Hands-On Infrastructure Monitoring with Prometheus

Arithmetic

The arithmetic operators provide basic math between two operands.

There are three available combinations of operands. The simplest is between two scalars, which will return a scalar after applying the chosen arithmetic operator. We can also combine an instant vector and a scalar, which will apply the chosen arithmetic operator between the scalar and each sample of the instant vector, effectively returning the same instant vector with updated samples. The last combination we can have is between two instant vectors. In this case, the arithmetic operator is applied between the vector from the left-hand side and the matching element from the right-hand side vector, while the metric name is dropped. If no match is present, those samples ...