FIX: COM Servers May Stop Responding Under Heavy Load in MTS and Windows 2000

This article was previously published under Q279139
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A Visual FoxPro Component Object Model (COM) server may stop responding under a heavy load when it is run using Microsoft Transaction Server (MTS) under Windows 2000.
Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article. This bug was corrected in the latest service pack for Visual Studio 6.0.

For additional information about Visual Studio service packs, click the following article numbers to view the articles in the Microsoft Knowledge Base:
194022 INFO: Visual Studio 6.0 Service Packs, What, Where, Why

194295 HOWTO: Tell That a Visual Studio Service Pack Is Installed
To download the latest Visual Studio service pack, visit the following Microsoft Web site:

Steps to Reproduce Behavior

  1. Create an Active Server Pages (.asp) page named Mtstest.asp that contains the following code:
    <HTML><BODY><%   lnsecs = Request.QueryString("delay")   set ox = Server.CreateObject("myserver.myclass")   response.write ox.cnt()%></BODY></HTML>					
  2. Place the .asp page in the Wwwroot folder on a Windows 2000 Web server.
  3. On drive C, create a folder called MTSTest.
  4. Start Visual FoxPro.
  5. To create a table to use, run the following code:
       CREATE TABLE C:\MTSTest\Counter FREE (count i)   INSERT INTO counter VALUES (0)   USE 					
  6. Create a project called MyServer, and add the following code to the main program:
    DEFINE CLASS myclass AS form OLEPUBLIC   Datasession=2	&& private datasession   oScriptingContext=0   PROCEDURE Init      SET EXCLUSIVE OFF      USE C:\MTSTest\Counter shared   ENDPROC	   PROCEDURE xOnStartPage(p1)   ENDPROC   PROCEDURE MyDoCmd(cCmd)      &cCmd	&& Just execute parameter as if it were a Fox command.   ENDPROC   FUNCTION MyEval(cExpr)      RETURN &cExpr	&& Evaluate parameter as if it were a Fox expression.   ENDFUNC   PROCEDURE cnt(p1)      LOCAL cStr      REPLACE Counter.count WITH Counter.count+1      cStr = _VFP.fullname+"<br>"      cStr = cStr + 'thread id = '+TRANS(_VFP.threadid) + "<br>"      cStr = cStr + 'Proc id = '+TRANS(_VFP.processid)+ "<br>"      cStr = cStr + '<font size=5 color = red>Count = TRANS(Counter.count)+'</font><br>'      RETURN  cStr   ENDPROCENDDEFINE					
  7. Build the COM server.
  8. Create a package for the COM server in MTS on the Web server. (For more information, see the "References" section.)
  9. Hit Mtstest.asp with multiple threads using the Microsoft Web Application Stress Tool. (For more information, see the "References" section.)
  10. Look at the Web Application Stress Tool report. Failures may be listed in the report as well as in the Windows Event Log.
For additional information, click the article numbers below to view the articles in the Microsoft Knowledge Base:
231282 INFO: Stress Tools to Test Your Web Server
223406 HOWTO: Create an Empty MTS Package to Add Components for ASP
(c) Microsoft Corporation 2000, All Rights Reserved. Contributions by Mark Barnard, Microsoft Corporation.


Article ID: 279139 - Last Review: 02/28/2014 04:22:50 - Revision: 3.3

Microsoft Visual FoxPro 6.0 Professional Edition

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