Introduction to Prometheus, PromQL, & PromLens

In this episode, I am joined by Julius Volz; co-founder of Prometheus, and founder of PromCon and PromLabs.

Prometheus is an open-source systems monitoring and alerting toolkit originally built at SoundCloud. Since its inception in 2012, many companies and organisations have adopted Prometheus, and the project has a very active developer and user community. It is now a standalone open source project and maintained independently of any company. To emphasise this, and to clarify the project's governance structure, Prometheus joined the Cloud Native Computing Foundation in 2016 as the second hosted project, after Kubernetes.


PromQL, the query language of the Prometheus monitoring system, is great for doing calculations on time series data. However, the language also has plenty of sharp edges and can be challenging to learn and work with for both beginners and more advanced users. Whether it's knowing the language itself, reading complicated queries, or understanding the shape of the data you have to work with, there is often a lot of pain and guesswork involved. In the worst case, you might not notice that your service is down because an alerting expression is incorrect.

PromLens is a tool by PromLabs that makes learning and using PromQL easier and more productive. It integrates a visual query builder with explanation and visualization features. It also allows you to share queries with colleagues or friends.



🕰 Timeline

00:00 - Holding screen
01:30 - Introductions
02:30 - What is Prometheus?
08:00 - Why write your own database?
15:00 - Running Prometheus
18:00 - Prometheus configuration
21:00 - Exploring and understanding Prometheus metrics
38:00 - Querying with the Prometheus UI
40:00 - Adding the node_exporter
45:00 - A new UI: PromLens
48:10 - Using the rate function
50:20 - Why PromLens and a look at its editor and features
1:00:15 - Contrived situation - lets fill up the disk
1:24:00 - Final thoughts
1:25:00 - Viewer question: What metrics are important for a web application?


💁🏻‍♂️ Want some help?

💬 Leave a comment
🐦 Ping me on Twitter - https://twitter.com/rawkode
📆 Schedule some time during my office-hours - https://rawko.de/office-hours


🌎 Links

Julius Volz - https://twitter.com/juliusvolz
Prometheus - https://prometheus.io
PromLens - https://promlens.com