On Mon, Oct 14, 2013 at 10:56 PM, Josh Berkus <j...@agliodbs.com> wrote: > On 10/13/2013 01:38 AM, Gibheer wrote: >> So it will ensure that max_wal_senders is used for reserving >>> connection slots from being used by non-super user connections. I find >>> new usage of max_wal_senders acceptable, if anyone else thinks >>> otherwise, please let us know. > > I think otherwise. > > Changing max_wal_senders requires a restart. As such, we currently > advise users to set the setting generously: "as many replication > connections as you think you'll ever need, plus two". If > max_wal_senders is a reservation which could cause the user to run out > of other connections sooner than expected, then the user is faced with a > new "hard to set" parameter: they don't want to set it too high *or* too > low.
It is documented in the patch that configuration max_wal_senders is reserved from max_connections. So it will not cause the user to run out of other connections sooner than expected, if both the variables are configured properly. > This would result in a lot of user frustration as they try to get thier > connection configuration right and have to restart the server multiple > times. I find few new features worth making it *harder* to configure > PostgreSQL, and reserved replication connections certainly don't qualify. > > If it's worth having reserved replication connections (and I can see > some reasons to want it), then we need a new GUC for this: > "reserved_walsender_connections" Having new variable also might make users life difficult, as with new variable he needs to take care of setting 3 parameters (max_wal_senders, reserved_walsender_connections, max_connections) appropriately for this purpose and then choosing value for reserved_walsender_connections will be another thing for which he has to consult. With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
