On 20 July 2016 at 17:52, Rod Taylor <rod.tay...@gmail.com> wrote:
> I think it's important for communication channels to be defined separately > from the subscriptions. > I agree and believe it will be that way. Craig is working on allowing Replication Slots to failover between nodes, to provide exactly that requested behaviour. > So, I'd rather have: > > CREATE CONNECTION machine1; > CREATE CONNECTION machine2; > I think those map to replication slots. (This discussion might get a bit confusing if we try to guess exactly what each others terms mean, so I'll go no further than "I think"). > CREATE SUBSCRIPTION TO PUBLICATION mypub; > Yep > I'm not certain the subscription needs to be named. IMO, a publication > should have the same properties on all nodes (so any node may become the > primary source). If a subscriber needs different behaviour for a > publication, it should be created as a different publication. > Understood, its mostly to allow it to be dropped or altered and monitored. It's kindof like an index, it needs a name, we just don't much care what it is. > Documenting that ThisPub is different from ThatPub is easier than > documenting that ThisPub on node 1/2/4 is different from ThisPub on node > 7/8, except Node 7 is temporarily on Node 4 too (database X instead of > database Y) due to that power problem. > Which is why pg_dump support is important to allow us to sync up the definitions. > Clearly this is advanced. An initial implementation may only allow mypub > from a single connection. > Good input and clearly explained, thanks. If any of the above changes, these requirements will remain noted. > I also suspect multiple publications will be normal even if only 2 nodes. > Old slow moving data almost always got different treatment than fast-moving > data; even if only defining which set needs to hit the other node first and > which set can trickle through later. > Agreed -- Simon Riggs http://www.2ndQuadrant.com/ <http://www.2ndquadrant.com/> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
