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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  
19  package org.apache.hadoop.hbase.regionserver.wal;
20  
21  import org.apache.hadoop.hbase.metrics.BaseSource;
22  
23  /**
24   * Interface of the source that will export metrics about the region server's WAL.
25   */
26  public interface MetricsWALSource extends BaseSource {
27  
28  
29    /**
30     * The name of the metrics
31     */
32    String METRICS_NAME = "WAL";
33  
34    /**
35     * The name of the metrics context that metrics will be under.
36     */
37    String METRICS_CONTEXT = "regionserver";
38  
39    /**
40     * Description
41     */
42    String METRICS_DESCRIPTION = "Metrics about HBase RegionServer WAL";
43  
44    /**
45     * The name of the metrics context that metrics will be under in jmx
46     */
47    String METRICS_JMX_CONTEXT = "RegionServer,sub=" + METRICS_NAME;
48  
49  
50    String APPEND_TIME = "appendTime";
51    String APPEND_TIME_DESC = "Time an append to the log took.";
52    String APPEND_COUNT = "appendCount";
53    String APPEND_COUNT_DESC = "Number of appends to the write ahead log.";
54    String APPEND_SIZE = "appendSize";
55    String APPEND_SIZE_DESC = "Size (in bytes) of the data appended to the WAL.";
56    String SLOW_APPEND_COUNT = "slowAppendCount";
57    String SLOW_APPEND_COUNT_DESC = "Number of appends that were slow.";
58    String SYNC_TIME = "syncTime";
59    String SYNC_TIME_DESC = "The time it took to sync the WAL to HDFS.";
60    String ROLL_REQUESTED = "rollRequest";
61    String ROLL_REQUESTED_DESC = "How many times a log roll has been requested total";
62    String LOW_REPLICA_ROLL_REQUESTED = "lowReplicaRollRequest";
63    String LOW_REPLICA_ROLL_REQUESTED_DESC =
64        "How many times a log roll was requested due to too few DN's in the write pipeline.";
65  
66    /**
67     * Add the append size.
68     */
69    void incrementAppendSize(long size);
70  
71    /**
72     * Add the time it took to append.
73     */
74    void incrementAppendTime(long time);
75  
76    /**
77     * Increment the count of wal appends
78     */
79    void incrementAppendCount();
80  
81    /**
82     * Increment the number of appends that were slow
83     */
84    void incrementSlowAppendCount();
85  
86    /**
87     * Add the time it took to sync the wal.
88     */
89    void incrementSyncTime(long time);
90  
91    void incrementLogRollRequested();
92  
93    void incrementLowReplicationLogRoll();
94  
95  }