After deploying the virtual world, the user base will keep growing. When the virtual world spreads and gets popular, the increasing traffic and large amount of simultaneous player connections may push the limit of the server capacity. Hence, we will need to scale up the backend infrastructure at that time.

When scaling up the backend with multiple server instances, we need to set up some load balancing mechanisms. We may either create parallel instances of the virtual world or extend the virtual world with clustering technology.

The article Building MMO Virtual Worlds from SmartFoxServer documentation provides a comprehensive guide to scale up the SmartFoxServer-based virtual worlds (http://smartfoxserver.com/docs/docPages/articles/build_mmo_p2.htm ).