Hi Ewan,
So at Glasgow, we just have the one squid (Frontier + cvmfs). There's
no official failover, and, indeed, we think that one of the causes of
our issue with cvmfs was the one squid not having something to fall
back to.
I think that we'd be happy with 2 squids in a load-balanced
configuration here, not least because the network distance for CVMFS
-> another squid is going to be about the same as that to RAL... that
said, there's something to be said for multiple levels of resiliency.
Sam
On 18 August 2011 15:25, Ewan MacMahon <[log in to unmask]> wrote:
> Hi all,
>
> I've just had an interesting lesson in what happens to cvmfs
> when its one and only squid server dies underneath it, and
> now I'm thinking about getting some redundancy into the
> system.
>
> cvmfs itself supports multiple squidd, so it's just a matter
> of having multiple squid servers available. The Tier 1 has
> a couple, but for everyone else I was wondering whether it
> would make sense to handle this in a similar manner to how
> we deal with the Frontier squids and have cross-site failover?
>
> As far as I can see we could:
> - use the same basic idea,
> - use the exact same relationships, so everyone fails over
> their cvmfs squid to the same place they fail over their
> Frontier squid (which makes sense because in a lot of
> cases they're the same squid),
> - have everyone fail over to the Tier 1,
> - something else,
> - nothing at all, and just leave it to each site to run
> a pair of squids.
>
> I think I'd favour either the second or third options, but
> I'd be interested to know what everyone thinks, and indeed
> how everyone else with deployed cvmfs is handling this now.
>
> Ewan
>
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