<div dir="ltr"><div><div><div><div><div><div>Sorry for the super-slow response.<br><br></div>The elastic load balancer parses the output of 'qhost' on the cluster:<br><br><a href="https://github.com/jtriley/StarCluster/blob/develop/starcluster/balancers/sge/__init__.py#L59">https://github.com/jtriley/StarCluster/blob/develop/starcluster/balancers/sge/__init__.py#L59</a><br><br></div>I don't remember the exact reason for using that instead of the same logic as 'listclusters' above, but here's my guess a few years after the fact:<br></div>- Avoids another remote API call to AWS' tagging service to retrieve the tags for all instances within an account. This needs to be called every minute, so a speedy call to your cluster instead of to a remote API is beneficial<br></div>- qhost outputs the number of machines correctly configured and able to process work. If a machine shows up in 'listcluster' but not in 'qhost' it's likely not usable to process jobs, and would probably need manual cleanup.<br><br></div>HTH<br></div>Raj<br></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Mar 10, 2015 at 4:04 PM, Steve Darnell <span dir="ltr"><<a href="mailto:darnells@dnastar.com" target="_blank">darnells@dnastar.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">On a related topic, does anyone know how the load balancing feature tracks the cluster and its compute nodes? I have gotten into situations where listclusters
correctly reports that a cluster and its nodes are running (I can ssh into master and the nodes, etc.); however, loadbalance reports that the cluster is not running and refuses to balance the cluster.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Best regards,<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Steve<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <a href="mailto:starcluster-bounces@mit.edu" target="_blank">starcluster-bounces@mit.edu</a> [mailto:<a href="mailto:starcluster-bounces@mit.edu" target="_blank">starcluster-bounces@mit.edu</a>]
<b>On Behalf Of </b>Eduardo Gurgel Valente<br>
<b>Sent:</b> Tuesday, March 10, 2015 2:08 PM<br>
<b>To:</b> Nicholas Chammas<br>
<b>Cc:</b> <a href="mailto:starcluster@mit.edu" target="_blank">starcluster@mit.edu</a><br>
<b>Subject:</b> Re: [StarCluster] How does StarCluster track the clusters it's managing?<u></u><u></u></span></p><div><div class="h5">
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<p class="MsoNormal">Hi Nick,<u></u><u></u></p>
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<p class="MsoNormal"> Look at the security group it creates. It follows a naming convention. In addition there are tags with encrypted information at play.<u></u><u></u></p>
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<p class="MsoNormal">Eduardo<u></u><u></u></p>
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<p class="MsoNormal">On Mon, Mar 9, 2015 at 11:16 PM, Nicholas Chammas <<a href="mailto:nicholas.chammas@gmail.com" target="_blank">nicholas.chammas@gmail.com</a>> wrote:<u></u><u></u></p>
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<p style="margin:0px!important">Howdy!<u></u><u></u></p>
<p style="margin:0px!important">At <a href="http://youtu.be/vC3lJcPq1FY?t=7m20s" target="_blank">
this point in the StarCluster demo video</a>, the presenter runs the following command to list all the clusters being managed by StarCluster:<u></u><u></u></p>
<pre style="margin-right:1.8pt;margin-bottom:0in;margin-left:1.8pt;margin-bottom:.0001pt;line-height:14.4pt"><code><span style="font-family:Consolas;color:#333333;border:solid #cccccc 1.0pt;padding:6.0pt;background:ghostwhite">starcluster listclusters<u></u><u></u></span></code></pre>
<p style="margin:0px!important">How does StarCluster track all the clusters it’s managing? Is it through the use of EC2 instance tags? A pointer to the relevant code would also be helpful.<u></u><u></u></p>
<p style="margin:0px!important">I’m looking to implement a feature similar to <code>
<span style="font-size:10.0pt;font-family:Consolas;border:solid #eaeaea 1.0pt;padding:0in;background:#f8f8f8">listclusters</span></code> but for
<a href="http://spark.apache.org/docs/1.2.1/ec2-scripts.html" target="_blank">spark-ec2</a>. Tagging seems like the way to go to do that, but
<a href="https://issues.apache.org/jira/browse/SPARK-3332" target="_blank">we had some issues with it</a> when we used it with spark-ec2.<u></u><u></u></p>
<p style="margin:0px!important">So I’m curious to know how StarCluster did things.<u></u><u></u></p>
<p style="margin:0px!important">Nick<u></u><u></u></p>
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