Re: Add jsonlog log_destination for JSON server logs

Michael Paquier <michael@paquier.xyz>

From: Michael Paquier <michael@paquier.xyz>
To: Andrew Dunstan <andrew@dunslane.net>
Cc: Sehrope Sarkuni <sehrope@jackdb.com>, Pg Hackers <pgsql-hackers@postgresql.org>, david@fetter.org
Date: 2021-09-09T02:17:01Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Introduce log_destination=jsonlog

  2. Refactor set of routines specific to elog.c

  3. Fix compilation warning in syslogger.c

  4. Refactor per-destination file rotation in logging collector

  5. Refactor output file handling when forking syslogger under EXEC_BACKEND

  6. Add regression tests for csvlog with the logging collector

  7. Refactor the syslogger pipe protocol to use a bitmask for its options

Attachments

On Wed, Sep 08, 2021 at 08:46:44AM -0400, Andrew Dunstan wrote:
> Yeah. A very simple change would be to use two different values for json
> (say 'y' and 'n'). A slightly more principled scheme might use the top
> bit for the end marker and the bottom 3 bits for the dest type (so up to
> 8 types possible), with the rest available for future use.

I was thinking to track stderr as a case where no bits are set in the
flags for the area of the destinations, but that's a bit crazy if we
have a lot of margin in what can be stored.  I have looked at that and
finished with the attached which is an improvement IMO, especially
when it comes to the header validation.

FWIW, while looking at my own external module for the JSON logs, I
noticed that I used the chunk protocol when the log redirection is
enabled, but just enforced everything to be sent to stderr.
--
Michael