Re: Strange issues with 9.2 pg_basebackup & replication - Mailing list pgsql-hackers

From Joshua Berkus
Subject Re: Strange issues with 9.2 pg_basebackup & replication
Date
Msg-id 8352689.301373.1337258559392.JavaMail.root@mail-1.01.com
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In response to Re: Strange issues with 9.2 pg_basebackup & replication  (Jim Nasby <jim@nasby.net>)
Responses Re: Strange issues with 9.2 pg_basebackup & replication
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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@agliodbs.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@nasby.net
> 512.569.9461 (cell)                         http://jim.nasby.net
> 


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