Following my post about how to troubleshoot a low CPU performance issue with VSTS Test, I will now do the same for lab 4 where we have high CPU in GC. The scenario is pretty similar in that we have a page ( http://localhost/BuggyBits/AllProducts.aspx ) that seems to be taking a lot of time to execute. We also see that the w3wp.exe process sits at very high CPU ~100% during the time this page executes. Using Windbg in the lab, we saw that the issue here was that we were concatenating a very large string in a loop. This was generating a lot of full collections since we were constantly exhausting the large object heap, causing us to spend a lot of time in the GC. Check out the review for Lab 4 for more details on the issue. What...(read more) ...
Go to the complete details ...