FWIW, I have no CS degree and barely attended school at all, and found Grafana + Prometheus + Loki fairly easy to setup, at least compared to what we used to use before those tools were available. Maybe it's because I used NixOS for the setup, but besides learning some new domain-specific things I didn't know since before, I don't recall hitting any particular bumps or roadblocks, I also went the 100% self-hosted route (spread across two hosts at home).
What exactly were you struggling with when it came to the setup? Just a ton of new concepts to learn which took time, or something specific to Grafana/Prometheus/Loki?
"Getting it running" is the easy part.
"Getting it ready for production" is a different game.
I've fallen on my sword many times by trying to explain that prometheus fails every metric of production ready; in fact Google themselves replaced borgmon (prometheus) for Monarch because the "tiny unreliable time series databases everywhere" was in fact, not the successful and reliable deployment strategy that they had claimed.
But, it is very easy to set up. Just don't go looking for failure modes, because they're everywhere and every single one of them is catastrophic.
There are ways to scale Prometheus (look at Thanos), but none of the solutions is really bug free.
See this PR for example (https://github.com/prometheus/prometheus/pull/18364) - this used to impact a production deployment I worked on. Prometheus, Thanos and even OpenTelemetry are full of those kind of problems - but at the same time it's the best we have and we should be grateful they're free and open source.
I'd still choose an open source stack (and contribute to it) rather than go for a proprietary solution - we've all seen what happens with DataDog & co.
Please don't take my words lightly, I worked with the rest of my team in a large scale observability platform and scalability should not be underestimated - at the same time DataDog / Splunk prices are simply unjustified. It's ironically cheaper to build a team of engineers that will maintain a sane observability stack instead of feeding the monster(s).
Well, I am running the stack in production right now, but everyone has a different understanding of what that actually means...
Do you have concrete examples of these catastrophic failures? I've personally havent experienced any myself during these years, but I'm doing very boring and typical stuff, so wouldn't surprise me there was hard edges still.
There's a difficult distinction here, you're right.
Technically even a single server running LAMP as root but taking frontend traffic meets the definition of in production but I think we all recognise that it's not the right idea.
What I'm referring to is: should the disk start to have issues: what does prometheus do? If the scrapers start to stall due to connection timeouts: what does prometheus do? If you are doing linear interpolation of data and you have massive gaps because you're polling opportunisitically: what does prometheus do.
I'm all about boring technology, but prometheus assumes too much happy path. It assumes that a single node is enough for time series data that is used for alerting.
Which, it is: at very small scale and with best effort reliability.
It's not acceptable as soon as lost data could be critically important in diagnosing major issues in billing systems, or actually billing users, or to infer issues that need to be correlated across multiple systems.