[mythtv-users] Guide updates for CBS and TNT this evening

Michael T. Dean mtdean at thirdcontact.com
Wed Nov 18 19:29:03 UTC 2015


On 11/18/2015 11:59 AM, Robert Eden wrote:
> On 11/18/2015 7:49 AM, Michael T. Dean wrote:
>> So, I would say that the 2am spike is due to people/distros 
>> misconfiguring systems and disabling "Automatically update program 
>> listings" and scheduling a cron job to run at 2am.  I don't know if 
>> some (or most? or all?) distros tend to set up their crontabs so that 
>> /etc/cron.daily/ jobs are run at 2am, but if so, perhaps some 
>> distro(s) is throwing a script to run mythfilldatabase (or to run it 
>> if the script thinks it hasn't been run recently--meaning that the 
>> distro doesn't trust mythbackend to do the job right) in 
>> /etc/cron.daily/.  Regardless, since there's no magic 2am time in any 
>> of MythTV, whatever causes the spike is outside of MythTV--at least 
>> outside of https://github.com/MythTV/mythtv/tree/master/mythtv 
>> (meaning some distros may be putting in some 2am hard-coded time in a 
>> patch, but I don't know of any, and don't see any in 
>> https://github.com/MythTV/packaging ).
>
> Has it always been that way?  I seem to remember when the 2am thing 
> first came up, it was fixed, but many folks had old versions.
>
> The user agent strings at 2am UTC are:
>
>     | MythTV v0.27.20140323-1 MythDownloadManager |
>     | MythTV v0.27.20150622-1 MythDownloadManager |
>     | MythTV v0.27.20151025-1 MythDownloadManager |
>     | MythTV v0.27.20131107-1 MythDownloadManager |
>     | MythTV v0.27.20140520-1 MythDownloadManager |
>     | MythTV v0.27.20140719-1 MythDownloadManager |
>     | MythTV v0.27.20141016-1 MythDownloadManager |
>
> Some are fairly recent (I assume compile) dates.
>
> I'll look into contacting a few users to see what I can figure out.

tl;dr version:
What 0.27/0.27-fixes users can do to work around the breakage is simply 
go into mythtv-setup and change "Guide data program execution start" to 
0 and "Guide data program execution end" to 23 on the last screen 
(labeled "Program Schedule Downloading Options" of the General Settings 
section.  For users on all other versions of MythTV, running at the 
suggested time should work.

-----
Details:

OK, so it looks like the scheduler code rewrite that went in with 0.27 
forgot to ignore the specified run window when run at the suggested time 
was enabled.  This was reported by Frank Phillips in 
https://code.mythtv.org/trac/ticket/12101 and fixed with his patch 
(committed by JYA) in 
https://github.com/MythTV/mythtv/commit/ff22b7199e6bf77105d2206a7945c2dd5b06b697 
so that in master the run window is ignored when suggested times are 
enabled.  It seems that patch was never backported to 0.27, so 0.27 is 
broken.

So, that means that users with small run windows (i.e. smaller than the 
default "unlimited"/24-hr run window) whose suggested time occurs 
outside the run window will, instead of running when suggested, run 
mythfilldatabase at the start of the next run window (within 5mins of 
the start).  For those users who have been running their MythTV systems 
since (created their databases with versions) before 0.25 was released 
(or development versions before Jul 19, 2011), the default window was 
set to 2am-5am ( https://github.com/MythTV/mythtv/commit/d915ef7ab3ee 
).  So, since 0.27 is incorrectly using the run window, it seems many 
users are running at the start of their run windows, and based on the 
2am spike, it seems many of those users are users who have been using 
MythTV for a long time--and for whom mythfilldatabase runs were always 
working properly in the past (i.e. those least likely to notice problems).

What 0.27/0.27-fixes users can do to work around the breakage is simply 
go into mythtv-setup and change "Guide data program execution start" to 
0 and "Guide data program execution end" to 23 on the last screen 
(labeled "Program Schedule Downloading Options" of the General Settings 
section.

Ideally, though, someone will backport the fix (that ignores the run 
window when suggested times are enabled) in 
ff22b7199e6bf77105d2206a7945c2dd5b06b697 to 0.27-fixes.

Mike


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