PromQL
Prometheus's functional query language for selecting and aggregating time-series metrics.
Definition
PromQL (Prometheus Query Language) is a functional query language that lets users select and aggregate time series data in real time. It is specifically designed for querying metrics in Prometheus, one of the most widely used open-source monitoring systems.
In depth
PromQL expressions range from simple metric selectors (`http_requests_total`) to complex multi-step aggregations with rate calculations, label filtering, and binary operations between different time series. Its functional approach — where operations compose together — makes it expressive for computing rates, ratios, percentiles, and topk/bottomk rankings. PromQL has become so influential that many commercial monitoring systems implement PromQL-compatible query layers. obseria.io supports PromQL natively for querying Prometheus-compatible metrics, meaning existing dashboards and alert rules migrate without modification.
Related terms
See PromQL in action
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