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.coordination;
20 import java.io.IOException;
21 import java.util.concurrent.atomic.AtomicLong;
22
23 import org.apache.hadoop.conf.Configuration;
24 import org.apache.hadoop.fs.FileSystem;
25 import org.apache.hadoop.fs.Path;
26 import org.apache.hadoop.hbase.SplitLogTask;
27 import org.apache.hadoop.hbase.classification.InterfaceAudience;
28 import org.apache.hadoop.hbase.protobuf.generated.ClusterStatusProtos.RegionStoreSequenceIds;
29 import org.apache.hadoop.hbase.regionserver.RegionServerServices;
30 import org.apache.hadoop.hbase.regionserver.SplitLogWorker;
31 import org.apache.hadoop.hbase.regionserver.SplitLogWorker.TaskExecutor;
32
33 import com.google.common.annotations.VisibleForTesting;
34
35 /**
36 * Coordinated operations for {@link SplitLogWorker} and
37 * {@link org.apache.hadoop.hbase.regionserver.handler.WALSplitterHandler} Important
38 * methods for SplitLogWorker: <BR>
39 * {@link #isReady()} called from {@link SplitLogWorker#run()} to check whether the coordination is
40 * ready to supply the tasks <BR>
41 * {@link #taskLoop()} loop for new tasks until the worker is stopped <BR>
42 * {@link #isStop()} a flag indicates whether worker should finish <BR>
43 * {@link #registerListener()} called from {@link SplitLogWorker#run()} and could register listener
44 * for external changes in coordination (if required) <BR>
45 * {@link #endTask(SplitLogTask, AtomicLong, SplitTaskDetails)} notify coordination engine that
46 * <p>
47 * Important methods for WALSplitterHandler: <BR>
48 * splitting task has completed.
49 */
50 @InterfaceAudience.Private
51 public interface SplitLogWorkerCoordination {
52
53 /* SplitLogWorker part */
54 public static final int DEFAULT_MAX_SPLITTERS = 2;
55
56 /**
57 * Initialize internal values. This method should be used when corresponding SplitLogWorker
58 * instance is created
59 * @param server instance of RegionServerServices to work with
60 * @param conf is current configuration.
61 * @param splitTaskExecutor split executor from SplitLogWorker
62 * @param worker instance of SplitLogWorker
63 */
64 void init(RegionServerServices server, Configuration conf,
65 TaskExecutor splitTaskExecutor, SplitLogWorker worker);
66
67 /**
68 * called when Coordination should stop processing tasks and exit
69 */
70 void stopProcessingTasks();
71
72 /**
73 * @return the current value of exitWorker
74 */
75 boolean isStop();
76
77 /**
78 * Wait for the new tasks and grab one
79 * @throws InterruptedException if the SplitLogWorker was stopped
80 */
81 void taskLoop() throws InterruptedException;
82
83 /**
84 * marks log file as corrupted
85 * @param rootDir where to find the log
86 * @param name of the log
87 * @param fs file system
88 */
89 void markCorrupted(Path rootDir, String name, FileSystem fs);
90
91 /**
92 * Check whether the log splitter is ready to supply tasks
93 * @return false if there is no tasks
94 * @throws InterruptedException if the SplitLogWorker was stopped
95 */
96 boolean isReady() throws InterruptedException;
97
98 /**
99 * Used by unit tests to check how many tasks were processed
100 * @return number of tasks
101 */
102 @VisibleForTesting
103 int getTaskReadySeq();
104
105 /**
106 * set the listener for task changes. Implementation specific
107 */
108 void registerListener();
109
110 /**
111 * remove the listener for task changes. Implementation specific
112 */
113 void removeListener();
114
115 /* WALSplitterHandler part */
116
117 /**
118 * Notify coordination engine that splitting task has completed.
119 * @param slt See {@link SplitLogTask}
120 * @param ctr counter to be updated
121 * @param splitTaskDetails details about log split task (specific to coordination engine being
122 * used).
123 */
124 void endTask(SplitLogTask slt, AtomicLong ctr, SplitTaskDetails splitTaskDetails);
125
126 /**
127 * Interface for log-split tasks Used to carry implementation details in encapsulated way through
128 * Handlers to the coordination API.
129 */
130 static interface SplitTaskDetails {
131
132 /**
133 * @return full file path in HDFS for the WAL file to be split.
134 */
135 String getWALFile();
136 }
137
138 RegionStoreSequenceIds getRegionFlushedSequenceId(String failedServerName, String key)
139 throws IOException;
140
141 }