diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 3c639f696f..55f69afe49 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -120,6 +120,8 @@ Trunk (Unreleased)
HDFS-4633 TestDFSClientExcludedNodes fails sporadically if excluded nodes
cache expires too quickly (Chris Nauroth via Sanjay)
+ HDFS-4904. Remove JournalService. (Arpit Agarwal via cnauroth)
+
OPTIMIZATIONS
BUG FIXES
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/journalservice/JournalListener.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/journalservice/JournalListener.java
deleted file mode 100644
index 2d5ec9e986..0000000000
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/journalservice/JournalListener.java
+++ /dev/null
@@ -1,64 +0,0 @@
-/**
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements. See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership. The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.hadoop.hdfs.server.journalservice;
-
-import java.io.IOException;
-
-import org.apache.hadoop.hdfs.server.protocol.JournalProtocol;
-import org.apache.hadoop.hdfs.server.protocol.NamespaceInfo;
-
-/**
- * JournalListener is a callback interface to handle journal records
- * received from the namenode.
- */
-public interface JournalListener {
- /**
- * Check the namespace information returned by a namenode
- * @param service service that is making the callback
- * @param info returned namespace information from the namenode
- *
- * The application using {@link JournalService} can stop the service if
- * {@code info} validation fails.
- */
- public void verifyVersion(JournalService service, NamespaceInfo info);
-
- /**
- * Process the received Journal record
- * @param service {@link JournalService} making the callback
- * @param firstTxnId first transaction Id in the journal
- * @param numTxns number of records
- * @param records journal records
- * @throws IOException on error
- *
- * Any IOException thrown from the listener is thrown back in
- * {@link JournalProtocol#journal}
- */
- public void journal(JournalService service, long firstTxnId, int numTxns,
- byte[] records) throws IOException;
-
- /**
- * Roll the editlog
- * @param service {@link JournalService} making the callback
- * @param txid transaction ID to roll at
- *
- * Any IOException thrown from the listener is thrown back in
- * {@link JournalProtocol#startLogSegment}
- */
- public void startLogSegment(JournalService service, long txid) throws IOException;
-}
\ No newline at end of file
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/journalservice/JournalService.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/journalservice/JournalService.java
deleted file mode 100644
index 4764259506..0000000000
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/journalservice/JournalService.java
+++ /dev/null
@@ -1,366 +0,0 @@
-/**
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements. See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership. The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.hadoop.hdfs.server.journalservice;
-
-import java.io.IOException;
-import java.net.InetSocketAddress;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hdfs.NameNodeProxies;
-import org.apache.hadoop.hdfs.protocol.LayoutVersion;
-import org.apache.hadoop.hdfs.protocol.UnregisteredNodeException;
-import org.apache.hadoop.hdfs.protocol.proto.JournalProtocolProtos.JournalProtocolService;
-import org.apache.hadoop.hdfs.protocolPB.JournalProtocolPB;
-import org.apache.hadoop.hdfs.protocolPB.JournalProtocolServerSideTranslatorPB;
-import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.NamenodeRole;
-import org.apache.hadoop.hdfs.server.common.StorageInfo;
-import org.apache.hadoop.hdfs.server.protocol.FenceResponse;
-import org.apache.hadoop.hdfs.server.protocol.FencedException;
-import org.apache.hadoop.hdfs.server.protocol.JournalInfo;
-import org.apache.hadoop.hdfs.server.protocol.JournalProtocol;
-import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocol;
-import org.apache.hadoop.hdfs.server.protocol.NamenodeRegistration;
-import org.apache.hadoop.hdfs.server.protocol.NamespaceInfo;
-import org.apache.hadoop.ipc.ProtobufRpcEngine;
-import org.apache.hadoop.ipc.RPC;
-import org.apache.hadoop.net.NetUtils;
-import org.apache.hadoop.security.UserGroupInformation;
-
-import com.google.common.annotations.VisibleForTesting;
-import com.google.protobuf.BlockingService;
-
-/**
- * This class interfaces with the namenode using {@link JournalProtocol} over
- * RPC. It has two modes:
- *
- * - Mode where an RPC.Server is provided from outside, on which it
- * {@link JournalProtocol} is registered. The RPC.Server stop and start is
- * managed outside by the application.
- * - Stand alone mode where an RPC.Server is started and managed by the
- * JournalListener.
- *
- *
- * The received journal operations are sent to a listener over callbacks. The
- * listener implementation can handle the callbacks based on the application
- * requirement.
- */
-public class JournalService implements JournalProtocol {
- public static final Log LOG = LogFactory.getLog(JournalService.class.getName());
-
- private final JournalListener listener;
- private final InetSocketAddress nnAddress;
- private final NamenodeRegistration registration;
- private final NamenodeProtocol namenode;
- private final StateHandler stateHandler = new StateHandler();
- private final RPC.Server rpcServer;
- private long epoch = 0;
- private String fencerInfo;
-
- enum State {
- /** The service is initialized and ready to start. */
- INIT(false, false),
- /**
- * RPC server is started.
- * The service is ready to receive requests from namenode.
- */
- STARTED(false, false),
- /** The service is fenced by a namenode and waiting for roll. */
- WAITING_FOR_ROLL(false, true),
- /**
- * The existing log is syncing with another source
- * and it accepts journal from Namenode.
- */
- SYNCING(true, true),
- /** The existing log is in sync and it accepts journal from Namenode. */
- IN_SYNC(true, true),
- /** The service is stopped. */
- STOPPED(false, false);
-
- final boolean isJournalAllowed;
- final boolean isStartLogSegmentAllowed;
-
- State(boolean isJournalAllowed, boolean isStartLogSegmentAllowed) {
- this.isJournalAllowed = isJournalAllowed;
- this.isStartLogSegmentAllowed = isStartLogSegmentAllowed;
- }
- }
-
- static class StateHandler {
- State current = State.INIT;
-
- synchronized void start() {
- if (current != State.INIT) {
- throw new IllegalStateException("Service cannot be started in "
- + current + " state.");
- }
- current = State.STARTED;
- }
-
- synchronized void waitForRoll() {
- if (current != State.STARTED) {
- throw new IllegalStateException("Cannot wait-for-roll in " + current
- + " state.");
- }
- current = State.WAITING_FOR_ROLL;
- }
-
- synchronized void startLogSegment() {
- if (current == State.WAITING_FOR_ROLL) {
- current = State.SYNCING;
- }
- }
-
- synchronized void isStartLogSegmentAllowed() throws IOException {
- if (!current.isStartLogSegmentAllowed) {
- throw new IOException("Cannot start log segment in " + current
- + " state.");
- }
- }
-
- synchronized void isJournalAllowed() throws IOException {
- if (!current.isJournalAllowed) {
- throw new IOException("Cannot journal in " + current + " state.");
- }
- }
-
- synchronized boolean isStopped() {
- if (current == State.STOPPED) {
- LOG.warn("Ignore stop request since the service is in " + current
- + " state.");
- return true;
- }
- current = State.STOPPED;
- return false;
- }
- }
-
- /**
- * Constructor to create {@link JournalService} where an RPC server is
- * created by this service.
- * @param conf Configuration
- * @param nnAddr host:port for the active Namenode's RPC server
- * @param serverAddress address to start RPC server to receive
- * {@link JournalProtocol} requests. This can be null, if
- * {@code server} is a valid server that is managed out side this
- * service.
- * @param listener call-back interface to listen to journal activities
- * @throws IOException on error
- */
- JournalService(Configuration conf, InetSocketAddress nnAddr,
- InetSocketAddress serverAddress, JournalListener listener)
- throws IOException {
- this.nnAddress = nnAddr;
- this.listener = listener;
- this.namenode = NameNodeProxies.createNonHAProxy(conf, nnAddr,
- NamenodeProtocol.class, UserGroupInformation.getCurrentUser(), true)
- .getProxy();
- this.rpcServer = createRpcServer(conf, serverAddress, this);
-
- String addr = NetUtils.getHostPortString(rpcServer.getListenerAddress());
- StorageInfo storage = new StorageInfo(
- LayoutVersion.getCurrentLayoutVersion(), 0, "", 0);
- registration = new NamenodeRegistration(addr, "", storage,
- NamenodeRole.BACKUP);
- }
-
- /**
- * Start the service.
- */
- public void start() {
- stateHandler.start();
-
- // Start the RPC server
- LOG.info("Starting rpc server");
- rpcServer.start();
-
- for(boolean registered = false, handshakeComplete = false; ; ) {
- try {
- // Perform handshake
- if (!handshakeComplete) {
- handshake();
- handshakeComplete = true;
- LOG.info("handshake completed");
- }
-
- // Register with the namenode
- if (!registered) {
- registerWithNamenode();
- registered = true;
- LOG.info("Registration completed");
- break;
- }
- } catch (IOException ioe) {
- LOG.warn("Encountered exception ", ioe);
- } catch (Exception e) {
- LOG.warn("Encountered exception ", e);
- }
-
- try {
- Thread.sleep(1000);
- } catch (InterruptedException ie) {
- LOG.warn("Encountered exception ", ie);
- }
- }
-
- stateHandler.waitForRoll();
- try {
- namenode.rollEditLog();
- } catch (IOException e) {
- LOG.warn("Encountered exception ", e);
- }
- }
-
- /**
- * Stop the service. For application with RPC Server managed outside, the
- * RPC Server must be stopped the application.
- */
- public void stop() {
- if (!stateHandler.isStopped()) {
- rpcServer.stop();
- }
- }
-
- @Override
- public void journal(JournalInfo journalInfo, long epoch, long firstTxnId,
- int numTxns, byte[] records) throws IOException {
- if (LOG.isTraceEnabled()) {
- LOG.trace("Received journal " + firstTxnId + " " + numTxns);
- }
- stateHandler.isJournalAllowed();
- verify(epoch, journalInfo);
- listener.journal(this, firstTxnId, numTxns, records);
- }
-
- @Override
- public void startLogSegment(JournalInfo journalInfo, long epoch, long txid)
- throws IOException {
- if (LOG.isTraceEnabled()) {
- LOG.trace("Received startLogSegment " + txid);
- }
- stateHandler.isStartLogSegmentAllowed();
- verify(epoch, journalInfo);
- listener.startLogSegment(this, txid);
- stateHandler.startLogSegment();
- }
-
- @Override
- public FenceResponse fence(JournalInfo journalInfo, long epoch,
- String fencerInfo) throws IOException {
- LOG.info("Fenced by " + fencerInfo + " with epoch " + epoch);
- verifyFence(epoch, fencerInfo);
- verify(journalInfo);
- long previousEpoch = epoch;
- this.epoch = epoch;
- this.fencerInfo = fencerInfo;
-
- // TODO:HDFS-3092 set lastTransId and inSync
- return new FenceResponse(previousEpoch, 0, false);
- }
-
- /** Create an RPC server. */
- private static RPC.Server createRpcServer(Configuration conf,
- InetSocketAddress address, JournalProtocol impl) throws IOException {
- RPC.setProtocolEngine(conf, JournalProtocolPB.class,
- ProtobufRpcEngine.class);
- JournalProtocolServerSideTranslatorPB xlator =
- new JournalProtocolServerSideTranslatorPB(impl);
- BlockingService service =
- JournalProtocolService.newReflectiveBlockingService(xlator);
- return new RPC.Builder(conf).setProtocol(JournalProtocolPB.class)
- .setInstance(service).setBindAddress(address.getHostName())
- .setPort(address.getPort()).setNumHandlers(1).setVerbose(false).build();
- }
-
- private void verifyEpoch(long e) throws FencedException {
- if (epoch != e) {
- String errorMsg = "Epoch " + e + " is not valid. "
- + "Resource has already been fenced by " + fencerInfo
- + " with epoch " + epoch;
- LOG.warn(errorMsg);
- throw new FencedException(errorMsg);
- }
- }
-
- private void verifyFence(long e, String fencer) throws FencedException {
- if (e <= epoch) {
- String errorMsg = "Epoch " + e + " from fencer " + fencer
- + " is not valid. " + "Resource has already been fenced by "
- + fencerInfo + " with epoch " + epoch;
- LOG.warn(errorMsg);
- throw new FencedException(errorMsg);
- }
- }
-
- /**
- * Verifies a journal request
- */
- private void verify(JournalInfo journalInfo) throws IOException {
- String errorMsg = null;
- int expectedNamespaceID = registration.getNamespaceID();
- if (journalInfo.getNamespaceId() != expectedNamespaceID) {
- errorMsg = "Invalid namespaceID in journal request - expected " + expectedNamespaceID
- + " actual " + journalInfo.getNamespaceId();
- LOG.warn(errorMsg);
- throw new UnregisteredNodeException(journalInfo);
- }
- if (!journalInfo.getClusterId().equals(registration.getClusterID())) {
- errorMsg = "Invalid clusterId in journal request - expected "
- + journalInfo.getClusterId() + " actual " + registration.getClusterID();
- LOG.warn(errorMsg);
- throw new UnregisteredNodeException(journalInfo);
- }
- }
-
- /**
- * Verifies a journal request
- */
- private void verify(long e, JournalInfo journalInfo) throws IOException {
- verifyEpoch(e);
- verify(journalInfo);
- }
-
- /**
- * Register this service with the active namenode.
- */
- private void registerWithNamenode() throws IOException {
- NamenodeRegistration nnReg = namenode.register(registration);
- String msg = null;
- if(nnReg == null) { // consider as a rejection
- msg = "Registration rejected by " + nnAddress;
- } else if(!nnReg.isRole(NamenodeRole.NAMENODE)) {
- msg = " Name-node " + nnAddress + " is not active";
- }
- if(msg != null) {
- LOG.error(msg);
- throw new IOException(msg); // stop the node
- }
- }
-
- private void handshake() throws IOException {
- NamespaceInfo nsInfo = namenode.versionRequest();
- listener.verifyVersion(this, nsInfo);
- registration.setStorageInfo(nsInfo);
- }
-
- @VisibleForTesting
- long getEpoch() {
- return epoch;
- }
-}
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/journalservice/TestJournalService.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/journalservice/TestJournalService.java
deleted file mode 100644
index 41a4fe4555..0000000000
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/journalservice/TestJournalService.java
+++ /dev/null
@@ -1,127 +0,0 @@
-/**
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements. See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership. The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.apache.hadoop.hdfs.server.journalservice;
-
-import static org.junit.Assert.assertNotNull;
-
-import java.io.IOException;
-import java.net.InetSocketAddress;
-
-import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.fs.FileSystem;
-import org.apache.hadoop.fs.FileSystemTestHelper;
-import org.apache.hadoop.fs.Path;
-import org.apache.hadoop.hdfs.HdfsConfiguration;
-import org.apache.hadoop.hdfs.MiniDFSCluster;
-import org.apache.hadoop.hdfs.server.namenode.NameNode;
-import org.apache.hadoop.hdfs.server.protocol.FenceResponse;
-import org.apache.hadoop.hdfs.server.protocol.FencedException;
-import org.apache.hadoop.hdfs.server.protocol.JournalInfo;
-import org.junit.Test;
-import org.mockito.Mockito;
-
-/**
- * Tests for {@link JournalService}
- */
-public class TestJournalService {
- private MiniDFSCluster cluster;
- private Configuration conf = new HdfsConfiguration();
-
- /**
- * Test calls backs {@link JournalListener#startLogSegment(JournalService, long)} and
- * {@link JournalListener#journal(JournalService, long, int, byte[])} are
- * called.
- */
- @Test
- public void testCallBacks() throws Exception {
- JournalListener listener = Mockito.mock(JournalListener.class);
- JournalService service = null;
- try {
- cluster = new MiniDFSCluster.Builder(conf).numDataNodes(1).build();
- cluster.waitActive(0);
- service = startJournalService(listener);
- verifyRollLogsCallback(service, listener);
- verifyJournalCallback(service, listener);
- verifyFence(service, cluster.getNameNode(0));
- } finally {
- if (service != null) {
- service.stop();
- }
- if (cluster != null) {
- cluster.shutdown();
- }
- }
- }
-
- private JournalService startJournalService(JournalListener listener)
- throws IOException {
- InetSocketAddress nnAddr = cluster.getNameNode(0).getNameNodeAddress();
- InetSocketAddress serverAddr = new InetSocketAddress(0);
- JournalService service = new JournalService(conf, nnAddr, serverAddr,
- listener);
- service.start();
- return service;
- }
-
- /**
- * Starting {@link JournalService} should result in Namenode calling
- * {@link JournalService#startLogSegment}, resulting in callback
- * {@link JournalListener#rollLogs}
- */
- private void verifyRollLogsCallback(JournalService s, JournalListener l)
- throws IOException {
- Mockito.verify(l, Mockito.times(1)).startLogSegment(Mockito.eq(s), Mockito.anyLong());
- }
-
- /**
- * File system write operations should result in JournalListener call
- * backs.
- */
- private void verifyJournalCallback(JournalService s, JournalListener l) throws IOException {
- Path fileName = new Path("/tmp/verifyJournalCallback");
- FileSystem fs = cluster.getFileSystem();
- FileSystemTestHelper.createFile(fs, fileName);
- fs.delete(fileName, true);
- Mockito.verify(l, Mockito.atLeastOnce()).journal(Mockito.eq(s),
- Mockito.anyLong(), Mockito.anyInt(), (byte[]) Mockito.any());
- }
-
- public void verifyFence(JournalService s, NameNode nn) throws Exception {
- String cid = nn.getNamesystem().getClusterId();
- int nsId = nn.getNamesystem().getFSImage().getNamespaceID();
- int lv = nn.getNamesystem().getFSImage().getLayoutVersion();
-
- // Fence the journal service
- JournalInfo info = new JournalInfo(lv, cid, nsId);
- long currentEpoch = s.getEpoch();
-
- // New epoch lower than the current epoch is rejected
- try {
- s.fence(info, (currentEpoch - 1), "fencer");
- } catch (FencedException ignore) { /* Ignored */ }
-
- // New epoch equal to the current epoch is rejected
- try {
- s.fence(info, currentEpoch, "fencer");
- } catch (FencedException ignore) { /* Ignored */ }
-
- // New epoch higher than the current epoch is successful
- FenceResponse resp = s.fence(info, currentEpoch+1, "fencer");
- assertNotNull(resp);
- }
-}
\ No newline at end of file