Re: Synchronous Standalone Master Redoux

> Please, stop arguing on all of this: I don't think that adding an
> option will hurt anybody (specially because the work was already done
> by someone), we are not asking to change how the things work, we just
> want an option to decided whether we want it to freeze on standby
> disconnection, or if we want it to continue automatically... is that
> asking so much?

The objection is that, *given the way synchronous replication currently
works*, having that kind of an option would make the "synchronous"
setting fairly meaningless. The only benefit that synchronous
replication gives you is the guarantee that a write on the master is
also on the standby. If you remove that guarantee, you are using
asynchronous replication, even if the setting says synchronous.

I think what you really want is a separate "auto-degrade" setting. That
is, a setting which says "if no synchronous standby is present,
auto-degrade to async/standalone, and start writing a bunch of warning
messages to the logs and whenever anyone runs a synchronous
transaction". That's an approach which makes some sense, but AFAICT
somewhat different from the proposed patch.

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com