Throughout this manual, the WebSpeed Messenger that has been described is cgiip or cgiip.exe. Depending on your Web server, there are alternate WebSpeed Messengers. If you are using a Microsoft IIS Web server, you can use the wsisa.dll Messenger, and if you are using the Netscape/iPlanet Web server, which is now part of SunOne, you can use the nsapi.dll.
Each of these Messengers acts in exactly the same way as cgiip, but because they are Dynamic Link Libraries (DLLs), they stay in memory and are faster to execute the next time they are called.
Being a DLL does have a drawback. If the Web server gets confused, there is a strong possibility that the Messenger process will stop working. The only way to correct this is to restart the Web server process on the Web server machine; sometimes this involves a reboot.
Because the cgiip Messenger being loaded each time a request is made, it is slower than the DLL versions, but it is also more reliable. Since the time it takes the cgiip Messenger to load itself into memory is quite small, using cgiip is a good idea for production Web sites, as the performance overhead is slight, but the reliability is high. You should test each possible Messenger for performance and determine which one you want to use. During testing, remember to time the entire application, not just the Messenger load times.
