[comp.databases] Problem with zombie processes in Oracle on Ultrix3.1

rjh@dnlunx.pttrnl.nl (Heijink R.J.) (04/27/91)

For several weeks we have been struggling with strange problems in
the combination of Oracle PRO*C and the C shell under Ultrix
version 3.1

What happens is the following:

In the PRO*C program we open and close the database.
After closing the database we call csh using the function system.

In this shell we do some trivial things like

set varname= `pwd`

If we repeat this several times, the program hangs at the third
call.

Using the ps command we see that the process that runs pwd is
exiting and has zombie status. Apparently it is not able to find
the parent process, which remains waiting.

We tried many alternatives:

If we use system while the database is open, no zombies occur, but
we always get exitcode -1. 

We tried to save and restore the signals SIGINT, SIGCHLD, SIGPIPE
and SIGCONT. This has no effect.

We tried to replace system by fork/execl/wait. No effect.

Oracle technical support tried to reproduce the problem on a SUN 4
workstation. They were not able to reproduce the problem.

What I like to know:

- Did you encounter similar problems, either on Ultrix systems or
on other systems?

- Do you NOW what causes this problem?

- Do you have any workarounds for this problem?

- Do you have any suggestions for things we may try?

Please send answers to me. I will summarize the results as soon as
we have found a solution and post them to the net.

Rudolf J. Heijink.

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