com.hazelcast.core.OutOfMemoryHandler 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.core;
import com.hazelcast.instance.OutOfMemoryHandlerHelper;
/**
* Handler for OutOfMemoryError.
*
* When an OutOfMemoryError is caught by Hazelcast threads,
* OutOfMemoryHandler is called for ALL HazelcastInstances
* known by the current JVM (actually ClassLoader).
*
*
*
* Warning: OutOfMemoryHandler may not be called even if JVM throws
* OutOfMemoryError
* because the error may be thrown from an external (user) thread, so
* Hazelcast may not be informed about OutOfMemoryError.
*
*
* @see OutOfMemoryError
* @see Hazelcast#setOutOfMemoryHandler(OutOfMemoryHandler)
*
*/
public abstract class OutOfMemoryHandler {
/**
* When an OutOfMemoryError is caught by Hazelcast threads,
* this method is called for ALL HazelcastInstances
* knows by current JVM (actually ClassLoader).
*
*
* User can shutdown the HazelcastInstance, call System.exit(),
* just log the error, etc.
* The default handler tries to close socket connections to other nodes and shutdown the
* HazelcastInstance.
*
*
*
* Warning: OutOfMemoryHandler may not be called even if JVM throws
* OutOfMemoryError
* because the error may be thrown from an external (user) thread
* and Hazelcast may not be informed about OutOfMemoryError.
*
*
* @see OutOfMemoryHandler#tryCloseConnections(HazelcastInstance)
* @see OutOfMemoryHandler#tryShutdown(HazelcastInstance)
*
* @param oome OutOfMemoryError thrown by JVM
* @param hazelcastInstances All HazelcastInstances known by JVM,
* can include inactive or NULL instances.
*/
public abstract void onOutOfMemory(OutOfMemoryError oome, HazelcastInstance[] hazelcastInstances);
/**
* Decides if the OutOfMemoryError thrown will be handled by this OutOfMemoryHandler or not.
* If true is return, {@link #onOutOfMemory(OutOfMemoryError, HazelcastInstance[])} will be called
* to handle error, otherwise OutOfMemoryError will be ignored.
*
* @param oome OutOfMemoryError thrown by JVM
* @return true if OutOfMemoryError will be handled, false otherwise
*/
public boolean shouldHandle(OutOfMemoryError oome) {
return true;
}
/**
* Tries to close the server socket and connections to other HazelcastInstances.
*
* @param hazelcastInstance the Hazelcast instance to close server socket
*/
protected final void tryCloseConnections(HazelcastInstance hazelcastInstance) {
OutOfMemoryHandlerHelper.tryCloseConnections(hazelcastInstance);
}
/**
* Tries to shutdown HazelcastInstance forcefully;
* including closing sockets and connections, stopping threads, etc.
*
* @param hazelcastInstance the Hazelcast instance to shutdown
*/
protected final void tryShutdown(final HazelcastInstance hazelcastInstance) {
OutOfMemoryHandlerHelper.tryShutdown(hazelcastInstance);
}
}