---
title: "Triage and Fix with Confidence: heroku run and OTel on Heroku Fir"
description: "Heroku Fir addresses production troubleshooting when a release causes failures, such as a background worker breaking after a database schema change, without requiring access to a live formation dyno. Its interactive heroku run command launches a dedicated one-off dyno with the application code and environment variables, relaying terminal input and output for tasks such as rake db:migrate; using it requires a public SSH key and a deployed application. The platform’s native OpenTelemetry (OTel) signals add router request-duration summaries and percentiles, represent heroku.router.connect and heroku.router.service as floats, and attach heroku.app.name to application signals. Together with service.name filtering for first-party services, these capabilities support identifying affected applications, applying isolated fixes, and verifying latency and errors through an observability platform."
---

# Triage and Fix with Confidence: heroku run and OTel on Heroku Fir

[Heroku](https://yomu.fyi/company/heroku) · Su Glasgo · Sep 8, 2025

**Type:** Explainer

## Summary

Heroku Fir addresses production troubleshooting when a release causes failures, such as a background worker breaking after a database schema change, without requiring access to a live formation dyno. Its interactive heroku run command launches a dedicated one-off dyno with the application code and environment variables, relaying terminal input and output for tasks such as rake db:migrate; using it requires a public SSH key and a deployed application. The platform’s native OpenTelemetry (OTel) signals add router request-duration summaries and percentiles, represent heroku.router.connect and heroku.router.service as floats, and attach heroku.app.name to application signals. Together with service.name filtering for first-party services, these capabilities support identifying affected applications, applying isolated fixes, and verifying latency and errors through an observability platform.

## Context

Production incidents can follow a release that includes a database schema change, causing dependent background worker tasks to fail while the web application remains available. Troubleshooting directly on a running web dyno can consume resources and risk destabilizing the live service, while detached commands do not provide an interactive diagnostic session.

## Approach / What changed

Use heroku run on Heroku Fir to launch an interactive, dedicated one-off dyno for administrative or maintenance commands, such as rake db:migrate. Fir also supplies native OpenTelemetry signals with standardized attributes, request-duration percentiles, heroku.app.name on application signals, and service.name filtering for first-party services.

## Takeaways

- heroku run provides an interactive session on a dedicated one-off dyno, separate from formation dynos; Fir requires a public SSH key and a deployed application.
- Heroku router telemetry includes request-duration summary statistics and percentiles, including http.server.request.duration.p0-999 for the 99th percentile.
- The heroku.app.name attribute is added to application logs, metrics, and traces, while service.name enables filtering signals from services such as Heroku Postgres and Heroku Kafka.

**Tags:** [Heroku](https://yomu.fyi/topic/heroku), [Observability](https://yomu.fyi/topic/observability), [OpenTelemetry](https://yomu.fyi/topic/opentelemetry)

- Source: [Heroku](https://www.heroku.com/blog/heroku-run-and-otel-on-heroku-fir)
- Source URL: https://www.heroku.com/blog/heroku-run-and-otel-on-heroku-fir
- Ingested by Yomu: 2026-09-10T04:04:47.786Z

[Read original post](https://www.heroku.com/blog/heroku-run-and-otel-on-heroku-fir)