What is a good option for a Non-Blocking "Database" (Using a TCP Socket Server)

Question

In short I'm creating a socket server so I can add multiplayer support to my Flash game (Using Actionscript 3.0 Binary Socket on the Client-End).

I decided to go with Python since I'm the sole developer of the game/server and this will be my first non-blocking socket server. I was going to use Twisted but I deiced that I would use Python's asyncore (Asynchronous socket handler).

If I'm not mistaken connecting to a traditional database is a Blocking process. Since I'm trying to make this a non-blocking server I'm curious as to what solutions might be available to save permanent game related data?

Answer 1

I suggest you use any DB you like (sqlite comes with Python and will probably serve you well!): just have a dedicated thread that accesses said DB, taking requests from a Queue (and using another Queue, passed in as part of the request, to return results if needed). Threads aren't so bad if you have a small number, and they never share access to any structure or system that isn't read-only, communicating only by queues (which are intrinsically thread-safe).

Answer 2

Blocking (in traditional database terms, it's "locking") is inevitable if you want any form of consistency in your data.

Consistency as in "it is impossible for two gamers with distinct scores to both be declared as the winner".

Reducing the locking to a minimum is precisely one of those things in database design that turn it into an art form you (perhaps alas) only get to master after having screwed up so many times.