Ok, here's the scenario:
DNN 04.08.02 (yes I know, upgrade)
Portals: 349
Tabs: 92464
Problem: Every so often, we see periods of time where our database server spikes both CPU's to 100% and stays there. At which point the portals either slow down or time out. The webserver is usually running at like 20% (or less) during these events. I run the SQL profiler and I see some odd things. For one it appears that I'm seeing multiple repeated requests.
We see something like this:
RPC:Completed exec dbo.GetPortalAliasByPortalID @PortalID=629
RPC:Completed exec dbo.GetPortalAliasByPortalID @PortalID=575
RPC:Completed exec dbo.GetPortalAliasByPortalID @PortalID=629
RPC:Completed exec dbo.GetPortalAliasByPortalID @PortalID=575
It does this dozens of times. At some point it ends up going onto other requests and other portals.
The application isn't getting restarted. There are no odd events in the application event log. Sometimes
the system recovers on it's own, other times I have to restart IIS (which coincidentally takes a VERY VERY
long time to stop)
90% of the time the system runs along at like 4-10% cpu with very brief spikes higher, when these events
happen it's like a plateu, not a spike.
Any ideas?
Thanks.