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  • Two way replication

    - by Nidzaaaa
    I have a little problem... I have this case: -2 server instances -2 Databases -1 Table (5 columns) From server 1 I created publication to replicate all columns of table I have in 1. DB From server 2 I created subscription to pull all columns from table which is in server 1 DB But now, I need to publicate one columns of same table from server 2 to server 1 and also it has to be in same DB... I tried with using logic and creating publication for server 2 and subscription on server 1 but there is error appearing "You have selected the Publisher as a Subscriber and entered a subscription database that is the same as the publishing database. Select another subscription database." I hope someone understood my problem and have an answer for me, thanks in advance... p.s. Ask for more info if you need ...

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  • XNA: Camera's Rotation and Translation matrices seem to interfere with each other

    - by Danjen
    I've been following the guide here for how to create a custom 2D camera in XNA. It works great, I've implemented it before, but for some reason, the matrix math is throwing me off. public sealed class Camera2D { public Vector2 Origin { get; set; } public Vector2 Position { get; set; } public float Scale { get; set; } public float Rotation { get; set; } } It might be easier to just show you a picture of my problem: http://i.imgur.com/H1l6LEx.png What I want to do is allow the camera to pivot around any given point. Right now, I have the rotations mapped to my shoulder buttons on a gamepad, and if I press them, it should rotate around the point the camera is currently looking at. Then, I use the left stick to move the camera around. The problem is that after it's been rotated, pressing "up" results in it being used relative to the rotation, creating the image above. I understand that matrices have to be applied in a certain order, and that I have to offset the thing to be rotated around the world origin and move it back, but it just won't work! public Matrix GetTransformationMatrix() { Matrix mRotate = Matrix.Identity * Matrix.CreateTranslation(-Origin.X, -Origin.Y, 0.00f) * // Move origin to world center Matrix.CreateRotationZ(MathHelper.ToRadians(Rotation)) * // Apply rotation Matrix.CreateTranslation(+Origin.X, +Origin.Y, 0.00f); // Undo the move operation Matrix mTranslate = Matrix.Identity * Matrix.CreateTranslation(-Position.X, Position.Y, 0.00f); // Apply the actual translation return mRotate * mTranslate; } So to recap, it seems I can have it rotate around an arbitrary point and lose the ability to have "up" move the camera straight up, or I can rotate it around the world origin and have the camera move properly, but not both.

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  • Insufficient Permissions Problems with MSDeploy and TFS Build 2010

    - by jdanforth
    I ran into these problems on a TFS 2010 RC setup where I wanted to deploy a web site as part of the nightly build: C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v10.0\Web\Microsoft.Web.Publishing.targets (3481): Web deployment task failed.(An error occurred when reading the IIS Configuration File 'MACHINE/REDIRECTION'. The identity performing the operation was 'NT AUTHORITY\NETWORK SERVICE'.)  An error occurred when reading the IIS Configuration File 'MACHINE/REDIRECTION'. The identity performing the operation was 'NT AUTHORITY\NETWORK SERVICE'. Filename: \\?\C:\Windows\system32\inetsrv\config\redirection.config Error: Cannot read configuration file due to insufficient permissions  As you can see I’m running the build service as NETWORK SERVICE which is quite usual. The first thing I did then was to give NETWORK SERVICE read access to the whole directory where redirection.config is sitting; C:\Windows\system32\inetsrv\config. That gave me a new error: C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v10.0\Web\Microsoft.Web.Publishing.targets (3481): Web deployment task failed. (Attempted to perform an unauthorized operation.) The reason for this problem was that NETWORK SERVICE didn’t have write permission to the place where I’ve told MSDeploy to put the web site physically on the disk. Once I’d given the NETWORK SERVICE the right permissions, MSDeploy completed as expected! NOTE! I’ve not had this problem with TFS 2010 RTM, so it might be just a RC issue!

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  • USB 3.0 port with USB 3.0 device in Ubuntu 12.10

    - by fernando garcía
    When I try to connect a USB 3.0 device in Ubuntu 12.10 (ASUS K55VD, kernel 3.5.0-19-generic #30-Ubuntu SMP), the system says [ 74.747832] hub 3-0:1.0: unable to enumerate USB device on port 1 [ 74.931957] usb 4-1: new SuperSpeed USB device number 2 using xhci_hcd [ 74.949390] usb 4-1: New USB device found, idVendor=05e3, idProduct=0731 [ 74.949396] usb 4-1: New USB device strings: Mfr=0, Product=1, SerialNumber=2 [ 74.949400] usb 4-1: Product: USB Storage [ 74.949403] usb 4-1: SerialNumber: 0000000000000033 [ 75.033327] usbcore: registered new interface driver uas [ 75.038548] Initializing USB Mass Storage driver... [ 75.038651] scsi7 : usb-storage 4-1:1.0 [ 75.038700] usbcore: registered new interface driver usb-storage [ 75.038701] USB Mass Storage support registered. but it does not recognize the device, and the disks applications (gparted, nautilus) act as if nothing had been connected. I have checked other questions, but either they have no answers or they told about previous Ubuntu version with 3.0.x kernels. A USB 2.0 device will work in the USB 3.0 ports. A USB 3.0 device will work (at USB 2.0 speeds) in the USB 2.0 ports. The problem, as I wrote, is between USB 3.0 devices and USB 3.0 ports. I have my USB 3.0 ports configured without legacy support via the BIOS (the way they should be, I suppose). But I also have tried to configure them with XHCI Preboot mode disabled. Have any one solved a similar problem? Thanks in advance.

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  • Solution: Testing Web Services with MSTest on Team Build

    - by Martin Hinshelwood
    Guess what. About 20 minutes after I fixed the build, Allan broke it again! Update: 4th March 2010 – After having huge problems getting this working I read Billy Wang’s post which showed me the light. The problem here is that even though the test passes locally it will not during an Automated Build. When you send your tests to the build server it does not understand that you want to spin up the web site and run tests against that! When you run the test in Visual Studio it spins up the web site anyway, but would you expect your test to pass if you told the website not to spin up? Of course not. So, when you send the code to the build server you need to tell it what to spin up. First, the best way to get the parameters you need is to right click on the method you want to test and select “Create Unit Test”. This will detect wither you are running in IIS or ASP.NET Development Server or None, and create the relevant tags. Figure: Right clicking on “SaveDefaultProjectFile” will produce a context menu with “Create Unit tests…” on it. If you use this option it will AutoDetect most of the Attributes that are required. /// <summary> ///A test for SSW.SQLDeploy.SilverlightUI.Web.Services.IProfileService.SaveDefaultProjectFile ///</summary> // TODO: Ensure that the UrlToTest attribute specifies a URL to an ASP.NET page (for example, // http://.../Default.aspx). This is necessary for the unit test to be executed on the web server, // whether you are testing a page, web service, or a WCF service. [TestMethod()] [HostType("ASP.NET")] [AspNetDevelopmentServerHost("D:\\Workspaces\\SSW\\SSW\\SqlDeploy\\DEV\\Main\\SSW.SQLDeploy.SilverlightUI.Web", "/")] [UrlToTest("http://localhost:3100/")] [DeploymentItem("SSW.SQLDeploy.SilverlightUI.Web.dll")] public void SaveDefaultProjectFileTest() { IProfileService target = new ProfileService(); // TODO: Initialize to an appropriate value string strComputerName = string.Empty; // TODO: Initialize to an appropriate value bool expected = false; // TODO: Initialize to an appropriate value bool actual; actual = target.SaveDefaultProjectFile(strComputerName); Assert.AreEqual(expected, actual); Assert.Inconclusive("Verify the correctness of this test method."); } Figure: Auto created code that shows the attributes required to run correctly in IIS or in this case ASP.NET Development Server If you are a purist and don’t like creating unit tests like this then you just need to add the three attributes manually. HostType – This attribute specified what host to use. Its an extensibility point, so you could write your own. Or you could just use “ASP.NET”. UrlToTest – This specifies the start URL. For most tests it does not matter which page you call, as long as it is a valid page otherwise your test may not run on the server, but may pass anyway. AspNetDevelopmentServerHost – This is a nasty one, it is only used if you are using ASP.NET Development Host and is unnecessary if you are using IIS. This sets the host settings and the first value MUST be the physical path to the root of your web application. OK, so all that was rubbish and I could not get anything working using the MSDN documentation. Google provided very little help until I ran into Billy Wang’s post  and I heard that heavenly music that all developers hear when understanding dawns that what they have been doing up until now is just plain stupid. I am sure that the above will work when I am doing Web Unit Tests, but there is a much easier way when doing web services. You need to add the AspNetDevelopmentServer attribute to your code. This will tell MSTest to spin up an ASP.NET Development server to host the service. Specify the path to the web application you want to use. [AspNetDevelopmentServer("WebApp1", "D:\\Workspaces\\SSW\\SSW\\SqlDeploy\\DEV\\Main\\SSW.SQLDeploy.SilverlightUI.Web")] [DeploymentItem("SSW.SQLDeploy.SilverlightUI.Web.dll")] [TestMethod] public void ProfileService_Integration_SaveDefaultProjectFile_Returns_True() { ProfileServiceClient target = new ProfileServiceClient(); bool isTrue = target.SaveDefaultProjectFile("Mav"); Assert.AreEqual(true, isTrue); } Figure: This AspNetDevelopmentServer will make sure that the specified web application is launched. Now we can run the test and have it pass, but if the dynamically assigned ASP.NET Development server port changes what happens to the details in your app.config that was generated when creating a reference to the web service? Well, it would be wrong and the test would fail. This is where Billy’s helper method comes in. Once you have created an instance of your service call, and it has loaded the config, but before you make any calls to it you need to go in and dynamically set the Endpoint address to the same address as your dynamically hosted Web Application. using System; using System.Collections.Generic; using System.Linq; using System.Text; using Microsoft.VisualStudio.TestTools.UnitTesting; using System.Reflection; using System.ServiceModel.Description; using System.ServiceModel; namespace SSW.SQLDeploy.Test { class WcfWebServiceHelper { public static bool TryUrlRedirection(object client, TestContext context, string identifier) { bool result = true; try { PropertyInfo property = client.GetType().GetProperty("Endpoint"); string webServer = context.Properties[string.Format("AspNetDevelopmentServer.{0}", identifier)].ToString(); Uri webServerUri = new Uri(webServer); ServiceEndpoint endpoint = (ServiceEndpoint)property.GetValue(client, null); EndpointAddressBuilder builder = new EndpointAddressBuilder(endpoint.Address); builder.Uri = new Uri(endpoint.Address.Uri.OriginalString.Replace(endpoint.Address.Uri.Authority, webServerUri.Authority)); endpoint.Address = builder.ToEndpointAddress(); } catch (Exception e) { context.WriteLine(e.Message); result = false; } return result; } } } Figure: This fixes a problem with the URL in your web.config not being the same as the dynamically hosted ASP.NET Development server port. We can now add a call to this method after we created the Proxy object and change the Endpoint for the Service to the correct one. This process is wrapped in an assert as if it fails there is no point in continuing. [AspNetDevelopmentServer("WebApp1", D:\\Workspaces\\SSW\\SSW\\SqlDeploy\\DEV\\Main\\SSW.SQLDeploy.SilverlightUI.Web")] [DeploymentItem("SSW.SQLDeploy.SilverlightUI.Web.dll")] [TestMethod] public void ProfileService_Integration_SaveDefaultProjectFile_Returns_True() { ProfileServiceClient target = new ProfileServiceClient(); Assert.IsTrue(WcfWebServiceHelper.TryUrlRedirection(target, TestContext, "WebApp1")); bool isTrue = target.SaveDefaultProjectFile("Mav"); Assert.AreEqual(true, isTrue); } Figure: Editing the Endpoint from the app.config on the fly to match the dynamically hosted ASP.NET Development Server URL and port is now easy. As you can imagine AspNetDevelopmentServer poses some problems of you have multiple developers. What are the chances of everyone using the same location to store the source? What about if you are using a build server, how do you tell MSTest where to look for the files? To the rescue is a property called" “%PathToWebRoot%” which is always right on the build server. It will always point to your build drop folder for your solutions web sites. Which will be “\\tfs.ssw.com.au\BuildDrop\[BuildName]\Debug\_PrecompiledWeb\” or whatever your build drop location is. So lets change the code above to add this. [AspNetDevelopmentServer("WebApp1", "%PathToWebRoot%\\SSW.SQLDeploy.SilverlightUI.Web")] [DeploymentItem("SSW.SQLDeploy.SilverlightUI.Web.dll")] [TestMethod] public void ProfileService_Integration_SaveDefaultProjectFile_Returns_True() { ProfileServiceClient target = new ProfileServiceClient(); Assert.IsTrue(WcfWebServiceHelper.TryUrlRedirection(target, TestContext, "WebApp1")); bool isTrue = target.SaveDefaultProjectFile("Mav"); Assert.AreEqual(true, isTrue); } Figure: Adding %PathToWebRoot% to the AspNetDevelopmentServer path makes it work everywhere. Now we have another problem… this will ONLY run on the build server and will fail locally as %PathToWebRoot%’s default value is “C:\Users\[profile]\Documents\Visual Studio 2010\Projects”. Well this sucks… How do we get the test to run on any build server and any developer laptop. Open “Tools | Options | Test Tools | Test Execution” in Visual Studio and you will see a field called “Web application root directory”. This is where you override that default above. Figure: You can override the default website location for tests. In my case I would put in “D:\Workspaces\SSW\SSW\SqlDeploy\DEV\Main” and all the developers working with this branch would put in the folder that they have mapped. Can you see a problem? What is I create a “$/SSW/SqlDeploy/DEV/34567” branch from Main and I want to run tests in there. Well… I would have to change the value above. This is not ideal, but as you can put your projects anywhere on a computer, it has to be done. Conclusion Although this looks convoluted and complicated there are real problems being solved here that mean that you have a test ANYWHERE solution. Any build server, any Developer workstation. Resources: http://billwg.blogspot.com/2009/06/testing-wcf-web-services.html http://tough-to-find.blogspot.com/2008/04/testing-asmx-web-services-in-visual.html http://msdn.microsoft.com/en-us/library/ms243399(VS.100).aspx http://blogs.msdn.com/dscruggs/archive/2008/09/29/web-tests-unit-tests-the-asp-net-development-server-and-code-coverage.aspx http://www.5z5.com/News/?543f8bc8b36b174f Technorati Tags: VS2010,MSTest,Team Build 2010,Team Build,Visual Studio,Visual Studio 2010,Visual Studio ALM,Team Test,Team Test 2010

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  • Using LINQ Distinct: With an Example on ASP.NET MVC SelectListItem

    - by Joe Mayo
    One of the things that might be surprising in the LINQ Distinct standard query operator is that it doesn’t automatically work properly on custom classes. There are reasons for this, which I’ll explain shortly. The example I’ll use in this post focuses on pulling a unique list of names to load into a drop-down list. I’ll explain the sample application, show you typical first shot at Distinct, explain why it won’t work as you expect, and then demonstrate a solution to make Distinct work with any custom class. The technologies I’m using are  LINQ to Twitter, LINQ to Objects, Telerik Extensions for ASP.NET MVC, ASP.NET MVC 2, and Visual Studio 2010. The function of the example program is to show a list of people that I follow.  In Twitter API vernacular, these people are called “Friends”; though I’ve never met most of them in real life. This is part of the ubiquitous language of social networking, and Twitter in particular, so you’ll see my objects named accordingly. Where Distinct comes into play is because I want to have a drop-down list with the names of the friends appearing in the list. Some friends are quite verbose, which means I can’t just extract names from each tweet and populate the drop-down; otherwise, I would end up with many duplicate names. Therefore, Distinct is the appropriate operator to eliminate the extra entries from my friends who tend to be enthusiastic tweeters. The sample doesn’t do anything with the drop-down list and I leave that up to imagination for what it’s practical purpose could be; perhaps a filter for the list if I only want to see a certain person’s tweets or maybe a quick list that I plan to combine with a TextBox and Button to reply to a friend. When the program runs, you’ll need to authenticate with Twitter, because I’m using OAuth (DotNetOpenAuth), for authentication, and then you’ll see the drop-down list of names above the grid with the most recent tweets from friends. Here’s what the application looks like when it runs: As you can see, there is a drop-down list above the grid. The drop-down list is where most of the focus of this article will be. There is some description of the code before we talk about the Distinct operator, but we’ll get there soon. This is an ASP.NET MVC2 application, written with VS 2010. Here’s the View that produces this screen: <%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<TwitterFriendsViewModel>" %> <%@ Import Namespace="DistinctSelectList.Models" %> <asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">     Home Page </asp:Content><asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">     <fieldset>         <legend>Twitter Friends</legend>         <div>             <%= Html.DropDownListFor(                     twendVM => twendVM.FriendNames,                     Model.FriendNames,                     "<All Friends>") %>         </div>         <div>             <% Html.Telerik().Grid<TweetViewModel>(Model.Tweets)                    .Name("TwitterFriendsGrid")                    .Columns(cols =>                     {                         cols.Template(col =>                             { %>                                 <img src="<%= col.ImageUrl %>"                                      alt="<%= col.ScreenName %>" />                         <% });                         cols.Bound(col => col.ScreenName);                         cols.Bound(col => col.Tweet);                     })                    .Render(); %>         </div>     </fieldset> </asp:Content> As shown above, the Grid is from Telerik’s Extensions for ASP.NET MVC. The first column is a template that renders the user’s Avatar from a URL provided by the Twitter query. Both the Grid and DropDownListFor display properties that are collections from a TwitterFriendsViewModel class, shown below: using System.Collections.Generic; using System.Web.Mvc; namespace DistinctSelectList.Models { /// /// For finding friend info on screen /// public class TwitterFriendsViewModel { /// /// Display names of friends in drop-down list /// public List FriendNames { get; set; } /// /// Display tweets in grid /// public List Tweets { get; set; } } } I created the TwitterFreindsViewModel. The two Lists are what the View consumes to populate the DropDownListFor and Grid. Notice that FriendNames is a List of SelectListItem, which is an MVC class. Another custom class I created is the TweetViewModel (the type of the Tweets List), shown below: namespace DistinctSelectList.Models { /// /// Info on friend tweets /// public class TweetViewModel { /// /// User's avatar /// public string ImageUrl { get; set; } /// /// User's Twitter name /// public string ScreenName { get; set; } /// /// Text containing user's tweet /// public string Tweet { get; set; } } } The initial Twitter query returns much more information than we need for our purposes and this a special class for displaying info in the View.  Now you know about the View and how it’s constructed. Let’s look at the controller next. The controller for this demo performs authentication, data retrieval, data manipulation, and view selection. I’ll skip the description of the authentication because it’s a normal part of using OAuth with LINQ to Twitter. Instead, we’ll drill down and focus on the Distinct operator. However, I’ll show you the entire controller, below,  so that you can see how it all fits together: using System.Linq; using System.Web.Mvc; using DistinctSelectList.Models; using LinqToTwitter; namespace DistinctSelectList.Controllers { [HandleError] public class HomeController : Controller { private MvcOAuthAuthorization auth; private TwitterContext twitterCtx; /// /// Display a list of friends current tweets /// /// public ActionResult Index() { auth = new MvcOAuthAuthorization(InMemoryTokenManager.Instance, InMemoryTokenManager.AccessToken); string accessToken = auth.CompleteAuthorize(); if (accessToken != null) { InMemoryTokenManager.AccessToken = accessToken; } if (auth.CachedCredentialsAvailable) { auth.SignOn(); } else { return auth.BeginAuthorize(); } twitterCtx = new TwitterContext(auth); var friendTweets = (from tweet in twitterCtx.Status where tweet.Type == StatusType.Friends select new TweetViewModel { ImageUrl = tweet.User.ProfileImageUrl, ScreenName = tweet.User.Identifier.ScreenName, Tweet = tweet.Text }) .ToList(); var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct() .ToList(); var twendsVM = new TwitterFriendsViewModel { Tweets = friendTweets, FriendNames = friendNames }; return View(twendsVM); } public ActionResult About() { return View(); } } } The important part of the listing above are the LINQ to Twitter queries for friendTweets and friendNames. Both of these results are used in the subsequent population of the twendsVM instance that is passed to the view. Let’s dissect these two statements for clarification and focus on what is happening with Distinct. The query for friendTweets gets a list of the 20 most recent tweets (as specified by the Twitter API for friend queries) and performs a projection into the custom TweetViewModel class, repeated below for your convenience: var friendTweets = (from tweet in twitterCtx.Status where tweet.Type == StatusType.Friends select new TweetViewModel { ImageUrl = tweet.User.ProfileImageUrl, ScreenName = tweet.User.Identifier.ScreenName, Tweet = tweet.Text }) .ToList(); The LINQ to Twitter query above simplifies what we need to work with in the View and the reduces the amount of information we have to look at in subsequent queries. Given the friendTweets above, the next query performs another projection into an MVC SelectListItem, which is required for binding to the DropDownList.  This brings us to the focus of this blog post, writing a correct query that uses the Distinct operator. The query below uses LINQ to Objects, querying the friendTweets collection to get friendNames: var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct() .ToList(); The above implementation of Distinct seems normal, but it is deceptively incorrect. After running the query above, by executing the application, you’ll notice that the drop-down list contains many duplicates.  This will send you back to the code scratching your head, but there’s a reason why this happens. To understand the problem, we must examine how Distinct works in LINQ to Objects. Distinct has two overloads: one without parameters, as shown above, and another that takes a parameter of type IEqualityComparer<T>.  In the case above, no parameters, Distinct will call EqualityComparer<T>.Default behind the scenes to make comparisons as it iterates through the list. You don’t have problems with the built-in types, such as string, int, DateTime, etc, because they all implement IEquatable<T>. However, many .NET Framework classes, such as SelectListItem, don’t implement IEquatable<T>. So, what happens is that EqualityComparer<T>.Default results in a call to Object.Equals, which performs reference equality on reference type objects.  You don’t have this problem with value types because the default implementation of Object.Equals is bitwise equality. However, most of your projections that use Distinct are on classes, just like the SelectListItem used in this demo application. So, the reason why Distinct didn’t produce the results we wanted was because we used a type that doesn’t define its own equality and Distinct used the default reference equality. This resulted in all objects being included in the results because they are all separate instances in memory with unique references. As you might have guessed, the solution to the problem is to use the second overload of Distinct that accepts an IEqualityComparer<T> instance. If you were projecting into your own custom type, you could make that type implement IEqualityComparer<T>, but SelectListItem belongs to the .NET Framework Class Library.  Therefore, the solution is to create a custom type to implement IEqualityComparer<T>, as in the SelectListItemComparer class, shown below: using System.Collections.Generic; using System.Web.Mvc; namespace DistinctSelectList.Models { public class SelectListItemComparer : EqualityComparer { public override bool Equals(SelectListItem x, SelectListItem y) { return x.Value.Equals(y.Value); } public override int GetHashCode(SelectListItem obj) { return obj.Value.GetHashCode(); } } } The SelectListItemComparer class above doesn’t implement IEqualityComparer<SelectListItem>, but rather derives from EqualityComparer<SelectListItem>. Microsoft recommends this approach for consistency with the behavior of generic collection classes. However, if your custom type already derives from a base class, go ahead and implement IEqualityComparer<T>, which will still work. EqualityComparer is an abstract class, that implements IEqualityComparer<T> with Equals and GetHashCode abstract methods. For the purposes of this application, the SelectListItem.Value property is sufficient to determine if two items are equal.   Since SelectListItem.Value is type string, the code delegates equality to the string class. The code also delegates the GetHashCode operation to the string class.You might have other criteria in your own object and would need to define what it means for your object to be equal. Now that we have an IEqualityComparer<SelectListItem>, let’s fix the problem. The code below modifies the query where we want distinct values: var friendNames = (from tweet in friendTweets select new SelectListItem { Text = tweet.ScreenName, Value = tweet.ScreenName }) .Distinct(new SelectListItemComparer()) .ToList(); Notice how the code above passes a new instance of SelectListItemComparer as the parameter to the Distinct operator. Now, when you run the application, the drop-down list will behave as you expect, showing only a unique set of names. In addition to Distinct, other LINQ Standard Query Operators have overloads that accept IEqualityComparer<T>’s, You can use the same techniques as shown here, with SelectListItemComparer, with those other operators as well. Now you know how to resolve problems with getting Distinct to work properly and also have a way to fix problems with other operators that require equality comparisons. @JoeMayo

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  • SSH main process ended

    - by Khaled
    I have a running ubuntu server 10.04.1. When I tried to login to the server via ssh, I could not. Instead, I got connection refused error. I tried to ping the machine and I got reply! So, the clear reason is that SSH daemon is stopped. After reboot, I was able to login to my server via ssh. After some time, I looked at my logs /var/log/syslog and found the following records: Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2465) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2469) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2473) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2477) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2481) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2485) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2489) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2493) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2497) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2501) terminated with status 255 Jan 16 10:57:09 myserver init: ssh respawning too fast, stopped I searched for a similar problem/solution. Some people said that this is caused by the SSH daemon trying to start before networking and they suggest to change ListenAddress in /etc/ssh/sshd_config to be 0.0.0.0. I think this is not the cause in my case, because my problem occurs after system is up and running. Any idea what is causing this? This is ubuntu server and it should be running and accessed remotely using ssh.

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  • Agile Development

    - by James Oloo Onyango
    Alot of literature has and is being written about agile developement and its surrounding philosophies. In my quest to find the best way to express the importance of agile methodologies, i have found Robert C. Martin's "A Satire Of Two Companies" to be both the most concise and thorough! Enjoy the read! Rufus Inc Project Kick Off Your name is Bob. The date is January 3, 2001, and your head still aches from the recent millennial revelry. You are sitting in a conference room with several managers and a group of your peers. You are a project team leader. Your boss is there, and he has brought along all of his team leaders. His boss called the meeting. "We have a new project to develop," says your boss's boss. Call him BB. The points in his hair are so long that they scrape the ceiling. Your boss's points are just starting to grow, but he eagerly awaits the day when he can leave Brylcream stains on the acoustic tiles. BB describes the essence of the new market they have identified and the product they want to develop to exploit this market. "We must have this new project up and working by fourth quarter October 1," BB demands. "Nothing is of higher priority, so we are cancelling your current project." The reaction in the room is stunned silence. Months of work are simply going to be thrown away. Slowly, a murmur of objection begins to circulate around the conference table.   His points give off an evil green glow as BB meets the eyes of everyone in the room. One by one, that insidious stare reduces each attendee to quivering lumps of protoplasm. It is clear that he will brook no discussion on this matter. Once silence has been restored, BB says, "We need to begin immediately. How long will it take you to do the analysis?" You raise your hand. Your boss tries to stop you, but his spitwad misses you and you are unaware of his efforts.   "Sir, we can't tell you how long the analysis will take until we have some requirements." "The requirements document won't be ready for 3 or 4 weeks," BB says, his points vibrating with frustration. "So, pretend that you have the requirements in front of you now. How long will you require for analysis?" No one breathes. Everyone looks around to see whether anyone has some idea. "If analysis goes beyond April 1, we have a problem. Can you finish the analysis by then?" Your boss visibly gathers his courage: "We'll find a way, sir!" His points grow 3 mm, and your headache increases by two Tylenol. "Good." BB smiles. "Now, how long will it take to do the design?" "Sir," you say. Your boss visibly pales. He is clearly worried that his 3 mms are at risk. "Without an analysis, it will not be possible to tell you how long design will take." BB's expression shifts beyond austere.   "PRETEND you have the analysis already!" he says, while fixing you with his vacant, beady little eyes. "How long will it take you to do the design?" Two Tylenol are not going to cut it. Your boss, in a desperate attempt to save his new growth, babbles: "Well, sir, with only six months left to complete the project, design had better take no longer than 3 months."   "I'm glad you agree, Smithers!" BB says, beaming. Your boss relaxes. He knows his points are secure. After a while, he starts lightly humming the Brylcream jingle. BB continues, "So, analysis will be complete by April 1, design will be complete by July 1, and that gives you 3 months to implement the project. This meeting is an example of how well our new consensus and empowerment policies are working. Now, get out there and start working. I'll expect to see TQM plans and QIT assignments on my desk by next week. Oh, and don't forget that your crossfunctional team meetings and reports will be needed for next month's quality audit." "Forget the Tylenol," you think to yourself as you return to your cubicle. "I need bourbon."   Visibly excited, your boss comes over to you and says, "Gosh, what a great meeting. I think we're really going to do some world shaking with this project." You nod in agreement, too disgusted to do anything else. "Oh," your boss continues, "I almost forgot." He hands you a 30-page document. "Remember that the SEI is coming to do an evaluation next week. This is the evaluation guide. You need to read through it, memorize it, and then shred it. It tells you how to answer any questions that the SEI auditors ask you. It also tells you what parts of the building you are allowed to take them to and what parts to avoid. We are determined to be a CMM level 3 organization by June!"   You and your peers start working on the analysis of the new project. This is difficult because you have no requirements. But from the 10-minute introduction given by BB on that fateful morning, you have some idea of what the product is supposed to do.   Corporate process demands that you begin by creating a use case document. You and your team begin enumerating use cases and drawing oval and stick diagrams. Philosophical debates break out among the team members. There is disagreement as to whether certain use cases should be connected with <<extends>> or <<includes>> relationships. Competing models are created, but nobody knows how to evaluate them. The debate continues, effectively paralyzing progress.   After a week, somebody finds the iceberg.com Web site, which recommends disposing entirely of <<extends>> and <<includes>> and replacing them with <<precedes>> and <<uses>>. The documents on this Web site, authored by Don Sengroiux, describes a method known as stalwart-analysis, which claims to be a step-by-step method for translating use cases into design diagrams. More competing use case models are created using this new scheme, but again, people can't agree on how to evaluate them. The thrashing continues. More and more, the use case meetings are driven by emotion rather than by reason. If it weren't for the fact that you don't have requirements, you'd be pretty upset by the lack of progress you are making. The requirements document arrives on February 15. And then again on February 20, 25, and every week thereafter. Each new version contradicts the previous one. Clearly, the marketing folks who are writing the requirements, empowered though they might be, are not finding consensus.   At the same time, several new competing use case templates have been proposed by the various team members. Each template presents its own particularly creative way of delaying progress. The debates rage on. On March 1, Prudence Putrigence, the process proctor, succeeds in integrating all the competing use case forms and templates into a single, all-encompassing form. Just the blank form is 15 pages long. She has managed to include every field that appeared on all the competing templates. She also presents a 159- page document describing how to fill out the use case form. All current use cases must be rewritten according to the new standard.   You marvel to yourself that it now requires 15 pages of fill-in-the-blank and essay questions to answer the question: What should the system do when the user presses Return? The corporate process (authored by L. E. Ott, famed author of "Holistic Analysis: A Progressive Dialectic for Software Engineers") insists that you discover all primary use cases, 87 percent of all secondary use cases, and 36.274 percent of all tertiary use cases before you can complete analysis and enter the design phase. You have no idea what a tertiary use case is. So in an attempt to meet this requirement, you try to get your use case document reviewed by the marketing department, which you hope will know what a tertiary use case is.   Unfortunately, the marketing folks are too busy with sales support to talk to you. Indeed, since the project started, you have not been able to get a single meeting with marketing, which has provided a never-ending stream of changing and contradictory requirements documents.   While one team has been spinning endlessly on the use case document, another team has been working out the domain model. Endless variations of UML documents are pouring out of this team. Every week, the model is reworked.   The team members can't decide whether to use <<interfaces>> or <<types>> in the model. A huge disagreement has been raging on the proper syntax and application of OCL. Others on the team just got back from a 5-day class on catabolism, and have been producing incredibly detailed and arcane diagrams that nobody else can fathom.   On March 27, with one week to go before analysis is to be complete, you have produced a sea of documents and diagrams but are no closer to a cogent analysis of the problem than you were on January 3. **** And then, a miracle happens.   **** On Saturday, April 1, you check your e-mail from home. You see a memo from your boss to BB. It states unequivocally that you are done with the analysis! You phone your boss and complain. "How could you have told BB that we were done with the analysis?" "Have you looked at a calendar lately?" he responds. "It's April 1!" The irony of that date does not escape you. "But we have so much more to think about. So much more to analyze! We haven't even decided whether to use <<extends>> or <<precedes>>!" "Where is your evidence that you are not done?" inquires your boss, impatiently. "Whaaa . . . ." But he cuts you off. "Analysis can go on forever; it has to be stopped at some point. And since this is the date it was scheduled to stop, it has been stopped. Now, on Monday, I want you to gather up all existing analysis materials and put them into a public folder. Release that folder to Prudence so that she can log it in the CM system by Monday afternoon. Then get busy and start designing."   As you hang up the phone, you begin to consider the benefits of keeping a bottle of bourbon in your bottom desk drawer. They threw a party to celebrate the on-time completion of the analysis phase. BB gave a colon-stirring speech on empowerment. And your boss, another 3 mm taller, congratulated his team on the incredible show of unity and teamwork. Finally, the CIO takes the stage to tell everyone that the SEI audit went very well and to thank everyone for studying and shredding the evaluation guides that were passed out. Level 3 now seems assured and will be awarded by June. (Scuttlebutt has it that managers at the level of BB and above are to receive significant bonuses once the SEI awards level 3.)   As the weeks flow by, you and your team work on the design of the system. Of course, you find that the analysis that the design is supposedly based on is flawedno, useless; no, worse than useless. But when you tell your boss that you need to go back and work some more on the analysis to shore up its weaker sections, he simply states, "The analysis phase is over. The only allowable activity is design. Now get back to it."   So, you and your team hack the design as best you can, unsure of whether the requirements have been properly analyzed. Of course, it really doesn't matter much, since the requirements document is still thrashing with weekly revisions, and the marketing department still refuses to meet with you.     The design is a nightmare. Your boss recently misread a book named The Finish Line in which the author, Mark DeThomaso, blithely suggested that design documents should be taken down to code-level detail. "If we are going to be working at that level of detail," you ask, "why don't we simply write the code instead?" "Because then you wouldn't be designing, of course. And the only allowable activity in the design phase is design!" "Besides," he continues, "we have just purchased a companywide license for Dandelion! This tool enables 'Round the Horn Engineering!' You are to transfer all design diagrams into this tool. It will automatically generate our code for us! It will also keep the design diagrams in sync with the code!" Your boss hands you a brightly colored shrinkwrapped box containing the Dandelion distribution. You accept it numbly and shuffle off to your cubicle. Twelve hours, eight crashes, one disk reformatting, and eight shots of 151 later, you finally have the tool installed on your server. You consider the week your team will lose while attending Dandelion training. Then you smile and think, "Any week I'm not here is a good week." Design diagram after design diagram is created by your team. Dandelion makes it very difficult to draw these diagrams. There are dozens and dozens of deeply nested dialog boxes with funny text fields and check boxes that must all be filled in correctly. And then there's the problem of moving classes between packages. At first, these diagram are driven from the use cases. But the requirements are changing so often that the use cases rapidly become meaningless. Debates rage about whether VISITOR or DECORATOR design patterns should be used. One developer refuses to use VISITOR in any form, claiming that it's not a properly object-oriented construct. Someone refuses to use multiple inheritance, since it is the spawn of the devil. Review meetings rapidly degenerate into debates about the meaning of object orientation, the definition of analysis versus design, or when to use aggregation versus association. Midway through the design cycle, the marketing folks announce that they have rethought the focus of the system. Their new requirements document is completely restructured. They have eliminated several major feature areas and replaced them with feature areas that they anticipate customer surveys will show to be more appropriate. You tell your boss that these changes mean that you need to reanalyze and redesign much of the system. But he says, "The analysis phase is system. But he says, "The analysis phase is over. The only allowable activity is design. Now get back to it."   You suggest that it might be better to create a simple prototype to show to the marketing folks and even some potential customers. But your boss says, "The analysis phase is over. The only allowable activity is design. Now get back to it." Hack, hack, hack, hack. You try to create some kind of a design document that might reflect the new requirements documents. However, the revolution of the requirements has not caused them to stop thrashing. Indeed, if anything, the wild oscillations of the requirements document have only increased in frequency and amplitude.   You slog your way through them.   On June 15, the Dandelion database gets corrupted. Apparently, the corruption has been progressive. Small errors in the DB accumulated over the months into bigger and bigger errors. Eventually, the CASE tool just stopped working. Of course, the slowly encroaching corruption is present on all the backups. Calls to the Dandelion technical support line go unanswered for several days. Finally, you receive a brief e-mail from Dandelion, informing you that this is a known problem and that the solution is to purchase the new version, which they promise will be ready some time next quarter, and then reenter all the diagrams by hand.   ****   Then, on July 1 another miracle happens! You are done with the design!   Rather than go to your boss and complain, you stock your middle desk drawer with some vodka.   **** They threw a party to celebrate the on-time completion of the design phase and their graduation to CMM level 3. This time, you find BB's speech so stirring that you have to use the restroom before it begins. New banners and plaques are all over your workplace. They show pictures of eagles and mountain climbers, and they talk about teamwork and empowerment. They read better after a few scotches. That reminds you that you need to clear out your file cabinet to make room for the brandy. You and your team begin to code. But you rapidly discover that the design is lacking in some significant areas. Actually, it's lacking any significance at all. You convene a design session in one of the conference rooms to try to work through some of the nastier problems. But your boss catches you at it and disbands the meeting, saying, "The design phase is over. The only allowable activity is coding. Now get back to it."   ****   The code generated by Dandelion is really hideous. It turns out that you and your team were using association and aggregation the wrong way, after all. All the generated code has to be edited to correct these flaws. Editing this code is extremely difficult because it has been instrumented with ugly comment blocks that have special syntax that Dandelion needs in order to keep the diagrams in sync with the code. If you accidentally alter one of these comments, the diagrams will be regenerated incorrectly. It turns out that "Round the Horn Engineering" requires an awful lot of effort. The more you try to keep the code compatible with Dandelion, the more errors Dandelion generates. In the end, you give up and decide to keep the diagrams up to date manually. A second later, you decide that there's no point in keeping the diagrams up to date at all. Besides, who has time?   Your boss hires a consultant to build tools to count the number of lines of code that are being produced. He puts a big thermometer graph on the wall with the number 1,000,000 on the top. Every day, he extends the red line to show how many lines have been added. Three days after the thermometer appears on the wall, your boss stops you in the hall. "That graph isn't growing quickly enough. We need to have a million lines done by October 1." "We aren't even sh-sh-sure that the proshect will require a m-million linezh," you blather. "We have to have a million lines done by October 1," your boss reiterates. His points have grown again, and the Grecian formula he uses on them creates an aura of authority and competence. "Are you sure your comment blocks are big enough?" Then, in a flash of managerial insight, he says, "I have it! I want you to institute a new policy among the engineers. No line of code is to be longer than 20 characters. Any such line must be split into two or more preferably more. All existing code needs to be reworked to this standard. That'll get our line count up!"   You decide not to tell him that this will require two unscheduled work months. You decide not to tell him anything at all. You decide that intravenous injections of pure ethanol are the only solution. You make the appropriate arrangements. Hack, hack, hack, and hack. You and your team madly code away. By August 1, your boss, frowning at the thermometer on the wall, institutes a mandatory 50-hour workweek.   Hack, hack, hack, and hack. By September 1st, the thermometer is at 1.2 million lines and your boss asks you to write a report describing why you exceeded the coding budget by 20 percent. He institutes mandatory Saturdays and demands that the project be brought back down to a million lines. You start a campaign of remerging lines. Hack, hack, hack, and hack. Tempers are flaring; people are quitting; QA is raining trouble reports down on you. Customers are demanding installation and user manuals; salespeople are demanding advance demonstrations for special customers; the requirements document is still thrashing, the marketing folks are complaining that the product isn't anything like they specified, and the liquor store won't accept your credit card anymore. Something has to give.    On September 15, BB calls a meeting. As he enters the room, his points are emitting clouds of steam. When he speaks, the bass overtones of his carefully manicured voice cause the pit of your stomach to roll over. "The QA manager has told me that this project has less than 50 percent of the required features implemented. He has also informed me that the system crashes all the time, yields wrong results, and is hideously slow. He has also complained that he cannot keep up with the continuous train of daily releases, each more buggy than the last!" He stops for a few seconds, visibly trying to compose himself. "The QA manager estimates that, at this rate of development, we won't be able to ship the product until December!" Actually, you think it's more like March, but you don't say anything. "December!" BB roars with such derision that people duck their heads as though he were pointing an assault rifle at them. "December is absolutely out of the question. Team leaders, I want new estimates on my desk in the morning. I am hereby mandating 65-hour work weeks until this project is complete. And it better be complete by November 1."   As he leaves the conference room, he is heard to mutter: "Empowermentbah!" * * * Your boss is bald; his points are mounted on BB's wall. The fluorescent lights reflecting off his pate momentarily dazzle you. "Do you have anything to drink?" he asks. Having just finished your last bottle of Boone's Farm, you pull a bottle of Thunderbird from your bookshelf and pour it into his coffee mug. "What's it going to take to get this project done? " he asks. "We need to freeze the requirements, analyze them, design them, and then implement them," you say callously. "By November 1?" your boss exclaims incredulously. "No way! Just get back to coding the damned thing." He storms out, scratching his vacant head.   A few days later, you find that your boss has been transferred to the corporate research division. Turnover has skyrocketed. Customers, informed at the last minute that their orders cannot be fulfilled on time, have begun to cancel their orders. Marketing is re-evaluating whether this product aligns with the overall goals of the company. Memos fly, heads roll, policies change, and things are, overall, pretty grim. Finally, by March, after far too many sixty-five hour weeks, a very shaky version of the software is ready. In the field, bug-discovery rates are high, and the technical support staff are at their wits' end, trying to cope with the complaints and demands of the irate customers. Nobody is happy.   In April, BB decides to buy his way out of the problem by licensing a product produced by Rupert Industries and redistributing it. The customers are mollified, the marketing folks are smug, and you are laid off.     Rupert Industries: Project Alpha   Your name is Robert. The date is January 3, 2001. The quiet hours spent with your family this holiday have left you refreshed and ready for work. You are sitting in a conference room with your team of professionals. The manager of the division called the meeting. "We have some ideas for a new project," says the division manager. Call him Russ. He is a high-strung British chap with more energy than a fusion reactor. He is ambitious and driven but understands the value of a team. Russ describes the essence of the new market opportunity the company has identified and introduces you to Jane, the marketing manager, who is responsible for defining the products that will address it. Addressing you, Jane says, "We'd like to start defining our first product offering as soon as possible. When can you and your team meet with me?" You reply, "We'll be done with the current iteration of our project this Friday. We can spare a few hours for you between now and then. After that, we'll take a few people from the team and dedicate them to you. We'll begin hiring their replacements and the new people for your team immediately." "Great," says Russ, "but I want you to understand that it is critical that we have something to exhibit at the trade show coming up this July. If we can't be there with something significant, we'll lose the opportunity."   "I understand," you reply. "I don't yet know what it is that you have in mind, but I'm sure we can have something by July. I just can't tell you what that something will be right now. In any case, you and Jane are going to have complete control over what we developers do, so you can rest assured that by July, you'll have the most important things that can be accomplished in that time ready to exhibit."   Russ nods in satisfaction. He knows how this works. Your team has always kept him advised and allowed him to steer their development. He has the utmost confidence that your team will work on the most important things first and will produce a high-quality product.   * * *   "So, Robert," says Jane at their first meeting, "How does your team feel about being split up?" "We'll miss working with each other," you answer, "but some of us were getting pretty tired of that last project and are looking forward to a change. So, what are you people cooking up?" Jane beams. "You know how much trouble our customers currently have . . ." And she spends a half hour or so describing the problem and possible solution. "OK, wait a second" you respond. "I need to be clear about this." And so you and Jane talk about how this system might work. Some of her ideas aren't fully formed. You suggest possible solutions. She likes some of them. You continue discussing.   During the discussion, as each new topic is addressed, Jane writes user story cards. Each card represents something that the new system has to do. The cards accumulate on the table and are spread out in front of you. Both you and Jane point at them, pick them up, and make notes on them as you discuss the stories. The cards are powerful mnemonic devices that you can use to represent complex ideas that are barely formed.   At the end of the meeting, you say, "OK, I've got a general idea of what you want. I'm going to talk to the team about it. I imagine they'll want to run some experiments with various database structures and presentation formats. Next time we meet, it'll be as a group, and we'll start identifying the most important features of the system."   A week later, your nascent team meets with Jane. They spread the existing user story cards out on the table and begin to get into some of the details of the system. The meeting is very dynamic. Jane presents the stories in the order of their importance. There is much discussion about each one. The developers are concerned about keeping the stories small enough to estimate and test. So they continually ask Jane to split one story into several smaller stories. Jane is concerned that each story have a clear business value and priority, so as she splits them, she makes sure that this stays true.   The stories accumulate on the table. Jane writes them, but the developers make notes on them as needed. Nobody tries to capture everything that is said; the cards are not meant to capture everything but are simply reminders of the conversation.   As the developers become more comfortable with the stories, they begin writing estimates on them. These estimates are crude and budgetary, but they give Jane an idea of what the story will cost.   At the end of the meeting, it is clear that many more stories could be discussed. It is also clear that the most important stories have been addressed and that they represent several months worth of work. Jane closes the meeting by taking the cards with her and promising to have a proposal for the first release in the morning.   * * *   The next morning, you reconvene the meeting. Jane chooses five cards and places them on the table. "According to your estimates, these cards represent about one perfect team-week's worth of work. The last iteration of the previous project managed to get one perfect team-week done in 3 real weeks. If we can get these five stories done in 3 weeks, we'll be able to demonstrate them to Russ. That will make him feel very comfortable about our progress." Jane is pushing it. The sheepish look on her face lets you know that she knows it too. You reply, "Jane, this is a new team, working on a new project. It's a bit presumptuous to expect that our velocity will be the same as the previous team's. However, I met with the team yesterday afternoon, and we all agreed that our initial velocity should, in fact, be set to one perfectweek for every 3 real-weeks. So you've lucked out on this one." "Just remember," you continue, "that the story estimates and the story velocity are very tentative at this point. We'll learn more when we plan the iteration and even more when we implement it."   Jane looks over her glasses at you as if to say "Who's the boss around here, anyway?" and then smiles and says, "Yeah, don't worry. I know the drill by now."Jane then puts 15 more cards on the table. She says, "If we can get all these cards done by the end of March, we can turn the system over to our beta test customers. And we'll get good feedback from them."   You reply, "OK, so we've got our first iteration defined, and we have the stories for the next three iterations after that. These four iterations will make our first release."   "So," says Jane, can you really do these five stories in the next 3 weeks?" "I don't know for sure, Jane," you reply. "Let's break them down into tasks and see what we get."   So Jane, you, and your team spend the next several hours taking each of the five stories that Jane chose for the first iteration and breaking them down into small tasks. The developers quickly realize that some of the tasks can be shared between stories and that other tasks have commonalities that can probably be taken advantage of. It is clear that potential designs are popping into the developers' heads. From time to time, they form little discussion knots and scribble UML diagrams on some cards.   Soon, the whiteboard is filled with the tasks that, once completed, will implement the five stories for this iteration. You start the sign-up process by saying, "OK, let's sign up for these tasks." "I'll take the initial database generation." Says Pete. "That's what I did on the last project, and this doesn't look very different. I estimate it at two of my perfect workdays." "OK, well, then, I'll take the login screen," says Joe. "Aw, darn," says Elaine, the junior member of the team, "I've never done a GUI, and kinda wanted to try that one."   "Ah, the impatience of youth," Joe says sagely, with a wink in your direction. "You can assist me with it, young Jedi." To Jane: "I think it'll take me about three of my perfect workdays."   One by one, the developers sign up for tasks and estimate them in terms of their own perfect workdays. Both you and Jane know that it is best to let the developers volunteer for tasks than to assign the tasks to them. You also know full well that you daren't challenge any of the developers' estimates. You know these people, and you trust them. You know that they are going to do the very best they can.   The developers know that they can't sign up for more perfect workdays than they finished in the last iteration they worked on. Once each developer has filled his or her schedule for the iteration, they stop signing up for tasks.   Eventually, all the developers have stopped signing up for tasks. But, of course, tasks are still left on the board.   "I was worried that that might happen," you say, "OK, there's only one thing to do, Jane. We've got too much to do in this iteration. What stories or tasks can we remove?" Jane sighs. She knows that this is the only option. Working overtime at the beginning of a project is insane, and projects where she's tried it have not fared well.   So Jane starts to remove the least-important functionality. "Well, we really don't need the login screen just yet. We can simply start the system in the logged-in state." "Rats!" cries Elaine. "I really wanted to do that." "Patience, grasshopper." says Joe. "Those who wait for the bees to leave the hive will not have lips too swollen to relish the honey." Elaine looks confused. Everyone looks confused. "So . . .," Jane continues, "I think we can also do away with . . ." And so, bit by bit, the list of tasks shrinks. Developers who lose a task sign up for one of the remaining ones.   The negotiation is not painless. Several times, Jane exhibits obvious frustration and impatience. Once, when tensions are especially high, Elaine volunteers, "I'll work extra hard to make up some of the missing time." You are about to correct her when, fortunately, Joe looks her in the eye and says, "When once you proceed down the dark path, forever will it dominate your destiny."   In the end, an iteration acceptable to Jane is reached. It's not what Jane wanted. Indeed, it is significantly less. But it's something the team feels that can be achieved in the next 3 weeks.   And, after all, it still addresses the most important things that Jane wanted in the iteration. "So, Jane," you say when things had quieted down a bit, "when can we expect acceptance tests from you?" Jane sighs. This is the other side of the coin. For every story the development team implements,   Jane must supply a suite of acceptance tests that prove that it works. And the team needs these long before the end of the iteration, since they will certainly point out differences in the way Jane and the developers imagine the system's behaviour.   "I'll get you some example test scripts today," Jane promises. "I'll add to them every day after that. You'll have the entire suite by the middle of the iteration."   * * *   The iteration begins on Monday morning with a flurry of Class, Responsibilities, Collaborators sessions. By midmorning, all the developers have assembled into pairs and are rapidly coding away. "And now, my young apprentice," Joe says to Elaine, "you shall learn the mysteries of test-first design!"   "Wow, that sounds pretty rad," Elaine replies. "How do you do it?" Joe beams. It's clear that he has been anticipating this moment. "OK, what does the code do right now?" "Huh?" replied Elaine, "It doesn't do anything at all; there is no code."   "So, consider our task; can you think of something the code should do?" "Sure," Elaine said with youthful assurance, "First, it should connect to the database." "And thereupon, what must needs be required to connecteth the database?" "You sure talk weird," laughed Elaine. "I think we'd have to get the database object from some registry and call the Connect() method. "Ah, astute young wizard. Thou perceives correctly that we requireth an object within which we can cacheth the database object." "Is 'cacheth' really a word?" "It is when I say it! So, what test can we write that we know the database registry should pass?" Elaine sighs. She knows she'll just have to play along. "We should be able to create a database object and pass it to the registry in a Store() method. And then we should be able to pull it out of the registry with a Get() method and make sure it's the same object." "Oh, well said, my prepubescent sprite!" "Hay!" "So, now, let's write a test function that proves your case." "But shouldn't we write the database object and registry object first?" "Ah, you've much to learn, my young impatient one. Just write the test first." "But it won't even compile!" "Are you sure? What if it did?" "Uh . . ." "Just write the test, Elaine. Trust me." And so Joe, Elaine, and all the other developers began to code their tasks, one test case at a time. The room in which they worked was abuzz with the conversations between the pairs. The murmur was punctuated by an occasional high five when a pair managed to finish a task or a difficult test case.   As development proceeded, the developers changed partners once or twice a day. Each developer got to see what all the others were doing, and so knowledge of the code spread generally throughout the team.   Whenever a pair finished something significant whether a whole task or simply an important part of a task they integrated what they had with the rest of the system. Thus, the code base grew daily, and integration difficulties were minimized.   The developers communicated with Jane on a daily basis. They'd go to her whenever they had a question about the functionality of the system or the interpretation of an acceptance test case.   Jane, good as her word, supplied the team with a steady stream of acceptance test scripts. The team read these carefully and thereby gained a much better understanding of what Jane expected the system to do. By the beginning of the second week, there was enough functionality to demonstrate to Jane. She watched eagerly as the demonstration passed test case after test case. "This is really cool," Jane said as the demonstration finally ended. "But this doesn't seem like one-third of the tasks. Is your velocity slower than anticipated?"   You grimace. You'd been waiting for a good time to mention this to Jane but now she was forcing the issue. "Yes, unfortunately, we are going more slowly than we had expected. The new application server we are using is turning out to be a pain to configure. Also, it takes forever to reboot, and we have to reboot it whenever we make even the slightest change to its configuration."   Jane eyes you with suspicion. The stress of last Monday's negotiations had still not entirely dissipated. She says, "And what does this mean to our schedule? We can't slip it again, we just can't. Russ will have a fit! He'll haul us all into the woodshed and ream us some new ones."   You look Jane right in the eyes. There's no pleasant way to give someone news like this. So you just blurt out, "Look, if things keep going like they're going, we're not going to be done with everything by next Friday. Now it's possible that we'll figure out a way to go faster. But, frankly, I wouldn't depend on that. You should start thinking about one or two tasks that could be removed from the iteration without ruining the demonstration for Russ. Come hell or high water, we are going to give that demonstration on Friday, and I don't think you want us to choose which tasks to omit."   "Aw forchrisakes!" Jane barely manages to stifle yelling that last word as she stalks away, shaking her head. Not for the first time, you say to yourself, "Nobody ever promised me project management would be easy." You are pretty sure it won't be the last time, either.   Actually, things went a bit better than you had hoped. The team did, in fact, have to drop one task from the iteration, but Jane had chosen wisely, and the demonstration for Russ went without a hitch. Russ was not impressed with the progress, but neither was he dismayed. He simply said, "This is pretty good. But remember, we have to be able to demonstrate this system at the trade show in July, and at this rate, it doesn't look like you'll have all that much to show." Jane, whose attitude had improved dramatically with the completion of the iteration, responded to Russ by saying, "Russ, this team is working hard, and well. When July comes around, I am confident that we'll have something significant to demonstrate. It won't be everything, and some of it may be smoke and mirrors, but we'll have something."   Painful though the last iteration was, it had calibrated your velocity numbers. The next iteration went much better. Not because your team got more done than in the last iteration but simply because the team didn't have to remove any tasks or stories in the middle of the iteration.   By the start of the fourth iteration, a natural rhythm has been established. Jane, you, and the team know exactly what to expect from one another. The team is running hard, but the pace is sustainable. You are confident that the team can keep up this pace for a year or more.   The number of surprises in the schedule diminishes to near zero; however, the number of surprises in the requirements does not. Jane and Russ frequently look over the growing system and make recommendations or changes to the existing functionality. But all parties realize that these changes take time and must be scheduled. So the changes do not cause anyone's expectations to be violated. In March, there is a major demonstration of the system to the board of directors. The system is very limited and is not yet in a form good enough to take to the trade show, but progress is steady, and the board is reasonably impressed.   The second release goes even more smoothly than the first. By now, the team has figured out a way to automate Jane's acceptance test scripts. The team has also refactored the design of the system to the point that it is really easy to add new features and change old ones. The second release was done by the end of June and was taken to the trade show. It had less in it than Jane and Russ would have liked, but it did demonstrate the most important features of the system. Although customers at the trade show noticed that certain features were missing, they were very impressed overall. You, Russ, and Jane all returned from the trade show with smiles on your faces. You all felt as though this project was a winner.   Indeed, many months later, you are contacted by Rufus Inc. That company had been working on a system like this for its internal operations. Rufus has canceled the development of that system after a death-march project and is negotiating to license your technology for its environment.   Indeed, things are looking up!

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  • How do I blend 2 lightmaps for day/night cycle in Unity?

    - by Timothy Williams
    Before I say anything else: I'm using dual lightmaps, meaning I need to blend both a near and a far. So I've been working on this for a while now, I have a whole day/night cycle set up for renderers and lighting, and everything is working fine and not process intensive. The only problem I'm having is figuring out how I could blend two lightmaps together, I've figured out how to switch lightmaps, but the problem is that looks kind of abrupt and interrupts the experience. I've done hours of research on this, tried all kinds of shaders, pixel by pixel blending, and everything else to no real avail. Pixel by pixel blending in C# turned out to be a bit process intensive for my liking, though I'm still working on cleaning it up and making it run more smoothly. Shaders looked promising, but I couldn't find a shader that could properly blend two lightmaps. Does anyone have any leads on how I could accomplish this? I just need some sort of smooth transition between my daytime and nighttime lightmap. Perhaps I could overlay the two textures and use an alpha channel? Or something like that?

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  • SSH server not working (respawns until stopped)

    - by Khaled
    I have a running Ubuntu Server 10.04.1. When I tried to login to the server via ssh, I could not. Instead, I got connection refused error. I tried to ping the machine and I got reply! So, the clear reason is that SSH daemon is stopped. After reboot, I was able to login to my server via ssh. After some time, I looked at my logs /var/log/syslog and found the following records: Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2465) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2469) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2473) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2477) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2481) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2485) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2489) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2493) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2497) terminated with status 255 Jan 16 10:57:09 myserver init: ssh main process ended, respawning Jan 16 10:57:09 myserver init: ssh main process (2501) terminated with status 255 Jan 16 10:57:09 myserver init: ssh respawning too fast, stopped I searched for a similar problem/solution. Some people said that this is caused by the SSH daemon trying to start before networking and they suggest to change ListenAddress in /etc/ssh/sshd_config to be 0.0.0.0. I think this is not the cause in my case, because my problem occurs after system is up and running. Any idea what is causing this? This is Ubuntu Server and it should be running and accessed remotely using SSH.

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  • SQL SERVER – Information Related to DATETIME and DATETIME2

    - by pinaldave
    I recently received interesting comment on the blog regarding workaround to overcome the precision issue while dealing with DATETIME and DATETIME2. I have written over this subject earlier over here. SQL SERVER – Difference Between GETDATE and SYSDATETIME SQL SERVER – Difference Between DATETIME and DATETIME2 – WITH GETDATE SQL SERVER – Difference Between DATETIME and DATETIME2 SQL Expert Jing Sheng Zhong has left following comment: The issue you found in SQL server new datetime type is related time source function precision. Folks have found the root reason of the problem – when data time values are converted (implicit or explicit) between different data type, which would lose some precision, so the result cannot match each other as thought. Here I would like to gave a work around solution to solve the problem which the developers met. -- Declare and loop DECLARE @Intveral INT, @CurDate DATETIMEOFFSET; CREATE TABLE #TimeTable (FirstDate DATETIME, LastDate DATETIME2, GlobalDate DATETIMEOFFSET) SET @Intveral = 10000 WHILE (@Intveral > 0) BEGIN ----SET @CurDate = SYSDATETIMEOFFSET(); -- higher precision for future use only SET @CurDate = TODATETIMEOFFSET(GETDATE(),DATEDIFF(N,GETUTCDATE(),GETDATE())); -- lower precision to match exited date process INSERT #TimeTable (FirstDate, LastDate, GlobalDate) VALUES (@CurDate, @CurDate, @CurDate) SET @Intveral = @Intveral - 1 END GO -- Distinct Values SELECT COUNT(DISTINCT FirstDate) D_DATETIME, COUNT(DISTINCT LastDate) D_DATETIME2, COUNT(DISTINCT GlobalDate) D_SYSGETDATE FROM #TimeTable GO -- Join SELECT DISTINCT a.FirstDate,b.LastDate, b.GlobalDate, CAST(b.GlobalDate AS DATETIME) GlobalDateASDateTime FROM #TimeTable a INNER JOIN #TimeTable b ON a.FirstDate = CAST(b.GlobalDate AS DATETIME) GO -- Select SELECT * FROM #TimeTable GO -- Clean up DROP TABLE #TimeTable GO If you read my blog SQL SERVER – Difference Between DATETIME and DATETIME2 you will notice that I have achieved the same using GETDATE(). Are you using DATETIME2 in your production environment? If yes, I am interested to know the use case. Reference: Pinal Dave (http://www.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL DateTime, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Windows 8: Is Internet Explorer10 Metro mode disabled? Here is the fix.

    - by Gopinath
    Are you having issues with Internet Explorer 10 on Windows 8? Is Internet Explorer 10 application not launching in Metro mode and always launching in Desktop mode? Continue reading the post to understand and fix the problem. When Internet Explorer 10 does not launch in Metro mode? On Windows 8 when Internet Explorer is launched from Start screen it launches in Metro UI mode and when launched from Desktop it launches in traditional desktop UI mode. But when Internet Explorer  is not set as default browser, Windows 8 always launches Internet Explorer in Desktop mode irrespective of whether its launched from Start screen or Desktop. This generally happens when we install the browsers Firefox or Chrome and set them as default browser. How to restore Internet Explorer 10 Metro mode? The problem can be resolved by setting Internet Explorer 10 as the default web browser in Windows 8. But setting default web browser in Windows 8 is a bit tricky as there is no option available Options screen of  of Internet Explorer. To set Internet Explorer 10 as the default web browser follow these steps 1. Go to Start screen of Windows 8 and search for Default Programs app by typing Default using keyboard. 2. Click on the link Set your default programs 3. Choose Internet Explorer on the left section of the screen(pointer 1) and then click on the option Set this program as default available at the bottom right section(pointer 2) 4. That’s it. Now Internet Explorer is set as default web browser and from now onwards you will be able to launch Metro UI based Internet Explorer from Start screen

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  • Objective-C As A First OOP Language?

    - by Daniel Scocco
    I am just finishing the second semester of my CS degree. So far I learned C, all the fundamental algorithms and data structures (e.g., searching, sorting, linked lists, heaps, hash tables, trees, graphs, etc). Next year we'll start with OOP, using either Java or C++. Recently I got some ideas for some iPhone apps and got itchy to start working on them. However I heard some bad things about Objectice-C in the past, so I am wondering if learning it as my first OOP language could be a problem. Not to mention that I think it will be hard to find books/online courses that teach basic OOP concepts using Objective-C to illustrate the concepts (as opposed to books using Java or C++, which are plenty), so this could be another problem. In summary: should I start learning Objective-C and OOP concepts right now by my own, or wait one more semester until I learn Java/C++ at university and then jump into Objective-C? Update: For those interested in getting started with OOP via Objective-C I just found some nice tutorials inside Apple's Developer Library - http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/OOP_ObjC/Introduction/Introduction.html

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  • DirectX Unproject troubles

    - by pivotnig
    I have an orthographic projection and I try to unproject a point from screen space. Following are the view and projection matrices: var w2 = ScreenWidthInPixels/2; var h2 = ScreenHeightInPixels/2; view = Matrix.LookAtLH(new Vector3(0, 0, -1), new Vector3(0, 0, 0), Vector3.UnitY); proj = Matrix.OrthoOffCenterLH(-w2, w2, -h2, h2, 0.1f, 10f); Here is how I unproject a Point p, the point is given in screen pixels: var m = Vector3.Unproject(p, 0, 0, ScreenWidthInPixels, ScreenHeightInPixels, 0.1f, 10f, // znear and zfar view *proj); My code doesn't work, the matrix m contains only Nan. When I try to invert view * proj I get back a Matrix with only zeros. So I suspect my problem has something to do with the orthographic projection matrix. Here are my questions: Could the problem be caused by an underflow due to the large values in the OrthoOffCenterLH projection? What parameters do I have to pass for x,y,width,height in Unproject(...)? What significance has the minZ and maxZ parameter in Unproject(...)? Does it matter what I pass for p.Z in Unproject(...)?

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  • Debugging JuniperSetupClientInstaller.exe Problems

    - by Damon
    I recently moved from Windows 7 to Windows 2008 server so I can run SharePoint on my physical machine and not through a VPC, so I've been trying to get everything re-installed on my system.  As part of that process, I tried re-establishing a connection back to one of client's corporate networks and their system prompted me to run JuniperSetupClientInstaller.exe.  Normally this runs, finishes, and you can connect to the VPN no problem.  This time, however, it failed.  Unfortunately, there were no error messages to let me know why - it just didn't work. I've had success running application in "compatability mode" so I gave that a shot - same problem.  But during the installation I noticed that JuniperSetupClientInstaller.exe unpacks a number of files into a directory (you can see the exact location in the details of the installer) and then runs a DIFFERENT application - JuniperSetupClient.exe.  If you navigate to that directory, you will see a text file named JuniperSetupClient.log that contains information about the setup process. In my case, I installed a SharePoint site on Port 3333 - which the Juniper software needs to communicate with the VPN.  There was a nice message in the log file saying the VPN software could not bind to port 3333 which quickly alerted me to the issue, and moving the site off that port number fixed the issue.  However, it would have been nice to had an error message of sorts because I spent a chunk of time futilely researching compatibility issues. 

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  • Arduino IDE not connecting to microcontroller

    - by JDD
    I get this error when trying to connect to an Arduino through a USB serial connection. I'm using the Arduino IDE 1.0.1 and the 64bit version of Ubuntu 12.04. This has been a reoccurring problem since 10.04 and happens to a few other programs that use a serial connection too. I have no problem getting serial data from the Arduino using Python or Screen. The Arduino IDE seems to work just fine otherwise. processing.app.SerialException: Error opening serial port '/dev/ttyACM0'. at processing.app.Serial.<init>(Serial.java:178) at processing.app.Serial.<init>(Serial.java:92) at processing.app.SerialMonitor.openSerialPort(SerialMonitor.java:207) at processing.app.Editor.handleSerial(Editor.java:2447) at processing.app.EditorToolbar.mousePressed(EditorToolbar.java:353) at java.awt.Component.processMouseEvent(Component.java:6386) at javax.swing.JComponent.processMouseEvent(JComponent.java:3268) at java.awt.Component.processEvent(Component.java:6154) at java.awt.Container.processEvent(Container.java:2045) at java.awt.Component.dispatchEventImpl(Component.java:4750) at java.awt.Container.dispatchEventImpl(Container.java:2103) at java.awt.Component.dispatchEvent(Component.java:4576) at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4633) at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4294) at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4227) at java.awt.Container.dispatchEventImpl(Container.java:2089) at java.awt.Window.dispatchEventImpl(Window.java:2518) at java.awt.Component.dispatchEvent(Component.java:4576) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:672) at java.awt.EventQueue.access$400(EventQueue.java:96) at java.awt.EventQueue$2.run(EventQueue.java:631) at java.awt.EventQueue$2.run(EventQueue.java:629) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:105) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:116) at java.awt.EventQueue$3.run(EventQueue.java:645) at java.awt.EventQueue$3.run(EventQueue.java:643) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:105) at java.awt.EventQueue.dispatchEvent(EventQueue.java:642) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:275) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:200) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:190) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:185) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:177) at java.awt.EventDispatchThread.run(EventDispatchThread.java:138) Caused by: gnu.io.UnsupportedCommOperationException: Invalid Parameter at gnu.io.RXTXPort.setSerialPortParams(RXTXPort.java:171) at processing.app.Serial.<init>(Serial.java:163) ... 35 more

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  • Skinning af:selectOneChoice

    - by Duncan Mills
    A question came in today about how to skin the selection button ()  of an <af:selectOneChoice>. If you have a delve in the ADF Skinning editor, you'll find that there are selectors for the selectOneChoice when in compact mode (af|selectOneChoice::compact-dropdown-icon-style), however, there is not a selector for the icon in the "normal" mode. I had a quick delve into the skinning source files that you can find in the adf-richclient-impl-11.jar and likewise there seemed to be no association there. However, a quick sample page and a peek with Chrome developer tools revealed the problem.  The af:selectOneChoice gets rendered in the browser as a good old <select> element (reasonable enough!). Herein lies the problem, and the reason why there is no skin selector. The <select> HTML element does not have a standard way of replacing the image used for the dropdown button.  If you have a search around with your favorite search engine, you can find various workarounds and solutions for this.  For example, using Chrome and Safari you can define the following for the select element: select {   -webkit-appearance: listbox;   background-image: url(blob.png);    background-position: center right;   background-repeat: no-repeat;   } Which gives a very exciting select box:  .

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  • How do I create statistics to make ‘small’ objects appear ‘large’ to the Optmizer?

    - by Maria Colgan
    I recently spoke with a customer who has a development environment that is a tiny fraction of the size of their production environment. His team has been tasked with identifying problem SQL statements in this development environment before new code is released into production. The problem is the objects in the development environment are so small, the execution plans selected in the development environment rarely reflects what actually happens in production. To ensure the development environment accurately reflects production, in the eyes of the Optimizer, the statistics used in the development environment must be the same as the statistics used in production. This can be achieved by exporting the statistics from production and import them into the development environment. Even though the underlying objects are a fraction of the size of production, the Optimizer will see them as the same size and treat them the same way as it would in production. Below are the necessary steps to achieve this in their environment. I am using the SH sample schema as the application schema who's statistics we want to move from production to development. Step 1. Create a staging table, in the production environment, where the statistics can be stored Step 2. Export the statistics for the application schema, from the data dictionary in production, into the staging table Step 3. Create an Oracle directory on the production system where the export of the staging table will reside and grant the SH user the necessary privileges on it. Step 4. Export the staging table from production using data pump export Step 5. Copy the dump file containing the stating table from production to development Step 6. Create an Oracle directory on the development system where the export of the staging table resides and grant the SH user the necessary privileges on it.  Step 7. Import the staging table into the development environment using data pump import Step 8. Import the statistics from the staging table into the dictionary in the development environment. You can get a copy of the script I used to generate this post here. +Maria Colgan

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  • Anti-Forgery Request Recipes For ASP.NET MVC And AJAX

    - by Dixin
    Background To secure websites from cross-site request forgery (CSRF, or XSRF) attack, ASP.NET MVC provides an excellent mechanism: The server prints tokens to cookie and inside the form; When the form is submitted to server, token in cookie and token inside the form are sent in the HTTP request; Server validates the tokens. To print tokens to browser, just invoke HtmlHelper.AntiForgeryToken():<% using (Html.BeginForm()) { %> <%: this.Html.AntiForgeryToken(Constants.AntiForgeryTokenSalt)%> <%-- Other fields. --%> <input type="submit" value="Submit" /> <% } %> This invocation generates a token then writes inside the form:<form action="..." method="post"> <input name="__RequestVerificationToken" type="hidden" value="J56khgCvbE3bVcsCSZkNVuH9Cclm9SSIT/ywruFsXEgmV8CL2eW5C/gGsQUf/YuP" /> <!-- Other fields. --> <input type="submit" value="Submit" /> </form> and also writes into the cookie: __RequestVerificationToken_Lw__= J56khgCvbE3bVcsCSZkNVuH9Cclm9SSIT/ywruFsXEgmV8CL2eW5C/gGsQUf/YuP When the above form is submitted, they are both sent to server. In the server side, [ValidateAntiForgeryToken] attribute is used to specify the controllers or actions to validate them:[HttpPost] [ValidateAntiForgeryToken(Salt = Constants.AntiForgeryTokenSalt)] public ActionResult Action(/* ... */) { // ... } This is very productive for form scenarios. But recently, when resolving security vulnerabilities for Web products, some problems are encountered. Specify validation on controller (not on each action) The server side problem is, It is expected to declare [ValidateAntiForgeryToken] on controller, but actually it has be to declared on each POST actions. Because POST actions are usually much more then controllers, the work would be a little crazy. Problem Usually a controller contains actions for HTTP GET and actions for HTTP POST requests, and usually validations are expected for HTTP POST requests. So, if the [ValidateAntiForgeryToken] is declared on the controller, the HTTP GET requests become invalid:[ValidateAntiForgeryToken(Salt = Constants.AntiForgeryTokenSalt)] public class SomeController : Controller // One [ValidateAntiForgeryToken] attribute. { [HttpGet] public ActionResult Index() // Index() cannot work. { // ... } [HttpPost] public ActionResult PostAction1(/* ... */) { // ... } [HttpPost] public ActionResult PostAction2(/* ... */) { // ... } // ... } If browser sends an HTTP GET request by clicking a link: http://Site/Some/Index, validation definitely fails, because no token is provided. So the result is, [ValidateAntiForgeryToken] attribute must be distributed to each POST action:public class SomeController : Controller // Many [ValidateAntiForgeryToken] attributes. { [HttpGet] public ActionResult Index() // Works. { // ... } [HttpPost] [ValidateAntiForgeryToken(Salt = Constants.AntiForgeryTokenSalt)] public ActionResult PostAction1(/* ... */) { // ... } [HttpPost] [ValidateAntiForgeryToken(Salt = Constants.AntiForgeryTokenSalt)] public ActionResult PostAction2(/* ... */) { // ... } // ... } This is a little bit crazy, because one application can have a lot of POST actions. Solution To avoid a large number of [ValidateAntiForgeryToken] attributes (one for each POST action), the following ValidateAntiForgeryTokenWrapperAttribute wrapper class can be helpful, where HTTP verbs can be specified:[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = false, Inherited = true)] public class ValidateAntiForgeryTokenWrapperAttribute : FilterAttribute, IAuthorizationFilter { private readonly ValidateAntiForgeryTokenAttribute _validator; private readonly AcceptVerbsAttribute _verbs; public ValidateAntiForgeryTokenWrapperAttribute(HttpVerbs verbs) : this(verbs, null) { } public ValidateAntiForgeryTokenWrapperAttribute(HttpVerbs verbs, string salt) { this._verbs = new AcceptVerbsAttribute(verbs); this._validator = new ValidateAntiForgeryTokenAttribute() { Salt = salt }; } public void OnAuthorization(AuthorizationContext filterContext) { string httpMethodOverride = filterContext.HttpContext.Request.GetHttpMethodOverride(); if (this._verbs.Verbs.Contains(httpMethodOverride, StringComparer.OrdinalIgnoreCase)) { this._validator.OnAuthorization(filterContext); } } } When this attribute is declared on controller, only HTTP requests with the specified verbs are validated:[ValidateAntiForgeryTokenWrapper(HttpVerbs.Post, Constants.AntiForgeryTokenSalt)] public class SomeController : Controller { // GET actions are not affected. // Only HTTP POST requests are validated. } Now one single attribute on controller turns on validation for all POST actions. Maybe it would be nice if HTTP verbs can be specified on the built-in [ValidateAntiForgeryToken] attribute, which is easy to implemented. Specify Non-constant salt in runtime By default, the salt should be a compile time constant, so it can be used for the [ValidateAntiForgeryToken] or [ValidateAntiForgeryTokenWrapper] attribute. Problem One Web product might be sold to many clients. If a constant salt is evaluated in compile time, after the product is built and deployed to many clients, they all have the same salt. Of course, clients do not like this. Even some clients might want to specify a custom salt in configuration. In these scenarios, salt is required to be a runtime value. Solution In the above [ValidateAntiForgeryToken] and [ValidateAntiForgeryTokenWrapper] attribute, the salt is passed through constructor. So one solution is to remove this parameter:public class ValidateAntiForgeryTokenWrapperAttribute : FilterAttribute, IAuthorizationFilter { public ValidateAntiForgeryTokenWrapperAttribute(HttpVerbs verbs) { this._verbs = new AcceptVerbsAttribute(verbs); this._validator = new ValidateAntiForgeryTokenAttribute() { Salt = AntiForgeryToken.Value }; } // Other members. } But here the injected dependency becomes a hard dependency. So the other solution is moving validation code into controller to work around the limitation of attributes:public abstract class AntiForgeryControllerBase : Controller { private readonly ValidateAntiForgeryTokenAttribute _validator; private readonly AcceptVerbsAttribute _verbs; protected AntiForgeryControllerBase(HttpVerbs verbs, string salt) { this._verbs = new AcceptVerbsAttribute(verbs); this._validator = new ValidateAntiForgeryTokenAttribute() { Salt = salt }; } protected override void OnAuthorization(AuthorizationContext filterContext) { base.OnAuthorization(filterContext); string httpMethodOverride = filterContext.HttpContext.Request.GetHttpMethodOverride(); if (this._verbs.Verbs.Contains(httpMethodOverride, StringComparer.OrdinalIgnoreCase)) { this._validator.OnAuthorization(filterContext); } } } Then make controller classes inheriting from this AntiForgeryControllerBase class. Now the salt is no long required to be a compile time constant. Submit token via AJAX For browser side, once server side turns on anti-forgery validation for HTTP POST, all AJAX POST requests will fail by default. Problem In AJAX scenarios, the HTTP POST request is not sent by form. Take jQuery as an example:$.post(url, { productName: "Tofu", categoryId: 1 // Token is not posted. }, callback); This kind of AJAX POST requests will always be invalid, because server side code cannot see the token in the posted data. Solution Basically, the tokens must be printed to browser then sent back to server. So first of all, HtmlHelper.AntiForgeryToken() need to be called somewhere. Now the browser has token in both HTML and cookie. Then jQuery must find the printed token in the HTML, and append token to the data before sending:$.post(url, { productName: "Tofu", categoryId: 1, __RequestVerificationToken: getToken() // Token is posted. }, callback); To be reusable, this can be encapsulated into a tiny jQuery plugin:/// <reference path="jquery-1.4.2.js" /> (function ($) { $.getAntiForgeryToken = function (tokenWindow, appPath) { // HtmlHelper.AntiForgeryToken() must be invoked to print the token. tokenWindow = tokenWindow && typeof tokenWindow === typeof window ? tokenWindow : window; appPath = appPath && typeof appPath === "string" ? "_" + appPath.toString() : ""; // The name attribute is either __RequestVerificationToken, // or __RequestVerificationToken_{appPath}. tokenName = "__RequestVerificationToken" + appPath; // Finds the <input type="hidden" name={tokenName} value="..." /> from the specified. // var inputElements = $("input[type='hidden'][name='__RequestVerificationToken" + appPath + "']"); var inputElements = tokenWindow.document.getElementsByTagName("input"); for (var i = 0; i < inputElements.length; i++) { var inputElement = inputElements[i]; if (inputElement.type === "hidden" && inputElement.name === tokenName) { return { name: tokenName, value: inputElement.value }; } } return null; }; $.appendAntiForgeryToken = function (data, token) { // Converts data if not already a string. if (data && typeof data !== "string") { data = $.param(data); } // Gets token from current window by default. token = token ? token : $.getAntiForgeryToken(); // $.getAntiForgeryToken(window). data = data ? data + "&" : ""; // If token exists, appends {token.name}={token.value} to data. return token ? data + encodeURIComponent(token.name) + "=" + encodeURIComponent(token.value) : data; }; // Wraps $.post(url, data, callback, type). $.postAntiForgery = function (url, data, callback, type) { return $.post(url, $.appendAntiForgeryToken(data), callback, type); }; // Wraps $.ajax(settings). $.ajaxAntiForgery = function (settings) { settings.data = $.appendAntiForgeryToken(settings.data); return $.ajax(settings); }; })(jQuery); In most of the scenarios, it is Ok to just replace $.post() invocation with $.postAntiForgery(), and replace $.ajax() with $.ajaxAntiForgery():$.postAntiForgery(url, { productName: "Tofu", categoryId: 1 }, callback); // Token is posted. There might be some scenarios of custom token, where $.appendAntiForgeryToken() is useful:data = $.appendAntiForgeryToken(data, token); // Token is already in data. No need to invoke $.postAntiForgery(). $.post(url, data, callback); And there are scenarios that the token is not in the current window. For example, an HTTP POST request can be sent by an iframe, while the token is in the parent window. Here, token's container window can be specified for $.getAntiForgeryToken():data = $.appendAntiForgeryToken(data, $.getAntiForgeryToken(window.parent)); // Token is already in data. No need to invoke $.postAntiForgery(). $.post(url, data, callback); If you have better solution, please do tell me.

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  • Triple boot vista xp ubuntu

    - by Artyom2033
    My partition table is pretty messed up from install/uninstall os and what I want to do now is to clear that and have vista/xp/ubuntu 12.04 on the same hard drive. I have create a new partition for xp on vista, everything was fine, but when I restarted my pc, I was getting the grub restore prompt. Even when I was trying to install xp, when the 'lunch windows' came, a wild BSOD appear. So I have deleted my partition for xp using gParted include in the 12.04 live cd. This haven't resolve the problem and I am still unable to boot in vista nor ubuntu. But I realy what this triple boot for LoL purpose (since my vista installation keep giving latency spike in this game and I hope this will not be the case in a fresh xp installation (I have tested it in ubuntu, the ping was good, but the fps wasn't). So what I want to do, is to install xp on a partition, then be able to boot on any of them without a problem from a nice installation of grub or something. gParted screenshot Thanks for help. Sorry for my English.

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  • C# Neural Networks with Encog

    - by JoshReuben
    Neural Networks ·       I recently read a book Introduction to Neural Networks for C# , by Jeff Heaton. http://www.amazon.com/Introduction-Neural-Networks-C-2nd/dp/1604390093/ref=sr_1_2?ie=UTF8&s=books&qid=1296821004&sr=8-2-spell. Not the 1st ANN book I've perused, but a nice revision.   ·       Artificial Neural Networks (ANNs) are a mechanism of machine learning – see http://en.wikipedia.org/wiki/Artificial_neural_network , http://en.wikipedia.org/wiki/Category:Machine_learning ·       Problems Not Suited to a Neural Network Solution- Programs that are easily written out as flowcharts consisting of well-defined steps, program logic that is unlikely to change, problems in which you must know exactly how the solution was derived. ·       Problems Suited to a Neural Network – pattern recognition, classification, series prediction, and data mining. Pattern recognition - network attempts to determine if the input data matches a pattern that it has been trained to recognize. Classification - take input samples and classify them into fuzzy groups. ·       As far as machine learning approaches go, I thing SVMs are superior (see http://en.wikipedia.org/wiki/Support_vector_machine ) - a neural network has certain disadvantages in comparison: an ANN can be overtrained, different training sets can produce non-deterministic weights and it is not possible to discern the underlying decision function of an ANN from its weight matrix – they are black box. ·       In this post, I'm not going to go into internals (believe me I know them). An autoassociative network (e.g. a Hopfield network) will echo back a pattern if it is recognized. ·       Under the hood, there is very little maths. In a nutshell - Some simple matrix operations occur during training: the input array is processed (normalized into bipolar values of 1, -1) - transposed from input column vector into a row vector, these are subject to matrix multiplication and then subtraction of the identity matrix to get a contribution matrix. The dot product is taken against the weight matrix to yield a boolean match result. For backpropogation training, a derivative function is required. In learning, hill climbing mechanisms such as Genetic Algorithms and Simulated Annealing are used to escape local minima. For unsupervised training, such as found in Self Organizing Maps used for OCR, Hebbs rule is applied. ·       The purpose of this post is not to mire you in technical and conceptual details, but to show you how to leverage neural networks via an abstraction API - Encog   Encog ·       Encog is a neural network API ·       Links to Encog: http://www.encog.org , http://www.heatonresearch.com/encog, http://www.heatonresearch.com/forum ·       Encog requires .Net 3.5 or higher – there is also a Silverlight version. Third-Party Libraries – log4net and nunit. ·       Encog supports feedforward, recurrent, self-organizing maps, radial basis function and Hopfield neural networks. ·       Encog neural networks, and related data, can be stored in .EG XML files. ·       Encog Workbench allows you to edit, train and visualize neural networks. The Encog Workbench can generate code. Synapses and layers ·       the primary building blocks - Almost every neural network will have, at a minimum, an input and output layer. In some cases, the same layer will function as both input and output layer. ·       To adapt a problem to a neural network, you must determine how to feed the problem into the input layer of a neural network, and receive the solution through the output layer of a neural network. ·       The Input Layer - For each input neuron, one double value is stored. An array is passed as input to a layer. Encog uses the interface INeuralData to hold these arrays. The class BasicNeuralData implements the INeuralData interface. Once the neural network processes the input, an INeuralData based class will be returned from the neural network's output layer. ·       convert a double array into an INeuralData object : INeuralData data = new BasicNeuralData(= new double[10]); ·       the Output Layer- The neural network outputs an array of doubles, wraped in a class based on the INeuralData interface. ·        The real power of a neural network comes from its pattern recognition capabilities. The neural network should be able to produce the desired output even if the input has been slightly distorted. ·       Hidden Layers– optional. between the input and output layers. very much a “black box”. If the structure of the hidden layer is too simple it may not learn the problem. If the structure is too complex, it will learn the problem but will be very slow to train and execute. Some neural networks have no hidden layers. The input layer may be directly connected to the output layer. Further, some neural networks have only a single layer. A single layer neural network has the single layer self-connected. ·       connections, called synapses, contain individual weight matrixes. These values are changed as the neural network learns. Constructing a Neural Network ·       the XOR operator is a frequent “first example” -the “Hello World” application for neural networks. ·       The XOR Operator- only returns true when both inputs differ. 0 XOR 0 = 0 1 XOR 0 = 1 0 XOR 1 = 1 1 XOR 1 = 0 ·       Structuring a Neural Network for XOR  - two inputs to the XOR operator and one output. ·       input: 0.0,0.0 1.0,0.0 0.0,1.0 1.0,1.0 ·       Expected output: 0.0 1.0 1.0 0.0 ·       A Perceptron - a simple feedforward neural network to learn the XOR operator. ·       Because the XOR operator has two inputs and one output, the neural network will follow suit. Additionally, the neural network will have a single hidden layer, with two neurons to help process the data. The choice for 2 neurons in the hidden layer is arbitrary, and often comes down to trial and error. ·       Neuron Diagram for the XOR Network ·       ·       The Encog workbench displays neural networks on a layer-by-layer basis. ·       Encog Layer Diagram for the XOR Network:   ·       Create a BasicNetwork - Three layers are added to this network. the FinalizeStructure method must be called to inform the network that no more layers are to be added. The call to Reset randomizes the weights in the connections between these layers. var network = new BasicNetwork(); network.AddLayer(new BasicLayer(2)); network.AddLayer(new BasicLayer(2)); network.AddLayer(new BasicLayer(1)); network.Structure.FinalizeStructure(); network.Reset(); ·       Neural networks frequently start with a random weight matrix. This provides a starting point for the training methods. These random values will be tested and refined into an acceptable solution. However, sometimes the initial random values are too far off. Sometimes it may be necessary to reset the weights again, if training is ineffective. These weights make up the long-term memory of the neural network. Additionally, some layers have threshold values that also contribute to the long-term memory of the neural network. Some neural networks also contain context layers, which give the neural network a short-term memory as well. The neural network learns by modifying these weight and threshold values. ·       Now that the neural network has been created, it must be trained. Training a Neural Network ·       construct a INeuralDataSet object - contains the input array and the expected output array (of corresponding range). Even though there is only one output value, we must still use a two-dimensional array to represent the output. public static double[][] XOR_INPUT ={ new double[2] { 0.0, 0.0 }, new double[2] { 1.0, 0.0 }, new double[2] { 0.0, 1.0 }, new double[2] { 1.0, 1.0 } };   public static double[][] XOR_IDEAL = { new double[1] { 0.0 }, new double[1] { 1.0 }, new double[1] { 1.0 }, new double[1] { 0.0 } };   INeuralDataSet trainingSet = new BasicNeuralDataSet(XOR_INPUT, XOR_IDEAL); ·       Training is the process where the neural network's weights are adjusted to better produce the expected output. Training will continue for many iterations, until the error rate of the network is below an acceptable level. Encog supports many different types of training. Resilient Propagation (RPROP) - general-purpose training algorithm. All training classes implement the ITrain interface. The RPROP algorithm is implemented by the ResilientPropagation class. Training the neural network involves calling the Iteration method on the ITrain class until the error is below a specific value. The code loops through as many iterations, or epochs, as it takes to get the error rate for the neural network to be below 1%. Once the neural network has been trained, it is ready for use. ITrain train = new ResilientPropagation(network, trainingSet);   for (int epoch=0; epoch < 10000; epoch++) { train.Iteration(); Debug.Print("Epoch #" + epoch + " Error:" + train.Error); if (train.Error > 0.01) break; } Executing a Neural Network ·       Call the Compute method on the BasicNetwork class. Console.WriteLine("Neural Network Results:"); foreach (INeuralDataPair pair in trainingSet) { INeuralData output = network.Compute(pair.Input); Console.WriteLine(pair.Input[0] + "," + pair.Input[1] + ", actual=" + output[0] + ",ideal=" + pair.Ideal[0]); } ·       The Compute method accepts an INeuralData class and also returns a INeuralData object. Neural Network Results: 0.0,0.0, actual=0.002782538818034049,ideal=0.0 1.0,0.0, actual=0.9903741937121177,ideal=1.0 0.0,1.0, actual=0.9836807956566187,ideal=1.0 1.0,1.0, actual=0.0011646072586172778,ideal=0.0 ·       the network has not been trained to give the exact results. This is normal. Because the network was trained to 1% error, each of the results will also be within generally 1% of the expected value.

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  • Cannot connect my Ubuntu to TV with HDMI

    - by Hannes Johannes
    Another problem in my way to Ubuntu world.. Trying to make things work Linux way, day 4, problem #5321: I have a Compaq laptop and Nvidia graphic adapter. I also have Panasonic TV, which I thought I could use as a second screen just like I used to to when I was still using Windows Vista with my laptop. Plug the screen to the comp and voilá, I can watch my videos on big screen. And a boll***s I can, not with ubuntu anyways. Nvidia x server (or whatever it's called) does recognize my tv. It's very badly designed gui as I can never be sure has it saved my changes or not (most often not), but I recon I've got that one sorted out. I haven't found a way to set a primary monitor there, but it does see there are two monitors, my laptop and the tv. So far so good. But then? Ubuntu's own monitor setting only sees the laptop screen. If I reboot (with the HDMI cable connected) I end up having a black screen. Then I have to take the cable away, cut the power off and restart the comp.. Please, help, any help would be appreciated! I would so much love to like this linux more than windows but it surely takes a lot of trying...

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  • We Don’t Need No Regions

    - by João Angelo
    If your code reaches a level where you want to hide it behind regions then you have a problem that regions won’t solve. Regions are good to hide things that you don’t want to have knowledge about such as auto-generated code. Normally, when you’re developing you end up reading more code than you write it so why would you want to complicate the reading process. I, for one, would love to have that one discussion around regions where someone convinces me that they solve a problem that has no other alternative solution, but I’m still waiting. The most frequent argument I hear about regions is that they allow you to structure your code, but why don’t just structure it using classes, methods and all that other stuff that OOP is about because at the end of the day, you should be doing object oriented programming and not region oriented programming. Having said that, I do believe that sometimes is helpful to have a quick overview of a code file contents and Visual Studio allows you to do just that through the Collapse to Definitions command (CTRL + M, CTRL + O) which collapses the members of all types; if you like regions, you should try this, it is much more useful to read all the members of a type than all the regions inside a type.

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  • Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E

    - by Sebastian Bugiu
    I had Ubuntu 11.10 and in the last few weeks I experienced an obscure problem: after I had the computer running for a few days I could no longer connect to google.com or anything related to google. All sites worked with all browsers (Firefox, chrome, opera) except google. It remained in the connecting phase for a few minutes and either timed out or finally connected with this huge delay. Even if I entered other sites such as this one, if it had anything to do with google such adsense or gstatic or whatever with g in it, that site took a long time to load waiting in connecting to gstatic.com . Anything google related took minutes to work, but everything else worked instantly! I tried rebooting or using other machine(with windows on it) and this worked, so it's not network related. But after a few days it started not working again... So I upgraded to the Precise Pangolin hoping this behavior would go away. It didn't! After a few days I get the same behavior as in 11.10. What am I supposed to do? Reboot every other day? I didn't have this problem with neither 10.10 or 11.04. I found the Realtek RTL8168/8111E issue with the r8169 driver but this is not exactly the same card so probably trying r8168 won't help. Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 02) Subsystem: Toshiba America Info Systems Device ff1c Flags: bus master, fast devsel, latency 0, IRQ 44 I/O ports at 4000 [size=256] Memory at d0010000 (64-bit, prefetchable) [size=4K] Memory at d0000000 (64-bit, prefetchable) [size=64K] Capabilities: [40] Power Management version 7 Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+ Capabilities: [70] Express Endpoint, MSI 01 Capabilities: [ac] MSI-X: Enable- Count=2 Masked- Capabilities: [cc] Vital Product Data Capabilities: [100] Advanced Error Reporting Capabilities: [140] Virtual Channel Capabilities: [160] Device Serial Number 09-00-00-00-ff-ff-00-00 Kernel driver in use: r8169 Kernel modules: r8169

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