[mythtv-users] SBE's mythjobqueue preventing MBE idleness

[Michael T. Dean]

On 04/28/2011 09:57 AM, Brian J. Murrell wrote:
> Per another thread, I have stopped the mythbackend process on my
> tuner-less SBE (it's only supposed to lend it's CPU cycles to
> commflagging) since it's an unsupported configuration and instead
> started mythjobqueue (with -v most for interest's sake).
>
> The problem is that it seems to be keeping the MBE from going into
> idle-shutdown (i.e. suspend) mode.  Since starting mythjobqueue my
> backend has not gone into idle mode yet within less than a second of
> stopping mythjobqueue it started it's idle processing:
>
> On the SBE:
>
> 2011-04-28 09:51:14.975 JobQueue: GetJobsInQueue: Ignore 'Flag
> Commercials' Job for chanid 1045 @ 20110428073000 in Finished state.
> ^C
>
> On the MBE:
>
> 2011-04-28 09:51:41.316 I'm idle now... shutdown will occur in 300 seconds.
>
> Yes, the MBE's timestamp is .6 of a second earlier than the SBE.  Well
> within the margin of error for this network AFAIC.
>
> Is this a known limitation of mythjobqueue?

 From my perspective, it is now a known limitation of 
mythjobqueue--before it was just a limitation of mythjobqueue.  Thanks 
for noticing.  This is something that needs reworking before 0.25.

In the meantime, we might be able to do some workarounds.  The one I 
think is probably the best/safest is to write a script that can be 
called on a loop (either the script that starts (and backgrounds) 
mythjobqueue, or in a cron job or whatever), and checks to see if the 
jobqueue host is currently processing any jobs (and/or whether any jobs 
are left to process).  If not, it can kill the mythjobqueue process--and 
could also shut down the job queue host, if you want.

The best way to check would be to use the Python bindings' Job class to 
get the status and hostname attributes.  If the status is Job.RUNNING 
and the hostname is the mythjobqueue (current) hostname, then it's not 
safe to kill mythjobqueue/shut down the job queue host.


http://www.mythtv.org/wiki/0.24_Python_Bindings

If no one else does it before, I'll try to get a chance to look into 
this over the weekend.

Mike