Re: Backup history file should be replicated in Streaming Replication?

On Tue, 2009-12-22 at 14:02 -0500, Tom Lane wrote:
> Simon Riggs <simon@2ndQuadrant.com> writes:
> > The backup history file is a slightly bit quirky way of doing things and
> > was designed when the transfer mechanism was file-based.
> 
> > Why don't we just write a new xlog record that contains the information
> > we need?
> 
> Certainly not.  The history file is, in the restore-from-archive case,
> needed to *find* the xlog data.
> 
> However, it's not clear to me why SR should have any need for it.
> It's not doing restore from archive.

Definitely should not make this *just* in WAL, files still required,
agreed.

It's needed to find the place where the backup stopped, so it defines
the safe stopping point. We could easily pass that info via WAL, when
streaming. It doesn't actually matter until we try to failover.

-- Simon Riggs           www.2ndQuadrant.com