DistributedSchedulerService.java

/*
 * Copyright © 2014 Cask Data, Inc.
 *
 * 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 co.cask.cdap.internal.app.runtime.schedule;

import co.cask.cdap.app.store.Store;
import co.cask.cdap.common.service.RetryOnStartFailureService;
import co.cask.cdap.common.service.RetryStrategies;
import com.google.common.base.Supplier;
import com.google.common.util.concurrent.AbstractService;
import com.google.common.util.concurrent.Service;
import com.google.inject.Inject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.TimeUnit;

/**
 * Scheduler service to run in Distributed CDAP. Waits for Dataset service to be available.
 */
public final class DistributedSchedulerService extends AbstractSchedulerService {

  private static final Logger LOG = LoggerFactory.getLogger(DistributedSchedulerService.class);
  private final Service serviceDelegate;

  @Inject
  public DistributedSchedulerService(TimeScheduler timeScheduler, StreamSizeScheduler streamSizeScheduler,
                                     Store store) {
    super(timeScheduler, streamSizeScheduler, store);
    this.serviceDelegate = new RetryOnStartFailureService(new Supplier<Service>() {
      @Override
      public Service get() {
        return new AbstractService() {
          @Override
          protected void doStart() {
            try {
              startSchedulers();
              notifyStarted();
            } catch (SchedulerException e) {
              notifyFailed(e);
            }
          }

          @Override
          protected void doStop() {
            try {
              stopScheduler();
              notifyStopped();
            } catch (SchedulerException e) {
              notifyFailed(e);
            }
          }
        };
      }
    }, RetryStrategies.exponentialDelay(200, 5000, TimeUnit.MILLISECONDS));
  }

  @Override
  protected void startUp() throws Exception {
    LOG.info("Starting scheduler.");
    serviceDelegate.startAndWait();
  }

  @Override
  protected void shutDown() throws Exception {
    LOG.info("Stopping scheduler.");
    serviceDelegate.stopAndWait();
  }
}