SV: [SPAM] Re: multiple thin client servers

[Gavin McCullagh]

Hi,

On Thu, 23 Nov 2006, Mattias Hemmingsson wrote:

> We are now testing out skolelinux with new edu 6.10 to get them to work
> together.

I can see why some people want to do this, but I really want to keep things
simple, so it's not of much interest to me.

> But skolelinux don't have any solution to cluster edu servers.
> And ltsp-mosix is too old to use.
> To cluster server I'm looking at LVS to load balance the servers.
> And then Webmin to cluster the server so package and shell scripts are the
> same on all servers.

I must admit, my way of load balancing would just be to attempt to randomly
distribute the user logins across the servers.  Several DNS entries would
be enough for that I think.  I guess it depends on what you need but I
don't think that should be too bad and it keeps things nice and simple. 

After that, I'm really just looking for resiliency.  It seems to me that
the best criticism of thin client systems is that they create a single
point of failure.  At all costs, I'd rather not see that exposed.  I think
redundant dns and dhcp should be fairly straightforward.  I know you can do
something similar with both LDAP and NIS.  It makes no sense to use NIS if
Edubuntu is implementing LDAP but there's no support as yet for LDAP user
management -- unless we start testing the tool Oliver is looking at.

It would be really excellent to have a simple, standardised way to achieve
a master/slave config this in edubuntu.  I guess that should come down the
line after the move to LDAP.  For now, I can use an nfs mount and some
nasty kludge like a shell script monitoring datestamps and rsyncing
/etc/{passwd,shadow,group,gshadow,...}.

The big difficulty always seems to be a redundant file store.  I guess it
should be good enough to rsync a copy nightly and be ready to switch the
nfs mounts to it in the event of disaster.  We don't have the budget for a
proper NAS, but that's okay.

Thanks for the suggestions.

Gavin