Article:
  Software Infrastructure Bottlenecks in J2EE
Subject:   Similar results
Date:   2005-01-20 12:13:09
From:   whartung
We found similar results in some of our testing. We were loading the server and running tests by giving the server varying numbers of CPUs. We found, simply, that while muliple CPU's gave us more throughput, it didn't scale as well as it could have, and that, for example, running two instances on 2 CPU's each of a 4 CPU machine gave us better utilization than one instance on the same 4 CPU machine.


There were obviously some internal bookkeeping or synchronization issues within the application server that was holding the overall application back (we came to refer to this unseen overhead as "Dark Matter", as it was pretty well impossible to actually measure it, but easy to see the results of its effects).