Synopsis

This project is an implementation of an OpenJPA plugin for distributed caching with a Redis backend. I've implemented both a DataCache and a QueryCache plugin.

Keep in mind that using these plugins means that the underlying database must only be written through a data model that uses this cache; otherwise you must flush the Redis cache if you write the database independently.

Code Example

TBD

Installation

I haven't deployed to Maven yet due to lack of tests, but you may clone the github repository and then run mvn install from the root directory.

API Reference

Once you've run mvn install above, you may include the plugin in your persistence.xml as follows:

<persistence>
	<persistence-unit name="persistence-unit-name" transaction-type="JTA">
		<properties>
			<property name="openjpa.DataCache" value="com.github.jzila.cache.RedisDataCache"/>
			<property name="openjpa.QueryCache" value="com.github.jzila.cache.RedisQueryCache"/>
			<property name="openjpa.RemoteCommitProvider" value="sjvm"/>
		</properties>
	</persistence-unit>
</persistence>

You must also create a file named openjpa_redis.xml in your classpath. If you do not do this, the defaults will apply (localhost:6379 as the only server, and an empty prefix). This file should appear as follows (placeholders for localhost):

<redis>
	<!-- The list of servers that will be used for the distributed cache. Uses
		ShardedJedis to perform the consistent hashing -->
    <servers>
        <server>
            <host>localhost</host>
            <port>6379</port>
        </server>
    </servers>
	<!-- The prefix that will be used to preface the keys in your Redis database -->
    <prefix>foo</prefix>
</redis>

If you use this plugin with a Tomcat or TomEE server, you must include all the dependencies in your Tomcat's /lib folder. This is because Tomcat initializes OpenJPA independently of each webapp, and so the jars included in the web app won't be visible to the OpenJPA classes.

Tests

TBD

Contributors

This project is entirely hosted on GitHub. If you wish to file an issue, you may do so by submitting a GitHub issue against this project. You may also submit pull requests from your own fork.

License

Copyright 2014 John Zila

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.