/******************************************************************************* | |
* Copyright (c) 2011, 2013 Oracle and/or its affiliates. All rights reserved. | |
* This program and the accompanying materials are made available under the | |
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 | |
* which accompanies this distribution. | |
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html | |
* and the Eclipse Distribution License is available at | |
* http://www.eclipse.org/org/documents/edl-v10.php. | |
* | |
* Contributors: | |
* James Sutherland - initial API and implementation | |
******************************************************************************/ | |
package org.eclipse.persistence.annotations; | |
import java.lang.annotation.Retention; | |
import java.lang.annotation.Target; | |
import static java.lang.annotation.ElementType.FIELD; | |
import static java.lang.annotation.ElementType.METHOD; | |
import static java.lang.annotation.ElementType.TYPE; | |
import static java.lang.annotation.RetentionPolicy.RUNTIME; | |
/** | |
* RoundRobinPartitioning sends requests in a round robin fashion to the set of connection pools. | |
* It is for load-balancing read queries across a cluster of database machines. | |
* It requires that the full database be replicated on each machine, so does not support partitioning. | |
* The data should either be read-only, or writes should be replicated on the database. | |
* <p> | |
* Partitioning can be enabled on an Entity, relationship, query, or session/persistence unit. | |
* Partition policies are globally named to allow reuse, | |
* the partitioning policy must also be set using the @Partitioned annotation to be used. | |
* | |
* @see Partitioned | |
* @see org.eclipse.persistence.descriptors.partitioning.RoundRobinPartitioningPolicy | |
* @author James Sutherland | |
* @since EclipseLink 2.2 | |
*/ | |
@Target({TYPE, METHOD, FIELD}) | |
@Retention(RUNTIME) | |
public @interface RoundRobinPartitioning { | |
/** | |
* The name of the partition policy, names must be unique for the persistence unit. | |
*/ | |
String name(); | |
/** | |
* List of connection pool names to load balance across. | |
* Defaults to all defined pools in the ServerSession. | |
*/ | |
String[] connectionPools() default {}; | |
/** | |
* This allows for a set of database to be written to and kept in synch, | |
* and have reads load-balanced across the databases. | |
*/ | |
boolean replicateWrites() default false; | |
} |