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I'm wondering if anyone can give some clustering recommendations to me. I'm currently on Linode, which I'm impressed and happy with, but they (along with just about every other VPS provider I know of) don't allow broadcast/multicast addressing, only unicast.

The tools I've been trying to set up for failover (keepalived / wackamole+spread) only work over multicast, as far as I know. If I'm wrong, please let me know and point me to an example configuration.

I've now read that Heartbeat can use unicast, but that it does it over multicast protocol. Not sure if this will work or not, and I'd like opinions before I try to spend more time installing it.

My ultimate goal is to have N servers share N ip addresses, and if one server goes down, server A takes its IP, if another server goes down, server B takes its IP, etc. From what I've read wackamole is the best option for this, but I just can't get spread to work on Linode.

Has anyone successfully set up clustering/failover on a VPS/cloud provider (without multicast)? I'd really appreciate some pointers and advice.

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Can you comment on the general use case here? I'm just wondering what it is that you're trying to achieve. – Till Jun 30 '10 at 18:18
Just to add to my question - the way I see it, I'd rather do something like loadbalancing. E.g. in the front of two loadbalancers that proxy to the rest of the servers. No need to setup heartbeat and the like. But I'm not sure what the application is. – Till Jun 30 '10 at 18:40

I think you don't necessarily need multicast, but you definitely need "floating" IP addresses which can jump from one server to the next. And you need a provider that gives you the ability to have IP addresses not bound to a particular server.

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Thanks for the response. I have floating IPs I can use (unlimited), so that's not my problem. Any idea on how to use HA tools (keepalived, wackamole, heartbeat, etc) without multicasting? – andrew Jun 24 '10 at 17:43

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