Thread: Limiting the size of log files

On 18 August 2010 08:52, Amit Soni <get.amitsoni@gmail.com> wrote:
> Hi,
> I want to limit the size of the log files since it's going into GB's. I used
> the option "log_rotation_size = 1024" but the size went much ahead the
> specified 1MB.

Did you "reload" PostgreSQL after you changed that option?

--
Thom Brown
Registered Linux user: #516935

On 18 August 2010 10:14, Amit Soni <get.amitsoni@gmail.com> wrote:
> @Thom: Yes, I restarted the postgresql service, that's how I got the
> configuration in the pg_settings table. I even rebooted the machine just to
> be sure.
>

Please copy in the group in your responses otherwise only I can see
your replies.

Ah of course, that's kind of obvious that you did the reload.  Apologies.

What is the name of the lastest log file it's emitted and what size was it?

--
Thom Brown
Registered Linux user: #516935

On 18 August 2010 10:32, Amit Soni <get.amitsoni@gmail.com> wrote:
> Sorry for not copying the group in my previous response. The name of the
> largest and the only log file is "postgresql.log" and its size is 32900151B
> (32M) with the current settings.
>

I believe it might be because you haven't set up a pattern for the
filename, you've just specified a plain name.

So change log_filename from "postgresql.log" to "postgresql-%Y-%m-%d_%H%M%S.log"

--
Thom Brown
Registered Linux user: #516935

On 18 August 2010 10:54, Amit Soni <get.amitsoni@gmail.com> wrote:
> I tried this and the limit on the log file size works.
> The reason I didn't tried this before is that, I would probably have GB's of
> logs and the space consumed on the disk would be same in this case also with
> only difference in the number of file. Do we have some kind of pattern that
> would repeat itself so that we can have let's say only five log files which
> rotate themselves.
>

Yes, you can set "log_truncate_on_rotation" to "on" and adjust the
filename pattern.  However, I'd recommend not using size-based
rotation, but rather time-based.

So change:

log_filename to "postgresql-%H"
log_rotation_age to 60
log_rotation_size to 0

The log files will start being rotated after 24 hours as it will start
overwriting previous hours.

However, I'm not entirely sure how PostgreSQL decides to rotate "after
60 minutes".  If you start PostgreSQL at, say, 12:44, it would create:

postgresql-12.sql

At 13:44 I guess it would say "I need to rotate", so creates:

postgresql-13,.sql

So postgresql-12.sql contains log entries from 12:44 to 13:43.  If
this is the case, just bear it in mind and don't assume something like
"postgresql-15.sql" contains log entries from 15:00:00 to 15:59:59.

--
Thom Brown
Registered Linux user: #516935

On 18 August 2010 11:34, Amit Soni <get.amitsoni@gmail.com> wrote:
> Sorry for not stating this earlier. It's possible for me to have ~20GB of
> logs in one day. So, per day rotation is not the best option here. And since
> limiting the size of the file is only possible when we use some time related
> pattern in the filename (which I should have deduced from
> "log_truncate_on_rotation" not working on the size driven rotation), I see
> the chances of getting what I need as very slim.
> Any other suggestion would be greatly appreciated.
> Thanks & Regards,
> Amit
>

Just change it so that it wraps after an hour then:

log_filename to "postgresql-%M.log"
log_rotation_age to 1
log_rotation_size to 0
log_truncate_on_rotation to on

Or just go back to "postgresql.log" and use a separate log rotator to
do the task for you, like logrotate.

--
Thom Brown
Registered Linux user: #516935

Le Wed, 18 Aug 2010 16:04:14 +0530,
Amit Soni <get.amitsoni@gmail.com> a écrit :

> Sorry for not stating this earlier. It's possible for me to have ~20GB of
> logs in one day. So, per day rotation is not the best option here. And

may be checking/modifying (in postgresql.conf):
    client_min_messages
    log_min_messages
    log_error_verbosity
    log_min_error_statement
end "debug_print_xxx" lines too

looks like you turned a debug logging on and didn't switched it off.

JY
--

Amit Soni wrote:
> I want to limit the size of the log files since it's going into GB's.


Perhaps you should log fewer events.  See the "When to Log" section of
postgresql.conf