com.hazelcast.internal.cluster.fd.PingFailureDetector Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2018, Hazelcast, Inc. All Rights Reserved.
*
* 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.hazelcast.internal.cluster.fd;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Ping based failure detector. (OSI Layer 3)
* This failure detector uses an absolute number of missing ping attempts.
* After that many attempts, an endpoint is considered as dead/unavailable.
*/
public class PingFailureDetector {
private final int maxPingAttempts;
private final ConcurrentMap pingAttempts = new ConcurrentHashMap();
public PingFailureDetector(int maxPingAttempts) {
this.maxPingAttempts = maxPingAttempts;
}
public int heartbeat(E endpoint) {
return getAttempts(endpoint).getAndSet(0);
}
public void logAttempt(E endpoint) {
getAttempts(endpoint).incrementAndGet();
}
public boolean isAlive(E endpoint) {
AtomicInteger attempts = pingAttempts.get(endpoint);
return attempts != null && attempts.get() < maxPingAttempts;
}
public void remove(E endpoint) {
pingAttempts.remove(endpoint);
}
public void reset() {
pingAttempts.clear();
}
private AtomicInteger getAttempts(E endpoint) {
AtomicInteger existing = pingAttempts.get(endpoint);
AtomicInteger newAttempts = null;
if (existing == null) {
newAttempts = new AtomicInteger();
existing = pingAttempts.putIfAbsent(endpoint, newAttempts);
}
return existing != null ? existing : newAttempts;
}
}