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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.SortedMap;
23  import java.util.SortedSet;
24  
25  import org.apache.hadoop.hbase.classification.InterfaceAudience;
26  
27  /**
28   * This provides an interface for maintaining a region server's replication queues. These queues
29   * keep track of the WALs and HFile references (if hbase.replication.bulkload.enabled is enabled)
30   * that still need to be replicated to remote clusters.
31   */
32  @InterfaceAudience.Private
33  public interface ReplicationQueues {
34  
35    /**
36     * Initialize the region server replication queue interface.
37     * @param serverName The server name of the region server that owns the replication queues this
38     *          interface manages.
39     */
40    void init(String serverName) throws ReplicationException;
41  
42    /**
43     * Remove a replication queue.
44     * @param queueId a String that identifies the queue.
45     */
46    void removeQueue(String queueId);
47  
48    /**
49     * Add a new WAL file to the given queue. If the queue does not exist it is created.
50     * @param queueId a String that identifies the queue.
51     * @param filename name of the WAL
52     */
53    void addLog(String queueId, String filename) throws ReplicationException;
54  
55    /**
56     * Remove an WAL file from the given queue.
57     * @param queueId a String that identifies the queue.
58     * @param filename name of the WAL
59     */
60    void removeLog(String queueId, String filename);
61  
62    /**
63     * Set the current position for a specific WAL in a given queue.
64     * @param queueId a String that identifies the queue
65     * @param filename name of the WAL
66     * @param position the current position in the file
67     */
68    void setLogPosition(String queueId, String filename, long position);
69  
70    /**
71     * Get the current position for a specific WAL in a given queue.
72     * @param queueId a String that identifies the queue
73     * @param filename name of the WAL
74     * @return the current position in the file
75     */
76    long getLogPosition(String queueId, String filename) throws ReplicationException;
77  
78    /**
79     * Remove all replication queues for this region server.
80     */
81    void removeAllQueues();
82  
83    /**
84     * Get a list of all WALs in the given queue.
85     * @param queueId a String that identifies the queue
86     * @return a list of WALs, null if this region server is dead and has no outstanding queues
87     */
88    List<String> getLogsInQueue(String queueId);
89  
90    /**
91     * Get a list of all queues for this region server.
92     * @return a list of queueIds, null if this region server is dead and has no outstanding queues
93     */
94    List<String> getAllQueues();
95  
96    /**
97     * Take ownership for the set of queues belonging to a dead region server.
98     * @param regionserver the id of the dead region server
99     * @return A SortedMap of the queues that have been claimed, including a SortedSet of WALs in
100    *         each queue. Returns an empty map if no queues were failed-over.
101    */
102   SortedMap<String, SortedSet<String>> claimQueues(String regionserver);
103 
104   /**
105    * Get a list of all region servers that have outstanding replication queues. These servers could
106    * be alive, dead or from a previous run of the cluster.
107    * @return a list of server names
108    */
109   List<String> getListOfReplicators();
110 
111   /**
112    * Checks if the provided znode is the same as this region server's
113    * @param znode to check
114    * @return if this is this rs's znode
115    */
116   boolean isThisOurZnode(String znode);
117 
118   /**
119    * Add a peer to hfile reference queue if peer does not exist.
120    * @param peerId peer cluster id to be added
121    * @throws ReplicationException if fails to add a peer id to hfile reference queue
122    */
123   void addPeerToHFileRefs(String peerId) throws ReplicationException;
124 
125   /**
126    * Add new hfile references to the queue.
127    * @param peerId peer cluster id to which the hfiles need to be replicated
128    * @param files list of hfile references to be added
129    * @throws ReplicationException if fails to add a hfile reference
130    */
131   void addHFileRefs(String peerId, List<String> files) throws ReplicationException;
132 
133   /**
134    * Remove hfile references from the queue.
135    * @param peerId peer cluster id from which this hfile references needs to be removed
136    * @param files list of hfile references to be removed
137    */
138   void removeHFileRefs(String peerId, List<String> files);
139 }