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.master.journal;
  
  import alluxio.grpc.GetNodeStatePResponse;
  import alluxio.grpc.GetQuorumInfoPResponse;
  import alluxio.grpc.GetTransferLeaderMessagePResponse;
  import alluxio.grpc.NetAddress;
  import alluxio.master.Master;
  
  import java.io.IOException;
  
  /**
   * Interface for journal master implementations.
   */
  public interface JournalMaster extends Master {
    /**
     * Quorum information for participating servers in journal. This method is supported only for
     * {@link alluxio.master.journal.JournalType#EMBEDDED} journal.
     *
     * @return the quorum info
     * @throws IOException if error occurs while performing the operation
     */
    GetQuorumInfoPResponse getQuorumInfo() throws IOException;
  
    /**
     * Removes a server from journal quorum. This method is supported only for
     * {@link alluxio.master.journal.JournalType#EMBEDDED} journal.
     *
     * @param serverAddress server address to remove from quorum
     * @throws IOException if error occurs while performing the operation
     */
    void removeQuorumServer(NetAddress serverAddress) throws IOException;
  
    /**
     * Changes the leading master of the journal quorum. This method is supported only for
     * {@link alluxio.master.journal.JournalType#EMBEDDED} journal.
     *
     * @param newLeaderAddress server address to remove from quorum
     * @return the guid of transfer leader command
     */
    String transferLeadership(NetAddress newLeaderAddress);
  
    /**
     * Resets RaftPeer priorities.
     *
     * @throws IOException if error occurs while performing the operation
     */
    void resetPriorities() throws IOException;
  
    /**
     * Gets exception messages thrown when transferring the leader.
     * @param transferId the guid of transferLeader command
     * @return exception message
     */
    GetTransferLeaderMessagePResponse getTransferLeaderMessage(String transferId);
  
    /**
     * Gets the node state. This endpoint is available for both UFS and embedded journals.
     * If HA mode is turn off, the node state will always be returned as PRIMARY.
     * @return whether the node is a primary or standby
     */
    GetNodeStatePResponse getNodeState();
  }
  