Starting up a pretty small web app under VS2005 seems to take well over a minute. I don't see anything at all in the Output window for a quite a long time, then eventually see some messages about Build Started, then within a few seconds the application is up.

Under VS2003, the Build Started messages show up immediately, and the app (a much larger one) is up and running in 5 to 10 seconds.

Anybody know what is going on?

I don't know if it is relevant, but my My Documents is on a network drive, though in both cases the project itself lives on the local C: drive.

-- Matt

Hi Matt,

One possible cause of the problem is an issue we sometimes call "dueling references".  Can you confirm whether you have references to external assemblies in your project (you can check this by looking in your \bin directory for files with the .refresh extension)?

Also -- can you try doing a clean compile and seeing how long it takes.  Then, without making any code changes, try doing a "build solution" again and see if it takes the same amount of time.  If it does, then this is probably the dueling references issue.  If so, I can walk you through how to fix this.

Hope this helps,

Scott

Yes, I definitely have external references. I added the Enterprise Library dll's to my project. And now that you mention it, that is probably about the same time as when things started seeming slow.

Also, in addition to the Enterprise Library dll's, I had to separate some of my own code out into separate projects and create dll's. This is because I wanted to create my own CustomTraceListener for use with the Enterprise Library Logging package, but in order to configure that, you need an actual dll with your class in it (and web apps do not produce dll's).

So yes, I have a quite a few files in my webapp's Bin folder with the .dll.refresh extension.

Also, selecting Build Web Site, it takes about 65 seconds to see the first "Building Directory" message, and then it is complete in less than 5 seconds after that. Doing it again immediately after it takes about 50 seconds to see the Building Directory message.

Also, one other data point I forgot to mention, if I make a code change while the web app is already being debugged, it only takes a few seconds to recompile/reload. It is only the initial launch of the webapp (or the rebuild command) that is slow.

So it definitely sounds like "dueling references". Please let me know how to end this senseless feud!

Yep -- based on your description I'm almost ceretain it is the dueling references issue.  The delay it occurs only happens when you start a build -- which is why you aren't seeing when you make changes while under the debugger.

Basically, the .refresh files within your \bin directory contain a pointer path to an assembly to dynamically refresh in the project anytime it changes.  As part of this refresh process, it will also update and bring over other assemblies used by that target assembly if it has dependencies on it.  For example, if you have a .refresh file pointing to AssembyA.dll which has a dependency on AssemblyB.dll, both will get copied over into your \bin dircectoy whenever one changes.

What can happen is that you might have two or more .refresh files pointing to different assemblies -- and that some of those assemblies are built and have dependencies on different versions of files.

For example: You have two .refresh files -- one pointing to assemblya.dll and one pointing to assemblyc.dll.  Both have a dependency on assemblyb.dll, but the assemblyb.dll in their local directories are different versions.  As such, you can end up "refreshing" and copying it over, and doing a clean build, everytime you do a build or hit F5.  This will slow your build time down incredibly. 

There are a couple of ways to fix it:

1) Make sure any shared assemblies that you have references to are in sync and don't have version mis-matches.  This is the ideal approach and would be what I'd recommend unless there is some technical reason why they can't be versioned in sync.

2) Delete the .refresh files in your \bin directory.  The .refresh files are only needed if you want to dynamically update the assemblies on changes.  If you want to manually update an assembly, you can just delete its .refresh file (but keep the .dll). 

If you can't fix the cirtuclar reference in #1 and/or don't want to loose the dynamic update capability by doing #2, you can kind of cheat the build system by creating a new utility library as a class project.  Have this utility class project reference these dueling assemblies, and then reference the utility project from your web-project.  This will then cause all of the latest assemblies you need to be copied into the web project -- and avoid having the duplicate cause a reset each time.

Let me know if this works for you or if I can help more.

Thanks,

Scott

I deleted the .refresh files and build time has dropped from around 60 seconds to around 3 seconds!

Thanks for the help. If I get inspired I may try and sort out what the conflicts actually were. I had copied all the dll's out of the individual folders in the Enterprise Library and put them into one place before I added them as references to my project, so that may have something to do with the confusion.