---
title: "A working example | Grafana Labs"
description: "Tracking request latency without a per-user series explosion"
---

> For a curated documentation index, see [llms.txt](/llms.txt). For the complete documentation index, see [llms-full.txt](/llms-full.txt).

## A working example

Suppose you track request latency and want to find slow requests for specific users.

- **Instead of** `http_request_duration_seconds{user_id="u-48221", ...}`, which creates a series per user per label combination,
- **keep the metric as** `http_request_duration_seconds{service="checkout", env="prod"}`,
- **and log each request** with `user_id` and `request_id` attached as structured metadata.

When latency spikes, the metric tells you where and when. Then you query the logs for that service and window, filtering by structured metadata: `{app="checkout"} | user_id="u-48221"`. You keep full debugging detail without paying for it on every series.