[mythtv-users] Slave Backend requirements

[Michael Watson]

On 21/08/2013 9:22 AM, Doug Scoular (dscoular) wrote:
> Hi,
> In the midst of all this discussion on low powered systems (arm et 
> al)… I was wondering what requirements a Slave Backend might have.
>
> 1) Does the Slave Backend merely present tuner cards to the Master 
> Backend's scheduler or does it do some hard work of it's own ?
Slave backend can do Transcoding, Commercial Detecting, Metadata 
lookups, (or any user jobs provided it has the binary/scripts to perform 
the user jobs, and access to the storage volumes if required - 
conversion to mkv/mp4 as an example)

>
> 2) Can a powerful Master Backend access the Slave Backend's storage 
> groups and run the commercial detection and/or user jobs instead of 
> the Slave ?
Yes, but you will need to configure NFS (or some other file sharing), 
preferably via automount.
>
> I'm wondering if a simpler, more appropriate role for low powered 
> systems might be to present more tuners to a powerful Master Backend. 
> Maybe that is not what a Slave Backend offers or maybe a low end 
> system could be made to present tuners a bit like an HDHomeRun or 
> PopcornHour does. Any thoughts or explanations much appreciated.
>
> Righto, I'm pulling my flame retardant, drinking trousers on now… 
> flame on!
>
> Cheers,
>
> Doug
>
I run my Frontends as SBE (with a configured Dummy Tuner) to assist with 
commercial detection, whilst I know I can use mythjobqueue to achieve 
this, with Mythjobqueue the SBE/Frontend will not shut down whilst not 
in use, mythjobqueue is great for a 24x7 system.

I also run a SBE with a couple of PCI Tuners, because the MBE has no PCI 
slots free (as I haven't yet replaced them with USB Units). This machine 
is powered up and down by the MBE when its tuners are required for 
recording, it also assists with commercial detection and user jobs 
whilst powered on.

This setup has worked splendidly until 0.27, where currently the SBE 
will cause the MBE to segfault randomly, (almost everytime a SBE is 
started, the MBE will segfault, and other times when the SBE queries for 
any jobs in the queue)