For the last few weeks I’ve been adding in two very important systems to Archaos – namely real-time communications via TCP, and the use of a database back-end for the server. The first makes games much more responsive, and allows the server to inform connected players of actions as and when they happen. It will also pave the way for an exciting addition I have planned, which will (hopefully) combat the inevitable pacing problems that arise from typical turn-based games. If you want to know more about what I’m getting at, give this excellent article a read.
The database server, client and game server respectively.
The second addition is a solid database-driven server. Until now, as a temporary solution I’d been storing all of the game data in a single file. When the server opened, it read all of the users and games from this file, and then stored all of the data in memory. If the data changed, the server would periodically save the entire file back to disk. The server would only write the data to disk if it had changed, and only once every so often – this kept writes to a minimum. The solution was fine for small scale testing, but it would not have scaled up well – quickly consuming all of the memory in the server machine, as well as being difficult to manage.
Now all of the data is stored on a mongoDB server in essentially the same format. The game server is then only responsible for the manipulation of the data, and not the storage and management of it. The game server itself is relatively simple in its approach; when a user sends an action, it loads the game, determines if the action can be performed, and if so what the outcomes are. It then saves the changed game back to the database and sends the actions to all of the connected players (which it does via TCP). The game server never keeps games, users, units or anything else in memory for longer than it needs to check or manipulate it. There are no special objects or instances; every function works only on the raw data. I may introduce some caching to reduce database operations later but at this stage the setup is fairly efficient.
So, I have what I feel is a solid base now, I’ve got some of the actions in and working (such as creating, joining and leaving games, unit movement and engagement) and now it’s just a case of writing the client-side stuff for the remaining actions, adding in the spell system and then getting it out there for public beta testing!
Look out soon for another post on the spell system and how I intend to tweak it to provide a more balanced start to each game.