Customizing JackRabbit Session for Performance

[sunild]

All,
   I have a content system implemented using JackRabbit 1.5.6, 
integrated with Spring Framework using SpringModules's JcrTemplate which 
needs to service requests in a multithreaded scenarios. Though I could 
optimize on the locking, I have not a substantial optimatization outcome 
on session.save. Hence in lieu of this, I am looking at options of 
customizing the JackRabbit Session implementation, for better 
performance. Could you please provide any pointers or reference links 
for the same.

Thanks
Sunil