Horton

Re: Improving connection scalability: GetSnapshotData()

Ian Barwick <ian.barwick@2ndquadrant.com>

View thread View on postgr.es
From: Ian Barwick <ian.barwick@2ndquadrant.com>
To: Andres Freund <andres@anarazel.de>, andrew@dunslane.net
Cc: Michael Paquier <michael@paquier.xyz>, Tom Lane <tgl@sss.pgh.pa.us>, Robert Haas <robertmhaas@gmail.com>, Thomas Munro <thomas.munro@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Daniel Gustafsson <daniel@yesql.se>, "Jonathan S. Katz" <jkatz@postgresql.org>, Alexander Korotkov <a.korotkov@postgrespro.ru>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Peter Geoghegan <pg@bowt.ie>, Bruce Momjian <bruce@momjian.us>, David Rowley <dgrowleyml@gmail.com>
Date: 2020-10-02T02:14:19Z
Lists: pgsql-hackers 
On 2020/10/02 3:26, Andres Freund wrote:
> Hi Ian, Andrew, All,
> 
> On 2020-09-30 15:43:17 -0700, Andres Freund wrote:
>> Attached is an updated version of the test (better utility function,
>> stricter regexes, bailing out instead of failing just the current when
>> psql times out).  I'm leaving it in this test for now, but it's fairly
>> easy to use this way, in my opinion, so it may be worth moving to
>> PostgresNode at some point.
> 
> I pushed this yesterday. Ian, thanks again for finding this and helping
> with fixing & testing.

Thanks! Apologies for not getting back to your earlier responses,
have been distracted by Various Other Things.

The tests I run which originally triggered the issue now run just fine.


Regards

Ian Barwick


-- 
Ian Barwick                   https://www.2ndQuadrant.com/
  PostgreSQL Development, 24x7 Support, Training & Services

Commits

  1. Try to unbreak 021_row_visibility.pl on mingw.

  2. Fix and test snapshot behavior on standby.

  3. Fix race condition in snapshot caching when 2PC is used.

  4. snapshot scalability: cache snapshots using a xact completion counter.

  5. Fix use of wrong index in ComputeXidHorizons().

  6. Make vacuum a bit more verbose to debug BF failure.

  7. snapshot scalability: Introduce dense array of in-progress xids.

  8. snapshot scalability: Move PGXACT->vacuumFlags to ProcGlobal->vacuumFlags.

  9. snapshot scalability: Move subxact info to ProcGlobal, remove PGXACT.

  10. snapshot scalability: Move PGXACT->xmin back to PGPROC.

  11. snapshot scalability: Don't compute global horizons while building snapshots.

  12. BRIN: Handle concurrent desummarization properly

  13. Track latest completed xid as a FullTransactionId.

  14. Rename VariableCacheData.nextFullXid to nextXid.

  15. snapshot scalability: Move delayChkpt from PGXACT to PGPROC.

  16. Report progress of CREATE INDEX operations