python3 一致性hash算法

量少的场景, 一致性hash不均匀的问题很难解决，加500个虚拟节点也不是很管用

算法很简单，自己用函数写了一下，仅供参考：

python3代码展示：

import hashlibserver_ip_list = ["192.168.1.10", "192.168.2.20", "192.168.3.30","192.168.4.40"]client_ip_list = ["113.88.97.173", "106.11.154.33", "207.46.13.149","42.156.137.120", "203.208.60.0", "119.39.47.182", "171.34.179.4", "111.175.58.52", "124.235.138.199","175.184.166.184","111.175.58.52", "124.235.18.119","175.144.163.124","175.14.166.114","111.175.8.152", "124.23.18.113","175.144.13.116"]def get_md5(data): m = hashlib.md5() m.update(data.encode('utf-8')) return m.hexdigest()def get_ip(): virtual_nodes = 500 node_dict = {} # 遍历服务器ip，生成对应的虚拟结点 for serverip in server_ip_list: for i in range(virtual_nodes): # serverip加上一些动态参数生成md5值 hash_key = get_md5(str('{0}VN{1}'.format(serverip,i))) node_dict[hash_key]=serverip # 将node_dict字典按key排序生成列表 sorted_key_list = sorted(node_dict) # 将node_dict字典按key排序 node_dict = sorted(node_dict.items(),key=lambda d:d[0],reverse=False) #print(node_dict) #print(sorted_key_list) for clientip in client_ip_list: selected_key_list = [] # clientip生成md5值 hc = get_md5(str(clientip)) #print(hc) switch = 0 for key in sorted_key_list: #print(key) # clientip和sorted_key_list中的md5值做比较，clientip的md5值小于等于sorted_key_list中的md5值,switch=1 if hc <= key: selected_key_list.append(key) switch=1 if switch == 0: firstkey = sorted_key_list[0] else: firstkey = selected_key_list[0] #print(firstkey) #print(selected_key_list) print("{0}请求的服务器ip为:{1}".format(clientip,dict(node_dict)[firstkey]))# for i in range(2):get_ip()

执行结果：

113.88.97.173请求的服务器ip为:192.168.2.20106.11.154.33请求的服务器ip为:192.168.4.40207.46.13.149请求的服务器ip为:192.168.3.3042.156.137.120请求的服务器ip为:192.168.3.30203.208.60.0请求的服务器ip为:192.168.3.30119.39.47.182请求的服务器ip为:192.168.3.30171.34.179.4请求的服务器ip为:192.168.4.40111.175.58.52请求的服务器ip为:192.168.1.10124.235.138.199请求的服务器ip为:192.168.3.30175.184.166.184请求的服务器ip为:192.168.3.30111.175.58.52请求的服务器ip为:192.168.1.10124.235.18.119请求的服务器ip为:192.168.2.20175.144.163.124请求的服务器ip为:192.168.2.20175.14.166.114请求的服务器ip为:192.168.4.40111.175.8.152请求的服务器ip为:192.168.2.20124.23.18.113请求的服务器ip为:192.168.1.10175.144.13.116请求的服务器ip为:192.168.4.40