WebSphere Extended Deployment, Version 6.0.x
             Operating Systems: AIX, HP-UX, Linux, Solaris, Windows, z/OS


Option A CMPs

This option is important for partitions with specific data access patterns. The problem with Option C Container-Managed Persistence (CMP)s with lifetime in cache is that WebSphere provides no API for removing such a CMP instance from the cache. WebSphere does provide a JMS mechanism that can remove an object, but this is not efficient for this scenario. So, objects cached using life time in cache cannot be removed programmatically from the cache by the application. This makes option C with lifetime cache unsuitable for partition data. The only option that will work is option A. Option A CMPs can be thought of as cached CMPs, although it is not technically a cache. The Java 2 Platform Enterprise Edition (J2EE) specification says that if an option A CMP method throws an unexpected exception then the bean instance must be removed from the container and the transaction currently active is rolled back. We will take advantage of this to implement the partition data cache.




Related concepts
Partition specific CMP data
Concept topic    

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Last updated: Nov 30, 2007 4:03:08 PM EST
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