Batch processes freezing - shadow processes waiting for "buffer deadlock"

We're got an ORACLE 7.1.4 application runing un a HP 9000 (dual CPU) that performs batch processing of data.

When we run multiple batch processes simultaneously on different data sets (on the same ORACLE instance), we find that all but one of the processes eventually freeze. The remaining process continues performing transactions without any problem.

Eventually a supervisory process times out the frozen batch processes. The oracle shadow processes of these batch processes do not terminate normally. By sending them a SIGQUIT, we get an ORACLE trace file. Examination of this reveals that the shadow process is always waiting on a buffer deadlock.

The point in our application code where the "freeze" occurs varies, as does the time it takes for a batch process to freeze. The "freezing" also appears independent of the data being processed. We've been speaking to ORACLE support for a number of weeks now, without resolving the problem.

I was wondering if anybody else has had similar problems, or (even better) knows of a solution? It may be machine specific (the application runs on RS6000 without problems). It also appears to occur much more readily on SMP boxes.

Thanks,
Michael Harvey
(mgh_at_ausnet.world.net) Received on Sat May 06 1995 - 00:00:00 CEST