package org.apache.helix.agent;
/*
* 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.
*/
import java.util.Arrays;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.GnuParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.OptionBuilder;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import org.apache.helix.HelixManager;
import org.apache.helix.InstanceType;
import org.apache.helix.api.id.StateModelDefId;
import org.apache.helix.manager.zk.ZKHelixManager;
import org.apache.helix.participant.StateMachineEngine;
import org.apache.log4j.Logger;
public class HelixAgentMain {
private static Logger LOG = Logger.getLogger(HelixAgentMain.class);
public static final String zkAddr = "zkSvr";
public static final String cluster = "cluster";
public static final String help = "help";
public static final String instanceName = "instanceName";
public static final String stateModel = "stateModel";
// hack: OptionalBuilder is not thread safe
@SuppressWarnings("static-access")
synchronized private static Options constructCommandLineOptions() {
Option helpOption =
OptionBuilder.withLongOpt(help).withDescription("Prints command-line options info")
.create();
Option zkAddrOption =
OptionBuilder.withLongOpt(zkAddr).hasArgs(1).isRequired(true)
.withArgName("ZookeeperServerAddress(Required)")
.withDescription("Provide zookeeper address").create();
Option clusterOption =
OptionBuilder.withLongOpt(cluster).hasArgs(1).isRequired(true)
.withArgName("Cluster name (Required)").withDescription("Provide cluster name")
.create();
Option instanceNameOption =
OptionBuilder.withLongOpt(instanceName).hasArgs(1).isRequired(true)
.withArgName("Helix agent name (Required)").withDescription("Provide Helix agent name")
.create();
Option stateModelOption =
OptionBuilder.withLongOpt(stateModel).hasArgs(1).isRequired(true)
.withArgName("State model name (Required)").withDescription("Provide state model name")
.create();
Options options = new Options();
options.addOption(helpOption);
options.addOption(zkAddrOption);
options.addOption(clusterOption);
options.addOption(instanceNameOption);
options.addOption(stateModelOption);
return options;
}
public static void printUsage(Options cliOptions) {
HelpFormatter helpFormatter = new HelpFormatter();
helpFormatter.setWidth(1000);
helpFormatter.printHelp("java " + HelixAgentMain.class.getName(), cliOptions);
}
public static CommandLine processCommandLineArgs(String[] cliArgs) throws Exception {
CommandLineParser cliParser = new GnuParser();
Options cliOptions = constructCommandLineOptions();
try {
return cliParser.parse(cliOptions, cliArgs);
} catch (ParseException pe) {
LOG.error("fail to parse command-line options. cliArgs: " + Arrays.toString(cliArgs), pe);
printUsage(cliOptions);
System.exit(1);
}
return null;
}
// NOT working for kill -9, working for kill -2/-15
static class HelixAgentShutdownHook extends Thread {
final HelixManager _manager;
HelixAgentShutdownHook(HelixManager manager) {
_manager = manager;
}
@Override
public void run() {
LOG.info("HelixAgentShutdownHook invoked. agent: " + _manager.getInstanceName());
if (_manager != null && _manager.isConnected())
_manager.disconnect();
}
}
public static void main(String[] args) throws Exception {
CommandLine cmd = processCommandLineArgs(args);
String zkAddress = cmd.getOptionValue(zkAddr);
String clusterName = cmd.getOptionValue(cluster);
String instance = cmd.getOptionValue(instanceName);
String stateModelName = cmd.getOptionValue(stateModel);
HelixManager manager =
new ZKHelixManager(clusterName, instance, InstanceType.PARTICIPANT, zkAddress);
StateMachineEngine stateMach = manager.getStateMachineEngine();
stateMach.registerStateModelFactory(StateModelDefId.from(stateModelName),
new AgentStateModelFactory());
Runtime.getRuntime().addShutdownHook(new HelixAgentShutdownHook(manager));
try {
manager.connect();
Thread.currentThread().join();
} catch (Exception e) {
LOG.error(e);
} finally {
if (manager != null && manager.isConnected()) {
manager.disconnect();
}
}
}
}