[mythtv-users] X-Factor Scheduling Snafu

Michael T. Dean mtdean at thirdcontact.com
Thu Oct 20 01:11:42 UTC 2011

On 10/19/2011 11:59 AM, Brian J. Murrell wrote:
> On 11-10-19 11:48 AM, Roger Horner wrote:
>> Since --dd-grab-all first deletes all your schedule data, if it starts just before you are about to record a program, wouldn't it cause you to miss the first 2 minutes of your program (assuming it takes 2 minutes to run as Kris B. says) since without schedule data your BE no longer knows to record it?
> Hrm.  Is this really true?  This seems like a good case for building the
> new schedule before deleting the old one and keeping the "no schedule"
> time/lock to a very minimum while the already-built, new schedule is
> simply swapped in and the old one swapped out.

The only "potential danger" time comes between:

2011-10-18 06:05:46.852 Clearing data for source.


2011-10-18 06:05:56.909 Program table update complete.

in your mythfilldatabase log file.  That is the period during which you 
may be missing listings data for now.  My mythfilldatabase runs with 
--dd-grab-all take a total of 60s, and (as you can see, above,) only 10 
seconds are in the "potential danger" period.  So, for a user with a 
2-minute mfdb run time, I'm guessing that the "potential danger" window 
is much shorter than 2 minutes.

With a 10s "potential danger" window, --dd-grab-all isn't a concern to 
me (and has many times saved recordings due to last-minute schedule 
changes on the day of airing and has never caused any problems for me 
since I started using --dd-grab-all on August 31, 2010 ( 
http://www.gossamer-threads.com/lists/mythtv/users/449426#449426 )).  
This isn't to say it shouldn't be a concern to anyone--each user must 
decide whether or not they trust it enough to run with it.

In truth, during that "potential danger" period--due to the way 
mythfiilldatabase works, I'm estimating I actually have only a 5s window 
of actual danger.  Use the entire "potential danger" period for the 
conservative estimate or about half to three-fourths of it for the 
aggressive estimate (where 3/4 is more appropriate portion for much 
larger "potential danger" windows).


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