attributeCache distribution only over RMI

A customer has raised some questions regarding ehcache configuration. 

1. Why there are two ehcache_hibernate.xml available in JRS webapp- "jasperserver-pro/WEB-INF/" and "jasperserver-pro/WEB-INF/classes" while there is only one ehcache.xml? Why we need to modify both these files for enabling ehcache? 
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one in WEB-INF is used for compilation/installation 
one in WEB-INF/classes is the one that is used by application, so if you need to make changes there that's the only one needed. 
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2. 'attributeCache' configured in ehcache.xml, only has RMI configurations to allow distribution for this cache. What if I choose, JMS to replicate the ehcache. In that case, what needs to be the configuration for 'attributeCache' distribution. Please check and revert on this ambiguity in the configuration for 'attributeCache' distribution. 
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Hello James, I did some investigation in the source code and svn. It seams that JMS distribution was introduced in parallel project to User Attributes project ( where they introduced the 'attributeCache' ). I think JMS configuration was not available in JRS at the time when 'attributeCache' was developing and soon after merged into the main code line ( int 2 month) JMS distribution has arrived (developed most likely by the different team). 
attributeCache - it is NOT setup for replication, not even JMX, those comments inside the file are work in progress 
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3. In WEB-INF/ehcache_hibernate.xml & WEB-INF/classes/ehcache_hibernate.xml files, both RMI and JMS configurations are provided for 'defaultRepoCache' and 'aclCache'. What will be the impact, if I only enable cache distribution of 'defaultRepoCache' and 'aclCache' over JMS and do not enable 'attributeCache' over RMI. 
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From Eugene's comments it seems this isn't fully implemented yet. So the impact it would have it a bit of a moot point, but as Stas said the impact of not having this feature would be that users profile atttributes will not be replicated across the cluster if they are updated live. 
At one point we had distributed caches defined in both ehcache.xml and ehcache_hibernate.xml but that had been consolidated into one file. 
attributeCache was never tested for replication but impact of this not been replicated shouldn't be anything huge anyways. 
According to Eugene, attributeCache was never tested for replication, and the comment in that file can be ignored. 
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4. Why ehcache,xml has listener factories defined only for RMI replication and nothing is specified for JMS and/or AWS? 
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In the Tibbr thread Stas mentioned that the JMS distribution implementation and the user attributes project that introduced the attibuteCache were completely separate and gave some indication as to why attributeCache does not appear in the JMS config. 
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Hope this will help if you have similar questions.