FIX: RDS Query Times Out After Five Minutes

• Remote Data Service for ADO version 1.5

SYMPTOMS

Remote Data Service (RDS) version 1.5 times out when trying to run queries longer than five minutes. Clients receive the following error message:

Internet Client Error : Request Timeout.

CAUSE

The Wininet.dll has a default timeout of five minutes. RDS 1.5 used this .dll file and its default timeout.

RESOLUTION

This limitation is fixed in RDS 2.0 and later. You may download the latest version of Microsoft Data Access Components, including RDS, from the following Web address:

http://www.microsoft.com/data/download.htm

• Minimum value of -2,147,483,648 (Times out immediately, any negative times out immediately.)



• Maximum value of 2,147,483,647 (596 hours or 24 days, never times out.)



• Value of 0 (will not timeout.)



• Negative value (will timeout immediately.)

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article.

This bug was corrected in RDS 2.0 and later.

MORE INFORMATION

Steps to Reproduce Behavior

Creating the ActiveX DLL

1. Start a new project in Visual Basic and select "ActiveX DLL". Class1 is created by default.



2. From the Project menu, select Project1 Properties. Change the Project name to RDSTimeOutTestObj and the Project Description to RDS Time Out Test Object. Click OK to close the Project Properties dialog box.



3. Select Class1 in your Project Window and press F4 to view the Properties. Change the Instancing property of Class1 to "5 MultiUse".



4. Paste the following code into the General Declarations section of Class1:




Option Explicit
Const SUCCESS = 999
Public Function WaitForAllotedtime(ByVal WaitTime As Integer) As _
Integer
  Pause (WaitTime) 'Introduce a delay simulating a long running query
  WaitForAllotedtime = SUCCESS
End Function

Sub Pause(ByVal nSecond As Single)
  Dim t0 As Single
  t0 = Timer
  Do While Timer - t0 < nSecond ' This loop introduces the delay of
  Dim dummy As Integer          ' nSecond using the Timer function.
  dummy = DoEvents()
  If Timer < t0 Then
   t0 = t0 - CLng(24) * CLng(60) * CLng(60)
  End If
  Loop
 End Sub 

5. Save the project.



6. From the File menu, click "Make RDSTimeOutTestObj.dll". You are now finished creating your ActiveX .dll project.
   

Creating the Visual Basic Test Client

1. Test the ActiveX .dll project by creating another Visual Basic Standard .exe project as a client.



2. From the File menu, click New Project, and then select Standard .exe project. Form1 is created by default.



3. From the Project menu, select references and add a reference to the Microsoft Remote Data Services 2.0 Library.



4. Place a Command button, named Command1, on Form1.



5. Paste the following code into the General Declarations section of Form1:




Private Sub Command1_Click()
 Dim rs As New RDS.DataSpace
 Dim obj As Object
 Dim i As Integer
 rs.InternetTimeout = 305000   ' This is in milliseconds.
 Set obj = rs.CreateObject("RDSTimeOutTestObj.Class1", _
    "http://<your server name>")
 i = obj.WaitForAllotedTime(301)'301 seconds, cross the 5 min barrier
 MsgBox i   ' Should get 999 indicating success.
End Sub 

Registering the ActiveX .dll to Run on RDS

1. If you are not developing on your IIS server, you need to manually copy over the .dll to the IIS server and manually register it using Regsvr32.exe. Also check to make sure the RDSTimeOutTestObj business object is correctly registered on your IIS/RDS server. To see if the component is correctly registered, look in the registry by running "regedit" from the Run menu. The components are under the HKEY_CLASSES_ROOT key in alphabetical order.



2. Make sure your createable object has launch rights on your server. This can be done by taking the following lines and saving them in a file with a .reg extension and double-clicking the file to merge the information into the registry. You can also do this manually with Regedit.exe:




REGEDIT4
   ;This entry should be on one line
   [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC
    \Parameters\ADCLaunch\RDSTimeOutTestObj.Class1] 

Testing the Application

1. Run the Visual Basic client.



2. Click the Command1 button.



3. You should see a message box that displays 999, which indicates that the long running query has executed successfully without creating the following error:




Internet Client Error : Request Timeout.

4. To check whether the InternetTimeOut setting works you can set the InternetTimeOut value to something less than 301000 millisecond to get the error.

REFERENCES

For additional information, please see the following articles in the Microsoft Knowledge Base:

Q166277 HOWTO: Create a VB Component that Returns a Recordset in RDS

http://www.microsoft.com/data/ado/rds/

   microsoft.public.ado.rds 

Additional query words:

Keywords : kbDatabase kbRDS kbRDS150 kbRDS150bug kbRDS200fix kbVBp kbGrpVBDB kbGrpMDAC kbDSupport kbRDS210SP2
Version : WINDOWS:1.5
Platform : WINDOWS
Issue type : kbbug