<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<br>
<br>
<div class="moz-cite-prefix">On 02/20/2014 04:56 PM, Jean-Yves
Avenard wrote:<br>
</div>
<blockquote
cite="mid:CANpj82KfWy9_o_6vifBQ=bDRgsDBPWO43YChdk_0Q1Vk8U5Vzg@mail.gmail.com"
type="cite"><br>
<br>
Le vendredi 21 février 2014, Jonas Arndt <<a
moz-do-not-send="true"
href="mailto:jonas.arndt@thearndtfamily.com">jonas.arndt@thearndtfamily.com</a>>
a écrit :<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
<br>
<br>
I actually had a freeze on my system just now. This after having
worked all day. I am on the committed patch on the back-end.
Just rewinding slightly on the front-end, followed by a
pause/play fixed it.<br>
<br>
</blockquote>
<div><br>
</div>
<div>Well, that's a big improvement already, with the previous
bug, it wouldn't have recovered at all.</div>
<div><br>
</div>
<div>But your issue is different here.</div>
<div><br>
</div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
On the backend, just<br>
Feb 20 15:52:03 myth1204 mythbackend: mythbackend[14662]: N
Expire autoexpire.cpp:641 (SendDeleteMessages) Expiring 0 MB for
7653 at 2014-02-20T22:50:42Z => "The Ellen DeGeneres Show"<br>
Feb 20 15:54:03 myth1204 mythbackend: mythbackend[14662]: N
Expire autoexpire.cpp:641 (SendDeleteMessages) Expiring 18 MB
for 7653 at 2014-02-20T22:50:43Z => "The Ellen DeGeneres
Show"<br>
Feb 20 15:54:03 myth1204 mythbackend: mythbackend[14662]: N
Expire autoexpire.cpp:641 (SendDeleteMessages) Expiring 0 MB for
7689 at 2014-02-20T22:51:04Z => "XXII Winter Olympics":Hockey<br>
Feb 20 16:04:03 myth1204 mythbackend: mythbackend[14662]: N
Expire autoexpire.cpp:264 (CalcParams) AutoExpire: CalcParams():
Max required Free Space: 3.0 GB w/freq: 14 min<br>
Feb 20 16:04:03 myth1204 mythbackend: mythbackend[14662]: N
Expire autoexpire.cpp:641 (SendDeleteMessages) Expiring 9983 MB
for 7736 at 2014-02-20T02:03:01Z => "Billy Madison"<br>
Feb 20 16:04:11 myth1204 mythbackend: mythbackend[14662]: W
TFWWrite threadedfilewriter.cpp:545 (DiskLoop)
TFW(/Recordings/7689_20140220225105.mpg:85): write(65424) cnt
131 total 8540088 -- took a long time, 4082 ms<br>
Feb 20 16:04:16 myth1204 mythbackend: mythbackend[14662]: W
TFWWrite threadedfilewriter.cpp:545 (DiskLoop)
TFW(/Recordings/7689_20140220225105.mpg:85): write(65424) cnt
132 total 8503240 -- took a long time, 3919 ms<br>
<br>
Could this be the other issue you were talking about?<br>
<br>
</blockquote>
<div><br>
</div>
<div>No. It's something else. Look at how long it takes for your
backend to write 64kB of data: over 4s each time.</div>
<div>There's no way playback can recover from that, nor anything I
can do about it. Writing is just too slow, it will sooner or
later exhaust the buffer and the frontend as no other choice but
pause.</div>
<div><br>
</div>
<div>Now of course, what the frontend does next is another problem
altogether: it doesn't restart.</div>
<div>But you can't prevent that freeze.</div>
<div><br>
</div>
<div>You see on my system, it never takes more than a few ms to
write 64kB, it may sometimes takes slightly more if the system
finds itself very busy. But 4s, no way.</div>
<div><br>
</div>
<div>You need to look at your hardware here, I'll push soon some
unit tests that stress the disks and give you some some
benchmark about the speed of your disk.</div>
<div><br>
</div>
<div>Also, if there was a problem in myth (which in your
particular case, I doubt) you've truncated your logs way too
much, and it doesn't have the info I would need.</div>
<div>You need to start the backend with -v file --loglevel=debug</div>
<div><br>
</div>
<div>I strongly recommend you modify the threadedfilewriter.cpp
file and comment the two lines I mentioned earlier, otherwise
you'll die under the amount of logs it will spit out.</div>
<div><br>
</div>
If it took a day for the system to experience the issue, that's MB
over MB of logs.
<div><br>
</div>
<div>You need to track what else your backend was doing at the
time, but 8s to write 128kB isn't good</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
</blockquote>
Yeah, all good points.<br>
I have the libmythbase-0.27.so.0.27.0 with the commented out log in
place. I will activate when I get home later to night. In my case I
am running on a VM with direct access to a physical 1TB disk. I am
thinking there could be other reasons why it was slow at writing to
the disk (there are other VMs on the host, but they don't have
access to this disk). I am running sysstat on the VM. The only thing
I could see going on there at this time was a peek in "dentunusd"
(Number of unused cache entries in the directory cache). The peak
was not high though. I have much higher values when the system is
unloaded. I just noted the peak at the exact time when we had the
long writes. On the host there was no changes in resources around
that time (sysstat there as well).<br>
<br>
Thanks,<br>
<br>
// Jonas<br>
</body>
</html>