Re: Config reload/restart preview

On Thu, Jun 20, 2013 at 4:34 PM, Thom Brown <thom(at)linux(dot)com> wrote:

> Hi,
>
> I've noticed that there's no easy way of checking which settings will
> change if the config is reloaded, and I think not being able to do this can
> cause some unfortunate problems.
>
> For example, a customer went to change their configuration, just setting
> log_autovacuum_min_duration to about 20 seconds, and reloaded the server.
> However, the log file swelled to over 5GB in size before they realised
> something was wrong, and then reverted the change. It transpired that the
> reload also pulled in a log_statements change from 'ddl' to 'all' that
> someone must have changed at some point without applying it.
>
> Should we have a way of previewing changes that would be applied if we
> reloaded/restarted the server?
>
> For example:
>
> pg_ctl previewconfig
>
> SIGHUP: log_statements will change from 'ddl' to 'all'
> SIGHUP: log_vacuum_min_duration will change from -1 to 20000
> POSTMASTER: fsync will change from 'on' to 'off'
>
> I'm not proposing this specifically, but something that would provide such
> information.
>
>
May be we can have a nice little utility which can show configuration diff
between two running servers, or a running server and its modified conf file
?

Thanks,
Pavan

--
Pavan Deolasee
http://www.linkedin.com/in/pavandeolasee