New Relic and runAllManagedModulesForAllRequests flag in .net
I have been playing around with the awesome performance measuring tool New Relic lately and have been struggling with some performance issues that would have been hard to find without measuring the actual metrics from the real production server.
Anyway, during the different changes, I made I changed the option runAllManagedModulesForAllRequests from “true” to “false” in Web. Config and all of a sudden I got much worse numbers from New Relic compared to before this change. That was pretty weird since everyone said that this should be off for performance reasons.
Pretty soon I realized that the reason that the numbers got worse was that it stopped measuring the performance of scripts, style sheets, and images which of course is fast. Now I will continue with the mystery of the “System.Web.Handlers.TransferRequestHandler” method that is making my app slower for some reason.