Re: TODO list

Andrew Dunstan wrote:
>
>
> Bruce Momjian wrote:
>
> >Andrew Dunstan wrote:
> >
> >
> >>I thought we had thrashed this out back in August. Certainly the only
> >>thing I recall seeing after I submitted the patch was some stylistic
> >>criticism from Neil, which I addressed in a revised patch.
> >>
> >>Anyway, it is in principle doable. That's partly why I adopted a printf
> >>style format string. There are some wrinkles, though:
> >>. interaction with syslog pid/timestamp logging
> >>
> >>
> >
> >Yes. If you use syslog, just don't ask for pid/timestamp and let syslog
> >do it. Of course, right now we are able to send non-pid/timestamp to
> >syslog _and_ send pid/timestamp to a log file, but that seems like a
> >rare operation that doesn't justify keeping the various log parameters
> >separate.
> >
>
>
>
> I'm OK with that as long as it is the consensus view. It does seem a
> little odd to remove functionality (however rare) for the sake of
> configuration neatness, though.

Yes, agreed. Let's explore it. The rare functionality we would be
removing is for:

o User uses syslog
o User wants to log postmaster output to a file too
o User wants timestamp info in the postmaster output file

And the downside is that they get duplicate timestamps in syslog.

Now, if we don't merge timestamp into your new per-line log string, we
end up with a rather illogical and inflexible output format, only to
allow the rare case listed above.

Clearly this isn't a 100% clear decision, but it seems to lean in the
direction of removing the functionality with the goal of providing a
more logical logging API to the users.

> >Also, I would like to see some kind of session identifier that is more
> >unique than pid, which wraps around. Ideally we could have 10{pid},
> >then then the pid wraps around, 20{pid), or something like that.
> >
>
>
> This requires some thought. ISTM it wouldn't buy you much unless you
> made it persistent across server restarts, and possibly not even then. I
> don't see it as a reason to hold up these features, though. If someone
> wants to tackle this it could be plugged in to the loginfo feature very
> easily as an extra escape sequence.

Yes, that was my idea --- let's get this in and we can then add a
session id, and your point about restarts is a good one.

> >>. making sure the info is available when you need to log it - I had to
> >>rearrange a few thing to avoid getting SEGVs, IIRC.
> >>
> >>
> >
> >Of course some messages, like postmaster status messages, don't have
> >some of these fields, like username or host. Is that going to cause
> >problems for tools that read our log files?
> >
>
>
> If users want a non-empty info string they will have to teach the tools
> to handle it anyway. The point was, however, that rolling up PID and
> timestamp into the printf-style format will require some significant
> work, because we wouldn't want to lose that info if the user/db weren't
> known, whereas the patch currently suppresses all log-info output if
> these are not present (i.e. when MyProcPort == NULL).

Oh, good point. That would suggest that maybe we are better off leaving
pid and timestamp as separate options and _not_ merge them into your new
string. I am starting to think having your string print only
session-specific information is the best way.

I wonder if we should rename your GUC log_session_line or something like
that.

> >>Also, the session duration logging part of the patch is orthogonal to the
> >>issue.
> >
> >You mean query duration? Yes, it is orthoginal.
>
> No, I meant the logging of the end of a session, including its duration,
> which was also in the patch.

Oh, I missed that one. It seems like a nice addition. I see you added
it when they ask for log_connections. Good idea.

--
Bruce Momjian | http://candle.pha.pa.us
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