Home / server / Questions / 313915
Accepted
Ramon Tayag
Asked: 2011-09-22 05:47:26 +0800 CST

Watching ImageMagick and killing when they run too long

  • 772

I use a program that calls ImageMagick's command-line commands. These are supposed to run instantly -- perhaps 1 or 2 seconds. However, lately I've noticed a bunch of them got stuck.

Frozen processes

I use monit to monitor the server and watch certain things when the memory goes overboard. What would be a good way to watch ImageMagick? I'd like to kill the processes if they've been alive for 1 minute. However, I don't want to do a blanket kill all convert processes.

What do I do?

Thanks!

monitoring imagemagick

3 Answers

  1. Best Answer

    You can parse the output of ps -ef (or ps -axf on BSDish systems) to find processes with a start time (STIME) greater than X, or you can use TIME (CPU seconds used).

    Implementation of this solution is left as an exercise for the reader, it's relatively simple. Hints:

    • You can do it with a shell script (for line in top; do ... done)
    • grep and awk (or cut) are your friends
    • STIME changes format depending on how long the process has been running.
      If we're talking within a 24 hour period you shouldn't have to worry about that, and you can kill any process that doesn't match the expected format for something started <24 hours ago.
    • Test your script first (echo "I want to kill $PID ($line)") before you let it really shoot processes in the head!
    • 3

  2. Is it possible to modify the way ImageMagick is called? Setting limits with ulimit/limit before execing ImageMagick would allow you to set the CPU seconds and the kernel will take care of it for you.

    http://www.cims.nyu.edu/cgi-comment/man.cgi?section=1&topic=limit

    • 0
    • 0