Thread: How to clear log files

How to clear log files

From

"Campbell, Lance"

Date:

03 February 2010, 20:27:53

PostgreSql:8.4.1

Is there a way for me to tell postgres to clear the log file. Example: I have log files created with names corresponding to the days of the week. This way they overwrite each other every week. When I deploy software enhancements I would like to clear the log file for the day without having to stop postgres. This way anything I see I know was after the deployment of my enhancements. I tried to just delete the file with postgres running. I found that it did not recreate the log file so I was forced to restart postgres.

Is there a command that might clear a log file or force it to rotate?

Thanks,

Lance Campbell

Software Architect/DBA/Project Manager

Web Services at Public Affairs

217-333-0382

Re: How to clear log files

From

Scott Mead

Date:

03 February 2010, 20:39:08

On Wed, Feb 3, 2010 at 4:12 PM, Campbell, Lance <lance@illinois.edu> wrote:

PostgreSql:8.4.1
Is there a way for me to tell postgres to clear the log file. Example: I have log files created with names corresponding to the days of the week. This way they overwrite each other every week. When I deploy software enhancements I would like to clear the log file for the day without having to stop postgres. This way anything I see I know was after the deployment of my enhancements. I tried to just delete the file with postgres running. I found that it did not recreate the log file so I was forced to restart postgres.

Is there a command that might clear a log file or force it to rotate?

You should be able to set 'log_truncate_on_rotation=on' in postgresql.conf and then run:

select pg_rotate_logfile();

That should rotate it, and if you have your log_filename setup with day of week only, it should truncate and restart in the same logfile. Haven't tested it, so I may be wrong, but it's worth a shot.

--Scott

Re: How to clear log files

From

"Plugge, Joe R."

Date:

03 February 2010, 20:43:07

What platform? If in Unix/Linux, just:

cat /dev/null > postgres_logfile

or > postgres_logfile

Most running programs don’t like it when you delete a file with an open file handle but you it doesn’t mind if you clear it on the fly. Not sure how to do this in a Windows environment.

From: pgsql-admin-owner@postgresql.org [mailto:pgsql-admin-owner@postgresql.org] On Behalf Of Campbell, Lance
Sent: Wednesday, February 03, 2010 3:13 PM
To: pgsql-admin@postgresql.org
Subject: [ADMIN] How to clear log files

PostgreSql:8.4.1

Is there a command that might clear a log file or force it to rotate?

Thanks,

Lance Campbell

Software Architect/DBA/Project Manager

Web Services at Public Affairs

217-333-0382

Re: How to clear log files

From

Gabriel Parrondo

Date:

03 February 2010, 23:56:30

El mié, 03-02-2010 a las 15:12 -0600, Campbell, Lance escribió:
> PostgreSql:8.4.1
>
> Is there a way for me to tell postgres to clear the log file.
> Example:  I have log files created with names corresponding to the
> days of the week.  This way they overwrite each other every week.
> When I deploy software enhancements I would like to clear the log file
> for the day without having to stop postgres.  This way anything I see
> I know was after the deployment of my enhancements.  I tried to just
> delete the file with postgres running.  I found that it did not
> recreate the log file so I was forced to restart postgres.
>
Actually, when you delete an opened file it isn't really deleted.
Whatever program opened it can still read/write to it using the file
descriptor.

> Is there a command that might clear a log file or force it to rotate?
Truncating it like this should work:
echo > /path/to/logfile

There's probably a better way though.