org.elasticsearch.search.aggregations.MultiBucketConsumerService Maven / Gradle / Ivy
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* the Apache License, Version 2.0 (the "License"); you may
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* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
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package org.elasticsearch.search.aggregations;
import org.elasticsearch.cluster.service.ClusterService;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.settings.Setting;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.aggregations.bucket.BucketsAggregator;
import java.io.IOException;
import java.util.function.IntConsumer;
/**
* An aggregation service that creates instances of {@link MultiBucketConsumer}.
* The consumer is used by {@link BucketsAggregator} and {@link InternalMultiBucketAggregation} to limit the number of buckets created
* in {@link Aggregator#buildAggregation} and {@link InternalAggregation#reduce}.
* The limit can be set by changing the `search.max_buckets` cluster setting and defaults to 10000.
*/
public class MultiBucketConsumerService {
public static final int DEFAULT_MAX_BUCKETS = 10000;
public static final Setting MAX_BUCKET_SETTING =
Setting.intSetting("search.max_buckets", DEFAULT_MAX_BUCKETS, 0, Setting.Property.NodeScope, Setting.Property.Dynamic);
private volatile int maxBucket;
public MultiBucketConsumerService(ClusterService clusterService, Settings settings) {
this.maxBucket = MAX_BUCKET_SETTING.get(settings);
clusterService.getClusterSettings().addSettingsUpdateConsumer(MAX_BUCKET_SETTING, this::setMaxBucket);
}
private void setMaxBucket(int maxBucket) {
this.maxBucket = maxBucket;
}
public static class TooManyBucketsException extends AggregationExecutionException {
private final int maxBuckets;
public TooManyBucketsException(String message, int maxBuckets) {
super(message);
this.maxBuckets = maxBuckets;
}
public TooManyBucketsException(StreamInput in) throws IOException {
super(in);
maxBuckets = in.readInt();
}
@Override
public void writeTo(StreamOutput out) throws IOException {
super.writeTo(out);
out.writeInt(maxBuckets);
}
public int getMaxBuckets() {
return maxBuckets;
}
@Override
public RestStatus status() {
return RestStatus.SERVICE_UNAVAILABLE;
}
@Override
protected void metadataToXContent(XContentBuilder builder, Params params) throws IOException {
builder.field("max_buckets", maxBuckets);
}
}
/**
* An {@link IntConsumer} that throws a {@link TooManyBucketsException}
* when the sum of the provided values is above the limit (`search.max_buckets`).
* It is used by aggregators to limit the number of bucket creation during
* {@link Aggregator#buildAggregation} and {@link InternalAggregation#reduce}.
*/
public static class MultiBucketConsumer implements IntConsumer {
private final int limit;
// aggregations execute in a single thread so no atomic here
private int count;
public MultiBucketConsumer(int limit) {
this.limit = limit;
}
@Override
public void accept(int value) {
count += value;
if (count > limit) {
throw new TooManyBucketsException("Trying to create too many buckets. Must be less than or equal to: [" + limit
+ "] but was [" + count + "]. This limit can be set by changing the [" +
MAX_BUCKET_SETTING.getKey() + "] cluster level setting.", limit);
}
}
public void reset() {
this.count = 0;
}
public int getCount() {
return count;
}
public int getLimit() {
return limit;
}
}
public MultiBucketConsumer create() {
return new MultiBucketConsumer(maxBucket);
}
}