Preliminary tests

The ORB is affected by problems with the underlying network, hardware, and JVM.

When a problem occurs, the ORB can throw an org.omg.CORBA.* exception, some text that describes the reason, a minor code, and a completion status. Before you assume that the ORB is the cause of problem, do the following checks:
  • Check that the scenario can be reproduced in a similar configuration.
  • Check that the JIT is disabled (see Diagnosing a JIT or AOT problem in the J9 VM reference).
  • Disable additional CPUs.
  • Disable Simultaneous Multithreading (SMT) where possible.
  • Eliminate memory dependencies with the client or server. The lack of physical memory can be the cause of slow performance, apparent hangs, or crashes. To remove these problems, ensure that you have a reasonable headroom of memory.
  • Check physical network problems (firewalls, comm links, routers, DNS name servers, and so on). These are the major causes of CORBA COMM_FAILURE exceptions. As a test, ping your own workstation name.
  • If the application is using a database such as DB2®, switch to the most reliable driver. For example, to isolate DB2 AppDriver, switch to Net Driver, which is slower and uses sockets, but is more reliable.