Prometheus is an open-source monitoring system started in 2012 by former Google engineers. It uses a pull-based architecture to easily scale and features a powerful multi-dimensional data model and query language. Prometheus scrapes metrics from instrumented jobs like node exporters and stores time series data which can then be queried and graphed.

1. Prometheus
A next-genera1on monitoring system

2. History
• Started in 2012 by ex-Google Site Reliability
Engineers
• Wri?en in Go
• Inspired by Google’s Borgmon
– Borgmon monitors Borg
• Public announcement in January 2015
h?p://www.slideshare.net/FabianReinartz/prometheus-a-next-gen-monitoring-system-3

3. Features
• pull architecture
– easy to scall out
• mul1 dimensional data model
• powerful query language

4. pull architecture
h?ps://prometheus.io/docs/introduc1on/overview/

5. Demo
• node_exporter(machine metrics)
• prometheus server configura1on

6. mul1 dimensional data model
• metric types
– counter
– gauge
– histogram
– summary
h?ps://prometheus.io/docs/concepts/metric_types/

7. h?p://www.boxever.com/the-power-of-mul1-dimensional-labels-in-prometheus
Counter Java Code Example

8. Counter Metric Example
...
h?p_response_status_total{status="200”} @1460708848.148 277504
h?p_response_status_total{status=“200”} @1460708843.148 277503
h?p_response_status_total{status="200”} @1460708838.148 277502
h?p_response_status_total{status=“200”} @1460708833.148 277501
...
metric name label name 1mestamp sample value

9. How to handle counter metric
• Do you use reset?
• Do you use moving average?
h?p://www.robustpercep1on.io/how-does-a-prometheus-counter-work/
No! use rate/irate/increase func1on!
rate(h?p_response_status_total[1m])

10. powerful query language
sum by(status) (
rate(h?p_response_status_total [1m]))
)
ALERT DiskWillFillIn4Hours
IF predict_linear(node_filesystem_free{job='node'}[1h], 4*3600) < 0
FOR 5m
LABELS {
severity="page"
}
h?p://www.robustpercep1on.io/reduce-noise-from-disk-space-alerts/

11. Demo(access log)
• fluent-plugin-prometheus
• prometheus query
• grafana graph