使用C# MySQL Connector/Net连接LAN内MySQL服务器超时问题求助

环境信息 #

• MySQL版本：8.0.39
• 目标框架：.NET 4.8

测试连接代码 #

public bool TestConnection()
{
    try
    {
        MySqlConnectionStringBuilder builder = new MySqlConnectionStringBuilder
        {
            Server = Program.settings.MySqlServer,
            Port = Convert.ToUInt32(Program.settings.MySqlPort),
            UserID = Program.settings.MySqlUser,
            Password = Program.settings.MySqlPass,
            Database = Program.settings.MySqlDBName,
            //SslMode = MySqlSslMode.Disabled,
            //ConnectionProtocol = MySqlConnectionProtocol.Tcp,
            //Pooling = true
        };

        using (MySqlConnection cn = new MySqlConnection(builder.ConnectionString))
        {
            cn.Open();
        }
        return true;
    }
    catch (Exception ex)
    {
        Program.ErrorLog(ex.Message);
        return false;
    }
}

错误信息 #

顶层异常 #

Message: Unable to connect to any of the specified MySQL hosts.

内部异常 #

Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
The operation has timed out.

完整堆栈信息 #

MySql.Data.MySqlClient.MySqlException was caught
  HResult=-2147467259
  Message=Unable to connect to any of the specified MySQL hosts.
  Source=MySql.Data
  ErrorCode=-2147467259
  Code=0
  Number=1042
  StackTrace:
       at MySql.Data.MySqlClient.NativeDriver.<OpenAsync>d__38.MoveNext()
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
       at MySql.Data.MySqlClient.Driver.<OpenAsync>d__76.MoveNext()
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
       at MySql.Data.MySqlClient.Driver.<CreateAsync>d__74.MoveNext()
    --- End of stack trace from previous location where exception was thrown ---
       at MySql.Data.MySqlClient.Driver.<CreateAsync>d__74.MoveNext()
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
       at MySql.Data.MySqlClient.MySqlPool.<CreateNewPooledConnectionAsync>d__31.MoveNext()
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
       at MySql.Data.MySqlClient.MySqlPool.<GetPooledConnectionAsync>d__30.MoveNext()
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
       at MySql.Data.MySqlClient.MySqlPool.<TryToGetDriverAsync>d__34.MoveNext()
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
       at MySql.Data.MySqlClient.MySqlPool.<GetConnectionAsync>d__35.MoveNext()
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
       at MySql.Data.MySqlClient.MySqlConnection.<OpenAsync>d__94.MoveNext()
    --- End of stack trace from previous location where exception was thrown ---
       at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
       at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
       at MySql.Data.MySqlClient.MySqlConnection.Open()
       at ClickCardService.MySQL.Connection.TestConnection() in c:\Team_Click\ClickCardService\ClickCardService\MySQL\Connection.cs:line 103
  InnerException: MySql.Data.MySqlClient.MySqlException
       HResult=-2147467259
       Message=Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding.
       Source=MySql.Data
       ErrorCode=-2147467259
       Code=0
       Number=0
       StackTrace:
            at MySql.Data.Common.StreamCreator.<GetTcpStreamAsync>d__8.MoveNext()
         --- End of stack trace from previous location where exception was thrown ---
            at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            at MySql.Data.Common.StreamCreator.<GetStreamAsync>d__7.MoveNext()
         --- End of stack trace from previous location where exception was thrown ---
            at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
            at MySql.Data.MySqlClient.NativeDriver.<OpenAsync>d__38.MoveNext()
       InnerException: System.TimeoutException
            HResult=-2146233083
            Message=The operation has timed out.
            InnerException: 

连接字符串输出 #

server=192.168.0.21;port=3306;user id=r357;password=Pass1234;database=tidra2

已排查项 #

• TCP端口已开放，无防火墙限制
• Telnet连接服务器IP和端口成功
• Test-NetConnection 192.168.0.21 -Port 3306测试成功，结果：

ComputerName : 192.168.0.21
RemoteAddress : 192.168.0.21
RemotePort : 3306
InterfaceAlias : Ethernet
SourceAddress : 192.168.0.9
TcpTestSucceeded : True

• 本地通过phpMyAdmin可正常连接，配置：

/* Authentication type and info */
$cfg['Servers'][$i]['auth_type'] = 'config';
$cfg['Servers'][$i]['user'] = 'r357';
$cfg['Servers'][$i]['password'] = 'Pass1234';
$cfg['Servers'][$i]['extension'] = 'mysqli';
$cfg['Servers'][$i]['AllowNoPassword'] = true;
$cfg['Lang'] = '';

/* Bind to the localhost ipv4 address and tcp */
$cfg['Servers'][$i]['host'] = '192.168.0.21';
$cfg['Servers'][$i]['connect_type'] = 'tcp';

• 测试过多个版本MySQL Connector（8.4.0、8.3.0、8.0.33.1），问题依旧

最新日志信息 #

设置log-error-verbosity = 3后，MySQL错误日志记录：

2024-08-28T13:28:58.193475Z 10 [Note] [MY-010914] [Server] Got timeout reading communication packets

执行SHOW FULL PROCESSLIST结果：

Id, User, Host, db, Command, Time, State, Info
'12', 'unauthenticated user', 'PetarSPC:12325', NULL, 'Connect', '2', 'Receiving from client', NULL

MySQL通用日志中可看到phpMyAdmin的连接记录：

Timestamp, Thread, Command Type, Detail
2024-08-27 15:11:26.279050, 27, Connect, r357@PetarSPC on using TCP/IP

寻求解决思路。

内容的提问来源于stack exchange，提问作者Petar Stoyanov