Troubleshooting Performance Issues

From the perspective of a CMS developer, the first step in any performance investigation is to verify whether or not the performance issue is actually a CMS problem. The Microsoft PSS support team for CMS actually spends a good portion of its time chasing down problems that are not the result of a CMS issue.

To determine whether an issue is directly related to CMS, take as much of the code from the problematic template as possible and run it outside of a CMS context. In other words, put the code into a stand-alone ASPX (or ASP) page and see what sort of performance difference exists. If the code runs considerably faster outside of CMS, then you can start to think about CMS-specific considerations.

Obviously, this is more difficult to do if the code is using the CMS PAPI. But the key message is to not just assume that the issue is a CMS problem. Try to narrow it down to a particular template and then a particular section of code. You can do this by practicing the all-important methodology of "one thing at a time." Try removing each component until you find the code that is dragging.

Table 35-9 lists a number of issues and their possible causes and solutions.

Table 35-9. Troubleshooting Performance Issues

Behavior	Solution
Rate of cache misses is high.	Examine size and balance of caches. Ensure that output cache directives are correct and the durations are appropriate.
Rate of cache misses is high plus data access operations are high.	Adjust your cache settings and usage. This could also be the result of large searches try caching the most common searches.
Rate of cache misses is high plus number of master node cache items is high.	Increase the size of the master node cache ideally your peak node cache requirements should be around 80% of allocated node cache size to allow for shared nodes. You can also use this in conjunction with the ASP.NET performance counters for the output cache to trace the caching of data before MCMS.
Number of exceptions thrown by server is high.	Check the event log.
The cost for your authenticated users is much higher than for guest users.	Check your authentication mechanism for potential issues.
Web server is starved for resources.	Check the performance counters to see what is using the most resources.