imagemagick转换CPU错误

Question

I'm running Imagemagick's convert function within a shell script, called via apache/python script. It usually works fine, but now and then the CPU of the server maxes out and does not come back down. Here is the print out of 'top':

PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND           
9672 apache    20   0  357m 1452  640 R 52.9  0.1 223:44.88 convert            
9457 apache    20   0  294m 161m  648 R 47.1  9.8 222:50.15 convert  

What can I do to 1. safeguard against this 2. kill the process? If I do not manually kill the processes, they idle indefinitely, bring the server to a halt.

Answer 1

You have a couple of options but the right answer depends on your particular situation.

You may with to use one of the subprocess commands from Python, and then terminate jobs that are taking too long. If you are just issuing a simple shell command, you might like to see if the "timeout" utility is available for your OS and distribution.

Beyond that you might want to look at decoupling the image processing from your web serving infrastructure.

Finally, it is probably a good idea to post what options your are invoking "convert" with. There may be some folks who know enough to point out obvious problems with your approach with that tool.