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Elasticsearch subproject :server
/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.index.engine;
import org.apache.logging.log4j.Logger;
import org.apache.lucene.index.ConcurrentMergeScheduler;
import org.apache.lucene.index.MergePolicy;
import org.apache.lucene.index.MergeScheduler;
import org.elasticsearch.common.logging.Loggers;
import org.elasticsearch.common.metrics.CounterMetric;
import org.elasticsearch.common.metrics.MeanMetric;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.unit.ByteSizeValue;
import org.elasticsearch.common.util.concurrent.ConcurrentCollections;
import org.elasticsearch.common.util.concurrent.EsExecutors;
import org.elasticsearch.core.TimeValue;
import org.elasticsearch.index.IndexSettings;
import org.elasticsearch.index.MergeSchedulerConfig;
import org.elasticsearch.index.merge.MergeStats;
import org.elasticsearch.index.merge.OnGoingMerge;
import org.elasticsearch.index.shard.ShardId;
import java.io.IOException;
import java.util.Collections;
import java.util.Locale;
import java.util.Set;
/**
* An extension to the {@link ConcurrentMergeScheduler} that provides tracking on merge times, total
* and current merges.
*/
class ElasticsearchConcurrentMergeScheduler extends ConcurrentMergeScheduler {
protected final Logger logger;
private final Settings indexSettings;
private final ShardId shardId;
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 CounterMetric totalMergeStoppedTime = new CounterMetric();
private final CounterMetric totalMergeThrottledTime = new CounterMetric();
private final Set onGoingMerges = ConcurrentCollections.newConcurrentSet();
private final Set readOnlyOnGoingMerges = Collections.unmodifiableSet(onGoingMerges);
private final MergeSchedulerConfig config;
ElasticsearchConcurrentMergeScheduler(ShardId shardId, IndexSettings indexSettings) {
this.config = indexSettings.getMergeSchedulerConfig();
this.shardId = shardId;
this.indexSettings = indexSettings.getSettings();
this.logger = Loggers.getLogger(getClass(), shardId);
refreshConfig();
}
public Set onGoingMerges() {
return readOnlyOnGoingMerges;
}
/** We're currently only interested in messages with this prefix. */
private static final String MERGE_THREAD_MESSAGE_PREFIX = "merge thread";
@Override
/** Overridden to route specific MergeThread messages to our logger. */
protected boolean verbose() {
if (logger.isTraceEnabled() && Thread.currentThread() instanceof MergeThread) {
return true;
}
return super.verbose();
}
@Override
/** Overridden to route specific MergeThread messages to our logger. */
protected void message(String message) {
if (logger.isTraceEnabled() && Thread.currentThread() instanceof MergeThread && message.startsWith(MERGE_THREAD_MESSAGE_PREFIX)) {
logger.trace("{}", message);
}
super.message(message);
}
private static String getSegmentName(MergePolicy.OneMerge merge) {
return merge.getMergeInfo() != null ? merge.getMergeInfo().info.name : "_na_";
}
@Override
protected void doMerge(MergeSource mergeSource, MergePolicy.OneMerge merge) throws IOException {
int totalNumDocs = merge.totalNumDocs();
long totalSizeInBytes = merge.totalBytesSize();
long timeNS = System.nanoTime();
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",
getSegmentName(merge),
merge.segments.size(),
totalNumDocs,
new ByteSizeValue(totalSizeInBytes),
new ByteSizeValue(merge.estimatedMergeBytes)
);
}
try {
beforeMerge(onGoingMerge);
super.doMerge(mergeSource, merge);
} finally {
long tookMS = TimeValue.nsecToMSec(System.nanoTime() - timeNS);
onGoingMerges.remove(onGoingMerge);
afterMerge(onGoingMerge);
currentMerges.dec();
currentMergesNumDocs.dec(totalNumDocs);
currentMergesSizeInBytes.dec(totalSizeInBytes);
totalMergesNumDocs.inc(totalNumDocs);
totalMergesSizeInBytes.inc(totalSizeInBytes);
totalMerges.inc(tookMS);
long stoppedMS = TimeValue.nsecToMSec(
merge.getMergeProgress().getPauseTimes().get(MergePolicy.OneMergeProgress.PauseReason.STOPPED)
);
long throttledMS = TimeValue.nsecToMSec(
merge.getMergeProgress().getPauseTimes().get(MergePolicy.OneMergeProgress.PauseReason.PAUSED)
);
totalMergeStoppedTime.inc(stoppedMS);
totalMergeThrottledTime.inc(throttledMS);
String message = String.format(
Locale.ROOT,
"merge segment [%s] done: took [%s], [%,.1f MB], [%,d docs], [%s stopped], [%s throttled]",
getSegmentName(merge),
TimeValue.timeValueMillis(tookMS),
totalSizeInBytes / 1024f / 1024f,
totalNumDocs,
TimeValue.timeValueMillis(stoppedMS),
TimeValue.timeValueMillis(throttledMS)
);
if (tookMS > 20000) { // if more than 20 seconds, DEBUG log it
logger.debug("{}", message);
} else if (logger.isTraceEnabled()) {
logger.trace("{}", message);
}
}
}
/**
* 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;
}
@Override
protected boolean maybeStall(MergeSource mergeSource) {
// Don't stall here, because we do our own index throttling (in InternalEngine.IndexThrottle) when merges can't keep up
return true;
}
@Override
protected MergeThread getMergeThread(MergeSource mergeSource, MergePolicy.OneMerge merge) throws IOException {
MergeThread thread = super.getMergeThread(mergeSource, merge);
thread.setName(
EsExecutors.threadName(indexSettings, "[" + shardId.getIndexName() + "][" + shardId.id() + "]: " + thread.getName())
);
return thread;
}
MergeStats stats() {
final MergeStats mergeStats = new MergeStats();
mergeStats.add(
totalMerges.count(),
totalMerges.sum(),
totalMergesNumDocs.count(),
totalMergesSizeInBytes.count(),
currentMerges.count(),
currentMergesNumDocs.count(),
currentMergesSizeInBytes.count(),
totalMergeStoppedTime.count(),
totalMergeThrottledTime.count(),
config.isAutoThrottle() ? getIORateLimitMBPerSec() : Double.POSITIVE_INFINITY
);
return mergeStats;
}
void refreshConfig() {
if (this.getMaxMergeCount() != config.getMaxMergeCount() || this.getMaxThreadCount() != config.getMaxThreadCount()) {
this.setMaxMergesAndThreads(config.getMaxMergeCount(), config.getMaxThreadCount());
}
boolean isEnabled = getIORateLimitMBPerSec() != Double.POSITIVE_INFINITY;
if (config.isAutoThrottle() && isEnabled == false) {
enableAutoIOThrottle();
} else if (config.isAutoThrottle() == false && isEnabled) {
disableAutoIOThrottle();
}
}
}