https://github.com/paustint/socketio-node-cluster-test

Proof of Concept to show Heroku cannot handle sticky worker sessions with Node Cluster
https://github.com/paustint/socketio-node-cluster-test

cluster code-cluster heroku node session socket-io socketio sticky sticky-session

Last synced: 25 days ago
JSON representation

Proof of Concept to show Heroku cannot handle sticky worker sessions with Node Cluster

• Host: GitHub
• URL: https://github.com/paustint/socketio-node-cluster-test
• Owner: paustint
• Created: 2019-07-14T15:58:07.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2023-01-05T20:53:19.000Z (almost 2 years ago)
• Last Synced: 2023-08-03T22:27:45.511Z (over 1 year ago)
• Topics: cluster, code-cluster, heroku, node, session, socket-io, socketio, sticky, sticky-session
• Language: JavaScript
• Size: 3.53 MB
• Stars: 1
• Watchers: 1
• Forks: 0
• Open Issues: 32
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

        
# Heroku / Node Cluster / Socket.io Test

This is a proof of concept application to prove that Heroku cannot handle socket.io polling transports while using Node clusters.

(I thought it would not work, but turns our that it did work....)

The problem is that all the "sticky session" solutions have all of the workers using a random port on their server.listen(), and Heroku blocks all ports aside from `process.env.PORT`.

**The source code was originally built here**: https://github.com/ANURAGVASI/socket.io-multiserver-chatApp

**Accompanying blog article**: https://blog.imaginea.com/7597-2/

Summary of the issue:

1. For any heroku app that has at least 1 2x Dyno, two+ workers will be created (this can be simulated by creating two socket)

   1. Override the `WEB_CONCURRENCY` environment variable to `3` or higher to allow workers on any dyno size

2. Because socket.io uses many http requests for a handshake or long polling transport, the same worker must handle all requests

   1. Note: this library has set the transport to `['polling']` to force the simulation of browsers or networks without websocket support

You can run this locally to confirm it is working

```shell

npm run build

npm start

```

[![Deploy](https://www.herokucdn.com/deploy/button.svg)](https://heroku.com/deploy)