Re: libpq debug log

On Tue, Oct 30, 2018 at 8:38 PM Iwata, Aya <iwata.aya@jp.fujitsu.com> wrote:

> Hi,
>
> I create a first libpq trace log patch.
>
> In this patch,
> - All message that PQtrace() gets are output to the libpq trace log file
>   (I maybe select more effective message in the future patch)
> - Trace log output style is changed slightly from previously proposed
>
> This patch not include documentation,
> but you can see parameter detail and how to use it by looking at my
> previous e-mail.
>
>  If get the trace log, set PGLOGDIR/logdir and PGLOGSIZE/logsize.
>  These parameters are set in the environment variable or the connection
> service
>  file.
>  - logdir or PGLOGDIR : directory where log file written
>  - logsize or PGLOGSIZE : maximum log size(M). When the log file size
> exceeds to
>  PGLOGSIZE, the log is output to another file.
>
>  The log file name is determined as follow.
>  libpq-%ProcessID-%Y-%m-%d_%H%M%S.log
>
> Trace log example;
> Start :  2018/10/30 08:02:24.433
> ... time(a)
> Query: SELECT pg_catalog.set_config('search_path', '', false)
> To backend> Msg Q
> To backend> "SELECT pg_catalog.set_config('search_path', '', false)"
> To backend> Msg complete, length 60
> Start sending message to backend:  2018/10/30 08:02:24.433
> ... time(b)
> End sending message to backend:  2018/10/30 08:02:24.433
> ... time(c)
> Start receiving message from backend:  2018/10/30 08:02:24.434  ... time(d)
> End receiving message from backend:  2018/10/30 08:02:24.434    ... time(e)
> From backend> T
> From backend (#4)> 35
> From backend (#2)> 1
> From backend> "set_config"
> From backend (#4)> 0
> From backend (#2)> 0
> From backend (#4)> 25
> From backend (#2)> 65535
> From backend (#4)> -1
> From backend (#2)> 0
> From backend> D
> From backend (#4)> 10
> From backend (#2)> 1
> From backend (#4)> 0
> From backend> C
> From backend (#4)> 13
> From backend> "SELECT 1"
> From backend> Z
> From backend (#4)> 5
> From backend> Z
> From backend (#4)> 5
> From backend> I
> End :  2018/10/30 08:02:24.435                                  ... time(f)
>
> From time(a) to time(b): time for libpq processing
> From time(b) to time(c): time for traffic
> From time(c) to time(d): time for backend processing
> From time(d) to time(e): time for traffic
> From time(e) to time(f): time for libpq processing
>

Thanks for the patch.

I have some comments related to the trace output that is getting
printed. The amount of log it is generating may not be understood
to many of the application developers. IMO, this should print
only the necessary information that can understood by any one
by default and full log with more configuration?

Regards,
Haribabu Kommi
Fujitsu Australia