For most Indie MMOs you can use a single server. You also store game state in memory and checkpoint it to disk like a DB, instead of having a DB as a bottleneck

For most Indie MMOs you can use a single server. You also store game state in memory and checkpoint it to disk like a DB, instead of having a DB as a bottleneck. This can scale to many hundreds of thousands of concurrent users if you do it right and it's easier than building a distributed system. Scaling it beyond that (you're very lucky!) then involves sharding, and you can build a master/slave system that splits shards and moved them around as needed. Source: working on my own MMO which is a realtime location based tower defense game. https://blog.winricklabs.com/(02-17-2020)---efficient-data-structures-for-mmo-game-backends-in-java.html https://blog.winricklabs.com/(02-17-2020)---efficient-data-s...