timeout.class));
 
-        doReturn(dataExistsSerializedReply(true)).when(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedDataExists());
+        doReturn(dataExistsReply(true)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqDataExists(), any(Timeout.class));
 
-        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_WRITE);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
 
         transactionProxy.write(writePath1, writeNode1);
         transactionProxy.write(writePath2, writeNode2);
@@ -1333,34 +1447,103 @@ public class TransactionProxyTest extends AbstractTransactionProxyTest {
         List<BatchedModifications> batchedModifications = captureBatchedModifications(actorRef);
         assertEquals("Captured BatchedModifications count", 3, batchedModifications.size());
 
-        verifyBatchedModifications(batchedModifications.get(0), new WriteModification(writePath1, writeNode1),
+        verifyBatchedModifications(batchedModifications.get(0), false, new WriteModification(writePath1, writeNode1),
                 new WriteModification(writePath2, writeNode2));
 
-        verifyBatchedModifications(batchedModifications.get(1), new MergeModification(mergePath1, mergeNode1),
+        verifyBatchedModifications(batchedModifications.get(1), false, new MergeModification(mergePath1, mergeNode1),
                 new MergeModification(mergePath2, mergeNode2));
 
-        verifyBatchedModifications(batchedModifications.get(2), new DeleteModification(deletePath));
+        verifyBatchedModifications(batchedModifications.get(2), false, new DeleteModification(deletePath));
 
         InOrder inOrder = Mockito.inOrder(mockActorContext);
         inOrder.verify(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), isA(BatchedModifications.class));
+                eq(actorSelection(actorRef)), isA(BatchedModifications.class), any(Timeout.class));
 
         inOrder.verify(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedReadData(writePath2));
+                eq(actorSelection(actorRef)), eqReadData(writePath2), any(Timeout.class));
 
         inOrder.verify(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), isA(BatchedModifications.class));
+                eq(actorSelection(actorRef)), isA(BatchedModifications.class), any(Timeout.class));
 
         inOrder.verify(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedReadData(mergePath2));
+                eq(actorSelection(actorRef)), eqReadData(mergePath2), any(Timeout.class));
 
         inOrder.verify(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), isA(BatchedModifications.class));
+                eq(actorSelection(actorRef)), isA(BatchedModifications.class), any(Timeout.class));
 
         inOrder.verify(mockActorContext).executeOperationAsync(
-                eq(actorSelection(actorRef)), eqSerializedDataExists());
+                eq(actorSelection(actorRef)), eqDataExists(), any(Timeout.class));
+    }
+
+    @Test
+    public void testReadRoot() throws ReadFailedException, InterruptedException, ExecutionException, java.util.concurrent.TimeoutException {
+
+        SchemaContext schemaContext = SchemaContextHelper.full();
+        Configuration configuration = mock(Configuration.class);
+        doReturn(configuration).when(mockActorContext).getConfiguration();
+        doReturn(schemaContext).when(mockActorContext).getSchemaContext();
+        doReturn(Sets.newHashSet("test", "cars")).when(configuration).getAllShardNames();
+
+        NormalizedNode<?, ?> expectedNode1 = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+        NormalizedNode<?, ?> expectedNode2 = ImmutableNodes.containerNode(CarsModel.CARS_QNAME);
+
+        setUpReadData("test", NormalizedNodeAggregatorTest.getRootNode(expectedNode1, schemaContext));
+        setUpReadData("cars", NormalizedNodeAggregatorTest.getRootNode(expectedNode2, schemaContext));
+
+        doReturn(MemberName.forName(memberName)).when(mockActorContext).getCurrentMemberName();
+
+        doReturn(getSystem().dispatchers().defaultGlobalDispatcher()).when(mockActorContext).getClientDispatcher();
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
+
+        Optional<NormalizedNode<?, ?>> readOptional = transactionProxy.read(
+                YangInstanceIdentifier.EMPTY).get(5, TimeUnit.SECONDS);
 
-        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
-                BatchedModificationsReply.class, BatchedModificationsReply.class, BatchedModificationsReply.class);
+        assertEquals("NormalizedNode isPresent", true, readOptional.isPresent());
+
+        NormalizedNode<?, ?> normalizedNode = readOptional.get();
+
+        assertTrue("Expect value to be a Collection", normalizedNode.getValue() instanceof Collection);
+
+        @SuppressWarnings("unchecked")
+        Collection<NormalizedNode<?,?>> collection = (Collection<NormalizedNode<?,?>>) normalizedNode.getValue();
+
+        for(NormalizedNode<?,?> node : collection){
+            assertTrue("Expected " + node + " to be a ContainerNode", node instanceof ContainerNode);
+        }
+
+        assertTrue("Child with QName = " + TestModel.TEST_QNAME + " not found",
+                NormalizedNodeAggregatorTest.findChildWithQName(collection, TestModel.TEST_QNAME) != null);
+
+        assertEquals(expectedNode1, NormalizedNodeAggregatorTest.findChildWithQName(collection, TestModel.TEST_QNAME));
+
+        assertTrue("Child with QName = " + CarsModel.BASE_QNAME + " not found",
+                NormalizedNodeAggregatorTest.findChildWithQName(collection, CarsModel.BASE_QNAME) != null);
+
+        assertEquals(expectedNode2, NormalizedNodeAggregatorTest.findChildWithQName(collection, CarsModel.BASE_QNAME));
+    }
+
+
+    private void setUpReadData(String shardName, NormalizedNode<?, ?> expectedNode) {
+        ActorSystem actorSystem = getSystem();
+        ActorRef shardActorRef = getSystem().actorOf(Props.create(DoNothingActor.class));
+
+        doReturn(getSystem().actorSelection(shardActorRef.path())).
+                when(mockActorContext).actorSelection(shardActorRef.path().toString());
+
+        doReturn(primaryShardInfoReply(getSystem(), shardActorRef)).
+                when(mockActorContext).findPrimaryShardAsync(eq(shardName));
+
+        ActorRef txActorRef = actorSystem.actorOf(Props.create(DoNothingActor.class));
+
+        doReturn(actorSystem.actorSelection(txActorRef.path())).
+                when(mockActorContext).actorSelection(txActorRef.path().toString());
+
+        doReturn(Futures.successful(createTransactionReply(txActorRef, DataStoreVersions.CURRENT_VERSION))).when(mockActorContext).
+                executeOperationAsync(eq(actorSystem.actorSelection(shardActorRef.path())),
+                        eqCreateTransaction(memberName, TransactionType.READ_ONLY), any(Timeout.class));
+
+        doReturn(readDataReply(expectedNode)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(txActorRef)), eqReadData(YangInstanceIdentifier.EMPTY), any(Timeout.class));
     }
 }