Horton

Re: Berserk Autovacuum (let's save next Mandrill)

Darafei Komяpa Praliaskouski <me@komzpa.net>

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From: Darafei "Komяpa" Praliaskouski <me@komzpa.net>
To: David Rowley <david.rowley@2ndquadrant.com>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2019-03-28T09:03:47Z
Lists: pgsql-hackers 
On Thu, Mar 28, 2019 at 2:36 AM David Rowley <david.rowley@2ndquadrant.com>
wrote:

> On Thu, 28 Mar 2019 at 11:01, Alvaro Herrera <alvherre@2ndquadrant.com>
> wrote:
> >
> > On 2019-Mar-28, Darafei "Komяpa" Praliaskouski wrote:
> > > "Nearing wraparound" is too late already. In Amazon, reading table
> from gp2
> > > after you exhausted your IOPS burst budget is like reading a floppy
> drive,
> > > you have to freeze a lot earlier than you hit several terabytes of
> unfrozen
> > > data, or you're dead like Mandrill's Search and Url tables from the
> link I
> > > shared.
> >
> > OK, then start freezing tuples in the cheap mode (skip index updates)
> > earlier than that.  I suppose a good question is when to start.
>
> I thought recently that it would be good to have some sort of
> pro-active auto-vacuum mode that made use of idle workers.


Problem with "idle" is that it never happens on system that are going to
wraparound on their lifetime. This has to be a part of normal database
functioning.

Why not select a table that has inserts, updates and deletes for autovacuum
just like we do for autoanalyze, not only deletes and updates like we do
now?


-- 
Darafei Praliaskouski
Support me: http://patreon.com/komzpa

Commits

  1. Further improve stability fix for partition_aggregate test.

  2. Improve stability fix for partition_aggregate test.

  3. Attempt to stabilize partitionwise_aggregate test

  4. Fix race condition in statext_store().

  5. Attempt to fix unstable regression tests, take 2

  6. Attempt to fix unstable regression tests

  7. Trigger autovacuum based on number of INSERTs

  8. Fix upper limit for vacuum_cleanup_index_scale_factor