From: | "Joshua D(dot) Drake" <jd(at)commandprompt(dot)com> |
---|---|
To: | Andres Freund <andres(at)2ndquadrant(dot)com> |
Cc: | Heikki Linnakangas <hlinnakangas(at)vmware(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgreSQL(dot)org>, Peter Geoghegan <pg(at)heroku(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com> |
Subject: | Re: Hard limit on WAL space used (because PANIC sucks) |
Date: | 2013-06-08 20:26:56 |
Message-ID: | 51B39390.3040000@commandprompt.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On 06/08/2013 11:27 AM, Andres Freund wrote:
>
> On 2013-06-08 11:15:40 -0700, Joshua D. Drake wrote:
>> To me, a more pragmatic approach makes sense. Obviously having some kind of
>> code that checks the space makes sense but I don't know that it needs to be
>> around any operation other than we are creating a segment. What do we care
>> why the segment is being created? If we don't have enough room to create the
>> segment, the transaction rollsback with some OBVIOUS not OBTUSE error.
>>
>> Obviously this could cause a ton of transactions to roll back but I think
>> keeping the database consistent and rolling back a transaction in case of
>> error is exactly what we are supposed to do.
>
> You know, the PANIC isn't there just because we like to piss of
> users. There's actual technical reasons that don't just go away by
> judging the PANIC as stupid.
Yes I know we aren't trying to piss off users. What I am saying is that
it is stupid to the user that it PANICS. I apologize if that came out wrong.
> At the points where the XLogInsert()s happens we're in critical sections
> out of which we *cannot* ERROR out because we already may have made
> modifications that cannot be allowed to be performed
> partially/unlogged. That's why we're throwing a PANIC which will force a
> cluster wide restart including *NOT* writing any further buffers from
> s_b out.
>
Does this preclude (sorry I don't know this part of the code very well)
my suggestion of on log create?
JD
> Greetings,
>
> Andres Freund
>
From | Date | Subject | |
---|---|---|---|
Next Message | Joshua D. Drake | 2013-06-08 20:31:23 | small patch to crypt.c |
Previous Message | Jeff Janes | 2013-06-08 20:17:21 | Re: Cost limited statements RFC |