Myasuka commented on a change in pull request #15119: URL: https://github.com/apache/flink/pull/15119#discussion_r599338577
########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/state/metrics/LatencyTrackingStateConfig.java ########## @@ -0,0 +1,117 @@ +/* + * 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.flink.runtime.state.metrics; + +import org.apache.flink.configuration.ReadableConfig; +import org.apache.flink.configuration.StateBackendOptions; +import org.apache.flink.metrics.MetricGroup; +import org.apache.flink.util.Preconditions; + +import java.io.Serializable; + +/** Config to create latency tracking state metric. */ +public class LatencyTrackingStateConfig { + + private final MetricGroup metricGroup; + + private final boolean enabled; + private final int sampleInterval; + private final long slidingWindow; + + LatencyTrackingStateConfig( + MetricGroup metricGroup, boolean enabled, int sampleInterval, long slidingWindow) { + this.metricGroup = metricGroup; + this.enabled = enabled; + this.sampleInterval = sampleInterval; + this.slidingWindow = slidingWindow; + } + + public boolean isEnabled() { + return enabled; + } + + public MetricGroup getMetricGroup() { + return metricGroup; + } + + public long getSlidingWindow() { + return slidingWindow; + } + + public int getSampleInterval() { + return sampleInterval; + } + + public static LatencyTrackingStateConfig disabled() { + return newBuilder().setEnabled(false).build(); + } + + public static Builder newBuilder() { + return new Builder(); + } + + public static class Builder implements Serializable { + private static final long serialVersionUID = 1L; + + private boolean enabled = StateBackendOptions.LATENCY_TRACK_ENABLED.defaultValue(); + private int sampleInterval = + StateBackendOptions.LATENCY_TRACK_SAMPLE_INTERVAL.defaultValue(); + private long slidingWindow = + StateBackendOptions.LATENCY_TRACK_SLIDING_WINDOW.defaultValue(); + private MetricGroup metricGroup; + + public Builder setEnabled(boolean enabled) { + this.enabled = enabled; + return this; + } + + public Builder setSampleInterval(int sampleInterval) { + this.sampleInterval = sampleInterval; + return this; + } + + public Builder setSlidingWindow(long slidingWindow) { + this.slidingWindow = slidingWindow; + return this; + } + + public Builder setMetricGroup(MetricGroup metricGroup) { + this.metricGroup = metricGroup; + return this; + } + + public Builder configure(ReadableConfig config) { + this.setEnabled(config.get(StateBackendOptions.LATENCY_TRACK_ENABLED)) + .setSampleInterval( + config.get(StateBackendOptions.LATENCY_TRACK_SAMPLE_INTERVAL)) + .setSlidingWindow(config.get(StateBackendOptions.LATENCY_TRACK_SLIDING_WINDOW)); + return this; + } + + public LatencyTrackingStateConfig build() { + if (enabled) { + Preconditions.checkNotNull( + metricGroup, "Metric group cannot be null if latency tracking is enabled."); + Preconditions.checkArgument(sampleInterval >= 1); Review comment: After reading some more references, I think `sample interval` should be okay as I actually select [systematic sampling](https://en.wikipedia.org/wiki/Systematic_sampling) in which the `sample interval` just have such definition. If we select `record-1` as the first one, and choose 100 as the interval. The next record to select is `record-101`. -- 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
