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.cli.fsadmin.journal;
  
  import alluxio.cli.CommandUtils;
  import alluxio.cli.fsadmin.command.AbstractFsAdminCommand;
  import alluxio.cli.fsadmin.command.Context;
  import alluxio.conf.AlluxioConfiguration;
  import alluxio.exception.status.InvalidArgumentException;
  import alluxio.util.CommonUtils;
  
  import org.apache.commons.cli.CommandLine;
  
  import java.io.IOException;
  
  /**
   * Command for triggering a checkpoint in the primary master journal system.
   */
  public class CheckpointCommand extends AbstractFsAdminCommand {
  
    /**
     * @param context fsadmin command context
     * @param alluxioConf Alluxio configuration
     */
    public CheckpointCommand(Context context, AlluxioConfiguration alluxioConf) {
      super(context);
    }
  
    @Override
    public String getCommandName() {
      return "checkpoint";
    }
  
    @Override
    public int run(CommandLine cl) throws IOException {
      Thread thread = CommonUtils.createProgressThread(System.out);
      thread.start();
      try {
        String masterHostname = mMetaClient.checkpoint();
        mPrintStream.printf("Successfully took a checkpoint on master %s%n", masterHostname);
      } finally {
        thread.interrupt();
      }
      return 0;
    }
  
    @Override
    public String getUsage() {
      return "checkpoint";
    }
  
    @Override
    public String getDescription() {
      return "creates a checkpoint in the primary master journal system. This command "
          + "is mainly used for debugging and to avoid master journal logs "
          + "from growing unbounded. Checkpointing requires a pause in master metadata changes, "
          + "so use this command sparingly to avoid interfering with other users of the system.";
    }
  
    @Override
    public void validateArgs(CommandLine cl) throws InvalidArgumentException {
      CommandUtils.checkNumOfArgsEquals(this, cl, 0);
    }
  }
  