On Tue, 17 Jan 2006, Jules Gosnell wrote:

> >I believe that if you put some spare capacity in your cluster you will get
> >good availability. For example, if your minimum R is 2 and the normal
> >operating value is 4, when a node fails you will not be frantically doing
> >state transfer.
> >
> >
> OK - so your system is a little more relaxed about the exact number of
> replicants. You specify upper and lower bounds rather  than an absolute
> number, then you move towards the upper bound when you have the capacity ?

That's the idea. It's a bit like having hot spares, but all nodes are
treated on the same footing.

> >I would also just send a redirect. I don't think it's worth relocating a
> >session.
> >
> If you can communicate the session's location to the load-balancer, then
> I agree, but some load-balancers are pretty dumb :-)

I see .. I was hoping somebody was not going to say that. Even so, it
depends on the latency of the request when it actually request. After all,
this only happens after a failure. But no matter, you can also move the
session over.

Guglielmo

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