com.alibaba.metrics.ClusterHistogram Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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 com.alibaba.metrics;
import java.util.Arrays;
import java.util.Map;
/**
* A metric to calculate cluster histogram,
* since the the percentile can not be aggregated.
* @author wangtao 2019-01-15 15:00
*/
public abstract class ClusterHistogram implements Metric {
private static final int MAX_BUCKET_COUNT =
Integer.getInteger("com.alibaba.metrics.maxClusterHistogramBucketCount", 100);
protected long[] buckets;
public ClusterHistogram(final long[] buckets) {
if (buckets == null) {
this.buckets = new long[]{1, 5, 10, 25, 50, 75, 100, 250, 500, 750, 1000};
} else if (buckets.length == 0) {
throw new IllegalStateException("The number of buckets should not be null or 0.");
} else if (buckets.length > MAX_BUCKET_COUNT) {
throw new IllegalStateException("The number of buckets should be no larger than " + MAX_BUCKET_COUNT);
} else {
this.buckets = buckets;
this.buckets = new long[buckets.length+1];
for (int i = 0; i < buckets.length; i++) {
this.buckets[i] = buckets[i];
}
this.buckets[buckets.length] = Long.MAX_VALUE;
// ensure the input array is in ascending order
Arrays.sort(this.buckets);
}
}
public ClusterHistogram() {
this(null);
}
public abstract void update(long value);
public long[] getBuckets() {
return this.buckets;
}
/**
* get the bucket values since (including) the startTime, keyed by timestamp.
* @param startTime 查询起始时间, 单位是毫秒
* @return a map, keyed by timestamp, the value is a Map of the bucket and its value
* For example: 1234556789 -> { [0, 1) -> 1, [1, 10) -> 5, [10, 100) -> 3 }
* which means in timestamp 1234556789, there are 1 in [0, 1) bucket, 5 in [1, 10) bucket, 3 in [10, 100) bucket.
*/
public abstract Map> getBucketValues(long startTime);
}