The info function is an experiment to improve UX around including labels from info metrics . The behavior of this function may change in future versions of Prometheus, including its removal from PromQL.

July 9, 2026 - PromQL functions perform calculations with and on your metrics data, letting you complete complex processing with pre-built operations. Each function takes different arguments, but typically at minimum, an instant or range vector.

October 7, 2024 - PromQL comes with a variety of built-in functions to help users analyze metrics. Functions in PromQL allow transformations, aggregations, and mathematical operations on time-series data.

type FunctionCall func(vectorVals []Vector, matrixVals Matrix, args parser.Expressions, enh *EvalNodeHelper) (Vector, annotations.Annotations)

September 12, 2024 - PromQL cheat sheet: quick diagnostic queries, aggregation functions, label filtering, SLO tracking, capacity planning, and multi-cluster patterns for Prometheus monitoring.

Functions that convert between scalars and instant vectors. ... Returns the sample value of a single-element instant vector as a scalar. If the input vector does not have exactly one element, scalar returns NaN.

October 9, 2024 - PromQL is defined in great detail ... http_requests_total{status="200"}. Functions, such as abs to take the absolute value or rate to compute the rate of increase per second....

February 26, 2025 - The most important functions are those that manipulate and analyze time series data, including rate calculations, deltas, and histogram analysis which we'll explore in some upcoming sections.

November 29, 2024 - PromQL includes a wide range of functions that simplify tasks like rate calculation, data aggregation, and histogram analysis.

April 25, 2025 - This function looks at all data points collected over the past 3 minutes and returns the highest value to represent those samples. ... In the example above, max_over_time is evaluated at every 5-minute step between 00:10 and 00:30. Each time, it looks back over the previous 3 minutes, collects the samples, and returns the maximum value found in that range. PromQL and MetricsQL both support many rollup functions.

Both float samples and histogram ... writing PromQL queries. (By convention, time series containing float counters have a name ending on _total to help with the distinction.) Since histogram samples “know” their counter or gauge flavor, this allows reliable warnings about mismatched operations. For example, applying the rate function to gauge floats ...

August 19, 2025 - PromQL common functions · Billing · Billing overview · Billing methods · Pay-as-you-go · Package · Package Overview · Purchasing packages · Viewing Packages · Renew Package · Canceling packages and changing package specifications · Price calculator ·

September 15, 2023 - VictoriaMetrics extends these functions with more convenient label manipulation functions: label_set — sets additional labels to time series · label_del — deletes the given labels from time series · label_keep — deletes all the labels from time series except the given labels · label_copy — copies label values to another labels ... Sometimes it is necessary to return multiple results from a single PromQL query.

February 28, 2025 - The resets() function helps you identify when this happens: ... This returns the number of counter resets within the last hour, which can be a useful indicator of service stability. To detect sudden changes in rates, you can compare the short-term rate to a longer-term average: ... This alerts when the 5-minute rate differs from the 1-hour rate by more than 30%, indicating a significant change in traffic patterns. PromQL supports powerful label matching techniques that let you zero in on exactly the metrics you care about:

All other operations result in the removal of the corresponding element from the output vector, flagged by an info-level annotation. The + and - operations should generally only be applied to gauge histograms, but PromQL allows them for counter histograms, too, to cover specific use cases, for which special attention is required to avoid problems with unaligned counter resets.

March 12, 2026 - PromQL uses two types of arguments - range and instant vectors. Range vectors have a time dimension, while instant vectors represent the most recent data point. rate() and similar functions require range arguments for trend analysis.

March 12, 2026 - You're not shoehorning traditional data models into a time-series context. Powerful Aggregations and Functions: PromQL offers a rich set of functions for summing, averaging, counting, calculating rates, and much more.

September 2, 2023 - Prometheus supports a large number of functions, aggregation operators, and binary operators. Other features include hashed comments by line (like many other languages) and subqueries for instantaneous queries when triggered. Subqueries, a themselves a feature of PromQL’s nested expression capabilities, allow for some sophisticated querying.

Use irate for fast-changing counters or when you need to see rapid changes. Use increase when you want the absolute increase rather than a per-second rate. PromQL offers various mathematical functions to transform your data.