From 8b62f06e929b56276eb90c95abde2f0c8e2d1734 Mon Sep 17 00:00:00 2001 From: Callum Styan Date: Wed, 31 Mar 2021 00:58:59 -0700 Subject: [PATCH] Quick documentation of the exemplars feature on the disabled features (#8655) page. Signed-off-by: Callum Styan --- docs/disabled_features.md | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/docs/disabled_features.md b/docs/disabled_features.md index 38753512ab..08a847f449 100644 --- a/docs/disabled_features.md +++ b/docs/disabled_features.md @@ -38,3 +38,11 @@ More details can be found [here](querying/basics.md#offset-modifier). The remote write receiver allows Prometheus to accept remote write requests from other Prometheus servers. More details can be found [here](storage.md#overview). +## Exemplars Storage + +`--enable-feature=exemplar-storage` + +[OpenMetrics](https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md#exemplars) introduces the ability for scrape targets to add exemplars to certain metrics. Exemplars are references to data outside of the MetricSet. A common use case are IDs of program traces. + +Exemplar storage is implemented as a fixed size circular buffer that stores exemplars in memory for all series. Enabling this feature will enable the storage of exemplars scraped by Prometheus. The flag `storage.exemplars.exemplars-limit` can be used to control the size of circular buffer by # of exemplars. An exemplar with just a `traceID=` uses roughly 100 bytes of memory via the in-memory exemplar storage. +