Files
neon/pageserver
Christian Schwarz aad410c8f1 improve ondemand-download latency observability (#11421)
## Problem

We don't have metrics to exactly quantify the end user impact of
on-demand downloads.

Perf tracing is underway (#11140) to supply us with high-resolution
*samples*.

But it will also be useful to have some aggregate per-timeline and
per-instance metrics that definitively contain all observations.

## Summary of changes

This PR consists of independent commits that should be reviewed
independently.

However, for convenience, we're going to merge them together.

- refactor(metrics): measure_remote_op can use async traits
- impr(pageserver metrics): task_kind dimension for
remote_timeline_client latency histo
  - implements https://github.com/neondatabase/cloud/issues/26800
- refs
https://github.com/neondatabase/cloud/issues/26193#issuecomment-2769705793
- use the opportunity to rename the metric and add a _global suffix;
checked grafana export, it's only used in two personal dashboards, one
of them mine, the other by Heikki
- log on-demand download latency for expensive-to-query but precise
ground truth
- metric for wall clock time spent waiting for on-demand downloads

## Refs

- refs https://github.com/neondatabase/cloud/issues/26800
- a bunch of minor investigations / incidents into latency outliers
2025-04-04 18:04:39 +00:00
..