External component has thrown an exception, plus other errors

For the last several weeks, my site (Books2DVD.com) has been generating errors frequently, but not every time. The most common error is "External component has thrown an exception", but other errors include Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

The hosting company, Arvixe, is telling me that the Application Pool is running out of memory. But, I have no way of diagnosing that or verifying that.  They tell me the application pool is 800mb and recycles every 6 hours. This site is low traffic -- less than 20 visitors a day. There are about 4000 products. What could cause me to run out of memory so quickly? Or, is the application pool recycling part of the problem (the errors appear to come more often since they shortened the recycle period)?

I'm running version 2.80, with a few customizations, such as generating a customer pdf catalog, but few other changes. I do have the images in a the database, though I do not know if that is related.

How can I diagnose and solve the problem?

Brad Scott


Error
The log entry message.Short message:   External component has thrown an exception.
The details for the log entry.Full message:   System.Web.HttpCompileException (0x80004005): External component has thrown an exception. at System.Web.Compilation.AssemblyBuilder.Compile() at System.Web.Compilation.BuildProvidersCompiler.PerformBuild() at System.Web.Compilation.BuildManager.CompileWebFile(VirtualPath virtualPath) at System.Web.Compilation.BuildManager.GetVPathBuildResultInternal(VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate) at System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean allowBuildInPrecompile, Boolean throwIfNotFound, Boolean ensureIsUpToDate) at System.Web.Compilation.BuildManager.GetVirtualPathObjectFactory(VirtualPath virtualPath, HttpContext context, Boolean allowCrossApp, Boolean throwIfNotFound) at Nop.Web.Framework.Themes.ThemeableBuildManagerViewEngine.FileExists(ControllerContext controllerContext, String virtualPath) at Nop.Web.Framework.Themes.ThemeableVirtualPathProviderViewEngine.GetPathFromGeneralName(ControllerContext controllerContext, List`1 locations, String name, String controllerName, String areaName, String theme, String cacheKey, String[]& searchedLocations) at Nop.Web.Framework.Themes.ThemeableVirtualPathProviderViewEngine.GetPath(ControllerContext controllerContext, String[] locations, String[] areaLocations, String locationsPropertyName, String name, String controllerName, String theme, String cacheKeyPrefix, Boolean useCache, Boolean mobile, String[]& searchedLocations) at Nop.Web.Framework.Themes.ThemeableVirtualPathProviderViewEngine.FindThemeableView(ControllerContext controllerContext, String viewName, String masterName, Boolean useCache, Boolean mobile) at Nop.Web.Framework.Themes.ThemeableVirtualPathProviderViewEngine.FindView(ControllerContext controllerContext, String viewName, String masterName, Boolean useCache) at System.Web.Mvc.ViewEngineCollection.<>c__DisplayClassc.<FindView>b__a(IViewEngine e) at System.Web.Mvc.ViewEngineCollection.Find(Func`2 lookup, Boolean trackSearchedPaths) at System.Web.Mvc.ViewEngineCollection.FindView(ControllerContext controllerContext, String viewName, String masterName) at System.Web.Mvc.ViewResult.FindView(ControllerContext context) at System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context) at System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult) at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1a.<InvokeActionResultWithFilters>b__17() at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1a.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19() at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1a.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19() at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1a.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19() at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1a.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19() at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult) at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass25.<>c__DisplayClass2a.<BeginInvokeAction>b__20() at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End() at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) at System.Web.Mvc.Controller.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End() at System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End() at System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) at System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) at System.Web.Mvc.MvcHandler.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End() at System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) at System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
IP address of the machine that caused the exception.IP address:   50.89.255.218
Name of the customer who caused the exception.Customer:  [email protected]
Originating page of exception.Page URL:   https://books2dvd.com/admin/common/systeminfo
The referrer URL.Referrer URL:   /Admin/Topic/List
Date/Time the log entry was created.Created on:   6/27/2013 10:04:04 AM

The error turned out to be caused by the Application Pool set to only 300mb. Arvixe set the value to 800mb in the wrong place, so the limit remained at 300mb. But, I did learn an important lesson here. First, the application hovers around 295mb to 305 mb, depending on what function the user is doing. So, NopCommerce will fail with less than a 310mb Application Pool limit -- 500mb or more is much safer.

Second, when choosing a hosting company, be sure you can get a 400mb or greater Application Pool limit. I checked, and many use 250mb or less. Arvixe has higher limits on the Business accounts. The key is to check before selecting a hosting company and plan.