[mythtv-users] Backend lockup?

[Adam Biskobing]

I'm having a similar problem to this where about once a day, I'll find
mythbackend eating up 99% of the CPU.  When this happens I get error
messages about connecting to the backend in mythfrontend and mythweb.
Nothing in the log entries for the backend that look suspicious, and the
frontend of course is reporting problems connecting to the backend.  Not
sure what the problem is or even the best way to troubleshoot it.  Would
a backtrace even be helpful for this?

> -----Original Message-----
> From: mythtv-users-bounces at mythtv.org 
> [mailto:mythtv-users-bounces at mythtv.org] On Behalf Of Kent Williams
> Sent: Thursday, February 26, 2004 1:47 AM
> To: Discussion about mythtv
> Subject: [mythtv-users] Backend lockup?
> 
> 
> On two or three occasions now I have encountered a problem 
> where the backend seems to do strange things and doesn't talk 
> to the frontend or mythweb properly.
> 
> Things started normally this morning where I watched live tv 
> for a bit under an hour. After this I left the frontend 
> sitting idle at the main menu during the day until the 
> afternoon when I went to watch live tv again (there were no 
> scheduled recordings during the day). When I went to watch 
> live tv, I got a 'connection to backend server' lost message. 
> Looking at the backend there was no segfault. It just sat 
> there as usual. After a quick restart of the backend, 
> everything was ok again.
> 
> The backend is a P4 1.6 with two Nova-T cards, running Debian 
> unstable on a 2.4 series kernel. The frontend is a P4 2.8 
> which also runs Debian unstable on a 2.4 series kernel.
> 
> The following was shown in a web browser whilst the backend 
> was showing these symptoms:
> 
> --------------------------------------------------------------
> ----------
> --------
> User Notice at /var/www/mythweb/includes/mythbackend.php, 
> line 122: Unexpected response to MYTH_PROTO_VERSION: 
> --------------------------------------------------------------
> ----------
> --------
> 
> --------------------------------------------------------------
> ----------
> --------
> Fatal Error at /var/www/mythweb/includes/mythbackend.php, 
> line 17: Unable to connect to mythbackend, is it running? 
> The system administrator has been notified and the problem 
> will be remedied shortly.
> 
> --------------------------------------------------------------
> ----------
> --------
> 
> The following is from the log on the frontend:
> 
> 2004-02-26 08:07:18 Using protocol version 3
> 2004-02-26 08:07:18 Using protocol version 3
> 2004-02-26 08:07:18 Using protocol version 3
> Input #0, mpeg,from
> 'rbuf://192.168.20.4:6543/mnt/massstore/temp/ringbug5.nuv':
>  Stream #0.0: Video: mpeg2video, 720x576, 25.00 fps
>  Stream #0.1: Audio: mp2, 48000 Hz, stereo, 192 kb/s
> 2004-02-26 08:07:20 Opening OSS audio device '/dev/dsp'. 
> 2004-02-26 08:07:20 Using XV port 52 2004-02-26 08:07:20 
> Changing from None to WatchingLiveTV 2004-02-26 08:35:18 
> prebuffering pause [mpeg2video @ 0x42309998]ac-tex damaged at 
> 22 8 [mpeg2video @ 0x42309998]concealing errors [mped2video @ 
> 0x42309998]Warning MVs not available 2004-02-26 09:01:47 
> Changing from WatchingLiveTV to None 2004-02-26 09:01:47 
> Changing from None to None 2004-02-26 16:28:52 ReadStringList 
> timeout (quick). Connection to backend server lost 2004-02-26 
> 16:28:55 Changing from None to None 2004-02-26 16:29:08 
> Connecting to backend server: 192.168.20.4:6543 (try 1 of 5) 
> 2004-02-26 16:29:16 ReadStringList timeout (quick). 
> 2004-02-26 16:29:16 Unexpected response to 
> MYTH_PROTO_VERSION: 2004-02-26 16:29:16 Changing from None to 
> None Errm, event socket just closed.
> 
> ------------------
> 
> The following is from the log on the backend, notice the 
> absence of a segfault or any other errors:
> 
> Audiostream: Layer: 2  BRate: 192 kb/s  Freq: 48.0 kHz
> Videostream: ASPECT: 16:9  Size = 720x576  FRate: 25 fps  
> BRate: 6.00 Mbit/s
> Audiostream: Layer: 2  BRate: 256 kb/s  Freq: 48.0 kHz
> Videostream: ASPECT: 16:9  Size = 720x576  FRate: 50 fps  
> BRate: 9.00 Mbit/s
> Audiostream: Layer: 2  BRate: 192 kb/s  Freq: 48.0 kHz
> Videostream: ASPECT: 16:9  Size = 720x576  FRate: 25 fps  
> BRate: 6.00 Mbit/s
> Audiostream: Layer: 2  BRate: 192 kb/s  Freq: 48.0 kHz
> Videostream: ASPECT: 16:9  Size = 720x576  FRate: 25 fps  
> BRate: 6.00 Mbit/s
> Audiostream: Layer: 1  BRate: 320 kb/s  Freq: 48.0 kHz
> Videostream: ASPECT: 16:9  Size = 704x576  FRate: 25 fps  
> BRate: 15.00 Mbit/s
> Audiostream: Layer: 2  BRate: 192 kb/s  Freq: 48.0 kHz
> Videostream: ASPECT: 16:9  Size = 720x576  FRate: 25 fps  
> BRate: 6.00 Mbit/s
> Audiostream: Layer: 2  BRate: 256 kb/s  Freq: 48.0 kHz
> Videostream: ASPECT: 16:9  Size = 720x576  FRate: 25 fps  
> BRate: 15.00 Mbit/s
> 
> I'm currently running the backend and frontend with -v all in 
> case it happens again and any more information is revealed.
> 
> Any ideas?
> 
> Cheers,
> Kent
> 
>