selector

Selectors allow selecting and filtering of a set of time series.

Simple Selector

In the simplest form you need to specify only a metric name.

Syntax

<line> ::= <metric_name_pattern>
<metric_name_pattern> ::= simple pattern

The metric name pattern syntax is simple pattern.

Examples

This example selects all time series that have the go_memstats_alloc_bytes metric name:

go_memstats_alloc_bytes

This example selects all time series with metric names starts with go_memstats_:

go_memstats_*

This example selects all time series with metric names starts with go_ except go_memstats_:

!go_memstats_* go_*

Advanced Selector

It is possible to filter these time series further by appending a comma separated list of label matchers in curly braces ({}).

Syntax

<line> ::= [ <metric_name_pattern> ]{ <list_of_selectors> }
<metric_name_pattern> ::= simple pattern
<list_of_selectors> ::= a comma separated list <label_name><op><label_value_pattern>
<label_name> ::= an exact label name
<op> ::= [ '=', '!=', '=~', '!~', '=*', '!*' ]
<label_value_pattern> ::= a label value pattern, depends on <op>

The metric name pattern syntax is simple pattern.

Label matching operators:

  • =: Match labels that are exactly equal to the provided string.
  • !=: Match labels that are not equal to the provided string.
  • =~: Match labels that regex-match the provided string.
  • !~: Match labels that do not regex-match the provided string.
  • =*: Match labels that simple-pattern-match the provided string.
  • !*: Match labels that do not simple-pattern-match the provided string.

Examples

This example selects all time series that:

  • have the node_cooling_device_cur_state metric name and
  • label type value not equal to Fan:
node_cooling_device_cur_state{type!="Fan"}

This example selects all time series that:

  • have the node_filesystem_size_bytes metric name and
  • label device value is either /dev/nvme0n1p1 or /dev/nvme0n1p2 and
  • label fstype is equal to ext4
node_filesystem_size_bytes{device=~"/dev/nvme0n1p1$|/dev/nvme0n1p2$",fstype="ext4"}

Label matchers can also be applied to metric names by matching against the internal __name__ label.

For example, the expression node_filesystem_size_bytes is equivalent to {__name__="node_filesystem_size_bytes"}. This allows using all operators (other than =*) for metric names matching.

The following expression selects all metrics that have a name starting with node_:

{__name__=*"node_*"}
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