ASP.net用户数据在访问对象的用户之间进行交叉

Question

这有点奇怪.我正在寻找关于如何提出正确问题的想法,因为我是一个真正的解决方案.

我有一个网站,我们的流量大幅增加.现在突然间我们得到左右sql参数错误.几个星期前我们切换到一个新的SQL服务器,一切都很好,但增加的流量似乎打破了我们.

我有一个数据访问类,每个用户尝试登录时调用.在最终更新用户上次登录日期并将其转发到管理部分之前,它会运行多个任务.

我从跟踪日志中看到的内容表明,当我登录时,前几个任务正在使用我的数据(比方说user = birk pass = word).但是在某些时候,访问者类开始从试图登录的其他人发送数据(比方说user = abcxyz)

当我们完成它时,我们对服务器的每个连接都会关闭.当我完成它们时,我将所有的访问器对象归零.但不知何故,来自不同会话的不同用户数据正在进入对象的其他人群实例.

我没有使用session/application/cache/viewstate来存储对象,所以我真的没看到他们如何编辑彼此...它真的很奇怪,我不知道如何研究这个问题.

这大致是访问者类......我修剪了一些不依赖于问题的部分

Imports Microsoft.VisualBasic
Imports System.Data
Imports System.Data.SqlClient
Imports System.Text.RegularExpressions
Imports System.Text
Imports System.IO

Namespace ABC
    Public Class DataAccess
        Public Class SQL
            Dim objConnection As SqlConnection
            Dim objAdapter As SqlDataAdapter
            Dim objDataset As DataSet
            Dim objTable As DataTable
            Dim strSQL As String
            Dim strCommandType As String
            Shared sqlparams As List(Of param)
            Public params As New Parameters
            Shadows Application As HttpApplicationState = HttpContext.Current.Application
            Shadows Server As HttpServerUtility = HttpContext.Current.Server
            Shadows Response As HttpResponse = HttpContext.Current.Response
            Shadows Session As HttpSessionState = HttpContext.Current.Session

            Public Sub New()
                Connection()
            End Sub

            Public Sub New(ByVal startingSql As String)
                Connection()
                sql = startingSql
            End Sub

            Private Sub Connection()
                sqlparams = New List(Of param)
                objConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("sqlServerProd").ConnectionString)
            End Sub

            Public Function DataNQ(ByVal type As CommandType, Optional ByVal query As String = "") As Boolean
                If query <> "" Then
                    sql = query
                End If
                Dim objCommand As SqlCommand
                Try
                    objConnection.Open()
                Catch ex As Exception
                    objConnection.Close()
                    objConnection.Open()
                End Try
                objCommand = New SqlCommand(sql, objConnection)
                objCommand.CommandType = type
                Dim cmd As New SqlCommand
                HttpContext.Current.Trace.Warn(sql)
                'HttpContext.Current.Trace.Write("Adding " & sqlparams.Count & " parameters")
                HttpContext.Current.Trace.Warn(params.writeParams)
                If sqlparams.Count > 0 Then
                    For Each p As param In sqlparams
                        Dim sparam As SqlParameter = p.makeParam
                        HttpContext.Current.Trace.Write(sparam.DbType.ToString, sparam.ParameterName & "=" & sparam.Value)
                        objCommand.Parameters.Add(p.makeParam)
                    Next
                    sqlparams = New List(Of param)
                End If
                HttpContext.Current.Trace.Warn("Successfully added " & objCommand.Parameters.Count & " parameters")
                HttpContext.Current.Trace.Warn(params.writeParams)

                '-- Create a SqlParameter object to hold the output parameter value
                Dim paramRetVal As New SqlParameter("@RETURN_VALUE", SqlDbType.Int)
                '-- Must set .Direction as ReturnValue
                paramRetVal.Direction = ParameterDirection.ReturnValue
                '-- Finally, add the parameter to the Command's Parameters collection
                objCommand.Parameters.Add(paramRetVal)
                '-- Call the sproc...
                Dim reader As SqlDataReader = objCommand.ExecuteReader()
                'Now you can grab the output parameter's value...

                Dim intRetVal As Integer = Convert.ToInt32(paramRetVal.Value)
                If intRetVal = 0 Then
                    objConnection.Close()
                    objCommand = Nothing
                    reader = Nothing
                    Return True
                Else
                    objConnection.Close()
                    objCommand = Nothing
                    reader = Nothing
                    Return False
                End If
                objConnection.Close()

            End Function

            Public Sub freeResources()
                sqlparams = Nothing
                params = Nothing
                objConnection = Nothing
                objAdapter = Nothing
                objDataset = Nothing
                objTable = Nothing
                strSQL = Nothing
                strCommandType = Nothing
            End Sub

        Public Sub add(ByVal parameterName As String, ByVal dbType As System.Data.SqlDbType, ByVal size As Integer, ByRef value As Object)
            HttpContext.Current.Trace.Write("adding param name/type/size/value", parameterName & " " & value)
            Dim p As param
            p = New param(parameterName, dbType, size, value)
            p.Value = value
            sqlparams.Add(p)
        End Sub

            Private Class param
                Public name As String = Nothing
                Public size As Integer = Nothing
                Public type As System.Data.SqlDbType = Nothing
                Public value As Object = Nothing
                Public Function makeParam() As SqlParameter
                    HttpContext.Current.Trace.Warn("before make param name=" & name & " type=" & type.ToString & " value=" & value)
                    Dim p As New SqlParameter(name, type)
                    If size <> Nothing Then
                        p.Size = size
                    End If
                    p.Value = value
                    HttpContext.Current.Trace.Warn("after make param name=" & p.ParameterName & " type=" & p.DbType.ToString)
                    Return p
                End Function

        Public Sub New(ByVal pname As String, ByRef ptype As System.Data.SqlDbType, ByRef val As Object)
            'HttpContext.Current.Trace.Write("new param object name/type/value name=" & pname & " type=" & ptype.ToString)
            name = pname
            type = ptype
            value = val
            'HttpContext.Current.Trace.Warn("added param name=" & name & " type=" & type.ToString)
                End Sub
            End Class


        End Class
    End Class

任何想法或想法都会很棒.谢谢

Answer 1

你sqlparams As List(Of param)宣布为Shared.这意味着它只在内存中创建了一个实例.

从每一个实例化的页面,它的每一个参考使用同一个实例的sqlparams.

这意味着您的页面的一个实例已使用一些参数填充它,并且页面的某些其他实例启动,调用您的Connection()方法并清除它.当处理器切换回第一页的线程时,sqlparams现在是新的,(或者更糟糕的是,Nothing如果另一个线程只调用你的freeResources()方法).

使用此代码,您的页面本质上是非线程安全的.Shared用实例变量替换所有变量,它应该解决问题.