Do we really need an array? Lets see..
* Lets say we have three mirrors X (45 Mb), Y (5Mb), Z (3Mb)
* =>Total bandwidth = 53Mb
* Now lets say, at any given instance there are 100 requests.
* So proportionally, X should get (100/53)*45 = 85 requests. Y should get 9 requests and Z, 6 requests only.
Now
1. Generate a random no r. 2. If r<85 route to X, else if 85<r<95 route to Y else route to Z.
This will do the job.