Message-ID: <5358A38F.50808@2ndquadrant.com>
Date: Thu, 24 Apr 2014 13:39:27 +0800
From: Craig Ringer <craig@2ndquadrant.com>
Organization: 2nd Quadrant
User-Agent: Mozilla/5.0 (X11; Linux x86_64;
 rv:24.0) Gecko/20100101 Thunderbird/24.4.0
MIME-Version: 1.0
To: Petr Jelinek <petr@2ndquadrant.com>, Robert Haas <robertmhaas@gmail.com>,
 Andres Freund <andres@2ndquadrant.com>
CC: Tom Lane <tgl@sss.pgh.pa.us>, Antonin Houska <antonin.houska@gmail.com>,
 "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>,
 Abhijit Menon-Sen <ams@2ndQuadrant.com>
Subject: Re: bgworker crashed or not?
References: <20140416131052.GG17874@awork2.anarazel.de>
	<CA+TgmoYy2oJL7t-rknyVENm=vnqTTtb=R-TDkMsrMrgbhQDiew@mail.gmail.com>
	<20140416152803.GJ17874@awork2.anarazel.de>
	<CA+TgmoZPrzktkbwYRgv2fbhBi2_ty9BEtV6Gk-SSrERROZUkvw@mail.gmail.com>
	<20140416154412.GL17874@awork2.anarazel.de>	<27214.1397663665@sss.pgh.pa.us>
	<20140416160047.GM17874@awork2.anarazel.de>
	<CA+TgmoZe4zqRAX8rgpy9UWy=PE7=3B_1J34bTehEi25hCgr3kw@mail.gmail.com>
	<20140416161143.GN17874@awork2.anarazel.de>
	<CA+TgmoaefVEJeO7+D=VE35Aj2fkgZ3YVqWx8Svzd3v493iJSvg@mail.gmail.com>
	<20140416162837.GO17874@awork2.anarazel.de>
 <CA+TgmoZLwmkZ2O6T29qAb9EhO-9cyz4Rj9mjLQVkFe673CooWA@mail.gmail.com>
 <534EEC61.7000006@2ndquadrant.com> <534F21E6.7080705@2ndquadrant.com>
In-Reply-To: <534F21E6.7080705@2ndquadrant.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org

On 04/17/2014 08:35 AM, Craig Ringer wrote:
> On 04/17/2014 04:47 AM, Petr Jelinek wrote:
>>
>> Well the logging is just too spammy in general when it comes to dynamic
>> bgworkers but that's easy to fix in the future, no need to make
>> decisions for 9.4.
> 
> Agreed - it's the *API* that we need sorted out for 9.4, and log output
> isn't something Pg tends to consider part of the API.
> 
>> However I really don't like that I have to exit with exit code 1, which
>> is normally used as failure, if I want to shutdown my dynamic bgworker
>> once it has finished the work. And this behavior is something we can set
>> properly only once...
> 
> As far as I can tell we have a couple of options:
> 
> - Redefine what the exit codes mean so that exit 0 suppresses
> auto-restart and exits silently. Probably simplest.

I'm now strongly in favour of this alternative.

I've just noticed that the bgworker control interfaces do not honour
bgw.bgw_restart_time = BGW_NEVER_RESTART if you exit with status zero.

This means that it's not simply a problem where you can't say "restart
me if I crash, but not if I exit normally".

You also can't even say "never restart me at all". Because
"BGW_NEVER_RESTART" seems to really mean "BGW_NO_RESTART_ON_CRASH".

This _needs_fixing before 9.4.


-- 
 Craig Ringer                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services


-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers