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.client.meta;
  
  import alluxio.Client;
  import alluxio.grpc.BackupPRequest;
  import alluxio.grpc.MasterInfo;
  import alluxio.grpc.MasterInfoField;
  import alluxio.grpc.ProxyStatus;
  import alluxio.wire.BackupStatus;
  import alluxio.wire.ConfigCheckReport;
  
  import java.io.IOException;
  import java.util.List;
  import java.util.Set;
  import java.util.UUID;
  
  /**
   * Interface for a meta master client.
   */
  public interface MetaMasterClient extends Client {
  
    /**
     * Takes a backup.
     *
     * Note: If backup request ask for async execution, it will return after initiating the backup.
     *       Status for the in-progress backup will be returned. {@link #getBackupStatus} should
     *       be called for querying the status of the on-going backup.
     *
     * Note: When leader has no standby in an HA cluster, it will reject backup. This could
     *       be allowed by passing "AllowLeader" option in the request.
     *
     * @param backupRequest the backup request
     * @return status of backup
     * @throws IOException
     */
    BackupStatus backup(BackupPRequest backupRequest) throws IOException;
  
    /**
     * Queries the status of a backup.
     *
     * @param backupId backup id
     * @return the status of the latest backup
     * @throws IOException
     */
    BackupStatus getBackupStatus(UUID backupId) throws IOException;
  
    /**
     * Gets the server-side configuration check report.
     *
     * @return configuration check report
     */
    ConfigCheckReport getConfigReport() throws IOException;
  
    /**
     * @param masterInfoFields optional list of fields to query; if null all fields will be queried
     * @return the requested master info
     */
    MasterInfo getMasterInfo(Set<MasterInfoField> masterInfoFields) throws IOException;
  
    /**
     * Creates a checkpoint in the primary master journal system.
     *
     * @return the hostname of the master that did the checkpoint
     */
    String checkpoint() throws IOException;
  
    /**
     * Lists information of all known proxy instances from the primary master.
     *
     * @return the list of proxy status
     */
    List<ProxyStatus> listProxyStatus() throws IOException;
  }
  