[mythtv-users] Slow scheduling response

Michael T. Dean mtdean at thirdcontact.com
Tue Nov 17 00:59:16 UTC 2009

On 11/16/2009 07:20 PM, Lane Roberts wrote:
> On Mon, Nov 16, 2009 at 1:13 PM, Michael T. Dean wrote:
>> On 11/16/2009 10:51 AM, David Engel wrote:
>>> On Sun, Nov 15, 2009 at 11:28:57AM -0600, Lane Roberts wrote:
>>>> I've got a fresh install of ubuntu 9.10 Server, running myth .22-fixes
>>>> r22824. Performance when adding or changing a recording schedule seems
>>>> extremely slow. In both mythweb and the program guide, saving a change
>>>> results in a 25-30 second wait, where mysqld spikes cpu usage to
>>>> ~100%.
>>>> When I installed, I did migrate recording history and schedules. Am I
>>>> missing an Index on one of the tables? Does anyone else see the same
>>>> thing or have any ideas?
>>> 25-30 second reschedules is not normal.  A missing or corrupted index
>>> could be the cause.  Backup your database and restore it.  If the
>>> problem persists, what does the output look like when you add "-v
>>> schedule" to your mythbackend command line?
>> And, if it is a corrupt schema (meaning missing indices), you may need to do
>> a partial restore.  To do this you'd backup DB, drop DB, create DB with
>> mc.sql, start mythtv-setup to create the schema (including the missing
>> indices), then restore only the non-recreatable data into the new database.
>> http://www.mythtv.org/wiki/Database_Backup_and_Restore#Partial_restore_of_a_backup
>> read the instructions carefully and follow all of the instructions.
> Mike, David,
> Thanks for pointing me in the right direction - there was definitely
> something wrong with the schema. Scheduling is back down to sub-2
> seconds, which is good enough for me.
> The only issue I ran into was that my backup had an `offset` column in
> recordedmarkup, that is not present in the new schema. I truncated the
> partial restore tables, added the `offset` column, and re-ran the
> restore without any problems.

You can only do a partial restore from/to the same version of MythTV 
schema.  If you did a partial restore from your 0.21-fixes database into 
a 0.22-fixes schema, it will corrupt some of your data.  (Most 
noticeable, in this case with seeking in old recordings and with 
bookmarkes, etc.)

If you want to do the partial restore from your 0.21-fixes database, 
you'll need to follow instructions at 
http://www.gossamer-threads.com/lists/mythtv/users/406111#406111 (which 
includes a "blank" 0.21-fixes database--use that instead of start 
mythtv-setup to create the schema).


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