[mythtv] FW: Ticket #10541: SIGSEGV when EIT updating DB and channel change

[Angela]

>> This is MAGIC, wrote 2180 EIT messages within one second, 350 EIT 
>> messages also in one second and 4000 EIT messages within 2 seconds.
>> 
>> I always use InnoDB, having nobarrier should be save for MySQL I 
>> think, in case electricity fails. Losing parts of a recording does not 
>> matter. Any other thoughts ?
>
>You can lose data consistency with nobarrier on power loss, especially with
ext4. As I understand it you will mostly lose data on expanding files, so
database files are fairly safe. However, MythTV should work with barriers
enabled, I >just want to see if your lockups go away after a week running
this way. If that is the case I know to look at how we handle the DB in EIT
scanning vs looking for the problem elsewhere.

Adding nobarrier to mount the ext4 FS where the MySQL DB is located fixed
the delay writing to the DB from up to 2 minutes to less than one second. 

I had 8 events where the fix showed it works fine and doesn't crash
mythbackend anymore. Thanks Daniel. 

When I had the long DB delays, it was still strange that recordings started
after finishing the EIT DB writing or even got cancelled. This shouldn't be
weighted to high, as I got the DB writing delay fixed. 

Hope to see the patch in fixes/0.25. 
Angela