Re: Configuring synchronous replication

On Thu, 2010-09-23 at 11:43 -0400, Tom Lane wrote:
> > What other problems are there that mean we *must* have a file?
>
> Well, for one thing, how do you add a new slave? If its configuration
> comes from a system catalog, it seems that it has to already be
> replicating before it knows what its configuration is.

Or the slave gets a connection string to the master, and reads the
configuration from there - it has to connect there anyway...

The ideal bootstrap for a slave creation would be: get the params to
connect to the master + the replica ID, and the rest should be done by
connecting to the master and getting all the needed thing from there,
including configuration.

Maybe you see some merit for this idea: it wouldn't hurt to get the
interfaces done so that the master could be impersonated by some WAL
repository serving a PITR snapshot, and that the same WAL repository
could connect as a slave to the master and instead of recovering the WAL
stream, archive it. Such a WAL repository would possibly connect to
multiple masters and could also get regularly snapshots too. This would
provide a nice complement to WAL replication as PITR solution using the
same protocols as the WAL standby. I have no idea if this would be easy
to implement or useful for anybody.

Cheers,
Csaba.