Horton

Re: SLRU statistics

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Fujii Masao <masao.fujii@oss.nttdata.com>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Masahiko Sawada <masahiko.sawada@2ndquadrant.com>, "tsunakawa.takay@fujitsu.com" <tsunakawa.takay@fujitsu.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2020-05-14T02:24:48Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Fix async.c to not register any SLRU stats counts in the postmaster.

  2. Use proper GetDatum function in pg_stat_get_slru().

  3. Initialize SLRU stats entries to zero.

  4. Remove pg_xact from pg_stat_reset_slru docs

  5. Remove pg_xact entry from SLRU stats

  6. Track SLRU page hits in SimpleLruReadPage_ReadOnly

  7. Fix typo in SLRU stats documentation

  8. Collect statistics about SLRU caches

  9. Simplify and rename some GUC variables, per various recent discussions:

Fujii Masao <masao.fujii@oss.nttdata.com> writes:
> On 2020/05/14 2:44, Tom Lane wrote:
>> I got through check-world with the assertion shown that we are not
>> counting any SLRU operations in the postmaster.  Don't know if we
>> want to commit that or not --- any thoughts?

> +1 to add this assertion because basically it's not good thing
> to access to SLRU at postmaster and we may want to fix that if found.
> At least if we get rid of the SLRUStats initialization code,
> IMO it's better to add this assertion and ensure that postmaster
> doesn't update the SLRU stats counters.

Seems reasonable --- I'll include it.

It might be nice to have similar assertions protecting BgWriterStats.
But given that we've made that public to be hacked on directly by several
different modules, I'm not sure that there's any simple way to do that.

			regards, tom lane