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</style></head><body dir="ltr" style="font-size:12pt;color:#000000;background-color:#FFFFFF;font-family:Calibri,Arial,Helvetica,sans-serif;">Do, "gluster volume set help". There is a pretty good explanation of the read subvolume preferences and options. <br><br><div class="gmail_quote">On April 10, 2015 6:56:27 PM PDT, Bharathram Sivasubramanian <Bharathram.Sivasubramanian@vantrix.com> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<p>Thanks, Krutika!<br />
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<p>So, if I understand you correctly...if both Brick 1 and Brick 2 have a good copy of the file, then we can't tell for sure if the file will be read only from Brick 1 all the time and not Brick 2? in other words, for read#1, the file could be read from brick
2 and for another read which could happen a few minutes later, the file could be read from brick 1?<br />
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Krutika Dhananjay <kdhananj@redhat.com><br />
<b>Sent:</b> Friday, April 10, 2015 9:30 PM<br />
<b>To:</b> Bharathram Sivasubramanian<br />
<b>Cc:</b> Gluster-users@gluster.org<br />
<b>Subject:</b> Re: [Gluster-users] Question on file reads from a distributed replicated volume</font>
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<b>From: </b>"Bharathram Sivasubramanian" <Bharathram.Sivasubramanian@vantrix.com><br />
<b>To: </b>Gluster-users@gluster.org<br />
<b>Sent: </b>Saturday, April 11, 2015 3:03:48 AM<br />
<b>Subject: </b>[Gluster-users] Question on file reads from a distributed replicated volume<br />
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<p class="MsoNormal">Let us assume that we have a distributed replicated gluster volume with 4 bricks. Brick 1 is replicating its data with Brick 2 and Brick 3 is replicating its data with Brick 4. Suppose a file called aa.txt is present and replicated on Bricks
1 & 2. A gluster client would like to read this file. Which brick will the file come from? In other words:</p>
<p class="MsoListParagraph" style="text-indent:-18.0pt"><span style="">-<span style="font:7.0pt "Times New Roman"">
</span></span>Will the file always be fetched from brick 1?</p>
<p class="MsoListParagraph" style="text-indent:-18.0pt"><span style="">-<span style="font:7.0pt "Times New Roman"">
</span></span>Will the file always be fetched from brick 2?</p>
<p class="MsoListParagraph" style="text-indent:-18.0pt"><span style="">-<span style="font:7.0pt "Times New Roman"">
</span></span>Will the file be fetched from brick 1 or 2 depending on the attempt? i.e. is there some load balancing where sometimes the file comes from brick 1 and at other times the file will come from brick 2?</p>
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<div>A given file will consistently be "read" from one of the N (in this case 2) replicas, as long as it holds a good copy of the file (that which does not need heal), even with client restart. We call it the "read child" of the file. <span style="font-size:12pt">Load
balancing within a volume is done across different files wherein different files would have different but constant read children.</span></div>
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<div><span style="font-size:12pt">-Krutika</span></div>
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Gluster-users mailing list<br />
Gluster-users@gluster.org<br />
http://www.gluster.org/mailman/listinfo/gluster-users</blockquote>
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<p style="margin-top: 2.5em; margin-bottom: 1em; border-bottom: 1px solid #000"></p><pre class="k9mail"><hr /><br />Gluster-users mailing list<br />Gluster-users@gluster.org<br /><a href="http://www.gluster.org/mailman/listinfo/gluster-users">http://www.gluster.org/mailman/listinfo/gluster-users</a></pre></blockquote></div><br>
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