I'm developing a game server for an online game, and I have some questions regarding how to handle threading from the network layer to the main loop. Some of the articles I have read regarding high performance servers actually raised the questions I'm about to ask. Here are the two articles if anyone is interested:
My main concern after reading these articles is the context switching. I've previously developed a prototype game server using python using microthreads/green threads to avoid context switches (to a large extent anyway). In this prototype I used two processes where they shared a msg queue. The network process would enter a message into the queue and then wait (its really one of the green threads waiting,..) for the game loop process to finish its processing. Once the game loop is finished it notifies the waiting green threads about the result (this has to be done, because the client expects a new state and a result from the previous operation). This sending of messages back and forth between processes/threads is one of the items the first articles discusses as a performance killer for servers. My question is now how to best remedy the situation when I'm developing the real server using C# 5.0.
The articles describes a way to remedy the situation of too many context switches by allowing the same thread that handles the incoming network connection to also take care of the processing and then send back result to client. In this model we may have say 10-15 threads (just a suggestion), waiting for a connection on the network side, once a connection has been established and message received, the thread turns into a worker. The worker then tries to aquire a lock (shared by the 10-15 network threads), and processes the message and sends back result. Afterwards the lock is released and the thread waits for next connection etc.
Does anyone have any experience with this kind of setup? Pros/Cons? One of the obvious pros is the ease of knowing who sender/receiver is as you're responsible for the current connection.
My goal is to be able to serve 50k messages/second. The game is not heavy when it comes to math, so the game loop won't have an issue crunching 50k messages/second. I'm more concerned with the network issue...
Thanks in advance!