How is clustering implemented?

hey ejb gurus

i am looking for some info on how clustering support is actually implemented in application servers? i mean to say that, for instance, we have a bare-bones application server and if we want to support clustering in that server, how do we go about doing it?

any resources which talk about this will possibly be of use..... please help.

thanks a lot

[401 byte] By [jinnjee] at [2007-9-26 2:14:22]