Search Results

Search found 93573 results on 3743 pages for 'system net mail'.

Page 28/3743 | < Previous Page | 24 25 26 27 28 29 30 31 32 33 34 35  | Next Page >

• ASP MVC.Net 3 RC2 bug ?

  - by Jarek Waliszko

  Hello, so far I've been using ASP.Net 3 BETA. Everything was working fine till the update to RC2 version. Of course I've read ScottGu's article about RC2. My problem is following. Basically I have 2 controllers: public class DynamicPageController : Controller { public ActionResult Redirect(string resource, int? pageNumber, int? id) { } } public class SystemController : Controller { public ActionResult Index() { } } In the Globals.asax I have routes like this: public static void RegisterRoutes(RouteCollection routes) { routes.MapRoute( "SystemRoute", "System/{action}", new { controller = "System", action = "Index" } ); routes.MapRoute( "PageRoute", "{resource}/{id}/{pageNumber}", new { controller = "DynamicPage", action = "Redirect", resource = UrlParameter.Optional, pageNumber = UrlParameter.Optional, id = UrlParameter.Optional } ); } In the code, I have simple link creation: System.Web.Mvc.UrlHelper u = new System.Web.Mvc.UrlHelper(context); string url = u.Action("Index", "System"); and the url is "/my_app/System" in both versions (BETA and RC2) But the code below (the syntax is the same as above, only controller and action names are different): string url = u.Action("Redirect", "DynamicPage", new RouteValueDictionary(new { resource = "Home" })); gives url which is null in RC2. It should be (and in fact in BETA was) "/my_app/Home" Why ? Is it a bug ? How can I create url for my "DynamicPage" controller ? Regards BTW: From where can I now download ASP.Mvc BETA version along with ASP.Net Web Pages 1.0 installers ? Since RC2 announcement I have problems finding mentioned 2 installers. Normally I would upgrade my code but this issue described above makes me stay with BETA for a while, since I have no time for migration and testing everything now.

  Read the article

• .net 4.5 Asp Mvc -> Error 403.14- IIS 7 - Windows Server 2008 R2

  - by Boas Enkler

  When I want to deploy an MVC 4 (.net 4.5) application to my iis i got the 403.14 calling me that the content ist not browseable. This also occurs when i deploy the unchanged mvc 4 template. when using the mvc 4 template with .net 4.0 everything works. I checked the other posts but can't figure out the solution. ist set i ran aspnet_regiss -i which completed without any errors. the only strange thing is that .net 4.5 is installed in the .net 4.0 directory %windows%/microsoft.net/Framework64/4.0.30319 From this folder i also ran aspnet_regiis. to ensure that 4.5 is installed i restarted the .net 4.5 setup and it tells me taht it is installes Also the apppools show me 4.0.30319 as version. There is an other application targeting mvc with 4.5 which runs. but i don't know wether it was created with a 4.0 templated and retargeted to 4.5 Any hints? The app.config is the unchanged default from the mvc 4 template. I just tested to create a subfolder which i convert to an application. placing the site there makes it working. But why not on root folder?

  Read the article

• asp.net membership create user error

  - by nitroxn

  Hi, I encountered an issue while creating users using the asp.net user membership. The membership provider configuration is as follows- The error generated by ASP.net configuration application is as follows- An error was encountered. Please return to the previous page and try again. The following message may help in diagnosing the problem: Exception has been thrown by the target of an invocation. at System.RuntimeMethodHandle._InvokeMethodFast(IRuntimeMethodInfo method, Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeType typeOwner) at System.RuntimeMethodHandle.InvokeMethodFast(IRuntimeMethodInfo method, Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeType typeOwner) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at System.Web.Administration.WebAdminMembershipProvider.CallWebAdminMembershipProviderHelperMethodOutParams(String methodName, Object[] parameters, Type[] paramTypes) at System.Web.Administration.WebAdminMembershipProvider.CreateUser(String username, String password, String email, String passwordQuestion, String passwordAnswer, Boolean isApproved, Object providerUserKey, MembershipCreateStatus& status) at System.Web.UI.WebControls.CreateUserWizard.AttemptCreateUser() at System.Web.UI.WebControls.CreateUserWizard.OnNextButtonClick(WizardNavigationEventArgs e) at System.Web.UI.WebControls.Wizard.OnBubbleEvent(Object source, EventArgs e) at System.Web.UI.WebControls.CreateUserWizard.OnBubbleEvent(Object source, EventArgs e) at System.Web.UI.WebControls.Wizard.WizardChildTable.OnBubbleEvent(Object source, EventArgs args) at System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) at System.Web.UI.WebControls.Button.OnCommand(CommandEventArgs e) at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

  Read the article

• Parallelism in .NET – Part 14, The Different Forms of Task

  - by Reed

  Before discussing Task creation and actual usage in concurrent environments, I will briefly expand upon my introduction of the Task class and provide a short explanation of the distinct forms of Task.  The Task Parallel Library includes four distinct, though related, variations on the Task class. In my introduction to the Task class, I focused on the most basic version of Task.  This version of Task, the standard Task class, is most often used with an Action delegate.  This allows you to implement for each task within the task decomposition as a single delegate. Typically, when using the new threading constructs in .NET 4 and the Task Parallel Library, we use lambda expressions to define anonymous methods.  The advantage of using a lambda expression is that it allows the Action delegate to directly use variables in the calling scope.  This eliminates the need to make separate Task classes for Action<T>, Action<T1,T2>, and all of the other Action<…> delegate types.  As an example, suppose we wanted to make a Task to handle the ”Show Splash” task from our earlier decomposition.  Even if this task required parameters, such as a message to display, we could still use an Action delegate specified via a lambda: // Store this as a local variable string messageForSplashScreen = GetSplashScreenMessage(); // Create our task Task showSplashTask = new Task( () => { // We can use variables in our outer scope, // as well as methods scoped to our class! this.DisplaySplashScreen(messageForSplashScreen); }); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This provides a huge amount of flexibility.  We can use this single form of task for any task which performs an operation, provided the only information we need to track is whether the task has completed successfully or not.  This leads to my first observation: Use a Task with a System.Action delegate for any task for which no result is generated. This observation leads to an obvious corollary: we also need a way to define a task which generates a result.  The Task Parallel Library provides this via the Task<TResult> class. Task<TResult> subclasses the standard Task class, providing one additional feature – the ability to return a value back to the user of the task.  This is done by switching from providing an Action delegate to providing a Func<TResult> delegate.  If we decompose our problem, and we realize we have one task where its result is required by a future operation, this can be handled via Task<TResult>.  For example, suppose we want to make a task for our “Check for Update” task, we could do: Task<bool> checkForUpdateTask = new Task<bool>( () => { return this.CheckWebsiteForUpdate(); }); Later, we would start this task, and perform some other work.  At any point in the future, we could get the value from the Task<TResult>.Result property, which will cause our thread to block until the task has finished processing: // This uses Task<bool> checkForUpdateTask generated above... // Start the task, typically on a background thread checkForUpdateTask.Start(); // Do some other work on our current thread this.DoSomeWork(); // Discover, from our background task, whether an update is available // This will block until our task completes bool updateAvailable = checkForUpdateTask.Result; This leads me to my second observation: Use a Task<TResult> with a System.Func<TResult> delegate for any task which generates a result. Task and Task<TResult> provide a much cleaner alternative to the previous Asynchronous Programming design patterns in the .NET framework.  Instead of trying to implement IAsyncResult, and providing BeginXXX() and EndXXX() methods, implementing an asynchronous programming API can be as simple as creating a method that returns a Task or Task<TResult>.  The client side of the pattern also is dramatically simplified – the client can call a method, then either choose to call task.Wait() or use task.Result when it needs to wait for the operation’s completion. While this provides a much cleaner model for future APIs, there is quite a bit of infrastructure built around the current Asynchronous Programming design patterns.  In order to provide a model to work with existing APIs, two other forms of Task exist.  There is a constructor for Task which takes an Action<Object> and a state parameter.  In addition, there is a constructor for creating a Task<TResult> which takes a Func<Object, TResult> as well as a state parameter.  When using these constructors, the state parameter is stored in the Task.AsyncState property. While these two overloads exist, and are usable directly, I strongly recommend avoiding this for new development.  The two forms of Task which take an object state parameter exist primarily for interoperability with traditional .NET Asynchronous Programming methodologies.  Using lambda expressions to capture variables from the scope of the creator is a much cleaner approach than using the untyped state parameters, since lambda expressions provide full type safety without introducing new variables.

  Read the article

• sendmail working but PHP mail() is failing

  - by navilon

  I cant seem to send an email using PHP's mail(). I have also tried PHPMailer and Swiftmail with no success. However, the following command on the server delivers mail successfully. cat test.txt | mail -s "test mail" [email protected] Is there a way to trace where the problem is coming from? mail() just seems to return true or false.

  Read the article

• How to host customer developed code server side

  - by user963263

  I'm developing a multi-tenant web application, most likely using ASP.NET MVC5 and Web API. I have used business applications in the past where it was possible to upload custom DLL's or paste in custom code to a GUI to have custom functions run server side. These applications were self hosted and single-tenant though so the customer developed bits didn't impact other clients. I want to host the multi-tenant web application myself and allow customers to upload custom code that will run server side. This could be for things like custom web services that client side JavaScript could interact with, or it could be for automation steps that they want triggered server side asynchronously when a user takes a particular action. Additionally, I want to expose an API that allows customers' code to interact with data specific to the web application itself. Client code may need to be "wrapped" so that it has access to appropriate references - to our custom API and maybe to a white list of approved libraries. There are several issues to consider - security, performance (infinite loops, otherwise poorly written code, load balancing, etc.), receive compiled DLL's or require raw code, etc. Is there an established pattern for this sort of thing or a sample project anyone can point to? Or any general recommendations?

  Read the article

• Custom ASPNetMembership FailureInformation always null, OnValidatingPassword issue

  - by bigb

  As stated here http://msdn.microsoft.com/en-us/library/system.web.security.membershipprovider.onvalidatingpassword.aspx "When the ValidatingPassword event has completed, the properties of the ValidatePasswordEventArgs object supplied as the e parameter can be examined to determine whether the current action should be canceled and if a particular Exception, stored in the FailureInformation property, should be thrown." Here is some details/code which really shows why FailureInformation shouldn't be always null http://forums.asp.net/t/991002.aspx if any password security conditions not matched. According with my Membership settings i should get an exception that password does not match password security conditions, but it is not happened. Then i did try to debug System.Web.ApplicationServices.dll(in .NET 4.0 System.Web.Security located here) Framework Code to see whats really happens there, but i cant step into this assembly, may be because of this [TypeForwardedFrom("System.Web, Version=2.0.0.0, Culture=Neutral, PublicKeyToken=b03f5f7f11d50a3a")] public abstract class MembershipProvider : ProviderBase Easily i may step into any another .NET 4.0 assembly, but in this one not. I did check, symbols for System.Web.ApplicationServices.dll loaded. Now i have only one idea how ti fix it - to override method OnValidatingPassword(ValidatePasswordEventArgs e). Thats my story. May be some one may help: 1) Any ideas why OnValidatingPassword not working? 2) Any ideas how to step into it?

  Read the article

• .Net 3.5 Chart Controls Exception

  - by ChrisHDog

  I am using the new free .net chart controls and they appear to work fine when I run the project up in visual studio, but when hitting the same via IIS I get and exception: [HttpException (0x80004005): No http handler was found for request type 'GET'] System.Web.HttpApplication.MapIntegratedHttpHandler(HttpContext context, String requestType, VirtualPath path, String pathTranslated, Boolean useAppConfig, Boolean convertNativeStaticFileModule) +529 System.Web.HttpServerUtility.Execute(String path, TextWriter writer, Boolean preserveForm) +947 [HttpException (0x80004005): Error executing child request for ChartImg.axd.] System.Web.HttpServerUtility.Execute(String path, TextWriter writer, Boolean preserveForm) +4120098 System.Web.UI.DataVisualization.Charting.ChartHttpHandler.EnsureInitialized(Boolean hardCheck) +266 System.Web.UI.DataVisualization.Charting.Chart.GetImageStorageMode() +25 System.Web.UI.DataVisualization.Charting.Chart.Render(HtmlTextWriter writer) +133 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +240 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +240 System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer) +253 System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output) +87 System.Web.UI.HtmlControls.HtmlForm.RenderControl(HtmlTextWriter writer) +53 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +240 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +240 System.Web.UI.Page.Render(HtmlTextWriter writer) +38 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +4240 Any idea what I'm doing wrong? Thanks!

  Read the article

• Parallelism in .NET – Part 11, Divide and Conquer via Parallel.Invoke

  - by Reed

  Many algorithms are easily written to work via recursion.  For example, most data-oriented tasks where a tree of data must be processed are much more easily handled by starting at the root, and recursively “walking” the tree.  Some algorithms work this way on flat data structures, such as arrays, as well.  This is a form of divide and conquer: an algorithm design which is based around breaking up a set of work recursively, “dividing” the total work in each recursive step, and “conquering” the work when the remaining work is small enough to be solved easily. Recursive algorithms, especially ones based on a form of divide and conquer, are often a very good candidate for parallelization. This is apparent from a common sense standpoint.  Since we’re dividing up the total work in the algorithm, we have an obvious, built-in partitioning scheme.  Once partitioned, the data can be worked upon independently, so there is good, clean isolation of data. Implementing this type of algorithm is fairly simple.  The Parallel class in .NET 4 includes a method suited for this type of operation: Parallel.Invoke.  This method works by taking any number of delegates defined as an Action, and operating them all in parallel.  The method returns when every delegate has completed: Parallel.Invoke( () => { Console.WriteLine("Action 1 executing in thread {0}", Thread.CurrentThread.ManagedThreadId); }, () => { Console.WriteLine("Action 2 executing in thread {0}", Thread.CurrentThread.ManagedThreadId); }, () => { Console.WriteLine("Action 3 executing in thread {0}", Thread.CurrentThread.ManagedThreadId); } ); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Running this simple example demonstrates the ease of using this method.  For example, on my system, I get three separate thread IDs when running the above code.  By allowing any number of delegates to be executed directly, concurrently, the Parallel.Invoke method provides us an easy way to parallelize any algorithm based on divide and conquer.  We can divide our work in each step, and execute each task in parallel, recursively. For example, suppose we wanted to implement our own quicksort routine.  The quicksort algorithm can be designed based on divide and conquer.  In each iteration, we pick a pivot point, and use that to partition the total array.  We swap the elements around the pivot, then recursively sort the lists on each side of the pivot.  For example, let’s look at this simple, sequential implementation of quicksort: public static void QuickSort<T>(T[] array) where T : IComparable<T> { QuickSortInternal(array, 0, array.Length - 1); } private static void QuickSortInternal<T>(T[] array, int left, int right) where T : IComparable<T> { if (left >= right) { return; } SwapElements(array, left, (left + right) / 2); int last = left; for (int current = left + 1; current <= right; ++current) { if (array[current].CompareTo(array[left]) < 0) { ++last; SwapElements(array, last, current); } } SwapElements(array, left, last); QuickSortInternal(array, left, last - 1); QuickSortInternal(array, last + 1, right); } static void SwapElements<T>(T[] array, int i, int j) { T temp = array[i]; array[i] = array[j]; array[j] = temp; } Here, we implement the quicksort algorithm in a very common, divide and conquer approach.  Running this against the built-in Array.Sort routine shows that we get the exact same answers (although the framework’s sort routine is slightly faster).  On my system, for example, I can use framework’s sort to sort ten million random doubles in about 7.3s, and this implementation takes about 9.3s on average. Looking at this routine, though, there is a clear opportunity to parallelize.  At the end of QuickSortInternal, we recursively call into QuickSortInternal with each partition of the array after the pivot is chosen.  This can be rewritten to use Parallel.Invoke by simply changing it to: // Code above is unchanged... SwapElements(array, left, last); Parallel.Invoke( () => QuickSortInternal(array, left, last - 1), () => QuickSortInternal(array, last + 1, right) ); } This routine will now run in parallel.  When executing, we now see the CPU usage across all cores spike while it executes.  However, there is a significant problem here – by parallelizing this routine, we took it from an execution time of 9.3s to an execution time of approximately 14 seconds!  We’re using more resources as seen in the CPU usage, but the overall result is a dramatic slowdown in overall processing time. This occurs because parallelization adds overhead.  Each time we split this array, we spawn two new tasks to parallelize this algorithm!  This is far, far too many tasks for our cores to operate upon at a single time.  In effect, we’re “over-parallelizing” this routine.  This is a common problem when working with divide and conquer algorithms, and leads to an important observation: When parallelizing a recursive routine, take special care not to add more tasks than necessary to fully utilize your system. This can be done with a few different approaches, in this case.  Typically, the way to handle this is to stop parallelizing the routine at a certain point, and revert back to the serial approach.  Since the first few recursions will all still be parallelized, our “deeper” recursive tasks will be running in parallel, and can take full advantage of the machine.  This also dramatically reduces the overhead added by parallelizing, since we’re only adding overhead for the first few recursive calls.  There are two basic approaches we can take here.  The first approach would be to look at the total work size, and if it’s smaller than a specific threshold, revert to our serial implementation.  In this case, we could just check right-left, and if it’s under a threshold, call the methods directly instead of using Parallel.Invoke. The second approach is to track how “deep” in the “tree” we are currently at, and if we are below some number of levels, stop parallelizing.  This approach is a more general-purpose approach, since it works on routines which parse trees as well as routines working off of a single array, but may not work as well if a poor partitioning strategy is chosen or the tree is not balanced evenly. This can be written very easily.  If we pass a maxDepth parameter into our internal routine, we can restrict the amount of times we parallelize by changing the recursive call to: // Code above is unchanged... SwapElements(array, left, last); if (maxDepth < 1) { QuickSortInternal(array, left, last - 1, maxDepth); QuickSortInternal(array, last + 1, right, maxDepth); } else { --maxDepth; Parallel.Invoke( () => QuickSortInternal(array, left, last - 1, maxDepth), () => QuickSortInternal(array, last + 1, right, maxDepth)); } We no longer allow this to parallelize indefinitely – only to a specific depth, at which time we revert to a serial implementation.  By starting the routine with a maxDepth equal to Environment.ProcessorCount, we can restrict the total amount of parallel operations significantly, but still provide adequate work for each processing core. With this final change, my timings are much better.  On average, I get the following timings: Framework via Array.Sort: 7.3 seconds Serial Quicksort Implementation: 9.3 seconds Naive Parallel Implementation: 14 seconds Parallel Implementation Restricting Depth: 4.7 seconds Finally, we are now faster than the framework’s Array.Sort implementation.

  Read the article

• Parallelism in .NET – Part 20, Using Task with Existing APIs

  - by Reed

  Although the Task class provides a huge amount of flexibility for handling asynchronous actions, the .NET Framework still contains a large number of APIs that are based on the previous asynchronous programming model.  While Task and Task<T> provide a much nicer syntax as well as extending the flexibility, allowing features such as continuations based on multiple tasks, the existing APIs don’t directly support this workflow. There is a method in the TaskFactory class which can be used to adapt the existing APIs to the new Task class: TaskFactory.FromAsync.  This method provides a way to convert from the BeginOperation/EndOperation method pair syntax common through .NET Framework directly to a Task<T> containing the results of the operation in the task’s Result parameter. While this method does exist, it unfortunately comes at a cost – the method overloads are far from simple to decipher, and the resulting code is not always as easily understood as newer code based directly on the Task class.  For example, a single call to handle WebRequest.BeginGetResponse/EndGetReponse, one of the easiest “pairs” of methods to use, looks like the following: var task = Task.Factory.FromAsync<WebResponse>( request.BeginGetResponse, request.EndGetResponse, null); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The compiler is unfortunately unable to infer the correct type, and, as a result, the WebReponse must be explicitly mentioned in the method call.  As a result, I typically recommend wrapping this into an extension method to ease use.  For example, I would place the above in an extension method like: public static class WebRequestExtensions { public static Task<WebResponse> GetReponseAsync(this WebRequest request) { return Task.Factory.FromAsync<WebResponse>( request.BeginGetResponse, request.EndGetResponse, null); } } This dramatically simplifies usage.  For example, if we wanted to asynchronously check to see if this blog supported XHTML 1.0, and report that in a text box to the user, we could do: var webRequest = WebRequest.Create("http://www.reedcopsey.com"); webRequest.GetReponseAsync().ContinueWith(t => { using (var sr = new StreamReader(t.Result.GetResponseStream())) { string str = sr.ReadLine();; this.textBox1.Text = string.Format("Page at {0} supports XHTML 1.0: {1}", t.Result.ResponseUri, str.Contains("XHTML 1.0")); } }, TaskScheduler.FromCurrentSynchronizationContext());   By using a continuation with a TaskScheduler based on the current synchronization context, we can keep this request asynchronous, check based on the first line of the response string, and report the results back on our UI directly.

  Read the article

• Sendmail Failing to Forward Locally Addressed Mail to Exchange Server

  - by DomainSoil

  I've recently gained employment as a web developer with a small company. What they neglected to tell me upon hire was that I would be administrating the server along with my other daily duties. Now, truth be told, I'm not clueless when it comes to these things, but this is my first rodeo working with a rack server/console.. However, I'm confident that I will be able to work through any solutions you provide. Short Description: When a customer places an order via our (Magento CE 1.8.1.0) website, a copy of said order is supposed to be BCC'd to our sales manager. I say supposed because this was a working feature before the old administrator left. Long Description: Shortly after I started, we had a server crash which required a server restart. After restart, we noticed a few features on our site weren't working, but all those have been cleaned up except this one. I had to create an account on our server for root access. When a customer places an order, our sites software (Magento CE 1.8.1.0) is configured to BCC the customers order email to our sales manager. We use a Microsoft Exchange 2007 Server for our mail, which is hosted on a different machine (in-house) that I don't have access to ATM, but I'm sure I could if needed. As far as I can tell, all other external emails work.. Only INTERNAL email addresses fail to deliver. I know this because I've also tested my own internal address via our website. I set up an account with an internal email, made a test order, and never received the email. I changed my email for the account to an external GMail account, and received emails as expected. Let's dive into the logs and config's. For privacy/security reasons, names have been changed to the following: domain.com = Our Top Level Domain. email.local = Our Exchange Server. example.com = ANY other TLD. OLDadmin = Our previous Server Administrator. NEWadmin = Me. SALES@ = Our Sales Manager. Customer# = A Customer. Here's a list of the programs and config files used that hold relevant for this issue: Server: > [root@www ~]# cat /etc/centos-release CentOS release 6.3 (final) Sendmail: > [root@www ~]# sendmail -d0.1 -bt < /dev/null Version 8.14.4 ========SYSTEM IDENTITY (after readcf)======== (short domain name) $w = domain (canonical domain name) $j = domain.com (subdomain name) $m = com (node name) $k = www.domain.com > [root@www ~]# rpm -qa | grep -i sendmail sendmail-cf-8.14.4-8.e16.noarch sendmail-8.14-4-8.e16.x86_64 nslookup: > [root@www ~]# nslookup email.local Name: email.local Address: 192.168.1.50 hostname: > [root@www ~]# hostname www.domain.com /etc/mail/access: > [root@www ~]# vi /etc/mail/access Connect:localhost.localdomain RELAY Connect:localhost RELAY Connect:127.0.0.1 RELAY /etc/mail/domaintable: > [root@www ~]# vi /etc/mail/domaintable # /etc/mail/local-host-names: > [root@www ~]# vi /etc/mail/local-host-names # /etc/mail/mailertable: > [root@www ~]# vi /etc/mail/mailertable # /etc/mail/sendmail.cf: > [root@www ~]# vi /etc/mail/sendmail.cf ###################################################################### ##### ##### DO NOT EDIT THIS FILE! Only edit the source .mc file. ##### ###################################################################### ###################################################################### ##### $Id: cfhead.m4,v 8.120 2009/01/23 22:39:21 ca Exp $ ##### ##### $Id: cf.m4,v 8.32 1999/02/07 07:26:14 gshapiro Exp $ ##### ##### setup for linux ##### ##### $Id: linux.m4,v 8.13 2000/09/17 17:30:00 gshapiro Exp $ ##### ##### $Id: local_procmail.m4,v 8.22 2002/11/17 04:24:19 ca Exp $ ##### ##### $Id: no_default_msa.m4,v 8.2 2001/02/14 05:03:22 gshapiro Exp $ ##### ##### $Id: smrsh.m4,v 8.14 1999/11/18 05:06:23 ca Exp $ ##### ##### $Id: mailertable.m4,v 8.25 2002/06/27 23:23:57 gshapiro Exp $ ##### ##### $Id: virtusertable.m4,v 8.23 2002/06/27 23:23:57 gshapiro Exp $ ##### ##### $Id: redirect.m4,v 8.15 1999/08/06 01:47:36 gshapiro Exp $ ##### ##### $Id: always_add_domain.m4,v 8.11 2000/09/12 22:00:53 ca Exp $ ##### ##### $Id: use_cw_file.m4,v 8.11 2001/08/26 20:58:57 gshapiro Exp $ ##### ##### $Id: use_ct_file.m4,v 8.11 2001/08/26 20:58:57 gshapiro Exp $ ##### ##### $Id: local_procmail.m4,v 8.22 2002/11/17 04:24:19 ca Exp $ ##### ##### $Id: access_db.m4,v 8.27 2006/07/06 21:10:10 ca Exp $ ##### ##### $Id: blacklist_recipients.m4,v 8.13 1999/04/02 02:25:13 gshapiro Exp $ ##### ##### $Id: accept_unresolvable_domains.m4,v 8.10 1999/02/07 07:26:07 gshapiro Exp $ ##### ##### $Id: masquerade_envelope.m4,v 8.9 1999/02/07 07:26:10 gshapiro Exp $ ##### ##### $Id: masquerade_entire_domain.m4,v 8.9 1999/02/07 07:26:10 gshapiro Exp $ ##### ##### $Id: proto.m4,v 8.741 2009/12/11 00:04:53 ca Exp $ ##### # level 10 config file format V10/Berkeley # override file safeties - setting this option compromises system security, # addressing the actual file configuration problem is preferred # need to set this before any file actions are encountered in the cf file #O DontBlameSendmail=safe # default LDAP map specification # need to set this now before any LDAP maps are defined #O LDAPDefaultSpec=-h localhost ################## # local info # ################## # my LDAP cluster # need to set this before any LDAP lookups are done (including classes) #D{sendmailMTACluster}$m Cwlocalhost # file containing names of hosts for which we receive email Fw/etc/mail/local-host-names # my official domain name # ... define this only if sendmail cannot automatically determine your domain #Dj$w.Foo.COM # host/domain names ending with a token in class P are canonical CP. # "Smart" relay host (may be null) DSemail.local # operators that cannot be in local usernames (i.e., network indicators) CO @ % ! # a class with just dot (for identifying canonical names) C.. # a class with just a left bracket (for identifying domain literals) C[[ # access_db acceptance class C{Accept}OK RELAY C{ResOk}OKR # Hosts for which relaying is permitted ($=R) FR-o /etc/mail/relay-domains # arithmetic map Karith arith # macro storage map Kmacro macro # possible values for TLS_connection in access map C{Tls}VERIFY ENCR # who I send unqualified names to if FEATURE(stickyhost) is used # (null means deliver locally) DRemail.local. # who gets all local email traffic # ($R has precedence for unqualified names if FEATURE(stickyhost) is used) DHemail.local. # dequoting map Kdequote dequote # class E: names that should be exposed as from this host, even if we masquerade # class L: names that should be delivered locally, even if we have a relay # class M: domains that should be converted to $M # class N: domains that should not be converted to $M #CL root C{E}root C{w}localhost.localdomain C{M}domain.com # who I masquerade as (null for no masquerading) (see also $=M) DMdomain.com # my name for error messages DnMAILER-DAEMON # Mailer table (overriding domains) Kmailertable hash -o /etc/mail/mailertable.db # Virtual user table (maps incoming users) Kvirtuser hash -o /etc/mail/virtusertable.db CPREDIRECT # Access list database (for spam stomping) Kaccess hash -T<TMPF> -o /etc/mail/access.db # Configuration version number DZ8.14.4 /etc/mail/sendmail.mc: > [root@www ~]# vi /etc/mail/sendmail.mc divert(-1)dnl dnl # dnl # This is the sendmail macro config file for m4. If you make changes to dnl # /etc/mail/sendmail.mc, you will need to regenerate the dnl # /etc/mail/sendmail.cf file by confirming that the sendmail-cf package is dnl # installed and then performing a dnl # dnl # /etc/mail/make dnl # include(`/usr/share/sendmail-cf/m4/cf.m4')dnl VERSIONID(`setup for linux')dnl OSTYPE(`linux')dnl dnl # dnl # Do not advertize sendmail version. dnl # dnl define(`confSMTP_LOGIN_MSG', `$j Sendmail; $b')dnl dnl # dnl # default logging level is 9, you might want to set it higher to dnl # debug the configuration dnl # dnl define(`confLOG_LEVEL', `9')dnl dnl # dnl # Uncomment and edit the following line if your outgoing mail needs to dnl # be sent out through an external mail server: dnl # define(`SMART_HOST', `email.local')dnl dnl # define(`confDEF_USER_ID', ``8:12'')dnl dnl define(`confAUTO_REBUILD')dnl define(`confTO_CONNECT', `1m')dnl define(`confTRY_NULL_MX_LIST', `True')dnl define(`confDONT_PROBE_INTERFACES', `True')dnl define(`PROCMAIL_MAILER_PATH', `/usr/bin/procmail')dnl define(`ALIAS_FILE', `/etc/aliases')dnl define(`STATUS_FILE', `/var/log/mail/statistics')dnl define(`UUCP_MAILER_MAX', `2000000')dnl define(`confUSERDB_SPEC', `/etc/mail/userdb.db')dnl define(`confPRIVACY_FLAGS', `authwarnings,novrfy,noexpn,restrictqrun')dnl define(`confAUTH_OPTIONS', `A')dnl dnl # dnl # The following allows relaying if the user authenticates, and disallows dnl # plaintext authentication (PLAIN/LOGIN) on non-TLS links dnl # dnl define(`confAUTH_OPTIONS', `A p')dnl dnl # dnl # PLAIN is the preferred plaintext authentication method and used by dnl # Mozilla Mail and Evolution, though Outlook Express and other MUAs do dnl # use LOGIN. Other mechanisms should be used if the connection is not dnl # guaranteed secure. dnl # Please remember that saslauthd needs to be running for AUTH. dnl # dnl TRUST_AUTH_MECH(`EXTERNAL DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl dnl define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl dnl # dnl # Rudimentary information on creating certificates for sendmail TLS: dnl # cd /etc/pki/tls/certs; make sendmail.pem dnl # Complete usage: dnl # make -C /etc/pki/tls/certs usage dnl # dnl define(`confCACERT_PATH', `/etc/pki/tls/certs')dnl dnl define(`confCACERT', `/etc/pki/tls/certs/ca-bundle.crt')dnl dnl define(`confSERVER_CERT', `/etc/pki/tls/certs/sendmail.pem')dnl dnl define(`confSERVER_KEY', `/etc/pki/tls/certs/sendmail.pem')dnl dnl # dnl # This allows sendmail to use a keyfile that is shared with OpenLDAP's dnl # slapd, which requires the file to be readble by group ldap dnl # dnl define(`confDONT_BLAME_SENDMAIL', `groupreadablekeyfile')dnl dnl # dnl define(`confTO_QUEUEWARN', `4h')dnl dnl define(`confTO_QUEUERETURN', `5d')dnl dnl define(`confQUEUE_LA', `12')dnl dnl define(`confREFUSE_LA', `18')dnl define(`confTO_IDENT', `0')dnl dnl FEATURE(delay_checks)dnl FEATURE(`no_default_msa', `dnl')dnl FEATURE(`smrsh', `/usr/sbin/smrsh')dnl FEATURE(`mailertable', `hash -o /etc/mail/mailertable.db')dnl FEATURE(`virtusertable', `hash -o /etc/mail/virtusertable.db')dnl FEATURE(redirect)dnl FEATURE(always_add_domain)dnl FEATURE(use_cw_file)dnl FEATURE(use_ct_file)dnl dnl # dnl # The following limits the number of processes sendmail can fork to accept dnl # incoming messages or process its message queues to 20.) sendmail refuses dnl # to accept connections once it has reached its quota of child processes. dnl # dnl define(`confMAX_DAEMON_CHILDREN', `20')dnl dnl # dnl # Limits the number of new connections per second. This caps the overhead dnl # incurred due to forking new sendmail processes. May be useful against dnl # DoS attacks or barrages of spam. (As mentioned below, a per-IP address dnl # limit would be useful but is not available as an option at this writing.) dnl # dnl define(`confCONNECTION_RATE_THROTTLE', `3')dnl dnl # dnl # The -t option will retry delivery if e.g. the user runs over his quota. dnl # FEATURE(local_procmail, `', `procmail -t -Y -a $h -d $u')dnl FEATURE(`access_db', `hash -T<TMPF> -o /etc/mail/access.db')dnl FEATURE(`blacklist_recipients')dnl EXPOSED_USER(`root')dnl dnl # dnl # For using Cyrus-IMAPd as POP3/IMAP server through LMTP delivery uncomment dnl # the following 2 definitions and activate below in the MAILER section the dnl # cyrusv2 mailer. dnl # dnl define(`confLOCAL_MAILER', `cyrusv2')dnl dnl define(`CYRUSV2_MAILER_ARGS', `FILE /var/lib/imap/socket/lmtp')dnl dnl # dnl # The following causes sendmail to only listen on the IPv4 loopback address dnl # 127.0.0.1 and not on any other network devices. Remove the loopback dnl # address restriction to accept email from the internet or intranet. dnl # DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl dnl # dnl # The following causes sendmail to additionally listen to port 587 for dnl # mail from MUAs that authenticate. Roaming users who can't reach their dnl # preferred sendmail daemon due to port 25 being blocked or redirected find dnl # this useful. dnl # dnl DAEMON_OPTIONS(`Port=submission, Name=MSA, M=Ea')dnl dnl # dnl # The following causes sendmail to additionally listen to port 465, but dnl # starting immediately in TLS mode upon connecting. Port 25 or 587 followed dnl # by STARTTLS is preferred, but roaming clients using Outlook Express can't dnl # do STARTTLS on ports other than 25. Mozilla Mail can ONLY use STARTTLS dnl # and doesn't support the deprecated smtps; Evolution <1.1.1 uses smtps dnl # when SSL is enabled-- STARTTLS support is available in version 1.1.1. dnl # dnl # For this to work your OpenSSL certificates must be configured. dnl # dnl DAEMON_OPTIONS(`Port=smtps, Name=TLSMTA, M=s')dnl dnl # dnl # The following causes sendmail to additionally listen on the IPv6 loopback dnl # device. Remove the loopback address restriction listen to the network. dnl # dnl DAEMON_OPTIONS(`port=smtp,Addr=::1, Name=MTA-v6, Family=inet6')dnl dnl # dnl # enable both ipv6 and ipv4 in sendmail: dnl # dnl DAEMON_OPTIONS(`Name=MTA-v4, Family=inet, Name=MTA-v6, Family=inet6') dnl # dnl # We strongly recommend not accepting unresolvable domains if you want to dnl # protect yourself from spam. However, the laptop and users on computers dnl # that do not have 24x7 DNS do need this. dnl # FEATURE(`accept_unresolvable_domains')dnl dnl # dnl FEATURE(`relay_based_on_MX')dnl dnl # dnl # Also accept email sent to "localhost.localdomain" as local email. dnl # LOCAL_DOMAIN(`localhost.localdomain')dnl dnl # dnl # The following example makes mail from this host and any additional dnl # specified domains appear to be sent from mydomain.com dnl # MASQUERADE_AS(`domain.com')dnl dnl # dnl # masquerade not just the headers, but the envelope as well dnl FEATURE(masquerade_envelope)dnl dnl # dnl # masquerade not just @mydomainalias.com, but @*.mydomainalias.com as well dnl # FEATURE(masquerade_entire_domain)dnl dnl # MASQUERADE_DOMAIN(domain.com)dnl dnl MASQUERADE_DOMAIN(localhost.localdomain)dnl dnl MASQUERADE_DOMAIN(mydomainalias.com)dnl dnl MASQUERADE_DOMAIN(mydomain.lan)dnl MAILER(smtp)dnl MAILER(procmail)dnl dnl MAILER(cyrusv2)dnl /etc/mail/trusted-users: > [root@www ~]# vi /etc/mail/trusted-users # /etc/mail/virtusertable: > [root@www ~]# vi /etc/mail/virtusertable [email protected] [email protected] [email protected] [email protected] /etc/hosts: > [root@www ~]# vi /etc/hosts 127.0.0.1 localhost.localdomain localhost ::1 localhost6.localdomain6 localhost6 192.168.1.50 email.local I've only included the "local info" part of sendmail.cf, to save space. If there are any files that I've missed, please advise so I may produce them. Now that that's out of the way, lets look at some entries from /var/log/maillog. The first entry is from an order BEFORE the crash, when the site was working as expected. ##Order 200005374 Aug 5, 2014 7:06:38 AM## Aug 5 07:06:39 www sendmail[26149]: s75C6dqB026149: from=OLDadmin, size=11091, class=0, nrcpts=2, msgid=<[email protected]>, relay=OLDadmin@localhost Aug 5 07:06:39 www sendmail[26150]: s75C6dXe026150: from=<[email protected]>, size=11257, class=0, nrcpts=2, msgid=<[email protected]>, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1] Aug 5 07:06:39 www sendmail[26149]: s75C6dqB026149: [email protected],=?utf-8?B?dGhvbWFzICBHaWxsZXNwaWU=?= <[email protected]>, ctladdr=OLDadmin (501/501), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=71091, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (s75C6dXe026150 Message accepted for delivery) Aug 5 07:06:40 www sendmail[26152]: s75C6dXe026150: to=<[email protected]>,<[email protected]>, delay=00:00:01, xdelay=00:00:01, mailer=relay, pri=161257, relay=email.local. [192.168.1.50], dsn=2.0.0, stat=Sent ( <[email protected]> Queued mail for delivery) This next entry from maillog is from an order AFTER the crash. ##Order 200005375 Aug 5, 2014 9:45:25 AM## Aug 5 09:45:26 www sendmail[30021]: s75EjQ4O030021: from=OLDadmin, size=11344, class=0, nrcpts=2, msgid=<[email protected]>, relay=OLDadmin@localhost Aug 5 09:45:26 www sendmail[30022]: s75EjQm1030022: <[email protected]>... User unknown Aug 5 09:45:26 www sendmail[30021]: s75EjQ4O030021: [email protected], ctladdr=OLDadmin (501/501), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=71344, relay=[127.0.0.1] [127.0.0.1], dsn=5.1.1, stat=User unknown Aug 5 09:45:26 www sendmail[30022]: s75EjQm1030022: from=<[email protected]>, size=11500, class=0, nrcpts=1, msgid=<[email protected]>, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1] Aug 5 09:45:26 www sendmail[30021]: s75EjQ4O030021: to==?utf-8?B?S2VubmV0aCBCaWViZXI=?= <[email protected]>, ctladdr=OLDadmin (501/501), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=71344, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (s75EjQm1030022 Message accepted for delivery) Aug 5 09:45:26 www sendmail[30021]: s75EjQ4O030021: s75EjQ4P030021: DSN: User unknown Aug 5 09:45:26 www sendmail[30022]: s75EjQm3030022: <[email protected]>... User unknown Aug 5 09:45:26 www sendmail[30021]: s75EjQ4P030021: to=OLDadmin, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=42368, relay=[127.0.0.1] [127.0.0.1], dsn=5.1.1, stat=User unknown Aug 5 09:45:26 www sendmail[30022]: s75EjQm3030022: from=<>, size=12368, class=0, nrcpts=0, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1] Aug 5 09:45:26 www sendmail[30021]: s75EjQ4P030021: s75EjQ4Q030021: return to sender: User unknown Aug 5 09:45:26 www sendmail[30022]: s75EjQm5030022: from=<>, size=14845, class=0, nrcpts=1, msgid=<[email protected]>, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1] Aug 5 09:45:26 www sendmail[30021]: s75EjQ4Q030021: to=postmaster, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=43392, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (s75EjQm5030022 Message accepted for delivery) Aug 5 09:45:26 www sendmail[30025]: s75EjQm5030022: to=root, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=45053, dsn=2.0.0, stat=Sent Aug 5 09:45:27 www sendmail[30024]: s75EjQm1030022: to=<[email protected]>, delay=00:00:01, xdelay=00:00:01, mailer=relay, pri=131500, relay=email.local. [192.168.1.50], dsn=2.0.0, stat=Sent ( <[email protected]> Queued mail for delivery) To add a little more, I think I've pinpointed the actual crash event. ##THE CRASH## Aug 5 09:39:46 www sendmail[3251]: restarting /usr/sbin/sendmail due to signal Aug 5 09:39:46 www sm-msp-queue[3260]: restarting /usr/sbin/sendmail due to signal Aug 5 09:39:46 www sm-msp-queue[29370]: starting daemon (8.14.4): queueing@01:00:00 Aug 5 09:39:47 www sendmail[29372]: starting daemon (8.14.4): SMTP+queueing@01:00:00 Aug 5 09:40:02 www sendmail[29465]: s75Ee2vT029465: Authentication-Warning: www.domain.com: OLDadmin set sender to root using -f Aug 5 09:40:02 www sendmail[29464]: s75Ee2IF029464: Authentication-Warning: www.domain.com: OLDadmin set sender to root using -f Aug 5 09:40:02 www sendmail[29465]: s75Ee2vT029465: from=root, size=1426, class=0, nrcpts=1, msgid=<[email protected]>, relay=OLDadmin@localhost Aug 5 09:40:02 www sendmail[29464]: s75Ee2IF029464: from=root, size=1426, class=0, nrcpts=1, msgid=<[email protected]>, relay=OLDadmin@localhost Aug 5 09:40:02 www sendmail[29466]: s75Ee23t029466: from=<[email protected]>, size=1784, class=0, nrcpts=1, msgid=<[email protected]>, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1] Aug 5 09:40:02 www sendmail[29466]: s75Ee23t029466: to=<[email protected]>, delay=00:00:00, mailer=local, pri=31784, dsn=4.4.3, stat=queued Aug 5 09:40:02 www sendmail[29467]: s75Ee2wh029467: from=<[email protected]>, size=1784, class=0, nrcpts=1, msgid=<[email protected]>, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1] Aug 5 09:40:02 www sendmail[29467]: s75Ee2wh029467: to=<[email protected]>, delay=00:00:00, mailer=local, pri=31784, dsn=4.4.3, stat=queued Aug 5 09:40:02 www sendmail[29464]: s75Ee2IF029464: to=OLDadmin, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=31426, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (s75Ee23t029466 Message accepted for delivery) Aug 5 09:40:02 www sendmail[29465]: s75Ee2vT029465: to=OLDadmin, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=31426, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (s75Ee2wh029467 Message accepted for delivery) Aug 5 09:40:06 www sm-msp-queue[29370]: restarting /usr/sbin/sendmail due to signal Aug 5 09:40:06 www sendmail[29372]: restarting /usr/sbin/sendmail due to signal Aug 5 09:40:06 www sm-msp-queue[29888]: starting daemon (8.14.4): queueing@01:00:00 Aug 5 09:40:06 www sendmail[29890]: starting daemon (8.14.4): SMTP+queueing@01:00:00 Aug 5 09:40:06 www sendmail[29891]: s75Ee23t029466: to=<[email protected]>, delay=00:00:04, mailer=local, pri=121784, dsn=5.1.1, stat=User unknown Aug 5 09:40:06 www sendmail[29891]: s75Ee23t029466: s75Ee6xY029891: DSN: User unknown Aug 5 09:40:06 www sendmail[29891]: s75Ee6xY029891: to=<[email protected]>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=33035, dsn=2.0.0, stat=Sent Aug 5 09:40:06 www sendmail[29891]: s75Ee2wh029467: to=<[email protected]>, delay=00:00:04, mailer=local, pri=121784, dsn=5.1.1, stat=User unknown Aug 5 09:40:06 www sendmail[29891]: s75Ee2wh029467: s75Ee6xZ029891: DSN: User unknown Aug 5 09:40:06 www sendmail[29891]: s75Ee6xZ029891: to=<[email protected]>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=33035, dsn=2.0.0, stat=Sent Something to note about the maillog's: Before the crash, the msgid included localhost.localdomain; after the crash it's been domain.com. Thanks to all who take the time to read and look into this issue. I appreciate it and look forward to tackling this issue together.

  Read the article

• Messages don’t always appear in Mail.app

  - by MikeHoss

  I asked this question on serverfault, but it was correctly suggested that superuser is better -- and I agree: My wife and I share a Mac and use different accounts. We both use Apple's standard Mail.app. We can also get to our email accounts via SquirrelMail that our webhost provides. Both SquirrelMail and Mail.app are connecting via IMAP. My wife was the first to notice that not all messages were getting to the Mail.app. She would check the Mac (our main machine) and then a little while later check mail from another machine via SquirrelMail and see messages there that should have been on the Mac. She would go back and those messages would never show up. Lately, I have been seeing the same thing, though less often. I can't reproduce it, or just look at a message to see if they haven't been moved over. I've looked in Junk, etc. and the Mac simply never sees those messages via IMAP. Does anyone have a guess to something I could poke around at?

  Read the article

• Testing a method that sends e-mail without sending the mail

  - by SnOrfus

  I have a method like public abstract class Base { public void MethodUnderTest(); } public class ClassUnderTest : Base { public override MethodUnderTest() { if(condition) { IMail mail = new Mail() { /* ... */ }; IMailer mailer = new Mailer() { /* ... */ } mailer.Send(mail); } else { /* ... */ } } } I have unit tests for this method, and the mail gets sent to myself, so it's not terrible (better than no test) but I'd prefer not to send the mail. The problem I have is that I don't want test specific code in the class (ie. if (testMode) return; instead of sending the mail) I don't know lots about DI, but I considered passing a mock IMailer into MethodUnderTest except that it overrides the base class, and no other class that derives from Base needs an IMailer object (I don't want to force implementers of Base to take an unnecessary IMailer in MethodUnderTest) What else can I do? (note: IMail and IMailer are part of an external library for sending e-mail. It's written in house, so I can modify it all I like if necessary, though I can't see a need to in this situation)

  Read the article

• Parallelism in .NET – Part 1, Decomposition

  - by Reed

  The first step in designing any parallelized system is Decomposition.  Decomposition is nothing more than taking a problem space and breaking it into discrete parts.  When we want to work in parallel, we need to have at least two separate things that we are trying to run.  We do this by taking our problem and decomposing it into parts. There are two common abstractions that are useful when discussing parallel decomposition: Data Decomposition and Task Decomposition.  These two abstractions allow us to think about our problem in a way that helps leads us to correct decision making in terms of the algorithms we’ll use to parallelize our routine. To start, I will make a couple of minor points. I’d like to stress that Decomposition has nothing to do with specific algorithms or techniques.  It’s about how you approach and think about the problem, not how you solve the problem using a specific tool, technique, or library.  Decomposing the problem is about constructing the appropriate mental model: once this is done, you can choose the appropriate design and tools, which is a subject for future posts. Decomposition, being unrelated to tools or specific techniques, is not specific to .NET in any way.  This should be the first step to parallelizing a problem, and is valid using any framework, language, or toolset.  However, this gives us a starting point – without a proper understanding of decomposition, it is difficult to understand the proper usage of specific classes and tools within the .NET framework. Data Decomposition is often the simpler abstraction to use when trying to parallelize a routine.  In order to decompose our problem domain by data, we take our entire set of data and break it into smaller, discrete portions, or chunks.  We then work on each chunk in the data set in parallel. This is particularly useful if we can process each element of data independently of the rest of the data.  In a situation like this, there are some wonderfully simple techniques we can use to take advantage of our data.  By decomposing our domain by data, we can very simply parallelize our routines.  In general, we, as developers, should be always searching for data that can be decomposed. Finding data to decompose if fairly simple, in many instances.  Data decomposition is typically used with collections of data.  Any time you have a collection of items, and you’re going to perform work on or with each of the items, you potentially have a situation where parallelism can be exploited.  This is fairly easy to do in practice: look for iteration statements in your code, such as for and foreach. Granted, every for loop is not a candidate to be parallelized.  If the collection is being modified as it’s iterated, or the processing of elements depends on other elements, the iteration block may need to be processed in serial.  However, if this is not the case, data decomposition may be possible. Let’s look at one example of how we might use data decomposition.  Suppose we were working with an image, and we were applying a simple contrast stretching filter.  When we go to apply the filter, once we know the minimum and maximum values, we can apply this to each pixel independently of the other pixels.  This means that we can easily decompose this problem based off data – we will do the same operation, in parallel, on individual chunks of data (each pixel). Task Decomposition, on the other hand, is focused on the individual tasks that need to be performed instead of focusing on the data.  In order to decompose our problem domain by tasks, we need to think about our algorithm in terms of discrete operations, or tasks, which can then later be parallelized. Task decomposition, in practice, can be a bit more tricky than data decomposition.  Here, we need to look at what our algorithm actually does, and how it performs its actions.  Once we have all of the basic steps taken into account, we can try to analyze them and determine whether there are any constraints in terms of shared data or ordering.  There are no simple things to look for in terms of finding tasks we can decompose for parallelism; every algorithm is unique in terms of its tasks, so every algorithm will have unique opportunities for task decomposition. For example, say we want our software to perform some customized actions on startup, prior to showing our main screen.  Perhaps we want to check for proper licensing, notify the user if the license is not valid, and also check for updates to the program.  Once we verify the license, and that there are no updates, we’ll start normally.  In this case, we can decompose this problem into tasks – we have a few tasks, but there are at least two discrete, independent tasks (check licensing, check for updates) which we can perform in parallel.  Once those are completed, we will continue on with our other tasks. One final note – Data Decomposition and Task Decomposition are not mutually exclusive.  Often, you’ll mix the two approaches while trying to parallelize a single routine.  It’s possible to decompose your problem based off data, then further decompose the processing of each element of data based on tasks.  This just provides a framework for thinking about our algorithms, and for discussing the problem.

  Read the article

• Optional Parameters and Named Arguments in C# 4 (and a cool scenario w/ ASP.NET MVC 2)

  - by ScottGu

  [In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu] This is the seventeenth in a series of blog posts I’m doing on the upcoming VS 2010 and .NET 4 release. Today’s post covers two new language feature being added to C# 4.0 – optional parameters and named arguments – as well as a cool way you can take advantage of optional parameters (both in VB and C#) with ASP.NET MVC 2. Optional Parameters in C# 4.0 C# 4.0 now supports using optional parameters with methods, constructors, and indexers (note: VB has supported optional parameters for awhile). Parameters are optional when a default value is specified as part of a declaration.  For example, the method below takes two parameters – a “category” string parameter, and a “pageIndex” integer parameter.  The “pageIndex” parameter has a default value of 0, and as such is an optional parameter: When calling the above method we can explicitly pass two parameters to it: Or we can omit passing the second optional parameter – in which case the default value of 0 will be passed:   Note that VS 2010’s Intellisense indicates when a parameter is optional, as well as what its default value is when statement completion is displayed: Named Arguments and Optional Parameters in C# 4.0 C# 4.0 also now supports the concept of “named arguments”.  This allows you to explicitly name an argument you are passing to a method – instead of just identifying it by argument position.  For example, I could write the code below to explicitly identify the second argument passed to the GetProductsByCategory method by name (making its usage a little more explicit): Named arguments come in very useful when a method supports multiple optional parameters, and you want to specify which arguments you are passing.  For example, below we have a method DoSomething that takes two optional parameters: We could use named arguments to call the above method in any of the below ways: Because both parameters are optional, in cases where only one (or zero) parameters is specified then the default value for any non-specified arguments is passed. ASP.NET MVC 2 and Optional Parameters One nice usage scenario where we can now take advantage of the optional parameter support of VB and C# is with ASP.NET MVC 2’s input binding support to Action methods on Controller classes. For example, consider a scenario where we want to map URLs like “Products/Browse/Beverages” or “Products/Browse/Deserts” to a controller action method.  We could do this by writing a URL routing rule that maps the URLs to a method like so: We could then optionally use a “page” querystring value to indicate whether or not the results displayed by the Browse method should be paged – and if so which page of the results should be displayed.  For example: /Products/Browse/Beverages?page=2. With ASP.NET MVC 1 you would typically handle this scenario by adding a “page” parameter to the action method and make it a nullable int (which means it will be null if the “page” querystring value is not present).  You could then write code like below to convert the nullable int to an int – and assign it a default value if it was not present in the querystring: With ASP.NET MVC 2 you can now take advantage of the optional parameter support in VB and C# to express this behavior more concisely and clearly.  Simply declare the action method parameter as an optional parameter with a default value: C# VB If the “page” value is present in the querystring (e.g. /Products/Browse/Beverages?page=22) then it will be passed to the action method as an integer.  If the “page” value is not in the querystring (e.g. /Products/Browse/Beverages) then the default value of 0 will be passed to the action method.  This makes the code a little more concise and readable. Summary There are a bunch of great new language features coming to both C# and VB with VS 2010.  The above two features (optional parameters and named parameters) are but two of them.  I’ll blog about more in the weeks and months ahead. If you are looking for a good book that summarizes all the language features in C# (including C# 4.0), as well provides a nice summary of the core .NET class libraries, you might also want to check out the newly released C# 4.0 in a Nutshell book from O’Reilly: It does a very nice job of packing a lot of content in an easy to search and find samples format. Hope this helps, Scott

  Read the article

• IE9 RC fixed the “Internet Explorer cannot display the webpage” error when running an ASP.NET application in Visual Studio

  - by Jon Galloway

  One of the obstacles ASP.NET developers faced in using the Internet Explorer 9 Beta was the dreaded “Internet Explorer cannot display the webpage” error when running an ASP.NET application in Visual Studio. In the bug information on Connect (issue 601047), Eric Lawrence said that the problem was due to “caused by failure to failover from IPv6 to IPv4 when the connection is local.” Robert MacLean gives some more information as what was going wrong: “The problem is Windows, especially since it assumes IPv6 is better than IPv4. Note […] that when you ping localhost you get an IPv6 address. So what appears to be happening is when IE9 tries to go to localhost it uses IPv6, and the ASP.NET Development Server is IPv4 only and so nothing loads and we get the error.” The Simple Fix - Install IE 9 RC Internet Explorer 9 RC fixes this bug, so if you had tried IE 9 Beta and stopped using it due to problems with ASP.NET development, install the RC. The Workaround in IE 9 Beta If you're stuck on IE 9 Beta for some reason, you can follow Robert's workaround, which involves a one character edit to your hosts file. I've been using it for months, and it works great. Open notepad (running as administrator) and edit the hosts file (found in %systemroot%\system32\drivers\etc) Remove the # comment character before the line starting with 127.0.0.1 Save the file - if you have problems saving, it's probably because you weren't running as administrator When you're done, your hosts file will end with the following lines (assuming you were using a default hosts file setup beforehand): # localhost name resolution is handled within DNS itself.     127.0.0.1       localhost #    ::1             localhost Note: more information on editing your hosts file here. This causes Windows to default to IPv4 when resolving localhost, which will point to 127.0.0.1, which is right where Cassini - I mean the ASP.NET Web Development Server - is waiting for it.

  Read the article

• Deploying ASP.NET Web Applications

  - by Ben Griswold

  In this episode, Noah and I explain how to use Web Deployment Projects to deploy your web application. This screencast will get you up and running, but in a future screencast, we discuss more advanced topics like excluding files, swapping out the right config files per environment, and alternate solution configurations.  This screencast (and the next) are based on a write-up I did about ASP.NET Web Application deployment with Web Deployment Projects a while back.  Multi-media knowledge sharing.  You have to love it! This is the first video hosted on Vimeo.  What do you think?

  Read the article

• System Center Essential autoloader support

  - by Jedi Master Spooky

  Does System Center Essential support the HP Autoloader 1/8 LTO4 1760?

  Read the article

• Object-Oriented Operating System

  - by nmagerko

  As I thought about writing an operating system, I came across a point that I really couldn't figure out on my own: Can an operating system truly be written in an Object-Oriented Programming (OOP) Language? Being that these types of languages do not allow for direct accessing of memory, wouldn't this make it impossible for a developer to write an entire operating system using only an OOP Language? Take, for example, the Android Operating System that runs many phones and some tablets in use around the world. I believe that this operating system uses only Java, an Object-Oriented language. In Java, I have been unsuccessful in trying to point at and manipulate a specific memory address that the run-time environment (JRE) has not assigned to my program implicitly. In C, C++, and other non-OOP languages, I can do this in a few lines. So this makes me question whether or not an operating system can be written in an OOP, especially Java. Any counterexamples or other information is appreciated.

  Read the article

• JavaEE : "Access to default session denied" when sending mail using smtp.gmail.com

  - by Harry Pham

  I am trying to write email authentication feature for my website and I encounter some issues. I got java.lang.SecurityException: Access to default session denied, when I try to do Session.getDefaultInstance. Here are my codes: private static final String SMTP_HOST_NAME = "smtp.gmail.com"; private static final String SMTP_PORT = "465"; private static final String emailSubjectTxt = "Email Confirmation"; private static final String emailFromAddress = "[email protected]"; private static final String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory"; ... String sendTo = "[email protected]"; boolean debug = true; Properties props = new Properties(); props.put("mail.smtp.host", SMTP_HOST_NAME); props.put("mail.smtp.auth", "true"); props.put("mail.debug", "true"); props.put("mail.smtp.port", SMTP_PORT); props.put("mail.smtp.socketFactory.port", SMTP_PORT); props.put("mail.smtp.socketFactory.class", SSL_FACTORY); props.put("mail.smtp.socketFactory.fallback", "false"); //It dies at the next line Session session = Session.getDefaultInstance(props, new javax.mail.Authenticator() { @Override protected PasswordAuthentication getPasswordAuthentication() { return new PasswordAuthentication("myUserName", "myPassword"); } }); session.setDebug(debug); //Set the FROM address Message msg = new MimeMessage(session); InternetAddress addressFrom = new InternetAddress(emailFromAddress); msg.setFrom(addressFrom); //Set the TO address InternetAddress[] addressTo = new InternetAddress[1]; addressTo[0] = new InternetAddress(sendTo); msg.setRecipients(Message.RecipientType.TO, addressTo); //Construct the content of the email confirmation String message = "Test Content" // Setting the Subject and Content Type msg.setSubject(emailSubjectTxt); msg.setContent(message, "text/plain"); Transport.send(msg);

  Read the article

• .NET: Interface Problem VB.net Getter Only Interface

  - by snmcdonald

  Why does an interface override a class definition and violate class encapsulation? I have included two samples below, one in C# and one in VB.net? VB.net Module Module1 Sub Main() Dim testInterface As ITest = New TestMe Console.WriteLine(testInterface.Testable) ''// Prints False testInterface.Testable = True ''// Access to Private!!! Console.WriteLine(testInterface.Testable) ''// Prints True Dim testClass As TestMe = New TestMe Console.WriteLine(testClass.Testable) ''// Prints False ''//testClass.Testable = True ''// Compile Error Console.WriteLine(testClass.Testable) ''// Prints False End Sub End Module Public Class TestMe : Implements ITest Private m_testable As Boolean = False Public Property Testable As Boolean Implements ITest.Testable Get Return m_testable End Get Private Set(ByVal value As Boolean) m_testable = value End Set End Property End Class Interface ITest Property Testable As Boolean End Interface C# using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace InterfaceCSTest { class Program { static void Main(string[] args) { ITest testInterface = new TestMe(); Console.WriteLine(testInterface.Testable); testInterface.Testable = true; Console.WriteLine(testInterface.Testable); TestMe testClass = new TestMe(); Console.WriteLine(testClass.Testable); //testClass.Testable = true; Console.WriteLine(testClass.Testable); } } class TestMe : ITest { private bool m_testable = false; public bool Testable { get { return m_testable; } private set { m_testable = value; } } } interface ITest { bool Testable { get; set; } } } More Specifically How do I implement a interface in VB.net that will allow for a private setter. For example in C# I can declare: class TestMe : ITest { private bool m_testable = false; public bool Testable { get { return m_testable; } private set //No Compile Error here! { m_testable = value; } } } interface ITest { bool Testable { get; } } However, if I declare an interface property as readonly in VB.net I cannot create a setter. If I create a VB.net interface as just a plain old property then interface declarations will violate my encapsulation. Public Class TestMe : Implements ITest Private m_testable As Boolean = False Public ReadOnly Property Testable As Boolean Implements ITest.Testable Get Return m_testable End Get Private Set(ByVal value As Boolean) ''//Compile Error m_testable = value End Set End Property End Class Interface ITest ReadOnly Property Testable As Boolean End Interface So my question is, how do I define a getter only Interface in VB.net with proper encapsulation? I figured the first example would have been the best method. However, it appears as if interface definitions overrule class definitions. So I tried to create a getter only (Readonly) property like in C# but it does not work for VB.net. Maybe this is just a limitation of the language?

  Read the article

• Parallelism in .NET – Part 10, Cancellation in PLINQ and the Parallel class

  - by Reed

  Many routines are parallelized because they are long running processes.  When writing an algorithm that will run for a long period of time, its typically a good practice to allow that routine to be cancelled.  I previously discussed terminating a parallel loop from within, but have not demonstrated how a routine can be cancelled from the caller’s perspective.  Cancellation in PLINQ and the Task Parallel Library is handled through a new, unified cooperative cancellation model introduced with .NET 4.0. Cancellation in .NET 4 is based around a new, lightweight struct called CancellationToken.  A CancellationToken is a small, thread-safe value type which is generated via a CancellationTokenSource.  There are many goals which led to this design.  For our purposes, we will focus on a couple of specific design decisions: Cancellation is cooperative.  A calling method can request a cancellation, but it’s up to the processing routine to terminate – it is not forced. Cancellation is consistent.  A single method call requests a cancellation on every copied CancellationToken in the routine. Let’s begin by looking at how we can cancel a PLINQ query.  Supposed we wanted to provide the option to cancel our query from Part 6: double min = collection .AsParallel() .Min(item => item.PerformComputation()); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } We would rewrite this to allow for cancellation by adding a call to ParallelEnumerable.WithCancellation as follows: var cts = new CancellationTokenSource(); // Pass cts here to a routine that could, // in parallel, request a cancellation try { double min = collection .AsParallel() .WithCancellation(cts.Token) .Min(item => item.PerformComputation()); } catch (OperationCanceledException e) { // Query was cancelled before it finished } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here, if the user calls cts.Cancel() before the PLINQ query completes, the query will stop processing, and an OperationCanceledException will be raised.  Be aware, however, that cancellation will not be instantaneous.  When cts.Cancel() is called, the query will only stop after the current item.PerformComputation() elements all finish processing.  cts.Cancel() will prevent PLINQ from scheduling a new task for a new element, but will not stop items which are currently being processed.  This goes back to the first goal I mentioned – Cancellation is cooperative.  Here, we’re requesting the cancellation, but it’s up to PLINQ to terminate. If we wanted to allow cancellation to occur within our routine, we would need to change our routine to accept a CancellationToken, and modify it to handle this specific case: public void PerformComputation(CancellationToken token) { for (int i=0; i<this.iterations; ++i) { // Add a check to see if we've been canceled // If a cancel was requested, we'll throw here token.ThrowIfCancellationRequested(); // Do our processing now this.RunIteration(i); } } With this overload of PerformComputation, each internal iteration checks to see if a cancellation request was made, and will throw an OperationCanceledException at that point, instead of waiting until the method returns.  This is good, since it allows us, as developers, to plan for cancellation, and terminate our routine in a clean, safe state. This is handled by changing our PLINQ query to: try { double min = collection .AsParallel() .WithCancellation(cts.Token) .Min(item => item.PerformComputation(cts.Token)); } catch (OperationCanceledException e) { // Query was cancelled before it finished } PLINQ is very good about handling this exception, as well.  There is a very good chance that multiple items will raise this exception, since the entire purpose of PLINQ is to have multiple items be processed concurrently.  PLINQ will take all of the OperationCanceledException instances raised within these methods, and merge them into a single OperationCanceledException in the call stack.  This is done internally because we added the call to ParallelEnumerable.WithCancellation. If, however, a different exception is raised by any of the elements, the OperationCanceledException as well as the other Exception will be merged into a single AggregateException. The Task Parallel Library uses the same cancellation model, as well.  Here, we supply our CancellationToken as part of the configuration.  The ParallelOptions class contains a property for the CancellationToken.  This allows us to cancel a Parallel.For or Parallel.ForEach routine in a very similar manner to our PLINQ query.  As an example, we could rewrite our Parallel.ForEach loop from Part 2 to support cancellation by changing it to: try { var cts = new CancellationTokenSource(); var options = new ParallelOptions() { CancellationToken = cts.Token }; Parallel.ForEach(customers, options, customer => { // Run some process that takes some time... DateTime lastContact = theStore.GetLastContact(customer); TimeSpan timeSinceContact = DateTime.Now - lastContact; // Check for cancellation here options.CancellationToken.ThrowIfCancellationRequested(); // If it's been more than two weeks, send an email, and update... if (timeSinceContact.Days > 14) { theStore.EmailCustomer(customer); customer.LastEmailContact = DateTime.Now; } }); } catch (OperationCanceledException e) { // The loop was cancelled } Notice that here we use the same approach taken in PLINQ.  The Task Parallel Library will automatically handle our cancellation in the same manner as PLINQ, providing a clean, unified model for cancellation of any parallel routine.  The TPL performs the same aggregation of the cancellation exceptions as PLINQ, as well, which is why a single exception handler for OperationCanceledException will cleanly handle this scenario.  This works because we’re using the same CancellationToken provided in the ParallelOptions.  If a different exception was thrown by one thread, or a CancellationToken from a different CancellationTokenSource was used to raise our exception, we would instead receive all of our individual exceptions merged into one AggregateException.

  Read the article

• Parallelism in .NET – Part 15, Making Tasks Run: The TaskScheduler

  - by Reed

  In my introduction to the Task class, I specifically made mention that the Task class does not directly provide it’s own execution.  In addition, I made a strong point that the Task class itself is not directly related to threads or multithreading.  Rather, the Task class is used to implement our decomposition of tasks.  Once we’ve implemented our tasks, we need to execute them.  In the Task Parallel Library, the execution of Tasks is handled via an instance of the TaskScheduler class. The TaskScheduler class is an abstract class which provides a single function: it schedules the tasks and executes them within an appropriate context.  This class is the class which actually runs individual Task instances.  The .NET Framework provides two (internal) implementations of the TaskScheduler class. Since a Task, based on our decomposition, should be a self-contained piece of code, parallel execution makes sense when executing tasks.  The default implementation of the TaskScheduler class, and the one most often used, is based on the ThreadPool.  This can be retrieved via the TaskScheduler.Default property, and is, by default, what is used when we just start a Task instance with Task.Start(). Normally, when a Task is started by the default TaskScheduler, the task will be treated as a single work item, and run on a ThreadPool thread.  This pools tasks, and provides Task instances all of the advantages of the ThreadPool, including thread pooling for reduced resource usage, and an upper cap on the number of work items.  In addition, .NET 4 brings us a much improved thread pool, providing work stealing and reduced locking within the thread pool queues.  By using the default TaskScheduler, our Tasks are run asynchronously on the ThreadPool. There is one notable exception to my above statements when using the default TaskScheduler.  If a Task is created with the TaskCreationOptions set to TaskCreationOptions.LongRunning, the default TaskScheduler will generate a new thread for that Task, at least in the current implementation.  This is useful for Tasks which will persist for most of the lifetime of your application, since it prevents your Task from starving the ThreadPool of one of it’s work threads. The Task Parallel Library provides one other implementation of the TaskScheduler class.  In addition to providing a way to schedule tasks on the ThreadPool, the framework allows you to create a TaskScheduler which works within a specified SynchronizationContext.  This scheduler can be retrieved within a thread that provides a valid SynchronizationContext by calling the TaskScheduler.FromCurrentSynchronizationContext() method. This implementation of TaskScheduler is intended for use with user interface development.  Windows Forms and Windows Presentation Foundation both require any access to user interface controls to occur on the same thread that created the control.  For example, if you want to set the text within a Windows Forms TextBox, and you’re working on a background thread, that UI call must be marshaled back onto the UI thread.  The most common way this is handled depends on the framework being used.  In Windows Forms, Control.Invoke or Control.BeginInvoke is most often used.  In WPF, the equivelent calls are Dispatcher.Invoke or Dispatcher.BeginInvoke. As an example, say we’re working on a background thread, and we want to update a TextBlock in our user interface with a status label.  The code would typically look something like: // Within background thread work... string status = GetUpdatedStatus(); Dispatcher.BeginInvoke(DispatcherPriority.Normal, new Action( () => { statusLabel.Text = status; })); // Continue on in background method .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This works fine, but forces your method to take a dependency on WPF or Windows Forms.  There is an alternative option, however.  Both Windows Forms and WPF, when initialized, setup a SynchronizationContext in their thread, which is available on the UI thread via the SynchronizationContext.Current property.  This context is used by classes such as BackgroundWorker to marshal calls back onto the UI thread in a framework-agnostic manner. The Task Parallel Library provides the same functionality via the TaskScheduler.FromCurrentSynchronizationContext() method.  When setting up our Tasks, as long as we’re working on the UI thread, we can construct a TaskScheduler via: TaskScheduler uiScheduler = TaskScheduler.FromCurrentSynchronizationContext(); We then can use this scheduler on any thread to marshal data back onto the UI thread.  For example, our code above can then be rewritten as: string status = GetUpdatedStatus(); (new Task(() => { statusLabel.Text = status; })) .Start(uiScheduler); // Continue on in background method This is nice since it allows us to write code that isn’t tied to Windows Forms or WPF, but is still fully functional with those technologies.  I’ll discuss even more uses for the SynchronizationContext based TaskScheduler when I demonstrate task continuations, but even without continuations, this is a very useful construct. In addition to the two implementations provided by the Task Parallel Library, it is possible to implement your own TaskScheduler.  The ParallelExtensionsExtras project within the Samples for Parallel Programming provides nine sample TaskScheduler implementations.  These include schedulers which restrict the maximum number of concurrent tasks, run tasks on a single threaded apartment thread, use a new thread per task, and more.

  Read the article

• Parallelism in .NET – Part 18, Task Continuations with Multiple Tasks

  - by Reed

  In my introduction to Task continuations I demonstrated how the Task class provides a more expressive alternative to traditional callbacks.  Task continuations provide a much cleaner syntax to traditional callbacks, but there are other reasons to switch to using continuations… Task continuations provide a clean syntax, and a very simple, elegant means of synchronizing asynchronous method results with the user interface.  In addition, continuations provide a very simple, elegant means of working with collections of tasks. Prior to .NET 4, working with multiple related asynchronous method calls was very tricky.  If, for example, we wanted to run two asynchronous operations, followed by a single method call which we wanted to run when the first two methods completed, we’d have to program all of the handling ourselves.  We would likely need to take some approach such as using a shared callback which synchronized against a common variable, or using a WaitHandle shared within the callbacks to allow one to wait for the second.  Although this could be accomplished easily enough, it requires manually placing this handling into every algorithm which requires this form of blocking.  This is error prone, difficult, and can easily lead to subtle bugs. Similar to how the Task class static methods providing a way to block until multiple tasks have completed, TaskFactory contains static methods which allow a continuation to be scheduled upon the completion of multiple tasks: TaskFactory.ContinueWhenAll. This allows you to easily specify a single delegate to run when a collection of tasks has completed.  For example, suppose we have a class which fetches data from the network.  This can be a long running operation, and potentially fail in certain situations, such as a server being down.  As a result, we have three separate servers which we will “query” for our information.  Now, suppose we want to grab data from all three servers, and verify that the results are the same from all three. With traditional asynchronous programming in .NET, this would require using three separate callbacks, and managing the synchronization between the various operations ourselves.  The Task and TaskFactory classes simplify this for us, allowing us to write: var server1 = Task.Factory.StartNew( () => networkClass.GetResults(firstServer) ); var server2 = Task.Factory.StartNew( () => networkClass.GetResults(secondServer) ); var server3 = Task.Factory.StartNew( () => networkClass.GetResults(thirdServer) ); var result = Task.Factory.ContinueWhenAll( new[] {server1, server2, server3 }, (tasks) => { // Propogate exceptions (see below) Task.WaitAll(tasks); return this.CompareTaskResults( tasks[0].Result, tasks[1].Result, tasks[2].Result); }); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This is clean, simple, and elegant.  The one complication is the Task.WaitAll(tasks); statement. Although the continuation will not complete until all three tasks (server1, server2, and server3) have completed, there is a potential snag.  If the networkClass.GetResults method fails, and raises an exception, we want to make sure to handle it cleanly.  By using Task.WaitAll, any exceptions raised within any of our original tasks will get wrapped into a single AggregateException by the WaitAll method, providing us a simplified means of handling the exceptions.  If we wait on the continuation, we can trap this AggregateException, and handle it cleanly.  Without this line, it’s possible that an exception could remain uncaught and unhandled by a task, which later might trigger a nasty UnobservedTaskException.  This would happen any time two of our original tasks failed. Just as we can schedule a continuation to occur when an entire collection of tasks has completed, we can just as easily setup a continuation to run when any single task within a collection completes.  If, for example, we didn’t need to compare the results of all three network locations, but only use one, we could still schedule three tasks.  We could then have our completion logic work on the first task which completed, and ignore the others.  This is done via TaskFactory.ContinueWhenAny: var server1 = Task.Factory.StartNew( () => networkClass.GetResults(firstServer) ); var server2 = Task.Factory.StartNew( () => networkClass.GetResults(secondServer) ); var server3 = Task.Factory.StartNew( () => networkClass.GetResults(thirdServer) ); var result = Task.Factory.ContinueWhenAny( new[] {server1, server2, server3 }, (firstTask) => { return this.ProcessTaskResult(firstTask.Result); }); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here, instead of working with all three tasks, we’re just using the first task which finishes.  This is very useful, as it allows us to easily work with results of multiple operations, and “throw away” the others.  However, you must take care when using ContinueWhenAny to properly handle exceptions.  At some point, you should always wait on each task (or use the Task.Result property) in order to propogate any exceptions raised from within the task.  Failing to do so can lead to an UnobservedTaskException.

  Read the article

• MSBuild (.NET 4.0) access problems

  - by JMP

  I'm using Cruise Control .NET as my build server (Windows 2008 Server). Yesterday I upgraded my ASP.NET MVC project from VS 2008/.NET 3.5 to VS 2010/.NET 4.0. The only change I made to my ccnet.config's MSBuild task was the location of MSBuild.exe. Ever since I made that change, the build has been broken with the error: MSB4019 - The imported project "C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v10.0\WebApplications\Microsoft.WebApplication.targets" was not found. Confirm that the path in the declaration is correct, and that the file exists on disk. This file does, in fact, exist in the location specified (I solved a problem similar to this when setting up the build server for VS2008/.NET 3.5 by copying the files from my dev environment to my build environment). So I RDP'ed into the build machine and opened a command prompt, used MSBUILD to attempt to build my project. MSBUILD returns the error: MSB3021 - Unable to copy file "obj\debug....dll". Access to the path 'bin....dll' is denied. Since I'm running MSBUILD from the command prompt, logged in with an account that has administrative privileges, I'm assuming that MSBUILD is running with the same privileges that I have. Next, I tried to copy the file that MSBUILD was attempting to copy. In this case, I get the UAC dialog that makes me click the [Continue] button to complete the copy. I'd like to avoid installing Visual Studio 2010 on my build machine, can anyone suggest other fixes I might try?

  Read the article

< Previous Page | 24 25 26 27 28 29 30 31 32 33 34 35  | Next Page >