[mythtv-users] Getting slower

[Stuart Auchterlonie]

On 19/08/2020 04:46, DaveD wrote:
> On 8/18/20 3:01 PM, Stuart Auchterlonie wrote:
>> Acutally, looking at
>> https://code.mythtv.org/trac/ticket/12307#comment:11
>>
>> we weren't checking to see if the user had disabled
>> the media monitor early enough, so it was still calling
>> out to dbus.
>>
>> I've committed a fix to respect the user setting thereby
>> bypassing this check at startup, and backported it to
>> fixes/31. This should be in updated packages in the next
>> 24hrs or so.
>>
>>
>> Regards
>> Stuart
> 
> This is very encouraging.  I hope you have it figured out.  That said, I
> don't know enough about dbus to fit your model into my experience.
> 
> I use a firewire to a cable box and that firewire interface is extremely
> fragile.  If the cable box gets turned off (remote in wrong mode!), I
> have to reboot to get mythbackend to get it's connection back where it
> can change channels again.  Some times I can pull and re-plug the
> firewire cable and restart mythbackend, sometimes I just need to restart
> mythbackend, sometimes I can unload the firewire module and re-modprobe
> it, etc, etc.  But I digress.
> 
> A week or so ago, I had to both turn off the power to my computer and
> unplug the cable box then fire it back up to re-establish the
> connection.  After that, mythfrontend started up every day with no
> delay; < 10 seconds from hitting the key on the remote to recordings
> list.  Every time.  Until it didn't.  No idea what changed to make it
> sluggish again, but it takes > 50 seconds, now.
> 
> What you said about dbus timing out the first time and not later does
> not quite fit the experience of it working, time after time, and then
> inexplicably stop working.  I'm wondering if there's something else I
> did to get the dbus daemon into a different state?  I think I'll try
> rebooting and get it working reliably again, then pay close attention to
> what I do to see if I can figure out what makes it change.
> 
> As I wrote this, it occurred to me that maybe the problem is the
> firewire connection being broken so I started mythfrontend, waiting
> nearly a minute for it to start, and then tried tuning a cable channel
> and, indeed, the connection had been lost.  After restarting
> mythbackend, the connection was re-established and mythfrontend started
> up normally.
> 
> So, it seems I have discovered the problem.  I don't understand why the
> lack of a connection of the backend to a cable box ("tuner") causes a
> slow startup of the frontend, but it seems that it certainly does.  It's
> actually a good thing as now I know that if it starts up slow, I need to
> restart the backend (at least) so it will be ready when needed (I have
> lost recordings due to the lack of connection).
> 
> It seems my  problem was not related to dbus nor was it related to media
> monitoring.  Others with slow startup will likely not be helped by my
> discovery, but it seems all hardware connections should be suspect.
> 
> If anyone knows of some way to programmatically check the firewire
> connection and, ideally, re-establish it programmatically, I would love
> to hear it.
> 

There are 2 different problems here.

1) slow frontend startup due to DBus requests for the UDisks service.
2) your firewire issues with the backend described above

My fix will address #1, but has nothing todo with #2

Firewire communication between the backend and the STB does not use
DBus at all.


Regards
Stuart