DefaultLoadBalancingService.java

/*
 * Copyright 2014-2016 CyberVision, 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 org.kaaproject.kaa.server.operations.service.loadbalance;

import org.kaaproject.kaa.server.common.zk.gen.LoadInfo;
import org.kaaproject.kaa.server.common.zk.gen.OperationsNodeInfo;
import org.kaaproject.kaa.server.common.zk.operations.OperationsNode;
import org.kaaproject.kaa.server.operations.service.akka.AkkaService;
import org.kaaproject.kaa.server.operations.service.akka.AkkaServiceStatus;
import org.kaaproject.kaa.server.operations.service.akka.AkkaStatusListener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

import java.lang.management.ManagementFactory;
import java.lang.management.OperatingSystemMXBean;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

@Service
public class DefaultLoadBalancingService implements LoadBalancingService {

  private static final long DEFAULT_STATS_UPDATE_FREQUENCY = 10 * 1000;

  /**
   * The Constant LOG.
   */
  private static final Logger LOG = LoggerFactory.getLogger(DefaultLoadBalancingService.class);

  /**
   * The delta service.
   */
  @Autowired
  private AkkaService akkaService;

  @Value("#{properties[load_stats_update_frequency]}")
  private long loadStatsUpdateFrequency = DEFAULT_STATS_UPDATE_FREQUENCY;

  private ExecutorService pool = Executors.newSingleThreadExecutor();

  private OperationsNode operationsNode;

  @Override
  public void start(OperationsNode operationsNode) {
    LOG.info("Starting service using {} update frequency", loadStatsUpdateFrequency);
    this.operationsNode = operationsNode;
    akkaService.setStatusListener(new AkkaStatusListener() {

      @Override
      public void onStatusUpdate(final AkkaServiceStatus status) {
        pool.submit(new Runnable() {

          @Override
          public void run() {
            DefaultLoadBalancingService.this.onStatusUpdate(status);
          }
        });
      }
    }, loadStatsUpdateFrequency);
  }

  @Override
  public void stop() {
    LOG.info("Stopping service");
    akkaService.removeStatusListener();
    pool.shutdown();
    try {
      pool.awaitTermination(3, TimeUnit.SECONDS);
    } catch (InterruptedException ex) {
      LOG.error("Failed to terminate service", ex);
    }
  }

  @Override
  public void onStatusUpdate(AkkaServiceStatus status) {
    try {
      OperationsNodeInfo nodeInfo = operationsNode.getNodeInfo();
      OperatingSystemMXBean operatingSystemMxBean = ManagementFactory.getOperatingSystemMXBean();
      nodeInfo.setLoadInfo(new LoadInfo(
          status.getEndpointCount(), operatingSystemMxBean.getSystemLoadAverage()));
      operationsNode.updateNodeData(nodeInfo);
      LOG.info("Updated load info: {}", nodeInfo.getLoadInfo());
    } catch (Exception ex) {
      LOG.error("Failed to report status update to control service", ex);
    }
  }
}