---
title: "Heroku"
description: "62 posts about Heroku, summarised, each linking to the original."
---

# Heroku
> 62 posts about Heroku, summarised, each linking to the original.

## Articles

### [Building a Monorepo with Yarn 2](https://yomu.fyi/post/building-a-monorepo-with-yarn-2.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Danielle Adams
- Published: Dec 23, 2020
- Type: Tutorial

The post presents Yarn 2 workspaces as a way to manage dependencies for a JavaScript or Node.js monorepo containing separate server and UI applications. It configures the root package.json with workspace directories, imports the workspace-tools plugin, pins the project to a checked-in Yarn binary with yarn set version berry, and enables the dependency cache through .yarn/cache and Plug’n’Play. The walkthrough adds Express, TypeScript, and @types/express to a server workspace, creates a Next.js UI workspace, and uses workspace scripts to build both applications, while yarn dlx initializes TypeScript without a global install. It also shows the Git files to retain, generated JavaScript to ignore, and a Heroku start script that launches the server workspace; the stated benefit is faster installs through a committed cache and zero-install deployment.


### [Extend Flows with Heroku Compute: An Event-Driven Pattern](https://yomu.fyi/post/extend-flows-with-heroku-compute-an-event-driven-pattern.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Chris Marino
- Published: Dec 11, 2020
- Type: Tutorial

The post presents an event-driven pattern for extending Salesforce Flow with custom business logic deployed as a Heroku app and exposed as an external service. It uses an OpenAPI specification to define the interface, generates a Node.js application stub, adapts it for Heroku with a Procfile and port configuration, and registers the API in Salesforce. Flow accesses the service through a Named Credential using basic HTTP authentication, while the Heroku app authorizes Salesforce access with a JWT account token and API token. The example begins with product retrieval and then adds a Get Inventory method that can read inventory and update the Salesforce Product object. A Platform Event can trigger a flow that calls this method, while programmers and low-code builders iterate against the shared API contract before completing their work independently.


### [How I Broke \`git push heroku main\`](https://yomu.fyi/post/how-i-broke-git-push-heroku-main.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Damien Mathieu
- Published: Oct 1, 2020
- Type: Incident / postmortem

Incident #2105 began during a production deployment of a Go-based Git server after a configuration variable had been set but not transmitted to production instances. Staging deployment completed successfully before the same change was attempted in production. The deployment sent a new code version to one batch, whose unauthenticated calls to a private API produced HTTP 401 responses that were returned publicly; the author paused before deploying the remaining batches and resolved the issue by synchronizing configuration, killing affected processes, and allowing them to restart. The post argues that the failure was enabled by a process requiring separate, infrequent manual actions rather than being solely an individual omission. Its proposed remedy is to combine configuration synchronization with code deployment, or alternatively warn when deployment begins with unsynchronized variables, supported by a blameless retrospective.


### [Using Heroku Postgres From A Fly App](https://yomu.fyi/post/using-heroku-postgres-from-a-fly-app.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: Sep 28, 2020
- Type: Tutorial

A Fly application can use Heroku Postgres without migrating the application itself, with Heroku hosting an add-on-only app that provides the database. The setup provisions a Hobby Dev Heroku Postgres database, retrieves its URI credentials, and passes DATABASE\_URL to the Fly deployment as a secret. A Node REST API using Sequelize parses that URI with pg-connection-string, then supplies the database, user, password, and host while enabling SSL and setting rejectUnauthorized to false for Heroku’s certificate-chain issue. After fly deploy, the app connects externally to Postgres, but the Hobby plan limits it to 20 connections unless upgraded. The article presents Heroku’s US and Europe data-center choices as a way to keep the database relatively close while Fly places the application near users, and warns that credentials rotate periodically without notification.


### [Migrating Heroku Database Apps To Fly](https://yomu.fyi/post/migrating-heroku-database-apps-to-fly.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: Sep 25, 2020
- Type: Tutorial

Migrating a Heroku application to Fly requires attention to database connectivity because Heroku Postgres must be accessed over SSL from outside Heroku. The post uses the DATABASE\_URL environment variable, parses it with pg-connection-string, and passes a configured connector to Massive.js, setting sslmode to require and rejectUnauthorized to false to accommodate self-signed certificates in Heroku Postgres’s certificate chain. It also shows a local-development fallback that uses a non-SSL localhost Postgres connection when DATABASE\_URL is undefined. With these changes, Turboku can migrate the app and convert DATABASE\_URL into a Fly secret, while the application retains its database connection and can use Fly’s region and scaling controls. Database latency still depends on proximity to Heroku’s US or European database regions, so caching within Fly regions may matter for mission-critical performance.


### [From Project to Productionized with Python](https://yomu.fyi/post/from-project-to-productionized-with-python.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Ed Morley
- Published: Jun 22, 2020
- Type: Tutorial

The post presents a hands-on tutorial for Python developers moving a local Django application into production on Heroku. It frames the work around 12-factor practices and covers repository hygiene, modular settings, continuous delivery stages, static-asset middleware, environment configuration, database provisioning, deployment, scaling, and troubleshooting. The configuration changes include excluding virtual environments, caches, SQLite data, and generated static files; moving settings.py to settings/base.py; updating DJANGO\_SETTINGS\_MODULE; adding Whitenoise; and supplying SECRET\_KEY and a Heroku Postgres add-on. The deployment uses Git, the Heroku CLI, git push heroku main, and heroku ps:scale web=1, with heroku logs --tail and heroku run bash for diagnosis. The walkthrough concludes with the app deployed and accessible through heroku open.


### [Building and Scaling a Global Chatbot using Heroku + Terraform](https://yomu.fyi/post/building-and-scaling-a-global-chatbot-using-heroku-terraform.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Garen Torikian
- Published: Apr 22, 2020
- Type: Problem & solution

Live Agent, Salesforce’s embeddable chatbot, must handle customer interactions and requests at global scale while remaining highly available across regions. Its eight-person team chose Heroku to avoid managing bare metal, cloud virtual machines, databases, and other third-party services, while relying on managed Java support and regional infrastructure. The platform runs ten apps with Heroku Postgres, Redis, and Apache Kafka dependencies, and deploys them inside Heroku Private Spaces to isolate network boundaries and data. Terraform defines and replicates apps, add-ons, custom domains, logging, and profiling configuration across regions, allowing changes to propagate through a pull request. The result described is a simpler operational model in which Heroku handles maintenance and the team can scale the same architecture into new geographic locations.


### [Turboku - The Art Of Faster Heroku Apps](https://yomu.fyi/post/turboku-the-art-of-faster-heroku-apps.md)
- Company: [Fly.io](https://yomu.fyi/company/fly-io.md)
- Published: Feb 5, 2020
- Type: Benchmark

Turboku is a migration path that automatically turns Heroku web dynos into Fly applications, addressing how existing Heroku apps can move to Fly’s globally distributed edge network. Fly routes requests to the closest datacenter through one global IP address, or two with IPv6, while TLS terminates closer to users and modern ECDSA certificates are automatic for Fly domains. A benchmark around the world used an existing application to compare Heroku and Fly connection stages, full requests, and cached requests. Fly reduced DNS, TCP, TLS, network, and full-request times, with the largest reported improvement appearing when caching was used: 180.16 ms versus Heroku’s 817.75 ms, a 77.91% reduction; uncached full requests fell 35.39%, while TTFB was 1.24% higher.


### [Automated Continuous Deployment at Heroku](https://yomu.fyi/post/automated-continuous-deployment-at-heroku.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Bernerd Schaefer
- Published: Oct 22, 2019
- Type: Problem & solution

Heroku’s Runtime team replaced a manual, coordination-heavy deployment process after team growth and Common Runtime sharding expanded work from one infrequently changed application in two environments to multiple services across 12 environments. Existing Heroku Pipelines deploy merged, CI-passing changes to staging, while the Go-based cedar-service-deployer reconciles differences between pipeline stages and promotes them when a series of safety checks pass. Those checks include a 30-minute age gate, deployment and incident controls, master-branch verification, Librato alerts, and HTTP 200 checks for configured URLs, including platform integration tests. The stateless system can handle concurrent rollouts, and the team added practices such as isolated early stages, feature flags, and separated database-migration changes. After about two years, it managed 23 services, allowing engineers to merge and rely on healthy systems for global release.


### [Up to 75% Faster Maintenances with Heroku Postgres and Redis Premium Plans](https://yomu.fyi/post/up-to-75-faster-maintenances-with-heroku-postgres-and-redis-premium-pl.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Corey Purcell
- Published: Aug 28, 2019
- Type: Explainer

Heroku describes how it minimizes downtime during routine security and patching maintenances for high-availability Heroku Postgres and Heroku Redis plans. These plans run a writable primary alongside a hidden read-only standby, and maintenance requires moving application writes safely to the standby before promoting it. Previously, Heroku changed DATABASE\_URL and restarted app dynos, then waited for the old primary to shut down and replicate remaining writes, which could extend downtime during long-running transactions. The new method redirects new connections to the new primary, kills existing connections to the old primary, and relies on reconnections plus a rolling restart to prevent further writes there. Heroku reports HA maintenances now complete in 15–40 seconds instead of 60 seconds or more, and says the behavior is default for Premium, Private, and Shield plans.


### [Six Strategies for Deploying to Heroku](https://yomu.fyi/post/six-strategies-for-deploying-to-heroku.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Jason Skowronski
- Published: Jun 19, 2019
- Type: Explainer

Heroku offers six deployment strategies: Git push, GitHub integration, Review Apps, Docker, Terraform, and the “Deploy to Heroku” button. Each has different requirements and trade-offs, and strategies can be combined in a workflow. Git push is simple but requires a developer with access to both repository and app, while GitHub integration can automate deployments and block them until CI tests pass. Review Apps provide disposable instances for pull requests; Docker supplies self-contained environments but requires maintaining a stack and does not support pipeline promotions. Terraform uses declarative HCL to manage Heroku and external infrastructure despite lacking official Heroku support, and buttons offer one-click deployments from GitHub repositories but do not auto-update or connect deployed apps back to their repositories.


### [Reactive Programming with Salesforce Data](https://yomu.fyi/post/reactive-programming-with-salesforce-data.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Mars Hall
- Published: Feb 28, 2019
- Type: Explainer

Salesforce Platform Events and Change Data Capture enable custom applications to react to activity in Salesforce, motivating an event-sourced design for responsive, durable integrations. The article demonstrates a Node.js app on Heroku that consumes the Salesforce Streaming API through jsforce 1.9.0 or later, whose Faye-based streaming client handles authentication, network connectivity, and message callbacks. It notes that a basic subscription loses its position on restart and cannot coordinate parallel processing, then uses Redis to persist each topic’s Replay ID and distribute messages through pub/sub or reliable queues. Because the Salesforce Streaming API lacks consumer-group delivery, a singleton stream\_consumer feeds Redis while scalable web or worker processes handle work. The design also recommends a separate non-admin integration user and monitoring connection status, active clients, last message time, and processing duration.


### [Manage Real-time Event Streams and SQL Analytics with Apache Kafka on Heroku](https://yomu.fyi/post/manage-real-time-event-streams-and-sql-analytics-with-apache-kafka-on.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Vikram Rana
- Published: Dec 6, 2018
- Type: Tutorial

The post presents a Heroku-based system for handling high-volume product-usage events, combining near-real-time visualization with deeper SQL analytics. A Node.js producer sends simulated e-commerce events to an Apache Kafka topic, while a visualization consumer forwards selected data over WebSockets to a D3 stacked stream chart. A second consumer uses a Kafka consumer group, batches events, writes them to Amazon Redshift, and commits offsets after successful processing; Metabase then provides dashboards and ad-hoc SQL queries. The example uses Kafka, Redshift, and Metabase on Heroku, with Terraform described for provisioning Redshift and private connectivity, and notes that the setup incurs AWS and Heroku costs and requires Heroku Enterprise for that configuration. The source says the system can be provisioned on Heroku in 15 minutes.


### [Modern Web Stack: Rails 5 API, ActiveAdmin, and Create React App on Heroku](https://yomu.fyi/post/modern-web-stack-rails-5-api-activeadmin-and-create-react-app-on-herok.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Charlie Gleason
- Published: May 16, 2018
- Type: Tutorial

Modern Rails applications can combine a Rails 5 API-only backend, ActiveAdmin for CMS capabilities, and a Create React App frontend in one Heroku-hosted project. The tutorial addresses the tension between Rails API mode, which omits views and middleware, and ActiveAdmin’s need to serve HTML and use cookies, flash, sessions, and assets. It restores those pieces by switching ApplicationController to ActionController::Base, adding forgery protection and middleware, reintroducing sprockets, and defining a separate ApiController that retains ActionController::API. The frontend uses Create React App, API proxying during development, React Router for client-side routes, and a build process that serves the compiled app from Rails on Heroku, including a React 404 for unmatched paths. A smoothie-recipes example demonstrates the resulting setup.


### [Deconstructing Monolithic Apps with SHIFT Commerce](https://yomu.fyi/post/deconstructing-monolithic-apps-with-shift-commerce.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Ryan Townsend
- Published: Mar 13, 2018
- Type: Explainer

SHIFT Commerce describes its move from a monolithic application toward microservices, while arguing that architectural change should address concrete problems rather than follow fashion. The company identifies communication overhead, governance and high-risk deployments, and language or infrastructure limitations as reasons to extract functionality, including its Order Management Suite, admin panel, and integration system. SHIFT uses managed Apache Kafka on Heroku as an asynchronous event stream, with chronologically ordered, durable messages organized into topics so services can maintain local datasets. Its eight-step migration progressively adds producers, builds a consumer-backed database, tests and replicates logic, enables feature-flagged traffic, exchanges events, and removes deprecated monolith code. SHIFT reports more regular releases, lower latency on I/O-restricted API calls, and prevention of user-facing outages, while saying the migration remains ongoing.


### [Scaling ipify to 30 Billion Requests and Beyond on Heroku](https://yomu.fyi/post/scaling-ipify-to-30-billion-requests-and-beyond-on-heroku.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Randall Degges
- Published: Jan 23, 2018
- Type: Problem & solution

ipify began as a free API that returns a caller’s public-facing IP address, created to help discover cloud instances’ external addresses without management APIs. Its initial implementation was a sub-50-Loc Node service deployed on one Heroku dyno for about $7/month; rising usage caused slow responses and 503s. Investigation showed roughly 10 rps, while one Node process and string manipulation around X-Forwarded-For limited throughput; clustering doubled capacity, and the implementation later used Go. Heroku supplied load balancing, automatic restarts, and horizontal dyno scaling as traffic expanded through bursty demand and malicious use; the operator chose manual capacity rather than paid autoscaling. The service surpassed 30B requests per month, routinely serving 2k–20k RPS with 1–20ms average response times at $150–$200 monthly; ownership later passed to whoisxmlapi.com, whose work includes an improved UI and more data endpoint.


### [Kafka Streams on Heroku](https://yomu.fyi/post/kafka-streams-on-heroku.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Jeff Chao
- Published: Dec 19, 2017
- Type: Tutorial

Kafka Streams on Heroku shows how to organize, deploy, and scale Java stream-processing services using Kafka Streams, Apache Kafka, and the Heroku Runtime. The example contains a Text Processor that splits input from a textlines topic into words, an Aggregator that counts words in 10-second windows before writing to Postgres, and an independent Anomaly Detector that routes 10-second login-failure counts to urgent alerts or non-urgent email based on thresholds. A Gradle multi-project setup packages each service as an executable and uses a Procfile to run them as separate Heroku workers, while managed Kafka supplies the event-streaming infrastructure. Scaling is explained through Kafka partitions and Kafka Streams Stream Tasks: Stream Threads provide vertical scaling, dyno counts provide independent horizontal scaling, and Kafka Streams redistributes tasks when workers change or fail.


### [Jekyll on Heroku](https://yomu.fyi/post/jekyll-on-heroku.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Caleb Hearth
- Published: Dec 13, 2017
- Type: Tutorial

Jekyll can be deployed on Heroku to use its plugin system, but relying on jekyll serve would use Ruby’s single-threaded WEBrick rather than a production-oriented web server. The setup installs Ruby with ruby-install and chruby, then installs Bundler and Jekyll, creates a site, and tracks it in Git. Heroku’s official Ruby buildpack handles dependencies and runs a Rake assets:precompile task that executes jekyll build, while the Static buildpack serves the generated \_site/ directory according to static.json. The example pins Ruby 2.4.2, adds Rake, enables clean URLs and HTTPS, and completes with a successful deployment of the generated site to a Heroku URL.


### [In the Cloud, No One Can Hear Your OutOfMemoryError](https://yomu.fyi/post/in-the-cloud-no-one-can-hear-your-outofmemoryerror.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Joe Kutner
- Published: Oct 2, 2017
- Type: Announcement

Heroku introduces Heroku Exec and Language Runtime Metrics to improve production monitoring, inspection, and debugging for applications running on dynos. Heroku Exec creates secure TCP and SSH tunnels for SSH sessions, port forwarding, remote debugging, and diagnostic tools, while the Heroku Java CLI integrates jmap and VisualVM. A synthetic Java memory-leak example shows VisualVM tracking heap growth and jmap producing a downloadable HPROF heap dump that Eclipse Memory Analyzer identifies as Servlet-held FakeLeak objects. The metrics feature, enabled through the Heroku Metrics buildpack on paid Standard-or-above dynos, displays heap, non-heap, and garbage-collection activity in the dashboard through a Java agent using Prometheus; JVM-language support is generally available, while Go support is in beta.


### [Short Time Outs and Asynchronous Requests on Heroku](https://yomu.fyi/post/short-time-outs-and-asynchronous-requests-on-heroku.md)
- Company: [Heroku](https://yomu.fyi/company/heroku.md)
- Author: Damien Mathieu
- Published: Dec 5, 2014
- Type: Explainer

Heroku’s short request timeout and H12 errors reflect a scaling problem: standard web servers process queued requests serially, so one long operation can block others. The post separates slow server-side actions, such as video processing or PDF generation, from file uploads, and recommends background processes for the former and direct browser uploads to Amazon S3 or Google Cloud Storage for the latter. When a client must wait for completion, it describes polling or a WebSocket, noting that WebSocket connections close after 55 seconds of inactivity and ordinary pages still need to respond within 30 seconds. Avoiding lengthy web-process work improves performance and scalability; rack-timeout for Ruby or expressjs’ timeout for Node can terminate requests after a few seconds, with a recommended limit no higher than 10 seconds.


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