LANSA for the Web and performance degradation using Windows 2003 and IIS 6.0

Date: Archived
Product/Release: LANSA for the Web
Abstract: Windows 2003 Server and IIS 6.0
Submitted By: LANSA Technical Support


Windows 2003 Server and IIS 6.0 causes large speed differences between applications using internal IP address and external IP address to serve Web pages. In particular, a significant performance degradation is noticed when using an external IP address.

The problem is not exclusive to LANSA but has affected LANSA due to an architectural change introduced by Microsoft for Windows 2003 and IIS 6.0. We are currently working on a fix to our ISAPI plugin to circumvent this problem.

To understand the exact change, review the following extract from Microsoft article IIS 6.0 is slower than IIS 5.0 when you use the WriteClient API to send data. The change that has affected LANSA's ISAPI plugin (and other vendors) is "To rectify this situation, it is recommended that existing ISAPI applications be changed to use the asynchronous versions of the WriteClient API"


A new version of the ISAPI plugin to workaround this architectural change in Windows 2003 with IIS 6.0 is now available in an EPC for LANSA for the Web. Refer to EPC700 in the EPC information page.