Horton

Re: Testing autovacuum wraparound (including failsafe)

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: pgsql-hackers@postgresql.org, Peter Geoghegan <pg@bowt.ie>
Date: 2021-04-23T23:26:17Z
Lists: pgsql-hackers 
Hi,

On 2021-04-23 18:08:12 -0500, Justin Pryzby wrote:
> On Fri, Apr 23, 2021 at 01:43:06PM -0700, Andres Freund wrote:
> > 2) FAILSAFE_MIN_PAGES is 4GB - which seems to make it infeasible to test the
> >    failsafe mode, we can't really create 4GB relations on the BF. While
> >    writing the tests I've lowered this to 4MB...
> 
> > For 2), I don't really have a better idea than making that configurable
> > somehow?
> 
> Does it work to shut down the cluster and create the .0,.1,.2,.3 segments of a
> new, empty relation with zero blocks using something like truncate -s 1G ?

I'd like this to be portable to at least windows - I don't know how well
that deals with sparse files. But the bigger issue is that that IIRC
will trigger vacuum to try to initialize all those pages, which will
then force all that space to be allocated anyway...

Greetings,

Andres Freund

Commits

  1. Fix meson installation of xid_wraparound test.

  2. Add tests for XID wraparound.

  3. Add option to specify timeout seconds to BackgroundPsql.pm.

  4. Fix wrong description of BackgroundPsql's timeout.

  5. Refactor background psql TAP functions

  6. Consider triggering VACUUM failsafe during scan.

  7. Fix autovacuum log output heap truncation issue.