From siegert@sfu.ca Fri Nov 24 13:56:48 2000
Date: Wed, 22 Nov 2000 19:25:47 -0800 (PST)
From: Martin Siegert <siegert@sfu.ca>
To: Joey Raheb <jraheb@julian.uwo.ca>
Cc: beowulf@beowulf.org
Subject: Re: NIS?

> I am in the process of building up a small test cluster,  I was wondering is
> NIS needed and why/why not?  I have NIS setup on the small three node
> cluster, but telnet stopped working?  WHY? When I try to run the
> telnetdaemon it tells me bind: Permission denied.  Someone please help, I'm
> pulling my hair out!

I can't answer your last question, but I can answer your first:
No you don't need NIS.

Since this question comes up once in a while, I've set up a web page that
describes the fairly simple setup that we are using:

http://www.sfu.ca/~siegert/beowulf_setup.html

I hope this helps or at least gets you going. YMMV.
Comments are welcome.

Cheers,
Martin

========================================================================
Martin Siegert
Academic Computing Services                        phone: (604) 291-4691
Simon Fraser University                            fax:   (604) 291-4242
Burnaby, British Columbia                          email: siegert@sfu.ca
Canada  V5A 1S6
========================================================================

_______________________________________________
Beowulf mailing list
Beowulf@beowulf.org
http://www.beowulf.org/mailman/listinfo/beowulf

From becker@scyld.com Fri Oct  5 11:59:40 2001
Date: Fri, 5 Oct 2001 11:25:09 -0400 (EDT)
From: Donald Becker <becker@scyld.com>
To: Steven Timm <timm@fnal.gov>
Cc: beowulf@beowulf.org
Subject: Re: NIS?

On Fri, 5 Oct 2001, Steven Timm wrote:

> The issue is not only the cpu load on the server, if I understand
> it correctly, but also the network load.  150 nodes doing
> a simultaneous yp lookup is enough to make timeouts.
> 
> >From what I have seen (running 2.2.x kernels and ypbind-1.7-8)
> there is also a yp lookup that happens as long as you have
> files and nis in nsswitch.conf, even if the user is root and
> happens to be found in files.  Has anyone else seen this?

Yes.  Use 'strace' to watch it happen.
The always-on NIS code is built into glibc, not ypbind.  The glibc code
will attempt to communicate with NIS during library initialization, well
before it knows if there are any queries to be made.  It's just part of
the glibc bloat.

[[ What was RGB implying when claiming that that NIS "wasn't dark evil"
and then immediately mentioning vampire taps? ]]

It's instructive to study the output of 'strace' during the start-up of
a trivial program.  Every I/O attempt has the potential to be a
synchronization bottleneck if the cluster isn't designed carefully.
Those details are important to cluster scalability, which is a separate
issue from application/algorithm scalability.

Donald Becker				becker@scyld.com
Scyld Computing Corporation		http://www.scyld.com
410 Severn Ave. Suite 210		Second Generation Beowulf Clusters
Annapolis MD 21403			410-990-9993


_______________________________________________
Beowulf mailing list, Beowulf@beowulf.org
To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
