Refactor MessageCollectorActor and DoNothingActor
[controller.git] / opendaylight / md-sal / sal-distributed-datastore / src / test / java / org / opendaylight / controller / cluster / datastore / TransactionProxyTest.java
index 4f3a194b0db068d4dfd8cabffab40087edb8adfe..a5625637f4b5720d2d8084dcd415ab94b31a0c7a 100644 (file)
+/*
+ * 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.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.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+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.util.concurrent.ListenableFuture;
-import junit.framework.Assert;
+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.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.CloseTransaction;
-import org.opendaylight.controller.cluster.datastore.messages.DeleteData;
-import org.opendaylight.controller.cluster.datastore.messages.MergeData;
-import org.opendaylight.controller.cluster.datastore.messages.ReadDataReply;
-import org.opendaylight.controller.cluster.datastore.messages.ReadyTransactionReply;
-import org.opendaylight.controller.cluster.datastore.messages.WriteData;
-import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
-import org.opendaylight.controller.cluster.datastore.utils.DoNothingActor;
-import org.opendaylight.controller.cluster.datastore.utils.MessageCollectorActor;
-import org.opendaylight.controller.cluster.datastore.utils.MockActorContext;
+import org.opendaylight.controller.cluster.datastore.messages.CommitTransactionReply;
+import org.opendaylight.controller.cluster.datastore.messages.PrimaryShardInfo;
+import org.opendaylight.controller.cluster.datastore.messages.ReadyTransaction;
+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.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 org.opendaylight.yangtools.yang.model.api.SchemaContext;
+import scala.concurrent.Promise;
 
-import java.util.List;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
+@SuppressWarnings("resource")
+public class TransactionProxyTest extends AbstractTransactionProxyTest {
 
-public class TransactionProxyTest extends AbstractActorTest {
+    @SuppressWarnings("serial")
+    static class TestException extends RuntimeException {
+    }
 
-    private ExecutorService transactionExecutor =
-        Executors.newSingleThreadExecutor();
+    static interface Invoker {
+        CheckedFuture<?, ReadFailedException> invoke(TransactionProxy proxy) throws Exception;
+    }
 
     @Test
     public void testRead() throws Exception {
-        final Props props = Props.create(DoNothingActor.class);
-        final ActorRef actorRef = getSystem().actorOf(props);
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
+
+        doReturn(readSerializedDataReply(null)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedReadData());
+
+        Optional<NormalizedNode<?, ?>> readOptional = transactionProxy.read(
+                TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);
+
+        assertEquals("NormalizedNode isPresent", false, readOptional.isPresent());
+
+        NormalizedNode<?, ?> expectedNode = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+        doReturn(readSerializedDataReply(expectedNode)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedReadData());
+
+        readOptional = transactionProxy.read(TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);
+
+        assertEquals("NormalizedNode isPresent", true, readOptional.isPresent());
+
+        assertEquals("Response NormalizedNode", expectedNode, readOptional.get());
+    }
+
+    @Test(expected = ReadFailedException.class)
+    public void testReadWithInvalidReplyMessageType() throws Exception {
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
+
+        doReturn(Futures.successful(new Object())).when(mockActorContext).
+                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedReadData());
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
+
+        transactionProxy.read(TestModel.TEST_PATH).checkedGet(5, TimeUnit.SECONDS);
+    }
+
+    @Test(expected = TestException.class)
+    public void testReadWithAsyncRemoteOperatonFailure() throws Throwable {
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
+
+        doReturn(Futures.failed(new TestException())).when(mockActorContext).
+                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedReadData());
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
+
+        propagateReadFailedExceptionCause(transactionProxy.read(TestModel.TEST_PATH));
+    }
+
+    private void testExceptionOnInitialCreateTransaction(Exception exToThrow, Invoker invoker)
+            throws Throwable {
+        ActorRef actorRef = getSystem().actorOf(Props.create(DoNothingActor.class));
+
+        if (exToThrow instanceof PrimaryNotFoundException) {
+            doReturn(Futures.failed(exToThrow)).when(mockActorContext).findPrimaryShardAsync(anyString());
+        } else {
+            doReturn(primaryShardInfoReply(getSystem(), actorRef)).
+                    when(mockActorContext).findPrimaryShardAsync(anyString());
+        }
+
+        doReturn(Futures.failed(exToThrow)).when(mockActorContext).executeOperationAsync(
+                any(ActorSelection.class), any(), any(Timeout.class));
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
+
+        propagateReadFailedExceptionCause(invoker.invoke(transactionProxy));
+    }
+
+    private void testReadWithExceptionOnInitialCreateTransaction(Exception exToThrow) throws Throwable {
+        testExceptionOnInitialCreateTransaction(exToThrow, new Invoker() {
+            @Override
+            public CheckedFuture<?, ReadFailedException> invoke(TransactionProxy proxy) throws Exception {
+                return proxy.read(TestModel.TEST_PATH);
+            }
+        });
+    }
+
+    @Test(expected = PrimaryNotFoundException.class)
+    public void testReadWhenAPrimaryNotFoundExceptionIsThrown() throws Throwable {
+        testReadWithExceptionOnInitialCreateTransaction(new PrimaryNotFoundException("test"));
+    }
+
+    @Test(expected = TimeoutException.class)
+    public void testReadWhenATimeoutExceptionIsThrown() throws Throwable {
+        testReadWithExceptionOnInitialCreateTransaction(new TimeoutException("test",
+                new Exception("reason")));
+    }
+
+    @Test(expected = TestException.class)
+    public void testReadWhenAnyOtherExceptionIsThrown() throws Throwable {
+        testReadWithExceptionOnInitialCreateTransaction(new TestException());
+    }
+
+    @Test
+    public void testReadWithPriorRecordingOperationSuccessful() throws Throwable {
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
+
+        NormalizedNode<?, ?> expectedNode = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+        expectBatchedModifications(actorRef, 1);
+
+        doReturn(readSerializedDataReply(expectedNode)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedReadData());
 
-        final MockActorContext actorContext = new MockActorContext(this.getSystem());
-        actorContext.setExecuteShardOperationResponse(createTransactionReply(actorRef));
-        actorContext.setExecuteRemoteOperationResponse("message");
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
 
-        TransactionProxy transactionProxy =
-            new TransactionProxy(actorContext,
-                TransactionProxy.TransactionType.READ_ONLY, transactionExecutor, TestModel.createTestContext());
+        transactionProxy.write(TestModel.TEST_PATH, expectedNode);
 
+        Optional<NormalizedNode<?, ?>> readOptional = transactionProxy.read(
+                TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);
+
+        assertEquals("NormalizedNode isPresent", true, readOptional.isPresent());
+        assertEquals("Response NormalizedNode", expectedNode, readOptional.get());
+
+        InOrder inOrder = Mockito.inOrder(mockActorContext);
+        inOrder.verify(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), isA(BatchedModifications.class));
+
+        inOrder.verify(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedReadData());
+    }
 
-        ListenableFuture<Optional<NormalizedNode<?, ?>>> read =
-            transactionProxy.read(TestModel.TEST_PATH);
+    @Test(expected=IllegalStateException.class)
+    public void testReadPreConditionCheck() {
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
+        transactionProxy.read(TestModel.TEST_PATH);
+    }
 
-        Optional<NormalizedNode<?, ?>> normalizedNodeOptional = read.get();
+    @Test(expected=IllegalArgumentException.class)
+    public void testInvalidCreateTransactionReply() throws Throwable {
+        ActorRef actorRef = getSystem().actorOf(Props.create(DoNothingActor.class));
 
-        Assert.assertFalse(normalizedNodeOptional.isPresent());
+        doReturn(getSystem().actorSelection(actorRef.path())).when(mockActorContext).
+            actorSelection(actorRef.path().toString());
 
-        actorContext.setExecuteRemoteOperationResponse(new ReadDataReply(
-            ImmutableNodes.containerNode(TestModel.TEST_QNAME)));
+        doReturn(primaryShardInfoReply(getSystem(), actorRef)).
+            when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
 
-        read = transactionProxy.read(TestModel.TEST_PATH);
+        doReturn(Futures.successful(new Object())).when(mockActorContext).executeOperationAsync(
+            eq(getSystem().actorSelection(actorRef.path())), eqCreateTransaction(memberName, READ_ONLY),
+            any(Timeout.class));
 
-        normalizedNodeOptional = read.get();
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
 
-        Assert.assertTrue(normalizedNodeOptional.isPresent());
+        propagateReadFailedExceptionCause(transactionProxy.read(TestModel.TEST_PATH));
     }
 
     @Test
-    public void testReadWhenANullIsReturned() throws Exception {
-        final Props props = Props.create(DoNothingActor.class);
-        final ActorRef actorRef = getSystem().actorOf(props);
+    public void testExists() throws Exception {
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
+
+        doReturn(dataExistsSerializedReply(false)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedDataExists());
+
+        Boolean exists = transactionProxy.exists(TestModel.TEST_PATH).checkedGet();
 
-        final MockActorContext actorContext = new MockActorContext(this.getSystem());
-        actorContext.setExecuteShardOperationResponse(createTransactionReply(actorRef));
-        actorContext.setExecuteRemoteOperationResponse("message");
+        assertEquals("Exists response", false, exists);
+
+        doReturn(dataExistsSerializedReply(true)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedDataExists());
+
+        exists = transactionProxy.exists(TestModel.TEST_PATH).checkedGet();
+
+        assertEquals("Exists response", true, exists);
+    }
 
-        TransactionProxy transactionProxy =
-            new TransactionProxy(actorContext,
-                TransactionProxy.TransactionType.READ_ONLY, transactionExecutor, TestModel.createTestContext());
+    @Test(expected = PrimaryNotFoundException.class)
+    public void testExistsWhenAPrimaryNotFoundExceptionIsThrown() throws Throwable {
+        testExceptionOnInitialCreateTransaction(new PrimaryNotFoundException("test"), new Invoker() {
+            @Override
+            public CheckedFuture<?, ReadFailedException> invoke(TransactionProxy proxy) throws Exception {
+                return proxy.exists(TestModel.TEST_PATH);
+            }
+        });
+    }
 
+    @Test(expected = ReadFailedException.class)
+    public void testExistsWithInvalidReplyMessageType() throws Exception {
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
 
-        ListenableFuture<Optional<NormalizedNode<?, ?>>> read =
-            transactionProxy.read(TestModel.TEST_PATH);
+        doReturn(Futures.successful(new Object())).when(mockActorContext).
+                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedDataExists());
 
-        Optional<NormalizedNode<?, ?>> normalizedNodeOptional = read.get();
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
 
-        Assert.assertFalse(normalizedNodeOptional.isPresent());
+        transactionProxy.exists(TestModel.TEST_PATH).checkedGet(5, TimeUnit.SECONDS);
+    }
 
-        actorContext.setExecuteRemoteOperationResponse(new ReadDataReply(
-            null));
+    @Test(expected = TestException.class)
+    public void testExistsWithAsyncRemoteOperatonFailure() throws Throwable {
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
 
-        read = transactionProxy.read(TestModel.TEST_PATH);
+        doReturn(Futures.failed(new TestException())).when(mockActorContext).
+                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedDataExists());
 
-        normalizedNodeOptional = read.get();
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
 
-        Assert.assertFalse(normalizedNodeOptional.isPresent());
+        propagateReadFailedExceptionCause(transactionProxy.exists(TestModel.TEST_PATH));
     }
 
     @Test
-    public void testWrite() throws Exception {
-        final Props props = Props.create(MessageCollectorActor.class);
-        final ActorRef actorRef = getSystem().actorOf(props);
+    public void testExistsWithPriorRecordingOperationSuccessful() throws Throwable {
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
+
+        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
-        final MockActorContext actorContext = new MockActorContext(this.getSystem());
-        actorContext.setExecuteShardOperationResponse(createTransactionReply(actorRef));
-        actorContext.setExecuteRemoteOperationResponse("message");
+        expectBatchedModifications(actorRef, 1);
 
-        TransactionProxy transactionProxy =
-            new TransactionProxy(actorContext,
-                TransactionProxy.TransactionType.READ_ONLY, transactionExecutor, TestModel.createTestContext());
+        doReturn(dataExistsSerializedReply(true)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedDataExists());
 
-        transactionProxy.write(TestModel.TEST_PATH,
-            ImmutableNodes.containerNode(TestModel.NAME_QNAME));
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
 
-        ActorContext testContext = new ActorContext(getSystem(), getSystem().actorOf(Props.create(DoNothingActor.class)));
-        Object messages = testContext
-            .executeLocalOperation(actorRef, "messages",
-                ActorContext.ASK_DURATION);
+        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
 
-        Assert.assertNotNull(messages);
+        Boolean exists = transactionProxy.exists(TestModel.TEST_PATH).checkedGet();
 
-        Assert.assertTrue(messages instanceof List);
+        assertEquals("Exists response", true, exists);
 
-        List<Object> listMessages = (List<Object>) messages;
+        InOrder inOrder = Mockito.inOrder(mockActorContext);
+        inOrder.verify(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), isA(BatchedModifications.class));
 
-        Assert.assertEquals(1, listMessages.size());
+        inOrder.verify(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedDataExists());
+    }
 
-        Assert.assertTrue(listMessages.get(0) instanceof WriteData);
+    @Test(expected=IllegalStateException.class)
+    public void testExistsPreConditionCheck() {
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
+        transactionProxy.exists(TestModel.TEST_PATH);
     }
 
     @Test
-    public void testMerge() throws Exception {
-        final Props props = Props.create(MessageCollectorActor.class);
-        final ActorRef actorRef = getSystem().actorOf(props);
+    public void testWrite() throws Exception {
+        dataStoreContextBuilder.shardBatchedModificationCount(1);
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
+
+        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
-        final MockActorContext actorContext = new MockActorContext(this.getSystem());
-        actorContext.setExecuteShardOperationResponse(createTransactionReply(actorRef));
-        actorContext.setExecuteRemoteOperationResponse("message");
+        expectBatchedModifications(actorRef, 1);
 
-        TransactionProxy transactionProxy =
-            new TransactionProxy(actorContext,
-                TransactionProxy.TransactionType.READ_ONLY, transactionExecutor, TestModel.createTestContext());
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
-        transactionProxy.merge(TestModel.TEST_PATH,
-            ImmutableNodes.containerNode(TestModel.NAME_QNAME));
+        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
 
-        ActorContext testContext = new ActorContext(getSystem(), getSystem().actorOf(Props.create(DoNothingActor.class)));
-        Object messages = testContext
-            .executeLocalOperation(actorRef, "messages",
-                ActorContext.ASK_DURATION);
+        verifyOneBatchedModification(actorRef, new WriteModification(TestModel.TEST_PATH, nodeToWrite), false);
+    }
+
+    @Test
+    public void testWriteAfterAsyncRead() throws Throwable {
+        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), any(Timeout.class));
+
+        doReturn(readSerializedDataReply(null)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedReadData());
+
+        expectBatchedModificationsReady(actorRef);
+
+        final NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+        final TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
+
+        final CountDownLatch readComplete = new CountDownLatch(1);
+        final AtomicReference<Throwable> caughtEx = new AtomicReference<>();
+        com.google.common.util.concurrent.Futures.addCallback(transactionProxy.read(TestModel.TEST_PATH),
+                new  FutureCallback<Optional<NormalizedNode<?, ?>>>() {
+                    @Override
+                    public void onSuccess(Optional<NormalizedNode<?, ?>> result) {
+                        try {
+                            transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+                        } catch (Exception e) {
+                            caughtEx.set(e);
+                        } finally {
+                            readComplete.countDown();
+                        }
+                    }
+
+                    @Override
+                    public void onFailure(Throwable t) {
+                        caughtEx.set(t);
+                        readComplete.countDown();
+                    }
+                });
+
+        createTxPromise.success(createTransactionReply(actorRef, DataStoreVersions.CURRENT_VERSION));
+
+        Uninterruptibles.awaitUninterruptibly(readComplete, 5, TimeUnit.SECONDS);
+
+        if(caughtEx.get() != null) {
+            throw caughtEx.get();
+        }
+
+        // This sends the batched modification.
+        transactionProxy.ready();
+
+        verifyOneBatchedModification(actorRef, new WriteModification(TestModel.TEST_PATH, nodeToWrite), true);
+    }
 
-        Assert.assertNotNull(messages);
+    @Test(expected=IllegalStateException.class)
+    public void testWritePreConditionCheck() {
+        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(mockComponentFactory, WRITE_ONLY);
+
+        transactionProxy.ready();
+
+        transactionProxy.write(TestModel.TEST_PATH, ImmutableNodes.containerNode(TestModel.TEST_QNAME));
+    }
+
+    @Test
+    public void testMerge() throws Exception {
+        dataStoreContextBuilder.shardBatchedModificationCount(1);
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
 
-        Assert.assertTrue(messages instanceof List);
+        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
 
-        List<Object> listMessages = (List<Object>) messages;
+        expectBatchedModifications(actorRef, 1);
 
-        Assert.assertEquals(1, listMessages.size());
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
-        Assert.assertTrue(listMessages.get(0) instanceof MergeData);
+        transactionProxy.merge(TestModel.TEST_PATH, nodeToWrite);
+
+        verifyOneBatchedModification(actorRef, new MergeModification(TestModel.TEST_PATH, nodeToWrite), false);
     }
 
     @Test
     public void testDelete() throws Exception {
-        final Props props = Props.create(MessageCollectorActor.class);
-        final ActorRef actorRef = getSystem().actorOf(props);
+        dataStoreContextBuilder.shardBatchedModificationCount(1);
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
 
-        final MockActorContext actorContext = new MockActorContext(this.getSystem());
-        actorContext.setExecuteShardOperationResponse(createTransactionReply(actorRef));
-        actorContext.setExecuteRemoteOperationResponse("message");
+        expectBatchedModifications(actorRef, 1);
 
-        TransactionProxy transactionProxy =
-            new TransactionProxy(actorContext,
-                TransactionProxy.TransactionType.READ_ONLY, transactionExecutor, TestModel.createTestContext());
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
         transactionProxy.delete(TestModel.TEST_PATH);
 
-        ActorContext testContext = new ActorContext(getSystem(), getSystem().actorOf(Props.create(DoNothingActor.class)));
-        Object messages = testContext
-            .executeLocalOperation(actorRef, "messages",
-                ActorContext.ASK_DURATION);
+        verifyOneBatchedModification(actorRef, new DeleteModification(TestModel.TEST_PATH), false);
+    }
+
+    @Test
+    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());
+
+        expectBatchedModifications(actorRef, 1);
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
+
+        transactionProxy.read(TestModel.TEST_PATH);
+
+        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+
+        transactionProxy.read(TestModel.TEST_PATH);
+
+        transactionProxy.read(TestModel.TEST_PATH);
+
+        List<BatchedModifications> batchedModifications = captureBatchedModifications(actorRef);
+        assertEquals("Captured BatchedModifications count", 1, batchedModifications.size());
+
+        verifyBatchedModifications(batchedModifications.get(0), false,
+                new WriteModification(TestModel.TEST_PATH, nodeToWrite));
+    }
+
+    @Test
+    public void testReadyWithReadWrite() 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());
+
+        expectBatchedModificationsReady(actorRef, true);
+
+        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 SingleCommitCohortProxy);
+
+        verifyCohortFutures((SingleCommitCohortProxy)ready, new CommitTransactionReply().toSerializable());
+
+        List<BatchedModifications> batchedModifications = captureBatchedModifications(actorRef);
+        assertEquals("Captured BatchedModifications count", 1, batchedModifications.size());
+
+        verifyBatchedModifications(batchedModifications.get(0), true, true,
+                new WriteModification(TestModel.TEST_PATH, nodeToWrite));
+
+        assertEquals("getTotalMessageCount", 1, batchedModifications.get(0).getTotalMessagesSent());
+    }
+
+    @Test
+    public void testReadyWithNoModifications() throws Exception {
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
+
+        doReturn(readSerializedDataReply(null)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedReadData());
+
+        expectBatchedModificationsReady(actorRef, true);
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
+
+        transactionProxy.read(TestModel.TEST_PATH);
+
+        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
+
+        assertTrue(ready instanceof SingleCommitCohortProxy);
 
-        Assert.assertNotNull(messages);
+        verifyCohortFutures((SingleCommitCohortProxy)ready, new CommitTransactionReply().toSerializable());
 
-        Assert.assertTrue(messages instanceof List);
+        List<BatchedModifications> batchedModifications = captureBatchedModifications(actorRef);
+        assertEquals("Captured BatchedModifications count", 1, batchedModifications.size());
 
-        List<Object> listMessages = (List<Object>) messages;
+        verifyBatchedModifications(batchedModifications.get(0), true, true);
+    }
+
+    @Test
+    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));
+    }
+
+    @Test
+    public void testReadyWithWriteOnlyAndLastBatchPending() throws Exception {
+        dataStoreContextBuilder.writeOnlyTransactionOptimizationsEnabled(true);
+
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
+
+        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+        expectBatchedModificationsReady(actorRef, true);
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
+
+        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+
+        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
+
+        assertTrue(ready instanceof SingleCommitCohortProxy);
+
+        verifyCohortFutures((SingleCommitCohortProxy)ready, new CommitTransactionReply().toSerializable());
+
+        List<BatchedModifications> batchedModifications = captureBatchedModifications(actorRef);
+        assertEquals("Captured BatchedModifications count", 1, batchedModifications.size());
+
+        verifyBatchedModifications(batchedModifications.get(0), true, true,
+                new WriteModification(TestModel.TEST_PATH, nodeToWrite));
+
+        verify(mockActorContext, never()).executeOperationAsync(eq(actorSelection(actorRef)),
+                isA(ReadyTransaction.SERIALIZABLE_CLASS));
+    }
+
+    @Test
+    public void testReadyWithWriteOnlyAndLastBatchEmpty() throws Exception {
+        dataStoreContextBuilder.shardBatchedModificationCount(1).writeOnlyTransactionOptimizationsEnabled(true);
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
+
+        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+        expectBatchedModificationsReady(actorRef, true);
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
-        Assert.assertEquals(1, listMessages.size());
+        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
 
-        Assert.assertEquals(DeleteData.SERIALIZABLE_CLASS, listMessages.get(0).getClass());
+        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
+
+        assertTrue(ready instanceof SingleCommitCohortProxy);
+
+        verifyCohortFutures((SingleCommitCohortProxy)ready, new CommitTransactionReply().toSerializable());
+
+        List<BatchedModifications> batchedModifications = captureBatchedModifications(actorRef);
+        assertEquals("Captured BatchedModifications count", 2, batchedModifications.size());
+
+        verifyBatchedModifications(batchedModifications.get(0), false,
+                new WriteModification(TestModel.TEST_PATH, nodeToWrite));
+
+        verifyBatchedModifications(batchedModifications.get(1), true, true);
+
+        verify(mockActorContext, never()).executeOperationAsync(eq(actorSelection(actorRef)),
+                isA(ReadyTransaction.SERIALIZABLE_CLASS));
+    }
+
+    @Test
+    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();
+
+        assertTrue(ready instanceof SingleCommitCohortProxy);
+
+        verifyCohortFutures((SingleCommitCohortProxy)ready, TestException.class);
     }
 
     @Test
-    public void testReady() throws Exception {
-        final Props props = Props.create(DoNothingActor.class);
-        final ActorRef doNothingActorRef = getSystem().actorOf(props);
+    public void testReadyWithDebugContextEnabled() throws Exception {
+        dataStoreContextBuilder.transactionDebugContextEnabled(true);
+
+        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());
+    }
 
-        final MockActorContext actorContext = new MockActorContext(this.getSystem());
-        actorContext.setExecuteShardOperationResponse(createTransactionReply(doNothingActorRef));
-        actorContext.setExecuteRemoteOperationResponse(new ReadyTransactionReply(doNothingActorRef.path()));
+    private void testWriteOnlyTxWithFindPrimaryShardFailure(Exception toThrow) throws Exception {
+        doReturn(Futures.failed(toThrow)).when(mockActorContext).findPrimaryShardAsync(anyString());
 
-        TransactionProxy transactionProxy =
-            new TransactionProxy(actorContext,
-                TransactionProxy.TransactionType.READ_ONLY, transactionExecutor, TestModel.createTestContext());
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, WRITE_ONLY);
 
+        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+        transactionProxy.merge(TestModel.TEST_PATH, nodeToWrite);
+
+        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+
+        transactionProxy.delete(TestModel.TEST_PATH);
 
         DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
 
-        Assert.assertTrue(ready instanceof ThreePhaseCommitCohortProxy);
+        assertTrue(ready instanceof SingleCommitCohortProxy);
 
-        ThreePhaseCommitCohortProxy proxy = (ThreePhaseCommitCohortProxy) ready;
+        verifyCohortFutures((SingleCommitCohortProxy)ready, toThrow.getClass());
+    }
+
+    @Test
+    public void testWriteOnlyTxWithPrimaryNotFoundException() throws Exception {
+        testWriteOnlyTxWithFindPrimaryShardFailure(new PrimaryNotFoundException("mock"));
+    }
 
-        Assert.assertTrue("No cohort paths returned", proxy.getCohortPaths().size() > 0);
+    @Test
+    public void testWriteOnlyTxWithNotInitializedException() throws Exception {
+        testWriteOnlyTxWithFindPrimaryShardFailure(new NotInitializedException("mock"));
+    }
 
+    @Test
+    public void testWriteOnlyTxWithNoShardLeaderException() throws Exception {
+        testWriteOnlyTxWithFindPrimaryShardFailure(new NoShardLeaderException("mock"));
     }
 
     @Test
-    public void testGetIdentifier(){
-        final Props props = Props.create(DoNothingActor.class);
-        final ActorRef doNothingActorRef = getSystem().actorOf(props);
+    public void testReadyWithInvalidReplyMessageType() throws Exception {
+        dataStoreContextBuilder.writeOnlyTransactionOptimizationsEnabled(true);
+        ActorRef actorRef1 = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);
+
+        ActorRef actorRef2 = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY, "junk");
 
-        final MockActorContext actorContext = new MockActorContext(this.getSystem());
-        actorContext.setExecuteShardOperationResponse( createTransactionReply(doNothingActorRef) );
+        doReturn(Futures.successful(new Object())).when(mockActorContext).
+                executeOperationAsync(eq(actorSelection(actorRef1)), isA(BatchedModifications.class));
+
+        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(actorRef2),
+                IllegalArgumentException.class);
+    }
 
-        TransactionProxy transactionProxy =
-            new TransactionProxy(actorContext,
-                TransactionProxy.TransactionType.READ_ONLY, transactionExecutor, TestModel.createTestContext());
+    @Test
+    public void testGetIdentifier() {
+        setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
 
-        Assert.assertNotNull(transactionProxy.getIdentifier());
+        Object id = transactionProxy.getIdentifier();
+        assertNotNull("getIdentifier returned null", id);
+        assertTrue("Invalid identifier: " + id, id.toString().startsWith(memberName));
     }
 
     @Test
-    public void testClose(){
-        final Props props = Props.create(MessageCollectorActor.class);
-        final ActorRef actorRef = getSystem().actorOf(props);
+    public void testClose() throws Exception{
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
+
+        doReturn(readSerializedDataReply(null)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedReadData());
 
-        final MockActorContext actorContext = new MockActorContext(this.getSystem());
-        actorContext.setExecuteShardOperationResponse(createTransactionReply(actorRef));
-        actorContext.setExecuteRemoteOperationResponse("message");
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
 
-        TransactionProxy transactionProxy =
-            new TransactionProxy(actorContext,
-                TransactionProxy.TransactionType.READ_ONLY, transactionExecutor, TestModel.createTestContext());
+        transactionProxy.read(TestModel.TEST_PATH);
 
         transactionProxy.close();
 
-        ActorContext testContext = new ActorContext(getSystem(), getSystem().actorOf(Props.create(DoNothingActor.class)));
-        Object messages = testContext
-            .executeLocalOperation(actorRef, "messages",
-                ActorContext.ASK_DURATION);
+        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 {
+        setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
+        doReturn(true).when(mockActorContext).isPathLocal(anyString());
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
+
+        // negative test case with null as the reply
+        doReturn(readDataReply(null)).when(mockActorContext).executeOperationAsync(
+            any(ActorSelection.class), eqReadData());
+
+        Optional<NormalizedNode<?, ?>> readOptional = transactionProxy.read(
+            TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);
+
+        assertEquals("NormalizedNode isPresent", false, readOptional.isPresent());
+
+        // test case with node as read data reply
+        NormalizedNode<?, ?> expectedNode = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+        doReturn(readDataReply(expectedNode)).when(mockActorContext).executeOperationAsync(
+            any(ActorSelection.class), eqReadData());
+
+        readOptional = transactionProxy.read(TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);
+
+        assertEquals("NormalizedNode isPresent", true, readOptional.isPresent());
+
+        assertEquals("Response NormalizedNode", expectedNode, readOptional.get());
+
+        // test for local data exists
+        doReturn(dataExistsReply(true)).when(mockActorContext).executeOperationAsync(
+            any(ActorSelection.class), eqDataExists());
 
-        Assert.assertNotNull(messages);
+        boolean exists = transactionProxy.exists(TestModel.TEST_PATH).checkedGet();
 
-        Assert.assertTrue(messages instanceof List);
+        assertEquals("Exists response", true, exists);
+    }
+
+    @Test
+    public void testLocalTxActorReady() throws Exception {
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
+        doReturn(true).when(mockActorContext).isPathLocal(anyString());
+
+        expectBatchedModificationsReady(actorRef, true);
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
+
+        NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+
+        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();
 
-        List<Object> listMessages = (List<Object>) messages;
+        assertTrue(ready instanceof SingleCommitCohortProxy);
+
+        verifyCohortFutures((SingleCommitCohortProxy)ready, new CommitTransactionReply().toSerializable());
+    }
+
+    private static interface TransactionProxyOperation {
+        void run(TransactionProxy transactionProxy);
+    }
+
+    private void throttleOperation(TransactionProxyOperation operation) {
+        throttleOperation(operation, 1, true);
+    }
+
+    private void throttleOperation(TransactionProxyOperation operation, int outstandingOpsLimit, boolean shardFound){
+        throttleOperation(operation, outstandingOpsLimit, shardFound, TimeUnit.MILLISECONDS.toNanos(
+                mockActorContext.getDatastoreContext().getOperationTimeoutInMillis()));
+    }
 
-        Assert.assertEquals(1, listMessages.size());
+    private PrimaryShardInfo newPrimaryShardInfo(ActorRef actorRef){
+        return new PrimaryShardInfo(getSystem().actorSelection(actorRef.path()), DataStoreVersions.CURRENT_VERSION,
+                Optional.<DataTree>absent());
+    }
 
-        Assert.assertTrue(listMessages.get(0) instanceof CloseTransaction);
+    private PrimaryShardInfo newPrimaryShardInfo(ActorRef actorRef, Optional<DataTree> dataTreeOptional){
+        return new PrimaryShardInfo(getSystem().actorSelection(actorRef.path()), DataStoreVersions.CURRENT_VERSION,
+                dataTreeOptional);
     }
 
-    private CreateTransactionReply createTransactionReply(ActorRef actorRef){
-        return CreateTransactionReply.newBuilder()
-            .setTransactionActorPath(actorRef.path().toString())
-            .setTransactionId("txn-1")
-            .build();
+
+    private void throttleOperation(TransactionProxyOperation operation, int outstandingOpsLimit, boolean shardFound, long expectedCompletionTime){
+        ActorSystem actorSystem = getSystem();
+        ActorRef shardActorRef = actorSystem.actorOf(Props.create(DoNothingActor.class));
+
+        // 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(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";
+
+        doReturn(incompleteFuture()).when(mockActorContext).
+        executeOperationAsync(eq(actorSystem.actorSelection(shardActorRef.path())),
+                 eqCreateTransaction(memberName, READ_WRITE), any(Timeout.class));
+
+        doReturn(true).when(mockActorContext).isPathLocal(actorPath);
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
+
+        long start = System.nanoTime();
+
+        operation.run(transactionProxy);
+
+        long end = System.nanoTime();
+
+        Assert.assertTrue(String.format("Expected elapsed time: %s. Actual: %s",
+                expectedCompletionTime, (end-start)),
+                ((end - start) > expectedCompletionTime) && ((end - start) < expectedCompletionTime*2));
+
+    }
+
+    private void completeOperation(TransactionProxyOperation operation){
+        completeOperation(operation, true);
+    }
+
+    private void completeOperation(TransactionProxyOperation operation, boolean shardFound){
+        ActorSystem actorSystem = getSystem();
+        ActorRef shardActorRef = actorSystem.actorOf(Props.create(DoNothingActor.class));
+
+        doReturn(actorSystem.actorSelection(shardActorRef.path())).
+                when(mockActorContext).actorSelection(shardActorRef.path().toString());
+
+        if(shardFound) {
+            doReturn(Futures.successful(newPrimaryShardInfo(shardActorRef))).
+                    when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
+        } else {
+            doReturn(Futures.failed(new PrimaryNotFoundException("test")))
+                    .when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
+        }
+
+        ActorRef txActorRef = actorSystem.actorOf(Props.create(DoNothingActor.class));
+        String actorPath = txActorRef.path().toString();
+        CreateTransactionReply createTransactionReply = CreateTransactionReply.newBuilder().
+                setTransactionId("txn-1").setTransactionActorPath(actorPath).
+                setMessageVersion(DataStoreVersions.CURRENT_VERSION).build();
+
+        doReturn(actorSystem.actorSelection(actorPath)).when(mockActorContext).actorSelection(actorPath);
+
+        doReturn(Futures.successful(createTransactionReply)).when(mockActorContext).
+                executeOperationAsync(eq(actorSystem.actorSelection(shardActorRef.path())),
+                        eqCreateTransaction(memberName, READ_WRITE), any(Timeout.class));
+
+        doReturn(true).when(mockActorContext).isPathLocal(anyString());
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, 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, Optional<DataTree> dataTreeOptional){
+        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, dataTreeOptional))).
+                when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, 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 static Optional<DataTree> createDataTree(){
+        DataTree dataTree = mock(DataTree.class);
+        Optional<DataTree> dataTreeOptional = Optional.of(dataTree);
+        DataTreeSnapshot dataTreeSnapshot = mock(DataTreeSnapshot.class);
+        DataTreeModification dataTreeModification = mock(DataTreeModification.class);
+
+        doReturn(dataTreeSnapshot).when(dataTree).takeSnapshot();
+        doReturn(dataTreeModification).when(dataTreeSnapshot).newModification();
+
+        return dataTreeOptional;
+    }
+
+    private static Optional<DataTree> createDataTree(NormalizedNode readResponse){
+        DataTree dataTree = mock(DataTree.class);
+        Optional<DataTree> dataTreeOptional = Optional.of(dataTree);
+        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 dataTreeOptional;
+    }
+
+
+    @Test
+    public void testWriteCompletionForLocalShard(){
+        completeOperationLocal(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+                transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+
+                transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+
+            }
+        }, createDataTree());
+    }
+
+    @Test
+    public void testWriteThrottlingWhenShardFound(){
+        throttleOperation(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+                expectIncompleteBatchedModifications();
+
+                transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+
+                transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+            }
+        });
+    }
+
+    @Test
+    public void testWriteThrottlingWhenShardNotFound(){
+        // Confirm that there is no throttling when the Shard is not found
+        completeOperation(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);
+            }
+        }, false);
+
+    }
+
+
+    @Test
+    public void testWriteCompletion(){
+        completeOperation(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);
+            }
+        });
+    }
+
+    @Test
+    public void testMergeThrottlingWhenShardFound(){
+        throttleOperation(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                NormalizedNode<?, ?> nodeToMerge = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+                expectIncompleteBatchedModifications();
+
+                transactionProxy.merge(TestModel.TEST_PATH, nodeToMerge);
+
+                transactionProxy.merge(TestModel.TEST_PATH, nodeToMerge);
+            }
+        });
+    }
+
+    @Test
+    public void testMergeThrottlingWhenShardNotFound(){
+        completeOperation(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                NormalizedNode<?, ?> nodeToMerge = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+                expectBatchedModifications(2);
+
+                transactionProxy.merge(TestModel.TEST_PATH, nodeToMerge);
+
+                transactionProxy.merge(TestModel.TEST_PATH, nodeToMerge);
+            }
+        }, false);
+    }
+
+    @Test
+    public void testMergeCompletion(){
+        completeOperation(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                NormalizedNode<?, ?> nodeToMerge = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+                expectBatchedModifications(2);
+
+                transactionProxy.merge(TestModel.TEST_PATH, nodeToMerge);
+
+                transactionProxy.merge(TestModel.TEST_PATH, nodeToMerge);
+            }
+        });
+
+    }
+
+    @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(){
+
+        throttleOperation(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                expectIncompleteBatchedModifications();
+
+                transactionProxy.delete(TestModel.TEST_PATH);
+
+                transactionProxy.delete(TestModel.TEST_PATH);
+            }
+        });
+    }
+
+
+    @Test
+    public void testDeleteThrottlingWhenShardNotFound(){
+
+        completeOperation(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                expectBatchedModifications(2);
+
+                transactionProxy.delete(TestModel.TEST_PATH);
+
+                transactionProxy.delete(TestModel.TEST_PATH);
+            }
+        }, 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() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                expectBatchedModifications(2);
+
+                transactionProxy.delete(TestModel.TEST_PATH);
+
+                transactionProxy.delete(TestModel.TEST_PATH);
+            }
+        });
+
+    }
+
+    @Test
+    public void testReadThrottlingWhenShardFound(){
+
+        throttleOperation(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                doReturn(incompleteFuture()).when(mockActorContext).executeOperationAsync(
+                        any(ActorSelection.class), eqReadData());
+
+                transactionProxy.read(TestModel.TEST_PATH);
+
+                transactionProxy.read(TestModel.TEST_PATH);
+            }
+        });
+    }
+
+    @Test
+    public void testReadThrottlingWhenShardNotFound(){
+
+        completeOperation(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                doReturn(incompleteFuture()).when(mockActorContext).executeOperationAsync(
+                        any(ActorSelection.class), eqReadData());
+
+                transactionProxy.read(TestModel.TEST_PATH);
+
+                transactionProxy.read(TestModel.TEST_PATH);
+            }
+        }, false);
+    }
+
+
+    @Test
+    public void testReadCompletion(){
+        completeOperation(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                NormalizedNode<?, ?> nodeToRead = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+                doReturn(readDataReply(nodeToRead)).when(mockActorContext).executeOperationAsync(
+                        any(ActorSelection.class), eqReadData());
+
+                transactionProxy.read(TestModel.TEST_PATH);
+
+                transactionProxy.read(TestModel.TEST_PATH);
+            }
+        });
+
+    }
+
+    @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(){
+
+        throttleOperation(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                doReturn(incompleteFuture()).when(mockActorContext).executeOperationAsync(
+                        any(ActorSelection.class), eqDataExists());
+
+                transactionProxy.exists(TestModel.TEST_PATH);
+
+                transactionProxy.exists(TestModel.TEST_PATH);
+            }
+        });
+    }
+
+    @Test
+    public void testExistsThrottlingWhenShardNotFound(){
+
+        completeOperation(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                doReturn(incompleteFuture()).when(mockActorContext).executeOperationAsync(
+                        any(ActorSelection.class), eqDataExists());
+
+                transactionProxy.exists(TestModel.TEST_PATH);
+
+                transactionProxy.exists(TestModel.TEST_PATH);
+            }
+        }, false);
+    }
+
+
+    @Test
+    public void testExistsCompletion(){
+        completeOperation(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                doReturn(dataExistsReply(true)).when(mockActorContext).executeOperationAsync(
+                        any(ActorSelection.class), eqDataExists());
+
+                transactionProxy.exists(TestModel.TEST_PATH);
+
+                transactionProxy.exists(TestModel.TEST_PATH);
+            }
+        });
+
+    }
+
+    @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(){
+
+        throttleOperation(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+                expectBatchedModifications(1);
+
+                transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+
+                transactionProxy.ready();
+            }
+        });
+    }
+
+    @Test
+    public void testReadyThrottlingWithTwoTransactionContexts(){
+        throttleOperation(new TransactionProxyOperation() {
+            @Override
+            public void run(TransactionProxy transactionProxy) {
+                NormalizedNode<?, ?> nodeToWrite = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+                NormalizedNode<?, ?> carsNode = ImmutableNodes.containerNode(CarsModel.BASE_QNAME);
+
+                expectBatchedModifications(2);
+
+                doReturn(incompleteFuture()).when(mockActorContext).executeOperationAsync(
+                        any(ActorSelection.class), any(ReadyTransaction.class));
+
+                transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);
+
+                // 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();
+            }
+        }, 1, true, TimeUnit.MILLISECONDS.toNanos(mockActorContext.getDatastoreContext().getOperationTimeoutInMillis()) * 2);
+    }
+
+    private void testModificationOperationBatching(TransactionType type) throws Exception {
+        int shardBatchedModificationCount = 3;
+        dataStoreContextBuilder.shardBatchedModificationCount(shardBatchedModificationCount);
+
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), type);
+
+        expectBatchedModifications(actorRef, shardBatchedModificationCount);
+
+        YangInstanceIdentifier writePath1 = TestModel.TEST_PATH;
+        NormalizedNode<?, ?> writeNode1 = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+        YangInstanceIdentifier writePath2 = TestModel.OUTER_LIST_PATH;
+        NormalizedNode<?, ?> writeNode2 = ImmutableNodes.containerNode(TestModel.OUTER_LIST_QNAME);
+
+        YangInstanceIdentifier writePath3 = TestModel.INNER_LIST_PATH;
+        NormalizedNode<?, ?> writeNode3 = ImmutableNodes.containerNode(TestModel.INNER_LIST_QNAME);
+
+        YangInstanceIdentifier mergePath1 = TestModel.TEST_PATH;
+        NormalizedNode<?, ?> mergeNode1 = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+        YangInstanceIdentifier mergePath2 = TestModel.OUTER_LIST_PATH;
+        NormalizedNode<?, ?> mergeNode2 = ImmutableNodes.containerNode(TestModel.OUTER_LIST_QNAME);
+
+        YangInstanceIdentifier mergePath3 = TestModel.INNER_LIST_PATH;
+        NormalizedNode<?, ?> mergeNode3 = ImmutableNodes.containerNode(TestModel.INNER_LIST_QNAME);
+
+        YangInstanceIdentifier deletePath1 = TestModel.TEST_PATH;
+        YangInstanceIdentifier deletePath2 = TestModel.OUTER_LIST_PATH;
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, type);
+
+        transactionProxy.write(writePath1, writeNode1);
+        transactionProxy.write(writePath2, writeNode2);
+        transactionProxy.delete(deletePath1);
+        transactionProxy.merge(mergePath1, mergeNode1);
+        transactionProxy.merge(mergePath2, mergeNode2);
+        transactionProxy.write(writePath3, writeNode3);
+        transactionProxy.merge(mergePath3, mergeNode3);
+        transactionProxy.delete(deletePath2);
+
+        // This sends the last batch.
+        transactionProxy.ready();
+
+        List<BatchedModifications> batchedModifications = captureBatchedModifications(actorRef);
+        assertEquals("Captured BatchedModifications count", 3, batchedModifications.size());
+
+        verifyBatchedModifications(batchedModifications.get(0), false, new WriteModification(writePath1, writeNode1),
+                new WriteModification(writePath2, writeNode2), new DeleteModification(deletePath1));
+
+        verifyBatchedModifications(batchedModifications.get(1), false, new MergeModification(mergePath1, mergeNode1),
+                new MergeModification(mergePath2, mergeNode2), new WriteModification(writePath3, writeNode3));
+
+        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);
+    }
+
+    @Test
+    public void testOptimizedWriteOnlyModificationOperationBatching() throws Throwable {
+        dataStoreContextBuilder.writeOnlyTransactionOptimizationsEnabled(true);
+        testModificationOperationBatching(WRITE_ONLY);
+    }
+
+    @Test
+    public void testModificationOperationBatchingWithInterleavedReads() throws Throwable {
+
+        int shardBatchedModificationCount = 10;
+        dataStoreContextBuilder.shardBatchedModificationCount(shardBatchedModificationCount);
+
+        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);
+
+        expectBatchedModifications(actorRef, shardBatchedModificationCount);
+
+        YangInstanceIdentifier writePath1 = TestModel.TEST_PATH;
+        NormalizedNode<?, ?> writeNode1 = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+        YangInstanceIdentifier writePath2 = TestModel.OUTER_LIST_PATH;
+        NormalizedNode<?, ?> writeNode2 = ImmutableNodes.containerNode(TestModel.OUTER_LIST_QNAME);
+
+        YangInstanceIdentifier mergePath1 = TestModel.TEST_PATH;
+        NormalizedNode<?, ?> mergeNode1 = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
+
+        YangInstanceIdentifier mergePath2 = TestModel.INNER_LIST_PATH;
+        NormalizedNode<?, ?> mergeNode2 = ImmutableNodes.containerNode(TestModel.INNER_LIST_QNAME);
+
+        YangInstanceIdentifier deletePath = TestModel.OUTER_LIST_PATH;
+
+        doReturn(readSerializedDataReply(writeNode2)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedReadData(writePath2));
+
+        doReturn(readSerializedDataReply(mergeNode2)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedReadData(mergePath2));
+
+        doReturn(dataExistsSerializedReply(true)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedDataExists());
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_WRITE);
+
+        transactionProxy.write(writePath1, writeNode1);
+        transactionProxy.write(writePath2, writeNode2);
+
+        Optional<NormalizedNode<?, ?>> readOptional = transactionProxy.read(writePath2).
+                get(5, TimeUnit.SECONDS);
+
+        assertEquals("NormalizedNode isPresent", true, readOptional.isPresent());
+        assertEquals("Response NormalizedNode", writeNode2, readOptional.get());
+
+        transactionProxy.merge(mergePath1, mergeNode1);
+        transactionProxy.merge(mergePath2, mergeNode2);
+
+        readOptional = transactionProxy.read(mergePath2).get(5, TimeUnit.SECONDS);
+
+        transactionProxy.delete(deletePath);
+
+        Boolean exists = transactionProxy.exists(TestModel.TEST_PATH).checkedGet();
+        assertEquals("Exists response", true, exists);
+
+        assertEquals("NormalizedNode isPresent", true, readOptional.isPresent());
+        assertEquals("Response NormalizedNode", mergeNode2, readOptional.get());
+
+        List<BatchedModifications> batchedModifications = captureBatchedModifications(actorRef);
+        assertEquals("Captured BatchedModifications count", 3, batchedModifications.size());
+
+        verifyBatchedModifications(batchedModifications.get(0), false, new WriteModification(writePath1, writeNode1),
+                new WriteModification(writePath2, writeNode2));
+
+        verifyBatchedModifications(batchedModifications.get(1), false, new MergeModification(mergePath1, mergeNode1),
+                new MergeModification(mergePath2, mergeNode2));
+
+        verifyBatchedModifications(batchedModifications.get(2), false, new DeleteModification(deletePath));
+
+        InOrder inOrder = Mockito.inOrder(mockActorContext);
+        inOrder.verify(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), isA(BatchedModifications.class));
+
+        inOrder.verify(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedReadData(writePath2));
+
+        inOrder.verify(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), isA(BatchedModifications.class));
+
+        inOrder.verify(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedReadData(mergePath2));
+
+        inOrder.verify(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), isA(BatchedModifications.class));
+
+        inOrder.verify(mockActorContext).executeOperationAsync(
+                eq(actorSelection(actorRef)), eqSerializedDataExists());
+    }
+
+    @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).when(mockActorContext).getCurrentMemberName();
+
+        doReturn(getSystem().dispatchers().defaultGlobalDispatcher()).when(mockActorContext).getClientDispatcher();
+
+        TransactionProxy transactionProxy = new TransactionProxy(mockComponentFactory, READ_ONLY);
+
+        Optional<NormalizedNode<?, ?>> readOptional = transactionProxy.read(
+                YangInstanceIdentifier.builder().build()).get(5, TimeUnit.SECONDS);
+
+        assertEquals("NormalizedNode isPresent", true, readOptional.isPresent());
+
+        NormalizedNode<?, ?> normalizedNode = readOptional.get();
+
+        assertTrue("Expect value to be a Collection", normalizedNode.getValue() instanceof Collection);
+
+        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));
+
+        doReturn(true).when(mockActorContext).isPathLocal(shardActorRef.path().toString());
+
+        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(readSerializedDataReply(expectedNode)).when(mockActorContext).executeOperationAsync(
+                eq(actorSelection(txActorRef)), eqSerializedReadData(YangInstanceIdentifier.builder().build()));
     }
 }