Re: Strange issues with 9.2 pg_basebackup & replication

Jim, Fujii,

Even more fun:

1) Set up a server as a cascading replica (e.g. max_wal_senders = 3, standby_mode = on )

2) Connect the server to *itself* as a replica.

3) This will work and report success, up until you do your first write.

4) Then ... segfault!

----- Original Message -----
> On 5/16/12 10:53 AM, Fujii Masao wrote:
> > On Wed, May 16, 2012 at 3:43 AM, Joshua Berkus<josh(at)agliodbs(dot)com>
> > wrote:
> >>
> >>> Before restarting it, you need to do pg_basebackup and make a
> >>> base
> >>> backup
> >>> onto the standby again. Since you started the standby without
> >>> recovery.conf,
> >>> a series of WAL in the standby has gotten inconsistent with that
> >>> in
> >>> the master.
> >>> So you need a fresh backup to restart the standby.
> >>
> >> You're not understanding the bug. The problem is that the standby
> >> came up and reported that it was replicating OK, when clearly it
> >> wasn't.
> >
> >> 8. Got this fatal error on the standby server:
> >>
> >> LOG: record with incorrect prev-link 0/70000B8 at 0/70000E0
> >> LOG: record with incorrect prev-link 0/70000B8 at 0/70000E0
> >>
> >> ... this error message repeated every 5s.
> >
> > According to your first report, ISTM you got error messages.
>
> Only *after* it was correctly setup.
>
> Josh's point is that if you flub the configuration, you should get an
> error, which is not what's happening now. Right now it just comes up
> and acts as if nothing's wrong.
> --
> Jim C. Nasby, Database Architect jim(at)nasby(dot)net
> 512.569.9461 (cell) http://jim.nasby.net
>