Re: widen vacuum buffer counters - Mailing list pgsql-hackers

From Julien Rouhaud
Subject Re: widen vacuum buffer counters
Date
Msg-id CAOBaU_YxtFrVp5PHNjeEdd05o9XUaAuF_P+Y_+NuBOoZBemq5w@mail.gmail.com
Whole thread Raw
In response to widen vacuum buffer counters  (Alvaro Herrera <alvherre@2ndquadrant.com>)
List pgsql-hackers
On Fri, Jan 31, 2020 at 9:59 PM Alvaro Herrera <alvherre@2ndquadrant.com> wrote:
>
> We recently noticed that vacuum buffer counters wraparound in extreme
> cases, with ridiculous results.  Example:
>
> 2020-01-06 16:38:38.010 EST [45625-1] app= LOG:  automatic vacuum of table "somtab.sf.foobar": index scans: 17
>         pages: 0 removed, 207650641 remain, 0 skipped due to pins, 13419403 skipped frozen
>         tuples: 141265419 removed, 3186614627 remain, 87783760 are dead but not yet removable
>         buffer usage: -2022059267 hits, -17141881 misses, 1252507767 dirtied
>         avg read rate: -0.043 MB/s, avg write rate: 3.146 MB/s
>         system usage: CPU 107819.92s/2932957.75u sec elapsed 3110498.10 sec
>
> That's to be expected, as tables exist that are large enough for 4 billion
> buffer accesses to be a possibility.  Let's widen the counters, as in the
> attached patch.
>
> I propose to backpatch this.

+1, and patch LGTM.



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