I have a problem which I've tried to solve for several days now.
The customer was complaining that the system is slow. I ran SQL Server Profiler and saw that e g a stored procedure (RPC:Completed event class) runs 10 to 50 times slower than normal, but still with the same number of writes (about 400).
Having ruled out a lot of different hypothesis about the cause of this problem I landed in the fact that:
Depending on which web server making the call to the db server, the stored procedure performs differently!
I have the same binaries installed on each web server, so that should not be the problem. All remote calls from the different servers goes fast, except when the production server makes the call. Then the duration of the stored procedure is 10 to 50 times longer than for calls from the other servers.
The problem started with no connection to any known changes of the system, so that adds to the mystery, but the main mystery I want solved is the question above, namely why is the execution time for the stored procedures at the db server dependent on which web server calling??