[OpenAFS] Re: Client Cache Question
Timothy Balcer
timothy@telmate.com
Tue, 25 Jun 2013 14:03:19 -0700
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Im aware of udp protocol problems.. I've tested network throughput and
responsivity for udp/tcp several different ways, and it's dandy.
Ok I'll do a few straced rsync's and we'll see what happens :)
On Tue, Jun 25, 2013 at 1:59 PM, Andrew Deason <adeason@sinenomine.net>wrote:
> On Tue, 25 Jun 2013 13:49:06 -0700
> Timothy Balcer <timothy@telmate.com> wrote:
>
> > So, this means that there is no networkly or I/O reason on the
> > destination or source that could be the culprit particularly.
>
> That's not necessarily true; even discarding the issues with Rx (the
> transport protocol AFS uses), some networking issues can be UDP-only,
> which would affect AFS but not straight rsync. You may find that very
> unlikely, and I certainly try not to jump straight to that conclusion
> right away, but it has happened before.
>
> > Im running an fstrace right now, but as you said, its very cryptic.
>
> Yeah, I meant that for an fstrace you'd need to give it to an openafs
> developer (give it to me, or to the list, or whatever). That would
> contain filenames and volume names, but not file data.
>
> > Are you suggesting I run an strace on the rsync process? Or that I
> > attach a strace to all the afs background daemons?
>
> Just strace the rsync process. Just to see if we're slow on, say,
> open/write/close, or something you may not expect, like lstat or
> getdents or something. That would also tell you if a specific file is
> slower than all of the others. Before we can look at what it is within
> AFS that's making things so slow, it would help to know what operation
> is actually being slow.
>
> Obviously if you share the raw strace output with someone, that would
> contain path names and a little bit of the file data. I was intending
> for you to look at that and see if anything is unusual, or just report
> what seems "slow".
>
> --
> Andrew Deason
> adeason@sinenomine.net
>
> _______________________________________________
> OpenAFS-info mailing list
> OpenAFS-info@openafs.org
> https://lists.openafs.org/mailman/listinfo/openafs-info
>
--
Timothy Balcer / IT Services
Telmate / San Francisco, CA
Direct / (415) 300-4313
Customer Service / (800) 205-5510
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<div dir=3D"ltr">Im aware of udp protocol problems.. I've tested networ=
k throughput and responsivity for udp/tcp several different ways, and it=
9;s dandy.<br><br>Ok I'll do a few straced rsync's and we'll se=
e what happens :)<br>
</div><div class=3D"gmail_extra"><br><br><div class=3D"gmail_quote">On Tue,=
Jun 25, 2013 at 1:59 PM, Andrew Deason <span dir=3D"ltr"><<a href=3D"ma=
ilto:adeason@sinenomine.net" target=3D"_blank">adeason@sinenomine.net</a>&g=
t;</span> wrote:<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex"><div class=3D"im">On Tue, 25 Jun 2013 13:49:=
06 -0700<br>
Timothy Balcer <<a href=3D"mailto:timothy@telmate.com">timothy@telmate.c=
om</a>> wrote:<br>
<br>
> So, this means that there is no networkly or I/O reason on the<br>
> destination or source that could be the culprit particularly.<br>
<br>
</div>That's not necessarily true; even discarding the issues with Rx (=
the<br>
transport protocol AFS uses), some networking issues can be UDP-only,<br>
which would affect AFS but not straight rsync. You may find that very<br>
unlikely, and I certainly try not to jump straight to that conclusion<br>
right away, but it has happened before.<br>
<div class=3D"im"><br>
> Im running an fstrace right now, but as you said, its very cryptic.<br=
>
<br>
</div>Yeah, I meant that for an fstrace you'd need to give it to an ope=
nafs<br>
developer (give it to me, or to the list, or whatever). That would<br>
contain filenames and volume names, but not file data.<br>
<div class=3D"im"><br>
> Are you suggesting I run an strace on the rsync process? Or that I<br>
> attach a strace to all the afs background daemons?<br>
<br>
</div>Just strace the rsync process. Just to see if we're slow on, say,=
<br>
open/write/close, or something you may not expect, like lstat or<br>
getdents or something. That would also tell you if a specific file is<br>
slower than all of the others. Before we can look at what it is within<br>
AFS that's making things so slow, it would help to know what operation<=
br>
is actually being slow.<br>
<br>
Obviously if you share the raw strace output with someone, that would<br>
contain path names and a little bit of the file data. I was intending<br>
for you to look at that and see if anything is unusual, or just report<br>
what seems "slow".<br>
<div class=3D"HOEnZb"><div class=3D"h5"><br>
--<br>
Andrew Deason<br>
<a href=3D"mailto:adeason@sinenomine.net">adeason@sinenomine.net</a><br>
<br>
_______________________________________________<br>
OpenAFS-info mailing list<br>
<a href=3D"mailto:OpenAFS-info@openafs.org">OpenAFS-info@openafs.org</a><br=
>
<a href=3D"https://lists.openafs.org/mailman/listinfo/openafs-info" target=
=3D"_blank">https://lists.openafs.org/mailman/listinfo/openafs-info</a><br>
</div></div></blockquote></div><br><br clear=3D"all"><br>-- <br><span style=
=3D"border-collapse:collapse;color:rgb(102,102,102);font-family:verdana,san=
s-serif;font-size:x-small">Timothy Balcer / IT Services<br>Telmate / San Fr=
ancisco, CA<br>
Direct / </span><span style=3D"border-collapse:collapse;font-family:verdana=
,sans-serif;font-size:x-small"><font color=3D"#1155cc">(415) 300-4313</font=
><br><font color=3D"#666666">Customer Service /=A0</font><a value=3D"+18002=
055510" style=3D"color:rgb(17,85,204)">(800) 205-5510</a></span>
</div>
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