Re: Bug Found causing slowdown and errors... And a question on scope ofobjects

["Larry Loen" <lwloen@xxxxxxxxxx>]

Forget activiation groups and such.  Java is platform independent, so it
doesn't use such things.

If Joe invokes a JVM, his static variable will be different from the JVM
that Mary invokes separately.

If, on the other hand, Joe and Mary both interact with an application
(perhaps, via the web) that ends up being performed in different threads in
the same JVM, then they will share the static variables of each class.

The key is that it is the JVM that is the main boundary.  Each new JVM is a
bunch of new static variables.

The benefit from connection pooling is, at minimum, reuse of the expense of
creating the connection even for a JVM that consists entirely of one Java
application and thread.  It can be more savings, though.  If you want two
"jobs" to share the costs and benefits, structure your application so that
they end up as Java threads in the same JVM.

Just remember that they aren't jobs in that case, but true threads with all
the potential sharing that implies.


Larry W. Loen  -   Senior Linux, Java, and iSeries Performance Analyst
                          Dept HP4, Rochester MN