content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.worker;
  
  import alluxio.HealthCheckClient;
  import alluxio.RuntimeConstants;
  import alluxio.conf.AlluxioConfiguration;
  import alluxio.conf.Configuration;
  import alluxio.retry.ExponentialBackoffRetry;
  import alluxio.retry.RetryPolicy;
  import alluxio.util.network.NetworkAddressUtils;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.function.Supplier;
  
  /**
   * Alluxio worker monitor for inquiring AlluxioWorker service availability.
   */
  public final class AlluxioWorkerMonitor {
    private static final Logger LOG = LoggerFactory.getLogger(AlluxioWorkerMonitor.class);
  
    public static final Supplier<RetryPolicy> ONE_MIN_EXP_BACKOFF =
        () -> new ExponentialBackoffRetry(50, 500, 120);
  
    /**
     * Starts the Alluxio worker monitor.
     *
     * @param args command line arguments, should be empty
     */
    public static void main(String[] args) {
      if (args.length != 0) {
        LOG.info("java -cp {} {}", RuntimeConstants.ALLUXIO_JAR,
            AlluxioWorkerMonitor.class.getCanonicalName());
        LOG.warn("ignoring arguments");
      }
      AlluxioConfiguration conf = Configuration.global();
  
      HealthCheckClient client = new WorkerHealthCheckClient(
          NetworkAddressUtils.getConnectAddress(NetworkAddressUtils.ServiceType.WORKER_RPC, conf),
          ONE_MIN_EXP_BACKOFF, conf);
      if (!client.isServing()) {
        System.exit(1);
      }
      System.exit(0);
    }
  
    private AlluxioWorkerMonitor() {} // prevent instantiation
  }
  