apovzner commented on a change in pull request #9114: URL: https://github.com/apache/kafka/pull/9114#discussion_r464810412
########## File path: clients/src/main/java/org/apache/kafka/common/metrics/stats/TokenBucket.java ########## @@ -0,0 +1,83 @@ +/* + * 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 org.apache.kafka.common.metrics.stats; + +import java.util.concurrent.TimeUnit; +import org.apache.kafka.common.metrics.MeasurableStat; +import org.apache.kafka.common.metrics.MetricConfig; + +public class TokenBucket implements MeasurableStat { + private final TimeUnit unit; + private double credits; + private long lastUpdateMs; + + public TokenBucket() { + this(TimeUnit.SECONDS); + } + + public TokenBucket(TimeUnit unit) { + this.unit = unit; + this.credits = 0; + this.lastUpdateMs = 0; + } + + @Override + public double measure(final MetricConfig config, final long timeMs) { + if (config.quota() == null) + return Long.MAX_VALUE; + final double quota = config.quota().bound(); + final double burst = (config.samples() - 1) * convert(config.timeWindowMs()) * quota; + refill(quota, burst, timeMs); + return this.credits; + } + + @Override + public void record(final MetricConfig config, final double value, final long timeMs) { + if (config.quota() == null) + return; + final double quota = config.quota().bound(); + final double burst = (config.samples() - 1) * convert(config.timeWindowMs()) * quota; Review comment: If we want the burst to be more similar to original behavior, it seems like this should be `#samples`. With the current implementation, we can do 1 unit of work in the oldest window and then accept a burst right at the end of the last (not full yet) sample. Which means that the max burst size is almost at #samples * quota (if sample = 1 sec, quota is in units/second). Does this sound right to you? Also, I think we should take into account `config.timeWindowMs`, because it could be something other than 1 second. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
