haproxy listening to all interface is safe for a heartbeat cluster? (was: High Availability question)

Hi all,

having read the previous tread, what I understood was that for a heartbeat cluster with haproxy it is a safe configuration to have haproxy just listen to all interfaces and it will automatically pick up the newly assigned address once a fail-over happens?

Can I be sure haproxy recognises the new IP address after a fail-over without it being restarted (or may be this is nothing haproxy has to worry about, because it's a kernel thing)?

How about may be Apache?

Until now I always created orders and colocations to start and stop haproxy/apache when a fail-over takes place - just to be correct.

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kind regards
Dirk Taggesell