| From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
|---|---|
| To: | Simon Riggs <simon(at)2ndquadrant(dot)com> |
| Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Fujii Masao <masao(dot)fujii(at)gmail(dot)com>, Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>, Stefan Kaltenbrunner <stefan(at)kaltenbrunner(dot)cc>, Andres Freund <andres(at)anarazel(dot)de>, Florian Pflug <fgp(at)phlo(dot)org>, Dimitri Fontaine <dfontaine(at)hi-media(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>, Bruce Momjian <bruce(at)momjian(dot)us>, Greg Smith <greg(at)2ndquadrant(dot)com>, Josh Berkus <josh(at)agliodbs(dot)com> |
| Subject: | Re: Stefan's bug (was: max_standby_delay considered harmful) |
| Date: | 2010-05-19 13:03:19 |
| Message-ID: | AANLkTikNSTliNzAoObAR-cUflQHCGmVgjYFYfzyVdLP2@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Wed, May 19, 2010 at 8:49 AM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
> On Wed, 2010-05-19 at 08:21 -0400, Tom Lane wrote:
>> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> > On Wed, May 19, 2010 at 1:47 AM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
>> >> Yes, but I prefer XLogCtl->SharedRecoveryInProgress, which is the almost
>> >> same indicator as the boolean you suggested. Thought?
>>
>> > It feels cleaner and simpler to me to use the information that the
>> > postmaster already collects rather than having it take locks and check
>> > shared memory, but I might be wrong. Why do you prefer doing it that
>> > way?
>>
>> The postmaster must absolutely not take locks (once there are competing
>> processes). This is non negotiable from a system robustness standpoint.
>
> Masao has not proposed this, in fact his proposal was to deliberately
> avoid do so.
>
> I proposed using the state recorded in xlog.c rather than attempting to
> duplicate that with a second boolean in postmaster because that seems
> likely to be more buggy.
Well then how are we reading XLogCtl?
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise Postgres Company
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Stefan Kaltenbrunner | 2010-05-19 14:17:08 | Re: BYTEA / DBD::Pg change in 9.0 beta |
| Previous Message | Boszormenyi Zoltan | 2010-05-19 12:58:31 | Re: Synchronous replication patch built on SR |