[Linux-HA] Process "resume" after failover

[Radu Handorean]

Hello,

So we have NodeA (active) and NodeB (standby). When NodeA fails (say one of the monitored processes dies and the others are killed and the node rebooted) will the processes on NodeB start from scratch? I wonder about the transfer of state information from A to B which I don't believe is possible and thus processes on NodeB would look like newly started processes. If one has a webserver that starts on NodeB it may not be such a big deal to start it fresh, but I am thinking about the following scenario: NodeA plays back some mp3 file and about 50% into the song the process crashes and NodeB would have to continue playing from that point forward. In this case the "resume" or "continue" behavior is clearly preferred (required :) ). However, it seems unlikely that this will happen without the application being aware of such scenarios (e.g. use checkpoints). The entire HA mechanism is definitely oblivious of what happens "above", at the app level. 

Can anybody comment on this? Maybe pointers to literature I missed?

Thanks!!
Radu




       
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