Re: Stefan's bug (was: max_standby_delay considered harmful)

Fujii Masao <masao.fujii@gmail.com>

From: Fujii Masao <masao.fujii@gmail.com>

To: Robert Haas <robertmhaas@gmail.com>

Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>, Simon Riggs <simon@2ndquadrant.com>, Andres Freund <andres@anarazel.de>, Florian Pflug <fgp@phlo.org>, Dimitri Fontaine <dfontaine@hi-media.com>, Tom Lane <tgl@sss.pgh.pa.us>, pgsql-hackers <pgsql-hackers@postgresql.org>, Bruce Momjian <bruce@momjian.us>, Greg Smith <greg@2ndquadrant.com>, Josh Berkus <josh@agliodbs.com>

Date: 2010-05-19T05:47:35Z

Lists: pgsql-hackers

On Wed, May 19, 2010 at 12:59 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> In terms of removing the backup label file, can we simply have an
> additional boolean in the postmaster that indicates whether we've ever
> reached PM_RUN, and only consider removing the backup file if so?

Yes, but I prefer XLogCtl->SharedRecoveryInProgress, which is the almost
same indicator as the boolean you suggested. Thought?

>>>> ISTM that walreceiver might be invoked even after shutdown is requested.
>>>> We should prevent the postmaster from starting up walreceiver if
>>>> Shutdown > NoShutdown?
>>>
>>> Well, when we did the previous shutdown patch, we decided it was not
>>> right to kill walreceiver until all backends had exited, so it seems
>>> inconsistent to make the opposite decision here.
>>
>> Oh, right. How about allowing the postmaster only in PM_STARTUP,
>> PM_RECOVERY, PM_HOT_STANDBY or PM_WAIT_READONLY state to invoke
>> walreceiver? We can keep walreceiver alive until all read only
>> backends have gone, and prevent unexpected startup of walreceiver.
>
> Yes, that seems like something we should be checking, if we aren't already.

I'll do that.

Regards,

-- 
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center