Question

我期待非常令人沮丧的问题，找不到理由。

有一个托管在Azure上的应用程序，它使用MySQL数据库。我正在使用Oracle的MySQL.Data nuget（6.10.5）。我经常遇到Timeout过期错误，无法连接到任何指定的MySQL主机（每24小时打十几次）。

Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding.
Exception Details: MySql.Data.MySqlClient.MySqlException: Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding.

堆栈追踪：

    [MySqlException (0x80004005): Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding.]
   MySql.Data.Common.StreamCreator.GetTcpStream(MySqlConnectionStringBuilder settings) +177
   MySql.Data.Common.StreamCreator.GetStream(MySqlConnectionStringBuilder settings) +37
   MySql.Data.MySqlClient.NativeDriver.Open() +55

[MySqlException (0x80004005): Unable to connect to any of the specified MySQL hosts.]
   MySql.Data.MySqlClient.NativeDriver.Open() +151
   MySql.Data.MySqlClient.Driver.Open() +50
   MySql.Data.MySqlClient.Driver.Create(MySqlConnectionStringBuilder settings) +225
   MySql.Data.MySqlClient.MySqlPool.CreateNewPooledConnection() +15
   MySql.Data.MySqlClient.MySqlPool.GetPooledConnection() +288
   MySql.Data.MySqlClient.MySqlPool.TryToGetDriver() +93
   MySql.Data.MySqlClient.MySqlPool.GetConnection() +65
   MySql.Data.MySqlClient.MySqlConnection.Open() +629
   SalesManager.Models.ConnectionClass.QueryExec() in C:\Users\Gabinet\Source\Repos\SalesManager\SalesManager\SalesManager\Models\Data\ConnectionClass.cs:39
   SalesManager.Models.ProductDownload.GetStorageQuantity(Int32 id) in C:\Users\Gabinet\Source\Repos\SalesManager\SalesManager\SalesManager\Models\ProductDownload.cs:58
   SalesManager.Controllers.SalesController.Index(String sortOrder, String df, String dt) in C:\Users\Gabinet\Source\Repos\SalesManager\SalesManager\SalesManager\Controllers\SalesController.cs:41
   lambda_method(Closure , ControllerBase , Object[] ) +194
   System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +19
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +169
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +27
   System.Web.Mvc.Async.AsyncControllerActionInvoker.<BeginInvokeSynchronousActionMethod>b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState) +24
   System.Web.Mvc.Async.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult) +31
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +50
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +33
   System.Web.Mvc.Async.AsyncInvocationWithFilters.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3d() +50
   System.Web.Mvc.Async.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() +228
   System.Web.Mvc.Async.<>c__DisplayClass33.<BeginInvokeActionMethodWithFilters>b__32(IAsyncResult asyncResult) +15
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +15
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +50
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +35
   System.Web.Mvc.Async.<>c__DisplayClass2b.<BeginInvokeAction>b__1c() +26
   System.Web.Mvc.Async.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult) +100
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult) +15
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +50
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +29
   System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState) +15
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +29
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +50
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +36
   System.Web.Mvc.Controller.<BeginExecute>b__15(IAsyncResult asyncResult, Controller controller) +14
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +22
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +50
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +27
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +12
   System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState) +21
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +29
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.End() +50
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +29
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +11
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +577
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +157

Azure App Insights仅提供超时：

Event code: 3005

Event message: An unhandled exception has occurred.

Event time: 22/12/2017 14:40:56

Event time (UTC): 22/12/2017 14:40:56

Event ID: 503190c80af54cdb87140fe1f808de22

Event sequence: 16

Event occurrence: 5

Event detail code: 0



Application information:

    Application domain: /LM/W3SVC/41351921/ROOT-1-131584264107173868

    Trust level: Full

    Application Virtual Path: /

    Application Path: D:\home\site\wwwroot\

    Machine name: RD00155D58C141



Process information:

    Process ID: 10784

    Process name: w3wp.exe

    Account name: IIS APPPOOL\xxxx



Exception information:

    Exception type: MySqlException

    Exception message: Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding.
   at MySql.Data.Common.StreamCreator.GetTcpStream(MySqlConnectionStringBuilder settings)
   at MySql.Data.Common.StreamCreator.GetStream(MySqlConnectionStringBuilder settings)
   at MySql.Data.MySqlClient.NativeDriver.Open()





Request information:

    Request URL: http://xxxxx.azurewebsites.net/

    Request path: /

    User host address: xx.xxx.xxx.xx

    User: xxxxx

    Is authenticated: True

    Authentication Type: ApplicationCookie

    Thread account name: IIS APPPOOL\xxxx



Thread information:

    Thread ID: 35

    Thread account name: IIS APPPOOL\xxxx

    Is impersonating: False

    Stack trace:    at MySql.Data.Common.StreamCreator.GetTcpStream(MySqlConnectionStringBuilder settings)
   at MySql.Data.Common.StreamCreator.GetStream(MySqlConnectionStringBuilder settings)
   at MySql.Data.MySqlClient.NativeDriver.Open()

我无法在本地计算机上触发此错误。我可以从Azure ping我的MySql数据库。证书是可以的 - 它在我的本地计算机上运行良好。

连接类：

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Web;
using MySql.Data.MySqlClient;

namespace SalesManager.Models
{
    public class ConnectionClass : IDisposable
    {
        private MySqlConnection _con;
        private MySqlCommand _cmd;
        private MySqlDataAdapter _da;
        private DataTable _dt;

        private string _constr =
            "Server=mysqldb.com; Database=databaseName; Uid=database_user; Pwd=database_pass; Default Command Timeout=300000; ";

        public ConnectionClass()
        {
            _con = new MySqlConnection(_constr);
        }

        public void MySqlQuery(string sqlquery)
        {
            _cmd = new MySqlCommand(sqlquery, _con);
        }

        public void MySqlQueryWithParam(string sqlquery, string paramName, string paramValue)
        {
            _cmd = new MySqlCommand(sqlquery, _con);
            _cmd.Parameters.AddWithValue(paramName, paramValue);
        }

        public DataTable QueryExec()
        {
            _con.Open();
            _da = new MySqlDataAdapter(_cmd);
            _dt = new DataTable();
            _da.Fill(_dt);
            _con.Dispose();
            return _dt;
        }

        public void NonQueryExec()
        {
            _con.Open();
            _cmd.ExecuteNonQuery();
            _con.Dispose();
        }

        public void Dispose()
        {
            _con.Close();
            _con.Dispose();
        }
    }
}

失败的方法：

public static int GetStorageQuantity(int id)
{
    if (id != 9999)
    {
        connection = new ConnectionClass();
        string sql = "select quantity from ps_stock_available where id_product = @pId";
            connection.MySqlQueryWithParam(sql, "@pId", id.ToString());
            var dr = connection.QueryExec().Rows[0];
            var quantity = Convert.ToInt32(dr["quantity"].ToString());
            return quantity;
    }
    return 0;
}

我的猜测是我错过了一些我不熟悉的连接池相关内容。

任何想法可能是什么原因？还有什么可以检查？

非常感谢您的帮助！

Answer 1

在这些情况下，总是值得开始使用你的一次性用品......

using (var connection = new ConnectionClass()) {
    //...
}

您可能正在进行太多连接，只有在GC调用dispose方法时才会关闭这些连接。 using语句将提前关闭连接，这可能会解决问题。

这个问题也可能是由其他因素引起的，但我发现故意关闭连接是许多类似问题的解决方案。

超时已过期 - ＆gt;无法连接到任何指定的MySQL主机

1 个答案: