Hydra Hot Potato Player (game)
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Hydra Hot Potato Player (game)

A variation on the children's classic game, Hot Potato. Adopted as a distributed computing example of network messaging using Hydra.

Read Building a Microservices Example Game with Distributed Messaging on the RisingStack community site.

Seeing this work

There are a few ways you can see this project working.

You can:

  • watch this quick video demo to see the game running across three machines on AWS.
  • or continue reading to build and run from the code in this repo.


Installation is simple, just npm install to pull the package dependencies.

$ npm install


This sample project has only one external dependency, a running instance of Redis. If you're new to Redis checkout this Redis quick start guide on YouTube.

You're free to run multiple instances of the Hot Potato Player on a single machine. However, it's a lot more fun to run multiple instances across a network of machines. If you try that, make sure your HPP instances and Redis are also network accessible.

Starting a game

Before you start a game, check the config object in the constructor of the hpp.js file. Make sure to update the Redis section with the location of your Redis instance.

"redis": {
  "url": "",
  "port": 6379,
  "db": 1

Note: The Redis credentials in the config/config.json file are no longer valid. You can visit RedisLabs to create your own free account or simply point to a local Redis server or one you have access to.

You can add a player to the game by:

$ node hpp.js John true

This adds a player called John who is also the one initially holding the potato.

You can add other players, but make sure to provide unique names to keep results clear.

$ node hpp.js Susan

On another shell tab or machine:

$ node hpp.js Jane

After a 15 second countdown the game begins and the potato is passed around. The game ends after another 30 seconds and the player left holding the potato is declared the loser.