/*
*
* 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.hbase.replication.regionserver;
import java.io.IOException;
import java.util.NavigableMap;
import java.util.TreeMap;
import java.util.concurrent.atomic.AtomicBoolean;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.Server;
import org.apache.hadoop.hbase.regionserver.ReplicationSourceService;
import org.apache.hadoop.hbase.regionserver.ReplicationSinkService;
import org.apache.hadoop.hbase.regionserver.wal.HLog;
import org.apache.hadoop.hbase.regionserver.wal.HLogKey;
import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
import org.apache.hadoop.hbase.regionserver.wal.WALActionsListener;
import org.apache.hadoop.hbase.replication.ReplicationZookeeper;
import org.apache.hadoop.hbase.replication.master.ReplicationLogCleaner;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.zookeeper.KeeperException;
import static org.apache.hadoop.hbase.HConstants.HBASE_MASTER_LOGCLEANER_PLUGINS;
import static org.apache.hadoop.hbase.HConstants.REPLICATION_ENABLE_KEY;
import static org.apache.hadoop.hbase.HConstants.REPLICATION_SCOPE_LOCAL;
/**
* Gateway to Replication. Used by {@link org.apache.hadoop.hbase.regionserver.HRegionServer}.
*/
@InterfaceAudience.Private
public class Replication implements WALActionsListener,
ReplicationSourceService, ReplicationSinkService {
private boolean replication;
private ReplicationSourceManager replicationManager;
private final AtomicBoolean replicating = new AtomicBoolean(true);
private ReplicationZookeeper zkHelper;
private Configuration conf;
private ReplicationSink replicationSink;
// Hosting server
private Server server;
/**
* Instantiate the replication management (if rep is enabled).
* @param server Hosting server
* @param fs handle to the filesystem
* @param logDir
* @param oldLogDir directory where logs are archived
* @throws IOException
*/
public Replication(final Server server, final FileSystem fs,
final Path logDir, final Path oldLogDir) throws IOException{
initialize(server, fs, logDir, oldLogDir);
}
/**
* Empty constructor
*/
public Replication() {
}
public void initialize(final Server server, final FileSystem fs,
final Path logDir, final Path oldLogDir) throws IOException {
this.server = server;
this.conf = this.server.getConfiguration();
this.replication = isReplication(this.conf);
if (replication) {
try {
this.zkHelper = new ReplicationZookeeper(server, this.replicating);
} catch (KeeperException ke) {
throw new IOException("Failed replication handler create " +
"(replicating=" + this.replicating, ke);
}
this.replicationManager = new ReplicationSourceManager(zkHelper, conf, this.server, fs,
this.replicating, logDir, oldLogDir);
} else {
this.replicationManager = null;
this.zkHelper = null;
}
}
/**
* @param c Configuration to look at
* @return True if replication is enabled.
*/
public static boolean isReplication(final Configuration c) {
return c.getBoolean(REPLICATION_ENABLE_KEY, false);
}
/*
* Returns an object to listen to new hlog changes
**/
public WALActionsListener getWALActionsListener() {
return this;
}
/**
* Stops replication service.
*/
public void stopReplicationService() {
join();
}
/**
* Join with the replication threads
*/
public void join() {
if (this.replication) {
this.replicationManager.join();
this.replicationSink.stopReplicationSinkServices();
}
}
/**
* Carry on the list of log entries down to the sink
* @param entries list of entries to replicate
* @throws IOException
*/
public void replicateLogEntries(HLog.Entry[] entries) throws IOException {
if (this.replication) {
this.replicationSink.replicateEntries(entries);
}
}
/**
* If replication is enabled and this cluster is a master,
* it starts
* @throws IOException
*/
public void startReplicationService() throws IOException {
if (this.replication) {
this.replicationManager.init();
this.replicationSink = new ReplicationSink(this.conf, this.server);
}
}
/**
* Get the replication sources manager
* @return the manager if replication is enabled, else returns false
*/
public ReplicationSourceManager getReplicationManager() {
return this.replicationManager;
}
@Override
public void visitLogEntryBeforeWrite(HRegionInfo info, HLogKey logKey,
WALEdit logEdit) {
// Not interested
}
@Override
public void visitLogEntryBeforeWrite(HTableDescriptor htd, HLogKey logKey,
WALEdit logEdit) {
NavigableMap<byte[], Integer> scopes =
new TreeMap<byte[], Integer>(Bytes.BYTES_COMPARATOR);
byte[] family;
for (KeyValue kv : logEdit.getKeyValues()) {
family = kv.getFamily();
int scope = htd.getFamily(family).getScope();
if (scope != REPLICATION_SCOPE_LOCAL &&
!scopes.containsKey(family)) {
scopes.put(family, scope);
}
}
if (!scopes.isEmpty()) {
logEdit.setScopes(scopes);
}
}
@Override
public void preLogRoll(Path oldPath, Path newPath) throws IOException {
getReplicationManager().preLogRoll(newPath);
}
@Override
public void postLogRoll(Path oldPath, Path newPath) throws IOException {
getReplicationManager().postLogRoll(newPath);
}
@Override
public void preLogArchive(Path oldPath, Path newPath) throws IOException {
// Not interested
}
@Override
public void postLogArchive(Path oldPath, Path newPath) throws IOException {
// Not interested
}
/**
* This method modifies the master's configuration in order to inject
* replication-related features
* @param conf
*/
public static void decorateMasterConfiguration(Configuration conf) {
if (!isReplication(conf)) {
return;
}
String plugins = conf.get(HBASE_MASTER_LOGCLEANER_PLUGINS);
if (!plugins.contains(ReplicationLogCleaner.class.toString())) {
conf.set(HBASE_MASTER_LOGCLEANER_PLUGINS,
plugins + "," + ReplicationLogCleaner.class.getCanonicalName());
}
}
@Override
public void logRollRequested() {
// Not interested
}
@Override
public void logCloseRequested() {
// not interested
}
}