hachikuji commented on code in PR #13207: URL: https://github.com/apache/kafka/pull/13207#discussion_r1105000782
########## raft/src/main/java/org/apache/kafka/raft/internals/TimeRatio.java: ########## @@ -0,0 +1,78 @@ +/* + * 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.raft.internals; + +import org.apache.kafka.common.metrics.MeasurableStat; +import org.apache.kafka.common.metrics.MetricConfig; + +/** + * Maintains an approximate ratio of the duration of a specific event + * over all time. For example, this can be used to compute the ratio of + * time that a thread is busy or idle. The value is approximate since the + * measurement and recording intervals may not be aligned. + * + * Note that the duration of the event is assumed to be small relative to + * the interval of measurement. + * + */ +public class TimeRatio implements MeasurableStat { + private long intervalStartTimestampMs = -1; + private long lastRecordedTimestampMs = -1; + private double totalRecordedDurationMs = 0; + + private final double defaultRatio; + + public TimeRatio(double defaultRatio) { + this.defaultRatio = defaultRatio; + } + + @Override + public double measure(MetricConfig config, long currentTimestampMs) { + if (lastRecordedTimestampMs < 0) { + // Return the default value if no recordings have been captured. + return defaultRatio; + } else { + // We measure the ratio over the + double intervalDurationMs = Math.max(lastRecordedTimestampMs - intervalStartTimestampMs, 0); + final double ratio; + if (intervalDurationMs == 0) { + ratio = defaultRatio; + } else if (totalRecordedDurationMs > intervalDurationMs) { + ratio = 1.0; + } else { + ratio = totalRecordedDurationMs / intervalDurationMs; + } + + // The next interval begins at the + intervalStartTimestampMs = lastRecordedTimestampMs; + totalRecordedDurationMs = 0; + return ratio; + } + } + + @Override + public void record(MetricConfig config, double value, long currentTimestampMs) { + if (intervalStartTimestampMs < 0) { + // Discard the initial value since the value occurred prior to the interval start + intervalStartTimestampMs = currentTimestampMs; Review Comment: Yeah, the awkward part of this patch is the reliance on the measuring interval. We might be able to do without it if we tracked the non-poll time as well, but we'd still need some notion of a window of measurement. -- 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. To unsubscribe, e-mail: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
