paulg@smokey.SanDiego.NCR.COM (Paul Gladden) (08/17/90)
We are currently developing a application monitoring daemon.
When the daemon detects various application milestones it takes
an appropriate action. One potential action is to execute a user
supplied shell script. I constructed a two line shell script to
log the execution into a log file. Problem is the shell script
executes for minutes. Several shell scripts executing cause
system performance to nose dive.
The daemon executes the shell script via a fork() and system() function
call. We were prepending the user defined shell from $SHELL into
the system() call
ie. system("-c \"/usr/ucb/csh -c SCRIPT arg1 arg2 arg3 arc4\"");.
I removed the user shell from being passed to the
system() function. This masks the problem, not solving the
root cause.
The shell script:
echo `date` >> test.log
echo "SMFsh: process action.\n Info = \"$*\"\n" >> test.log
The processes in ?error? are preceded by '>'
paulg 665 593 0 11:47:22 ttyx013 1:07 stress -c10000
root 661 1 0 11:46:14 ? 1:03 /etc/sysmond
paulg 769 661 0 11:54:44 ? 0:00 /etc/sysmond
paulg 689 661 0 11:47:53 ? 0:00 /etc/sysmond
paulg 690 689 0 11:47:53 ? 0:00 sh -c /usr/ucb/csh -c "./SMFsh /
> paulg 691 690 1 11:47:53 ? 0:34 /usr/ucb/csh -c ./SMFsh /test/na
paulg 770 769 0 11:54:48 ? 0:00 sh -c /usr/ucb/csh -c "./SMFsh /
> paulg 771 770 0 11:54:49 ? 0:55 /usr/ucb/csh -c ./SMFsh /test/na
paulg 703 661 0 11:48:13 ? 0:00 /etc/sysmond
paulg 704 703 0 11:48:13 ? 0:00 sh -c /usr/ucb/csh -c "./SMFsh /
> paulg 705 704 0 11:48:13 ? 0:53 /usr/ucb/csh -c ./SMFsh /test/na
paulg 734 661 0 11:49:28 ? 0:00 /etc/sysmond
paulg 736 734 0 11:49:28 ? 0:00 sh -c /usr/ucb/csh -c "./SMFsh /
> paulg 737 736 1 11:49:30 ? 2:16 /usr/ucb/csh -c ./SMFsh /test/na
system: MC680020 Unix 5.3
1. What would cause a two line shell to execute for an excessive period of
time?
2. Has anyone encountered this problem before?
Paul Gladden NCR CORPORATION E&M San Diego
paulg@smokey.sandiego.ncr.com 16650 West Bernardo Drive
ucsd!ivory!smokey!paulg San Diego, Ca. 92128
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