Confused about ISAPI

[archer]

Hello Friend,

I am Bsc(IT) student, and having lots of confusion about the ISAPI. I am getting troubled while use of ISAPI concept. I have referred various books for ISAPI, but nothing was helpful. If you posses sound knowledge about ISAPI concept, then please let me aware about the same. I would really appreciate any help over ISAPI. I am waiting for your reply.

[Praetor]

The ISAPI is the programming interface (APIs) for application IIS of Microsoft. It was designed by Process Software Corporation, Microsoft Corporation and a few other publishers. The objective is to limit the creation of the son process to reduce latency. To do this, load the ISAPI code from the shared Dll in the server process. The disadvantage of ISAPI, compared for example CGIIs that the code loaded into the server compromises its integrity.

[Katty]

ISAPI is mainly used in the version "WebServer" of Windows Server 2003. ISAPI has also been implemented by Apache via its module mod_isapi that allows Web applications written to run on IIS to Apache. When a browser requests a connection type Default.asp, IIS (w3wp.exe or aspnet_wp.exe) intercepts the web request and after analyzing the file extension and the password is the name ISAPI From ssi.dll . SSI is a default service supported internally by IIS, but this service can be moved as a link library (DLL) compatible ISAPI.

[kelfro]

The biggest demerits of ISAPI is the increase in ISAPI development time compared to technologies like PHP and ASP support native session management. Security problems also appear because of the use of C language and the possibility of saturation of the cache (buffer overflows). Unlike a CGI, ISAPI version 5.0 and earlier is enforced in the same workspace as IIS.

[Reegan]

ISAPI filters are used to modify or improve the functionality offered by IIS by default. The configuration file for IIS defines the execution order of filters and level (sites or directories). Implemented as DLLs, the filters are always loaded in IIS in the background. They examine and modify, if necessary, the data passing through the http protocol. It is used to Change the header and the url requested by the client .

[opaper]

Please refer following limitations of the ISAPI:

• They have access only header of the html page not the body
• They are configured for a site not for a virtual directory
• They work on synchronous and block the user interface so long calculation
• They have access to fewer features than the ISAPI applications