1. Qube
2. Qube! Documentation
3. Advanced User's Guide
4. Qube! Job Reference
5. Universal Callbacks

Universal Callbacks

If you ever need to run an external script in a callback, we recommend the use of subprocess.Popen() to run the external script inside the callback. This returns immediately and allows the callback to continue running, rather than blocking and waiting for the external script to complete; otherwise the supervisor process is tied up for the duration of the external script's execution.

Do not use os.system() to run the external script, as this call will block until the external script exits. When a large number of callbacks tie up supervisor processes at the same time, your supervisor performance will suffer.

Do not call sys.exit() at the end of the callback code, this kills the calling supervisor process.

#!/usr/bin/env python

import sys
import qb
import traceback

fh = open('/tmp/univeral_callback_test', 'a')
try:
    # ==================================================
    #  === NOTE: ===
    #  the qb.jobinfo() in callbacks is not the
    #  same as the one in the external python API 
    # ==================================================
    job = qb.jobinfo("-id", qb.jobid())[0]
    fh.write('submitted %(id)s: %(name)s\n' % job)
except:
    fh.write(traceback.format_exc())
fh.close()

sys.exit(0)