cshannon commented on code in PR #4558: URL: https://github.com/apache/accumulo/pull/4558#discussion_r1605567223
########## core/src/main/java/org/apache/accumulo/core/logging/ConditionalLogger.java: ########## @@ -0,0 +1,193 @@ +/* + * 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 + * + * https://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.accumulo.core.logging; + +import java.time.Duration; +import java.util.Arrays; +import java.util.List; +import java.util.concurrent.ConcurrentMap; +import java.util.function.BiFunction; + +import org.apache.accumulo.core.util.Pair; +import org.slf4j.Logger; +import org.slf4j.Marker; +import org.slf4j.event.Level; +import org.slf4j.helpers.AbstractLogger; + +import com.github.benmanes.caffeine.cache.Cache; +import com.github.benmanes.caffeine.cache.Caffeine; + +/** + * Logger that wraps another Logger and only emits a log message once per the supplied duration. + * + */ +public abstract class ConditionalLogger extends AbstractLogger { + + private static final long serialVersionUID = 1L; + + /** + * A Logger implementation that will log a message at the supplied elevated level if it has not + * been seen in the supplied duration. For repeat occurrences the message will be logged at the + * level used in code (which is likely a lower level). Note that the first log message will be + * logged at the elevated level because it has not been seen before. + */ + public static class EscalatingLogger extends DeduplicatingLogger { + + private static final long serialVersionUID = 1L; + private final Level elevatedLevel; + + public EscalatingLogger(Logger log, Duration threshold, Level elevatedLevel) { + super(log, threshold); + this.elevatedLevel = elevatedLevel; + } + + @Override + protected void handleNormalizedLoggingCall(Level level, Marker marker, String messagePattern, + Object[] arguments, Throwable throwable) { + + if (arguments == null) { + arguments = new Object[0]; + } + if (!condition.apply(messagePattern, Arrays.asList(arguments))) { + delegate.atLevel(level).addMarker(marker).setCause(throwable).log(messagePattern, + arguments); + } else { + delegate.atLevel(elevatedLevel).addMarker(marker).setCause(throwable).log(messagePattern, + arguments); + } + + } + + } + + /** + * A Logger implementation that will suppress duplicate messages within the supplied duration. + */ + public static class DeduplicatingLogger extends ConditionalLogger { + + private static final long serialVersionUID = 1L; + + public DeduplicatingLogger(Logger log, Duration threshold) { + super(log, new BiFunction<>() { + + private final Cache<Pair<String,List<Object>>,Boolean> cache = + Caffeine.newBuilder().expireAfterWrite(threshold).maximumSize(250).build(); + + private final ConcurrentMap<Pair<String,List<Object>>,Boolean> cacheMap = cache.asMap(); + + /** + * Function that will return true if the message has not been seen in the supplied duration. + * + * @param msg log message + * @param args log message arguments + * @return true if message has not been seen in duration, else false. + */ + @Override + public Boolean apply(String msg, List<Object> args) { + return cacheMap.putIfAbsent(new Pair<>(msg, args), true) == null; Review Comment: This LGTM now for adding to the cache, the only thing to point out is there is probably a chance the equals/hashcode could not be considered equal when it is if there are objects passed in the list for logging that are not implement hashcode/equals and the references are difference between logging runs. This is probably ok as it's best effort for the logging reduction but just wanted to point that out. If it's a problem in the future we could change it and just convert the objects to strings using toString() to compare. -- 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: notifications-unsubscr...@accumulo.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
