USE-METHOD

Three resource metrics: U, S, E.

Definition

USE applies to resources: CPU, Memory, Disk I/O, Network. Utilization = % busy time. Saturation = queue depth (run queue, I/O queue). Errors = hardware/driver errors. Complementary to RED (services).

Origin

Published by Brendan Gregg in 2013 on brendangregg.com ; book Systems Performance 2nd ed. 2020.

Example in context

An EDI server tracks USE for CPU: utilization > 80% sustained + saturation > 1 → capacity alert.

Related terms

• RED — service complement.