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[bmartin@penguincomputing.com: Re: [Linux-ha-dev] Re: [riel@conectiva.com.br: [ANNOUNCE] linux-cluster list]]

Hi everybody,

I just posted this to linux-ha-dev and Alan Robertson reminded
me that I probably should have posted it here too :)



On Thu, Mar 01, 2001 at 02:20:20AM +0200, Pekka Savola wrote:
> On Wed, 28 Feb 2001, Chris Wright wrote:
> 
> > this may be interesting.
> > -chris
> 
> I believe this is about Clustering in supercomputing sense (mosix,
> beowulf, etc.) and has very little to do with High Availability.
> 
> People should be really careful when they talk about clustering..
> 
Yes, they should.

Very careful.

To me people who think heartbeat is just about high availabity and
failover seem to be missing the point.  

Yea, so mosix clusters typically don't use heartbeat.  And beowulf 
clusters don't either.  For that matter most people don't use heartbeat
right now.  

Except for the high availability failover case, one that many people
don't even think fits the definition of a cluster.  

But that is thinking in the present, the world of what's available now
for production.  

Currently the state of clustering under linux is quite varied and 
fragmented, with a myriad of approaches to a myriad of projects.  

What Rik is trying to do is to unify those efforts, specifically as they
relate to the linux kernel.

What Alan is trying to do is unify those same efforts in userspace.  This
means that he won't be producing any kind of distributed shared memory
or process migration, but that is ok as most problems are split somewhere
between userspace and kernel space.

So I think that this is all very relevant and that it would be best if
we all could share as much of a common base as possible.    

It is this very attitude that 'oh what they are doing is different.  It 
doesn't apply here' that fragments the different clustering efforts now
underway.

I agree that many of us have different agendas and are doing vastly 
different things.  

But that doesn't mean that we all don't need many of the very same
components.  

For example, the basics services (interfaces?) that heartbeat provides
could very well be useful in a mosix context.  

Suppose you have your mosix cluster all running off GFS, and one of
your machines stops responding?  What do you do to make sure it's not 
just experiencing some _really_ bad scheduling problems?  

STONITH!

So anyways, I sent Rik some email outlining the basics of what heartbeat
does and is intended to do, just to make sure he knows of the project.

Regards,

Brian

> >
> > ----- Forwarded message from Rik van Riel <riel@conectiva.com.br> -----
> >
> > Date:	Wed, 28 Feb 2001 12:40:44 -0300 (BRST)
> > From: Rik van Riel <riel@conectiva.com.br>
> > To: <linux-cluster@nl.linux.org>
> > Cc: <linux-kernel@vger.kernel.org>, <lwn@lwn.net>
> > Subject: [ANNOUNCE] linux-cluster list
> >
> > On special request, this message is re-sent with [ANNOUNCE] in
> > the subject and the non-announce parts removed.  ;)
> >
> > Feel free to pass this on to whomever you think might be interested.
> > ----
> > 	[on general clustering stuff]
> > On Tue, 27 Feb 2001, David L. Nicol wrote:
> > > Is there a good list to discuss this on?  Is this the list?
> > > Which pieces of clustering-scheme patches would be good to have?
> >
> > I know each of the cluster projects have mailing lists, but
> > I've never heard of a list where the different projects come
> > together to eg. find out which parts of the infrastructure
> > they could share, or ...
> >
> > Since I agree with you that we need such a place, I've just
> > created a mailing list:
> >
> > 	linux-cluster@nl.linux.org
> >
> > To subscribe to the list, send an email with the text
> > "subscribe linux-cluster" to:
> >
> > 	majordomo@nl.linux.org
> >
> >
> > I hope that we'll be able to split out some infrastructure
> > stuff from the different cluster projects and we'll be able
> > to put cluster support into the kernel in such a way that
> > we won't have to make the choice which of the N+1 cluster
> > projects should make it into the kernel...
> >
> > regards,
> >
> > Rik
> > --
> > Linux MM bugzilla: http://linux-mm.org/bugzilla.shtml
> >
> > Virtual memory is like a game you can't win;
> > However, without VM there's truly nothing to lose...
> >
> > 		http://www.surriel.com/
> > http://www.conectiva.com/	http://distro.conectiva.com/
> >
> >
> > -
> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at  http://www.tux.org/lkml/
> >
> > ----- End forwarded message -----
> >
> > ------------------------------------------------------------------------------
> > Linux HA Web Site:
> >   http://linux-ha.org/
> > Linux HA HOWTO:
> >   http://metalab.unc.edu/pub/Linux/ALPHA/linux-ha/High-Availability-HOWTO.html
> > ------------------------------------------------------------------------------
> >
> 
> -- 
> Pekka Savola                  "Tell me of difficulties surmounted,
> Netcore Oy                    not those you stumble over and fall"
> Systems. Networks. Security.   -- Robert Jordan: A Crown of Swords
> 
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