Greg Smith wrote: > Heikki Linnakangas wrote: > > One such landmine is that the keepalives need to flow from client to > > server while the WAL records are flowing from server to client. We'll > > have to crack that problem for synchronous replication too, but I think > > that alone is a big enough problem to make this 9.1 material. > > > > This seems to be the real sticking point then, given that the > xmin/PGPROC side on the master seems logically straightforward. For > some reason I thought the sync rep feature had the reverse message flow > already going, and that some other sort of limitation just made it > impractical to merge into the main codebase this early. My hope was > that just this particular part could get cherry-picked out of there, and > that it might even have been thought about already in that context given > the known HS keepalive "serious issue". If there was a solution or > partial solution in progress to that floating around, my thought was > that just piggybacking this extra xid info on top of it would be easy > enough. > > If there's not already a standby to primary communications backchannel > implementation available that can be harvested from that work, your > suggestion that this may not be feasible at all for 9.0 seems like a > more serious concern than I had thought it was going to be.
I suspect the master could connect to the slave to pull an xid. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com PG East: http://www.enterprisedb.com/community/nav-pg-east-2010.do + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
