Re: Redesigning checkpoint_segments

From: "Joshua D(dot) Drake" <jd(at)commandprompt(dot)com>
To: Robert Haas <robertmhaas(at)gmail(dot)com>
Cc: Fujii Masao <masao(dot)fujii(at)gmail(dot)com>, Heikki Linnakangas <hlinnakangas(at)vmware(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Redesigning checkpoint_segments
Date: 2013-06-06 01:00:53
Message-ID: 51AFDF45.7080903@commandprompt.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers


On 06/05/2013 05:37 PM, Robert Haas wrote:
>
> On Wed, Jun 5, 2013 at 3:24 PM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
>> OTOH, if we use max_wal_size as a hard limit, we can avoid such PANIC
>> error and long down time. Of course, in this case, once max_wal_size is
>> reached, we cannot complete any query writing WAL until the checkpoint
>> has completed and removed old WAL files. During that time, the database
>> service looks like down from a client, but its down time is shorter than the
>> PANIC error case. So I'm thinking that some users might want the hard
>> limit of pg_xlog size.
>
> I wonder if we could tie this in with the recent proposal from the
> Heroku guys to have a way to slow down WAL writing. Maybe we have
> several limits:

I didn't see that proposal, link? Because the idea of slowing down
wal-writing sounds insane.

JD

--
Command Prompt, Inc. - http://www.commandprompt.com/ 509-416-6579
PostgreSQL Support, Training, Professional Services and Development
High Availability, Oracle Conversion, Postgres-XC, @cmdpromptinc
For my dreams of your image that blossoms
a rose in the deeps of my heart. - W.B. Yeats

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Michael Paquier 2013-06-06 01:10:57 Re: Redesigning checkpoint_segments
Previous Message Robert Haas 2013-06-06 00:43:03 Re: MVCC catalog access