IIS/ASP Request Wait Time Need Advice

Question

We are running an ASP application using ASP 2.0.50727 running on IIS 6.0 and Windows 2003. We are having random high response times and I can see using PerfMon at times we have ASP\Request Wait Times of 5-14 seconds. The corresponding ASP\Requests Queued are 6-12. I looked in our ASP Machine.config and the we are set to AutoConfig which should automatically configure all the connection values properly. We are not having any physical level issues, CPU is about 10%, memory is 15%,etc.

What else can I look at? Should we remove the AutoConfig and try and manually change all the values? Thanks for any guidance.

Answer 1

As far as I know the settings in machine.config do not affect classic ASP. All classic ASP settings are stored in applicationHost.config (globally) or with a <location> tag for a specific site. IIS Manager shows the location of the configuration in the bottom status bar when you change the settings.

Back to your problem, you might want to read Monitoring ASP Performance on TechNet. I think that tuning the AspProcessorThreadMax setting might also be a solution for your problem. It seems like you have a few running requests causing other requests to get queued up.

Answer 2

Perfmon is a good tool when you know exactly what you want to measure, but for looking up bottlenecks I'd go for Process Explorer first to get a general overview and if that reveals anything zoom in with xperf or another profiler.

If your ASP application is using a database, try using a database profiler to check the query's. Ten to one, database interoperability is the culprit. Often retrieval of entire tables just to show a portion or other similar overhead.

It may also be a network latency problem where the database needs to be accessed multiple times with query's that depend on previous query's results. These latency problems are sometimes difficult to discover (especially if you're not a developer) since they do not always show excessive resource usage in tools such as process explorer or PerfMon.