com.netflix.eureka.util.batcher.TrafficShaper Maven / Gradle / Ivy
/*
* Copyright 2015 Netflix, Inc.
*
* Licensed 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 com.netflix.eureka.util.batcher;
import com.netflix.eureka.util.batcher.TaskProcessor.ProcessingResult;
/**
* {@link TrafficShaper} provides admission control policy prior to dispatching tasks to workers.
* It reacts to events coming via reprocess requests (transient failures, congestion), and delays the processing
* depending on this feedback.
*
* @author Tomasz Bak
*/
class TrafficShaper {
/**
* Upper bound on delay provided by configuration.
*/
private static final long MAX_DELAY = 30 * 1000;
private final long congestionRetryDelayMs;
private final long networkFailureRetryMs;
private volatile long lastCongestionError;
private volatile long lastNetworkFailure;
TrafficShaper(long congestionRetryDelayMs, long networkFailureRetryMs) {
this.congestionRetryDelayMs = Math.min(MAX_DELAY, congestionRetryDelayMs);
this.networkFailureRetryMs = Math.min(MAX_DELAY, networkFailureRetryMs);
}
void registerFailure(ProcessingResult processingResult) {
if (processingResult == ProcessingResult.Congestion) {
lastCongestionError = System.currentTimeMillis();
} else if (processingResult == ProcessingResult.TransientError) {
lastNetworkFailure = System.currentTimeMillis();
}
}
long transmissionDelay() {
if (lastCongestionError == -1 && lastNetworkFailure == -1) {
return 0;
}
long now = System.currentTimeMillis();
if (lastCongestionError != -1) {
long congestionDelay = now - lastCongestionError;
if (congestionDelay >= 0 && congestionDelay < congestionRetryDelayMs) {
return congestionRetryDelayMs - congestionDelay;
}
lastCongestionError = -1;
}
if (lastNetworkFailure != -1) {
long failureDelay = now - lastNetworkFailure;
if (failureDelay >= 0 && failureDelay < networkFailureRetryMs) {
return networkFailureRetryMs - failureDelay;
}
lastNetworkFailure = -1;
}
return 0;
}
}