On Fri, Sep 17, 2004 at 06:04:52PM -0700, Mitch (WebCob) wrote: > [ Will Yardley wrote ]
> > Is there any mechanism to have Courier (IMAP / POP3) check more than > > one MySQL server (so that if one fails, Courier can still > > authenticate users)? I know that Postfix allows this if you're using > > MySQL for virtual maps / aliases. > This doesn't have to be courier's problem... It doesn't have to be, but that's by far the easiest way to deal with the situation. > I can see this would make it easier, but there are other ways to skin > the cat. You cluster the database, and use ip failover scripts to move > the live IP to the backup server in case of failure... Yes... we already have some of the backend setup to do this (for other stuff) - but it probably wouldn't be worth the effort in the event of a short term failure.... I'm not concerned so much about a complete failure (in that case, we could quickly recreate the db and switch the virtual IP to a different machine), but rather short term failures, or times when the max connections configured in the database server is getting exceeded. I'd also be concerned that any simplistic mechanism which would automatically switch the live IP between machines might result in a "flip-flop" type situation if the problem was general overloading (one db goes down, the other comes back). (also, I believe it would be necessary for the host taking over the IP to send an ARP request etc., unless you want to use LVS or something) Obviously we're already talking about doing replication on the DB servers here (either way), but I'd definitely be a lot happier if it were possible to have the option to specify multiple MySQL servers in the config file. This would also makes it somewhat easier to effect primitive load balancing across a cluster of machines. ------------------------------------------------------- This SF.Net email is sponsored by: YOU BE THE JUDGE. Be one of 170 Project Admins to receive an Apple iPod Mini FREE for your judgement on who ports your project to Linux PPC the best. Sponsored by IBM. Deadline: Sept. 24. Go here: http://sf.net/ppc_contest.php _______________________________________________ courier-users mailing list [EMAIL PROTECTED] Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users
