Data model

Every time series is uniquely identified by its metric name and optional key-value pairs called labels.

The metric name specifies the general feature of a system that is measured (e.g. - the total number of HTTP requests received). It may contain ASCII letters and digits, as well as underscores and colons. It must match the regex [a-zA-Z_:][a-zA-Z0-9_:]*.

Note: The colons are reserved for user defined recording rules. They should not be used by exporters or direct instrumentation.

Label names may contain ASCII letters, numbers, as well as underscores. They must match the regex [a-zA-Z_][a-zA-Z0-9_]*. Label names beginning with __ are reserved for internal use.

Label values may contain any Unicode characters.

A label with an empty label value is considered equivalent to a label that does not exist.

Samples form the actual time series data. Each sample consists of:

• a millisecond-precision timestamp

Given a metric name and a set of labels, time series are frequently identified using this notation:

For example, a time series with the metric name and the labels method="POST" and handler="/messages" could be written like this: