What best practices are recommended for naming metrics and tags?

What best practices are recommended for naming metrics and tags?

Datadog recommends certain best practices for naming metrics, tags, and services.

Rules and best practices for naming metrics

  • Metric names must start with a letter.
  • Can only contain ASCII alphanumerics, underscores, and periods. Other characters are converted to underscores.
  • Should not exceed 200 characters (though less than 100 is generally preferred from a UI perspective)
  • Unicode is not supported.
  • It is recommended to avoid spaces.

Metrics reported by the Agent are in a pseudo-hierarchical dotted format, for example: http.nginx.response_time. This is described as pseudo-hierarchical because a hierarchy is not actually enforced, but the structure is used to infer certain relationships, for example: “I see hostA and hostB are reporting http.nginx.*, those must be web frontends”).

Note: Metric names are case sensitive in Datadog.

Rules and best practices for naming tags

As a best practice, Datadog recommends using unified service tagging when assigning tags. Unified service tagging ties Datadog telemetry together through the use of three standard tags: env, service, and version. To learn how to configure your environment with unified tagging, see Unified service tagging.

  • Tags must start with a letter.
  • May contain alphanumerics, underscores, minuses, colons, periods, and slashes. Other characters are converted to underscores.
  • A trailing underscore is removed, whether if it originated from a converted character or if it was in the original tag value.
  • Contiguous underscores are reduced to a single underscore.
  • Tags can be up to 200 characters long and support Unicode.
  • Tags are converted to lowercase.
  • For optimal functionality, it is recommended to use the key:value syntax.

Examples of commonly used metric tag keys are instance, name, and role.

Further Reading