Re: Add jsonlog log_destination for JSON server logs

On Tue, Aug 31, 2021 at 11:34:56AM -0400, Sehrope Sarkuni wrote:
> The second commit adds a TAP test for log_destination "csvlog". This was
> done to both confirm that the previous change didn't break anything and as
> a skeleton for the test in the next commit.

+note "Before sleep";
+usleep(100_000);
+note "Before rotate";
+$node->logrotate();
+note "After rotate";
+usleep(100_000);

Do you really need a rotation of the log files here?  Wouldn't it be
better to grab the position of the current log file with a fixed log
file name, and then slurp the file from this position with your
expected output?  That would make the test faster, as well.

Rather than making elog.c larger, I think that we should try to split
that into more files.  Why not refactoring out the CSV part first?
You could just call that csvlog.c, then create a new jsonlog.c for the
meat of the patch.

The list of fields is not up to date.  At quick glance, you are
missing:
- backend type.
- leader PID.
- query ID.
- Session start timestamp (?)