Re: Q: Multiple EJB servers with one DB

[Javier Borrajo]

Title: Q: Multiple EJB servers with one DB

Assume there's one (huge) DB to which we want to provide access through EJB. Assume that there're multiple EJB servers that should provide access to this DB. Assume that a row in the DB is represented by an entity bean. Now, if an entity bean has been instantiated at BOTH servers, and then updated from one server, how is the second bean (at the 2nd server) updated? (This is even more problematic if caching is used) I understand second bean only needs to be updated when involved in next transaction, so there is no integrity problem but yes a performance problem.   Data caching is only possible/recommended if the EJB server does not share the database with any other system, other EJB servers included, unless the vendor implements multiple node data caching mechanisms.   Regards       Javier Borrajo     www.tid.es