can i implement new load balancing algorithm in Nginx for test? i wanna try to implement one method for load balancing using content-based algorithm but i don't know how to use this implementation in my cluster
Now, this strikes me as a very interesting question, but it's too complex to possibly be answered here, I reckon.
I think you should get into the nginx community, who has their own wiki, IRC rooms, mailing lists etc, where you can talk to people who are deep into nginx and might be very helpful. Have you yet discovered the source code where load balancing is done? If you have, use the source code browser's ability to locate the people you might want to ask.
Getting in contact with the community behind an open source project has most of the times paid off well -- most projects have very helpful members that share a high level of enthusiasm, and getting to know the code by asking the people who wrote it is incredibly easy!