[mythtv-users] Multi frontend question

[Bruce Markey]

Rob Booth wrote:
> I've got a question based on this setup.
> 
> 1 backend server with 2 or more tuner cards.
> 2 or more frontends.
> 
> Now lets say the frontend 1 is watching live tv on tuner 1, what is in 
> place to stop frontend 2 from changing the channel that tuner 1 is 
> currently tuned to?

If frontend 2 went to Live TV, it would be assigned to tuner 2.
There is no sharing of tuneers for Live TV. Frontend 3 would
get a message saying that there is no tuner available.

> What about frontend 1 watching  a recorded show, and frontend 2 wanting 
> to watch the same show but at a different place in the recording.  I'm 
> assuming that this isn't a problem since the file exists and could 
> easily be served to both frontends.

Two different processes reading from different places in the
file. Not a problem. If both users decided to "save and exit",
the later bookmark would overwrite the earlier one. 
 
> But given the above scenario, what if frontend 1 decides to delete the 
> show when they are finished watching it, but frontend 2 is still 
> watching the show?  Would the show be marked to be deleted?  Would the 
> user on frontend 1 be denied?

This is basic Unix and not specific to MythTV. When a file is
deleted, the unlink reduces the link count by one. The inodes
and blocks are not cleared if a process still has the file open.
Therefore 2 can continue to watch until she exits. At that
point the file is closed and it's gone. The mysql "recorded"
table entry would have been deleted when 1 chose to delete.

--  bjm