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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  import java.util.Map;
23  
24  import org.apache.hadoop.hbase.classification.InterfaceAudience;
25  import org.apache.zookeeper.KeeperException;
26  
27  /**
28   * This provides an interface for clients of replication to view replication queues. These queues
29   * keep track of the sources(WALs/HFile references) that still need to be replicated to remote
30   * clusters.
31   */
32  @InterfaceAudience.Private
33  public interface ReplicationQueuesClient {
34  
35    /**
36     * Initialize the replication queue client interface.
37     */
38    public void init() throws ReplicationException;
39  
40    /**
41     * Get a list of all region servers that have outstanding replication queues. These servers could
42     * be alive, dead or from a previous run of the cluster.
43     * @return a list of server names
44     * @throws KeeperException zookeeper exception
45     */
46    List<String> getListOfReplicators() throws KeeperException;
47  
48    /**
49     * Get a list of all WALs in the given queue on the given region server.
50     * @param serverName the server name of the region server that owns the queue
51     * @param queueId a String that identifies the queue
52     * @return a list of WALs, null if this region server is dead and has no outstanding queues
53     * @throws KeeperException zookeeper exception
54     */
55    List<String> getLogsInQueue(String serverName, String queueId) throws KeeperException;
56  
57    /**
58     * Get a list of all queues for the specified region server.
59     * @param serverName the server name of the region server that owns the set of queues
60     * @return a list of queueIds, null if this region server is not a replicator.
61     */
62    List<String> getAllQueues(String serverName) throws KeeperException;
63  
64    /**
65     * Get the cversion of replication rs node. This can be used as optimistic locking to get a
66     * consistent snapshot of the replication queues.
67     * @return cversion of replication rs node
68     */
69    int getQueuesZNodeCversion() throws KeeperException;
70  
71    /**
72     * Get a map of cversion of all replicator nodes. This can be used as optimistic locking
73     * to get a consistent snapshot of the replication queues.
74     * @return a map of replicator to cversion
75     */
76    Map<String, Integer> getReplicatorsZNodeCversion() throws KeeperException;
77  
78    /**
79     * Get the change version number of replication hfile references node. This can be used as
80     * optimistic locking to get a consistent snapshot of the replication queues of hfile references.
81     * @return change version number of hfile references node
82     */
83    int getHFileRefsNodeChangeVersion() throws KeeperException;
84  
85    /**
86     * Get list of all peers from hfile reference queue.
87     * @return a list of peer ids
88     * @throws KeeperException zookeeper exception
89     */
90    List<String> getAllPeersFromHFileRefsQueue() throws KeeperException;
91  
92    /**
93     * Get a list of all hfile references in the given peer.
94     * @param peerId a String that identifies the peer
95     * @return a list of hfile references, null if not found any
96     * @throws KeeperException zookeeper exception
97     */
98    List<String> getReplicableHFiles(String peerId) throws KeeperException;
99  }