package org.apache.helix.examples;
/*
* 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 org.apache.helix.HelixManager;
import org.apache.helix.HelixManagerFactory;
import org.apache.helix.InstanceType;
import org.apache.helix.NotificationContext;
import org.apache.helix.model.Message;
import org.apache.helix.participant.StateMachineEngine;
import org.apache.helix.participant.statemachine.StateModel;
import org.apache.helix.participant.statemachine.StateModelFactory;
import org.apache.helix.participant.statemachine.StateModelInfo;
import org.apache.helix.participant.statemachine.Transition;
public class DummyParticipant
{
// dummy master-slave state model
@StateModelInfo(initialState = "OFFLINE", states = { "MASTER", "SLAVE", "ERROR" })
public static class DummyMSStateModel extends StateModel
{
@Transition(to = "SLAVE", from = "OFFLINE")
public void onBecomeSlaveFromOffline(Message message, NotificationContext context)
{
String partitionName = message.getPartitionName();
String instanceName = message.getTgtName();
System.out.println(instanceName + " becomes SLAVE from OFFLINE for " + partitionName);
}
@Transition(to = "MASTER", from = "SLAVE")
public void onBecomeMasterFromSlave(Message message, NotificationContext context)
{
String partitionName = message.getPartitionName();
String instanceName = message.getTgtName();
System.out.println(instanceName + " becomes MASTER from SLAVE for " + partitionName);
}
@Transition(to = "SLAVE", from = "MASTER")
public void onBecomeSlaveFromMaster(Message message, NotificationContext context)
{
String partitionName = message.getPartitionName();
String instanceName = message.getTgtName();
System.out.println(instanceName + " becomes SLAVE from MASTER for " + partitionName);
}
@Transition(to = "OFFLINE", from = "SLAVE")
public void onBecomeOfflineFromSlave(Message message, NotificationContext context)
{
String partitionName = message.getPartitionName();
String instanceName = message.getTgtName();
System.out.println(instanceName + " becomes OFFLINE from SLAVE for " + partitionName);
}
@Transition(to = "DROPPED", from = "OFFLINE")
public void onBecomeDroppedFromOffline(Message message, NotificationContext context)
{
String partitionName = message.getPartitionName();
String instanceName = message.getTgtName();
System.out.println(instanceName + " becomes DROPPED from OFFLINE for " + partitionName);
}
@Transition(to = "OFFLINE", from = "ERROR")
public void onBecomeOfflineFromError(Message message, NotificationContext context)
{
String partitionName = message.getPartitionName();
String instanceName = message.getTgtName();
System.out.println(instanceName + " becomes OFFLINE from ERROR for " + partitionName);
}
@Override
public void reset()
{
System.out.println("Default MockMSStateModel.reset() invoked");
}
}
// dummy master slave state model factory
public static class DummyMSModelFactory extends StateModelFactory<DummyMSStateModel>
{
@Override
public DummyMSStateModel createNewStateModel(String partitionName)
{
DummyMSStateModel model = new DummyMSStateModel();
return model;
}
}
public static void main(String[] args)
{
if (args.length < 3)
{
System.err.println("USAGE: DummyParticipant zkAddress clusterName instanceName");
System.exit(1);
}
String zkAddr = args[0];
String clusterName = args[1];
String instanceName = args[2];
HelixManager manager = null;
try
{
manager = HelixManagerFactory.getZKHelixManager(clusterName, instanceName,
InstanceType.PARTICIPANT, zkAddr);
StateMachineEngine stateMach = manager.getStateMachineEngine();
DummyMSModelFactory msModelFactory = new DummyMSModelFactory();
stateMach.registerStateModelFactory("MasterSlave", msModelFactory);
manager.connect();
Thread.currentThread().join();
} catch (Exception e)
{
// TODO Auto-generated catch block
e.printStackTrace();
} finally
{
if (manager != null)
{
manager.disconnect();
}
}
}
}