summaryrefslogtreecommitdiff
path: root/src/main/java/org/apache/lucene/index/TrackingConcurrentMergeScheduler.java
blob: 66b3328898275cd4cea842fe7a424723042cf673 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.lucene.index;

import org.elasticsearch.common.logging.ESLogger;
import org.elasticsearch.common.metrics.CounterMetric;
import org.elasticsearch.common.metrics.MeanMetric;
import org.elasticsearch.common.unit.ByteSizeValue;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.common.util.concurrent.ConcurrentCollections;
import org.elasticsearch.index.merge.OnGoingMerge;

import java.io.IOException;
import java.util.Collections;
import java.util.Set;

/**
 * An extension to the {@link ConcurrentMergeScheduler} that provides tracking on merge times, total
 * and current merges.
 */
public class TrackingConcurrentMergeScheduler extends ConcurrentMergeScheduler {

    protected final ESLogger logger;

    private final MeanMetric totalMerges = new MeanMetric();
    private final CounterMetric totalMergesNumDocs = new CounterMetric();
    private final CounterMetric totalMergesSizeInBytes = new CounterMetric();
    private final CounterMetric currentMerges = new CounterMetric();
    private final CounterMetric currentMergesNumDocs = new CounterMetric();
    private final CounterMetric currentMergesSizeInBytes = new CounterMetric();

    private final Set<OnGoingMerge> onGoingMerges = ConcurrentCollections.newConcurrentSet();
    private final Set<OnGoingMerge> readOnlyOnGoingMerges = Collections.unmodifiableSet(onGoingMerges);

    public TrackingConcurrentMergeScheduler(ESLogger logger) {
        super();
        this.logger = logger;
    }

    public long totalMerges() {
        return totalMerges.count();
    }

    public long totalMergeTime() {
        return totalMerges.sum();
    }

    public long totalMergeNumDocs() {
        return totalMergesNumDocs.count();
    }

    public long totalMergeSizeInBytes() {
        return totalMergesSizeInBytes.count();
    }

    public long currentMerges() {
        return currentMerges.count();
    }

    public long currentMergesNumDocs() {
        return currentMergesNumDocs.count();
    }

    public long currentMergesSizeInBytes() {
        return currentMergesSizeInBytes.count();
    }

    public Set<OnGoingMerge> onGoingMerges() {
        return readOnlyOnGoingMerges;
    }

    @Override
    protected void doMerge(MergePolicy.OneMerge merge) throws IOException {
        int totalNumDocs = merge.totalNumDocs();
        // don't used #totalBytesSize() since need to be executed under IW lock, might be fixed in future Lucene version
        long totalSizeInBytes = merge.estimatedMergeBytes;
        long time = System.currentTimeMillis();
        currentMerges.inc();
        currentMergesNumDocs.inc(totalNumDocs);
        currentMergesSizeInBytes.inc(totalSizeInBytes);

        OnGoingMerge onGoingMerge = new OnGoingMerge(merge);
        onGoingMerges.add(onGoingMerge);

        if (logger.isTraceEnabled()) {
            logger.trace("merge [{}] starting..., merging [{}] segments, [{}] docs, [{}] size, into [{}] estimated_size", merge.info == null ? "_na_" : merge.info.info.name, merge.segments.size(), totalNumDocs, new ByteSizeValue(totalSizeInBytes), new ByteSizeValue(merge.estimatedMergeBytes));
        }
        try {
            beforeMerge(onGoingMerge);
            super.doMerge(merge);
        } finally {
            long took = System.currentTimeMillis() - time;

            onGoingMerges.remove(onGoingMerge);
            afterMerge(onGoingMerge);

            currentMerges.dec();
            currentMergesNumDocs.dec(totalNumDocs);
            currentMergesSizeInBytes.dec(totalSizeInBytes);

            totalMergesNumDocs.inc(totalNumDocs);
            totalMergesSizeInBytes.inc(totalSizeInBytes);
            totalMerges.inc(took);
            if (took > 20000) { // if more than 20 seconds, DEBUG log it
                logger.debug("merge [{}] done, took [{}]", merge.info == null ? "_na_" : merge.info.info.name, TimeValue.timeValueMillis(took));
            } else if (logger.isTraceEnabled()) {
                logger.trace("merge [{}] done, took [{}]", merge.info == null ? "_na_" : merge.info.info.name, TimeValue.timeValueMillis(took));
            }
        }
    }

    /**
     * A callback allowing for custom logic before an actual merge starts.
     */
    protected void beforeMerge(OnGoingMerge merge) {

    }

    /**
     * A callback allowing for custom logic before an actual merge starts.
     */
    protected void afterMerge(OnGoingMerge merge) {

    }

    @Override
    public MergeScheduler clone() {
        // Lucene IW makes a clone internally but since we hold on to this instance 
        // the clone will just be the identity.
        return this;
    }
}