hrw

// given a set of servers
servers := map[int]string{
	1: "one.example.com",
	2: "two.example.com",
	3: "three.example.com",
	4: "four.example.com",
	5: "five.example.com",
	6: "six.example.com",
}

// which can be mapped to integer values
ids := make([]int, 0, len(servers))
for id := range servers {
	ids = append(ids, id)
}

// HRW can consistently select a uniformly-distributed set of servers for
// any given key
key := []byte("/examples/object-key")
for _, id := range TopN(ids, key, 3) {
	fmt.Printf("trying GET %d %s%s\n", id, servers[id], key)
}

Output:

trying GET 1 one.example.com/examples/object-key
trying GET 3 three.example.com/examples/object-key
trying GET 5 five.example.com/examples/object-key