> -----Original Message----- > From: pgsql-general-owner@xxxxxxxxxxxxxx > [mailto:pgsql-general-owner@xxxxxxxxxxxxxx] On Behalf Of > Arnaud Lesauvage > Sent: 31 May 2006 10:39 > To: Magnus Hagander > Cc: pgsql-general@xxxxxxxxxxxxxx > Subject: Re: [GENERAL] Best high availability solution ? > > Otherwise, is the clustering service really necessary ? > Aren't there simple "virtual IP addresses" solutions available ? > I could have a single virtual IP for the 2 servers, and having an > automatic failover if the master server is down ? The slave would > never be accessed by clients directly (only after a failover) but > would by synchronized with the master (slony-I). > > Does this kind of software exist in the windows world ? Slony-I only exists for Windows in a not-even-beta state at the moment, so even if you get things up and running using a virtual IP solution you will be hand-holding Slony until it gets properly released. The 'virtual IP' solution you are looking for is called Network Load Balancing btw, and is on standard edition. I really don't see how you would make it work safely though - it's designed more for load distribution, and though you can weight rules towards one server, there's no guarantee that it won't send a connection to the backup server. You would also need some way of automatically handling the Slony failover which is definitely not recommended. If I'm honest, I think your boss is going to be disappointed. You would add a *lot* of complexity to the system to make it handle failures with zero intervention, and that extra complexity is probably more likely to go wrong than a single server. I'd spend your time and money on making sure your raid & ups are good, that you are running on server grade hardware with ECC RAM, and that you have good out of band management facilities so even if you are away from the office you can connect via VPN/modem or whatever and fix things. Regards, Dave.
