Prometheus promql

PromQL is prometheus's query language.
It's syntax is inspired by golang.
You can query prometheus from

• HTTP API
• in the UI's graph?

Documentation

official docs	https://prometheus.io/docs/prometheus/latest/querying/basics/
official examples	https://prometheus.io/docs/prometheus/latest/querying/examples/
re2 (regex engine)	https://github.com/google/re2/wiki/Syntax

Comments

# a comment

Datatypes

Strings

// string
"foo"
`foo`

// string-literal
'foo\nbar'

Floats

23
-2.43
3.4e-9
0x8f
-Inf
NaN

Queries

Metric-Selector

The most basic query you can use is your_metric_name which queries all samples for that metric.
These metric selectors can be composed and filtered.

{__name__="your_metric_name"}            // query all (you can match multiple metrics this way)

your_metric_name                         // query all
your_metric_name[5min]                   // lump data into 5min clumps
your_metric_name{job="foo",group="bar"}  // filter by metric-labels

Operators

label metrics support various matchers/operators

=   // equal
!=  // not-equal
=~  // regex match
!~  // not regex match

Clustering Metrics

TODO:

are these aggregates averages? sums? greatest-value?

your_metric_name[5min]   // lump data into 5min clumps

Units

ms  // milliseconds
s   // seconds
m   // minutes
h   // hours
d   // days
w   // weeks
y   // years

Query Time Ranges

your_metric_name offset 5min   // query 5min-ago until present

your_metric_name @ 1609746000  // query at exactly '2021-01-04T07:40:00+00:00'