com.hazelcast.core.PartitionAware Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2013, 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;
/**
* PartitionAware mean that data will be based in the same member based on partition key
* and implementing tasks will be executed on the {@link #getPartitionKey()}'s owner member.
*
* This achieves data affinity. Data or execution occurs on the same partition.
*
* In Hazelcast, disparate data structures will be stored on the same partition, simply
* based on partition key. So for example if "Steve" was used, then the following would be on one partition:
*
* - a customers IMap with an entry of key "Steve
* - an orders IMap using a customer key type implementing PartitionAware with key "Steve
* - any queue named "Steve"
* - any PartitionAware object with partition key "Steve
*
*
* So if you had a {@link com.hazelcast.core.IExecutorService} which needed to deal with a customer and a customer's
* orders, optimal performance will be achieved by putting them on the same partition.
*
* {@link com.hazelcast.core.DistributedObject} also has a notion of partition key which is of type String. So
* to ensure the same partition as distributed Objects Strings should be used for the partition key.
*
* @see com.hazelcast.core.DistributedObject
* @param key type
*/
public interface PartitionAware {
/**
* The key that will be used by Hazelcast to specify the partition.
* You should give the same key for objects that you want be in the same partition.
*
* @return partition key
*/
T getPartitionKey();
}