利用RabbitMQ、MySQL实现超大用户级别的消息在/离线收发
由于RabbitMQ中只有队列（queue）才能存储信息，所以用RabbitMQ实现超大用户级别（百万计）的消息在/离线收发需要对每一个用户创建一个永久队列。
但是RabbitMQ节点内存有限，经测试后发现节点集群也无法满足数百万用户队列收发数据的要求，所以最终决定采用数据库辅助实现该功能。
一、数据库结构
user_list数据库下有4张表：user_info、group_info、groupmember_info、message_info。
user_info表中含有username（主键，非空，VARCHAR(50)）、password(非空，VARCHAR(50))、routingkey（非空，VARCHAR(50)）、has_queue（INT UNSIGNED）四个字段。
group_info表中含有groupname（主键，非空，VARCHAR(50)）、password(非空，VARCHAR(50))、creator（非空，VARCHAR(50)）三个字段。
groupmember_info表中含有username（主键，非空，VARCHAR(50)）、groupname（主键，非空，VARCHAR(50)）两个字段。
message_info表中含有sendtime（非空，VARCHAR(50)）、body（非空，VARCHAR(300)），receiver（非空，VARCHAR(50)）、sender（非空，VARCHAR(100)）四个字段。
二、客户端结构
1、文件夹创建以及包依赖安装：
dotnet new console --name Client
mv Client/Program.cs Client/Client.cs
cd Client
dotnet add package RabbitMQ.Client
dotnet add package MySql.Data
dotnet restore 2、项目结构 Client.cs(主程序):
using RabbitMQ.Client;
using MySql.Data.MySqlClient; namespace Client
{
class Client
{
static void Main(string[] args)
{
// 连接数据库
string connStr = "Database=user_list;datasource=127.0.0.1;port=3306;user=root;pwd=123456;";
MySqlConnection sqlConn = new MySqlConnection(connStr); sqlConn.Open(); // 连接RabbitMQ
var factory = new ConnectionFactory() { HostName = "dev.corp.wingoht.com", VirtualHost = "cd", UserName = "ishowfun", Password = "" };
using (var connection = factory.CreateConnection())
using (var channel = connection.CreateModel())
{
// 用户登录，并获取离线消息
UserInfo user = UserLogin.Login(sqlConn); // 监听在线消息
Consumer.StartListening(channel, sqlConn, user); // 监听按钮事件，调用不同的客户端功能
KeyListening.StartListening(channel, sqlConn, user); // 退出登录
UserLogout.Logout(channel, sqlConn, user);
} // 释放数据库连接
sqlConn.Close();
}
}
}
UserLogin.cs:
using System;
using MySql.Data.MySqlClient; namespace Client
{
class UserLogin
{
public static UserInfo Login(MySqlConnection conn)
{
UserInfo user = new UserInfo(); // 用户名输入
Console.Write("Please enter your username: ");
user.Username = Console.ReadLine();
while (user.Username.Contains(",") || user.Username.Contains(" "))
{
Console.WriteLine("Error: Username can not contain \",\"! and \" \"");
Console.Write("Please enter your username again: ");
user.Username = Console.ReadLine();
} MySqlCommand cmd = new MySqlCommand("select * from user_info where username='" + user.Username + "'", conn);
MySqlDataReader reader = cmd.ExecuteReader(); // 判断该用户是否已经注册
if (reader.Read())
{
// 已注册用户登录
user.IsNewUser = true; // 验证密码
Console.Write("Please enter your password: ");
user.Password = reader.GetString("password");
while (user.Password != Console.ReadLine())
{
Console.WriteLine("Error: Username and password do not match!");
Console.Write("Please enter your password again: ");
}
Console.WriteLine("Welcome back, {0}!", user.Username);
Console.WriteLine("-------------------------------------"); // 获取当前用户的路由键
user.RoutingKey = reader.GetString("routingkey");
reader.Close(); // 读取离线消息
cmd = new MySqlCommand("select * from message_info where receiver='" + user.Username + "'", conn);
reader = cmd.ExecuteReader();
Console.WriteLine("Unread Message: ");
while (reader.Read())
{
string sender = reader.GetString("sender");
string sendTime = reader.GetString("sendtime");
string content = reader.GetString("body");
string[] splitSender = sender.Split(" ");
if (splitSender.Length == )
{
Console.WriteLine("Sender: {0}, SendTime: {1}, Content: {2}", sender, sendTime, content);
}
else
{
sender = splitSender[];
string group = splitSender[];
Console.WriteLine("Sender: {0} from {1}, SendTime: {2}, Content: {3}", sender, group, sendTime, content);
}
}
reader.Close(); // 删除已处理的离线消息
cmd = new MySqlCommand("delete from message_info where receiver=@re", conn);
cmd.Parameters.AddWithValue("re", user.Username); cmd.ExecuteNonQuery();
}
else
{
// 新用户注册并登录
user.IsNewUser = false;
reader.Close();
Console.WriteLine("Welcome, new user!"); // 设置密码
Console.Write("Please set your password: ");
user.Password = Console.ReadLine();
Console.Write("Please confirm your password: ");
while (user.Password != Console.ReadLine())
{
Console.WriteLine("Error: Confirmation failure!");
Console.Write("Please set your password again: ");
user.Password = Console.ReadLine();
Console.Write("Please confirm your password: ");
} // 生成该用户的加密路由键，并保证该路由键唯一
user.RoutingKey = GenerateKey.GenerateRandomString();
cmd = new MySqlCommand("select * from user_info where routingkey='" + user.RoutingKey + "'", conn);
reader = cmd.ExecuteReader();
while (reader.Read())
{
reader.Close();
user.RoutingKey = GenerateKey.GenerateRandomString();
reader = cmd.ExecuteReader();
} reader.Close();
} Console.WriteLine("-------------------------------------");
return user;
}
}
}
UserInfo.cs:
namespace Client
{
class UserInfo
{
// 唯一用户名
public string Username { get; set; } // 登录密码
public string Password { get; set; } // 加密路由键
public string RoutingKey { get; set; } // 是否为新用户
public bool IsNewUser { get; set; }
}
}
GenerateKey.cs:
using System; namespace Client
{
class GenerateKey
{
// 字符串中字符的取值范围
private static char[] constant =
{
'','','','','','','','','','',
'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',
'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'
}; // 生成指定长度的随机字符串
public static string GenerateRandomString(int len)
{
System.Text.StringBuilder newRandom = new System.Text.StringBuilder();
Random rd = new Random();
for (int i = ; i < len; i++)
{
newRandom.Append(constant[rd.Next()]);
}
return newRandom.ToString();
}
}
}
Consumer.cs:
using System;
using System.Text; using RabbitMQ.Client;
using RabbitMQ.Client.Events;
using MySql.Data.MySqlClient; namespace Client
{
class Consumer
{
public static void StartListening(IModel channel, MySqlConnection conn, UserInfo user)
{
// 交换机声明
channel.ExchangeDeclare(exchange: "topic_message", type: "topic"); // 队列创建与绑定
channel.QueueDeclare(queue: user.RoutingKey,
durable: true,
exclusive: false,
autoDelete: false,
arguments: null); channel.QueueBind(queue: user.RoutingKey,
exchange: "topic_message",
routingKey: user.RoutingKey); var consumer = new EventingBasicConsumer(channel); // 处理收到的消息
consumer.Received += (model, ea) =>
{
var body = ea.Body;
string message = Encoding.UTF8.GetString(body);
string[] splitRes = message.Trim().Split(",");
string sendTime = splitRes[];
string content = splitRes[];
string[] splitSender = splitRes[].Split(" ");
if (splitRes.Length > )
{
for (int i = ; i < splitRes.Length; i++)
content = content + "," + splitRes[i];
} Console.WriteLine();
if (splitSender.Length == )
{
string sender = splitRes[];
Console.WriteLine("Sender: {0}, SendTime: {1}, Content: {2}", sender, sendTime, content);
}
else
{
string sender = splitSender[];
string group = splitSender[];
Console.WriteLine("Sender: {0} from {1}, SendTime: {2}, Content: {3}", sender, group, sendTime, content);
}
}; channel.BasicConsume(queue: user.RoutingKey,
autoAck: true,
consumer: consumer); MySqlCommand cmd; // 更新数据库
if (user.IsNewUser)
{
// 向数据库声明该用户已经拥有了队列，可以直接在线发送
cmd = new MySqlCommand("update user_info set has_queue=1 where username=@uid", conn);
cmd.Parameters.AddWithValue("uid", user.Username); cmd.ExecuteNonQuery();
}
else
{
// 防止注入地插入新用户数据
cmd = new MySqlCommand("insert into user_info set username=@uid,password=@pwd,routingkey=@rk,has_queue=1", conn);
cmd.Parameters.AddWithValue("uid", user.Username);
cmd.Parameters.AddWithValue("pwd", user.Password);
cmd.Parameters.AddWithValue("rk", user.RoutingKey); cmd.ExecuteNonQuery();
} Console.WriteLine("{0} Start Listening!", user.Username);
Console.WriteLine("-------------------------------------");
}
}
}
KeyListening.cs:
using System; using RabbitMQ.Client;
using MySql.Data.MySqlClient; namespace Client
{
class KeyListening
{
public static void StartListening(IModel channel, MySqlConnection conn, UserInfo user)
{
MQHelper.HelpTip();
Console.WriteLine("-------------------------------------");
ConsoleKeyInfo keyPressed;
bool escFlag = false; while (true)
{ keyPressed = Console.ReadKey();
Console.WriteLine();
Console.WriteLine("-------------------------------------");
switch (keyPressed.Key)
{
// 0: 显示帮助信息
case ConsoleKey.D0:
MQHelper.HelpTip();
break;
// 1: 创建群组
case ConsoleKey.D1:
MQHelper.CreateGroup(conn, user);
break;
// 2: 申请加入群组
case ConsoleKey.D2:
MQHelper.JoinGroup(conn, user);
break;
// 3: 退出群组
case ConsoleKey.D3:
MQHelper.LeaveGroup(conn, user);
break;
// 4: 显示群组信息
case ConsoleKey.D4:
MQHelper.ShowGroup(conn, user);
break;
// 5: 单播
case ConsoleKey.D5:
MQHelper.BasicSend(channel, conn, user);
break;
// 6: 组播
case ConsoleKey.D6:
MQHelper.GroupSend(channel, conn, user);
break;
// ESC: 退出
case ConsoleKey.Escape:
escFlag = true;
break;
// 无意义按键
default:
Console.WriteLine("Error: Invalid press!");
break;
} Console.WriteLine("-------------------------------------"); if (escFlag)
break;
}
}
}
}
MQHelper.cs:
using System;
using System.Text;
using System.Collections.Generic; using RabbitMQ.Client;
using MySql.Data.MySqlClient; namespace Client
{
// 该类包含了按钮监听事件触发的各项功能的实现
class MQHelper
{
#region 显示帮助信息
public static void HelpTip()
{
// 显示各按键对应功能
Console.WriteLine("Function Press:");
Console.WriteLine("[0]: Help");
Console.WriteLine("[1]: Create group");
Console.WriteLine("[2]: Join group");
Console.WriteLine("[3]: Leave group");
Console.WriteLine("[4]: Show groups");
Console.WriteLine("[5]: BasicSend");
Console.WriteLine("[6]: GroupSend");
Console.WriteLine("[ESC]: Log out");
}
#endregion #region 创建群组
public static void CreateGroup(MySqlConnection conn, UserInfo user)
{
// 设置群组名称以及加入密码
Console.Write("Please set the group name: ");
string groupName = Console.ReadLine();
MySqlCommand groupCmd = new MySqlCommand("select * from group_info where groupname='" + groupName + "'", conn);
MySqlDataReader groupReader = groupCmd.ExecuteReader(); if (groupReader.Read())
{
groupReader.Close();
Console.WriteLine("Error: This group name already exists!");
}
else
{
groupReader.Close(); Console.Write("Please set the password: ");
string pwd = Console.ReadLine();
Console.Write("Please confirm the password: ");
while (pwd != Console.ReadLine())
{
Console.WriteLine("Error: Confirmation failure!");
Console.Write("Please set the password again: ");
pwd = Console.ReadLine();
Console.Write("Please confirm the password: ");
} // 将群组信息插入数据库
groupCmd = new MySqlCommand("insert into group_info set groupname=@gid,password=@pwd,creator=@cr", conn);
groupCmd.Parameters.AddWithValue("gid", groupName);
groupCmd.Parameters.AddWithValue("pwd", pwd);
groupCmd.Parameters.AddWithValue("cr", user.Username); groupCmd.ExecuteNonQuery(); groupCmd = new MySqlCommand("insert into groupmember_info set groupname=@gid,username=@uid", conn);
groupCmd.Parameters.AddWithValue("gid", groupName);
groupCmd.Parameters.AddWithValue("uid", user.Username); groupCmd.ExecuteNonQuery(); Console.WriteLine("Successfully create the group!");
}
}
#endregion #region 申请加入群组
public static void JoinGroup(MySqlConnection conn, UserInfo user)
{
// 输入要加入的群名
Console.Write("Please enter the group name: ");
string groupName = Console.ReadLine();
MySqlCommand groupCmd = new MySqlCommand("select * from group_info where groupname='" + groupName + "'", conn);
MySqlDataReader groupReader = groupCmd.ExecuteReader(); // 判断该群是否存在
if (groupReader.Read())
{
// 验证加入密码
string pwd = groupReader.GetString("password");
groupReader.Close(); Console.Write("Please enter your password: ");
if (pwd != Console.ReadLine())
{
Console.WriteLine("Error: Username and password do not match!");
}
else
{
groupCmd = new MySqlCommand("select * from groupmember_info where groupname='" + groupName + "' and username='" + user.Username + "'", conn);
groupReader = groupCmd.ExecuteReader(); // 判断该用户是否已经在这个群中
if (groupReader.Read())
{
groupReader.Close();
Console.WriteLine("Error: You already join the group!");
}
else
{
// 加入该群，并更新数据库信息
groupReader.Close();
groupCmd = new MySqlCommand("insert into groupmember_info set groupname=@gid,username=@uid", conn);
groupCmd.Parameters.AddWithValue("gid", groupName);
groupCmd.Parameters.AddWithValue("uid", user.Username); groupCmd.ExecuteNonQuery();
Console.WriteLine("Successfully join the group!");
}
}
}
else
{
groupReader.Close();
Console.WriteLine("Error: This group name does not exist!");
}
}
#endregion #region 退出群组
public static void LeaveGroup(MySqlConnection conn, UserInfo user)
{
// 输入要退出群的名称
Console.Write("Please enter the group name: ");
string groupName = Console.ReadLine();
MySqlCommand groupCmd = new MySqlCommand("select * from groupmember_info where groupname='" + groupName + "' and username='" + user.Username + "'", conn);
MySqlDataReader groupReader = groupCmd.ExecuteReader(); // 判断你是否在这个群中
if (groupReader.Read())
{
// 退出该群，并更新数据库信息
groupReader.Close();
groupCmd = new MySqlCommand("delete from groupmember_info where groupname=@gid and username=@uid", conn);
groupCmd.Parameters.AddWithValue("gid", groupName);
groupCmd.Parameters.AddWithValue("uid", user.Username);
groupCmd.ExecuteNonQuery();
Console.WriteLine("Successfully leave the group!");
}
else
{
groupReader.Close();
Console.WriteLine("Error: You didn't join the group!");
}
}
#endregion #region 显示群组信息
public static void ShowGroup(MySqlConnection conn, UserInfo user)
{
MySqlCommand groupCmd = new MySqlCommand("select * from groupmember_info where username='" + user.Username + "'", conn);
MySqlDataReader groupReader = groupCmd.ExecuteReader(); // 显示加入的所有群名称
while (groupReader.Read())
{
Console.WriteLine(groupReader.GetString("groupname"));
}
groupReader.Close();
}
#endregion #region 单播
public static void BasicSend(IModel channel, MySqlConnection conn, UserInfo user)
{
// 输入收信人用户名
Console.Write("Please enter the receiver: ");
string receiver = Console.ReadLine();
Console.WriteLine("-------------------------------------"); // 输入待发送的消息
Console.WriteLine("Please enter the message: ");
string content = Console.ReadLine();
Console.WriteLine("-------------------------------------");
MySqlCommand sendCmd = new MySqlCommand("select * from user_info where username='" + receiver + "'", conn);
MySqlDataReader sendReader = sendCmd.ExecuteReader(); bool user_flag = sendReader.Read(); // 判断是否存在该收信人
if (user_flag)
{
string receiverKey = sendReader.GetString("routingkey");
int hasQueue = sendReader.GetInt32("has_queue");
string sendTime = DateTime.Now.ToString();
string message = user.Username + "," + sendTime + "," + content;
var body = Encoding.UTF8.GetBytes(message); sendReader.Close(); // 目标队列存在，则直接发布信息；否则将信息数据存入数据库
if (hasQueue == )
{
// 在线发布消息
var properties = channel.CreateBasicProperties();
properties.Persistent = true; channel.BasicPublish(exchange: "topic_message",
routingKey: receiverKey,
basicProperties: properties,
body: body);
}
else
{
// 离线发布消息
sendCmd = new MySqlCommand("insert into message_info set sendtime=@st,body=@body,receiver=@re,sender=@se", conn);
sendCmd.Parameters.AddWithValue("st", sendTime);
sendCmd.Parameters.AddWithValue("body", content);
sendCmd.Parameters.AddWithValue("re", receiver);
sendCmd.Parameters.AddWithValue("se", user.Username); sendCmd.ExecuteNonQuery();
}
Console.WriteLine("You sent [ {0} ] to {1} at {2}.", content, receiver, sendTime);
}
else
{
sendReader.Close();
Console.WriteLine("Error: The receiver does not exist!");
}
}
#endregion #region 组播
public static void GroupSend(IModel channel, MySqlConnection conn, UserInfo user)
{
// 输入在那个群组中发布消息
Console.Write("Please enter the receiver: ");
string group = Console.ReadLine();
Console.WriteLine("-------------------------------------"); // 输入待发布消息
Console.WriteLine("Please enter the message: ");
string content = Console.ReadLine();
Console.WriteLine("-------------------------------------"); // 读取群组中的所有成员
MySqlCommand sendCmd = new MySqlCommand("select * from groupmember_info where groupname='" + group + "'", conn);
MySqlDataReader sendReader = sendCmd.ExecuteReader();
List<string> memberList = new List<string>();
while (sendReader.Read())
{
memberList.Add(sendReader.GetString("username"));
}
sendReader.Close(); string sender = user.Username + " " + group;
string sendTime = DateTime.Now.ToString(); // 交换机声明
channel.ExchangeDeclare(exchange: "topic_message", type: "topic"); var properties = channel.CreateBasicProperties();
properties.Persistent = true; // 逐个处理成员，在线用户在线发送消息，离线用户离线发送消息
foreach (string member in memberList)
{
sendCmd = new MySqlCommand("select * from user_info where username='" + member + "'", conn);
sendReader = sendCmd.ExecuteReader(); sendReader.Read();
string receiverKey = sendReader.GetString("routingkey");
int hasQueue = sendReader.GetInt32("has_queue");
string message = sender + "," + sendTime + "," + content;
var body = Encoding.UTF8.GetBytes(message);
sendReader.Close(); // 目标队列存在，则直接发布信息；否则将信息数据存入数据库
if (hasQueue == )
{
// 在线发送消息
channel.BasicPublish(exchange: "topic_message",
routingKey: receiverKey,
basicProperties: properties,
body: body);
}
else
{
// 离线发送消息
sendCmd = new MySqlCommand("insert into message_info set sendtime=@st,body=@body,receiver=@re,sender=@se", conn);
sendCmd.Parameters.AddWithValue("st", sendTime);
sendCmd.Parameters.AddWithValue("body", content);
sendCmd.Parameters.AddWithValue("re", member);
sendCmd.Parameters.AddWithValue("se", sender); sendCmd.ExecuteNonQuery();
}
} Console.WriteLine("You sent [ {0} ] to {1} at {2}.", content, group, sendTime);
}
#endregion
}
}
UserLogout.cs:
using System; using RabbitMQ.Client;
using MySql.Data.MySqlClient; namespace Client
{
class UserLogout
{
public static void Logout(IModel channel, MySqlConnection conn, UserInfo user)
{
Console.WriteLine("Goodbye, {0}!", user.Username); // 删除队列，并更新数据库，表明后面发送的消息应该转为离线发送
channel.QueueDelete(user.RoutingKey);
MySqlCommand cmd = new MySqlCommand("update user_info set has_queue=0 where username=@uid", conn);
cmd.Parameters.AddWithValue("uid", user.Username); cmd.ExecuteNonQuery();
}
}
}
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