It is no secret that I am not a fan of logs; I’ve baited (rapala in work lingo. Rapala is a Finnish brand of fishing lure, and used to mean baiting in this context) discussion in our work chat with things like: If you’re writing log statements, you’re doing it wrong. This is a pretty incendiary statement, and while there has been some good discussion after, I figured it was time to write down why I think logs are bad, why tracing should be used instead, and how we get from one to the other.

TLDR; The author argues that free-form logging is quite useless/expensive to use. They also argue that structured logging is less effective than tracing b/c of mainly the difficulty of inferring timelines and causality.

I find the arguments very plausible.

In fact I very rarely use logs produced by several services b/c most of the times they just confuse me. The only time that I heavily use logs is troubleshooting a single service and looking at its stdout (or kubectl log.)

However I have very little experience w/ tracing (I’ve used it in my hobby projects but, obviously, they never represent the reality of complex distributed systems.)

Have you got real world experience w/ tracing in larger systems? Care to share your take on the topic?