/*
* Copyright [2013-2014] PayPal Software Foundation
*
* Licensed 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 ml.shifu.guagua.worker;
import ml.shifu.guagua.InMemoryCoordinator;
import ml.shifu.guagua.io.Bytable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* {@link LocalWorkerCoordinator} is local coordinator implementation in one jvm instance.
*
* <p>
* {@link LocalWorkerCoordinator} is a proxy and {@link #coordinator} has the real logic to coordinate master and
* workers. {@link #coordinator} should be set by using the same instance with InternalWorkerCoordinator.
*
* @param <MASTER_RESULT>
* master result for computation in each iteration.
* @param <WORKER_RESULT>
* worker result for computation in each iteration.
*/
public class LocalWorkerCoordinator<MASTER_RESULT extends Bytable, WORKER_RESULT extends Bytable> extends
BasicWorkerInterceptor<MASTER_RESULT, WORKER_RESULT> {
private static final Logger LOG = LoggerFactory.getLogger(LocalWorkerCoordinator.class);
/**
* Real in memory coordinator implementation.
*/
private InMemoryCoordinator<MASTER_RESULT, WORKER_RESULT> coordinator;
@Override
public void preApplication(WorkerContext<MASTER_RESULT, WORKER_RESULT> context) {
this.coordinator.signalMaster(context.getCurrentIteration(), Integer.parseInt(context.getContainerId()) - 1,
null);
LOG.info("Worker {} is initilized.", context.getContainerId());
this.coordinator.awaitMaster(context.getCurrentIteration());
}
@Override
public void preIteration(WorkerContext<MASTER_RESULT, WORKER_RESULT> context) {
context.setLastMasterResult(this.coordinator.getMasterResult());
LOG.info("Worker {} is started in iteration {}.", context.getContainerId(), context.getCurrentIteration());
}
@Override
public void postIteration(WorkerContext<MASTER_RESULT, WORKER_RESULT> context) {
this.coordinator.signalMaster(context.getCurrentIteration(), Integer.parseInt(context.getContainerId()) - 1,
context.getWorkerResult());
this.coordinator.awaitMaster(context.getCurrentIteration());
LOG.info("Worker {} is done in iteration {}.", context.getContainerId(), context.getCurrentIteration());
}
public void setCoordinator(InMemoryCoordinator<MASTER_RESULT, WORKER_RESULT> coordinator) {
this.coordinator = coordinator;
}
}