<div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Jun 21, 2018 at 10:24 AM, Raghavendra Gowdappa <span dir="ltr"><<a href="mailto:rgowdapp@redhat.com" target="_blank">rgowdapp@redhat.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div><div><div><div><div>For the case of writes to glusterfs mount,<br><br></div>I saw in earlier conversations that there are too many lookups, but small number of writes. Since writes cached in write-behind would invalidate metadata cache, lookups won't be absorbed by md-cache. I am wondering what would results look like if we turn off performance.write-behind.<br><br></div>@Pat,<br><br></div>Can you set,<br><br></div># gluster volume set <volname> performance.write-behind off<br></div></div></div></div></blockquote><div><br></div><div>Please turn on "group metadata-cache" for write tests too.</div><div> <br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div><br></div>and redo the tests writing to glusterfs mount? Let us know about the results you see.<br><br></div>regards,<br></div>Raghavendra<br></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Jun 21, 2018 at 8:33 AM, Raghavendra Gowdappa <span dir="ltr"><<a href="mailto:rgowdapp@redhat.com" target="_blank">rgowdapp@redhat.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote"><span>On Thu, Jun 21, 2018 at 8:32 AM, Raghavendra Gowdappa <span dir="ltr"><<a href="mailto:rgowdapp@redhat.com" target="_blank">rgowdapp@redhat.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div><div>For the case of reading from Glusterfs mount, read-ahead should help. However, we've known issues with read-ahead[1][2]. To work around these, can you try with,<br><br></div>1. Turn off performance.open-behind<br></div>#gluster volume set <volname> performance.open-behind off<br><br><div>2. enable group meta metadata-cache<br>
# gluster volume set <volname> group metadata-cache</div></div></blockquote><div><br></div></span><div>[1] <a href="https://bugzilla.redhat.com/show_bug.cgi?id=1084508" target="_blank">https://bugzilla.redhat.com/sh<wbr>ow_bug.cgi?id=1084508</a></div><div>[2] <a href="https://bugzilla.redhat.com/show_bug.cgi?id=1214489" target="_blank">https://bugzilla.redhat.com/sh<wbr>ow_bug.cgi?id=1214489</a></div><span><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div><div><div class="m_-7085830777103976589m_-1104802400275053683gmail-m_5499637752699686457h5"><br><br><div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Jun 21, 2018 at 5:00 AM, Pat Haley <span dir="ltr"><<a href="mailto:phaley@mit.edu" target="_blank">phaley@mit.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br>
Hi,<br>
<br>
We were recently revisiting our problems with the slowness of gluster writes (<a href="http://lists.gluster.org/pipermail/gluster-users/2017-April/030529.html" rel="noreferrer" target="_blank">http://lists.gluster.org/pipe<wbr>rmail/gluster-users/2017-April<wbr>/030529.html</a>). Specifically we were testing the suggestions in a recent post (<a href="http://lists.gluster.org/pipermail/gluster-users/2018-March/033699.html" rel="noreferrer" target="_blank">http://lists.gluster.org/pipe<wbr>rmail/gluster-users/2018-March<wbr>/033699.html</a>). The first two suggestions (specifying a negative-timeout in the mount settings or adding rpc-auth-allow-insecure to glusterd.vol) did not improve our performance, while setting "disperse.eager-lock off" provided a tiny (5%) speed-up.<br>
<br>
Some of the various tests we have tried earlier can be seen in the links below. Do any of the above observations suggest what we could try next to either improve the speed or debug the issue? Thanks<br>
<br>
<a href="http://lists.gluster.org/pipermail/gluster-users/2017-June/031565.html" rel="noreferrer" target="_blank">http://lists.gluster.org/piper<wbr>mail/gluster-users/2017-June/0<wbr>31565.html</a><br>
<a href="http://lists.gluster.org/pipermail/gluster-users/2017-May/030937.html" rel="noreferrer" target="_blank">http://lists.gluster.org/piper<wbr>mail/gluster-users/2017-May/03<wbr>0937.html</a><br>
<br>
Pat<br>
<br>
-- <br>
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Pat Haley Email: <a href="mailto:phaley@mit.edu" target="_blank">phaley@mit.edu</a><br>
Center for Ocean Engineering Phone: (617) 253-6824<br>
Dept. of Mechanical Engineering Fax: (617) 253-8125<br>
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