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 uses this .dll file and its default timeout.

RESOLUTION

This limitation is fixed in RDS 2.0 that released with Microsoft Data Access Components (MDAC) 2.0. These files can be downloaded from the following Web address:

http://www.microsoft.com/data/mdac2.htm

The RDS.Dataspace and RDS.Datacontrol in this release have a new property Called InternetTimeout, which takes the following range of values:

• 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.

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("prjInternetTimeOut.clsDelay",
       "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:

ARTICLE-ID: Q166277 TITLE : HOWTO: Create a VB Component that Returns a Recordset in RDS

ARTICLE-ID: Q181092 TITLE : FAQ: Remote Data Service (RDS) Frequently Asked Questions

For more information, please see the following World Wide Web URL:

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

For additional information, please see the following public newsgroup:

   microsoft.public.ado.rds 

Additional query words: MDAC kbRDS150bug kbRDS200fix kbRDS kbVBp

Keywords          : 
Version           : WINDOWS:1.5
Platform          : WINDOWS 
Issue type        : kbbug 

Last Reviewed: June 11, 1999