Re: Patch to implement pg_current_logfile() function

From: "Karl O(dot) Pinc" <kop(at)meme(dot)com>
To: Gilles Darold <gilles(dot)darold(at)dalibo(dot)com>
Cc: Christoph Berg <myon(at)debian(dot)org>, Michael Paquier <michael(dot)paquier(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, "Shulgin, Oleksandr" <oleksandr(dot)shulgin(at)zalando(dot)de>, Robert Haas <robertmhaas(at)gmail(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Patch to implement pg_current_logfile() function
Date: 2016-11-02 02:51:57
Message-ID: 20161101215157.32db7206@slate.meme.com
Views: Raw Message | Whole Thread | Download mbox
Thread:
Lists: pgsql-hackers

On Mon, 31 Oct 2016 09:26:27 +0100
Gilles Darold <gilles(dot)darold(at)dalibo(dot)com> wrote:

> Le 30/10/2016 à 08:04, Karl O. Pinc a écrit :

> Attached patch v11 include your patch.
>
> >
> > I have some questions about logfile_writename():
> >
> > Why does the logfile_open() call fail silently?

> logfile_open() "fail silently" in logfile_writename(), like in other
> parts of syslogger.c where it is called, because this is a function()
> that already report a message when an error occurs ("could not open
> log file..."). I think I have already replied to this question.

Please apply the attached patch on top of your v11 patch.
It simulates a logfile_open() failure. Upon simulated failure you do
not get a "currrent_logfile" file, and neither do you get any
indication of any problems anywhere in the logs. It's failing
silently.

To test I create a cluster, start the server, and look for
current_logfile and at the logs.

(I finally got around to writing down the process I use to install
and run a patched server, instead of just poking it with a
stick until it works every time I get back to hacking pg.
I'd be happy to share my process with you
if you're interested. If you cannot reproduce my results please
share with me your procedure for cluster creation and runtime testing
so I can see why I find a problem and you don't. Thank you.)

I don't expect to have a lot of time to work on pg in the next
36 hours. After that I hope to push this through to completion.
I did want to get something back to you now, hence this email.

Regards,

Karl <kop(at)meme(dot)com>
Free Software: "You don't pay back, you pay forward."
-- Robert A. Heinlein

Attachment Content-Type Size
patch_pg_current_logfile-v11.diff.silentfail application/octet-stream 508 bytes

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Amit Langote 2016-11-02 02:55:51 Re: Declarative partitioning - another take
Previous Message David Rowley 2016-11-02 02:21:28 Re: Performance improvement for joins where outer side is unique