When recycling the IIS worker process or restarting IIS all together, the first request to the website starts up the Umbraco application. We are seeing the startup of the application taking at least 5 minutes and up to 10 minutes. During the startup CPU utilization on the server is pegged at 100%.

The server is a virtual machine with 2 cores running Windows Server 2012 on XenServer 6.2. Below is the log file during startup. The last log entry occurs fairly quickly in the startup process, but the application does not return the first page request (and the CPU stays at 100%) until some 5-10 minutes later. So my theory is there's something in the startup that isn't being logged that's taking up that time & CPU.

We're also seeing slow page load times of ~1.5 seconds with large spikes in CPU usage for each request.

The startup time on my local developer machine (Win7, 4 cores) is less than 30 seconds when run via Visual Studio 2012 with IIS Express. Page load times are still a bit slow, but quicker than on the server (~500ms).

Server log file:

2013-10-02 08:52:26,958 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Determining hash of code files on disk
2013-10-02 08:52:26,974 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Hash determined (took 7ms)
2013-10-02 08:52:26,974 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Starting resolution types of umbraco.interfaces.IApplicationStartupHandler
2013-10-02 08:52:27,161 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Completed resolution of types of umbraco.interfaces.IApplicationStartupHandler, found 20 (took 179ms)
2013-10-02 08:52:27,161 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Starting resolution types of Umbraco.Core.PropertyEditors.IPropertyEditorValueConverter
2013-10-02 08:52:27,161 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Completed resolution of types of Umbraco.Core.PropertyEditors.IPropertyEditorValueConverter, found 0 (took 5ms)
2013-10-02 08:52:27,161 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Starting resolution types of Umbraco.Web.Mvc.SurfaceController
2013-10-02 08:52:27,177 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Completed resolution of types of Umbraco.Web.Mvc.SurfaceController, found 0 (took 4ms)
2013-10-02 08:52:27,177 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Starting resolution types of Umbraco.Web.WebApi.UmbracoApiController
2013-10-02 08:52:27,177 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Completed resolution of types of Umbraco.Web.WebApi.UmbracoApiController, found 3 (took 4ms)
2013-10-02 08:52:27,177 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Starting resolution types of Umbraco.Core.Media.IThumbnailProvider
2013-10-02 08:52:27,192 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Completed resolution of types of Umbraco.Core.Media.IThumbnailProvider, found 3 (took 6ms)
2013-10-02 08:52:27,192 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Starting resolution types of Umbraco.Core.Media.IImageUrlProvider
2013-10-02 08:52:27,192 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Completed resolution of types of Umbraco.Core.Media.IImageUrlProvider, found 1 (took 6ms)
2013-10-02 08:52:27,426 [7] INFO  Umbraco.Web.Search.ExamineEvents - [Thread 1] Initializing Examine and binding to business logic events
2013-10-02 08:52:27,660 [7] INFO  Umbraco.Web.Search.ExamineEvents - [Thread 1] Adding examine event handlers for index providers: 4
2013-10-02 08:52:27,660 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Starting resolution types of umbraco.interfaces.IApplication
2013-10-02 08:52:27,676 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Completed resolution of types of umbraco.interfaces.IApplication, found 7 (took 15ms)
2013-10-02 08:52:27,723 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Starting resolution types of umbraco.interfaces.ITree
2013-10-02 08:52:27,769 [7] INFO  Umbraco.Core.PluginManager - [Thread 1] Completed resolution of types of umbraco.interfaces.ITree, found 27 (took 43ms)
2013-10-02 08:52:27,925 [7] INFO  umbraco.content - [Thread 9] Loading content from disk cache...
2013-10-02 08:52:32,980 [7] INFO  Umbraco.Core.PluginManager - [Thread 9] Starting resolution types of Umbraco.Core.Persistence.Mappers.BaseMapper
2013-10-02 08:52:32,980 [7] INFO  Umbraco.Core.PluginManager - [Thread 9] Completed resolution of types of Umbraco.Core.Persistence.Mappers.BaseMapper, found 17 (took 7ms)
(THIS IS WHERE IT HUNG FOR 7 MINUTES WITH 100% CPU USAGE. NO FURTHER LOG ENTRIES)