djangocrondjango-commands

Run Django command from crontab, only one concurrently

I have a Django commend "script" that i running every 20 second

like this:: (only shows part of it, and works fine ;))

* * * * * /manage.py btupdate
* * * * * sleep 20; /manage.py btupdate
* * * * * sleep 40; /manage.py btupdate

My problem is that the "command script" sometimes may take more than 20 sec. to execute, and I don't want to start another job before the last job has stopped.

How to solve that? ;)

Solution

  • You can use file as indicator of work. (maybe you can use process id too, but solution with file is simple enought)

    1. check if /tmp/iam_working exists
    2. if not exist - create it and run your script ( if exists - do nothing)
    3. remove file after jobs end

    in bash:

    if [ ! -f /tmp/iam_working ] ; then touch /tmp/iam_working; yourcommands; rm /tmp/iam_working; fi