/**
*
* 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.master;
import java.io.File;
import java.io.IOException;
import java.util.List;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.GnuParser;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.ZNodeClearer;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.LocalHBaseCluster;
import org.apache.hadoop.hbase.MasterNotRunningException;
import org.apache.hadoop.hbase.ZooKeeperConnectionException;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.regionserver.HRegionServer;
import org.apache.hadoop.hbase.util.JVMClusterUtil;
import org.apache.hadoop.hbase.util.ServerCommandLine;
import org.apache.hadoop.hbase.zookeeper.MiniZooKeeperCluster;
import org.apache.zookeeper.KeeperException;
@InterfaceAudience.Private
public class HMasterCommandLine extends ServerCommandLine {
private static final Log LOG = LogFactory.getLog(HMasterCommandLine.class);
private static final String USAGE =
"Usage: Master [opts] start|stop|clear\n" +
" start Start Master. If local mode, start Master and RegionServer in same JVM\n" +
" stop Start cluster shutdown; Master signals RegionServer shutdown\n" +
" clear Delete the master znode in ZooKeeper after a master crashes\n "+
" where [opts] are:\n" +
" --minServers=<servers> Minimum RegionServers needed to host user tables.\n" +
" --backup Master should start in backup mode";
private final Class<? extends HMaster> masterClass;
public HMasterCommandLine(Class<? extends HMaster> masterClass) {
this.masterClass = masterClass;
}
protected String getUsage() {
return USAGE;
}
public int run(String args[]) throws Exception {
Options opt = new Options();
opt.addOption("minServers", true, "Minimum RegionServers needed to host user tables");
opt.addOption("backup", false, "Do not try to become HMaster until the primary fails");
CommandLine cmd;
try {
cmd = new GnuParser().parse(opt, args);
} catch (ParseException e) {
LOG.error("Could not parse: ", e);
usage(null);
return -1;
}
if (cmd.hasOption("minServers")) {
String val = cmd.getOptionValue("minServers");
getConf().setInt("hbase.regions.server.count.min",
Integer.valueOf(val));
LOG.debug("minServers set to " + val);
}
// check if we are the backup master - override the conf if so
if (cmd.hasOption("backup")) {
getConf().setBoolean(HConstants.MASTER_TYPE_BACKUP, true);
}
List<String> remainingArgs = cmd.getArgList();
if (remainingArgs.size() != 1) {
usage(null);
return -1;
}
String command = remainingArgs.get(0);
if ("start".equals(command)) {
return startMaster();
} else if ("stop".equals(command)) {
return stopMaster();
} else if ("clear".equals(command)) {
return (ZNodeClearer.clear(getConf()) ? 0 : -1);
} else {
usage("Invalid command: " + command);
return -1;
}
}
private int startMaster() {
Configuration conf = getConf();
try {
// If 'local', defer to LocalHBaseCluster instance. Starts master
// and regionserver both in the one JVM.
if (LocalHBaseCluster.isLocal(conf)) {
final MiniZooKeeperCluster zooKeeperCluster =
new MiniZooKeeperCluster();
File zkDataPath = new File(conf.get(HConstants.ZOOKEEPER_DATA_DIR));
int zkClientPort = conf.getInt(HConstants.ZOOKEEPER_CLIENT_PORT, 0);
if (zkClientPort == 0) {
throw new IOException("No config value for "
+ HConstants.ZOOKEEPER_CLIENT_PORT);
}
zooKeeperCluster.setDefaultClientPort(zkClientPort);
int clientPort = zooKeeperCluster.startup(zkDataPath);
if (clientPort != zkClientPort) {
String errorMsg = "Could not start ZK at requested port of " +
zkClientPort + ". ZK was started at port: " + clientPort +
". Aborting as clients (e.g. shell) will not be able to find " +
"this ZK quorum.";
System.err.println(errorMsg);
throw new IOException(errorMsg);
}
conf.set(HConstants.ZOOKEEPER_CLIENT_PORT,
Integer.toString(clientPort));
// Need to have the zk cluster shutdown when master is shutdown.
// Run a subclass that does the zk cluster shutdown on its way out.
LocalHBaseCluster cluster = new LocalHBaseCluster(conf, 1, 1,
LocalHMaster.class, HRegionServer.class);
((LocalHMaster)cluster.getMaster(0)).setZKCluster(zooKeeperCluster);
cluster.startup();
waitOnMasterThreads(cluster);
} else {
HMaster master = HMaster.constructMaster(masterClass, conf);
if (master.isStopped()) {
LOG.info("Won't bring the Master up as a shutdown is requested");
return -1;
}
master.start();
master.join();
if(master.isAborted())
throw new RuntimeException("HMaster Aborted");
}
} catch (Throwable t) {
LOG.error("Failed to start master", t);
return -1;
}
return 0;
}
private int stopMaster() {
HBaseAdmin adm = null;
try {
Configuration conf = getConf();
// Don't try more than once
conf.setInt("hbase.client.retries.number", 1);
adm = new HBaseAdmin(getConf());
} catch (MasterNotRunningException e) {
LOG.error("Master not running");
return -1;
} catch (ZooKeeperConnectionException e) {
LOG.error("ZooKeeper not available");
return -1;
}
try {
adm.shutdown();
} catch (Throwable t) {
LOG.error("Failed to stop master", t);
return -1;
}
return 0;
}
private void waitOnMasterThreads(LocalHBaseCluster cluster) throws InterruptedException{
List<JVMClusterUtil.MasterThread> masters = cluster.getMasters();
List<JVMClusterUtil.RegionServerThread> regionservers = cluster.getRegionServers();
if (masters != null) {
for (JVMClusterUtil.MasterThread t : masters) {
t.join();
if(t.getMaster().isAborted()) {
closeAllRegionServerThreads(regionservers);
throw new RuntimeException("HMaster Aborted");
}
}
}
}
private static void closeAllRegionServerThreads(List<JVMClusterUtil.RegionServerThread> regionservers) {
for(JVMClusterUtil.RegionServerThread t : regionservers){
t.getRegionServer().stop("HMaster Aborted; Bringing down regions servers");
}
}
/*
* Version of master that will shutdown the passed zk cluster on its way out.
*/
public static class LocalHMaster extends HMaster {
private MiniZooKeeperCluster zkcluster = null;
public LocalHMaster(Configuration conf)
throws IOException, KeeperException, InterruptedException {
super(conf);
}
@Override
public void run() {
super.run();
if (this.zkcluster != null) {
try {
this.zkcluster.shutdown();
} catch (IOException e) {
e.printStackTrace();
}
}
}
void setZKCluster(final MiniZooKeeperCluster zkcluster) {
this.zkcluster = zkcluster;
}
}
}