Why is the ASP.NET/Visual Studio Web Development Server so slow?

Question

(xkcd)

I know that compiling nowadays is much faster than it was before. Yet, for me, it se

Answer 1

Check out if this helps:

http://blogs.msdn.com/b/mahuja/archive/2008/07/08/resolving-very-slow-symbol-loading-with-vs-2008-during-debugging.aspx

Answer 2

I was having the same problem. It ended up being a problem with ColdFusion being installed on my local machine (as painful as it is for me to admit). ColdFusion puts Handler Mappings named AboMapperCustom-* that were causing the latency. I uninstalled ColdFusion because I no longer need it (thank God). Another solution could be to remove each AboMapperCustom entry through the web.config. Example:

<handlers>
    <remove name="AboMapperCustom-15397" />
    <remove name="AboMapperCustom-20358" />
    <remove name="AboMapperCustom-47286" />
</handlers>

Make sure the 5-digits following AboMapperCustom- match those in your local IIS Handler Mappings.

HTH

Answer 3

There's no reason why it should take 3 minutes to start debugging something unless you've got something really strange going on.

I suggest you launch the debugger, try to navigate to a page and then just break into the debugger while it's loading. See where you're losing time. Maybe you're making some call on startup which is failing, but taking minutes to do so.

I've never experienced anything like what you're describing, which suggests it's either in your environment or in your code - and if it's a generally fast computer, that suggests it's somewhere in the code.

If you create a brand new MVC project and debug into that, does that take a long time?

You might also want to run Wireshark when you start debugging - see whether something in your app is trying to fetch a network resource of some description without you realising it.

Answer 4

I met the same problem these days, working under Win7, VS2010, and developing a Silverlight solution with 10+ projects. It takes about 3 minutes to launch IE, and waits 3 minutes to get back VS after closing IE. I overcame the problem by trying different ways. But the only valuable method:

1. Unload all projects not for debug
2. Start debug the solution (it works normal )
3. Reload other projects
4. VS works normal here. (VS works normal)

It seems the problem is just related with the VS environment on my side. It has nothing to do with ASP.NET Development Server or IIS.

Answer 5

This is actually a known performance issue with MVC, caused by throwing a ton of exceptions internally on startup. If you have IntelliTrace turned on, this will wreck havoc with it. Try disabling IntelliTrace and see if that improves it at all.

Source: http://connect.microsoft.com/VisualStudio/feedback/details/535799/debugging-mvc-is-very-very-slow

Answer 6

This is due to the IPv6 DNS problem within Firefox and can be fixed by setting the network.dns.disableIPv6 setting to true within the about:config

Slow DNS response - Firefox on localhost and Visual Studio or Cassini