Metric and label naming conventions

The Prometheus naming conventions are a style guide and collection of best practices, not a requirement. A metric name MUST comply with the data model for valid characters, SHOULD carry a single-word application prefix (called a namespace by client libraries, as in prometheus_notifications_total or process_cpu_seconds_total), MUST refer to a single unit and a single quantity, SHOULD use base units (seconds, bytes, meters — not milliseconds or megabytes), and SHOULD end with the unit in plural form, with total as the suffix for accumulating counts and _info for pseudo-metrics exposing metadata. Common name components MAY be ordered first so related metrics sort together. Each metric SHOULD represent the same logical thing-being-measured across all label dimensions — sum() or avg() over a metric's dimensions should be meaningful. Use labels to differentiate characteristics (operation="create|update|delete") and never put label names in the metric name. Every unique label combination is a new time series, so avoid high-cardinality values like user IDs or email addresses. Scope: Prometheus. Reviewed October 4, 2026.