janhoy commented on code in PR #96: URL: https://github.com/apache/solr/pull/96#discussion_r1310122961
########## solr/core/src/java/org/apache/solr/util/circuitbreaker/LoadAverageCircuitBreaker.java: ########## @@ -0,0 +1,115 @@ +/* + * 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; + +/** + * <p> + * Tracks current system load average and triggers if the specified threshold is breached. + * + * 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. + * //TODO: Use Codahale Meter to calculate the value locally. + * </p> + * + * <p> + * The configuration to define which mode to use and the trigger threshold are defined in + * solrconfig.xml + * </p> + */ +public class LoadAverageCircuitBreaker extends CircuitBreaker { + private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass()); + private static final OperatingSystemMXBean operatingSystemMXBean = ManagementFactory.getOperatingSystemMXBean(); + + private final boolean enabled; + private final 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(CircuitBreakerConfig config) { + super(config); + + this.enabled = config.getLoadAverageCBEnabled(); + this.loadAverageThreshold = config.getLoadAverageCBThreshold(); + } + + @Override + public boolean isTripped() { + if (!isEnabled()) { + return false; + } + + if (!enabled) { + return false; + } + + double localAllowedLoadAverage = getLoadAverageThreshold(); + double localSeenLoadAverage = calculateLiveLoadAverage(); + + if (localSeenLoadAverage < 0) { + if (log.isWarnEnabled()) { Review Comment: After #1725 this is less of a problem. Users choose one or more CB plugins to activate, and each is named and documented precisely. The legacy `CircuitBreakerManager` is a deprecated plugin of its own, and its `cpuThreshold` has not changed semantics, still uses load avg. -- 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
