[ILUG] distributed lock management...

[John P . Looney]

On Wed, Feb 21, 2001 at 03:11:26PM -0000, Wynne, Conor mentioned:
> Anyone tried lifekeeper for linux? It's basically MSCS (which I don't like
> for obvious reasons and others) but with support up to 16 nodes rather than
> a measely two. 

 I didn't. What I've running at the moment is ipvs & mon & heartbeat
setup to do clustering for mysql, http, postfix and courier imap. Works
well - but there is a ~2 second gap between mon noticing that a service is
down, and changing the routing tables for it. It nats everything out of
the cluster, so it looks like it's all one big machine.

 Heartbeat's just used for a fail over router. Problem there being that
you lose the nat tables - so if your router dies, all your connections
drop, and it's a second or two before you can reconnect to anything. Not
brillant.

 Maybe worthy of an ILUG talk sometime soon :)

> You need fibre channel for the 16 nodes - mucho deneros, else you can use
> shared scsi and only two nodes. But you can cluster applications, we setup
> MySql and Apache, and brutally shut off machines for the laugh, and it was
> almost seamless as far as the clients were concerned - 20 seconds as far as
> I can remember - but this is adjustable - and better than MSCS can do. 

 How does it all work ? What does it use for shared storage (which is my
big problem at the moment. NetApp clusters are expensive, as are dual
attach SCSI enclosures.

 Though if someone had an old one that they'd sell me, I'd be well
interested.

Kate

-- 
 When I say 'free', I mean 'free': free from bond, of chain or command: 
to go where you will, even to Mordor, Saruman, if you desire. " 
    -- Gandalf, paraphrasing the choice between Free and Non-free software