package org.apache.helix.provisioning;
/*
* 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 java.util.concurrent.TimeUnit;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.GnuParser;
import org.apache.commons.cli.Options;
import org.apache.helix.HelixConnection;
import org.apache.helix.NotificationContext;
import org.apache.helix.api.id.ClusterId;
import org.apache.helix.api.id.ParticipantId;
import org.apache.helix.manager.zk.ZkHelixConnection;
import org.apache.helix.messaging.handling.HelixTaskResult;
import org.apache.helix.messaging.handling.MessageHandler;
import org.apache.helix.messaging.handling.MessageHandlerFactory;
import org.apache.helix.model.Message;
import org.apache.helix.model.Message.MessageType;
import org.apache.helix.participant.AbstractParticipantService;
import org.apache.log4j.Logger;
/**
* Main class that invokes the Participant Api
*/
public class ParticipantLauncher {
private static Logger LOG = Logger.getLogger(ParticipantLauncher.class);
public static void main(String[] args) {
System.out.println("Starting Helix Participant: " + Arrays.toString(args));
Options opts;
opts = new Options();
opts.addOption("cluster", true, "Cluster name, default app name");
opts.addOption("participantId", true, "Participant Id");
opts.addOption("zkAddress", true, "Zookeeper address");
opts.addOption("participantClass", true, "Participant service class");
try {
CommandLine cliParser = new GnuParser().parse(opts, args);
String zkAddress = cliParser.getOptionValue("zkAddress");
final HelixConnection connection = new ZkHelixConnection(zkAddress);
connection.connect();
ClusterId clusterId = ClusterId.from(cliParser.getOptionValue("cluster"));
ParticipantId participantId = ParticipantId.from(cliParser.getOptionValue("participantId"));
String participantClass = cliParser.getOptionValue("participantClass");
@SuppressWarnings("unchecked")
Class<? extends AbstractParticipantService> clazz =
(Class<? extends AbstractParticipantService>) Class.forName(participantClass);
final AbstractParticipantService containerParticipant =
clazz.getConstructor(HelixConnection.class, ClusterId.class, ParticipantId.class)
.newInstance(connection, clusterId, participantId);
containerParticipant.startAsync();
containerParticipant.awaitRunning(60, TimeUnit.SECONDS);
containerParticipant
.getParticipant()
.getMessagingService()
.registerMessageHandlerFactory(MessageType.SHUTDOWN.toString(),
new ShutdownMessageHandlerFactory(containerParticipant, connection));
Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {
@Override
public void run() {
LOG.info("Received a shutdown signal. Stopping participant");
containerParticipant.stopAsync();
containerParticipant.awaitTerminated();
connection.disconnect();
}
}) {
});
Thread.currentThread().join();
} catch (Exception e) {
e.printStackTrace();
System.out.println("Failed to start Helix participant" + e);
// System.exit(1);
}
try {
Thread.currentThread().join();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public static class ShutdownMessageHandlerFactory implements MessageHandlerFactory {
private final AbstractParticipantService _service;
private final HelixConnection _connection;
public ShutdownMessageHandlerFactory(AbstractParticipantService service,
HelixConnection connection) {
_service = service;
_connection = connection;
}
@Override
public MessageHandler createHandler(Message message, NotificationContext context) {
return new ShutdownMessageHandler(_service, _connection, message, context);
}
@Override
public String getMessageType() {
return MessageType.SHUTDOWN.toString();
}
@Override
public void reset() {
}
}
public static class ShutdownMessageHandler extends MessageHandler {
private final AbstractParticipantService _service;
private final HelixConnection _connection;
public ShutdownMessageHandler(AbstractParticipantService service, HelixConnection connection,
Message message, NotificationContext context) {
super(message, context);
_service = service;
_connection = connection;
}
@Override
public HelixTaskResult handleMessage() throws InterruptedException {
LOG.info("Received a shutdown message. Trying to shut down.");
_service.stopAsync();
_service.awaitTerminated();
_connection.disconnect();
LOG.info("Shutdown complete. Process exiting gracefully");
System.exit(0);
return null;
}
@Override
public void onError(Exception e, ErrorCode code, ErrorType type) {
LOG.error("Shutdown message error", e);
}
}
}