Have you read the 8.2 documentation about this: http://www.postgresql.org/docs/8.2/static/high-availability.html --------------------------------------------------------------------------- Ben wrote: > Hi guys. I've inherited a system that I'm looking to add replication to. > It already has some custom replication code, but it's being nice to say > that code less than good. I'm hoping there's an existing project out there > that will work much better. Unfortunately, I'm not seeing anything that > obviously fits my needs, so maybe somebody here can suggest something. > > I've got a single cluster in the datacenter and dozens of remote sites. > Many of these sites are on unreliable connections to the internet, and > while they're online more often then not, when their network will go down > isn't known, and even when it's up, the network isn't that fast. > > A vast majority of activity occurs at these remote sites, with very little > at the datacenter cluster. That said, the datacenter cluster needs to keep > pretty good copies of most (but not all) of the data at each site. > Obviously the network unrealiability puts a limit on how up to date the > datacenter can be, but loosing data is considered Bad. So, for instance, > restoring the daily backup of each site at the datacenter is too > infrequent. > > Each site will replicate to its own schema in the datacenter cluster, so I > don't *think* I need a multi-master solution.... but at the same time, > because data will be coming from multiple sites, simply replaying WAL > files at the datacenter won't work. > > In addition, there will be some data changes made at the datacenter that > will need to replicate to all of the remote sites as soon as they're > online. It's ok if data being replicated from the datacenter ends up in a > different schema at the remote sites than the schema which holds the data > that will be replicated back to the datacenter. > > My current best guess of what to do is create a global schema at every > database, a local schema at each site, and a schema for each site at the > datacenter. Then I can use Slony to replicate the global schema from the > datacenter to each site, and again use Slony to replicate the local schema > from each site to that site's schema in the datacenter. But I'm not too > familiar with Slony, and from what I understand, using Slony with bad > networks leads to bad problems. I'm also not sure that Slony supports > replicating from multiple sources to the same postgres install, even if > each replication process is writing to a different schema. > > Are there any better options? Or is my Slony idea not so bad? > > ---------------------------(end of broadcast)--------------------------- > TIP 6: explain analyze is your friend -- Bruce Momjian bruce@xxxxxxxxxx EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. +
