load balance method

load_balance.py

def make_balance_list(servers):
    whole_weight = sum(srv[1] for srv in servers)
    balance = []
    weight_so_far = 0
    for server in servers:
        weight = server[1]
        weight_so_far += weight
        balance.append(weight_so_far / whole_weight)
    return balance


def choose_server(servers, balance):
    import random
    import bisect
    idx = bisect.bisect(balance, random.random())
    return servers[idx][0]


if __name__ == '__main__':
    # test
    servers = [
        ('192.168.0.101', 1),
        ('192.168.0.102', 2),
    ]

    balance = make_balance_list(servers)
    res = [choose_server(servers, balance) for _ in range(10000)]

    import collections
    counter = collections.Counter(res)
    print(counter)