Linux HA / cluster: what are the differences between Pacemaker, Heartbeat, Corosync, wackamole?

Question

Can you help me understand Linux HA?

• Pacemaker, Heartbeat, Corosync seem to be part of a whole HA stack, but how do they fit together?
• How does wackamole differ from Pacemaker/Heartbeat/Corosync? I've seen opinions that wackamole is better than Heartbeat because it's peer-based. Is that valid?
• The last release of wackamole was 2.5 years ago. Is it still being maintained or active?
• What would you recommend for HA setup for web/application/database servers?

Answer 1

Depends what kind of app is using the HA setup, MySQL? A cluster filesystem?

I'd recommend whichever HA setup redhat use in their cluster tools. They tend to know which package is best for the general case. Accord into this is heartbeat, however Planet HA has interesting articles depending on what kind of stack you are configuring.