[mythtv] Testers Wanted for New, ON-Deman Input Feature

[Mike Bibbings]

On 26/12/17 16:37, David Engel wrote:
> The "Schedule as Group" feature added last year greatly improved the
> scheduling performance of multirec configurations.  Unfortunately, it
> required the number of simultaneous recordings to be set high enough
> to handle every recording load.  If it was set too low, recordings
> would be missed.  I now have a change ready to address that
> limitation.
>
> Instead of missing recordings, MythTV will now automatically add
> multirec inputs to handle the load.  However, this change adds new
> locking creates the possibility of new deadlocks, especially when the
> added inputs are on slave backends.  Consequently, I'd like for this
> change to get some wider testing before it goes into master.
>
> If you're interested and able to help out on the testing, please
> checkout the devel/scheduler branch and give it a try.  Please post
> any feedback you have here.  If all goes well, I'll commit to master
> in a week or two.
>
> David

David,

I have run some tests over the past two days using a VBOX network tuner 
3442 (firmware XTI_VJ.2.57)  - dual DVB-T/T2 tuners on UK Freeview.

I am using clean install of Xubuntu 16.04, with mythtv (scheduler 
branch) built using default ./configure, all build dependencies 
installed via ansible.

I set multirec to 2 for each tuner, with schedule as a group enabled.

The changes work, with additional tuners being added as required.

However it is possible to overload the VBOX, I have seen its CPU usage 
at 100% and memory usage over 97% with 14 simultaneous recordings (9 on 
one tuner, 5 on the other) .

After the 14 simultaneous recordings, I noticed a problem with the VBOX 
in that LiveTV was timing out on some channels which had previously worked.

I had to reset and reconfigure the VBOX to clear the issue, I presume 
there was some corruption within the VBOX due to overload.

I had previously used this VBOX on my main mythtv system (which runs 
master built from source) for many months with no issues, multrec set to 
5 and no schedule as a group.

So at present, I would not recommend setting multrec above 5 on each 
tuner and schedule as a group should not be used.

Mike