[alkonaut]

I like a log to read like a book if it’s the result of a task taking a finite time, such as for example an installation, a compilation, a loading of a browser page or similar. Users are going to look into it for clues about what happened and they a) aren’t always related to those who wrote the tools b) don’t have access to the source code or any special log analytics/querying tools.

That’s when you want a log and that’s what the big traditional log frameworks were designed to handle.

A web backend/service is basically the opposite. End users don’t have access to the log, those who analyze it can cross reference with system internals like source code or db state and the log is basically infinite. In that situation a structured log and querying obviously wins.

It’s honestly not even clear that these systems are that closely related.

[WatchDog]

It’s a good distinction to make, logging for client based systems, is essentially UI design.

For a web app, serving lots of concurrent users, they are essentially unreadable without tools, so you may as well optimise the logs for tool based consumption.