Re: process type escape for log_line_prefix

Re: Michael Paquier 2016-02-10 <CAB7nPqS=wBbZzBcty1KyN-5Y9bPXZ+deJbfcCtebf06eF2Uyvg@mail.gmail.com>
> On Mon, Feb 8, 2016 at 11:32 PM, Andres Freund <andres@anarazel.de> wrote:
> > Frequently when reading postgres logs to do some post mortem analysis
> > I'm left wondering what process emitted an error/log message. After the
> > fact it's often hard to know wether an error message was emitted by a
> > user backend or by something internal, say the checkpointer or
> > autovacuum.  Logging all process starts is often impractical given the
> > log volume that causes.
> >
> > So I'm proposing adding an escape displaying the process title (say 'k'
> > for kind?). So %k would emit something like "autovacuum worker process",
> > "wal sender process" etc.
> 
> It would be nice to get something consistent between the ps output and
> this new prefix, say with for example a miscadmin.h parameter like
> MyProcName.
> 
> > I'm thinking it might make sense to give normal connections "" as the
> > name, they're usually already discernible.
> 
> Yeah, that sounds fine for me. What about background workers? I would
> think that they should use BackgroundWorker->bgw_name.

(Rediscovering an old horse)

Couldn't these processes just set %a = application_name? (This would
obviously need %q to be taught that %a is always valid.)

Christoph