Re: SLRU statistics

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

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: 2020-05-13T17:44:44Z

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 →

Fix async.c to not register any SLRU stats counts in the postmaster.
- 7fd89f4d7a51 13.0 landed
Use proper GetDatum function in pg_stat_get_slru().
- 043e3e040160 13.0 landed
Initialize SLRU stats entries to zero.
- f3d23d83ef9a 13.0 landed
Remove pg_xact from pg_stat_reset_slru docs
- e685ca63ca4f 13.0 landed
Remove pg_xact entry from SLRU stats
- 2e08d314ed07 13.0 landed
Track SLRU page hits in SimpleLruReadPage_ReadOnly
- 2b88fdde30d8 13.0 landed
Fix typo in SLRU stats documentation
- 2c220ca46f3f 13.0 landed
Collect statistics about SLRU caches
- 28cac71bd368 13.0 landed
Simplify and rename some GUC variables, per various recent discussions:
- 48f7e6439568 8.3.0 cited

Attachments

dont-do-slru-ops-in-postmaster.patch (text/x-diff) patch

I wrote:
>>> (IIRC only the Async module is doing that.)

> Hm, maybe we can fix that.

Yeah, it's quite easy to make async.c postpone its first write to the
async SLRU.  This seems like a win all around, because many installations
don't use NOTIFY and so will never need to do that work at all.  In
installations that do use notify, this costs an extra instruction or
two per NOTIFY, but that's down in the noise.

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?

			regards, tom lane