Search Results

Search found 12824 results on 513 pages for 'glen little'.

Page 162/513 | < Previous Page | 158 159 160 161 162 163 164 165 166 167 168 169 | Next Page >

ASP.NET MVC JavaScript Routing

- by zowens

Have you ever done this sort of thing in your ASP.NET MVC view? The weird thing about this isn’t the alert function, it’s the code block containing the Url formation using the ASP.NET MVC UrlHelper. The terrible thing about this experience is the obvious lack of IntelliSense and this ugly inline JavaScript code. Inline JavaScript isn’t portable to other pages beyond the current page of execution. It is generally considered bad practice to use inline JavaScript in your public-facing pages. How ludicrous would it be to copy and paste the entire jQuery code base into your pages…? Not something you’d ever consider doing. The problem is that your URLs have to be generated by ASP.NET at runtime and really can’t be copied to your JavaScript code without some trickery. How about this? Does the hard-coded URL bother you? It really bothers me. The typical solution to this whole routing in JavaScript issue is to just hard-code your URLs into your JavaScript files and call it done. But what if your URLs change? You have to now go an track down the places in JavaScript and manually replace them. What if you get the pattern wrong? Do you have tests around it? This isn’t something you should have to worry about. The Solution To Our Problems The solution is to port routing over to JavaScript. Does that sound daunting to you? It’s actually not very hard, but I decided to create my own generator that will do all the work for you. What I have created is a very basic port of the route formation feature of ASP.NET routing. It will generate the formatted URLs based on your routing patterns. Here’s how you’d do this: Does that feel familiar? It looks a lot like something you’d do inside of your ASP.NET MVC views… but this is inside of a JavaScript file… just a plain ol’ .js file. Your first question might be why do you have to have that “.toUrl()” thing. The reason is that I wanted to make POST and GET requests dead simple. Here’s how you’d do a POST request (and the same would work with a GET request): The first parameter is extra data passed to the post request and the second parameter is a function that handles the success of the POST request. If you’re familiar with jQuery’s Ajax goodness, you’ll know how to use it. (if not, check out http://api.jquery.com/jQuery.Post/ and the parameters are essentially the same). But we still haven’t gotten rid of the magic strings. We still have controller names and action names represented as strings. This is going to blow your mind… If you’ve seen T4MVC, this will look familiar. We’re essentially doing the same sort of thing with my JavaScript router, but we’re porting the concept to JavaScript. The good news is that parameters to the controllers are directly reflected in the action function, just like T4MVC. And the even better news… IntlliSense is easily transferred to the JavaScript version if you’re using Visual Studio as your JavaScript editor. The additional data parameter gives you the ability to pass extra routing data to the URL formatter. About the Magic You may be wondering how this all work. It’s actually quite simple. I’ve built a simple jQuery pluggin (called routeManager) that hangs off the main jQuery namespace and routes all the URLs. Every time your solution builds, a routing file will be generated with this pluggin, all your route and controller definitions along with your documentation. Then by the power of Visual Studio, you get some really slick IntelliSense that is hard to live without. But there are a few steps you have to take before this whole thing is going to work. First and foremost, you need a reference to the JsRouting.Core.dll to your projects containing controllers or routes. Second, you have to specify your routes in a bit of a non-standard way. See, we can’t just pull routes out of your App_Start in your Global.asax. We force you to build a route source like this: The way we determine the routes is by pulling in all RouteSources and generating routes based upon the mapped routes. There are various reasons why we can’t use RouteCollection (different post for another day)… but in this case, you get the same route mapping experience. Converting the RouteSource to a RouteCollection is trivial (there’s an extension method for that). Next thing you have to do is generate a documentation XML file. This is done by going to the project settings, going to the build tab and clicking the checkbox. (this isn’t required, but nice to have). The final thing you need to do is hook up the generation mechanism. Pop open your project file and look for the AfterBuild step. Now change the build step task to look like this: The “PathToOutputExe” is the path to the JsRouting.Output.exe file. This will change based on where you put the EXE. The “PathToOutputJs” is a path to the output JavaScript file. The “DicrectoryOfAssemblies” is a path to the directory containing controller and routing DLLs. The JsRouting.Output.exe executable pulls in all these assemblies and scans them for controllers and route sources. Now that wasn’t too bad, was it :) The State of the Project This is definitely not complete… I have a lot of plans for this little project of mine. For starters, I need to look at the generation mechanism. Either I will be creating a utility that will do the project file manipulation or I will go a different direction. I’d like some feedback on this if you feel partial either way. Another thing I don’t support currently is areas. While this wouldn’t be too hard to support, I just don’t use areas and I wanted something up quickly (this is, after all, for a current project of mine). I’ll be adding support shortly. There are a few things that I haven’t covered in this post that I will most certainly be covering in another post, such as routing constraints and how these will be translated to JavaScript. I decided to open source this whole thing, since it’s a nice little utility I think others should really be using. Currently we’re using ASP.NET MVC 2, but it should work with MVC 3 as well. I’ll upgrade it as soon as MVC 3 is released. Along those same lines, I’m investigating how this could be put on the NuGet feed. Show me the Bits! OK, OK! The code is posted on my GitHub account. Go nuts. Tell me what you think. Tell me what you want. Tell me that you hate it. All feedback is welcome! https://github.com/zowens/ASP.NET-MVC-JavaScript-Routing

Read the article
C# Extension Methods - To Extend or Not To Extend...

- by James Michael Hare

I've been thinking a lot about extension methods lately, and I must admit I both love them and hate them. They are a lot like sugar, they taste so nice and sweet, but they'll rot your teeth if you eat them too much. I can't deny that they aren't useful and very handy. One of the major components of the Shared Component library where I work is a set of useful extension methods. But, I also can't deny that they tend to be overused and abused to willy-nilly extend every living type. So what constitutes a good extension method? Obviously, you can write an extension method for nearly anything whether it is a good idea or not. Many times, in fact, an idea seems like a good extension method but in retrospect really doesn't fit. So what's the litmus test? To me, an extension method should be like in the movies when a person runs into their twin, separated at birth. You just know you're related. Obviously, that's hard to quantify, so let's try to put a few rules-of-thumb around them. A good extension method should: Apply to any possible instance of the type it extends. Simplify logic and improve readability/maintainability. Apply to the most specific type or interface applicable. Be isolated in a namespace so that it does not pollute IntelliSense. So let's look at a few examples in relation to these rules. The first rule, to me, is the most important of all. Once again, it bears repeating, a good extension method should apply to all possible instances of the type it extends. It should feel like the long lost relative that should have been included in the original class but somehow was missing from the family tree. Take this nifty little int extension, I saw this once in a blog and at first I really thought it was pretty cool, but then I started noticing a code smell I couldn't quite put my finger on. So let's look: public static class IntExtensinos { public static int Seconds(int num) { return num * 1000; } public static int Minutes(int num) { return num * 60000; } } This is so you could do things like: ... Thread.Sleep(5.Seconds()); ... proxy.Timeout = 1.Minutes(); ... Awww, you say, that's cute! Well, that's the problem, it's kitschy and it doesn't always apply (and incidentally you could achieve the same thing with TimeStamp.FromSeconds(5)). It's syntactical candy that looks cool, but tends to rot and pollute the code. It would allow things like: total += numberOfTodaysOrders.Seconds(); which makes no sense and should never be allowed. The problem is you're applying an extension method to a logical domain, not a type domain. That is, the extension method Seconds() doesn't really apply to ALL ints, it applies to ints that are representative of time that you want to convert to milliseconds. Do you see what I mean? The two problems, in a nutshell, are that a) Seconds() called off a non-time value makes no sense and b) calling Seconds() off something to pass to something that does not take milliseconds will be off by a factor of 1000 or worse. Thus, in my mind, you should only ever have an extension method that applies to the whole domain of that type. For example, this is one of my personal favorites: public static bool IsBetween<T>(this T value, T low, T high) where T : IComparable<T> { return value.CompareTo(low) >= 0 && value.CompareTo(high) <= 0; } This allows you to check if any IComparable<T> is within an upper and lower bound. Think of how many times you type something like: if (response.Employee.Address.YearsAt >= 2 && response.Employee.Address.YearsAt <= 10) { ... } Now, you can instead type: if(response.Employee.Address.YearsAt.IsBetween(2, 10)) { ... } Note that this applies to all IComparable<T> -- that's ints, chars, strings, DateTime, etc -- and does not depend on any logical domain. In addition, it satisfies the second point and actually makes the code more readable and maintainable. Let's look at the third point. In it we said that an extension method should fit the most specific interface or type possible. Now, I'm not saying if you have something that applies to enumerables, you create an extension for List, Array, Dictionary, etc (though you may have reasons for doing so), but that you should beware of making things TOO general. For example, let's say we had an extension method like this: public static T ConvertTo<T>(this object value) { return (T)Convert.ChangeType(value, typeof(T)); } This lets you do more fluent conversions like: double d = "5.0".ConvertTo<double>(); However, if you dig into Reflector (LOVE that tool) you will see that if the type you are calling on does not implement IConvertible, what you convert to MUST be the exact type or it will throw an InvalidCastException. Now this may or may not be what you want in this situation, and I leave that up to you. Things like this would fail: object value = new Employee(); ... // class cast exception because typeof(IEmployee) != typeof(Employee) IEmployee emp = value.ConvertTo<IEmployee>(); Yes, that's a downfall of working with Convertible in general, but if you wanted your fluent interface to be more type-safe so that ConvertTo were only callable on IConvertibles (and let casting be a manual task), you could easily make it: public static T ConvertTo<T>(this IConvertible value) { return (T)Convert.ChangeType(value, typeof(T)); } This is what I mean by choosing the best type to extend. Consider that if we used the previous (object) version, every time we typed a dot ('.') on an instance we'd pull up ConvertTo() whether it was applicable or not. By filtering our extension method down to only valid types (those that implement IConvertible) we greatly reduce our IntelliSense pollution and apply a good level of compile-time correctness. Now my fourth rule is just my general rule-of-thumb. Obviously, you can make extension methods as in-your-face as you want. I included all mine in my work libraries in its own sub-namespace, something akin to: namespace Shared.Core.Extensions { ... } This is in a library called Shared.Core, so just referencing the Core library doesn't pollute your IntelliSense, you have to actually do a using on Shared.Core.Extensions to bring the methods in. This is very similar to the way Microsoft puts its extension methods in System.Linq. This way, if you want 'em, you use the appropriate namespace. If you don't want 'em, they won't pollute your namespace. To really make this work, however, that namespace should only include extension methods and subordinate types those extensions themselves may use. If you plant other useful classes in those namespaces, once a user includes it, they get all the extensions too. Also, just as a personal preference, extension methods that aren't simply syntactical shortcuts, I like to put in a static utility class and then have extension methods for syntactical candy. For instance, I think it imaginable that any object could be converted to XML: namespace Shared.Core { // A collection of XML Utility classes public static class XmlUtility { ... // Serialize an object into an xml string public static string ToXml(object input) { var xs = new XmlSerializer(input.GetType()); // use new UTF8Encoding here, not Encoding.UTF8. The later includes // the BOM which screws up subsequent reads, the former does not. using (var memoryStream = new MemoryStream()) using (var xmlTextWriter = new XmlTextWriter(memoryStream, new UTF8Encoding())) { xs.Serialize(xmlTextWriter, input); return Encoding.UTF8.GetString(memoryStream.ToArray()); } } ... } } I also wanted to be able to call this from an object like: value.ToXml(); But here's the problem, if i made this an extension method from the start with that one little keyword "this", it would pop into IntelliSense for all objects which could be very polluting. Instead, I put the logic into a utility class so that users have the choice of whether or not they want to use it as just a class and not pollute IntelliSense, then in my extensions namespace, I add the syntactical candy: namespace Shared.Core.Extensions { public static class XmlExtensions { public static string ToXml(this object value) { return XmlUtility.ToXml(value); } } } So now it's the best of both worlds. On one hand, they can use the utility class if they don't want to pollute IntelliSense, and on the other hand they can include the Extensions namespace and use as an extension if they want. The neat thing is it also adheres to the Single Responsibility Principle. The XmlUtility is responsible for converting objects to XML, and the XmlExtensions is responsible for extending object's interface for ToXml().

Read the article
T-SQL Tuesday #31 - Logging Tricks with CONTEXT_INFO

- by Most Valuable Yak (Rob Volk)

This month's T-SQL Tuesday is being hosted by Aaron Nelson [b | t], fellow Atlantan (the city in Georgia, not the famous sunken city, or the resort in the Bahamas) and covers the topic of logging (the recording of information, not the harvesting of trees) and maintains the fine T-SQL Tuesday tradition begun by Adam Machanic [b | t] (the SQL Server guru, not the guy who fixes cars, check the spelling again, there will be a quiz later). This is a trick I learned from Fernando Guerrero [b | t] waaaaaay back during the PASS Summit 2004 in sunny, hurricane-infested Orlando, during his session on Secret SQL Server (not sure if that's the correct title, and I haven't used parentheses in this paragraph yet). CONTEXT_INFO is a neat little feature that's existed since SQL Server 2000 and perhaps even earlier. It lets you assign data to the current session/connection, and maintains that data until you disconnect or change it. In addition to the CONTEXT_INFO() function, you can also query the context_info column in sys.dm_exec_sessions, or even sysprocesses if you're still running SQL Server 2000, if you need to see it for another session. While you're limited to 128 bytes, one big advantage that CONTEXT_INFO has is that it's independent of any transactions. If you've ever logged to a table in a transaction and then lost messages when it rolled back, you can understand how aggravating it can be. CONTEXT_INFO also survives across multiple SQL batches (GO separators) in the same connection, so for those of you who were going to suggest "just log to a table variable, they don't get rolled back": HA-HA, I GOT YOU! Since GO starts a new batch all variable declarations are lost. Here's a simple example I recently used at work. I had to test database mirroring configurations for disaster recovery scenarios and measure the network throughput. I also needed to log how long it took for the script to run and include the mirror settings for the database in question. I decided to use AdventureWorks as my database model, and Adam Machanic's Big Adventure script to provide a fairly large workload that's repeatable and easily scalable. My test would consist of several copies of AdventureWorks running the Big Adventure script while I mirrored the databases (or not). Since Adam's script contains several batches, I decided CONTEXT_INFO would have to be used. As it turns out, I only needed to grab the start time at the beginning, I could get the rest of the data at the end of the process. The code is pretty small: declare @time binary(128)=cast(getdate() as binary(8)) set context_info @time ... rest of Big Adventure code ... go use master; insert mirror_test(server,role,partner,db,state,safety,start,duration) select @@servername, mirroring_role_desc, mirroring_partner_instance, db_name(database_id), mirroring_state_desc, mirroring_safety_level_desc, cast(cast(context_info() as binary(8)) as datetime), datediff(s,cast(cast(context_info() as binary(8)) as datetime),getdate()) from sys.database_mirroring where db_name(database_id) like 'Adv%'; I declared @time as a binary(128) since CONTEXT_INFO is defined that way. I couldn't convert GETDATE() to binary(128) as it would pad the first 120 bytes as 0x00. To keep the CAST functions simple and avoid using SUBSTRING, I decided to CAST GETDATE() as binary(8) and let SQL Server do the implicit conversion. It's not the safest way perhaps, but it works on my machine. :) As I mentioned earlier, you can query system views for sessions and get their CONTEXT_INFO. With a little boilerplate code this can be used to monitor long-running procedures, in case you need to kill a process, or are just curious how long certain parts take. In this example, I added code to Adam's Big Adventure script to set CONTEXT_INFO messages at strategic places I want to monitor. (His code is in UPPERCASE as it was in the original, mine is all lowercase): declare @msg binary(128) set @msg=cast('Altering bigProduct.ProductID' as binary(128)) set context_info @msg go ALTER TABLE bigProduct ALTER COLUMN ProductID INT NOT NULL GO set context_info 0x0 go declare @msg1 binary(128) set @msg1=cast('Adding pk_bigProduct Constraint' as binary(128)) set context_info @msg1 go ALTER TABLE bigProduct ADD CONSTRAINT pk_bigProduct PRIMARY KEY (ProductID) GO set context_info 0x0 go declare @msg2 binary(128) set @msg2=cast('Altering bigTransactionHistory.TransactionID' as binary(128)) set context_info @msg2 go ALTER TABLE bigTransactionHistory ALTER COLUMN TransactionID INT NOT NULL GO set context_info 0x0 go declare @msg3 binary(128) set @msg3=cast('Adding pk_bigTransactionHistory Constraint' as binary(128)) set context_info @msg3 go ALTER TABLE bigTransactionHistory ADD CONSTRAINT pk_bigTransactionHistory PRIMARY KEY NONCLUSTERED(TransactionID) GO set context_info 0x0 go declare @msg4 binary(128) set @msg4=cast('Creating IX_ProductId_TransactionDate Index' as binary(128)) set context_info @msg4 go CREATE NONCLUSTERED INDEX IX_ProductId_TransactionDate ON bigTransactionHistory(ProductId,TransactionDate) INCLUDE(Quantity,ActualCost) GO set context_info 0x0 This doesn't include the entire script, only those portions that altered a table or created an index. One annoyance is that SET CONTEXT_INFO requires a literal or variable, you can't use an expression. And since GO starts a new batch I need to declare a variable in each one. And of course I have to use CAST because it won't implicitly convert varchar to binary. And even though context_info is a nullable column, you can't SET CONTEXT_INFO NULL, so I have to use SET CONTEXT_INFO 0x0 to clear the message after the statement completes. And if you're thinking of turning this into a UDF, you can't, although a stored procedure would work. So what does all this aggravation get you? As the code runs, if I want to see which stage the session is at, I can run the following (assuming SPID 51 is the one I want): select CAST(context_info as varchar(128)) from sys.dm_exec_sessions where session_id=51 Since SQL Server 2005 introduced the new system and dynamic management views (DMVs) there's not as much need for tagging a session with these kinds of messages. You can get the session start time and currently executing statement from them, and neatly presented if you use Adam's sp_whoisactive utility (and you absolutely should be using it). Of course you can always use xp_cmdshell, a CLR function, or some other tricks to log information outside of a SQL transaction. All the same, I've used this trick to monitor long-running reports at a previous job, and I still think CONTEXT_INFO is a great feature, especially if you're still using SQL Server 2000 or want to supplement your instrumentation. If you'd like an exercise, consider adding the system time to the messages in the last example, and an automated job to query and parse it from the system tables. That would let you track how long each statement ran without having to run Profiler. #TSQL2sDay

Read the article
Modern/Metro Internet Explorer: What were they thinking???

- by Rick Strahl

As I installed Windows 8.1 last week I decided that I really should take a closer look at Internet Explorer in the Modern/Metro environment again. Right away I ran into two issues that are real head scratchers to me.Modern Split Windows don't resize Viewport but Zoom OutThis one falls in the "WTF, really?" department: It looks like Modern Internet Explorer's Modern doesn't resize the browser window as every other browser (including IE 11 on the desktop) does, but rather tries to adjust the zoom to the width of the browser. This means that if you use the Modern IE browser and you split the display between IE and another application, IE will be zoomed out, with text becoming much, much smaller, rather than resizing the browser viewport and adjusting the pixel width as you would when a browser window is typically resized.Here's what I'm talking about in a couple of pictures. First here's the full screen Internet Explorer version (this shot is resized down since it's full screen at 1080p, click to see the full image):This brings up the first issue which is: On the desktop who wants to browse a site full screen? Most sites aren't fully optimized for 1080p widescreen experience and frankly most content that wide just looks weird. Even in typical 10" resolutions of 1280 width it's weird to look at things this way. At least this issue can be worked around with @media queries and either constraining the view, or adding additional content to make use of the extra space. Still running a desktop browser full screen is not optimal on a desktop machine - ever.Regardless, this view, while oversized, is what I expect: Everything is rendered in the right ratios, with font-size and the responsive design styling properly respected.But now look what happens when you split the desktop windows and show half desktop and have modern IE (this screen shot is not resized but cropped - this is actual size content as you can see in the cropped Twitter window on the right half of the screen):What's happening here is that IE is zooming out of the content to make it fit into the smaller width, shrinking the content rather than resizing the viewport's pixel width. In effect it looks like the pixel width stays at 1080px and the viewport expands out height-wise in response resulting in some crazy long portrait view.There goes responsive design - out the window literally. If you've built your site using @media queries and fixed viewport sizes, Internet Explorer completely screws you in this split view. On my 1080p monitor, the site shown at a little under half width becomes completely unreadable as the fonts are too small and break up. As you go into split view and you resize the window handle the content of the browser gets smaller and smaller (and effectively longer and longer on the bottom) effectively throwing off any responsive layout to the point of un-readability even on a big display, let alone a small tablet screen.What could POSSIBLY be the benefit of this screwed up behavior? I checked around a bit trying different pages in this shrunk down view. Other than the Microsoft home page, every page I went to was nearly unreadable at a quarter width. The only page I found that worked 'normally' was the Microsoft home page which undoubtedly is optimized just for Internet Explorer specifically.Bottom Address Bar opaquely overlays ContentAnother problematic feature for me is the browser address bar on the bottom. Modern IE shows the status bar opaquely on the bottom, overlaying the content area of the Web Page - until you click on the page. Until you do though, the address bar overlays the bottom content solidly. And not just a little bit but by good sizable chunk.In the application from the screen shot above I have an application toolbar on the bottom and the IE Address bar completely hides that bottom toolbar when the page is first loaded, until the user clicks into the content at which point the address bar shrinks down to a fat border style bar with a … on it. Toolbars on the bottom are pretty common these days, especially for mobile optimized applications, so I'd say this is a common use case. But even if you don't have toolbars on the bottom maybe there's other fixed content on the bottom of the page that is vital to display. While other browsers often also show address bars and then later hide them, these other browsers tend to resize the viewport when the address bar status changes, so the content can respond to the size change. Not so with Modern IE. The address bar overlays content and stays visible until content is clicked. No resize notification or viewport height change is sent to the browser.So basically Internet Explorer is telling me: "Our toolbar is more important than your content!" - AND gives me no chance to re-act to that behavior. The result on this page/application is that the user sees no actionable operations until he or she clicks into the content area, which is terrible from a UI perspective as the user has no idea what options are available on initial load.It's doubly confounding in that IE is running in full screen mode and has an the entire height of the screen at its disposal - there's plenty of real estate available to not require this sort of hiding of content in the first place. Heck, even Windows Phone with its more constrained size doesn't hide content - in fact the address bar on Windows Phone 8 is always visible.What were they thinking?Every time I use anything in the Modern Metro interface in Windows 8/8.1 I get angry. I can pretty much ignore Metro/Modern for my everyday usage, but unfortunately with Internet Explorer in the modern shell I have to live with, because there will be users using it to access my sites. I think it's inexcusable by Microsoft to build such a crappy shell around the browser that impacts the actual usability of Web content. In both of the cases above I can only scratch my head at what could have possibly motivated anybody designing the UI for the browser to make these screwed up choices, that manipulate the content in a totally unmaintainable way.© Rick Strahl, West Wind Technologies, 2005-2013Posted in Windows HTML5 Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

Read the article
ASP.NET MVC 3 Hosting :: MVC 2 Strongly Typed HTML Helper and Enhanced Validation Sample

- by mbridge

In lue of the off the official release of ASP.NET MVC 2 RTM, I decided I would put together a quick sample of the enhanced HTML.Helpers and validation controls. I am going to use my sample event site where I will have a form so a user can search for information about a certain events. So when the Search page loads the Search action is fired return my strongly typed model. to the view. 1: [HttpGet] 2: public ViewResult Search(): public ViewResult Search() 3: { 4: IList<EventsModel> result = _eventsService.GetEventList(); 5: var viewModel = new EventSearchModel 6: { 7: EventList = new SelectList(result, "EventCode","EventName","Select Event") 8: }; 9: return View(viewModel); 10: } Nothing special here, although I did want to show how to load up a strongly typed drop down list because that hung me up for a little bit. So to that, I am going to pass back a SelectList to the view and my HTML helper should no how to load this. So lets take a look at the mark up for the view. 1: <%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" 2: Inherits="System.Web.Mvc.ViewPage<EventsSample.Models.EventSearchModel>" %> 3: 4: <asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server"> 5: Search 6: </asp:Content> 7: 8: <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> 9: 10: <h2>Search for Events</h2> 11: 12: <% using (Html.BeginForm("Search","Events")) {%> 13: <%= Html.ValidationSummary(true) %> 14: 15: <fieldset> 16: <legend>Fields</legend> 17: 18: <div class="editor-label"> 19: <%= Html.LabelFor(model => model.EventNumber) %> 20: </div> 21: <div class="editor-field"> 22: <%= Html.TextBoxFor(model => model.EventNumber) %> 23: <%= Html.ValidationMessageFor(model => model.EventNumber) %> 24: </div> 25: 26: <div class="editor-label"> 27: <%= Html.LabelFor(model => model.GuestLastName) %> 28: </div> 29: <div class="editor-field"> 30: <%= Html.TextBoxFor(model => model.GuestLastName) %> 31: <%= Html.ValidationMessageFor(model => model.GuestLastName) %> 32: </div> 33: 34: <div class="editor-label"> 35: <%= Html.LabelFor(model => model.EventName) %> 36: </div> 37: <div class="editor-field"> 38: <%= Html.DropDownListFor(model => model.EventName, Model.EventList,"Select Event") %> 39: <%= Html.ValidationMessageFor(model => model.EventName) %> 40: </div> 41: 42: <p> 43: <input type="submit" value="Save" /> 44: </p> 45: </fieldset> 46: 47: <% } %> 48: 49: <div> 50: <%= Html.ActionLink("Back to List", "Index") %> 51: </div> 52: 53: </asp:Content> A nice feature is the scaffolding that MVC has to generate code. I simply right clicked inside my Search() action, inside the EventsController and selected “Add View” and then I selected my strongly typed object that I wanted to pass to the view and also selected that I wanted the content type be “Edit”. With that the aspx page was completely generated, although I did have to go back in and change the textbox for the Event Names to a drop down list of the names to select from. The new feature with MVC 2 are the strongly typed HTML helpers. So now, my textboxes, drop down list, and validation helpers are all strongly typed to my model. This features gives you the benefits of intellisense and also makes it easier to debug. “The Gu” has a great post about the feature in case you want more details. The DropDownListFor function to generate the drop down list was a little tricky for me. You first need to use a Lanbda expression to pass in the property you want the selected value assigned to in your model, and then you need to pass in the list directly from the model. Validations To validate the form, you can use the strongly type validation HTML helpers which will inspect your model and return errors if the validation fails. The definitions of these rules are set directly on the Model itself so lets take a look. 1: using System.ComponentModel.DataAnnotations; 2: using System.Web.Mvc; 3: 4: namespace EventsSample.Models 5: { 6: public class EventSearchModel 7: { 8: [Required(ErrorMessage = "Please enter the event number.")] 9: [RegularExpression(@"\w{6}", 10: ErrorMessage = "The Event Number must be 6 letters and/or numbers.")] 11: public string EventNumber { get; set; } 12: 13: [Required(ErrorMessage = "Please enter the guest's last name.")] 14: [RegularExpression(@"^[A-Za-zÀ-ÖØ-öø-ÿ1-9 '\-\.]{1,22}$", 15: ErrorMessage = "The gueest's last name must 1 to 20 characters.")] 16: public string GuestLastName { get; set; } 17: 18: public string EventName { get; set; } 19: public SelectList EventList { get; set; } 20: } 21: } Pretty cool! Okay, the only thing left to do is perform the validation in the POST action. 1: [HttpPost] 2: public ViewResult Search(EventSearchModel eventSearchModel) 3: { 4: if (ModelState.IsValid) return View("SearchResults"); 5: else 6: { 7: IList<EventsModel> result = _eventsService.GetEventList(); 8: eventSearchModel.EventList = new SelectList(result, "EVentCode","EventName"); 9: 10: return View(eventSearchModel); 11: } 12: } 13: } If the form entries are valid, here I am simply displaying the SearchResult, but in a real world sample I would also go out get the results first. You get the idea though. In my case, when the form is not valid, I also had to reload my SelectList with the event names before I loaded the page again. Remember this is MVC, no _VieState here :) So that’s it. Now my form is validating the data and when it fails it looks like this.

Read the article
T-SQL Tuesday #31 - Logging Tricks with CONTEXT_INFO

- by Most Valuable Yak (Rob Volk)

This month's T-SQL Tuesday is being hosted by Aaron Nelson [b | t], fellow Atlantan (the city in Georgia, not the famous sunken city, or the resort in the Bahamas) and covers the topic of logging (the recording of information, not the harvesting of trees) and maintains the fine T-SQL Tuesday tradition begun by Adam Machanic [b | t] (the SQL Server guru, not the guy who fixes cars, check the spelling again, there will be a quiz later). This is a trick I learned from Fernando Guerrero [b | t] waaaaaay back during the PASS Summit 2004 in sunny, hurricane-infested Orlando, during his session on Secret SQL Server (not sure if that's the correct title, and I haven't used parentheses in this paragraph yet). CONTEXT_INFO is a neat little feature that's existed since SQL Server 2000 and perhaps even earlier. It lets you assign data to the current session/connection, and maintains that data until you disconnect or change it. In addition to the CONTEXT_INFO() function, you can also query the context_info column in sys.dm_exec_sessions, or even sysprocesses if you're still running SQL Server 2000, if you need to see it for another session. While you're limited to 128 bytes, one big advantage that CONTEXT_INFO has is that it's independent of any transactions. If you've ever logged to a table in a transaction and then lost messages when it rolled back, you can understand how aggravating it can be. CONTEXT_INFO also survives across multiple SQL batches (GO separators) in the same connection, so for those of you who were going to suggest "just log to a table variable, they don't get rolled back": HA-HA, I GOT YOU! Since GO starts a new batch all variable declarations are lost. Here's a simple example I recently used at work. I had to test database mirroring configurations for disaster recovery scenarios and measure the network throughput. I also needed to log how long it took for the script to run and include the mirror settings for the database in question. I decided to use AdventureWorks as my database model, and Adam Machanic's Big Adventure script to provide a fairly large workload that's repeatable and easily scalable. My test would consist of several copies of AdventureWorks running the Big Adventure script while I mirrored the databases (or not). Since Adam's script contains several batches, I decided CONTEXT_INFO would have to be used. As it turns out, I only needed to grab the start time at the beginning, I could get the rest of the data at the end of the process. The code is pretty small: declare @time binary(128)=cast(getdate() as binary(8)) set context_info @time ... rest of Big Adventure code ... go use master; insert mirror_test(server,role,partner,db,state,safety,start,duration) select @@servername, mirroring_role_desc, mirroring_partner_instance, db_name(database_id), mirroring_state_desc, mirroring_safety_level_desc, cast(cast(context_info() as binary(8)) as datetime), datediff(s,cast(cast(context_info() as binary(8)) as datetime),getdate()) from sys.database_mirroring where db_name(database_id) like 'Adv%'; I declared @time as a binary(128) since CONTEXT_INFO is defined that way. I couldn't convert GETDATE() to binary(128) as it would pad the first 120 bytes as 0x00. To keep the CAST functions simple and avoid using SUBSTRING, I decided to CAST GETDATE() as binary(8) and let SQL Server do the implicit conversion. It's not the safest way perhaps, but it works on my machine. :) As I mentioned earlier, you can query system views for sessions and get their CONTEXT_INFO. With a little boilerplate code this can be used to monitor long-running procedures, in case you need to kill a process, or are just curious how long certain parts take. In this example, I added code to Adam's Big Adventure script to set CONTEXT_INFO messages at strategic places I want to monitor. (His code is in UPPERCASE as it was in the original, mine is all lowercase): declare @msg binary(128) set @msg=cast('Altering bigProduct.ProductID' as binary(128)) set context_info @msg go ALTER TABLE bigProduct ALTER COLUMN ProductID INT NOT NULL GO set context_info 0x0 go declare @msg1 binary(128) set @msg1=cast('Adding pk_bigProduct Constraint' as binary(128)) set context_info @msg1 go ALTER TABLE bigProduct ADD CONSTRAINT pk_bigProduct PRIMARY KEY (ProductID) GO set context_info 0x0 go declare @msg2 binary(128) set @msg2=cast('Altering bigTransactionHistory.TransactionID' as binary(128)) set context_info @msg2 go ALTER TABLE bigTransactionHistory ALTER COLUMN TransactionID INT NOT NULL GO set context_info 0x0 go declare @msg3 binary(128) set @msg3=cast('Adding pk_bigTransactionHistory Constraint' as binary(128)) set context_info @msg3 go ALTER TABLE bigTransactionHistory ADD CONSTRAINT pk_bigTransactionHistory PRIMARY KEY NONCLUSTERED(TransactionID) GO set context_info 0x0 go declare @msg4 binary(128) set @msg4=cast('Creating IX_ProductId_TransactionDate Index' as binary(128)) set context_info @msg4 go CREATE NONCLUSTERED INDEX IX_ProductId_TransactionDate ON bigTransactionHistory(ProductId,TransactionDate) INCLUDE(Quantity,ActualCost) GO set context_info 0x0 This doesn't include the entire script, only those portions that altered a table or created an index. One annoyance is that SET CONTEXT_INFO requires a literal or variable, you can't use an expression. And since GO starts a new batch I need to declare a variable in each one. And of course I have to use CAST because it won't implicitly convert varchar to binary. And even though context_info is a nullable column, you can't SET CONTEXT_INFO NULL, so I have to use SET CONTEXT_INFO 0x0 to clear the message after the statement completes. And if you're thinking of turning this into a UDF, you can't, although a stored procedure would work. So what does all this aggravation get you? As the code runs, if I want to see which stage the session is at, I can run the following (assuming SPID 51 is the one I want): select CAST(context_info as varchar(128)) from sys.dm_exec_sessions where session_id=51 Since SQL Server 2005 introduced the new system and dynamic management views (DMVs) there's not as much need for tagging a session with these kinds of messages. You can get the session start time and currently executing statement from them, and neatly presented if you use Adam's sp_whoisactive utility (and you absolutely should be using it). Of course you can always use xp_cmdshell, a CLR function, or some other tricks to log information outside of a SQL transaction. All the same, I've used this trick to monitor long-running reports at a previous job, and I still think CONTEXT_INFO is a great feature, especially if you're still using SQL Server 2000 or want to supplement your instrumentation. If you'd like an exercise, consider adding the system time to the messages in the last example, and an automated job to query and parse it from the system tables. That would let you track how long each statement ran without having to run Profiler. #TSQL2sDay

Read the article
C# Performance Pitfall – Interop Scenarios Change the Rules

- by Reed

C# and .NET, overall, really do have fantastic performance in my opinion. That being said, the performance characteristics dramatically differ from native programming, and take some relearning if you’re used to doing performance optimization in most other languages, especially C, C++, and similar. However, there are times when revisiting tricks learned in native code play a critical role in performance optimization in C#. I recently ran across a nasty scenario that illustrated to me how dangerous following any fixed rules for optimization can be… The rules in C# when optimizing code are very different than C or C++. Often, they’re exactly backwards. For example, in C and C++, lifting a variable out of loops in order to avoid memory allocations often can have huge advantages. If some function within a call graph is allocating memory dynamically, and that gets called in a loop, it can dramatically slow down a routine. This can be a tricky bottleneck to track down, even with a profiler. Looking at the memory allocation graph is usually the key for spotting this routine, as it’s often “hidden” deep in call graph. For example, while optimizing some of my scientific routines, I ran into a situation where I had a loop similar to: for (i=0; i<numberToProcess; ++i) { // Do some work ProcessElement(element[i]); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This loop was at a fairly high level in the call graph, and often could take many hours to complete, depending on the input data. As such, any performance optimization we could achieve would be greatly appreciated by our users. After a fair bit of profiling, I noticed that a couple of function calls down the call graph (inside of ProcessElement), there was some code that effectively was doing: // Allocate some data required DataStructure* data = new DataStructure(num); // Call into a subroutine that passed around and manipulated this data highly CallSubroutine(data); // Read and use some values from here double values = data->Foo; // Cleanup delete data; // ... return bar; Normally, if “DataStructure” was a simple data type, I could just allocate it on the stack. However, it’s constructor, internally, allocated it’s own memory using new, so this wouldn’t eliminate the problem. In this case, however, I could change the call signatures to allow the pointer to the data structure to be passed into ProcessElement and through the call graph, allowing the inner routine to reuse the same “data” memory instead of allocating. At the highest level, my code effectively changed to something like: DataStructure* data = new DataStructure(numberToProcess); for (i=0; i<numberToProcess; ++i) { // Do some work ProcessElement(element[i], data); } delete data; Granted, this dramatically reduced the maintainability of the code, so it wasn’t something I wanted to do unless there was a significant benefit. In this case, after profiling the new version, I found that it increased the overall performance dramatically – my main test case went from 35 minutes runtime down to 21 minutes. This was such a significant improvement, I felt it was worth the reduction in maintainability. In C and C++, it’s generally a good idea (for performance) to: Reduce the number of memory allocations as much as possible, Use fewer, larger memory allocations instead of many smaller ones, and Allocate as high up the call stack as possible, and reuse memory I’ve seen many people try to make similar optimizations in C# code. For good or bad, this is typically not a good idea. The garbage collector in .NET completely changes the rules here. In C#, reallocating memory in a loop is not always a bad idea. In this scenario, for example, I may have been much better off leaving the original code alone. The reason for this is the garbage collector. The GC in .NET is incredibly effective, and leaving the allocation deep inside the call stack has some huge advantages. First and foremost, it tends to make the code more maintainable – passing around object references tends to couple the methods together more than necessary, and overall increase the complexity of the code. This is something that should be avoided unless there is a significant reason. Second, (unlike C and C++) memory allocation of a single object in C# is normally cheap and fast. Finally, and most critically, there is a large advantage to having short lived objects. If you lift a variable out of the loop and reuse the memory, its much more likely that object will get promoted to Gen1 (or worse, Gen2). This can cause expensive compaction operations to be required, and also lead to (at least temporary) memory fragmentation as well as more costly collections later. As such, I’ve found that it’s often (though not always) faster to leave memory allocations where you’d naturally place them – deep inside of the call graph, inside of the loops. This causes the objects to stay very short lived, which in turn increases the efficiency of the garbage collector, and can dramatically improve the overall performance of the routine as a whole. In C#, I tend to: Keep variable declarations in the tightest scope possible Declare and allocate objects at usage While this tends to cause some of the same goals (reducing unnecessary allocations, etc), the goal here is a bit different – it’s about keeping the objects rooted for as little time as possible in order to (attempt) to keep them completely in Gen0, or worst case, Gen1. It also has the huge advantage of keeping the code very maintainable – objects are used and “released” as soon as possible, which keeps the code very clean. It does, however, often have the side effect of causing more allocations to occur, but keeping the objects rooted for a much shorter time. Now – nowhere here am I suggesting that these rules are hard, fast rules that are always true. That being said, my time spent optimizing over the years encourages me to naturally write code that follows the above guidelines, then profile and adjust as necessary. In my current project, however, I ran across one of those nasty little pitfalls that’s something to keep in mind – interop changes the rules. In this case, I was dealing with an API that, internally, used some COM objects. In this case, these COM objects were leading to native allocations (most likely C++) occurring in a loop deep in my call graph. Even though I was writing nice, clean managed code, the normal managed code rules for performance no longer apply. After profiling to find the bottleneck in my code, I realized that my inner loop, a innocuous looking block of C# code, was effectively causing a set of native memory allocations in every iteration. This required going back to a “native programming” mindset for optimization. Lifting these variables and reusing them took a 1:10 routine down to 0:20 – again, a very worthwhile improvement. Overall, the lessons here are: Always profile if you suspect a performance problem – don’t assume any rule is correct, or any code is efficient just because it looks like it should be Remember to check memory allocations when profiling, not just CPU cycles Interop scenarios often cause managed code to act very differently than “normal” managed code. Native code can be hidden very cleverly inside of managed wrappers

Read the article
SQL University: What and why of database testing

- by Mladen Prajdic

This is a post for a great idea called SQL University started by Jorge Segarra also famously known as SqlChicken on Twitter. It’s a collection of blog posts on different database related topics contributed by several smart people all over the world. So this week is mine and we’ll be talking about database testing and refactoring. In 3 posts we’ll cover: SQLU part 1 - What and why of database testing SQLU part 2 - What and why of database refactoring SQLU part 2 – Tools of the trade With that out of the way let us sharpen our pencils and get going. Why test a database The sad state of the industry today is that there is very little emphasis on testing in general. Test driven development is still a small niche of the programming world while refactoring is even smaller. The cause of this is the inability of developers to convince themselves and their managers that writing tests is beneficial. At the moment they are mostly viewed as waste of time. This is because the average person (let’s not fool ourselves, we’re all average) is unable to think about lower future costs in relation to little more current work. It’s orders of magnitude easier to know about the current costs in relation to current amount of work. That’s why programmers convince themselves testing is a waste of time. However we have to ask ourselves what tests are really about? Maybe finding bugs? No, not really. If we introduce bugs, we’re likely to write test around those bugs too. But yes we can find some bugs with tests. The main point of tests is to have reproducible repeatability in our systems. By having a code base largely covered by tests we can know with better certainty what a small code change can break in other parts of the system. By having repeatability we can make code changes with confidence, since we know we’ll see what breaks in other tests. And here comes the inability to estimate future costs. By spending just a few more hours writing those tests we’d know instantly what broke where. Imagine we fix a reported bug. We check-in the code, deploy it and the users are happy. Until we get a call 2 weeks later about a certain monthly process has stopped working. What we don’t know is that this process was developed by a long gone coworker and for some reason it relied on that same bug we’ve happily fixed. There’s no way we could’ve known that. We say OK and go in and fix the monthly process. But what we have no clue about is that there’s this ETL job that relied on data from that monthly process. Now that we’ve fixed the process it’s giving unexpected (yet correct since we fixed it) data to the ETL job. So we have to fix that too. But there’s this part of the app we coded that relies on data from that exact ETL job. And just like that we enter the “Loop of maintenance horror”. With the loop eventually comes blame. Here’s a nice tip for all developers and DBAs out there: If you make a mistake man up and admit to it. All of the above is valid for any kind of software development. Keeping this in mind the database is nothing other than just a part of the application. But a big part! One reason why testing a database is even more important than testing an application is that one database is usually accessed from multiple applications and processes. This makes it the central and vital part of the enterprise software infrastructure. Knowing all this can we really afford not to have tests? What to test in a database Now that we’ve decided we’ll dive into this testing thing we have to ask ourselves what needs to be tested? The short answer is: everything. The long answer is: read on! There are 2 main ways of doing tests: Black box and White box testing. Black box testing means we have no idea how the system internals are built and we only have access to it’s inputs and outputs. With it we test that the internal changes to the system haven’t caused the input/output behavior of the system to change. The most important thing to test here are the edge conditions. It’s where most programs break. Having good edge condition tests we can be more confident that the systems changes won’t break. White box testing has the full knowledge of the system internals. With it we test the internal system changes, different states of the application, etc… White and Black box tests should be complementary to each other as they are very much interconnected. Testing database routines includes testing stored procedures, views, user defined functions and anything you use to access the data with. Database routines are your input/output interface to the database system. They count as black box testing. We test then for 2 things: Data and schema. When testing schema we only care about the columns and the data types they’re returning. After all the schema is the contract to the out side systems. If it changes we usually have to change the applications accessing it. One helpful T-SQL command when doing schema tests is SET FMTONLY ON. It tells the SQL Server to return only empty results sets. This speeds up tests because it doesn’t return any data to the client. After we’ve validated the schema we have to test the returned data. There no other way to do this but to have expected data known before the tests executes and comparing that data to the database routine output. Testing Authentication and Authorization helps us validate who has access to the SQL Server box (Authentication) and who has access to certain database objects (Authorization). For desktop applications and windows authentication this works well. But the biggest problem here are web apps. They usually connect to the database as a single user. Please ensure that that user is not SA or an account with admin privileges. That is just bad. Load testing ensures us that our database can handle peak loads. One often overlooked tool for load testing is Microsoft’s OSTRESS tool. It’s part of RML utilities (x86, x64) for SQL Server and can help determine if our database server can handle loads like 100 simultaneous users each doing 10 requests per second. SQL Profiler can also help us here by looking at why certain queries are slow and what to do to fix them. One particular problem to think about is how to begin testing existing databases. First thing we have to do is to get to know those databases. We can’t test something when we don’t know how it works. To do this we have to talk to the users of the applications accessing the database, run SQL Profiler to see what queries are being run, use existing documentation to decipher all the object relationships, etc… The way to approach this is to choose one part of the database (say a logical grouping of tables that go together) and filter our traces accordingly. Once we’ve done that we move on to the next grouping and so on until we’ve covered the whole database. Then we move on to the next one. Database Testing is a topic that we can spent many hours discussing but let this be a nice intro to the world of database testing. See you in the next post.

Read the article
Rebuilding CoasterBuzz, Part III: The architecture using the "Web stack of love"

- by Jeff

This is the third post in a series about rebuilding one of my Web sites, which has been around for 12 years. I hope to relaunch in the next month or two. More: Part I: Evolution, and death to WCF Part II: Hot data objects I finally hit a point in the re-do of CoasterBuzz where I feel like the major pieces are in place... rewritten, ported and what not, so that I can focus now on front-end design and more interesting creative problems. I've been asked on more than one occasion (OK, just twice) what's going on under the covers, so I figure this might be a good time to explain the overall architecture. As it turns out, I'm using a whole lof of the "Web stack of love," as Scott Hanselman likes to refer to it. Oh that Hanselman. First off, at the center of it all, is BizTalk. Just kidding. That's "enterprise architecture" humor, where every discussion starts with how they'll use BizTalk. Here are the bigger moving parts: It's fairly straight forward. A common library lives in a number of Web apps, all of which are (or will be) powered by ASP.NET MVC 4. They all talk to the same database. There is the main Web site, which also has the endpoint for the Silverlight-based Feed app. The cstr.bz site handles redirects, which are generated when news items are published and sent to Twitter. Facebook publishing is handled via the RSS Graffiti Facebook app. The API site handles requests from the Windows Phone app. The main site depends very heavily on POP Forums, the open source, MVC-based forum I maintain. It serves a number of functions, primarily handling users. These user objects serve in non-forum roles to handle things like news and database contributions, maintaining track records (coaster nerd for "list of rides I've been on") and, perhaps most importantly, paid club memberships. Before I get into more specifics, note that the "glue" for everything is Ninject, the dependency injection framework. I actually prefer StructureMap these days, but I started with Ninject in POP Forums a long time ago. POP Forums has a static class, PopForumsActivation, that new's up an instance of the container, and you can call it from where ever. The downside is that the forums require Ninject in your MVC app as the default dependency resolver. At some point, I'll decouple it, but for now it's not in the way. In the general sense, the entire set of apps follow a repository-service-controller-view pattern. Repos just do data access, service classes do business logic, controllers compose and route, views view. The forum also provides Scoring Game functionality. The Scoring Game is a reasonably abstract framework to award users points based on certain actions, and then award achievements when a certain number of point events happen. For example, the forum already awards a point when someone plus-one's a post you made. You can set up an achievement that says, "Give the user an award when they've had 100 posts plus'd." It also does zero-point entries into the ledger, so if you make a post, you could award an achievement based on 100 posts made. Wiring in the scoring game to CoasterBuzz functionality is just a matter of going to the Ninject container and getting an instance of the event publisher, and passing it events. Forum adapters were introduced into POP Forums a few versions ago, and they can intercept the model generated for forum topic lists and threads and designate an alternate view. These are used to make the "Day in Pictures" forum, where users can upload photos as frame-by-frame photo threads. Another adapter adds an association UI, so users can associate specific amusement parks with their trip report posts. The Silverlight-based Feed app talks to a simple JSON endpoint in the main app. This uses an underlying library I wrote ages ago, simply called Feeds, that aggregates event information. You inherit from a base class that creates instances of a publisher interface, and then use that class to send it an event type and any number of data fields. Feeds has two publishers: One is to the database, and that's used for the endpoint that talks to the Silverlight app. The second publisher publishes to Twitter, if the event is of the type "news." The wiring is a little strange, because for the new posts and topics events, I'm actually pulling out the forum repository classes from the Ninject container and replacing them with overridden methods to publish. I should probably be doing this at the service class level, but whatever. It's my mess. cstr.bz doesn't do anything interesting. It looks up the path, and if it has a match, does a 301 redirect to the long URL. The API site just serves up JSON for the Windows Phone app. The Windows Phone app is Silverlight, of course, and there isn't much to it. It does use the control toolkit, but beyond that, it relies on a simple class that creates a Webclient and calls the server for JSON to deserialize. The same class is now used by the Feed app, which used to use WCF. Simple is better. Data access in POP Forums is all straight SQL, because a lot of it was ported from the ASP.NET version. Most CoasterBuzz data access is handled by the Entity Framework, using the code-first model. The context class in this case does a lot of work to make sure that the table and key mapping works, since much of it breaks from the normal conventions of EF. One of the more powerful things you can do with EF, once you understand the little gotchas, is split tables by row into different entities. For example, a roller coaster photo has everything in the same row, including the metadata, the thumbnail bytes and the image itself. Obviously, if you want to get a list of photos to iterate over in a view, you don't want to get the image data. The use of navigation properties makes it easier to get just what you want. The front end includes Razor views in MVC, and jQuery is used for client-side goodness. I'm also using jQuery UI in a few places, for tabs, a dialog box and autocomplete. I'm also, tentatively, using jQuery Mobile. I've already ported most forum views to Mobile, but they need some work as v1.1 isn't finished yet. I'm not sure if I'll ship CoasterBuzz with mobile views or not yet. It's on the radar, but not something in my delivery criteria. That covers all of the big frameworks in play. Next time I hope to talk more about the front-end experience, which to me is where most of the fun is these days. Hoping to launch in the next month or two. Getting tired of looking at the old site!

Read the article
DBCC CHECKDB on VVLDB and latches (Or: My Pain is Your Gain)

- by Argenis

Does your CHECKDB hurt, Argenis? There is a classic blog series by Paul Randal [blog|twitter] called “CHECKDB From Every Angle” which is pretty much mandatory reading for anybody who’s even remotely considering going for the MCM certification, or its replacement (the Microsoft Certified Solutions Master: Data Platform – makes my fingers hurt just from typing it). Of particular interest is the post “Consistency Options for a VLDB” – on it, Paul provides solid, timeless advice (I use the word “timeless” because it was written in 2007, and it all applies today!) on how to perform checks on very large databases. Well, here I was trying to figure out how to make CHECKDB run faster on a restored copy of one of our databases, which happens to exceed 7TB in size. The whole thing was taking several days on multiple systems, regardless of the storage used – SAS, SATA or even SSD…and I actually didn’t pay much attention to how long it was taking, or even bothered to look at the reasons why - as long as it was finishing okay and found no consistency errors. Yes – I know. That was a huge mistake, as corruption found in a database several days after taking place could only allow for further spread of the corruption – and potentially large data loss. In the last two weeks I increased my attention towards this problem, as we noticed that CHECKDB was taking EVEN LONGER on brand new all-flash storage in the SAN! I couldn’t really explain it, and were almost ready to blame the storage vendor. The vendor told us that they could initially see the server driving decent I/O – around 450Mb/sec, and then it would settle at a very slow rate of 10Mb/sec or so. “Hum”, I thought – “CHECKDB is just not pushing the I/O subsystem hard enough”. Perfmon confirmed the vendor’s observations. Dreaded @BlobEater What was CHECKDB doing all the time while doing so little I/O? Eating Blobs. It turns out that CHECKDB was taking an extremely long time on one of our frankentables, which happens to be have 35 billion rows (yup, with a b) and sucks up several terabytes of space in the database. We do have a project ongoing to purge/split/partition this table, so it’s just a matter of time before we deal with it. But the reality today is that CHECKDB is coming to a screeching halt in performance when dealing with this particular table. Checking sys.dm_os_waiting_tasks and sys.dm_os_latch_stats showed that LATCH_EX (DBCC_OBJECT_METADATA) was by far the top wait type. I remembered hearing recently about that wait from another post that Paul Randal made, but that was related to computed-column indexes, and in fact, Paul himself reminded me of his article via twitter. But alas, our pathologic table had no non-clustered indexes on computed columns. I knew that latches are used by the database engine to do internal synchronization – but how could I help speed this up? After all, this is stuff that doesn’t have a lot of knobs to tweak. (There’s a fantastic level 500 talk by Bob Ward from Microsoft CSS [blog|twitter] called “Inside SQL Server Latches” given at PASS 2010 – and you can check it out here. DISCLAIMER: I assume no responsibility for any brain melting that might ensue from watching Bob’s talk!) Failed Hypotheses Earlier on this week I flew down to Palo Alto, CA, to visit our Headquarters – and after having a great time with my Monkey peers, I was relaxing on the plane back to Seattle watching a great talk by SQL Server MVP and fellow MCM Maciej Pilecki [twitter] called “Masterclass: A Day in the Life of a Database Transaction” where he discusses many different topics related to transaction management inside SQL Server. Very good stuff, and when I got home it was a little late – that slow DBCC CHECKDB that I had been dealing with was way in the back of my head. As I was looking at the problem at hand earlier on this week, I thought “How about I set the database to read-only?” I remembered one of the things Maciej had (jokingly) said in his talk: “if you don’t want locking and blocking, set the database to read-only” (or something to that effect, pardon my loose memory). I immediately killed the CHECKDB which had been running painfully for days, and set the database to read-only mode. Then I ran DBCC CHECKDB against it. It started going really fast (even a bit faster than before), and then throttled down again to around 10Mb/sec. All sorts of expletives went through my head at the time. Sure enough, the same latching scenario was present. Oh well. I even spent some time trying to figure out if NUMA was hurting performance. Folks on Twitter made suggestions in this regard (thanks, Lonny! [twitter]) …Eureka? This past Friday I was still scratching my head about the whole thing; I was ready to start profiling with XPERF to see if I could figure out which part of the engine was to blame and then get Microsoft to look at the evidence. After getting a bunch of good news I’ll blog about separately, I sat down for a figurative smack down with CHECKDB before the weekend. And then the light bulb went on. A sparse column. I thought that I couldn’t possibly be experiencing the same scenario that Paul blogged about back in March showing extreme latching with non-clustered indexes on computed columns. Did I even have a non-clustered index on my sparse column? As it turns out, I did. I had one filtered non-clustered index – with the sparse column as the index key (and only column). To prove that this was the problem, I went and setup a test. Yup, that'll do it The repro is very simple for this issue: I tested it on the latest public builds of SQL Server 2008 R2 SP2 (CU6) and SQL Server 2012 SP1 (CU4). First, create a test database and a test table, which only needs to contain a sparse column: CREATE DATABASE SparseColTest; GO USE SparseColTest; GO CREATE TABLE testTable (testCol smalldatetime SPARSE NULL); GO INSERT INTO testTable (testCol) VALUES (NULL); GO 1000000 That’s 1 million rows, and even though you’re inserting NULLs, that’s going to take a while. In my laptop, it took 3 minutes and 31 seconds. Next, we run DBCC CHECKDB against the database: DBCC CHECKDB('SparseColTest') WITH NO_INFOMSGS, ALL_ERRORMSGS; This runs extremely fast, as least on my test rig – 198 milliseconds. Now let’s create a filtered non-clustered index on the sparse column: CREATE NONCLUSTERED INDEX [badBadIndex] ON testTable (testCol) WHERE testCol IS NOT NULL; With the index in place now, let’s run DBCC CHECKDB one more time: DBCC CHECKDB('SparseColTest') WITH NO_INFOMSGS, ALL_ERRORMSGS; In my test system this statement completed in 11433 milliseconds. 11.43 full seconds. Quite the jump from 198 milliseconds. I went ahead and dropped the filtered non-clustered indexes on the restored copy of our production database, and ran CHECKDB against that. We went down from 7+ days to 19 hours and 20 minutes. Cue the “Argenis is not impressed” meme, please, Mr. LaRock. My pain is your gain, folks. Go check to see if you have any of such indexes – they’re likely causing your consistency checks to run very, very slow. Happy CHECKDBing, -Argenis ps: I plan to file a Connect item for this issue – I consider it a pretty serious bug in the engine. After all, filtered indexes were invented BECAUSE of the sparse column feature – and it makes a lot of sense to use them together. Watch this space and my twitter timeline for a link.

Read the article
DRY and SRP

- by Timothy Klenke

Originally posted on: http://geekswithblogs.net/TimothyK/archive/2014/06/11/dry-and-srp.aspxKent Beck’s XP Simplicity Rules (aka Four Rules of Simple Design) are a prioritized list of rules that when applied to your code generally yield a great design. As you’ll see from the above link the list has slightly evolved over time. I find today they are usually listed as: All Tests Pass Don’t Repeat Yourself (DRY) Express Intent Minimalistic These are prioritized. If your code doesn’t work (rule 1) then everything else is forfeit. Go back to rule one and get the code working before worrying about anything else. Over the years the community have debated whether the priority of rules 2 and 3 should be reversed. Some say a little duplication in the code is OK as long as it helps express intent. I’ve debated it myself. This recent post got me thinking about this again, hence this post. I don’t think it is fair to compare “Expressing Intent” against “DRY”. This is a comparison of apples to oranges. “Expressing Intent” is a principal of code quality. “Repeating Yourself” is a code smell. A code smell is merely an indicator that there might be something wrong with the code. It takes further investigation to determine if a violation of an underlying principal of code quality has actually occurred. For example “using nouns for method names”, “using verbs for property names”, or “using Booleans for parameters” are all code smells that indicate that code probably isn’t doing a good job at expressing intent. They are usually very good indicators. But what principle is the code smell of Duplication pointing to and how good of an indicator is it? Duplication in the code base is bad for a couple reasons. If you need to make a change and that needs to be made in a number of locations it is difficult to know if you have caught all of them. This can lead to bugs if/when one of those locations is overlooked. By refactoring the code to remove all duplication there will be left with only one place to change, thereby eliminating this problem. With most projects the code becomes the single source of truth for a project. If a production code base is inconsistent with a five year old requirements or design document the production code that people are currently living with is usually declared as the current reality (or truth). Requirement or design documents at this age in a project life cycle are usually of little value. Although comparing production code to external documentation is usually straight forward, duplication within the code base muddles this declaration of truth. When code is duplicated small discrepancies will creep in between the two copies over time. The question then becomes which copy is correct? As different factions debate how the software should work, trust in the software and the team behind it erodes. The code smell of Duplication points to a violation of the “Single Source of Truth” principle. Let me define that as: A stakeholder’s requirement for a software change should never cause more than one class to change. Violation of the Single Source of Truth principle will always result in duplication in the code. However, the inverse is not always true. Duplication in the code does not necessarily indicate that there is a violation of the Single Source of Truth principle. To illustrate this, let’s look at a retail system where the system will (1) send a transaction to a bank and (2) print a receipt for the customer. Although these are two separate features of the system, they are closely related. The reason for printing the receipt is usually to provide an audit trail back to the bank transaction. Both features use the same data: amount charged, account number, transaction date, customer name, retail store name, and etcetera. Because both features use much of the same data, there is likely to be a lot of duplication between them. This duplication can be removed by making both features use the same data access layer. Then start coming the divergent requirements. The receipt stakeholder wants a change so that the account number has the last few digits masked out to protect the customer’s privacy. That can be solve with a small IF statement whilst still eliminating all duplication in the system. Then the bank wants to take a picture of the customer as well as capture their signature and/or PIN number for enhanced security. Then the receipt owner wants to pull data from a completely different system to report the customer’s loyalty program point total. After a while you realize that the two stakeholders have somewhat similar, but ultimately different responsibilities. They have their own reasons for pulling the data access layer in different directions. Then it dawns on you, the Single Responsibility Principle: There should never be more than one reason for a class to change. In this example we have two stakeholders giving two separate reasons for the data access class to change. It is clear violation of the Single Responsibility Principle. That’s a problem because it can often lead the project owner pitting the two stakeholders against each other in a vein attempt to get them to work out a mutual single source of truth. But that doesn’t exist. There are two completely valid truths that the developers need to support. How is this to be supported and honour the Single Responsibility Principle? The solution is to duplicate the data access layer and let each stakeholder control their own copy. The Single Source of Truth and Single Responsibility Principles are very closely related. SST tells you when to remove duplication; SRP tells you when to introduce it. They may seem to be fighting each other, but really they are not. The key is to clearly identify the different responsibilities (or sources of truth) over a system. Sometimes there is a single person with that responsibility, other times there are many. This can be especially difficult if the same person has dual responsibilities. They might not even realize they are wearing multiple hats. In my opinion Single Source of Truth should be listed as the second rule of simple design with Express Intent at number three. Investigation of the DRY code smell should yield to the proper application SST, without violating SRP. When necessary leave duplication in the system and let the class names express the different people that are responsible for controlling them. Knowing all the people with responsibilities over a system is the higher priority because you’ll need to know this before you can express it. Although it may be a code smell when there is duplication in the code, it does not necessarily mean that the coder has chosen to be expressive over DRY or that the code is bad.

Read the article
Visiting the Fire Station in Coromandel

Hm, I just tried to remember how we actually came up with this cool idea... but it's already too blurred and it doesn't really matter after all. Anyway, if I remember correctly (IIRC), it happened during one of the Linux meetups at Mugg & Bean, Bagatelle where Ajay and I brought our children along and we had a brief conversation about how cool it would be to check out one of the fire stations here in Mauritius. We both thought that it would be a great experience and adventure for the little ones. An idea takes shape And there we go, down the usual routine these... having an idea, checking out the options and discussing who's doing what. Except this time, it was all up to Ajay, and he did a fantastic job. End of August, he told me that he got in touch with one of his friends which actually works as a fire fighter at the station in Coromandel and that there could be an option to come and visit them (soon). A couple of days later - Confirmed! Be there, and in time... What time? Anyway, doesn't really matter... Everything was settled and arranged. I asked the kids on Friday afternoon if they might be interested to see the fire engines and what a fire fighter is doing. Of course, they were all in! Getting up early on Sunday morning isn't really a regular exercise for all of us but everything went smooth and after a short breakfast it was time to leave. Where are we going? Are we there yet? Now, we are in Bambous. Why do you go this way? The kids were so much into it. Absolutely amazing to see their excitement. Are we there yet? Well, we went through the sugar cane fields towards Chebel and then down into the industrial zone at Coromandel. Honestly, I had a clue where the fire station is located but having Google Maps in reach that shouldn't be a problem in case that we might get lost. But my worries were washed away when our children guided us... "There! Over there are the fire engines! We have to turn left, dad." - No comment, the kids were right! As we were there a little bit too early, we parked the car and the kids started to explore the area and outskirts of the fire station. Some minutes later, as if we had placed an order a unit of two cars had to go out for an alarm and the kids could witness them leaving as closely as possible. Sirens on and wow!!! Ladder truck L32 - MAN truck with Rosenbauer built-up and equipment by Metz Taking the tour Ajay arrived shortly after that and guided us finally inside the station to meet with his pal. The three guys were absolutely well-prepared and showed us around in the hall, explaining that there two units out at the moment. But the ladder truck (with max. 32m expandable height) was still around we all got a great insight into the technique and equipment on the vehicle. It was amazing to see all three kids listening to Mambo as give some figures about the truck and how the fire fighters are actually it. The children and 'our' fire fighters of the day had great fun with the various fire engines Absolutely fantastic that the children were allowed to experience this - we had so much fun! Ajay's son brought two of his toy fire engines along, shared them with ours, and they all played very well together. As a parent it was really amazing to see them at such an ease. Enough theory Shortly afterwards the ladder truck was moved outside, got stabilised and ready to go for 'real-life' exercising. With the additional equipment of safety helmets, security belts and so on, we all got a first-hand impression about how it could be as a fire-fighter. Actually, I was totally amazed by the curiousity and excitement of my BWE. She was really into it and asked lots of interesting questions - in general but also technical. And while our fighters were busy with Ajay and family, I gave her some more details and explanations about the truck, the expandable ladder, the safety cage at the top and other equipment available. Safety first! No exceptions and always be prepared for the worst case... Also, the equipped has been checked prior to excuse - This is your life saver... Hooked up and ready to go... ...of course not too high. This is just a demonstration - and 32 meters above ground isn't for everyone. Well, after that it was me that had the asking looks on me, and I finally revealed to the local fire fighters that I was in the auxiliary fire brigade, more precisely in the hazard department, for more than 10 years. So not a professional fire fighter but at least a passionate and educated one as them. Inside the station Our fire fighters really took their time to explain their daily job to kids, provided them access to operation seat on the ladder truck and how the truck cabin is actually equipped with the different radios and so on. It was really a great time. Later on we had a brief tour through the building itself, and again all of our questions were answered. We had great fun and started to joke about bits and pieces. For me it was also very interesting to see the comparison between the fire station here in Mauritius and the ones I have been to back in Germany. Amazing to see them completely captivated in the play - the children had lots of fun! Also, that there are currently ten fire stations all over the island, plus two additional but private ones at the airport and at the harbour. The newest one is actually down in Black River on the west coast because the time from Quatre Bornes takes too long to have any chance of an effective alarm at all. IMHO, a very good decision as time is the most important factor in getting fire incidents under control. After all it was great experience for all of us, especially for the children to see and understand that their toy trucks are only copies of the real thing and that the job of a (professional) fire fighter is very important in our society. Don't forget that those guys run into the danger zone while you're trying to get away from it as much as possible. Another unit just came back from a grass fire - and shortly after they went out again. No time to rest, too much to do! Mauritian Fire Fighters now and (maybe) in the future... Thank you! It was an honour to be around! Thank you to Ajay for organising and arranging this Sunday morning event, and of course of Big Thank You to the three guys that took some time off to have us at the Fire Station in Coromandel and guide us through their daily job! And remember to call 115 in case of emergencies!

Read the article
Why you need to learn async in .NET

- by PSteele

I had an opportunity to teach a quick class yesterday about what’s new in .NET 4.0. One of the topics was the TPL (Task Parallel Library) and how it can make async programming easier. I also stressed that this is the direction Microsoft is going with for C# 5.0 and learning the TPL will greatly benefit their understanding of the new async stuff. We had a little time left over and I was able to show some code that uses the Async CTP to accomplish some stuff, but it wasn’t a simple demo that you could jump in to and understand so I thought I’d thrown one together and put it in a blog post. The entire solution file with all of the sample projects is located here. A Simple Example Let’s start with a super-simple example (WindowsApplication01 in the solution). I’ve got a form that displays a label and a button. When the user clicks the button, I want to start displaying the current time for 15 seconds and then stop. What I’d like to write is this: lblTime.ForeColor = Color.Red; for (var x = 0; x < 15; x++) { lblTime.Text = DateTime.Now.ToString("HH:mm:ss"); Thread.Sleep(1000); } lblTime.ForeColor = SystemColors.ControlText; (Note that I also changed the label’s color while counting – not quite an ILM-level effect, but it adds something to the demo!) As I’m sure most of my readers are aware, you can’t write WinForms code this way. WinForms apps, by default, only have one thread running and it’s main job is to process messages from the windows message pump (for a more thorough explanation, see my Visual Studio Magazine article on multithreading in WinForms). If you put a Thread.Sleep in the middle of that code, your UI will be locked up and unresponsive for those 15 seconds. Not a good UX and something that needs to be fixed. Sure, I could throw an “Application.DoEvents()” in there, but that’s hacky. The Windows Timer Then I think, “I can solve that. I’ll use the Windows Timer to handle the timing in the background and simply notify me when the time has changed”. Let’s see how I could accomplish this with a Windows timer (WindowsApplication02 in the solution): public partial class Form1 : Form { private readonly Timer clockTimer; private int counter; public Form1() { InitializeComponent(); clockTimer = new Timer {Interval = 1000}; clockTimer.Tick += UpdateLabel; } private void UpdateLabel(object sender, EventArgs e) { lblTime.Text = DateTime.Now.ToString("HH:mm:ss"); counter++; if (counter == 15) { clockTimer.Enabled = false; lblTime.ForeColor = SystemColors.ControlText; } } private void cmdStart_Click(object sender, EventArgs e) { lblTime.ForeColor = Color.Red; counter = 0; clockTimer.Start(); } } Holy cow – things got pretty complicated here. I use the timer to fire off a Tick event every second. Inside there, I can update the label. Granted, I can’t use a simple for/loop and have to maintain a global counter for the number of iterations. And my “end” code (when the loop is finished) is now buried inside the bottom of the Tick event (inside an “if” statement). I do, however, get a responsive application that doesn’t hang or stop repainting while the 15 seconds are ticking away. But doesn’t .NET have something that makes background processing easier? The BackgroundWorker Next I try .NET’s BackgroundWorker component – it’s specifically designed to do processing in a background thread (leaving the UI thread free to process the windows message pump) and allows updates to be performed on the main UI thread (WindowsApplication03 in the solution): public partial class Form1 : Form { private readonly BackgroundWorker worker; public Form1() { InitializeComponent(); worker = new BackgroundWorker {WorkerReportsProgress = true}; worker.DoWork += StartUpdating; worker.ProgressChanged += UpdateLabel; worker.RunWorkerCompleted += ResetLabelColor; } private void StartUpdating(object sender, DoWorkEventArgs e) { var workerObject = (BackgroundWorker) sender; for (int x = 0; x < 15; x++) { workerObject.ReportProgress(0); Thread.Sleep(1000); } } private void UpdateLabel(object sender, ProgressChangedEventArgs e) { lblTime.Text = DateTime.Now.ToString("HH:mm:ss"); } private void ResetLabelColor(object sender, RunWorkerCompletedEventArgs e) { lblTime.ForeColor = SystemColors.ControlText; } private void cmdStart_Click(object sender, EventArgs e) { lblTime.ForeColor = Color.Red; worker.RunWorkerAsync(); } } Well, this got a little better (I think). At least I now have my simple for/next loop back. Unfortunately, I’m still dealing with event handlers spread throughout my code to co-ordinate all of this stuff in the right order. Time to look into the future. The async way Using the Async CTP, I can go back to much simpler code (WindowsApplication04 in the solution): private async void cmdStart_Click(object sender, EventArgs e) { lblTime.ForeColor = Color.Red; for (var x = 0; x < 15; x++) { lblTime.Text = DateTime.Now.ToString("HH:mm:ss"); await TaskEx.Delay(1000); } lblTime.ForeColor = SystemColors.ControlText; } This code will run just like the Timer or BackgroundWorker versions – fully responsive during the updates – yet is way easier to implement. In fact, it’s almost a line-for-line copy of the original version of this code. All of the async plumbing is handled by the compiler and the framework. My code goes back to representing the “what” of what I want to do, not the “how”. I urge you to download the Async CTP. All you need is .NET 4.0 and Visual Studio 2010 sp1 – no need to set up a virtual machine with the VS2011 beta (unless, of course, you want to dive right in to the C# 5.0 stuff!). Starting playing around with this today and see how much easier it will be in the future to write async-enabled applications.

Read the article
NUMA-aware placement of communication variables

- by Dave

For classic NUMA-aware programming I'm typically most concerned about simple cold, capacity and compulsory misses and whether we can satisfy the miss by locally connected memory or whether we have to pull the line from its home node over the coherent interconnect -- we'd like to minimize channel contention and conserve interconnect bandwidth. That is, for this style of programming we're quite aware of where memory is homed relative to the threads that will be accessing it. Ideally, a page is collocated on the node with the thread that's expected to most frequently access the page, as simple misses on the page can be satisfied without resorting to transferring the line over the interconnect. The default "first touch" NUMA page placement policy tends to work reasonable well in this regard. When a virtual page is first accessed, the operating system will attempt to provision and map that virtual page to a physical page allocated from the node where the accessing thread is running. It's worth noting that the node-level memory interleaving granularity is usually a multiple of the page size, so we can say that a given page P resides on some node N. That is, the memory underlying a page resides on just one node. But when thinking about accesses to heavily-written communication variables we normally consider what caches the lines underlying such variables might be resident in, and in what states. We want to minimize coherence misses and cache probe activity and interconnect traffic in general. I don't usually give much thought to the location of the home NUMA node underlying such highly shared variables. On a SPARC T5440, for instance, which consists of 4 T2+ processors connected by a central coherence hub, the home node and placement of heavily accessed communication variables has very little impact on performance. The variables are frequently accessed so likely in M-state in some cache, and the location of the home node is of little consequence because a requester can use cache-to-cache transfers to get the line. Or at least that's what I thought. Recently, though, I was exploring a simple shared memory point-to-point communication model where a client writes a request into a request mailbox and then busy-waits on a response variable. It's a simple example of delegation based on message passing. The server polls the request mailbox, and having fetched a new request value, performs some operation and then writes a reply value into the response variable. As noted above, on a T5440 performance is insensitive to the placement of the communication variables -- the request and response mailbox words. But on a Sun/Oracle X4800 I noticed that was not the case and that NUMA placement of the communication variables was actually quite important. For background an X4800 system consists of 8 Intel X7560 Xeons . Each package (socket) has 8 cores with 2 contexts per core, so the system is 8x8x2. Each package is also a NUMA node and has locally attached memory. Every package has 3 point-to-point QPI links for cache coherence, and the system is configured with a twisted ladder "mobius" topology. The cache coherence fabric is glueless -- there's not central arbiter or coherence hub. The maximum distance between any two nodes is just 2 hops over the QPI links. For any given node, 3 other nodes are 1 hop distant and the remaining 4 nodes are 2 hops distant. Using a single request (client) thread and a single response (server) thread, a benchmark harness explored all permutations of NUMA placement for the two threads and the two communication variables, measuring the average round-trip-time and throughput rate between the client and server. In this benchmark the server simply acts as a simple transponder, writing the request value plus 1 back into the reply field, so there's no particular computation phase and we're only measuring communication overheads. In addition to varying the placement of communication variables over pairs of nodes, we also explored variations where both variables were placed on one page (and thus on one node) -- either on the same cache line or different cache lines -- while varying the node where the variables reside along with the placement of the threads. The key observation was that if the client and server threads were on different nodes, then the best placement of variables was to have the request variable (written by the client and read by the server) reside on the same node as the client thread, and to place the response variable (written by the server and read by the client) on the same node as the server. That is, if you have a variable that's to be written by one thread and read by another, it should be homed with the writer thread. For our simple client-server model that means using split request and response communication variables with unidirectional message flow on a given page. This can yield up to twice the throughput of less favorable placement strategies. Our X4800 uses the QPI 1.0 protocol with source-based snooping. Briefly, when node A needs to probe a cache line it fires off snoop requests to all the nodes in the system. Those recipients then forward their response not to the original requester, but to the home node H of the cache line. H waits for and collects the responses, adjudicates and resolves conflicts and ensures memory-model ordering, and then sends a definitive reply back to the original requester A. If some node B needed to transfer the line to A, it will do so by cache-to-cache transfer and let H know about the disposition of the cache line. A needs to wait for the authoritative response from H. So if a thread on node A wants to write a value to be read by a thread on node B, the latency is dependent on the distances between A, B, and H. We observe the best performance when the written-to variable is co-homed with the writer A. That is, we want H and A to be the same node, as the writer doesn't need the home to respond over the QPI link, as the writer and the home reside on the very same node. With architecturally informed placement of communication variables we eliminate at least one QPI hop from the critical path. Newer Intel processors use the QPI 1.1 coherence protocol with home-based snooping. As noted above, under source-snooping a requester broadcasts snoop requests to all nodes. Those nodes send their response to the home node of the location, which provides memory ordering, reconciles conflicts, etc., and then posts a definitive reply to the requester. In home-based snooping the snoop probe goes directly to the home node and are not broadcast. The home node can consult snoop filters -- if present -- and send out requests to retrieve the line if necessary. The 3rd party owner of the line, if any, can respond either to the home or the original requester (or even to both) according to the protocol policies. There are myriad variations that have been implemented, and unfortunately vendor terminology doesn't always agree between vendors or with the academic taxonomy papers. The key is that home-snooping enables the use of a snoop filter to reduce interconnect traffic. And while home-snooping might have a longer critical path (latency) than source-based snooping, it also may require fewer messages and less overall bandwidth. It'll be interesting to reprise these experiments on a platform with home-based snooping. While collecting data I also noticed that there are placement concerns even in the seemingly trivial case when both threads and both variables reside on a single node. Internally, the cores on each X7560 package are connected by an internal ring. (Actually there are multiple contra-rotating rings). And the last-level on-chip cache (LLC) is partitioned in banks or slices, which with each slice being associated with a core on the ring topology. A hardware hash function associates each physical address with a specific home bank. Thus we face distance and topology concerns even for intra-package communications, although the latencies are not nearly the magnitude we see inter-package. I've not seen such communication distance artifacts on the T2+, where the cache banks are connected to the cores via a high-speed crossbar instead of a ring -- communication latencies seem more regular.

Read the article
first install for windows eight.....da beta

- by raysmithequip

The W8 preview is now installed and I am enjoying it. I remember the learning curve of my first unix machine back in the eighties, this ain't that.It is normal for me to do the first os install with a keyboard and low end monitor...you never know what you'll encounter out in the field. The OS took like a fish to water. I used a low end INTEL motherboard dp55w I gathered on the cheap, an 1157 i5 from the used bin a pair of 6 gig ddr3 sticks, a rosewell 550 watt power supply a cheap used twenty buck sub 200g wd sata drive, a half working dvd burner and an asus fanless nvidia vid card, not a great one but Sub 50.00 on newey eggey...I did have to hunt the ms forums for a key and of course to activate the thing, if dos would of needed this outmoded ritual, we would still be on cpm and osborne would be a household name, of course little do people know that this ritual was common as far back as the seventies on att unix installs....not, but it was possible, I used to joke about when I ran a bbs, what hell would of been wrought had dos 3.2 machines been required to dial into my bbs to send fido mail to ms and wait for an acknowledgement. All in all the thing was pushing a seven on the ms richter scale, not including the vid card, sadly it came in at just a tad over three....I wanted to evaluate it for a possible replacement on critical machines that in the past went down due to a vid card fan failure....you have no idea what a customer thinks when you show them a failed vid card fan..."you mean that little plastic piece of junk caused all this!!??!!!"...yea man. Some production machines don't need any sort of vid, I will at least keep it on the maybe list for those, MTBF is a very important factor, some big box stores should put percentage of failure rate within 24 month estimates on the outside of the carton for sure. And a warning that the power supplies are already at their limit. Let's face it, today even 550w can be iffy.A few neat eye candy improvements over the earlier windows is nice, the metro screen is nice, anyone who has used a newer phone recently will intuitively drag their fingers across the screen....lot of good that was with no mouse or touch screen though. Lucky me, I have been using windows since day one, I still have a copy of win 2.0 (and every other version) for no good reason. Still the old ix collection of disks is much larger, recompiling any kernal is another silly ritual, same machine, different day, same recompile...argh. Rh is my all time fav, mandrake was always missing something, like it rewrote the init file or something, novell is ok as long as you stay on the beaten path and of course ubuntu normally recompiles with the same errors consistantly....makes life easy that way....no errors on windows eight, just a screen that did not match the installed hardware, natuarally I alt tabbed right out of it, then hit the flag key to find the start menu....no start button. I miss the start button already. Keyboard cowboy funnin and I was browsing the harddrive, nothing stunning there, I like that, means I can find stuff. Only I can't find what I want, the start button....the start menu is that first screen for touch tablets. No biggie for useruser, that is where they will want to be, I can see that. Admins won't want to be there, it is easy enough to get the control panel a bazzilion other ways though, just not the start button. (see a pattern here?). Personally, from the keyboard I find it fun to hit the carets along the location bar at the top of the explorer screen with tabs and arrows and choose SHOW ALL CONTROL PANEL ITEMS, or thereabouts. Bottom line, I love seven and I'll love eight even more!...very happy I did not have to follow the normal rule of thumb (a customer watching me build a system and asking questions said "oh I get it, so every piece you put in there is basically a hundred bucks, right?)...ok, sure, pretty much, more or less, well, ya dude. It will be WAY past october till I get a real touch screen but I did pick up a pair of cheap tatungs so I can try the NEW main start screen, I parse a lot of folders and have a vision of how a pair of touch screens will be easier than landing a rover on mars. Ok. fine, they are way smallish, and I don't expect multitouch to work but we are talking a few percent of a new 21 inch viewsonic touch screen. Will this OS be a game changer? I don't know. Bottom line with all the pads and droids in the world, it is more of a catch up move at first glance. Not something ms is used to. An app store? I can see ms's motivation, the others have it. I gather there will not be gadgets there, go ahead and see what ms did to the once populated gadget page...go ahead, google gadgets and take a gander, used to hundreds of gadgets, they are already gone. They replaced gadgets? sort of, I'll drop that, it's a bit of a sore point for me. More of interest was what happened when I downloaded stuff off codeplex and some other normal programs that I like, like orbitron, top o' my list!!...cardware it is...anyways, click on the exe, get a screen, normal for windows, this one indicated that I was not running a normal windows program and had a button for exit the install, naw, I hit details, a hidden run program anyways came into view....great, my path to the normal windows has detected a program tha.....yea ok, acl is on, fine, moving along I got orbitron installed in record time and was tracking the iss on the newest Microsoft OS, beta of course, felt like the first time I setup bsd all those year ago...FUN!!...I suppose I gotta start to think about budgeting for the real os when it comes out in october, by then I should have a rasberry pi and be done with fedora remixed. Of course that sounds like fun too!! I would use this OS on a tablet or phone. I don't like the idea of being hearded to an app store, don't like that on anything, we are americans and want real choices not marketed hype, lest you are younger with opm (other peoples money). This os would be neat on a zune, but I suspect the zune is a gonner, I am rooting for microsoft, after all their default password is not admin anymore, nor alpine, it's blank. Others force a password, my first fawn password was so long I could not even log into it with the password in front of me, who the heck uses %$# anyways, and if I was writing a brute force attack what the heck kinda impasse is that anyways at .00001 microseconds of a code execution cycle (just a non qualified number, not a real clock speed)....AI is where it will be before too long, MS is on that path, perhaps soon someone will sit down and write an app for the kinect that watches your eyes while you scan the new main start screen, clicking on the big E icon when you blink.....boy is that going to be fun!!!! sure. Blink,dammit,blink,dammit...... OPM no doubt.I like windows eight, we are moving forwards, better keep a close eye on ubuntu. The real clinch comes when open source becomes paid source......don't blink, I already see plenty of very expensive 'ix apps, some even in app stores already. more to come.......

Read the article
DevConnections Spring 2010 Speaker Evals and Tips

As a conference speaker, I always look forward to hearing from attendees whether they felt my sessions were valuable and worth their time. Its always gratifying get a high score, but of course its the (preferably constructive) criticism thats key to continued improvement. Im by no means the best technical presenter around, and Im always looking for ways to improve. Ive recently spoken at a few events, including TechEd and an Ohio event called Stir Trek. DevConnections was actually back in April, but theyre just getting their final evals out to speakers. TechEd, of course, does online evals so immediately after your talks you can see what people think. Ill try and post my TechEd evals in the next week or so. I gave 3 talks at DevConnections Spring 2010 / VS2010 Launch which I discussed in this previous blog post. In this follow-up, Im just going to share some eval info and my thoughts on it, albeit a couple of months later. Pragmatic ASP.NET Tips, Tricks, and Tools Evals Turned In: 27 Overall Eval: 3.74 Average Score: 3.47 89% found the technical level Just Right. 7.4% thought it was too basic (3.6% did not respond). Since nobody thought the content was Too complex, I could perhaps have added some more complex material, but having about 90% say its Just Right is pretty good. 92% said at least 50% of the material was new to them. 36% said 75% or more was new. Thats also pretty good, I think. 77.8% can use the information immediately; 15% can use it within 2-6 months (7.2 % no response). Overall 78% rated the session Excellent, 18% Good, 4% Fair. All comments (9): Steve did a great job Excellent session! It was good. Im now super excited to attend Steves other sessions later today. Very useful. One of the best speakers here. Bring him back to future conferences please. Continue to have this session with new and old stuff. I always find something I did not know about. Excellent! This was the best session Ive seen all week. Did not increase font on all pages could not see. For Steve to have had more sessions. Note to self make the fonts bigger across the board. Otherwise, this is all good for my ego. :) This is always a very popular session and one I really enjoy giving. Tips and Tricks talks are pretty easy because you dont have to go in depth with any particular thing, and theyre almost always with existing technology so youre not dealing with betas, lack of documentation, and other issues. Its an easy session to do well, in my experience, and one which I think attendees definitely appreciate. Whats New in ASP.NET MVC 2 Evals Turned In: 23 Overall Eval: 3.77 Average Score: 3.47 (wow, I cant believe I scored better on this talk than the tips and tricks talk, which Ive given many times and was more excited about) 96% found the technical level Just Right. 90% found 50% or more of the material to be new. 43% can use the info immediately, and another 43% can use it within 2-6 months I guess that speaks to adoption rates of MVC 2 among my attendees Overall 74% said the session was Excellent, 22% Good. 4% No Response. All Comments (6): Great job, thank you. Great speaker! Really good, a little lost in the code at some points, but great information. Speaker needs to repeat questions from audience for everyone to hear. Exceeded my expectations. Great speaker, very informative. I really do try to religiously repeat questions from the audience for everyone to hear, but obviously I didnt do it 100% of the time. Note to self remember to repeat questions. That and making fonts big are really basic speaker best practices, which just goes to prove that fundamentals are always something that can be perfected. SOLIDify Your ASP.NET MVC 2 Application Evals Turned In: 8 (!) Overall Eval: 3.63 Average Score: 3.47 As I recall this was one of the last talks of the day / show, which might account for the low number of evals turned in. I dont recall speaking to an empty room for this talk, although it certainly wasnt as crowded as the tips and tricks talk. 100% found the technical level Just Right. 100% found at least half the material new. 62.5% can use it at once and 37.5% within 2-6 months. 62.5% rated the session Excellent overall; 37.5% Good. Im thinking there were 5 evals with all 4s checked and 3 with all 3s checked (4 = Excellent, 3 = Good) All Comments (3): This covered many topics Ive read about recently, and it helped reinforce them. It was a nice overview of the solid principle, but I thought there might be specifics for MVC2. I am glad there is not. Move a little slower. Ok, so another fundamental dont go too fast. Looks like I got one fundamental tip from the comments of each talk. My Take-Aways Remember the fundamentals. Its worth going through a checklist prior to presenting to make sure these things are fresh in your mind. Increase all font sizes. Repeat all questions from audience members without microphones (this is also a great way to stall for time, btw). Resist the urge to move too quickly especially if youre nervous or short of time. Writing this up in a blog post also further reinforces these fundamentals for me, which is one of the main reasons why I do it I retain things better when I write them, and even moreso when I write them for public consumption since I have to really think about what Im saying. And maybe a few of you find this interesting or helpful, which is a bonus. Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

Read the article
Top 10 Browser Productivity Tips

- by Renso

Originally posted on: http://geekswithblogs.net/renso/archive/2013/10/14/top-10-browser-productivity-tips.aspxYou don’t have to be a geek to be a productive browser user. The tips below have been selected by actions users take most of the time to navigate a web-site but use long-standing keyboard or mouse actions to get them done, when there are keyboard short-cuts you can use instead. Since you hands are already on the keyboard it is almost always faster to sue a keyboard shortcut to get something done that you usually used the mouse for. For example right-clicking on something to copy it and then doing to same for pasting something is very time consuming, keyboard shortcuts have been created that simplify the task. All it takes are a few memory brain cells to remember them. Here are the tips, in no particular order: Tip 1 Hold down the spacebar on your keyboard to page to the end of your web page rather than using your mouse. This is really a slow way of doing it. If you want to page one page at a time, hit the spacebar once, and again to page again. But if you want to page all the way to the end of the web page simply hit Ctrl+End (that is hold down the Ctrl key and hit the End button on your keyboard). To get to the top of your web page, simply hit Ctrl + Home to go all the way to the top of your web page. Tip 2 Where are my downloads? Some folks run downloads again-and-again because they do not know where the last one went and they do not see the popup, or browser note on their web page in the footer, etc. Simply hit Ctrl+J. Works in most browsers. Tip 3 Selecting a US state from a drop down box. Don’t use the mouse, takes just way too long to scroll. When you tab to the drop down box or click on it with your mouse, simply hit the first character of the state and it will be selected. For Texas for example hit the letter “T” twice on your keyboard to get to it. The same concept can be applied to any drop down box that is alphabetical or numerically sorted. Tip 4 Fixing spelling errors. All modern-day browsers support this now. You see the red wavy lines underscoring a word, yes it is a spelling error. How do you fix it? Don’t overtype it or try and fix it manually, fist right-click on it and a list of suggestions comes up. If it does not show up, like my name “Renso” and you know how to spell your name as in this example, look further down the list of options (the little window popup that appears when you right click) and you should see an option to “Add to Dictionary”. Be warned, when you add it, it only adds it to the browser you’re using’s dictionary. If you use Google Chrome, Firefox and IE, each one will have their own list. Tip 5 So you have trouble seeing the text on the screen. Or you are looking at a photo, for example in Facebook. You want to zoom in to read better or zoom into a photo a bit more. Hit Ctrl++ (hold down Ctrl key and hit the plus key – actually it’s the equal key but it is easier to remember that it is plus for bigger). Hit the minus to zoom out. Now you can’t remember what the original size was since you were so excited to hit it 20 times, or was that 21… Simply hit Ctrl+0 (that is zero) and it will reset it to the default. Tip 6 So you closed a couple of tabs in your browser. Suddenly you remember something you wanted to double-check something on one of the tabs, you cannot remember the URL ad the tab is gone forever, or is it? Simply hit Ctrl+Shift+t and it will bring back your tabs one by one each time you click the T. This has also been a great way for me to quickly close some tabs because I don’t want my boss to see I’m shopping and then hitting Ctrl+Shift+t to quickly get it back and complete my check-put and purchase. Or, for parents, when you walk into your daughter’s room and you see she quickly clicks and closes a window/tab in here browser. Not to worry my little darling, daddy will Ctrl+Shift+t and see what boys on Facebook you were talking too… Tip 7 The web browser is frozen on your PC/Laptop/Whatever, in this example it may be your Internet Explorer browser. I don’t mention Firefox or Chrome here because it probably never happens in their world. You cannot close it, it won’t respond to anything you have done s far except for the next step you are about to take, which is throw your two-day old coffee on your keyboard. This happens especially on sites that want to force you to complete a purchase order. Hit Ctrl+Alt+Del on your keyboard on any version of windows, select TASK MANAGER. In the First Tab, which is the Process Tab, look for the item in question. In this example you should see Internet Explorer. Right-click it and select “End Task”. It will force the thread out of memory and terminate that process. You can of course do this with any program running under your account. Tip 8 This is a personal favorite of mine. To select words in the paragraph without using the mouse. You don’t want to select one character at a time like when you use the Ctrl+arrows as it can be very slow if you want to select a lot of text. You also want to select whole words. Simply use the Ctrl+Shift_arrow (right or left depending which direction you want to go. Tip 9 I was a bit reluctant to add this one, but being in the professional services industry still come across many-a-folk that simply can’t copy-and-paste them-all text or images that reside on them screens, y’all. Ctrl+c to copy and Ctrl+v to paste it. Works a lot faster than using the mouse. You may be asking: “Well why in the devil did they not use Ctrl+p for paste…. because that is for printing. This is of course not limited to the browser world, it applies to almost any piece of software running on PC or Mac. Go try it on an image on your browser, right-click it and select copy. Open a word document and Ctrl+v to paste the image in there. Please consider copyright laws. Tip 10 Getting rid of annoying ads. Now this only works when you load a web page, meaning when you get back to the same page later you will have to do this again and you will need to learn a tool to do it, WELL WORTH IT. For example, I use GrooveShark to listen to music but I don’t like the ads they show. Install a tool like Firebug for Firefox or use the Ctrl+Shift+I on Chrome to bring up the developer toolbar. Shows at the bottom of the page. With Firefox, once you have installed Firebug as an add-on, a yellow bug should appear on the top right-hand-side of your browser, click on it to display the developer toolbar. You will need to learn how to use it, but once you know how to select an item/section on the window (usually just right-click the add you don’t want to see and select “Inspect Element”, the developer toolbar will appear (if not already there)) and then simply hit delete and it will remove the add from the screen. If you don’t know HTML you may need to play with it a bit, but once you understand how it works can open up a whole new world for you on how web pages actually work. If you can think of any others that have saved you a ton of time please let me know so I can add them to a top 99 list.

Read the article
5 Ways Android Still Disappoints (Me)

- by TStewartDev

Let me make this clear: I'm annoyed with Apple. I don't like their current policies and I don't like where Steve Jobs is taking the company. In general, I don't like it when any one company gets too much control in a market. When that happens, the leading company dictates the game and as consumers, our options all but disappear. That said, I'm still going to buy a new iPhone next week. My Apple-hating friends seem to desperately want me to go Android instead, but frankly, it's not good enough for me, and here are the reasons why. The Modern WinMo One of the reasons that Microsoft has identified for Windows Mobile's rapid decline is the breadth of hardware. They exercised little control over manufacturer's implementations. In theory, that sounds great. We as consumers have lots of choice. In practice, though, it meant among other things that updates to the devices were left up to the manufacturers. As a result, that rarely happened. (I'm still bitter at Toshiba for leaving me hanging back in 2002.) And now, Google is doing the same thing with Android. Case in point: my wife has a Motorola Backflip that we bought in April. It was released in March. Motorola says it will get Android 2.1 "sometime in Q3". Great. Meanwhile, I pull down the latest version of iPhone OS (now iOS) and install it the same day it's released. You may say that I can't judge Android by one lazy manufacturer. Yup, I sure can. With Apple, my original iPhone has been supported perfectly for 3 years. With Android, I will have to wait for upgrades after Google releases them, possibly indefinitely. Not cool. AT&T We signed a new contract with AT&T in April to get my wife's phone. I've had a reasonable experience with them. I don't imagine my experience with Verizon would be any better, and I'm relatively confident that Sprint doesn't have the coverage it takes to work well for us. The fact is, AT&T, for whatever reason, doesn't have jack for Android phones. May not be Android's fault, but it's still a shortcoming that prevents me from having it just like the iPhone's exclusivity keeps some folks on other networks from having it. Innovation? What Innovation? Android has a nice dashboard and a great notification system and… nothing else original. I keep reading about how disappointing the iPhone is nowadays. "It has no innovation," people say. Who does? Android has modeled its behavior after the iPhone. That's fine, but if all you've got is a similar product and I'm invested both skill-wise and app-wise in my current platform, why should I change? Microsoft's new Windows Phone 7 looks somewhat innovative, and I'm pretty excited to see what they'll bring to the table, but that's another six months away, at least. I've got a 3 year old phone that has some annoying issues now (thanks to recent encounters with water). I need a new phone now. Is This Going to Work? There's no shortage of criticism of Apple over its App Store policies, and I've vented my own anger about it. However, I will give them credit: their screening of apps has done a great job of weeding out the crap and gives an excellent indication that the app will work on my device. How about Android? Nope. It might work on your phone. Maybe. You'll have to try it to see. Get burned by it? Well, write a nasty review to try to keep others from making the mistake you did. If you don't mind doing that stuff, then Android is the platform for you. Personally, I'd rather have a receptionist screening out the telemarketing and survey calls than hang up on them myself, but that's your call. Slow, Slowing, Slower All this yapping about multitasking. This is an area I've been on Apple's side from the beginning. Sorry folks, but this is the number one reason I hated Windows Mobile: the longer you use it, the slower it gets because it doesn't kill apps. I'm with Steve Jobs on this one: if you see a task manager, we're doing it wrong. I don't want to have to manually kill apps. I hate doing that on Windows let alone on a mobile device. To me, priority one should be keeping the device speedy. Waiting for your device to respond is unacceptable. Bonus! Taken from iPhone Letdown? 8 Things Apple Didn't Announce, here are my responses: 4G Yeah, let me know if your area actually has it. I live in Lincoln, Nebraska. No carrier is going to have 4G here for at least 3 years. Meanwhile, you still get to pay for it. Yay! Cloud iTunes/OTA Sync You got me here. Of course, whether or not your Android device will be able to do it is always a good question. 3G Video Chat You got me here, too. I'm sure you spent countless hours in front of your phone with video chat. Also, I can't wait for the "No Video Chat While Driving" laws. Mobile Hotspot This is a neat feature, but as the author points out, it's left up to the carrier whether to implement it or not. Pretty sure any Android phones that come to AT&T won't have this enabled in the foreseeable future. Is Verizon even allowing this? I just figured Sprint was because they're failing so hard at keeping customers. Free MobileMe I use Google's services with my iPhone. The only people I know who use MobileMe are Apple fanboys and fangirls. If you choose to pay for a service that you can get for free, that's your decision, not Apple's. Voice Input Voice input has been available on phones (even "dumb" phones) for years now. iPhone does have the ability, though limited. Why don't I hear people telling their phones what to do? Maybe because it's still easier to use your fingers than talk to it. Get back to me when this becomes an important feature. Free Navigation Maybe this will be a bigger deal to me now that I'm getting a phone with GPS, but when using my buddy's 3gs, Google maps has worked just fine. Maybe I just don't trust turn-by-turn navigation enough to want it. Dashboard The only legitimate complaint on this list, to me. iPhone's home screen is pathetic, doubly so for the iPad. What a waste of perfectly usable space. I also want to add notifications to this list. Android's notification panel is far superior to the iPhone's. I don't want to hunt all over my screen to find little red dots. Put 'em in one place, Apple.

Read the article
Corsair Hackers Reboot

It wasn't easy for me to attend but it was absolutely worth to go. The Linux User Group of Mauritius (LUGM) organised another get-together for any open source enthusiast here on the island. Strangely named "Corsair Hackers Reboot" but it stands for a positive cause: "Corsair Hackers Reboot Event A collaborative activity involving LUGM, UoM Computer Club, Fortune Way Shopping Mall and several geeks from around the island, striving to put FOSS into homes & offices. The public is invited to discover and explore Free Software & Open Source." And it was a good opportunity for me and the kids to visit the east coast of Mauritius, too. Perfect timing It couldn't have been better... Why? Well, for two important reasons (in terms of IT): End of support for Microsoft Windows XP - 08.04.2014 Release of Ubuntu 14.04 Long Term Support - 17.04.2014 Quite funnily, those two IT dates weren't the initial reasons and only during the weeks of preparations we put those together. And therefore it was even more positive to promote the use of Linux and open source software in general to a broader audience. Getting there ... Thanks to the new motor way M3 and all the additional road work which has been completed recently it was very simple to get across the island in a very quick and relaxed manner. Compared to my trips in the early days of living in Mauritius (and riding on a scooter) it was very smooth and within less than an hour we hit Centrale de Flacq. Well, being in the city doesn't necessarily mean that one has arrived at the destination. But thanks to modern technology I had a quick look on Google Maps, and we finally managed to get a parking behind the huge bus terminal in Flacq. From there it was just a short walk to Fortune Way. The children were trying to count the number of buses... Well, lots and lots of buses - really impressive actually. What was presented? There were different areas set up. Right at the entrance one's attention was directly drawn towards the elevated hacker's stage. Similar to rock stars performing their gig there was bunch of computers, laptops and networking equipment in order to cater the right working conditions for coding/programming challenge(s) on the one hand and for the pen-testing or system hacking competition on the other hand. Personally, I was very impresses that actually Nitin took care of the pen-testing competition. He hardly started one year back with Linux in general, and Kali Linux specifically. Seeing his personal development from absolute newbie to a decent Linux system administrator within such a short period of time, is really impressive. His passion to open source software made him a living. Next, clock-wise seen, was the Kid's Corner with face-painting as the main attraction. Additionally, there were numerous paper print outs to colour. Plus a decent workstation with the educational suite GCompris. Of course, my little ones were into that. They already know GCompris since a while as they are allowed to use it on an IGEL thin client terminal here at home. To simplify my life, I set up GCompris as full-screen guest session on the server, and they can pass the login screen without any further obstacles. And because it's a thin client hooked up to a XDMCP remote session I don't have to worry about the hardware on their desk, too. The next section was the main attraction of the event: BYOD - Bring Your Own Device Well, compared to the usual context of BYOD the corsairs had a completely different intention. Here, you could bring your own laptop and a team of knowledgeable experts - read: geeks and so on - offered to fully convert your system on any Linux distribution of your choice. And even though I came later, I was told that the USB pen drives had been in permanent use. From being prepared via dd command over launching LiveCD session to finally installing a fresh Linux system on bare metal. Most interestingly, I did a similar job already a couple of months ago, while upgrading an existing Windows XP system to Xubuntu 13.10. So far, the female owner is very happy and enjoys her system almost every evening to go shopping online, checking mails, and reading latest news from the Anime world. Back to the Hackers event, Ish told me that they managed approximately 20 conversion during the day. Furthermore, Ajay and others gladly assisted some visitors with some tricky issues and by the end of the day you can call is a success. While I was around, there was a elderly male visitor that got a full-fledged system conversion to a Linux system running completely in French language. A little bit more to the centre it was Yasir's turn to demonstrate his Arduino hardware that he hooked up with an experimental electrical circuit board connected to an LCD matrix display. That's the real spirit of hacking, and he showed some minor adjustments on the fly while demo'ing the system. Also, very interesting there was a thermal sensor around. Personally, I think that platforms like the Arduino as well as the Raspberry Pi have a great potential at a very affordable price in order to bring a better understanding of electronics as well as computer programming to a broader audience. It would be great to see more of those experiments during future activities. And last but not least there were a small number of vendors. Amongst them was Emtel - once again as sponsor of the general internet connectivity - and another hardware supplier from Riche Terre shopping mall. They had a good collection of Android related gimmicks, like a autonomous web cam that can convert any TV with HDMI connector into an online video chat system given WiFi. It's actually kind of awesome to have a Skype or Google hangout video session on the big screen rather than on the laptop. Some pictures of the event LUGM: Great conversations on Linux, open source and free software during the Corsair Hackers Reboot LUGM: Educational workstation running GCompris suite attracted the youngest attendees of the day. Of course, face painting had to be done prior to hacking... LUGM: Nadim demoing some Linux specifics to interested visitors. Everyone was pretty busy during the whole day LUGM: The hacking competition, here pen-testing a wireless connection and access point between multiple machines LUGM: Well prepared workstations to be able to 'upgrade' visitors' machines to any Linux operating system Final thoughts Gratefully, during the preparations of the event I was invited to leave some comments or suggestions, and the team of the LUGM did a great job. The outdoor banner was a eye-catcher, the various flyers and posters for the event were clearly written and as far as I understood from the quick chats I had with Ish, Nadim, Nitin, Ajay, and of course others all were very happy about the event execution. Great job, LUGM! And I'm already looking forward to the next Corsair Hackers Reboot event ... Crossing fingers: Very soon and hopefully this year again :) Update: In the media The event had been announced in local media, too. L'Express: Salon informatique: Hacking Challenge à Flacq

Read the article
Why people don't patch and upgrade?!?

- by Mike Dietrich

Discussing the topic "Why Upgrade" or "Why not Upgrade" is not always fun. Actually the arguments repeat from customer to customer. Typically we hear things such as: A PSU or Patch Set introduces new bugs A new PSU or Patch Set introduces new features which lead to risk and require application verification Patching means risk Patching changes the execution plans Patching requires too much testing Patching is too much work for our DBAs Patching costs a lot of money and doesn't pay out And to be very honest sometimes it's hard for me to stay calm in such discussions. Let's discuss some of these points a bit more in detail. A PSU or Patch Set introduces new bugsWell, yes, that is true as no software containing more than some lines of code is bug free. This applies to Oracle's code as well as too any application or operating system code. But first of all, does that mean you never patch your OS because the patch may introduce new flaws? And second, what is the point of saying "it introduces new bugs"? Does that mean you will never get rid of the mean issues we know about and we fixed already? Scroll down from MOS Note:161818.1 to the patch release you are on, no matter if it's 10.2.0.4 or 11.2.0.3 and check for the Known Issues And Alerts.Will you take responsibility to know about all these issues and refuse to upgrade to 11.2.0.4? I won't. A new PSU or Patch Set introduces new featuresOk, we can discuss that. Offering new functionality within a database patch set is a dubious thing. It has advantages such as in 11.2.0.4 where we backported Database Redaction to. But this is something you will only use once you have an Advanced Security license. I interpret that statement I've heard quite often from customers in a different way: People don't want to get surprises such as new behaviour. This certainly gives everybody a hard time. And we've had many examples in the past (SESSION_CACHED_CURSROS in 10.2.0.4, _DATAFILE_WRITE_ERRORS_CRASH_INSTANCE in 11.2.0.2 and others) where those things weren't documented, not even in the README. Thanks to many friends out there I learned about those as well. So new behaviour is the topic people consider as risky - not really new features. And just to point this out: A PSU never brings in new features or new behaviour by definition! Patching means riskDoes it really mean risk? Yes, there were issues in the past (and sometimes in the present as well) where a patch didn't get installed correctly. But personally I consider it way more risky to not patch. Keep that in mind: The day Oracle publishes an PSU (or CPU) containing security fixes all the great security experts out there go public with their findings as well. So from that day on even my grandma can find out about those issues and try to attack somebody. Now a lot of people say: "My database does not face the internet." And I will answer: "The enemy is sitting already behind your firewalls. And knows potentially about these things." My statement: Not patching introduces way more risk to your environment than patching. Seriously! Patching changes the execution plansDo they really? I agree - there's a very small risk for this happening with Patch Sets. But not with PSUs or CPUs as they contain no optimizer fixes changing behaviour (but they may contain fixes curing wrong-query-result-bugs). But what's the point of a changing execution plan? In Oracle Database 11g it is so simple to be prepared. SQL Plan Management is a free EE feature - so once that occurs you'll put the plan into the Plan Baseline. Basta! Yes, you wouldn't like to get such surprises? Than please use the SQL Performance Analyzer (SPA) from Real Application Testing and you'll detect that easily upfront in minutes. And not to forget this, a plan change can also be very positive!Yes, there's a little risk with a database patchset - and we have many possibilites to detect this before patching. Patching requires too much testingWell, does it really? I have seen in the past 12 years how people test. There are very different efforts and approaches on this. I have seen people spending a hell of money on licenses or on project team staffing. And I have seen people sailing blindly without any tests just going the John-Wayne-approach.Proper tools will allow you to test easily without too much efforts. See the paragraph above. We have used Real Application Testing in so many customer projects reducing the amount of work spend on testing by over 50%. But apart from that at some point you will have to stop testing. If you don't you'll get lost and you'll burn money. There's no 100% guaranty. You will have to deal with a little risk as reaching the final 5% of certainty will cost you the same as it did cost to reach 95%. And doing this will lead to abnormal long product cycles that you'll run behind forever. And this will cost even more money. Patching is too much work for our DBAsPatching is a lot of work. I agree. And it's no fun work. It's boring, annoying. You don't learn much from that. That's why you should try to automate this task. Use the Database's Lifecycle Management Pack. And don't cry about the fact that it costs money. Yes it does. But it will ease the process and you'll save a lot of costs as you don't waste your valuable time with patching. Or use Oracle Database 12c Oracle Multitenant and patch either by unplug/plug or patch an entire container database with all PDBs with one patch in one task. We have customer reference cases proofing it saved them 75% of time, effort and cost since they've used Lifecycle Management Pack. So why don't you use it? Patching costs a lot of money and doesn't pay outWell, see my statements in the paragraph above. And it pays out as flying with a database with 100 known critical flaws in it which are already fixed by Oracle (such as in the Oct 2013 PSU for Oracle Database 12c) will cost ways more in case of failure or even data loss. Bet with me? Let me finally ask you some questions. What cell phone are you using and which OS does it run? Do you have an iPhone 5 and did you upgrade already to iOS 7.0.3? I've just encountered on mine that the alarm (which I rely on when traveling) has gotten now a dependency on the physical switch "sound on/off". If it is switched to "off" physically the alarm rings "silently". What a wonderful example of a behaviour change coming in with a patch set. Will this push you to stay with iOS5 or iOS6? No, because those have security flaws which won't be fixed anymore. What browser are you surfing with? Do you use Mozilla 3.6? Well, congratulations to all the hackers. It will be easy for them to attack you and harm your system. I'd guess you have the auto updater on. Same for Google Chrome, Safari, IE. Right? -Mike The T.htmtableborders, .htmtableborders td, .htmtableborders th {border : 1px dashed lightgrey ! important;} html, body { border: 0px; } body { background-color: #ffffff; } img, hr { cursor: default }

Read the article
Why Is Vertical Resolution Monitor Resolution so Often a Multiple of 360?

- by Jason Fitzpatrick

Stare at a list of monitor resolutions long enough and you might notice a pattern: many of the vertical resolutions, especially those of gaming or multimedia displays, are multiples of 360 (720, 1080, 1440, etc.) But why exactly is this the case? Is it arbitrary or is there something more at work? Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites. The Question SuperUser reader Trojandestroy recently noticed something about his display interface and needs answers: YouTube recently added 1440p functionality, and for the first time I realized that all (most?) vertical resolutions are multiples of 360. Is this just because the smallest common resolution is 480×360, and it’s convenient to use multiples? (Not doubting that multiples are convenient.) And/or was that the first viewable/conveniently sized resolution, so hardware (TVs, monitors, etc) grew with 360 in mind? Taking it further, why not have a square resolution? Or something else unusual? (Assuming it’s usual enough that it’s viewable). Is it merely a pleasing-the-eye situation? So why have the display be a multiple of 360? The Answer SuperUser contributor User26129 offers us not just an answer as to why the numerical pattern exists but a history of screen design in the process: Alright, there are a couple of questions and a lot of factors here. Resolutions are a really interesting field of psychooptics meeting marketing. First of all, why are the vertical resolutions on youtube multiples of 360. This is of course just arbitrary, there is no real reason this is the case. The reason is that resolution here is not the limiting factor for Youtube videos – bandwidth is. Youtube has to re-encode every video that is uploaded a couple of times, and tries to use as little re-encoding formats/bitrates/resolutions as possible to cover all the different use cases. For low-res mobile devices they have 360×240, for higher res mobile there’s 480p, and for the computer crowd there is 360p for 2xISDN/multiuser landlines, 720p for DSL and 1080p for higher speed internet. For a while there were some other codecs than h.264, but these are slowly being phased out with h.264 having essentially ‘won’ the format war and all computers being outfitted with hardware codecs for this. Now, there is some interesting psychooptics going on as well. As I said: resolution isn’t everything. 720p with really strong compression can and will look worse than 240p at a very high bitrate. But on the other side of the spectrum: throwing more bits at a certain resolution doesn’t magically make it better beyond some point. There is an optimum here, which of course depends on both resolution and codec. In general: the optimal bitrate is actually proportional to the resolution. So the next question is: what kind of resolution steps make sense? Apparently, people need about a 2x increase in resolution to really see (and prefer) a marked difference. Anything less than that and many people will simply not bother with the higher bitrates, they’d rather use their bandwidth for other stuff. This has been researched quite a long time ago and is the big reason why we went from 720×576 (415kpix) to 1280×720 (922kpix), and then again from 1280×720 to 1920×1080 (2MP). Stuff in between is not a viable optimization target. And again, 1440P is about 3.7MP, another ~2x increase over HD. You will see a difference there. 4K is the next step after that. Next up is that magical number of 360 vertical pixels. Actually, the magic number is 120 or 128. All resolutions are some kind of multiple of 120 pixels nowadays, back in the day they used to be multiples of 128. This is something that just grew out of LCD panel industry. LCD panels use what are called line drivers, little chips that sit on the sides of your LCD screen that control how bright each subpixel is. Because historically, for reasons I don’t really know for sure, probably memory constraints, these multiple-of-128 or multiple-of-120 resolutions already existed, the industry standard line drivers became drivers with 360 line outputs (1 per subpixel). If you would tear down your 1920×1080 screen, I would be putting money on there being 16 line drivers on the top/bottom and 9 on one of the sides. Oh hey, that’s 16:9. Guess how obvious that resolution choice was back when 16:9 was ‘invented’. Then there’s the issue of aspect ratio. This is really a completely different field of psychology, but it boils down to: historically, people have believed and measured that we have a sort of wide-screen view of the world. Naturally, people believed that the most natural representation of data on a screen would be in a wide-screen view, and this is where the great anamorphic revolution of the ’60s came from when films were shot in ever wider aspect ratios. Since then, this kind of knowledge has been refined and mostly debunked. Yes, we do have a wide-angle view, but the area where we can actually see sharply – the center of our vision – is fairly round. Slightly elliptical and squashed, but not really more than about 4:3 or 3:2. So for detailed viewing, for instance for reading text on a screen, you can utilize most of your detail vision by employing an almost-square screen, a bit like the screens up to the mid-2000s. However, again this is not how marketing took it. Computers in ye olden days were used mostly for productivity and detailed work, but as they commoditized and as the computer as media consumption device evolved, people didn’t necessarily use their computer for work most of the time. They used it to watch media content: movies, television series and photos. And for that kind of viewing, you get the most ‘immersion factor’ if the screen fills as much of your vision (including your peripheral vision) as possible. Which means widescreen. But there’s more marketing still. When detail work was still an important factor, people cared about resolution. As many pixels as possible on the screen. SGI was selling almost-4K CRTs! The most optimal way to get the maximum amount of pixels out of a glass substrate is to cut it as square as possible. 1:1 or 4:3 screens have the most pixels per diagonal inch. But with displays becoming more consumery, inch-size became more important, not amount of pixels. And this is a completely different optimization target. To get the most diagonal inches out of a substrate, you want to make the screen as wide as possible. First we got 16:10, then 16:9 and there have been moderately successful panel manufacturers making 22:9 and 2:1 screens (like Philips). Even though pixel density and absolute resolution went down for a couple of years, inch-sizes went up and that’s what sold. Why buy a 19″ 1280×1024 when you can buy a 21″ 1366×768? Eh… I think that about covers all the major aspects here. There’s more of course; bandwidth limits of HDMI, DVI, DP and of course VGA played a role, and if you go back to the pre-2000s, graphics memory, in-computer bandwdith and simply the limits of commercially available RAMDACs played an important role. But for today’s considerations, this is about all you need to know. Have something to add to the explanation? Sound off in the the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.

Read the article
I Clobbered a Leopard with a Window Last Night

- by D'Arcy Lussier

I’ve had my 15” Mac Book Pro for a little over a year now, and its hands-down the best laptop I’ve ever owned…hardware wise. And I tried, I really really tried, to like OSX. I even bought Parallels so I could run Windows 7 and all my development tools while still trying to live in an OSX world. But in the end, I missed Windows too much. There were just too many shortcomings with OSX that kept me from being productive. For one thing, Office for Mac is *not* Office for Windows. The applications are written by different teams, and Excel on the Mac is just different enough to be painful. The VM experience was adequate, but my MBP would heat up like crazy when running it and the experience trying to get Windows apps to interact with an OSX file system was awkward. And I found I was in the VM more than I thought I’d be. iMovie is not as easy to use for doing simple movie editing as Windows Movie Maker. There’s no free blog editing software for OSX that’s on par with Windows Live Writer. And really, all I was using OSX for was Twitter (which I can use a Windows client for) and web browsing (also something Windows can provide obviously). So I had to ask myself – why am I forcing myself to use an operating system I don’t like, on a laptop that can support Windows 7? And so I paved my MBP and am happily running Windows 7 on it…and its fantastic! All the good stuff with the hardware is still there with the goodness of Win 7. Happy happy. I did run into some snags doing this though, and that’s really what this blog post is about – things to be aware of if you want to install Win 7 directly on your MBP metal. First, Ensure You Have Your Original Mac Install Disk This was a warning my buddy Dylan, who’s been running Win 7 on his MBP for a while now, gave me early on. The reason you need that original disk is that the hardware drivers you need are all located there. Apparently you can’t easily download them, so make sure you have them ahead of time. Second, Forget BootCamp The only reason you need BootCamp is if you still want the option to boot into OSX. If you don’t, then you don’t need BootCamp. In fact, you don’t even need BootCamp to install Win 7. What you *will* need though is a DVD with Win 7 burnt on it. Apple doesn’t support bootable USB drives. Well, actually they do for Mac Book Airs which don’t come with optical drives…but to get it working you’ll need to edit a system file of BootCamp so your make of MBP is included in an XML document, and even then you *still* are using BootCamp meaning you’ll be making an OSX partition. So don’t worry about BootCamp, just burn a Windows 7 disc, put it into the DVD drive, and restart your MBP. Third, Know The Secret Commands So after putting in the Windows 7 DVD and restarting your MBP, you’ll want to hold down the ‘C’ key during boot up. This tells the MBP that it should boot from the DVD drive instead of the hard drive. Interestingly, it appears you don’t have to do this if its the Mac OSX install disc (more on that in a second), but regardless – hold down C and Windows will start the install process. Next up is the partition process. You’ll notice that there’s a partition called ETI or something like that. This has to do with the drive format that Apple uses and how they partition their system drives. What I did – I blew it away! At first I didn’t, but I was told I couldn’t install Windows on the remaining space due to the different drive format. Blowing away the ETI partition (and all other partitions) allowed me to continue the Windows install. *REMEMBER – No warranty is provided or implied, just telling you what I did and how I got it to work. Ok, so now Windows is installed and I’m rebooting. Everything looks good, but I need drivers! So I put in the OSX install DVD and run the BootCamp assistant which installs all the Windows drivers I need. Fantastic! Oh, I need to restart – no problem. OH NO, PROBLEM! I left the OSX install DVD in the drive and now the MBP wants to boot from the drive and install OSX! I’m not holding down the C key, what the heck?! Ok, well there must be a way to eject this disk…hmm…no physical button on the side…the eject button doesn’t seem to work on the keyboard…no little pin hole to insert something to force the disc out…well what the…?! It turns out, if you want to eject a disc at boot up, you need (and I kid you not) to plug a mouse into the laptop and hold down the right-click button while its booting. This ejected the disc for me. Seriously. Finally, Things You Should Be Aware Of Once you have Windows up and running there’s a few things you need to be aware of, mainly new keyboard shortcuts. For instance, on the Mac keyboard there is no Home, End, PageUp or PageDown. There’s also no obvious way to do something like select large amounts of text (like you would by holding Shift-Home at the end of a line of text for instance). So here’s some shortcuts you need to know: Home – fn + left arrow End – fn + right arrow Select a line of text as you would with the Home key – Shift + fn + left arrow Select a line of text as you would with the End key – Shift + fn + right arrow Page Up – fn + up arrow Page Down – fn + down arrow Also, you’ll notice that the awesome Mac track pad doesn’t respond to taps as clicks. No fear, this is just a setting that needs to be altered in the BootCamp control panel (that controls the Mac Hardware-specific settings within Windows, you can access it easily from the system tray icon) One other thing, battery life seems a bit lower than with OSX, but then again I’m also doing more than Twitter or web browsing on this thing now. Conclusion My laptop runs awesome now that I have Windows 7 on there. It’s obviously up to individual taste, but for me I just didn’t see benefits to living in an OSX world when everything I needed lived in Windows. And also, I finally am back to an operating system that doesn’t require me to eject a USB drive before physically removing it! It’s 2012 folks, how has this not been fixed?! D

Read the article
How to Control Screen Layouts in LightSwitch

- by ChrisD

Visual Studio LightSwitch has a bunch of screen templates that you can use to quickly generate screens. They give you good starting points that you can customize further. When you add a new screen to your project you see a set of screen templates that you can choose from. These templates lay out all the related data you choose to put on a screen automatically for you. And don’t under estimate them; they do a great job of laying out controls in a smart way. For instance, a tab control will be used when you select more than one related set of data to display on a screen. However, you’re not limited to taking the layout as is. In fact, the screen designer is pretty flexible and allows you to create stacks of controls in a variety of configurations. You just need to visualize your screen as a series of containers that you can lay out in rows and columns. You then place controls or stacks of controls into these areas to align the screen exactly how you want. If you’re new in Visual Studio LightSwitch, you can see this tutorial. OK, Let’s start with a simple example. I have already designed my data entities for a simple order tracking system similar to the Northwind database. I also have added a Search Data Screen to search my Products already. Now I will add a new Details Screen for my Products and make it the default screen via the “Add New Screen” dialog: The screen designer picks a simple layout for me based on the single entity I chose, in this case Product. Hit F5 to run the application, select a Product on the search screen to open the Product Details Screen. Notice that it’s pretty simple because my entity is simple. Click the “Customize” button in the top right of the screen so we can start tweaking it. The left side of the screen shows the containership of controls and data bindings (called the content tree) and the right side shows the live preview with data. Notice that we have a simple layout of two rows but only one row is populated (with a vertical stack of controls in this case). The bottom row is empty. You can envision the screen like this: Each container will display a group of data that you select. For instance in the above screen, the top row is set to a vertical stack control and the group of data to display is coming from Product. So when laying out screens you need to think in terms of containers of controls bound to groups of data. To change the data to which a container is bound, select the data item next to the container: You can select the “New Group” item in order to create more containers (or controls) within the current container. For instance to totally control the layout, select the Product in the top row and hit the delete key. This will delete the vertical stack and therefore all the controls on the screen. The content tree will still have two rows, but the rows are now both empty. If you want a layout of four containers (two rows and two columns) then select “New Group” for the data item and then change the vertical stack control to “Two Columns” for both of the rows as shown here: You can keep going on and on by selecting new groups and choosing between rows or columns. Here’s a layout with 8 containers, 4 rows and 2 columns: And here is a layout with 7 content areas; one row across the top of the screen and three rows with two columns below that: When you select Choose Content and select a data item like Product it will populate all the controls within the container (row or column in a vertical stack) however you have complete control on what to display within each group. You can delete fields you don’t want to display and/or change their controls. You can also change the size of controls and how they display by changing the settings in the properties window. If you are in the Screen Designer (and not the customization mode like we are here) you can also drag-drop data items from the left-hand side of the screen to the content tree. Note, however, that not all areas of the tree will allow you to drop a data item if there is a binding already set to a different set of data. For instance you can’t drop a Customer ID into the same group as a Product if they originate from different entities. To get around this, all you need to do is create a new group and content area as shown above. Let’s take a more complex example that deals with more than just product. I want to design a complex screen that displays Products and their Category, as well as all the OrderDetails for which that product is selected. This time I will create a new screen and select List and Details, select the Products screen data, and include the related OrderDetails. However I’m going to totally change the layout so that a Product grid is at the top left and below that is the selected Product detail. Below that will be the Category text fields and image in two columns below. On the right side I want the OrderDetails grid to take up the whole right side of the screen. All this can be done in customization mode while you’re debugging the application. To do this, I first deleted all the content items in the tree and then re-created the content tree as shown in the image below. I also set the image to be larger and the description textbox to be 5 rows using the property window below the live preview. I added the green lines to indicate the containers and show how it maps to the content tree (click to enlarge): I hope this demystifies the screen designer a little bit. Remember that screen templates are excellent starting points – you can take them as-is or customize them further. It takes a little fooling around with customizing screens to get them to do exactly what you want but there are a ton of possibilities once you get the hang of it. Stay tuned for more information on how to create your own screen templates that show up in the “Add New Screen” dialog. Enjoy! The tutorial that might be interested: Adding Custom Control In LightSwitch

Read the article
Notes on implementing Visual Studio 2010 Navigate To

- by cyberycon

One of the many neat functions added to Visual Studio in VS 2010 was the Navigate To feature. You can find it by clicking Edit, Navigate To, or by using the keyboard shortcut Ctrl, (yes, that's control plus the comma key). This pops up the Navigate To dialog that looks like this: As you type, Navigate To starts searching through a number of different search providers for your term. The entries in the list change as you type, with most providers doing some kind of fuzzy or at least substring matching. If you have C#, C++ or Visual Basic projects in your solution, all symbols defined in those projects are searched. There's also a file search provider, which displays all matching filenames from projects in the current solution as well. And, if you have a Visual Studio package of your own, you can implement a provider too. Micro Focus (where I work) provide the Visual COBOL language inside Visual Studio (http://visualstudiogallery.msdn.microsoft.com/ef9bc810-c133-4581-9429-b01420a9ea40 ), and we wanted to provide this functionality too. This post provides some notes on the things I discovered mainly through trial and error, but also with some kind help from devs inside Microsoft. The expectation of Navigate To is that it searches across the whole solution, not just the current project. So in our case, we wanted to search for all COBOL symbols inside all of our Visual COBOL projects inside the solution. So first of all, here's the Microsoft documentation on Navigate To: http://msdn.microsoft.com/en-us/library/ee844862.aspx . It's the reference information on the Microsoft.VisualStudio.Language.NavigateTo.Interfaces Namespace, and it lists all the interfaces you will need to implement to create your own Navigate To provider. Navigate To uses Visual Studio's latest mechanism for integrating external functionality and services, Managed Extensibility Framework (MEF). MEF components don't require any registration with COM or any other registry entries to be found by Visual Studio. Visual Studio looks in several well-known locations for manifest files (extension.vsixmanifest). It then uses reflection to scan for MEF attributes on classes in the assembly to determine which functionality the assembly provides. MEF itself is actually part of the .NET framework, and you can learn more about it here: http://mef.codeplex.com/. To get started with Visual Studio and MEF you could do worse than look at some of the editor examples on the VSX page http://archive.msdn.microsoft.com/vsx . I've also written a small application to help with switching between development and production MEF assemblies, which you can find on Codeproject: http://www.codeproject.com/KB/miscctrl/MEF_Switch.aspx. The Navigate To interfaces Back to Navigate To, and summarizing the MSDN reference documentation, you need to implement the following interfaces: INavigateToItemProviderFactoryThis is Visual Studio's entry point to your Navigate To implementation, and you must decorate your implementation with the following MEF export attribute: [Export(typeof(INavigateToItemProviderFactory))] INavigateToItemProvider Your INavigateToItemProviderFactory needs to return your implementation of INavigateToItemProvider. This class implements StartSearch() and StopSearch(). StartSearch() is the guts of your provider, and we'll come back to it in a minute. This object also needs to implement IDisposeable(). INavigateToItemDisplayFactory Your INavigateToItemProvider hands back NavigateToItems to the NavigateTo framework. But to give you good control over what appears in the NavigateTo dialog box, these items will be handed back to your INavigateToItemDisplayFactory, which must create objects implementing INavigateToItemDisplay INavigateToItemDisplay Each of these objects represents one result in the Navigate To dialog box. As well as providing the description and name of the item, this object also has a NavigateTo() method that should be capable of displaying the item in an editor when invoked. Carrying out the search The lifecycle of your INavigateToItemProvider is the same as that of the Navigate To dialog. This dialog is modal, which makes your implementation a little easier because you know that the user can't be changing things in editors and the IDE while this dialog is up. But the Navigate To dialog DOES NOT run on the main UI thread of the IDE – so you need to be aware of that if you want to interact with editors or other parts of the IDE UI. When the user invokes the Navigate To dialog, your INavigateToItemProvider gets sent a TryCreateNavigateToItemProvider() message. Instantiate your INavigateToItemProvider and hand this back. The sequence diagram below shows what happens next. Your INavigateToItemProvider will get called with StartSearch(), and passed an INavigateToCallback. StartSearch() is an asynchronous request – you must return from this method as soon as possible, and conduct your search on a separate thread. For each match to the search term, instantiate a NavigateToItem object and send it to INavigateToCallback.AddItem(). But as the user types in the Search Terms field, NavigateTo will invoke your StartSearch() method repeatedly with the changing search term. When you receive the next StartSearch() message, you have to abandon your current search, and start a new one. You can't rely on receiving a StopSearch() message every time. Finally, when the Navigate To dialog box is closed by the user, you will get a Dispose() message – that's your cue to abandon any uncompleted searches, and dispose any resources you might be using as part of your search. While you conduct your search invoke INavigateToCallback.ReportProgress() occasionally to provide feedback about how close you are to completing the search. There does not appear to be any particular requirement to how often you invoke ReportProgress(), and you report your progress as the ratio of two integers. In my implementation I report progress in terms of the number of symbols I've searched over the total number of symbols in my dictionary, and send a progress report every 16 symbols. Displaying the Results The Navigate to framework invokes INavigateToItemDisplayProvider.CreateItemDisplay() once for each result you passed to the INavigateToCallback. CreateItemDisplay() is passed the NavigateToItem you handed to the callback, and must return an INavigateToItemDisplay object. NavigateToItem is a sealed class which has a few properties, including the name of the symbol. It also has a Tag property, of type object. This enables you to stash away all the information you will need to create your INavigateToItemDisplay, which must implement an INavigateTo() method to display a symbol in an editor IDE when the user double-clicks an entry in the Navigate To dialog box. Since the tag is of type object, it is up to you, the implementor, to decide what kind of object you store in here, and how it enables the retrieval of other information which is not included in the NavigateToItem properties. Some of the INavigateToItemDisplay properties are self-explanatory, but a couple of them are less obvious: Additional informationThe string you return here is displayed inside brackets on the same line as the Name property. In English locales, Visual Studio includes the preposition "of". If you look at the first line in the Navigate To screenshot at the top of this article, Book_WebRole.Default is the additional information for textBookAuthor, and is the namespace qualified type name the symbol appears in. For procedural COBOL code we display the Program Id as the additional information DescriptionItemsYou can use this property to return any textual description you want about the item currently selected. You return a collection of DescriptionItem objects, each of which has a category and description collection of DescriptionRun objects. A DescriptionRun enables you to specify some text, and optional formatting, so you have some control over the appearance of the displayed text. The DescriptionItems property is displayed at the bottom of the Navigate To dialog box, with the Categories on the left and the Descriptions on the right. The Visual COBOL implementation uses it to display more information about the location of an item, making it easier for the user to know disambiguate duplicate names (something there can be a lot of in large COBOL applications). Summary I hope this article is useful for anyone implementing Navigate To. It is a fantastic navigation feature that Microsoft have added to Visual Studio, but at the moment there still don't seem to be any examples on how to implement it, and the reference information on MSDN is a little brief for anyone attempting an implementation.

Read the article
How do I make a jumping dolphin rotate realistically?

- by Johnny

I want to program a dolphin that jumps and rotates like a real dolphin. Jumping is not the problem, but I don't know how to make the rotation. At the moment, my dolphin rotates a little weird. But I want that it rotates like a real dolphin does. How can I improve the rotation? public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; SpriteBatch spriteBatch; Texture2D image, water; float Gravity = 5.0F; float Acceleration = 20.0F; Vector2 Position = new Vector2(1200,720); Vector2 Velocity; float rotation = 0; SpriteEffects flip; Vector2 Speed = new Vector2(0, 0); public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; graphics.PreferredBackBufferWidth = 1280; graphics.PreferredBackBufferHeight = 720; } protected override void Initialize() { base.Initialize(); } protected override void LoadContent() { spriteBatch = new SpriteBatch(GraphicsDevice); image = Content.Load<Texture2D>("cartoondolphin"); water = Content.Load<Texture2D>("background"); flip = SpriteEffects.None; } protected override void Update(GameTime gameTime) { float VelocityX = 0f; float VelocityY = 0f; float time = (float)gameTime.ElapsedGameTime.TotalSeconds; KeyboardState kbState = Keyboard.GetState(); if(kbState.IsKeyDown(Keys.Left)) { rotation = 0; flip = SpriteEffects.None; VelocityX += -5f; } if(kbState.IsKeyDown(Keys.Right)) { rotation = 0; flip = SpriteEffects.FlipHorizontally; VelocityX += 5f; } // jump if the dolphin is under water if(Position.Y >= 670) { if (kbState.IsKeyDown(Keys.A)) { if (flip == SpriteEffects.None) { rotation += 0.01f; VelocityY += 40f; } else { rotation -= 0.01f; VelocityY += 40f; } } } else { if (flip == SpriteEffects.None) { rotation -= 0.01f; VelocityY += -10f; } else { rotation += 0.01f; VelocityY += -10f; } } float deltaY = 0; float deltaX = 0; deltaY = Gravity * (float)gameTime.ElapsedGameTime.TotalSeconds; deltaX += VelocityX * (float)gameTime.ElapsedGameTime.TotalSeconds * Acceleration; deltaY += -VelocityY * (float)gameTime.ElapsedGameTime.TotalSeconds * Acceleration; Speed = new Vector2(Speed.X + deltaX, Speed.Y + deltaY); Position += Speed * (float)gameTime.ElapsedGameTime.TotalSeconds; Velocity.X = 0; if (Position.Y + image.Height/2 > graphics.PreferredBackBufferHeight) Position.Y = graphics.PreferredBackBufferHeight - image.Height/2; base.Update(gameTime); } protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); spriteBatch.Begin(); spriteBatch.Draw(water, new Rectangle(0, graphics.PreferredBackBufferHeight -100, graphics.PreferredBackBufferWidth, 100), Color.White); spriteBatch.Draw(image, Position, null, Color.White, rotation, new Vector2(image.Width / 2, image.Height / 2), 1, flip, 1); spriteBatch.End(); base.Draw(gameTime); } } I changed my code a little. But I still have some trouble with the rotation. Here's the entire code. The dolphin looks at the wrong direction if I press the left or right key. For example, it looks down if I press the left key. What is wrong with the rotation? At the beginning, the dolphin looks at the left side, but after I pressed a key it just looks down or up. I deleted the "rotation += 0.01f;" lines in the code. Is that correct? public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; SpriteBatch spriteBatch; Texture2D image, water; float Gravity = 5.0F; float Acceleration = 20.0F; Vector2 Position = new Vector2(1200,720); Vector2 Velocity; float rotation = 0; SpriteEffects flip; Vector2 Speed = new Vector2(0, 0); Vector2 prevPos; public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; graphics.PreferredBackBufferWidth = 1280; graphics.PreferredBackBufferHeight = 720; } protected override void Initialize() { base.Initialize(); } protected override void LoadContent() { spriteBatch = new SpriteBatch(GraphicsDevice); image = Content.Load<Texture2D>("cartoondolphin"); water = Content.Load<Texture2D>("background"); flip = SpriteEffects.None; } protected override void Update(GameTime gameTime) { float VelocityX = 0f; float VelocityY = 0f; float time = (float)gameTime.ElapsedGameTime.TotalSeconds; KeyboardState kbState = Keyboard.GetState(); if(kbState.IsKeyDown(Keys.Left)) { flip = SpriteEffects.None; VelocityX += -5f; } if(kbState.IsKeyDown(Keys.Right)) { flip = SpriteEffects.FlipHorizontally; VelocityX += 5f; } rotation = (float)Math.Atan2(Position.X - prevPos.X, Position.Y - prevPos.Y); prevPos = Position; // jump if the dolphin is under water if(Position.Y >= 670) { if (kbState.IsKeyDown(Keys.A)) { if (flip == SpriteEffects.None) { VelocityY += 40f; } else { VelocityY += 40f; } } } else { if (flip == SpriteEffects.None) { VelocityY += -10f; } else { VelocityY += -10f; } } float deltaY = 0; float deltaX = 0; deltaY = Gravity * (float)gameTime.ElapsedGameTime.TotalSeconds; deltaX += VelocityX * (float)gameTime.ElapsedGameTime.TotalSeconds * Acceleration; deltaY += -VelocityY * (float)gameTime.ElapsedGameTime.TotalSeconds * Acceleration; Speed = new Vector2(Speed.X + deltaX, Speed.Y + deltaY); Position += Speed * (float)gameTime.ElapsedGameTime.TotalSeconds; Velocity.X = 0; if (Position.Y + image.Height/2 > graphics.PreferredBackBufferHeight) Position.Y = graphics.PreferredBackBufferHeight - image.Height/2; base.Update(gameTime); } protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue); spriteBatch.Begin(); spriteBatch.Draw(water, new Rectangle(0, graphics.PreferredBackBufferHeight -100, graphics.PreferredBackBufferWidth, 100), Color.White); spriteBatch.Draw(image, Position, null, Color.White, rotation, new Vector2(image.Width / 2, image.Height / 2), 1, flip, 1); spriteBatch.End(); base.Draw(gameTime); } }

Read the article

Search Results

Search found 12824 results on 513 pages for 'glen little'.

Page 162/513 | < Previous Page | 158 159 160 161 162 163 164 165 166 167 168 169 | Next Page >

- by zowens

- by James Michael Hare

- by Most Valuable Yak (Rob Volk)

- by Rick Strahl

- by mbridge

- by Most Valuable Yak (Rob Volk)

- by Reed

- by Mladen Prajdic

- by Jeff

- by Argenis

- by Timothy Klenke

- by PSteele

- by Dave

- by raysmithequip

- by Renso

- by TStewartDev

- by Mike Dietrich

- by Jason Fitzpatrick

- by D'Arcy Lussier

- by ChrisD

- by cyberycon

- by Johnny

< Previous Page | 158 159 160 161 162 163 164 165 166 167 168 169 | Next Page >