If your website keeps growing and growing, eventually you will hit the error 500-13, that your server is too busy to handle the requests. What do you do?
First, check your main settings in IIS. Make sure you look in the PERFORMANCE tab. Set your site to more than 100,000 hits/day which is probably true if you are running into this error. Remember that hits includes every file you send out - including graphics - and is much larger than your page view count.
On that same page, be sure to turn off bandwidth throttling and process throttling.
Next, on your main entry in your IIS manager, right click to get properties. Go into Server Extensions - Settings. Depending on your use of include files and images, you may want to increase the cache sizes there.
To monitor the issue, open the performance monitor in your control panel. Right click on the lower right area to add a new item to monitor. You should add in -
ASP - requests queued
ASP - requests executing
ASP - script engines cached
Processor - % processor time
Memory - available bytes
I highly recommend using XCompress which is an ASP compressor, helping to ensure that you use as little bandwidth as possible in sending your ASP files out to end users.
If you want to take your life into your own hands, you can also try setting the cache settings manually. You need to launch a CMD prompt first. Head into inetpub\adminscripts. Then run commands:
adsutil set w3svc/1/AspQueueTimeout 30
adsutil set w3svc/1/ServerListenBackLog 500
adsutil set w3svc/1/MaxEndPointConnections 500
Those will help reduce your timeout from its unlimited initial state, and set higher limits on the backlog and max connections values. Be sure to backup before trying this!
In addition, you can go back into the IIS manager and right click for the properties. Go into Home Directory then Configuration. You get a special tab in here for Process Options that is not available on a single-website basis. Set the cache values up high enough based on the performance monitor entries.