[jboss-dev-forums] [Design of JBossCache] - Re: Redesigning eviction

[andyredhead]

Hi,

anonymous wrote : 
  | When is an eviction needed? When we're running out of memory. If memory was infinite, we wouldn't need evictions.
  | 

I'm not sure this is the only scenario where an object needs evicting.  I think another criteria would be that an object should be evicted when its state has become "stale".  Sometimes the logic around what makes "stale state" is going to be so application specific that there could be no expectation that the cache works it out, however there are plenty of occasions where a broad-brush approach such as "objects under this sub-branch get evicted after X minutes".

I have a couple of applications in production where JBossCache is used as a 2nd level cache for Hibernate and a time based eviction policy suits the application very well.

I guess the point of this post is:

1) Pointing out that memory consumption is not the only driver for eviction

2) A simple policy (with simple configuration) will suite "real world" applications just fine, making it overly complicated to do easy stuff would be painful for us "simple users" (well, me anyway ;)

3) As what's there kind of works, perhaps the effort that would go into this would be better off put into something else for now (like standardising the AOP framework for the pojo cache, even better to be standardising on the JBOss AOP framework so that those of us who are tied to using the appserver don't have to learn another AOP framework or worry about how a different AOP framework will interact with JBoss AOP thats already being used in other parts of their applications...)

Cheers,

Andy 

View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4065672#4065672

Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4065672