Hi,

I have a serious performance (and memory) problem in production that is due to the fact that my persistence context is overwhelmed with thousands of template entities (e.g. FormTemplate, FieldTemplate, etc.) which are read-only in production but read-write in pre-production where a BA may update a template. For what it’s worth, the FormTemplate contains a OneToMany collection of FieldTemplates (which, like the entities, are 2nd Level cached). Because of the need to load FormTemplates and FieldTemplates (and other template entities) for most transactions, the dirty checking that occurs again and again is a major performance problem as my application is full of query-modify-query-modify scenarios. With that said, I’m looking for the best way to go about disabling the dirty-checking in production for these template entities. I am leaning towards having two separate configurations: production and pre-production. The production configuration would declare template entities to be immutable and the cache concurrency strategy for each template entity/collection to be READ_ONLY. The pre-production configuration would declare template entities to be mutable and the cache concurrency strategy for each template entity/collection to be NONSTRICT_READ_WRITE. Assuming that this is a viable approach, I believe I would have to move away from an annotation configuration to an xml configuration (to avoid having to modify source code).

JBoss AS 5.1
Hibernate 3.3.1

Please advise. Sincerely, Tom

I should have stated that performance is not a major consideration in our pre-production environment. I should have also stated that I've been poring over Hibernate documentation, forums, etc. and while I've learned a lot about immutable entities, read-only queries, cache strategies, and more, I could really use an expert's advice.

Tom

An update...

I am currently leveraging an EntityListener to disable dirty checking...


This has a shortcoming in that a snapshot of the entity is constructed before postLoad runs.

With that said, I really want to declare the class immutable and use setReadOnly(entity, false) to re-enable dirty checking in the event that the entity does need to be changed. But, from what I've read in http://docs.jboss.org/hibernate/core/3.5/reference/en/html/readonly.html, it appears that I cannot do that...



Please advise... Tom

Unfortunately, using @PostLoad to disable dirty checking (for the template objects) has proven to be more of a performance downgrade than otherwise. While some operations have gotten faster, more have gotten slower (some as much as 20-30%).

I really could use some advice.

And I'm seeing more garbage collection in a one-hour 10 user test (using Web Load).