Hello,

We've been fighting a critical issue on one of our DNN sites where the CPU is constantly maxing out at 100%.  The client is going berzerk about this...any help you can provide would be most appreciated.  Below is a writeup (in point form) of our situation.  Thanks in advance.

• ·         We have a client who is running DNN 4.5.3 on a Dual CPU server with 2 G of RAM. He has SQL server 2005 Workgroup version.
• ·         The site gets around 15,000 users a day mostly interacting with the forum module (Active Forum 3.6.10).
• ·         The site was up fine from mid-July to the end of October
• ·         By the end of October the site started to be very slow. For the last week, the site is almost an accessible at all.
• ·         By looking at the Task Manager we noticed that the CPU is almost at 100% all the time
• ·         If we look at the processes we see that the two services that are eating most of the CPU are;
• o   W3Wp.exe
• o   Sqlserver.exe
• ·         These two processes are running at 40% to 60% each alternating the consumption of the CPU.
• ·         We ran a trace and we noticed that there are a lot of calls to the stored procedure “Get Modules” and we noticed that it might be one of the tasks that is eating a lot of the CPU time (from the CPU column on the trace). We are not sure if this has to do with the problem or it is coming from something else. ? Is there any reason why the “get modules“ SP is called a lot and it is eating the CPU time.
• ·         It is good to note that on the same server, the client is running an exact replica site but it gets much less traffic, that second site is accessible all the time really fast regardless of the CPU usage. So at the same exact moment that we try to access the busy site and it is not even opening or taking 4 minutes to open, the light site is accessible and fast.
• ·         From the above we are not sure if the problem is really on the server side or SQL server being busy since why would it respond and render the light site and not the busy site. Could it be  a locking issue? Or other ASP.NET / OS level issues
• ·         We have also ran Perf Monitor and we added the "Packet Outbound Errors" counter to it and we are seeing it steady at 6 errors (around 6 dropped packets a sec) we have asked the hosting company to look into this although we are not sure if this could have anything to do with the above issue.

Try running, Select Count(*) from ScheduleHistory

If the count is greater than 500, do a, Truncate ScheduleHistory.

Read more here: http://www.efficionconsulting.com/Bloggings/tabid/594/ctl/Details/mid/1500/ItemID/501/Default.aspx