Chapter 2 of 6 · 4 practices · 3 min · 4-question quiz
Metrics that stay useful and affordable
How to name, type and label metrics so queries are obvious and the time series count does not explode.
Start: Name metrics with base units and standard suffixes4 practices in this chapter
- 1Name metrics with base units and standard suffixesA metric called
request_timeleaves everyone guessing: milliseconds or seconds, a total or a histogram? The Prometheus naming guide removes the guesswork: Use base units: seconds, bytes, meters… - 2Use counters for things that only go up, gauges for everything elseThe Prometheus instrumentation guide's rule is simple: if the value can go down, it is a gauge. Counters only increase, and reset to zero when the process restarts.
- 3Keep label cardinality low, and never label by user or requestEvery unique combination of label values is a separate time series, with its own storage and memory. One unbounded label can multiply your bill or take down the metrics backend.
- 4Instrument each kind of service for what it doesThe Prometheus instrumentation guide splits services into three kinds, each with its own key metrics: For offline pipelines, the guide suggests a heartbeat: a dummy item sent through the pipeline…
Check yourself on this chapter
4 questions, right here once you are signed in. Your progress is saved as you read.