| /* |
| * Copyright (c) 2011, 2020 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 v. 2.0 which is available at |
| * http://www.eclipse.org/legal/epl-2.0, |
| * or the Eclipse Distribution License v. 1.0 which is available at |
| * http://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause |
| */ |
| |
| // 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; |
| } |