[mythtv-users] scheduler doesn't run ?

[Per Jessen]

Michael T. Dean wrote:

> On 01/14/2016 03:04 AM, Per Jessen wrote:
>> Michael T. Dean wrote:
>>
>> I'm slowly getting the feeling it's somehow related to these messages:
>>
>> Scheduled 629 items in 1764.2 = 1752.96 match + 11.25 place
>> Scheduled 643 items in 164.1 = 155.02 match + 9.06 place
>> Scheduled 643 items in 916.3 = 904.87 match + 11.45 place
>>
>> Judging by the code, this is about how much was scheduled and how long
>> it took.  I took a look at those messages in the logs (back to 31/10, I
>> only keep the logs for so long).
>>
>> http://files.jessen.ch/mythtv-items-scheduled-since-20151031a.jpeg
>>
>> It seems to have been fairly steady, with a rise since December. It's
>> gone from around 600 items to more than 800.
>>
>> This is the interesting one though:
>> http://files.jessen.ch/mythtv-time-to-schedule-since-20151031a.jpeg
>>
>> Very stable until last week of November, then mayhem as of December.
>>
>> It looks like it used to take 60 seconds, since December up to an hour
>> or more - if it takes too long to run a reschedule, might this upset
>> the overall scheduling?
> 
> Yep.  That's your problem.  It's not that scheduling isn't running, it's
> that it's taking so long to run that you're not noticing the changes.
> 
> Reschedules should take (significantly) less than a minute on a properly
> tuned system, though things should generally work fine with them taking
> up to a minute or so (some people run with scheduling taking multiple
> minutes, though, it's not really designed/tested for such slow
> response). 

60-80 seconds is what I used to have in late November. 

> As far as the MythTV side of things go, there are exactly 3 things that
> determine scheduling time:  
> 1) number of programs to consider for
> scheduling (which, generally, is related to number of channels), 
> 2) number of recording rules, and 
> 3) number of previous recordings. 
> So, did any of those things change in November/December? 

I hadn't done a channel rescan for quite some time, so (1) is likely to have 
changed when I did so around then.  (2) is around 440, doesn't change that 
much. (3) grows every day of course, but slowly.

> Did you add new tuners (or virtual tuners) or new sources or reconfigure
> your sources or ...?

Nope, didn't change the hardware, it's been the same for at least 2 years. 
(except for recording space).

> If so, you may need to pare down one of the 3--i.e. delete unnecessary
> channels (in mythtv-setup's Channel Editor), recording rules (in Manage
> Recordings|Recording Rules), or recording history (in Manage
> Recordings|Previously Recorded). 

There's plenty of unnecessary channels, thousands. I could delete some, but 
they'll come right back on the next channel scan :-(

> If none of the above changed in November/December, then it's unlikely to
> be something that you can fix in MythTV.  Instead, it's most likely some
> big change to your configuration (i.e. change of file system on which
> the MySQL data/temp storage lives or change of MySQL configuration--such
> as database Storage Engine--or similar). 

Nothing like that was changed - the last thing I changed was add some more 
space for recordings, the base systems have remained the same since I 
installed them around three years ago. (okay, a few software updates and 
such).

> (Did your distro change the file system used for /tmp?  Is it an actual
> file system or a in-memory file system--where in-memory file system will
> defeat the purpose of using it for a MySQL scratch file system for things
> that won't fit in memory.) 

Both /tmp and /var/tmp are on real iron. 

> Alternatively, it could be down to issues with your MySQL data
> storage (i.e. you need to run optimize_mythdb.pl or similar).

This morning I did an optimize of "recordedseek" (millions of rows) which 
seems to have improved things.  I'll report back later.  

> Since your scheduling time didn't grow slowly, it's almost definitely
> not just a problem of "normal" growth of recording rules/history.  The
> large, sudden growth in November/December indicates a big change to
> something around that time. 

I'm pretty certain all I did was rescan all the DVB-S2? transponders. 



/Per