Re: Redesigning checkpoint_segments

On Thu, Jun 6, 2013 at 10:00 AM, Joshua D. Drake <jd(at)commandprompt(dot)com>wrote:

>
> 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.
>
Here it is:
http://www.postgresql.org/message-id/CAM3SWZQcyNxvPaskr-pxm8DeqH7_qevW7uqbhPCsg1FpSxKpoQ@mail.gmail.com
--
Michael