On 2015-03-12 17:42:33 -0700, Peter Geoghegan wrote:
> On Thu, Mar 12, 2015 at 5:21 PM, Andres Freund <andres@2ndquadrant.com> wrote:
> > On 2015-03-12 16:42:24 -0700, Peter Geoghegan wrote:
> >> We want to create a new role when this happens, for various reasons.
> >> This occurs after recovery ends, but before the database has been
> >> "unfenced". The template code that generates various ALTER ROLE
> >> statements in our internal provisioning system - which has apparently
> >> worked just fine for a long time - is:
> >
> > Is this all the code that's exececuted after recovery? How are these
> > forks brought up? Promoted how? Is it a common 'source' database?
>
> We do PITR up to a recovery target.
So, no hot standby enabled?
> I'm not sure what other code might have already been run at this
> point, but it won't have been much.
> > Have you looked at these files? Are they indeed zero bytes when this
> > error occurs?
> I think that they are indeed zero. I looked at that last week, when I
> didn't consider that this might be a more widespread issue. I'll check
> again later.
> > Any chance that the new nodes also use a different kernel version or
> > such?
>
> They may differ, but that doesn't seem likely to be relevant, at least
> to me.
There've been some issues with seek(END) sometimes returning the wrong
length in the past. And I've seen a report that might indicate a similar
bug has been reintroduced. That could certainly cause such anerror.
> I am unfamiliar with this provisioning code, so, as I
> mentioned, offhand I cannot be entirely sure that there isn't some
> other code run when the problem originally arises (that I should have
> included in my report).
It's probably worthwhile to dig out what's happening.
> What I can tell you is that I saw the same error messages when I
> manually ran the statements generated by the above code within a
> transaction...until I ran "VACUUM FULL pg_auth_members;".
You can reproduce that problem? How easily? If you can, please produce a
backtrace. It'll certainly be interesting to see whether that access is
through an index or whatnot.
Greetings,
Andres Freund
-- Andres Freund http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services