Re: Data corruption issues using streaming replication on 9.0.14/9.2.5/9.3.1

On 2013-11-20 15:52:22 -0800, Josh Berkus wrote:
> Andres,
>
> > Everytime the server in HS mode allows connections ("consistent recovery state
> > reached at ..." and "database system is ready to accept read only
> > connections" in the log), the bug can be triggered. If there weren't too
> > many transactions at that point, the problem won't occur until the
> > standby is restarted.
>
> Oh, so this doesn't just happen when the base backup is first taken;
> *any* time the standby is restarted, it can happen. (!!!)

Yes.

> If you have any ideas for how we'd write code to scan for this kind of
> corruption, please post them.

I don't really have one. Current corruption would be somewhat easy to
detect (walk through the clog, check if all commit bits match), but that
doesn't detect wether already truncated clog was corrupted.

Greetings,

Andres Freund

--
Andres Freund http://www.2ndQuadrant.com/
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