Failover to closest host

[rantav]

When failing over the the next host, if there's a long list of available hosts, any host may be chosen by the client as a failed over host. This could mean that the host is in a different datacenter.
An improvement this this is to choose the host based in shortest IP distance, e.g. prefer host in the same subnet.
Even better is a pluggable EndPointSnitch

[zznate]

Being as configuration happy as I am, I would like to have some mechanism of defining failover groups as hosts are requested/added to the pool. Not sure how that would work, but I think being declarative would be nice, as I know where all my iron is.

A default similar to cassandra's EndPointSnitch xor'ing IP addresses would be good though.

[cheetah100]

It would be good to have some intelligence in selecting hosts. Keeping track of response times for example. A Pluggable approach to host selection strategies would be good.

[rantav]

@cheetah100 I think we're on the same page, it's just that this subject was never brought up in the priority high enough.
Now, however, I think Nate will have a chance to spend some time rethinking of this and coming up with a better implementation (I only wish I had the time for that...)

[zznate]

LoadBalancingPolicy is now available as an extension point.

[patricioe]

And the Phi accrual policy is available as well.

Closing the ticket.