[mythtv-commits] Ticket #6516: Mythfilldatabase times out when rescheduling

[MythTV]

#6516: Mythfilldatabase times out when rescheduling
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 Reporter:  Joel <mythtv at ebel.mybox.org>  |       Owner:  ijr       
     Type:  defect                        |      Status:  new       
 Priority:  minor                         |   Milestone:  unknown   
Component:  MythTV - General              |     Version:  0.21-fixes
 Severity:  medium                        |     Mlocked:  0         
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 The visible problem is that my recording schedules aren't getting updated
 when mythfilldatabase runs.  This is because the socket on which
 mythfilldatabase requests the reschedule is timing out waiting for
 mythbackend to respond.  I believe the reason for this is that mythbackend
 is blocking on various responses to mysql queries it has made, and mysql
 is running slowly, unable to respond within the socket timeout of 7
 seconds, as a result of the load put on it by the recently finished
 mythfilldatabase run.

 I have tried to make the database faster by increasing it's limits in
 my.cnf, but it still seems that fastest it can complete the requests is
 around 15 seconds.  I don't know why the database is slow, but mythtv
 should be able to work around this.  I've temporarily increased the quick
 timeout to 30 seconds (matching the long timeout) by editing
 mythsocket.cpp, and that works for me, but there's probably a better
 solution.  I propose one or both of the following:

 1.  Increase the timout or retries that mythfilldatbase uses.  It could be
 told to simply not use the quick timeout, and that would work for me.  It
 retries once currently, but a second and third would also give it enough
 time to let the database catch up with itself.

 2.  Figure out why mythtv is blocking on mysql for this.  I don't see any
 reason that mythbackend should be capable of accepting and queuing a
 reschedule request even if mysql is being slow to respond.  Maybe there is
 a good reason I'm unaware of though.

 I realize it would be easy to say it's the databases fault, rather than
 mythtv's, but I think there are some simple ways to work around this,
 which would improve the user experience for those with slow databases.
 This seems to be a recurring problem for many users.

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Ticket URL: <http://svn.mythtv.org/trac/ticket/6516>
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