cpoerschke commented on code in PR #96: URL: https://github.com/apache/solr/pull/96#discussion_r1327156515
########## solr/core/src/java/org/apache/solr/util/circuitbreaker/LoadAverageCircuitBreaker.java: ########## @@ -0,0 +1,109 @@ +/* + * 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 java.lang.invoke.MethodHandles; +import java.lang.management.ManagementFactory; +import java.lang.management.OperatingSystemMXBean; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Tracks current system load average and triggers if the specified threshold is breached. + * + * <p>This circuit breaker gets the load average (length of the run queue) over the last minute and + * uses that data to take a decision. We depend on OperatingSystemMXBean which does not allow a + * configurable interval of collection of data. + */ +public class LoadAverageCircuitBreaker extends CircuitBreaker { + private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass()); + private static final OperatingSystemMXBean operatingSystemMXBean = + ManagementFactory.getOperatingSystemMXBean(); + + private double loadAverageThreshold; + + // Assumption -- the value of these parameters will be set correctly before invoking + // getDebugInfo() + private static final ThreadLocal<Double> seenLoadAverage = ThreadLocal.withInitial(() -> 0.0); + + private static final ThreadLocal<Double> allowedLoadAverage = ThreadLocal.withInitial(() -> 0.0); + + public LoadAverageCircuitBreaker() { + super(); + } + + @Override + public boolean isTripped() { + double localAllowedLoadAverage = getLoadAverageThreshold(); + double localSeenLoadAverage = calculateLiveLoadAverage(); + + if (localSeenLoadAverage < 0) { + if (log.isWarnEnabled()) { + String msg = "Unable to get load average"; + + log.warn(msg); + } + + return false; + } + + allowedLoadAverage.set(localAllowedLoadAverage); + + seenLoadAverage.set(localSeenLoadAverage); + + return (localSeenLoadAverage >= localAllowedLoadAverage); + } + + @Override + public String getDebugInfo() { + + if (seenLoadAverage.get() == 0.0 || allowedLoadAverage.get() == 0.0) { + log.warn( + "LoadAverageCircuitBreaker's monitored values (seenLoadAverage, allowedLoadAverage) not set"); + } + + return "seenLoadAverage=" + + seenLoadAverage.get() + + " allowedLoadAverage=" + + allowedLoadAverage.get(); + } + Review Comment: to match #1890 ```suggestion ``` -- 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
