Microsoft KB Archive/305678

= PRB: Object Instantiation Fails, Web Page Times Out =

Article ID: 305678

Article Last Modified on 1/23/2002

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APPLIES TO


 * Microsoft Application Center 2000 Standard Edition

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This article was previously published under Q305678



SYMPTOMS
Object instantiation fails or the Web pages times out on a Web server that uses Microsoft Application Center 2000.



CAUSE
These issues are caused when you place a firewall between a Web server that uses Application Center 2000 Component Load Balancing (CLB) and the application servers that instantiate the objects being load balanced.

When you use CLB to load balance calls from Microsoft Internet Information Server (IIS) to another Component Object Model+ (COM+) server, CLB always tries to marshal the IIS intrinsic objects. This requires a distributed version of Component Object Model (DCOM) session from the application server back to the Web server. If the firewall only allows DCOM connections in one direction (from the Web server to the application server) then the object instantiation fails.



RESOLUTION
To resolve this issue, allow DCOM connections in both directions through the firewall.

As an alternative, you can implement local components on the Web servers. To do this, set the IISIntrinsics property set to 0, and then have the local components call the load balanced components.

For additional information about setting the IISIntrinsics property, click the article number below to view the article in the Microsoft Knowledge Base:

287422 PRB: IISIntrinsics Flow by Default When You Call COM+ Components from IIS 5.0 Applications



STATUS
This behavior is by design.



MORE INFORMATION
Whenever IIS instantiates a COM component, IIS always tries to marshal the IIS intrinsic objects such as the Application and Response objects. This causes the instantiated object to create connections back to the IIS server by which the object is received. This issue can also occur over a standard DCOM connection from IIS to an application server. Regular COM+ applications can also marshal the IIS intrinsic objects to any objects they instantiate. To control this issue modify the IISIntrinsics property.

Additional query words: setting the IISIntrinsics property firewall port session open hang ASP

Keywords: kbprb KB305678

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