Building a Matchmaking system for 1v1 competitive games using Redis
Matcha works using an API for user management and entering the queue and a worker for finding matches between players.
The API allows users to be added to the Redis database and also allows users to queue up for a match.
The API uses the following commands:
JSON.SETis used to add a player and to update a user's rating when a game is finished.JSON.NUMINCRBYis used to update the user's game played counter when a game is finished.JSON.GETis used to retrieve a user from the database using it's ID.ZADDis used to add a user to the queue.SUBSCRIBEis used to listen for matches found by the worker.UNSUBSCRIBEis used when a match is found for a user to clean up.
Loop over all players and look for potential opponents. Publish a match when 2 opponents have been found within eachothers ELO-range.
The longer a player is queueing the bigger his ELO-range will be. It's important that a when a possible opponent is found that the player is also in the opponents player's ELO-range, this gives more balanced matches. It's also possible to cap out the ELO-range as to not get extreme ELO differences between players.
The worker runs every 10 seconds and uses the following commands:
ZSCANis used to get all players currently in the queue.ZSCOREis used to get a player from the queue and to see how long he has been in the queue.ZRANGEBYSCOREis used to get all players within an ELO-range to find possible opponents.ZREMis used to remove the players from the queue when a match has been found.PUBLISHis used to publish the match info to the API when a match is found.
docker-compose up -d- If
debugmode is active you can go to http://0.0.0.0:8000/index.html to test the server.
Using the MATCHA_ENVIRONMENT you can enable/disable the testing page. When the variable is set to debug, the test page will be available at /index.html