FWIW, Prometheus was significantly infuenced by Borgmon; more details, some fun.

AIUI, Prometheus was implemented by a bunch of folks at SoundCloud, some of whom were ex-Google SREs (hi, BR!). Borgmon had some weaknesses (for example, multiple separate templating implementations, for historical reasons) which as far as I know, Prometheus doesn’t share. Today, Prometheus advocates include a number of ex-Google SREs. For example Brian Brazil (see book) who if I recall correctly implemented a Turing Machine emulator in Borgmon.

Today, Borgmon has been largely replaced in Google by Monarch, which addresses quite a few of the pain points of operating Borgmon infrastructure, and even manages to remove some of the complexity. Though less than I thought it would, which leaves me wondering how much of the complexity is simply unavoidable because it’s inherent in the problem space.

1. There are some inherent complexities in the space.
2. Lack of network effects around a (missing) standard implementation or protocol.

I think this could have been different. Nagios had a first-comer advantage for Linux, but it mostly stayed centred on network monitoring, while application monitoring is the key thing.

I say application monitoring is the key thing mainly because what we actually want to know is, is the system as a whole functioning correctly? Without positive evidence that the application is succeeding we can’t tell for sure.