<div dir="ltr">Hello,<div><br></div><div>except for NFS, client will synchronously writes to each replica all time. They are also getting meta data from both.</div><div><br></div><div>As it's synchronous, it's going as slower as slowest replica. replica with 2 nodes won't be useful as it's the slowest one that is important.</div></div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature">Cordialement,<br>Mathieu CHATEAU<br><a href="http://www.lotp.fr" target="_blank">http://www.lotp.fr</a></div></div>
<br><div class="gmail_quote">2015-11-23 9:26 GMT+01:00 Tom Farrar <span dir="ltr"><<a href="mailto:tom.farrar86@gmail.com" target="_blank">tom.farrar86@gmail.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_default"><font face="tahoma, sans-serif">Good Morning All,</font></div><div class="gmail_default"><font face="tahoma, sans-serif"><br></font></div><div class="gmail_default"><font face="tahoma, sans-serif">I'm looking at deploying 3 Gluster nodes, two in one location and the third in another. The link between these two locations is fast and fairly low latency, around ~4ms. The volumes are all low write/high read with the largest being a few TBs (with lots of small files). While the primary location will have two nodes in, the secondary location (with one node) will see local reads and writes.</font></div><div class="gmail_default"><font face="tahoma, sans-serif"><br></font></div><div class="gmail_default"><font face="tahoma, sans-serif">I'm a little concerned about running the replication in separate locations given that from what I've read Gluster doesn't like latency. Is this a valid concern? I've seen a few options for what I believe is keeping reads local so they don't go to the distant node, but I'm struggling to find a definitive answer (</font><span style="color:rgb(0,0,0);white-space:pre-wrap"><font face="monospace, monospace">cluster.read-subvolume</font><font face="tahoma, sans-serif"> perhaps)</font></span><font face="tahoma, sans-serif">.</font></div><div class="gmail_default"><font face="tahoma, sans-serif"><br></font></div><div class="gmail_default"><font face="tahoma, sans-serif">Also, in terms of configuration for low write/high read and a large volume of small files, the following seems to be the recommended from what I can cobble together - does this seem ok?</font></div><div class="gmail_default" style="font-family:tahoma,sans-serif"><br></div><div class="gmail_default"><div class="gmail_default"><font face="monospace, monospace">Options Reconfigured:</font></div><div class="gmail_default"><font face="monospace, monospace">performance.readdir-ahead: on</font></div><div class="gmail_default"><font face="monospace, monospace">cluster.ensure-durability: off</font></div><div class="gmail_default"><font face="monospace, monospace">server.event-threads: 4</font></div><div class="gmail_default"><font face="monospace, monospace">cluster.lookup-optimize: on</font></div><div class="gmail_default"><font face="monospace, monospace">performance.quick-read: on</font></div><div class="gmail_default"><font face="monospace, monospace">cluster.readdir-optimize: on</font></div><div class="gmail_default"><font face="monospace, monospace"><br></font></div><div class="gmail_default"><font face="tahoma, sans-serif">Many thanks,</font></div><div class="gmail_default"><font face="tahoma, sans-serif"><br></font></div><div class="gmail_default"><font face="tahoma, sans-serif">Tom</font></div></div>
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