Improve logging

[group-butler]

Improve logging

[NotAFile]

I personally value at least having an option of human-readable logs a lot.

[yangm97]

So what about this:

Make a customisable log function/module with levels mimicking ngx.log ones. In config you could set where and how you want the logs delivered: stdout (either json or human), telegram, prometheus, etc.

[NotAFile]

Yeah, most coventional logging libraries allow you to plug long handlers that do different things with the logs, e.g. print them, email them, transmit them.

What twisted does, which I really really like is the following:

log.error("new group {groupname}, {membercount}", name="whatever", membercount=34)

That way, you can have both human and machine readable logs at the same time. You can set up different handlers for these messages then.

More generally, I think it's a mistake to take things that make sense on a large e.g. facebook or netflix scale and try to emulate it "just because". JSON logs, ELK stack etc. probably doesn't make sense for most GB deployments, the official one even, where there is a single server, single process, and a "grep" command can search it in less than a millisecond.

[yangm97]

I think dendrite has some kind of middle ground logging too, somewhat like this:

time="2018-06-23T16:15:41.788287481Z" level=warning msg="Didn't call Close on UserStreamListener" req.id=kQrtSRo4EDSm req.method=GET req.path=/_matrix/client/r0/sync

(Of course we don’t need millisecond precision but you get the idea)

But yeah, different log handlers. Telegram log handler could wrap some nice markdown around while stdout handler could look like that.

[yangm97]

Since the issue was too broad and "logging" has "improved", I'm going to close this.