sigram commented on code in PR #1905: URL: https://github.com/apache/solr/pull/1905#discussion_r1321979342
########## solr/core/src/java/org/apache/solr/util/circuitbreaker/AveragingMetricProvider.java: ########## @@ -0,0 +1,80 @@ +/* + * 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.solr.util.circuitbreaker; + +import com.google.common.util.concurrent.AtomicDouble; +import java.io.Closeable; +import java.util.concurrent.Executors; +import java.util.concurrent.ScheduledExecutorService; +import java.util.concurrent.TimeUnit; +import org.apache.solr.common.util.ExecutorUtil; +import org.apache.solr.common.util.SolrNamedThreadFactory; +import org.apache.solr.logging.CircularList; + +/** Averages the metric value over a period of time */ +public class AveragingMetricProvider implements Closeable { + private final CircularList<Double> samplesRingBuffer; + private ScheduledExecutorService executor; + private final AtomicDouble currentAverageValue = new AtomicDouble(-1); + + /** + * Creates an instance with an executor that runs every sampleInterval seconds and averages over + * numSamples samples. + * + * @param metricProvider metric provider that will provide a value + * @param numSamples number of samples to calculate average for + * @param sampleInterval interval between each sample + */ + public AveragingMetricProvider( Review Comment: Hmm, not sure what you mean by event/count oriented... it does the counting, true, but it also keeps track of `ExponentialMovingAverages`, which in turn uses a bunch of EWMAs. "Rate" in its terminology is exactly the moving average of values that are recorded into it by `EWMA.update(n)` method (or `Meter.mark(n)`). Edit: in other words, calling `EWMA.update(metricProvider.getMetricValue())` and then `EWMA.getRate` would give you a similar average value over time, only without allocating any actual buffer for samples. -- 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: issues-unsubscr...@solr.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@solr.apache.org For additional commands, e-mail: issues-h...@solr.apache.org
