简单hash 取模算法,均衡度可以

        /// <summary>
        /// 获取一个key的Md5 Hash值
        /// </summary>
        /// <param name="key"></param>
        /// <returns></returns>
        public int HashCode(string key)
        {
            int HashCode;
            byte[] Md5Bype;
            if (Md5Cache.ContainsKey(key))
            {
                return Md5Cache[key];
            }
            else
            {
                using (var md5 = new MD5CryptoServiceProvider())
                {
                    Md5Bype = md5.ComputeHash(Encoding.UTF8.GetBytes(key));
                }
                HashCode = BitConverter.ToInt32(Md5Bype, 0);
                if (HashCode < 0)
                {
                    HashCode = int.MaxValue + HashCode;
                }

                HashCode = Math.Abs(HashCode);
                Md5Cache[key] = HashCode;
            }
            return HashCode;
        }



        /// <summary>
        /// 是否是当前节点
        /// </summary>
        public int BeloneNode(string key)
        {
            return HashCode(key) % NodeCount;
        }