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<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">Good day to you Pranith,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">Thank you for your answer, it was exactly this. However, we still have an issue with RELATIME on GlusterFS.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">Stating the file does not modify atime anymore, with quick-read disabled, however cat-ing the file does not replicate the atime.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">If I touch manually the file, the atime (or utimes) is replicated correctly.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">So to sum it up:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l1 level1 lfo5"><![if !supportLists]><span lang="EN-US" style="font-family:Symbol;color:#1F497D"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="EN-US" style="color:#1F497D">[node1] Touch –a file1
<o:p></o:p></span></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l1 level2 lfo5">
<![if !supportLists]><span lang="EN-US" style="font-family:"Courier New";color:#1F497D"><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="EN-US" style="font-family:Wingdings;color:#1F497D">à</span><span lang="EN-US" style="color:#1F497D"> Access time is right on [node1] [node2] and [node3]<o:p></o:p></span></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l1 level1 lfo5"><![if !supportLists]><span lang="EN-US" style="font-family:Symbol;color:#1F497D"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="EN-US" style="color:#1F497D">[node1] Cat file1
<o:p></o:p></span></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l1 level2 lfo5">
<![if !supportLists]><span lang="EN-US" style="font-family:"Courier New";color:#1F497D"><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="EN-US" style="font-family:Wingdings;color:#1F497D">à</span><span lang="EN-US" style="color:#1F497D"> Access time is right on [node1]<o:p></o:p></span></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l1 level2 lfo5">
<![if !supportLists]><span lang="EN-US" style="font-family:"Courier New";color:#1F497D"><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="EN-US" style="font-family:Wingdings;color:#1F497D">à</span><span lang="EN-US" style="color:#1F497D"> Access time is wrong on [node2] and [node3]<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">Would you have any idea what is going on behind the curtain, and if there is any way to fix that behavior?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">Thank you,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">Simon<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="color:windowtext;mso-fareast-language:FR-CA">From:</span></b><span lang="EN-US" style="color:windowtext;mso-fareast-language:FR-CA"> Pranith Kumar Karampuri [mailto:pkarampu@redhat.com]
<br>
<b>Sent:</b> 5 février 2016 00:55<br>
<b>To:</b> Simon Turcotte-Langevin <simon.turcotte-langevin@ubisoft.com>; gluster-users@gluster.org<br>
<b>Cc:</b> UPS_Development <UPS_Development@ubisoft.com><br>
<b>Subject:</b> Re: [Gluster-users] GlusterFS behaviour on stat syscall with relatime activated<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:12.0pt;mso-fareast-language:FR-CA"><o:p> </o:p></span></p>
<div>
<p class="MsoNormal">On 02/03/2016 10:12 PM, Simon Turcotte-Langevin wrote:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal"><span lang="EN-US">Hi, we have multiple clusters of GlusterFS which are mostly alike. The typical setup is as such:</span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]><span lang="EN-US">Cluster of 3 nodes</span><o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]><span lang="EN-US">Replication factor of 3</span><o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]><span lang="EN-US">Each node has 1 brick, mounted on XFS with RELATIME and NODIRATIME</span><o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]><span lang="EN-US">Each node has 8 disks in RAID 0 hardware</span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US">The main problem we are facing is that observation of the access time of a file on the volume will update the access time.</span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US">The steps to reproduce the problem are:</span><o:p></o:p></p>
<p class="MsoNormal"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l2 level1 lfo4"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]><span lang="EN-US">Create a file (echo ‘some data’ > /mnt/gv0/file)</span><o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l2 level1 lfo4"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]><span lang="EN-US">Touch its mtime and atime to some past date (touch –d 19700101 /mnt/gv0/file)</span><o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l2 level1 lfo4"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]><span lang="EN-US">Touch its mtime to the current timestamp (touch –m /mnt/gv0/file)</span><o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l2 level1 lfo4"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]><span lang="EN-US">Stat the file until atime is updated (stat /mnt/gv0/file)</span><o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:72.0pt;text-indent:-18.0pt;mso-list:l2 level2 lfo4">
<![if !supportLists]><span style="font-family:"Courier New""><span style="mso-list:Ignore">o<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="EN-US">Sometimes it’s instant, sometimes it requires to execute the above command a couple of time</span><o:p></o:p></p>
</blockquote>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif;mso-fareast-language:FR-CA">atime changes on open call.<br>
<br>
Quick-read xlator opens the file and reads the content on 'lookup' which gets triggered in stat. It does that to serve reads from memory to reduce number of network round trips for small files. Could you disable that xlator and try the experiment? On my machine
the time didn't change after I disabled that feature using:<br>
<br>
"gluster volume set <volname> quick-read off"<br>
<br>
Pranith<br>
<br>
<o:p></o:p></span></p>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoListParagraph"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:0cm"><span lang="EN-US">On the IRC channel, I spoke to a developer (nickname ndevos) who said that it might be a getxattr() syscall that could be called when stat() is called on a replicated volume.</span><o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:0cm"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:0cm"><span lang="EN-US">Anybody can reproduce this issue? Is it a bug, or is it working as intended? Is there any workaround?</span><o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:0cm"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:0cm"><span lang="EN-US">Thank you,</span><o:p></o:p></p>
<p class="MsoListParagraph" style="margin-left:0cm"><span lang="EN-US">Simon</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif;mso-fareast-language:FR-CA"><br>
<br>
<br>
<o:p></o:p></span></p>
<pre>_______________________________________________<o:p></o:p></pre>
<pre>Gluster-users mailing list<o:p></o:p></pre>
<pre><a href="mailto:Gluster-users@gluster.org">Gluster-users@gluster.org</a><o:p></o:p></pre>
<pre><a href="http://www.gluster.org/mailman/listinfo/gluster-users">http://www.gluster.org/mailman/listinfo/gluster-users</a><o:p></o:p></pre>
</blockquote>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman",serif;mso-fareast-language:FR-CA"><o:p> </o:p></span></p>
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