[Linux-HA] Heartbeat failover condition

[Eric Zhang]

Hi, linux-ha:

    I am a newbie of Heartbeat. I have a question now: Will the
heartbeat failover from primary server to backup server when the
resource is unavailable? I mean, suppose such a situation: I run Apache
as my web server and it is the resource that hearbeat will monitor, when
the primary server was down, the backup server will not hear the
heartbeat so the failover begins. But if the heartbeat daemon of primary
server works right but my Apache doesn't work, what will happen? Will
this trigger a failover event?

    Actually, I don't know the details of heartbeat's resource manager.
Heartbeat's resource manager needs the resource scripts implement
"status, start, stop" commands, that means I can do a lot of jobs in
these three commands, I can do a lot of checking works in "status"
command, if my resource works abnormally, the resource script will
return words "bad" or some other things, whatever, just no "ok". If so,
will heartbeat begin failover when my resource script doesn't return
"ok" or, heartbeat only begin failover when the primary server doesn't
send heartbeat packages?

    I wish everyone can understand me. Thanks for any suggestions.

Eric Zhang
2006-11-02