INFO: Do Not Store STA Objects in Session or Application (243543)


The information in this article applies to:

  • Microsoft Active Server Pages, when used with:
    • Microsoft Internet Information Server 3.0
    • Microsoft Internet Information Server 4.0
This article was previously published under Q243543

SUMMARY

Do not store Single-Threaded Apartment (STA) COM components in an Active Server Pages (ASP) Session or Application.

MORE INFORMATION

Storing objects that are marked as STAs, such as components produced by Visual Basic (ActiveX DLLs), limit scalability and can negatively impact performance. Storing STAs in Session scope causes thread affinity and defeats the purpose of a thread pool. When an STA component is stored in Session scope, all subsequent ASP requests from the same user (session) must be executed by the thread that created the component.

In general, stateless page-scoped components perform best. Page-scoped components are COM objects that you create and destroy within the same ASP page. If you need to pass state information from page to page, the following article demonstrates possible techniques that do not use Session:

175167 HOWTO: Persist Values Without Session

REFERENCES

For additional information, click the article numbers below to view the articles in the Microsoft Knowledge Base:

175167 HOWTO: Persist Values Without Session

243548 INFO: Design Guidelines for VB Components Under ASP

Modification Type:MajorLast Reviewed:9/17/2003
Keywords:kbASPObj kbinfo kbScalability kbThread KB243543
©2003 Microsoft Corporation. All rights reserved.