[infinispan-dev] JBoss Libra

[Mircea Markus]

On 31 Jan 2012, at 09:34, Bela Ban wrote:

> IMO, measuring object size using java.lang.instrument is not a good 
> idea: first of all, it's probably very slow and the time to do so is 
> linear to the number of live objects.
+1
I remember prototyping this for JBossCache and the harness and that's what I found as well. 
> Second, this probably takes into 
> acount only objects in the cache, but not the cache structures used by 
> Infinispan, JGroups and so on...
> 
> The approach I've recommended before is to trigger an eviction policy 
> based on free/available memory. This can easily be fetched from the JVM 
> via JMX...
..or keep the in-memory data in serialized form (byte[]) - that can be counted - and add an empiric factor  (TBD) for the harness/ISPN structure that holds the data. AFAIK coherence does this.