Revision as of 17:32, 17 June 2010

Integrating EclipseLink with EhCache Network Attached Memory

Purpose

• Integration of EclipseLink EclipseLink with the Ehcache Distributed Cache - a (L2) shared cache.
• This investigation is specific to Ehcache. See the following page for Oracle TopLink Grid (Coherence based distributed shared (L2) cache) that currently integrates with EclipseLink.

Summary

• This document in progress as of 20100326 details how to integrate EclipseLink with Ehcache. We will explore the Ehcache open source version - see (Distributed JVM-aware transparent Cache).
• The goal of this investigation is to define and publish a procedure on using EclipseLink as the JPA provider in a distributed memory application based on the EhCache Caching API.
• The motivation of this work is in learning and leveraging the ehcache 2nd level cache API, and investigating details/issues of the technical space surrounding distributing caching in general as described in the paper on the new Java5 memory model by William Pugh - The Java Memory Model.
• I am interested in the following...
  • Use as a JVM bridge, or JVM agnostic application (IE: Mixed J9, SUN, JRockit implementations)
  • Q) If orm relationships are computed, then how to override outside of using @OneToMany(mappedBy="") annotation and differentiate between unidirectional and bidirectional 1:M relationships.

Setup

Tutorial Source

Development Environment

• We will be using a cluster of 3 identical machines (Low power P4-630 CPU's) running 32 bit versions of the SUN JDK 1.6.0_18

Prerequisites

• We will attempt to keep all software open-source if possible.

Setup Cluster

• We are using 3 P4-630 32 bit machines and 1 Corei7 64 bit machine.

Install Eclipse EE

• We are using Eclipse 3.5 Galileo EE edition (32 bit).

Install a Database

• We will start with Derby 10 but possibly use MySQL if we run into any limitations.

Install Application Servers

• We will use GlassFish V3 Final Open Source Edition (the JEE6 RI). See the JPA tutorial for GlassFish V3 for a quickstart run.

Install JPA provider

• We will be using EclipseLink 2.0 (the JEE6 RI) that is shipped with GlassFish.

Install EhCache

Design Issues

Open Issues

References

• 219683: Design and Implement Interception points in EclipseLink - In EclipseLink 1.0 (2008)
• Oracle TopLink Grid - A Coherence based distributed shared (L2) cache that integrates with EclipseLink JPA
• Terracotta + GlassFish + EclipseLink
• Terracotta Inc. Discussion Forum
• Terracotta forum post - integration request 20080812 3rd level Cache
• Terracotta forum post - integration request 20090518 TIM
• Terracotta forum post - integration request 20090614 Spring EclipseLink
• Terracotta forum post - integration request 20090616 Custom ClassLoader
• EclipseLink coordinated cache integration with Terracotta 20081221 - request
• See Chapter 6 p.131 of "Terracotta - Cluster the JVM for Spring, Hibernate and POJO Scalability" - available from Apress.

External Documentation

• Clustering Spring Framework with Terracotta
• Terracotta Distributed Ehcache for Hibernate Express Installation