org.apache.logging.log4j.core.async.DiscardingAsyncQueueFullPolicy Maven / Gradle / Ivy
/*
* 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.logging.log4j.core.async;
import java.util.Objects;
import java.util.concurrent.atomic.AtomicLong;
import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.status.StatusLogger;
/**
* Discarding router extends the DefaultAsyncQueueFullPolicy by first verifying if the queue is fuller than the specified
* threshold ratio; if this is the case, log events {@linkplain Level#isMoreSpecificThan(Level) more specific} than
* the specified threshold level are dropped. If this is not the case, the {@linkplain DefaultAsyncQueueFullPolicy
* default routing} rules hold.
*/
public class DiscardingAsyncQueueFullPolicy extends DefaultAsyncQueueFullPolicy {
private static final Logger LOGGER = StatusLogger.getLogger();
private final Level thresholdLevel;
private final AtomicLong discardCount = new AtomicLong();
/**
* Constructs a router that will discard events {@linkplain Level#isLessSpecificThan(Level) equal or less specific}
* than the specified threshold level when the queue is full.
*
* @param thresholdLevel level of events to discard
*/
public DiscardingAsyncQueueFullPolicy(final Level thresholdLevel) {
this.thresholdLevel = Objects.requireNonNull(thresholdLevel, "thresholdLevel");
}
@Override
public EventRoute getRoute(final long backgroundThreadId, final Level level) {
if (level.isLessSpecificThan(thresholdLevel)) {
if (discardCount.getAndIncrement() == 0) {
LOGGER.warn(
"Async queue is full, discarding event with level {}. "
+ "This message will only appear once; future events from {} "
+ "are silently discarded until queue capacity becomes available.",
level,
thresholdLevel);
}
return EventRoute.DISCARD;
}
return super.getRoute(backgroundThreadId, level);
}
public static long getDiscardCount(final AsyncQueueFullPolicy router) {
if (router instanceof DiscardingAsyncQueueFullPolicy) {
return ((DiscardingAsyncQueueFullPolicy) router).discardCount.get();
}
return 0;
}
public Level getThresholdLevel() {
return thresholdLevel;
}
}