[mythtv-users] slow mythweb?

[Udo van den Heuvel]

Jens Baumeister wrote:
>> I get this:
>>
>> mysql> show processlist;
(...)
>> (at a time where the backend takes about 60+% and mysql about 30+% of
>> the cpu)
> 
> Okay, that doesn't look like the BUSQ is involved after all, because
> AFAIK it'd be a long-running query that would instantly show up in the
> processlist. 

OK....

(...)

> Considering the extreme nature of your recording schedule, you're
> apprently running into some kind of bottleneck, but I have no idea
> which one.

Jens, thanks for looking into this and helping as you did!


Anybody reading this who can explain what and why?

I have three Power Searches running with either
channel.callsign like "NL1"
or
channel.callsign like "NL2"
or
channel.callsign like "NL3" in the Search Phrase field.

Every now and then mythbackend starts consuming 60+% and mysql 30+% with
about 50% of the CPU being 'nice'.
This lasts for a few minutes as it appears. Mythweb is getting very slow
in this case.
I tuned mysql using the tuning-primer.sh script.
Noticable thing there:
TEMP TABLES
Current tmp_table_size = 384 M
72% of tmp tables created were disk based
Perhaps you should increase your tmp_table_size

The database files are under 30 megs yet the temp is *more* than 10
times(!!) the database?
The size of the tmp_table appears to grow each time. (!?)

# pwd
/var/lib/mysql/mythconverg
# du -sk
24036   .

This is running on a VIA Epia EN12000 with 1GB of RAM and a Terratec
DVB-T card using Fedora 8.
MythTV Version   : exported
MythTV Branch    : trunk
Library API      : 0.22.20080320-2
Network Protocol : 40
QT Version       : 4.3.3
Options compiled in:
 linux release using_oss using_alsa using_backend using_dbox2 using_dvb
using_firewire using_frontend using_hdhomerun using_iptv using_ivtv
using_joystick_menu using_lirc using_opengl_vsync using_v4l using_x11
using_xrandr using_xv using_xvmc using_xvmcw using_xvmc_vld
using_bindings_perl using_bindings_python using_opengl
using_ffmpeg_threads using_libavc_5_3 using_live



Also I filed this ticket http://svn.mythtv.org/trac/ticket/5231 for
mythbackend becoming inresponsive for mythweb after some time.
Dunno if there is a relation.

Anybody can say something about this?