Vb.net Asp.net应用程序突然停止响应请求

您好，我是.net编程和IIS web部署配置的新手

目前，我有一个asp.net应用程序，它在IIS上使用Framework 4.5运行。在服务器上部署应用程序的第一个月，它运行得很好，也很顺利。然而，最近该应用程序出现了登录页面实际加载的问题，但是当用户输入他们的凭据时，页面加载计时器将显示并且消失，从而使用户陷入困境，无法登录

此外，服务器还经历了如下所述的安全程序：

Windows强化（使用Windows Server 2012）

SQL Server强化（SQL Server 2012）和端口更改为8001

此外，应用程序的体系结构是：

应用程序部署在AMLWEB服务器中

SQL Server数据库位于AMLDB服务器中

因此，连接实际上是通过服务器进行的，登录身份验证实际上是针对Active Directory进行的

随附的屏幕截图：

在事件查看器上选中时，会看到以下警告，提示可能是问题的原因：

Event code: 3005 
Event message: An unhandled exception has occurred. 
Event time: 1/18/2015 5:27:15 PM 
Event time (UTC): 1/18/2015 9:27:15 AM 
Event ID: 2ac169fff7284e86b7b0844e5d9ccab1 
Event sequence: 4 
Event occurrence: 1 
Event detail code: 0 

Application information: 
    Application domain: /LM/W3SVC/1/ROOT/AML-1-130660468323976167 
    Trust level: Full 
    Application Virtual Path: /AML
    Application Path: D:\AML\ 
    Machine name: AMLWEB 

Process information: 
    Process ID: 6756 
    Process name: w3wp.exe 
    Account name: IIS APPPOOL\.NET v4.5 

Exception information: 
    Exception type: InvalidOperationException 
    Exception message: The ConnectionString property has not been initialized.
   at System.Data.SqlClient.SqlConnection.PermissionDemand()
   at System.Data.SqlClient.SqlConnectionFactory.PermissionDemand(DbConnection outerConnection)
   at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry) at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
   at System.Data.SqlClient.SqlConnection.Open()
   at DBManager.DBManager.OpenConnection(String DBStrConn, Int16 DBType) in C:\Users\TESS-HP003\Desktop\AML\ES_Library\DBManager\DBManager.vb:line 50
   at DBManager.DBManager.ExecuteSQLQuery_ReturnDS(String& ReturnErrorMsg, String SqlString, String DBConnString, Int16 DBType) in C:\Users\TESS-HP003\Desktop\AML\ES_Library\DBManager\DBManager.vb:line 190
   at SQLAdminQueryManager.AdminQueryManager.AdminQueryManager_Staff_Login.Staff_Login_Retreive(cor_staff AppEntity, String DbSQLConnString, String DbType, String& ReturnErrorMsg, Object& ReturnObjDataset, String AccessType) in C:\Users\TESS-HP003\Desktop\AML\ES_Library\SQLAdminQueryManager\AdminQueryManager.vb:line 65
   at Login_page_LDAP_Code.LoginButton_Click(Object sender, EventArgs e)
   at System.Web.UI.WebControls.Button.OnClick(EventArgs e)
   at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)
   at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
   at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
   at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)



Request information: 
    Request URL: https://amlweb/AML/Login_page.aspx 
    Request path: /AML/Login_page.aspx 
    User host address: 10.1.67.61 
    User:  
    Is authenticated: False 
    Authentication Type:  
    Thread account name: IIS APPPOOL\.NET v4.5 

Thread information: 
    Thread ID: 10 
    Thread account name: IIS APPPOOL\.NET v4.5 
    Is impersonating: False 
    Stack trace:    at System.Data.SqlClient.SqlConnection.PermissionDemand()
   at System.Data.SqlClient.SqlConnectionFactory.PermissionDemand(DbConnection outerConnection)
   at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
   at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
   at System.Data.SqlClient.SqlConnection.Open()
   at DBManager.DBManager.OpenConnection(String DBStrConn, Int16 DBType) in C:\Users\TESS-HP003\Desktop\AML\ES_Library\DBManager\DBManager.vb:line 50
   at DBManager.DBManager.ExecuteSQLQuery_ReturnDS(String& ReturnErrorMsg, String SqlString, String DBConnString, Int16 DBType) in C:\Users\TESS-HP003\Desktop\AML\ES_Library\DBManager\DBManager.vb:line 190
   at SQLAdminQueryManager.AdminQueryManager.AdminQueryManager_Staff_Login.Staff_Login_Retreive(cor_staff AppEntity, String DbSQLConnString, String DbType, String& ReturnErrorMsg, Object& ReturnObjDataset, String AccessType) in C:\Users\TESS-HP003\Desktop\AML\ES_Library\SQLAdminQueryManager\AdminQueryManager.vb:line 65
   at Login_page_LDAP_Code.LoginButton_Click(Object sender, EventArgs e)
   at System.Web.UI.WebControls.Button.OnClick(EventArgs e)
   at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)
   at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
   at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
   at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)


Custom event details: 

但是，连接字符串确实已正确设置，如下所示：

Web.config

<connectionStrings>
    <add name="AMLDBConnectionString" connectionString="Data Source=AMLDB01, 8001;Initial Catalog=AML_DB;integrated security=true; uid=sa; pwd=p@ssw0rd"/>
</connectionStrings>

实际执行以连接到DB的线路：

blnReturnValue = objSqlQuery.Staff_Login_Retreive(objBE, GlobalSQLConnString, GlobalDBType, strErrorMsgReturn, returnDS, "S")

调用的方法：

Public Function Staff_Login_Retreive(ByVal AppEntity As BusinessEntities.cor_staff, _
                                             ByVal DbSQLConnString As String, ByVal DbType As String, _
                                             ByRef ReturnErrorMsg As String, ByRef ReturnObjDataset As Object, _
                                             Optional ByVal AccessType As String = "S") As Boolean
            With AppEntity
                SQlQuery = "SELECT * "
                SQlQuery += " FROM cor_staff "
                SQlQuery += " WHERE cor_staff.cor_userid =N'" & AppEntity.cor_userid & "'"
            End With
            '
            If AccessType.ToUpper = "R" Then
                ReturnObjDataset = ExecuteSQLQuery_ReturnIDR(ReturnErrorMsg, SQlQuery, DbSQLConnString, DbType)
            Else
                ReturnObjDataset = ExecuteSQLQuery_ReturnDS(ReturnErrorMsg, SQlQuery, DbSQLConnString, DbType)
            End If
            '
            If ReturnErrorMsg.Trim.Length = 0 Then
                Return True
            Else
                Return False
            End If
            '
        End Function

已编辑

由于上述代码实际上会在这一行中运行并被调用：

ReturnObjDataset = ExecuteSQLQuery_ReturnDS(ReturnErrorMsg, SQlQuery, DbSQLConnString, DbType)

连接将仅在此处打开：

Public Function ExecuteSQLQuery_ReturnDS(ByRef ReturnErrorMsg As String, ByVal SqlString As String, ByVal DBConnString As String, ByVal DBType As Int16) As DataSet
        ReturnErrorMsg = ""
        Dim DS As New DataSet
        '
        If DBType = 1 Then
            Try
                OpenConnection(DBConnString, DBType)
                Dim sqlCmd As New SqlCommand(SqlString, sqlConn)
                sqlCmd.CommandTimeout = 0
                Dim sqlDaAdp As New SqlDataAdapter(sqlCmd)
                sqlDaAdp.Fill(DS)
                sqlCmd = Nothing
                sqlDaAdp = Nothing
                CloseConnection(DBType)
                Return DS
            Catch ex As SqlException
                If ex.Number = 18456 Or ex.Number = 4060 Then
                    ReturnErrorMsg = "Database Connection Error >> Error No : " & ex.Number
                Else
                    ReturnErrorMsg = "SQL Statement Error >> Error No : " & ex.Number
                End If
                CloseConnection(DBType)
                Return Nothing
            End Try
        ElseIf DBType = 3 Then
            Try
                OpenConnection(DBConnString, DBType)
                Dim oledbCmd As New OleDbCommand(SqlString, oleDbconn)
                Dim oledbDaAdp As New OleDbDataAdapter(oledbCmd)
                oledbDaAdp.Fill(DS)
                oledbDaAdp = Nothing
                oledbDaAdp = Nothing
                CloseConnection(DBType)
                Return DS
            Catch ex As OleDbException
                If ex.ErrorCode = -2147217887 Then
                    ReturnErrorMsg = "Database Connection Error >> Error Code : " & ex.ErrorCode
                Else
                    ReturnErrorMsg = "SQL Statement Error >> Error Code : " & ex.ErrorCode
                End If
                CloseConnection(DBType)
                Return Nothing
            End Try
        End If
        '
        Return Nothing
        '
    End Function

开放式连接方法：

Public Sub OpenConnection(ByVal DBStrConn As String, ByVal DBType As Int16)
        Try
            If DBType = 1 Then
                sqlConn = New SqlConnection(DBStrConn)
                If sqlConn.State = ConnectionState.Closed Then
                    sqlConn.Open()
                Else
                    sqlConn.Close()
                    sqlConn.Open()
                End If
            ElseIf DBType = 3 Then
                oleDbconn = New OleDbConnection(DBStrConn)
                If oleDbconn.State = ConnectionState.Closed Then
                    oleDbconn.Open()
                Else
                    oleDbconn.Close()
                    oleDbconn.Open()
                End If
            End If
            '
        Catch ex As Exception
            Throw
        End Try

    End Sub

编辑部分结束

有人知道为什么会出现这种例外吗

到目前为止，我已经做了以下工作来实际调试此问题：

重新启动IIS

重新启动应用程序池

回收应用程序池（特别是每12小时、上午8点和下午8点）

重新启动SQL Server服务

上述措施都不起作用。但是，当我实际尝试从特定楼层（即安全团队楼层）访问应用程序时，应用程序实际上开始正常运行，其他人也可以实际访问应用程序

请帮帮我，我对这个问题简直是疯了

它是否与我的部署方法、iis配置或编程有关，我愿意听取建议

---

感谢您抽出时间。

您是否明确打开了连接？先生，这个异常看起来您没有担心，但是您的意思是如何明确地打开连接？我已经相应地编辑了这篇文章，添加了连接被打开的代码。谢谢。请尝试以下操作以获取连接字符串。。。ConfigurationManager.ConnectionString（“AMLDBConnectionString”）.ConnectionStringSir，它是否与我包含的上述代码不同？。。GlobalSQLConnString=ConfigurationManager.ConnectionString（“AMLDBConnectionString”）.ToString。。对不起，我是个新手。您的连接字符串表示受信任（integrated security=true）和SQL（uid=sa）身份验证。你用哪一种？您只能使用一个。2.您的错误消息指向桌面上的VB文件。这就是你部署web应用的地方吗？简言之，服务器加固可能已打开防火墙，这反过来意味着您无法连接。远程连接到web服务器，并确认（使用UDL或ODBC）是否可以连接到SQL server

Public Sub OpenConnection(ByVal DBStrConn As String, ByVal DBType As Int16)
        Try
            If DBType = 1 Then
                sqlConn = New SqlConnection(DBStrConn)
                If sqlConn.State = ConnectionState.Closed Then
                    sqlConn.Open()
                Else
                    sqlConn.Close()
                    sqlConn.Open()
                End If
            ElseIf DBType = 3 Then
                oleDbconn = New OleDbConnection(DBStrConn)
                If oleDbconn.State = ConnectionState.Closed Then
                    oleDbconn.Open()
                Else
                    oleDbconn.Close()
                    oleDbconn.Open()
                End If
            End If
            '
        Catch ex As Exception
            Throw
        End Try

    End Sub