On Tue, Oct 19, 2010 at 13:14, Stefan Kaltenbrunner <ste...@kaltenbrunner.cc> wrote: > Josh Berkus wrote: >> >> Hackers, >> >> What purpose is served, exactly, by max_wal_senders? >> >> In order for a standby to connect, it must have a superuser login, and >> replication connections must be enabled in pg_hba.conf. How is having one >> more setting in one more file you have to enable on the master benefitting >> anyone? >> >> Under what bizarre set of circumstances would anyone have runaway >> connections from replicas to the master? >> >> Proposed that we simply remove this setting in 9.1. The real maximum wal >> senders should be whatever max_connections is. > > I disagree - limiting the maximum number of replication connections is > important for my usecases. > Replication connections are significantly more heavilyweight than a normal > connection and right now I for example simply use this setting to prevent > stupid mistakes (especially in virtualized^cloudstyle environments). > > What we really should look into is using a less privileged role - or > dedicated replication role - and use the existing per role connection limit > feature. That feature is unlimited by default, people can change it like > for every role and we can git rid of that guc.
+1 for being able to control it that wya - that should keep it simple for the newbie usecase, while retaining the ability for fine-grained control for those who need it. I think it's already on the TODO for 9.1 to use a separate role for it... If we want something fixed *now*, should we perhaps just bump the *default* value for max_wal_senders to 5 or something? -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
