Servlet->SLSB->Singleton

[Pearlo Muthukumaran]

I need some design inputs for caching
150 KB sized objects in the main memory for
performance requirements.
I am planning to use a hastable where I shall store a byte array chunk of above size with some name assigned to it and shall encapsulate it within a management object for getting , putting etc., the expected size is 60 objects at any point of time.
Please let me know whether above will serve the
purpose of my intention to build a quick
"MAIN-MEMORY" Database?
Something like below is the requirement
Servlet->SLSB->Singleton holding the hashtable
But in this case I see that deployment will demand that all the three components will have to reside in the same physical server. If I am going to cluster then the real requirement of "performance through in-memory database (HASHTABLE)" will be unpredicatble.
Any suggestions? I cannot get away with the Servlet and SLSB and implement them as simple Java Classes - another requirement
How to effectively address the above issue?
Rgds
Muthu