Scheduling load with a round robin algorithm?

Question

I need to write a round robin algorithm to schedule load to n endpoints?

So if I have servers A, B and C

I wanted to make sure to round-robin through them for each request I get. How do I do this in C#?

Answer 1

Just for the record, definition of round robin:

http://en.wikipedia.org/wiki/Round-robin_scheduling

Just use a queue. Take one off of the top, use it and put it back. This ensures that the most recent one used will always be the last one to be picked up.

Queue<Server> q = new Queue<Server>();

//get the next one up
Server s = q.DeQueue();


//Use s;


//put s back for later use.
q.Enqueue(s);

Link to the queue class:

http://msdn.microsoft.com/en-us/library/7977ey2c.aspx

Answer 2

If your endpoints are accessed through a List or Array, you only need to increment an index in a circular fashion:

public class RoundRobinIndex
{
    volatile int index = 0;
    int count;

    public int Next
    {
        get
        {
            if (index == count)
            {
                index = 0;
            } 
            return index++;
        }
    }

    public RoundRobinIndex(int countArg)
    {
        count = countArg;
    }
}