<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=utf-8">
<META NAME="Generator" CONTENT="MS Exchange Server version 5.5.2658.34">
<TITLE>RE: [Beowulf] Concurrently open sockets limit on Linux system</TITLE>
</HEAD>
<BODY>
<P><FONT SIZE=2>Joe - good ideas!</FONT>
</P>
<P><FONT SIZE=2>As a debugging step we even ran the LM daemon as root, ulimit -a reports a file limit of 65535...</FONT>
</P>
<P><FONT SIZE=2>It's a permanently running daemon, not going through xinetd and it, annoyingly, produces no logs or sends anything to syslog.</FONT></P>
<P><FONT SIZE=2>Thanks for your thoughts...</FONT>
<BR><FONT SIZE=2>Simon</FONT>
</P>
<BR>
<BR>
<P><FONT SIZE=2>-----Original Message-----</FONT>
<BR><FONT SIZE=2>From: Joe Landman [<A HREF="mailto:landman@scalableinformatics.com">mailto:landman@scalableinformatics.com</A>]</FONT>
<BR><FONT SIZE=2>Sent: 2007 Jun 17 2:52 PM</FONT>
<BR><FONT SIZE=2>To: Galton, Simon</FONT>
<BR><FONT SIZE=2>Cc: 'beowulf@beowulf.org'</FONT>
<BR><FONT SIZE=2>Subject: Re: [Beowulf] Concurrently open sockets limit on Linux system</FONT>
</P>
<BR>
<P><FONT SIZE=2>Hi Simon</FONT>
</P>
<P><FONT SIZE=2>Galton, Simon wrote:</FONT>
</P>
<P><FONT SIZE=2>> (according lsof on the system running the license manager) seems to hold </FONT>
<BR><FONT SIZE=2>> a socket open during the duration of the job.</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> We want to run a couple of hundred of these jobs on our cluster, but </FONT>
<BR><FONT SIZE=2>> after job 126 the client can no longer connect to the license manager. </FONT>
</P>
<P><FONT SIZE=2>This seems to suggest somewhere that there is a 128 socket limit on the </FONT>
<BR><FONT SIZE=2>service. How is the license manager run? What does</FONT>
</P>
<P> <FONT SIZE=2>limit</FONT>
</P>
<P><FONT SIZE=2>or</FONT>
</P>
<P> <FONT SIZE=2>ulimit -a</FONT>
</P>
<P><FONT SIZE=2>tell you for the user that the license manager runs as? Any notes in </FONT>
<BR><FONT SIZE=2>system logs?</FONT>
</P>
<P><FONT SIZE=2>> The server hosting the license manager is otherwise fine, and you can </FONT>
<BR><FONT SIZE=2>> continue to perform network-based operations on and against it...</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> The vendor feels that they have not coded a specific limit; I'm </FONT>
<BR><FONT SIZE=2>> wondering if it's file descriptors or somesuch. I raised the limit of </FONT>
<BR><FONT SIZE=2>> FDs on the system to 65000+ and verified that the change took effect; no </FONT>
<BR><FONT SIZE=2>> change to the applications behaviour. It's a c-based app, compiled with </FONT>
<BR><FONT SIZE=2>> gcc on a Fedora Core 6 system, I believe.</FONT>
</P>
<P><FONT SIZE=2>Doesn't sound like an FD limit, but as a socket limit. Older inetd's </FONT>
<BR><FONT SIZE=2>had something like 20-40 connections per process. If you are serving </FONT>
<BR><FONT SIZE=2>this through xinetd or similar, you might be able to raise these limits.</FONT>
</P>
<P><FONT SIZE=2>Joe</FONT>
</P>
<P><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> Any thoughts?</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> Simon</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> CONFIDENTIAL AND PRIVILEGED INFORMATION NOTICE</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> This e-mail, and any attachments, may contain information that</FONT>
<BR><FONT SIZE=2>> is confidential, subject to copyright, or exempt from disclosure.</FONT>
<BR><FONT SIZE=2>> Any unauthorized review, disclosure, retransmission, </FONT>
<BR><FONT SIZE=2>> dissemination or other use of or reliance on this information </FONT>
<BR><FONT SIZE=2>> may be unlawful and is strictly prohibited. </FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> AVIS D'INFORMATION CONFIDENTIELLE ET PRIVILÉGIÉE</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> Le présent courriel, et toute pièce jointe, peut contenir de </FONT>
<BR><FONT SIZE=2>> l'information qui est confidentielle, régie par les droits </FONT>
<BR><FONT SIZE=2>> d'auteur, ou interdite de divulgation. Tout examen, </FONT>
<BR><FONT SIZE=2>> divulgation, retransmission, diffusion ou autres utilisations </FONT>
<BR><FONT SIZE=2>> non autorisées de l'information ou dépendance non autorisée </FONT>
<BR><FONT SIZE=2>> envers celle-ci peut être illégale et est strictement interdite.</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> ------------------------------------------------------------------------</FONT>
<BR><FONT SIZE=2>> </FONT>
<BR><FONT SIZE=2>> _______________________________________________</FONT>
<BR><FONT SIZE=2>> Beowulf mailing list, Beowulf@beowulf.org</FONT>
<BR><FONT SIZE=2>> To change your subscription (digest mode or unsubscribe) visit <A HREF="http://www.beowulf.org/mailman/listinfo/beowulf" TARGET="_blank">http://www.beowulf.org/mailman/listinfo/beowulf</A></FONT>
</P>
<BR>
<P><FONT SIZE=2>-- </FONT>
</P>
<P><FONT SIZE=2>Joseph Landman, Ph.D</FONT>
<BR><FONT SIZE=2>Founder and CEO</FONT>
<BR><FONT SIZE=2>Scalable Informatics LLC,</FONT>
<BR><FONT SIZE=2>email: landman@scalableinformatics.com</FONT>
<BR><FONT SIZE=2>web : <A HREF="http://www.scalableinformatics.com" TARGET="_blank">http://www.scalableinformatics.com</A></FONT>
<BR><FONT SIZE=2> <A HREF="http://jackrabbit.scalableinformatics.com" TARGET="_blank">http://jackrabbit.scalableinformatics.com</A></FONT>
<BR><FONT SIZE=2>phone: +1 734 786 8423</FONT>
<BR><FONT SIZE=2>fax : +1 866 888 3112</FONT>
<BR><FONT SIZE=2>cell : +1 734 612 4615</FONT>
</P>
<br><br><table bgcolor=white style="color:black"><tr><td><br>CONFIDENTIAL AND PRIVILEGED INFORMATION NOTICE<br>
<br>
This e-mail, and any attachments, may contain information that<br>
is confidential, subject to copyright, or exempt from disclosure.<br>
Any unauthorized review, disclosure, retransmission, <br>
dissemination or other use of or reliance on this information <br>
may be unlawful and is strictly prohibited. <br>
<br>
AVIS D'INFORMATION CONFIDENTIELLE ET PRIVILÉGIÉE<br>
<br>
Le présent courriel, et toute pièce jointe, peut contenir de <br>
l'information qui est confidentielle, régie par les droits <br>
d'auteur, ou interdite de divulgation. Tout examen, <br>
divulgation, retransmission, diffusion ou autres utilisations <br>
non autorisées de l'information ou dépendance non autorisée <br>
envers celle-ci peut être illégale et est strictement interdite.</td></tr></table></BODY>
</HTML>