[mythtv-users] mythjobqueue commflagging startup delay?

[Brian J. Murrell]

On 12-02-11 11:28 AM, Raymond Wagner wrote:
> On 2/11/2012 11:00, Brian J. Murrell wrote:
>> I'm running mythjobqueue on another machine to do commflagging and I've
>> noticed what seems to be a delay in processing.  Let me give you an
>> example:
>>
>> 2012-02-11 10:30:22.919551 I  JobQueue: Commercial Detection Starting for "This Old House":"This Old House Barrington Project, Part 2 of 10" recorded from channel 4024 at 2012-02-11T10:30:00
>> 2012-02-11 10:30:25.451068 C  mythcommflag version: master [v0.25pre-4426-g52d2827] www.mythtv.org
>> 2012-02-11 10:40:54.519037 I  Finding Logo
> 
> I believe there is an intentional 10 minute delay when running 
> commercial flagging live behind a recording.

I wonder why?  It kills efficiency.

It means that a bunch of parallel recordings all hammer the disk at the
same time to get the first 10 minutes of the currently running recordings.

Additionally, chances are, depending on how much memory is available to
cache, that the disk blocks are no longer in cache 10 minutes after they
have been written to disk requiring that they be re-read.  Whereas if
commflagging were done as soon as the frames are read/written to disk
chances are pretty good that the commflagger reading them would end up
reading the cached copies and not hitting the disk for them.

Can anyone explain the reasoning behind this 10 minute delay?  It sounds
all around not friendly.

Cheers,
b.

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