What is the .NET equivalent of java's -verbose:gc command line option

Question

I'm writting an ASP.NET MVC application and I'm seeing a seemly random performance from a one of my actions. My initial throught is that the garbage collection is kicking in and pausing the app for a little while, but I can't seem to find a button/switch that will prove or disprove my theory.

For none java people out there -verbose:gc is a command line switch that you can pass to a java application that will make the JVM print out when a GC event happens and how long it takes.

I've attempted to use the vs2010 performance tool and JetBrains dotTrace both of which are a little bit like using a thermo nuclear weapon to crack a small nut.

Answer 1

In .NET 4.0 there is Event tracing for Windows (ETW) that provides you with the information you are looking for. Here is a one specific for GC .

FYI ETW is very fast and built into Kernel. With ETW you should be able to get information like this

And to get this information there is a tool from the BCL team which is called PerfMonitor

Here are the steps in using the tool to get the GC Information

1. Start a cmd or powershell as admin , this required to collect ETW tracing
2. Start the application that you want to trace
3. Issue the command “PerfMonitor.exe /process:4180 start” where 4180 is the process id
4. Do the necessary actions
5. Then issue “PerfMonitor.exe stop”
6. The command to get the report “PerfMonitor.exe GCTime”. This will generate a report and open it in the browser

I have also blogged the about the same

HTH

Answer 2

Your first guess should not be the GC. With all normal workloads you don't notice the GC in .NET.

There is no trace-switch for the GC, but you can look at the performance counters if you still think the GC is to blame.