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hystrix-core developed by Netflix
/**
* Copyright 2015 Netflix, Inc.
*
* Licensed 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 com.netflix.hystrix.metric.consumer;
import com.netflix.hystrix.HystrixEventType;
import com.netflix.hystrix.HystrixThreadPoolKey;
import com.netflix.hystrix.HystrixThreadPoolMetrics;
import com.netflix.hystrix.HystrixThreadPoolProperties;
import com.netflix.hystrix.metric.HystrixCommandCompletion;
import com.netflix.hystrix.metric.HystrixThreadPoolCompletionStream;
import rx.functions.Func2;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
/**
* Maintains a stream of event counters for a given ThreadPool.
* There is a rolling window abstraction on this stream.
* The event counters object is calculated over a window of t1 milliseconds. This window has b buckets.
* Therefore, a new set of counters is produced every t2 (=t1/b) milliseconds
* t1 = {@link HystrixThreadPoolProperties#metricsRollingStatisticalWindowInMilliseconds()}
* b = {@link HystrixThreadPoolProperties#metricsRollingStatisticalWindowBuckets()}
*
* These values are stable - there's no peeking into a bucket until it is emitted
*
* These values get produced and cached in this class.
* You may query to find the latest rolling count of 2 events (executed/rejected) via {@link #getLatestCount(com.netflix.hystrix.HystrixEventType.ThreadPool)}.
*/
public class CumulativeThreadPoolEventCounterStream extends BucketedCumulativeCounterStream {
private static final ConcurrentMap streams = new ConcurrentHashMap();
private static final int ALL_EVENT_TYPES_SIZE = HystrixEventType.ThreadPool.values().length;
public static CumulativeThreadPoolEventCounterStream getInstance(HystrixThreadPoolKey threadPoolKey, HystrixThreadPoolProperties properties) {
final int counterMetricWindow = properties.metricsRollingStatisticalWindowInMilliseconds().get();
final int numCounterBuckets = properties.metricsRollingStatisticalWindowBuckets().get();
final int counterBucketSizeInMs = counterMetricWindow / numCounterBuckets;
return getInstance(threadPoolKey, numCounterBuckets, counterBucketSizeInMs);
}
public static CumulativeThreadPoolEventCounterStream getInstance(HystrixThreadPoolKey threadPoolKey, int numBuckets, int bucketSizeInMs) {
CumulativeThreadPoolEventCounterStream initialStream = streams.get(threadPoolKey.name());
if (initialStream != null) {
return initialStream;
} else {
synchronized (CumulativeThreadPoolEventCounterStream.class) {
CumulativeThreadPoolEventCounterStream existingStream = streams.get(threadPoolKey.name());
if (existingStream == null) {
CumulativeThreadPoolEventCounterStream newStream =
new CumulativeThreadPoolEventCounterStream(threadPoolKey, numBuckets, bucketSizeInMs,
HystrixThreadPoolMetrics.appendEventToBucket, HystrixThreadPoolMetrics.counterAggregator);
streams.putIfAbsent(threadPoolKey.name(), newStream);
return newStream;
} else {
return existingStream;
}
}
}
}
public static void reset() {
streams.clear();
}
private CumulativeThreadPoolEventCounterStream(HystrixThreadPoolKey threadPoolKey, int numCounterBuckets, int counterBucketSizeInMs,
Func2 reduceCommandCompletion,
Func2 reduceBucket) {
super(HystrixThreadPoolCompletionStream.getInstance(threadPoolKey), numCounterBuckets, counterBucketSizeInMs, reduceCommandCompletion, reduceBucket);
}
@Override
public long[] getEmptyBucketSummary() {
return new long[ALL_EVENT_TYPES_SIZE];
}
@Override
public long[] getEmptyOutputValue() {
return new long[ALL_EVENT_TYPES_SIZE];
}
public long getLatestCount(HystrixEventType.ThreadPool eventType) {
return getLatest()[eventType.ordinal()];
}
}