[mythtv-users] mythbackend crashes

[Stephen Worthington]

On Sun, 26 Jun 2022 20:41:35 -0400, you wrote:

>Hello,
>I am getting repeated crashes with mythbackend lately - a log is below. I
>am on .31 on Fedora.  It looks like myth is trying to delete a file that
>doesn't exist.  Can someone help me with the steps to fix this?  I
>sometimes mark files for deletion from a leanfront frontend; I'm not sure
>if I created problem by doing that.  TIA.
>
>2022-06-26 10:13:29.168689 E [374213/374213] CoreContext
>mainserver.cpp:3147 (DoHandleDeleteRecording) - MainServer: ERROR when
>trying to delete file:
>GetPlaybackURL/UNABLE/TO/FIND/LOCAL/FILE/ON/mythbox/16817_20210813180000.ts.
>File doesn't exist.  Database metadata will not be removed.
>2022-06-26 10:15:06.436577 N [374213/374252] Scheduler scheduler.cpp:3303
>(CheckShutdownServer) - CheckShutdownServer returned - Not OK to shutdown
>2022-06-26 10:16:08.742608 I [374213/374213] CoreContext
>housekeeper.cpp:738 (Run) - Queueing HouseKeeperTask 'HardwareProfiler'.
>2022-06-26 10:16:08.742710 I [374213/374402] HouseKeeping mythdbcon.cpp:423
>(PurgeIdleConnections) - New DB connection, total: 10
>2022-06-26 10:16:08.743973 I [374213/374402] HouseKeeping
>housekeeper.cpp:139 (Run) - Running HouseKeeperTask 'HardwareProfiler'.
>2022-06-26 10:16:08.748636 I [374213/374402] HouseKeeping
>housekeeper.cpp:154 (Run) - HouseKeeperTask 'HardwareProfiler' Failed.
>2022-06-26 10:16:42.751186 I [374213/374252] Scheduler scheduler.cpp:2330
>(HandleReschedule) - Reschedule requested for MATCH 0 1 1
>2022-06-26T23:30:00Z EITScanner
>2022-06-26 10:16:42.772305 I [374213/374252] Scheduler scheduler.cpp:2444
>(HandleReschedule) - Scheduled 57 items in 0.0 = 0.01 match + 0.00 check +
>0.01 place
>2022-06-26 10:16:42.866021 I [374213/374242] TVRecEvent tv_rec.cpp:3600
>(TuningFrequency) - TVRec[12]: TuningFrequency
>2022-06-26 10:16:42.882395 I [374213/374242] TVRecEvent
>recorders/hdhrstreamhandler.cpp:393 (Connect) - HDHRSH[12](1017D735): Added
>2 devices from 1017D735
>2022-06-26 10:16:42.900487 I [374213/374242] TVRecEvent
>recorders/hdhrstreamhandler.cpp:410 (Connect) - HDHRSH[12](1017D735):
>Connected to device(1017D735-0)
>2022-06-26 10:17:20.003006 C [374213/374213] CoreContext
>signalhandling.cpp:294 (handleSignal) - Received Aborted: Code -6, PID
>374213, UID 1001, Value 0x00000000

The message about the missing file is happening seconds before the
crash happens, so it is not the problem.  Missing files are well
handled by MythTV and do not cause any problems, but you will keep
getting messages like this until you delete the database entry for the
recording that has the missing file.  To find the recording, you can
do a MySQL query:

sudo mysql
select * from recorded where basename='16817_20210813180000.ts'\G
exit

Then you should be able to find that recording in your recordings list
and will see that it is marked with an X icon to say its recording
file is missing.  You can then delete that recording from the list.

The last tuner message "Connected to device" is also half a second
before the crash, so the problem may not be related to that either.
The actual crash is from handleSignal which is receiving a signal
telling mythbackend to abort.  I think that the "Code -6" means it has
received a signal 6 from somewhere, and signal 6 is SIGABRT, which
usually is caused by a call to "abort()" from a piece of code
somewhere.  You may need to collect a backtrace next time it happens
so that you can find out exactly where it is coming from.  See:

https://www.mythtv.org/wiki/Debugging

SIGABRT can also be caused externally by doing a "kill -6" or "kill
-SIGABRT" command.