EF6：在 For Next 循环中获取更新超时
EF6: Getting Timout on Update while in For Next Loop
我有一个 table，其中包含需要通过 API 发送到服务的数据。我创建了一个启动计时器的 Windows 服务。一旦计时器结束，它就会运行 SUB ProcessRequests()。在这里，我使用 EF 获取任何新请求行。然后我有一个 For Next 循环，它从连续的各个文件中组成一个 json 字符串并触发一个 api 调用。所有这些工作到此为止。
我也从 api 得到了回复，我需要用这些数据更新相应的行，并更新状态字段和 raisedOn 字段。不幸的是 dc.SaveChanges 最终导致异常，异常消息是超时或连接问题。获取新行的初始调用没有连接问题，也没有超时。我在想我可能有行锁问题或其他问题。任何帮助表示赞赏。
我的代码是：
Sub ProcessRequests()
' Define the various objects we're going to use
Dim newServiceNowEvent As ServiceNowEvent = Nothing
Dim de As New AutoTicketDBEntities
Try
' Open a connnection to the database and get any Request that are not COMPLETED
Dim EventQuery = (From r In de.Ticket_Requests
Order By r.Requested
Where r.snEventRaised <> "Completed"
Select r.ID, r.Prefix, r.UniqueID, r.TicketText, r.UserUniqueID, r.UserSysID, r.snEventExceptionText)
' Iterate through any new records
For Each EventRequest In EventQuery
Try
' Create a new instance of the OpsViewEventParser class (EventDetails) and parse the content of the TicketText field
Dim EventDetails As New OpsViewEventParser(EventRequest.TicketText)
' If there has been a parsing error, the Summary property of TicketDetails will contain "Parse Error",
' so we'll throw an exception. The Message property will contain details of the exception encountered
If EventDetails.Summary = "Parse Error" Then
Console.WriteLine("There was a Parsing Error")
Throw New Exception(EventDetails.Summary & " - " & EventDetails.Message)
End If
'Parsing was successful
' Create a new instance of the ServiceNowEvent class and populate its properties from EventDetails
newServiceNowEvent = New ServiceNowEvent
With newServiceNowEvent
.source = EventDetails.Source
.event_class = EventDetails.EventType
.node = EventDetails.Host
.metric_name = EventDetails.SubSource
.type = EventDetails.SubSource
.message_key = ""
.severity = EventDetails.Priority
.description = EventDetails.SmartDescription
.additional_info = EventDetails.CreateOpsViewJson
.time_of_event = EventDetails.EventTime
' Raise the ServiceNow Event
.RaiseServiceNowEvent()
End With
If newServiceNowEvent.SNReturnStatus.StartsWith("Error") Then
Throw New Exception(newServiceNowEvent.SNReturnMessage)
End If
' No Errors so Update the Ticket_Requests table with the snEventStatus (Completed) and a timestamp
' We also save the json we posted to the SN API
Dim dc As New AutoTicketDBEntities
Try
Dim EventToUpdate = (From i In dc.Ticket_Requests
Where i.ID = EventRequest.ID
Select i).FirstOrDefault()
If EventToUpdate IsNot Nothing Then
EventToUpdate.snEventRaised = "COMPLETED"
EventToUpdate.snEventCreated = Now()
EventToUpdate.snEventJSONString = newServiceNowEvent.GeneratedJSONstring.Replace("'", "''")
EventToUpdate.snEventSmartTeam = EventDetails.Team.ToUpper
EventToUpdate.snEventStatus = "EventCreated"
dc.SaveChanges() '####### THIS IS WHERE THE CODE TIMES-OUT ##########
End If
Catch ex As Exception
' Write details of the exception to the Application Log
EventLog.WriteEntry("AutoEvent ServiceNow Service", "The ServiceNow Event Service failed. The Exception reported was " & ex.Message, EventLogEntryType.Error)
Finally
dc.Dispose()
End Try
Catch ex1 As Exception
Dim dc As New AutoTicketDBEntities
Try
Dim EventToUpdate = dc.Ticket_Requests.SingleOrDefault(Function(i) i.ID = EventRequest.ID)
If EventToUpdate IsNot Nothing Then
EventToUpdate.snEventRaised = "PROCESSING"
EventToUpdate.snEventExceptionText = ex1.Message
EventToUpdate.snEventJSONString = newServiceNowEvent.GeneratedJSONstring.Replace("'", "''")
EventToUpdate.snEventFailCount += 1
de.SaveChanges()
End If
Catch ex As Exception
' Write details of the exception to the Application Log
EventLog.WriteEntry("AutoEvent ServiceNow Service", "The ServiceNow Event Service failed. The Exception reported was " & ex.Message, EventLogEntryType.Error)
Finally
dc.Dispose()
End Try
EventLog.WriteEvent("AutoEvent ServiceNow Service", "The ServiceNow Auto Event Service encountered an error raising an incident but failed to update the database with details of the error. The Exception whilst attempting to raise the incident was " & ex1.Message, EventLogEntryType.Error)
End Try
Next
Catch ex As Exception
' Write details of the exception to the Application Log
EventLog.WriteEntry("AutoEvent ServiceNow Service", "The ServiceNow Event Service failed. The Exception reported was " & ex.Message, EventLogEntryType.Error)
Finally
de.Dispose()
End Try
End Sub ' END ProcessRequest
通过将第一个查询设为列表并处理连接然后循环遍历列表来解决问题。主要变化是
Dim EventQuery As List(Of Ticket_Requests)
Try
' Open a connnection to the database and get any Request that are not COMPLETED
EventQuery = (From r In de.Ticket_Requests
Order By r.Requested
Where r.snEventRaised <> "Completed"
Select r).ToList()
Console.WriteLine("We have " & EventQuery.Count & " events to process.")
' Iterate through any new records
Catch ex As Exception
' Write details of the exception to the Application Log
Console.WriteLine("AutoEvent ServiceNow Service - The ServiceNow Event Service failed. The Exception reported was " & ex.Message)
Console.WriteLine(ex.InnerException.Message)
Finally
de.Dispose()
End Try
'Then continue with the Loop code....
希望这对其他人有帮助。
我有一个 table，其中包含需要通过 API 发送到服务的数据。我创建了一个启动计时器的 Windows 服务。一旦计时器结束，它就会运行 SUB ProcessRequests()。在这里，我使用 EF 获取任何新请求行。然后我有一个 For Next 循环，它从连续的各个文件中组成一个 json 字符串并触发一个 api 调用。所有这些工作到此为止。
我也从 api 得到了回复，我需要用这些数据更新相应的行，并更新状态字段和 raisedOn 字段。不幸的是 dc.SaveChanges 最终导致异常，异常消息是超时或连接问题。获取新行的初始调用没有连接问题，也没有超时。我在想我可能有行锁问题或其他问题。任何帮助表示赞赏。
我的代码是：
Sub ProcessRequests()
' Define the various objects we're going to use
Dim newServiceNowEvent As ServiceNowEvent = Nothing
Dim de As New AutoTicketDBEntities
Try
' Open a connnection to the database and get any Request that are not COMPLETED
Dim EventQuery = (From r In de.Ticket_Requests
Order By r.Requested
Where r.snEventRaised <> "Completed"
Select r.ID, r.Prefix, r.UniqueID, r.TicketText, r.UserUniqueID, r.UserSysID, r.snEventExceptionText)
' Iterate through any new records
For Each EventRequest In EventQuery
Try
' Create a new instance of the OpsViewEventParser class (EventDetails) and parse the content of the TicketText field
Dim EventDetails As New OpsViewEventParser(EventRequest.TicketText)
' If there has been a parsing error, the Summary property of TicketDetails will contain "Parse Error",
' so we'll throw an exception. The Message property will contain details of the exception encountered
If EventDetails.Summary = "Parse Error" Then
Console.WriteLine("There was a Parsing Error")
Throw New Exception(EventDetails.Summary & " - " & EventDetails.Message)
End If
'Parsing was successful
' Create a new instance of the ServiceNowEvent class and populate its properties from EventDetails
newServiceNowEvent = New ServiceNowEvent
With newServiceNowEvent
.source = EventDetails.Source
.event_class = EventDetails.EventType
.node = EventDetails.Host
.metric_name = EventDetails.SubSource
.type = EventDetails.SubSource
.message_key = ""
.severity = EventDetails.Priority
.description = EventDetails.SmartDescription
.additional_info = EventDetails.CreateOpsViewJson
.time_of_event = EventDetails.EventTime
' Raise the ServiceNow Event
.RaiseServiceNowEvent()
End With
If newServiceNowEvent.SNReturnStatus.StartsWith("Error") Then
Throw New Exception(newServiceNowEvent.SNReturnMessage)
End If
' No Errors so Update the Ticket_Requests table with the snEventStatus (Completed) and a timestamp
' We also save the json we posted to the SN API
Dim dc As New AutoTicketDBEntities
Try
Dim EventToUpdate = (From i In dc.Ticket_Requests
Where i.ID = EventRequest.ID
Select i).FirstOrDefault()
If EventToUpdate IsNot Nothing Then
EventToUpdate.snEventRaised = "COMPLETED"
EventToUpdate.snEventCreated = Now()
EventToUpdate.snEventJSONString = newServiceNowEvent.GeneratedJSONstring.Replace("'", "''")
EventToUpdate.snEventSmartTeam = EventDetails.Team.ToUpper
EventToUpdate.snEventStatus = "EventCreated"
dc.SaveChanges() '####### THIS IS WHERE THE CODE TIMES-OUT ##########
End If
Catch ex As Exception
' Write details of the exception to the Application Log
EventLog.WriteEntry("AutoEvent ServiceNow Service", "The ServiceNow Event Service failed. The Exception reported was " & ex.Message, EventLogEntryType.Error)
Finally
dc.Dispose()
End Try
Catch ex1 As Exception
Dim dc As New AutoTicketDBEntities
Try
Dim EventToUpdate = dc.Ticket_Requests.SingleOrDefault(Function(i) i.ID = EventRequest.ID)
If EventToUpdate IsNot Nothing Then
EventToUpdate.snEventRaised = "PROCESSING"
EventToUpdate.snEventExceptionText = ex1.Message
EventToUpdate.snEventJSONString = newServiceNowEvent.GeneratedJSONstring.Replace("'", "''")
EventToUpdate.snEventFailCount += 1
de.SaveChanges()
End If
Catch ex As Exception
' Write details of the exception to the Application Log
EventLog.WriteEntry("AutoEvent ServiceNow Service", "The ServiceNow Event Service failed. The Exception reported was " & ex.Message, EventLogEntryType.Error)
Finally
dc.Dispose()
End Try
EventLog.WriteEvent("AutoEvent ServiceNow Service", "The ServiceNow Auto Event Service encountered an error raising an incident but failed to update the database with details of the error. The Exception whilst attempting to raise the incident was " & ex1.Message, EventLogEntryType.Error)
End Try
Next
Catch ex As Exception
' Write details of the exception to the Application Log
EventLog.WriteEntry("AutoEvent ServiceNow Service", "The ServiceNow Event Service failed. The Exception reported was " & ex.Message, EventLogEntryType.Error)
Finally
de.Dispose()
End Try
End Sub ' END ProcessRequest
通过将第一个查询设为列表并处理连接然后循环遍历列表来解决问题。主要变化是
Dim EventQuery As List(Of Ticket_Requests)
Try
' Open a connnection to the database and get any Request that are not COMPLETED
EventQuery = (From r In de.Ticket_Requests
Order By r.Requested
Where r.snEventRaised <> "Completed"
Select r).ToList()
Console.WriteLine("We have " & EventQuery.Count & " events to process.")
' Iterate through any new records
Catch ex As Exception
' Write details of the exception to the Application Log
Console.WriteLine("AutoEvent ServiceNow Service - The ServiceNow Event Service failed. The Exception reported was " & ex.Message)
Console.WriteLine(ex.InnerException.Message)
Finally
de.Dispose()
End Try
'Then continue with the Loop code....
希望这对其他人有帮助。