Doesn't run "out of the box" on Mac OS X (System.IO.IOException: Too many open files)

[Daniel15]

Mono 3.12.0
Mac OS X Yosemite (10.10.2)

I made a site using the Yeoman generator (as per http://blogs.msdn.com/b/webdev/archive/2014/08/12/develop-asp-net-vnext-applications-on-a-mac.aspx), selected "Web Application" in the generator (which includes all the default sample pages), and tried running it unmodified:

yo aspnet
cd MyApp
kpm restore
kpm build
k kestrel

This resulted in a "Too many open files" exception:

danlo-mbp1:YoWebapp danlo$ k kestrel
System.IO.IOException: Too many open files
  at System.IO.FileStream..ctor (System.String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, Boolean anonymous, FileOptions options) [0x00000] in <filename unknown>:0
  at System.IO.FileStream..ctor (System.String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options) [0x00000] in <filename unknown>:0
  at (wrapper remoting-invoke-with-check) System.IO.FileStream:.ctor (string,System.IO.FileMode,System.IO.FileAccess,System.IO.FileShare,int,System.IO.FileOptions)
  at Microsoft.AspNet.FileProviders.PhysicalFileProvider+PhysicalFileInfo.CreateReadStream () [0x00000] in <filename unknown>:0
  at Microsoft.AspNet.Mvc.Razor.RazorPreCompiler.GetCacheEntry (Microsoft.AspNet.Mvc.Razor.RelativeFileInfo fileInfo) [0x00000] in <filename unknown>:0
  at Microsoft.AspNet.Mvc.Razor.RazorPreCompiler.OnCacheMiss (ICacheSetContext cacheSetContext) [0x00000] in <filename unknown>:0
  at Microsoft.Framework.Cache.Memory.CacheExtensions+<>c__DisplayClass7_0`1[Microsoft.AspNet.Mvc.Razor.PrecompilationCacheEntry].<Set>b__0 (ICacheSetContext context) [0x00000] in <filename unknown>:0
  at Microsoft.Framework.Cache.Memory.MemoryCache.Set (System.String key, IEntryLink link, System.Object state, System.Func`2 create) [0x00000] in <filename unknown>:0
  at Microsoft.Framework.Cache.Memory.CacheExtensions.Set (IMemoryCache cache, System.String key, System.Object state, System.Func`2 create) [0x00000] in <filename unknown>:0
  at Microsoft.Framework.Cache.Memory.CacheExtensions.Set[PrecompilationCacheEntry] (IMemoryCache cache, System.String key, System.Object state, System.Func`2 create) [0x00000] in <filename unknown>:0
  at Microsoft.Framework.Cache.Memory.CacheExtensions.GetOrSet[PrecompilationCacheEntry] (IMemoryCache cache, System.String key, System.Object state, System.Func`2 create) [0x00000] in <filename unknown>:0
  at Microsoft.AspNet.Mvc.Razor.RazorPreCompiler+<>c__DisplayClass17_0.<CreateCompilationDescriptors>b__0 (Int32 index) [0x00000] in <filename unknown>:0
  at System.Threading.Tasks.Parallel+<For>c__AnonStorey0.<>m__0 (Int32 index, System.Threading.Tasks.ParallelLoopState state) [0x00000] in <filename unknown>:0
  at System.Threading.Tasks.Parallel+<For>c__AnonStorey1.<>m__0 (Int32 i, System.Threading.Tasks.ParallelLoopState s, System.Object l) [0x00000] in <filename unknown>:0
  at System.Threading.Tasks.Parallel+<For>c__AnonStorey2`1[TLocal].<>m__0 () [0x00000] in <filename unknown>:0
  at System.Threading.Tasks.TaskActionInvoker+ActionInvoke.Invoke (System.Threading.Tasks.Task owner, System.Object state, System.Threading.Tasks.Task context) [0x00000] in <filename unknown>:0
  at System.Threading.Tasks.Task.InnerInvoke () [0x00000] in <filename unknown>:0
  at System.Threading.Tasks.Task.<ThreadStart>m__1 (System.Object l) [0x00000] in <filename unknown>:0
  at System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state) [0x00000] in <filename unknown>:0
  at System.Threading.Tasks.Task.ThreadStart () [0x00000] in <filename unknown>:0

I tried increasing the limit but I'm still getting the same exception. Are there other settings I need to set? Is this documented somewhere yet?

Thanks!

[samritchie]

+1

The HelloMvc sample from aspnet/Home runs, as does the yeoman EmptyApplication, but the WebApplication template doesn't. I might start randomly deleting stuff and see what works.

[samritchie]

yo generator is definitely generating beta3 dependencies. Yes, I managed to fix the incorrect HelloMVC versions.

Do you know if this specific issue is fixed in the dev builds? I've only just finished switching everything back to master.

[adaam2]

@antonmes That seemed to work for me. Thanks!

[Daniel15]

Awesome, thanks @antonmes! Do you know if there's a Mono bug number we can post here for reference?

[Daniel15]

Also note that MONO_MANAGED_WATCHER=disabled will totally disable file system watching, and I'm not sure if that will break anything or not. Perhaps I'll just try downgrading Mono, or using a Linux VM instead.

[Daniel15]

Ah I see, that explains a bug I encountered around a year ago: https://bugzilla.xamarin.com/show_bug.cgi?id=19071

[rynowak]

FYI if you find that you need to disable the filewatcher you may run into issues with timing when updating a .cshtml while the site is running. This is primarily what we're using it for.

@pranavkm in case he has thoughts

[Daniel15]

The Mono release notes say that it's only an issue when watching "very large directories". Maybe only watching the *.cshtml files rather than the whole directory could work around the issue? I haven't looked at the code so I'm not sure what it's doing.