Re: [cobalt-users] redundant system

[Kris Dahl <kris@xxxxxxxxxxxxx>]

on 1/26/00 8:25 AM, Nathan Martinez at nathanm@xxxxxxxxxx wrote:

> We are wanting to get into the web hosting business.  We have purchased a
> couple of Raq2 units.  We are really impressed by the ease of administration
> that they offer.  We were wanting to actually store all of our data on an
> external RAID system.  We also wanted to setup a cluster type of system in
> order to help balance out the load.  This will also help us if one of the
> machines decides to not work one day -- the rest of the cluster would just
> take over (another reason for having a central storage location).  Has
> anyone done something similar with the Raq2 units?  What kind of solutions
> are out there?  We are just getting started and want to make sure that we
> are making the right hardware decision.  Thanks for any input that you can
> offer.

You're probably going to want to use some software for the RedHat folks
called Piranha.  I could only locate an RPM--no sources on the RedHat site.

For an overview and a howto check out
http://www.redhat.com/support/docs/howto/piranha

It would be interesting to see a cluster of Raqs with load balancing.

However, you are going to need to have 1 or more Linux machines (probably a
standard RedHat box running i386 would be best) to act as your load
balancer.  Then it just evenly distributes the bandwidth from one Raq2 to
the next.  One issue would be how you are planning to distribute and mirror
your machines.  You'd have to make one of the machines a 'master'.

This also won't really work for more than one 'site' at a time.  Meaning
that even if you have a 'master' raq2, you're going to have a replication
process that won't be in real time.  So users won't be able to upload their
page to the 'master' and expect it to be online right then on all of the
machines.  Actually, if you were going over NFS or something, I guess you
could, but you would definitely lose all advantages of having the 'ease of
management'.  I suppose you COULD keep the interface, and write some scripts
to automatically replicate things over all your Raqs, but you are opening a
whole can of worms that SOUND like it might exceed your entry requirements.

The Raq2 doesn't really qualify as 'heavy iron' as far as I am concerned,
and am thinking that if you are looking to get into really serious web
hosting and looking at going with a RAID type solution, I'd suggest getting
more, bigger, faster standard Linux machines.  A good one to go with may be
HP's LPr with a NetRaid 3si RAID Controller.  Or perhaps a LC3 with NetRaid
3si & hotswap, or a LH4/LH4r with built-in RAID controller and massive
internal hot-swap drive storage.  The LH4 is quite a machine--and can be
rack mounted (at like 10U or so), multi-processor capable, can have (i
think) 4 gigs of memory.  Its a little beefy for a web server.

I think the killer combo right now would be a pair of LPr's with NetRaid
3si's--one as a dedicated DB server behind the other as a dedicated web/php
server.  And it is like 2U in a rack.

HP is also coming out with a new rack-mounted 2U that should be way
kickass--not sure of the specifics.

-k