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1   /*
2    *
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *     http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing, software
14   * distributed under the License is distributed on an "AS IS" BASIS,
15   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16   * See the License for the specific language governing permissions and
17   * limitations under the License.
18   */
19  package org.apache.hadoop.hbase.replication;
20  
21  import java.util.List;
22  
23  import org.apache.hadoop.hbase.classification.InterfaceAudience;
24  import org.apache.zookeeper.KeeperException;
25  
26  /**
27   * This provides an interface for clients of replication to view replication queues. These queues
28   * keep track of the sources(WALs/HFile references) that still need to be replicated to remote
29   * clusters.
30   */
31  @InterfaceAudience.Private
32  public interface ReplicationQueuesClient {
33  
34    /**
35     * Initialize the replication queue client interface.
36     */
37    public void init() throws ReplicationException;
38  
39    /**
40     * Get a list of all region servers that have outstanding replication queues. These servers could
41     * be alive, dead or from a previous run of the cluster.
42     * @return a list of server names
43     * @throws KeeperException zookeeper exception
44     */
45    List<String> getListOfReplicators() throws KeeperException;
46  
47    /**
48     * Get a list of all WALs in the given queue on the given region server.
49     * @param serverName the server name of the region server that owns the queue
50     * @param queueId a String that identifies the queue
51     * @return a list of WALs, null if this region server is dead and has no outstanding queues
52     * @throws KeeperException zookeeper exception
53     */
54    List<String> getLogsInQueue(String serverName, String queueId) throws KeeperException;
55  
56    /**
57     * Get a list of all queues for the specified region server.
58     * @param serverName the server name of the region server that owns the set of queues
59     * @return a list of queueIds, null if this region server is not a replicator.
60     */
61    List<String> getAllQueues(String serverName) throws KeeperException;
62  
63    /**
64     * Get the cversion of replication rs node. This can be used as optimistic locking to get a
65     * consistent snapshot of the replication queues.
66     * @return cversion of replication rs node
67     */
68    int getQueuesZNodeCversion() throws KeeperException;
69  
70    /**
71     * Get the change version number of replication hfile references node. This can be used as
72     * optimistic locking to get a consistent snapshot of the replication queues of hfile references.
73     * @return change version number of hfile references node
74     */
75    int getHFileRefsNodeChangeVersion() throws KeeperException;
76  
77    /**
78     * Get list of all peers from hfile reference queue.
79     * @return a list of peer ids
80     * @throws KeeperException zookeeper exception
81     */
82    List<String> getAllPeersFromHFileRefsQueue() throws KeeperException;
83  
84    /**
85     * Get a list of all hfile references in the given peer.
86     * @param peerId a String that identifies the peer
87     * @return a list of hfile references, null if not found any
88     * @throws KeeperException zookeeper exception
89     */
90    List<String> getReplicableHFiles(String peerId) throws KeeperException;
91  }