[mythtv-users] playback issue with mythbackend going cpu bound causing playback issue, and one use local access, another uses myth://
rogerheflin at gmail.com
Fri Jul 1 00:01:50 UTC 2011
I have a separate backend w/2 frontends.
One frontend works fine and does not use remote file transfer, the
other frontend uses remote file transfer when doing playback, on some
videos this causes excessively high network loads and high cpus loads
on the backend (note network is wired Gbit) on some transcoded files
(transcoded to SD) in these cases I can copy back the un-transcoded
1080i original and play it just fine, and it has a much higher bitrate
that the transcoded content that is not working, so something odd is
going on. Also, all of my stuff is trancoded to the same format and
only some transcoded recording have these issues.
What is causing one frontend to use remote file vs local? both
frontends have the storage location mounted via nfs in the exact same
directory as is on the actual backend. One shows
ringbuf(localfilename) the other shows RingBuf(myth://192.168.), so
there has to be something configured for one to use local vs myth:,
but looking through the menus I don't find anything that looks like it
would control this.
And any ideas what is causing the backend behavior? On the same
frontend a working video produces a network rate of about
450Kbyte/second (about right for bitrate), the non-working video
produces an IO rate of about 12.5MByte per second. I have confirmed
that both the frontend and backend are connected with properly working
gigabit, on the bad videos mythbackend on the backend maxes out the
cpu attempting to send out this excessive network traffic, as soon as
the video is stopped the traffic goes away, on the good videos the cpu
usage is reasonable. The other frontend appears to work because it
is not using remote file transfer.
Vidoes play just fine using nfs with mplayer on the frontend having
the issues, I suspect it will play just fine on that frontend if I can
get it to not use remote file transfer bypassing whatever is going on
when the backend server streams the data.
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