---
title: "Grafana"
description: "3 posts about Grafana, summarised, each linking to the original."
---

# Grafana
> 3 posts about Grafana, summarised, each linking to the original.

## Articles

### [OpenTelemetry Basics on Heroku Fir](https://yomu.fyi/post/opentelemetry-basics-on-heroku-fir.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Alex Arnell
- Published: May 27, 2025
- Type: Tutorial

Heroku Fir includes OpenTelemetry as a built-in observability capability, addressing the need to monitor increasingly distributed and complex applications. The post introduces OpenTelemetry’s logs, metrics, and traces, while noting that events and profiles are under development. It distinguishes application-embedded SDKs, which generate and process telemetry, from standalone collectors that receive, process, and export data, although Fir acts as the central hub for telemetry pipelines. The walkthrough uses the Go getting-started app in a Fir space, creates Grafana Cloud credentials and environment variables, converts OTLP headers to JSON, and adds an HTTP Heroku Telemetry Drain with the CLI. After deployment and browser refreshes, application metrics appear in Grafana Cloud, followed by traces and logs.


### [Monitoring Elixir Apps on Fly.io With Prometheus and PromEx](https://yomu.fyi/post/monitoring-elixir-apps-on-fly-io-with-prometheus-and-promex.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: Jun 28, 2021
- Type: Tutorial

Monitoring Elixir applications on Fly.io, the post presents a way to add production visibility without administering a Prometheus instance. Fly.io’s managed service scrapes an application’s metrics endpoint at a configured interval, with fly.toml specifying the port and path; Prometheus stores the resulting time-series snapshots and Grafana queries them with PromQL. PromEx supplies Elixir instrumentation through plugins for components such as the application, BEAM, Phoenix, Ecto, and Phoenix LiveView, while optionally uploading dashboards and annotating application lifecycle events through Grafana’s HTTP API. The example enables Fly.io metrics on port 4000 at /metrics and configures PromEx dashboards for a Todo List application. The stated result is an instrumented application with dashboards and annotations in minutes, while monitoring can also support rollback decisions, stress-test analysis, prioritization, and capacity planning.


### [Hooking Up Fly Metrics](https://yomu.fyi/post/hooking-up-fly-metrics.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: May 20, 2021
- Type: Tutorial

Fly apps include built-in Prometheus instrumentation, exposing automatically collected metrics through a public Prometheus endpoint and allowing applications to export custom metrics. The walkthrough connects an organization’s Fly Prometheus URL to Grafana with a Fly token, then explains dashboard variables and PromQL queries using counters, gauges, histograms, labels, irate(), rate(), increase(), sum(), and regional grouping. Examples cover network traffic, TCP connections, HTTP response rates by region, and response-time heatmaps built from histogram buckets ranging from 5ms to 120s. Application instrumentation is shown for Go, Python Flask, and Node.js, with scraping configured in fly.toml through a metrics port and path. The post concludes that metrics are currently free, with some tier free forever, although a future pricing plan is expected for ambitious usage.