An Introduction to Prometheus for App Developers

I've presented this talk at KubeCon 2017 in Austin.

The video recording of this available on YouTube: https://youtu.be/-7fO99IiTpY.

Transcript

1. @errordeveloper An Introduction to Prometheus for App Developers
2. I build apps, and I do microservices
3. I let k8s run my apps for me
5. observability is absolutely essential
6. end goal: continuous improvement
11. why must I instrument my app!?
12. microservices is a culture
13. what is Prometheus & why use it?
14. what is Prometheus & why use it?
15. how do I instrument my app for Prometheus?
16. /metrics
17. /metrics Content-Type: text/plain
18. <name:string> <value:float>
19. new_users_count 250.0
20. <name:string>{<labels>} <value:float>
21. new_users_count{locale=“en_GB”} 49.0 new_users_count{locale=“pt_BR”} 51.0 new_users_count{locale=“ru_RU”} 45.0 new_users_count{locale=“zh_HK”} 55.0 new_users_count{locale=“zh_TW”} 50.0
22. > curl -i http://myapp:8080/metrics Content-Type: text/plain ... process_uptime_seconds 145236.015 http_requests_duration_seconds_count 2.0 new_users_count 250.0
23. > curl -i http://myapp:8080/metrics Content-Type: text/plain ... http_requests_count{method="GET",status="200",uri="/"} 1.0 http_requests_count{method=“PUT”,status=“403",uri="/"} 1.0
24. prometheus.io/docs/concepts/metric_types
25. how do I use it to improve my app?
26. process_uptime_seconds
27. process_uptime_seconds{job=“myapp”}
28. http_requests_duration_seconds_count
29. http_requests_duration_seconds_count{ job=“myapp”, method=“GET”, uri=“/”, }
30. sum( http_requests_duration_seconds_count{ job=“myapp”, method=“GET”, uri=“/”, } )
31. sum( rate( http_requests_duration_seconds_count{ job=“myapp”, method=“GET”, uri=“/”, }[1m] ) )
32. up
33. up{job=“myapp"}
34. sum( up{job=“myapp"} ) by (job)
35. tutorial: step-by-step guide to Prometheus with Node.js http://github.com/errordeveloper/prom-nodejs-demo
36. cloud.weave.works
37. ilya@weave.works slack.weave.works