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1   /**
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  package org.apache.hadoop.hbase.procedure;
19  
20  import java.io.Closeable;
21  import java.io.IOException;
22  
23  import org.apache.hadoop.hbase.classification.InterfaceAudience;
24  import org.apache.hadoop.hbase.classification.InterfaceStability;
25  import org.apache.hadoop.hbase.errorhandling.ForeignException;
26  
27  /**
28   * This is the notification interface for Procedures that encapsulates message passing from
29   * members to a coordinator.  Each of these calls should send a message to the coordinator.
30   */
31  @InterfaceAudience.Private
32  public interface ProcedureMemberRpcs extends Closeable {
33  
34    /**
35     * Initialize and start any threads or connections the member needs.
36     */
37    void start(final String memberName, final ProcedureMember member);
38  
39    /**
40     * Each subprocedure is being executed on a member.  This is the identifier for the member.
41     * @return the member name
42     */
43    String getMemberName();
44  
45    /**
46     * Notify the coordinator that we aborted the specified {@link Subprocedure}
47     *
48     * @param sub the {@link Subprocedure} we are aborting
49     * @param cause the reason why the member's subprocedure aborted
50     * @throws IOException thrown when the rpcs can't reach the other members of the procedure (and
51     *  thus can't recover).
52     */
53    void sendMemberAborted(Subprocedure sub, ForeignException cause) throws IOException;
54  
55    /**
56     * Notify the coordinator that the specified {@link Subprocedure} has acquired the locally required
57     * barrier condition.
58     *
59     * @param sub the specified {@link Subprocedure}
60     * @throws IOException if we can't reach the coordinator
61     */
62    void sendMemberAcquired(Subprocedure sub) throws IOException;
63  
64    /**
65     * Notify the coordinator that the specified {@link Subprocedure} has completed the work that
66     * needed to be done under the global barrier.
67     *
68     * @param sub the specified {@link Subprocedure}
69     * @param data the data the member returns to the coordinator along with the notification
70     * @throws IOException if we can't reach the coordinator
71     */
72    void sendMemberCompleted(Subprocedure sub, byte[] data) throws IOException;
73  }