Hi Andrew, Thanks for confirming my suspicion. Sorry for the late reply, I was away from civilization for a while :)
Radu ----- Original Message ---- From: Andrew Beekhof <[EMAIL PROTECTED]> To: General Linux-HA mailing list <[email protected]> Sent: Sunday, September 30, 2007 11:38:15 AM Subject: Re: [Linux-HA] Process "resume" after failover On 9/29/07, Radu Handorean <[EMAIL PROTECTED]> wrote: > 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 heartbeat is service-agnostic which means we dont want/need to understand what it is we're managing so the only state that is transfered is state which you or your application has transfered itself to some extent we support the ability to migrate resources, but that only really makes sense when A is healthy... (its hard to migrate data from a dead machine) so for the scenario you mentioned below to work, your application would have had to have already replicated enough information before A crashed. but just to re-iterate, your application needs to be cluster-aware for this to work. > 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 > > > > > > ____________________________________________________________________________________ > Got a little couch potato? > Check out fun summer activities for kids. > http://search.yahoo.com/search?fr=oni_on_mail&p=summer+activities+for+kids&cs=bz > _______________________________________________ > Linux-HA mailing list > [email protected] > http://lists.linux-ha.org/mailman/listinfo/linux-ha > See also: http://linux-ha.org/ReportingProblems > _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems ____________________________________________________________________________________ Catch up on fall's hot new shows on Yahoo! TV. Watch previews, get listings, and more! http://tv.yahoo.com/collections/3658 _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
