Hello,

I need to understand how to make an ip failover system.

Since pacemaker and corosync didn't went well on my debian (stable or sid : bugged as hell), I wondered why I couldn't make a simple, light system.

Coding is not considered a problem here. My concern is not to recreate the wheel but to make this thing working pretty quickly.

Scenario :
1)Node1 : public ip 123.456.789
2)Node2 : public ip 213.546.879

I would like to tell node2 to takeover the node1 ip in case node 1 dies.

I thought of a nat system : not convenient since I still have to indicate a port.

I should be able to setup a system which tells node2 to simulate node1 ip. And there is the first step. I own my dns server but even a reacting script won't go against the isp's cache.

What is left ?

What about an ip dedicated to face the public (my dns would always send traffic toward it) but create an order of priorities so that node1 comes first, node2 second.., node n nth.

One more time, the already existing solution don't interest me here. To understand, I need to make a small tool myself.

Could you help by telling me how I could cheat with this 3rd ip and my nodes to watch it and react ?

Many thanks,

Larry

You can try ucarp. You can visit this link for setup on Debian

Exactly what I need.

So I should rent a third public ip (additional to one of my node, say, node1, with no machine behind it) to be the shared one, right ?

3rd public shared ip : 222.333.111

So I will put this ip in the configuration to be listen on ? Like that :

Right ?

Thanks,

Larry

Yes you are correct. You need 3rd IP. So that will float between the machines. So Traffic will destined to that IP. Whichever machine is up and running will carry that IP.