On Wed, Mar 14, 2012 at 8:53 AM, Josh Berkus <j...@agliodbs.com> wrote: > All, > > I've discovered a built-in performance issue with replication failover > at one site, which I couldn't find searching the archives. I don't > really see what we can do to fix it, so I'm posting it here in case > others might have clever ideas. > > 1. The Free Space Map is not replicated between servers. > > 2. Thus, when we fail over to a replica, it starts with a blank FSM. > > 3. I believe replica also starts with zero counters for autovacuum. > > 4. On a high-UPDATE workload, this means that the replica assumes tables > have no free space until it starts to build a new FSM or autovacuum > kicks in on some of the tables, much later on.
If it's really a high-UPDATE workload, wouldn't autovacuum start soon? Regards, -- Fujii Masao NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
