Re: Configuring synchronous replication

On Thu, Sep 23, 2010 at 1:03 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> On Thu, Sep 23, 2010 at 12:52 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>> Um ... so how does this standby know what master to connect to, what
>>> password to offer, etc?  I don't think that "pass down parameters after
>>> connecting" is likely to cover anything but a small subset of the
>>> configuration problem.
>
>> Huh?  We have that stuff already.
>
> Oh, I thought part of the objective here was to try to centralize that
> stuff.  If we're assuming that slaves will still have local replication
> configuration files, then I think we should just add any necessary info
> to those files and drop this entire conversation.  We're expending a
> tremendous amount of energy on something that won't make any real
> difference to the overall complexity of configuring a replication setup.
> AFAICS the only way you make a significant advance in usability is if
> you can centralize all the configuration information in some fashion.

Well, it's quite fanciful to suppose that the slaves aren't going to
need to have local configuration for how to connect to the master.
The configuration settings we're talking about here are the things
that affect either the behavior of the master-slave system as a unit
(like what kind of ACK the master needs to get from the slave before
ACKing the commit back to the user) or the master alone (like tracking
how much WAL needs to be retained for a particular disconnected slave,
rather than as presently always retaining a fixed amount).

--
Robert Haas
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