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Microsoft BUILD 2013 Day 1–Keynote

- by Tim Murphy

Originally posted on: http://geekswithblogs.net/tmurphy/archive/2013/06/27/microsoft-build-2013-day-1ndashkeynote.aspx This one is going to be a little long because the keynote was jam-packed so bare with me. The keynote for the first day of BUILD 2013 was kicked off by Steve Balmer. He made it very clear that Microsoft’s focus is on accelerating its time to market with products and product updates. His quote was that “Rapid release” is the new norm. He continued by showing off several new Lumias that have been buzzing around the internet for a while and announce that Sprint will now be carrying the HTC 8XT and Samsung ATIV. Balmer is known for repeating words or phrase for affect. This time it was “Rapid release, rapid release” and “Touch, touch, touch, touch, touch, …”. This was fun, but even more fun was when he announce that all attendees would receive an Acer Iconia 8” tablet. SCORE! The next subject Balmer focused on is new apps. The three new ones were Flipboard, Facebook and NFL Fantasy Football. I liked the first two because these are ones that people coming from other platforms are missing. The NFL app is great just because it targets a demographic that can be fanatical. If these types of apps keep coming than the missing app argument goes away. While many Negative Nancy’s are describing Windows 8.1 as Windows 180 Steve Balmer chose to call it a “refined blend” as in a coffee that has been improved with a new mix. This includes more multi-tasking options and leveraging Bing straight throughout the entire ecosystem. He ended this first section by explaining that this will also bring more Bing development opportunities to the community. Steve Balmer was followed by Julie Larson-Green who spent her time on stage selling us on Windows 8 all over again from my point of view. Something that I would not have thought was needed until I had listened to some other attendees who had a number of concerns and complaints. She showed a number of new gestures that will come with Windows 8.1, and while they were cool I was left wondering if they really improved the experience. I guess only time will tell. I did like the fact that it the UI implementation to bring up “All Apps” now mirrors that of Windows Phone. The consistency is a big step forward that I hope to see continue. The cool factor went up from there as she swiped content from a desktop (mega-tablet) to the XBox One. This seamless experience I believe is what is really needed for any future platform to be relevant. I was much more enthused by the presentation of Antoine Leblond who humbled us by letting us know that there are 5k new API. How that can be or how anyone would ever use all of them is another question. His announcement was that the Visual Studio 2013 preview would be available today along with the Windows 8.1 bits. One of the features of VS2013 that he demonstrated is the power consumption profiler. With battery life being a key factor with consumer consumption devices this is a welcome addition. He didn’t limit his presentation to VS2013 features though. He showed how the Store has been redesigned to enable better search and discoverability of apps and how Win 8.1 can perform multiple screen scales depending on the resolution of the device automatically. The last feature he demoed was the real time video streaming API which he made sure we understood by attaching a Surface to a little robot. Oh, but there was one more thing. Antoine and Julie announce that all attendees would also be getting Surface Pros. BONUS! How much more could there be? Gurdeep Singh Pall was about to pile on. He introduced us to Bing as a platform (BaaP?). He said if they (Microsoft) could do something with and API that is good 3rd party developers can do something that is dynamite and showed us some of the tools they had produced. These included natural user interface improvements such as voice commands that looked to put Siri to shame. Add to that 3D, OCR and translation capabilities and the future looks to be full of opportunities. Balmer then came out to show us one last thing. Project Spark is a game design environment that will be available for Windows 8.1, XBox 360 and XBox One. All I can say is that if my kids get their hands on this they are going to be able to learn some of what dad does in a much more enjoyable way. At the end of it all I was both exhausted and energized by what I saw. What could they have possibly left for the day 2 keynote? I hear it will feature Scott Hanselman. If that is right we are in for a treat. See you there. del.icio.us Tags: BUILD 2013,Windows 8.1,Winodws Phone,XAML,Keynote,Bing,Visual Studio 2013,Project Spark

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NetBeans, JSF, and MySQL Primary Keys using AUTO_INCREMENT

- by MarkH

I recently had the opportunity to spin up a small web application using JSF and MySQL. Having developed JSF apps with Oracle Database back-ends before and possessing some small familiarity with MySQL (sans JSF), I thought this would be a cakewalk. Things did go pretty smoothly...but there was one little "gotcha" that took more time than the few seconds it really warranted. The Problem Every DBMS has its own way of automatically generating primary keys, and each has its pros and cons. For the Oracle Database, you use a sequence and point your Java classes to it using annotations that look something like this: @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="POC_ID_SEQ") @SequenceGenerator(name="POC_ID_SEQ", sequenceName="POC_ID_SEQ", allocationSize=1) Between creating the actual sequence in the database and making sure you have your annotations right (watch those typos!), it seems a bit cumbersome. But it typically "just works", without fuss. Enter MySQL. Designating an integer-based field as PRIMARY KEY and using the keyword AUTO_INCREMENT makes the same task seem much simpler. And it is, mostly. But while NetBeans cranks out a superb "first cut" for a basic JSF CRUD app, there are a couple of small things you'll need to bring to the mix in order to be able to actually (C)reate records. The (RUD) performs fine out of the gate. The Solution Omitting all design considerations and activity (!), here is the basic sequence of events I followed to create, then resolve, the JSF/MySQL "Primary Key Perfect Storm": Fire up NetBeans. Create JSF project. Create Entity Classes from Database. Create JSF Pages from Entity Classes. Test run. Try to create record and hit error. It's a simple fix, but one that was fun to find in its completeness. :-) Even though you've told it what to do for a primary key, a MySQL table requires a gentle nudge to actually generate that new key value. Two things are needed to make the magic happen. First, you need to ensure the following annotation is in place in your Java entity classes: @GeneratedValue(strategy = GenerationType.IDENTITY) All well and good, but the real key is this: in your controller class(es), you'll have a create() function that looks something like this, minus the comment line and the setId() call in bold red type: public String create() { try { // Assign 0 to ID for MySQL to properly auto_increment the primary key. current.setId(0); getFacade().create(current); JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("CategoryCreated")); return prepareCreate(); } catch (Exception e) { JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured")); return null; } } Setting the current object's primary key attribute to zero (0) prior to saving it tells MySQL to get the next available value and assign it to that record's key field. Short and simple…but not inherently obvious if you've never used that particular combination of NetBeans/JSF/MySQL before. Hope this helps! All the best, Mark

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How to properly add texture to multi-fixture/shape b2Body

- by Blazej Wdowikowski

Hello to everyone this is my first poste here I hope that will be not fail start. At start I must say I make part 1 in Ray's Tutorial "How To Make A Game Like Fruit Ninja With Box2D and Cocos2D". But I wonder what when I want make more complex body with texture? Simple just add n b2FixtureDef to the same body. OK but what about texture? If I will take code from that tutorial it only fill last fixture. Probably it does not takes every b2Vec2 point. I was right, it did not. So quick refactor and from that -(id)initWithTexture:(CCTexture2D*)texture body:(b2Body*)body original:(BOOL)original { // gather all the vertices from our Box2D shape b2Fixture *originalFixture = body->GetFixtureList(); b2PolygonShape *shape = (b2PolygonShape*)originalFixture->GetShape(); int vertexCount = shape->GetVertexCount(); NSMutableArray *points = [NSMutableArray arrayWithCapacity:vertexCount]; for(int i = 0; i < vertexCount; i++) { CGPoint p = ccp(shape->GetVertex(i).x * PTM_RATIO, shape->GetVertex(i).y * PTM_RATIO); [points addObject:[NSValue valueWithCGPoint:p]]; } if ((self = [super initWithPoints:points andTexture:texture])) { _body = body; _body->SetUserData(self); _original = original; // gets the center of the polygon _centroid = self.body->GetLocalCenter(); // assign an anchor point based on the center self.anchorPoint = ccp(_centroid.x * PTM_RATIO / texture.contentSize.width, _centroid.y * PTM_RATIO / texture.contentSize.height); } return self; } I came up with that -(id)initWithTexture:(CCTexture2D*)texture body:(b2Body*)body original:(BOOL)original { int vertexCount = 0; //gather total number of b2Vect2 points b2Fixture *currentFixture = body->GetFixtureList(); while (currentFixture) { //new b2PolygonShape *shape = (b2PolygonShape*)currentFixture->GetShape(); vertexCount += shape->GetVertexCount(); currentFixture = currentFixture->GetNext(); } NSMutableArray *points = [NSMutableArray arrayWithCapacity:vertexCount]; // gather all the vertices from our Box2D shape b2Fixture *originalFixture = body->GetFixtureList(); while (originalFixture) { //new NSLog((NSString*)@"-"); b2PolygonShape *shape = (b2PolygonShape*)originalFixture->GetShape(); int currentVertexCount = shape->GetVertexCount(); for(int i = 0; i < currentVertexCount; i++) { CGPoint p = ccp(shape->GetVertex(i).x * PTM_RATIO, shape->GetVertex(i).y * PTM_RATIO); [points addObject:[NSValue valueWithCGPoint:p]]; } originalFixture = originalFixture->GetNext(); } if ((self = [super initWithPoints:points andTexture:texture])) { _body = body; _body->SetUserData(self); _original = original; // gets the center of the polygon _centroid = self.body->GetLocalCenter(); // assign an anchor point based on the center self.anchorPoint = ccp(_centroid.x * PTM_RATIO / texture.contentSize.width,_centroid.y * PTM_RATIO / texture.contentSize.height); } return self; } I was working for simple two fixtures body like b2BodyDef bodyDef; bodyDef.type = b2_dynamicBody; bodyDef.position = position; bodyDef.angle = rotation; b2Body *body = world->CreateBody(&bodyDef); b2FixtureDef fixtureDef; fixtureDef.density = 1.0; fixtureDef.friction = 0.5; fixtureDef.restitution = 0.2; fixtureDef.filter.categoryBits = 0x0001; fixtureDef.filter.maskBits = 0x0001; b2Vec2 vertices[] = { b2Vec2(0.0/PTM_RATIO,50.0/PTM_RATIO), b2Vec2(0.0/PTM_RATIO,0.0/PTM_RATIO), b2Vec2(50.0/PTM_RATIO,30.1/PTM_RATIO), b2Vec2(60.0/PTM_RATIO,60.0/PTM_RATIO) }; b2PolygonShape shape; shape.Set(vertices, 4); fixtureDef.shape = &shape; body->CreateFixture(&fixtureDef); b2Vec2 vertices2[] = { b2Vec2(20.0/PTM_RATIO,50.0/PTM_RATIO), b2Vec2(20.0/PTM_RATIO,0.0/PTM_RATIO), b2Vec2(70.0/PTM_RATIO,30.1/PTM_RATIO), b2Vec2(80.0/PTM_RATIO,60.0/PTM_RATIO) }; shape.Set(vertices2, 4); fixtureDef.shape = &shape; body->CreateFixture(&fixtureDef); But if I try put secondary shape upper than first it starting wierd, texture goes crazy. For example not mention about more complex shapes. What's more if shapes have one common point texture will not render for them at all [For that I use Physics Edytor like in tutorial part1] BTW. I use PolygonSprite and in method createWithWorld... another shapes. Uff.. Question So my question is, why texture coords are in such a mess up? It's my modify method or just wrong approach? Maybe I should remove duplicated from points array?

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useFastClick in JQuery Mobile

- by Yousef_Jadallah

Normal 0 false false false EN-US X-NONE AR-SA /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} For who want to convert the application from JQM Alpha to JQM Beta 1, needs to bind click events to the new vclick one. Click event is working in general browsers butt that is needed for iOS and Android, useFastClick is (touch + mouse click). Moreover if you have this event alot in your project you can turn useFastClick off in mobileinit event: $(document).bind("mobileinit", function () { $.mobile.useFastClick = false; }); vclick event is needed to support touch events to make the page changes to happen faster, and to perform the URL hiding. So you need to change something like this $('btnShow').live("click", function (evt) { To : $('btnShow').live("vclick", function (evt) { For more information : http://jquerymobile.com/test/docs/api/globalconfig.html Here you can find full example in this case : <!DOCTYPE ><html xmlns="http://www.w3.org/1999/xhtml"><head> <link rel="stylesheet" href="http://code.jquery.com/mobile/1.0b1/jquery.mobile-1.0b1.min.css" /> <script src="http://code.jquery.com/jquery-1.6.1.min.js"></script> <script src="http://code.jquery.com/mobile/1.0b1/jquery.mobile-1.0b1.min.js"></script> <script type="text/javascript"> //Here you need to use vclick instead of click event $('ul[id="MylistView"] a').live("vclick", function (evt) { alert('list click'); }); </script> <title></title></head><body> <div id="FirstPage" data-role="page" data-theme="b"> <div data-role="header"> <h1> Page Title</h1> </div> <div data-role="content"> <ul id="MylistView" data-role="listview" data-theme="g"> <li><a href="#SecondPage">Acura</a></li> <li><a href="#SecondPage">Audi</a></li> <li><a href="#SecondPage">BMW</a></li> </ul> </div> <div data-role="footer"> <h4> Page Footer</h4> </div> </div> <div id="SecondPage" data-role="page" data-theme="b" > <div data-role="header" > <h1> Page Title</h1> </div> Second Page <div data-role="footer"> <h4> Page Footer</h4> </div> </div></body></html> Hope that helps.

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Visual Tree Enumeration

- by codingbloke

I feel compelled to post this blog because I find I’m repeatedly posting this same code in silverlight and windows-phone-7 answers in Stackoverflow. One common task that we feel we need to do is burrow into the visual tree in a Silverlight or Windows Phone 7 application (actually more recently I found myself doing this in WPF as well). This allows access to details that aren’t exposed directly by some controls. A good example of this sort of requirement is found in the “Restoring exact scroll position of a listbox in Windows Phone 7” question on stackoverflow. This required that the scroll position of the scroll viewer internal to a listbox be accessed. A caveat One caveat here is that we should seriously challenge the need for this burrowing since it may indicate that there is a design problem. Burrowing into the visual tree or indeed burrowing out to containing ancestors could represent significant coupling between module boundaries and that generally isn’t a good idea. Why isn’t this idea just not cast aside as a no-no? Well the whole concept of a “Templated Control”, which are in extensive use in these applications, opens the coupling between the content of the visual tree and the internal code of a control. For example, I can completely change the appearance and positioning of elements that make up a ComboBox. The ComboBox control relies on specific template parts having set names of a specified type being present in my template. Rightly or wrongly this does kind of give license to writing code that has similar coupling. Hasn’t this been done already? Yes it has. There are number of blogs already out there with similar solutions. In fact if you are using Silverlight toolkit the VisualTreeExtensions class already provides this feature. However I prefer my specific code because of the simplicity principle I hold to. Only write the minimum code necessary to give all the features needed. In this case I add just two extension methods Ancestors and Descendents, note I don’t bother with “Get” or “Visual” prefixes. Also I haven’t added Parent or Children methods nor additional “AndSelf” methods because all but Children is achievable with the addition of some other Linq methods. I decided to give Descendents an additional overload for depth hence a depth of 1 is equivalent to Children but this overload is a little more flexible than simply Children. So here is the code:- VisualTreeEnumeration public static class VisualTreeEnumeration { public static IEnumerable<DependencyObject> Descendents(this DependencyObject root, int depth) { int count = VisualTreeHelper.GetChildrenCount(root); for (int i = 0; i < count; i++) { var child = VisualTreeHelper.GetChild(root, i); yield return child; if (depth > 0) { foreach (var descendent in Descendents(child, --depth)) yield return descendent; } } } public static IEnumerable<DependencyObject> Descendents(this DependencyObject root) { return Descendents(root, Int32.MaxValue); } public static IEnumerable<DependencyObject> Ancestors(this DependencyObject root) { DependencyObject current = VisualTreeHelper.GetParent(root); while (current != null) { yield return current; current = VisualTreeHelper.GetParent(current); } } } Usage examples The following are some examples of how to combine the above extension methods with Linq to generate the other axis scenarios that tree traversal code might require. Missing Axis Scenarios var parent = control.Ancestors().Take(1).FirstOrDefault(); var children = control.Descendents(1); var previousSiblings = control.Ancestors().Take(1) .SelectMany(p => p.Descendents(1).TakeWhile(c => c != control)); var followingSiblings = control.Ancestors().Take(1) .SelectMany(p => p.Descendents(1).SkipWhile(c => c != control).Skip(1)); var ancestorsAndSelf = Enumerable.Repeat((DependencyObject)control, 1) .Concat(control.Ancestors()); var descendentsAndSelf = Enumerable.Repeat((DependencyObject)control, 1) .Concat(control.Descendents()); You might ask why I don’t just include these in the VisualTreeEnumerator. I don’t on the principle of only including code that is actually needed. If you find that one or more of the above is needed in your code then go ahead and create additional methods. One of the downsides to Extension methods is that they can make finding the method you actually want in intellisense harder. Here are some real world usage scenarios for these methods:- Real World Scenarios //Gets the internal scrollviewer of a ListBox ScrollViewer sv = someListBox.Descendents().OfType<ScrollViewer>().FirstOrDefault(); // Get all text boxes in current UserControl:- var textBoxes = this.Descendents().OfType<TextBox>(); // All UIElement direct children of the layout root grid:- var topLevelElements = LayoutRoot.Descendents(0).OfType<UIElement>(); // Find the containing `ListBoxItem` for a UIElement:- var container = elem.Ancestors().OfType<ListBoxItem>().FirstOrDefault(); // Seek a button with the name "PinkElephants" even if outside of the current Namescope:- var pinkElephantsButton = this.Descendents() .OfType<Button>() .FirstOrDefault(b => b.Name == "PinkElephants"); //Clear all checkboxes with the name "Selector" in a Treeview foreach (CheckBox checkBox in elem.Descendents() .OfType<CheckBox>().Where(c => c.Name == "Selector")) { checkBox.IsChecked = false; } The last couple of examples above demonstrate a common requirement of finding controls that have a specific name. FindName will often not find these controls because they exist in a different namescope. Hope you find this useful, if not I’m just glad to be able to link to this blog in future stackoverflow answers.

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Managing Your First SharePoint Project or Team

- by Mark Rackley

(*editor’s note* If you have proper SharePoint Training, know the difference between a site and a site collection, and have the utmost respect for the knowledge of your SharePoint team skip this blog and go directly to meetdux.com, do not pass go, do not collect $200… otherwise, please proceed) Dear Mr. or Mrs. I-know-nothing-about-SharePoint-but-hey,-I-have-manager-in-my-title-so-I’ll-tell-you-how-to-your-job, Thank you so much for joining the Acme corporation. We appreciate your eagerness and willingness to jump in and help us accomplish all of our goals here at acme (these roadrunner rockets don’t make themselves). You may have noticed that we have this thing called SharePoint lying around and we have invested some time in money to make it not a complete piece of garbage. So, I thought I’d give you some pointers to help make your stay here enjoyable and productive. Yeah… you don’t really know SharePoint Just because you had a mysite at your last organization or had a SharePoint 2003 team site does NOT mean you comprehend the vastness that is SharePoint. You don’t know what’s going on behind the scenes. You don’t know what should and should not be done. No, we CAN’T just query the SQL database directly. Yes, it really does take that long. No, we can’t do that out-of-the-box. Your experience doesn’t mean as much as you think it means… Yes, I’m aware that you co-created the internet with Al Gore and have been managing projects since I was blowing up GI Joe figures with firecrackers, however SharePoint is not like anything you have worked with before from a management perspective. Please don’t tell us the proper way to do our job or tell us how “you” would do it, and PLEASE don’t utter the words “I used to do some .NET development so let me know if you get stuck and need some guidance.” It MAY be possible for a incredible project manager to manage a SharePoint project and not understand the technology, but if you force your ideas on us or treat us like we don’t really know what we’re doing then you will prove yourself to NOT be one of those types. Oh no you didn’t… Please don’t tell us how you can bring in a group of guys of Kazakhstan to do the project for $20/hr. There are many companies out there who can do some really crappy SharePoint work and we don’t want to be stuck maintaining their junk. Do you know what it means to deploy a solution? Neither do some of those companies out there. However, there are are few AWESOME consulting firms out there but $150/hr is cheap for these guys. Believe me, it’s worth it though. You get what you pay for! Show us some respect We truly do appreciate and value your opinion and experience, but when we tell you something is different in SharePoint don’t be condescending and dismiss OUR experience and opinions. We have spent a lot of time and energy learning a very complicated technology that can open up a world of possibilities when used properly. We just want to make sure it is used properly. It’s not the same as .NET development. It’s not like a regular web application. There’s more going on behind the scenes than you can possibly fathom. Have a little faith in us please and listen when we talk. You may actually learn a thing or two. Take some time to learn the technology There is hope… you don’t have to be totally worthless. Take some time to learn SharePoint. Learn what it is and what it can do. Invest some time in learning our SharePoint environment. What’s our logical architecture and taxonomy? What governance do we have in place? If you just thought “huh?” then yes, I’m talking to you. Sincerely, Your SharePoint Team (This rant is not pointed at any particular organization or person. If you think it’s about you, you are wrong. This is just a general rant based upon things people have told me and things I’ve seen. If you don’t think it applies to you, please move on. If you think you might be guilty of handling your SharePoint team the wrong way, then just please listen, learn, and have a little faith in your team. You all have the same goal in mind. Also, take the time to learn something about SharePoint, you will all be less frustrated with each other.)

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Part 8: How to name EBS Customizations

- by volker.eckardt(at)oracle.com

You might wonder why I am discussing this here. The reason is simple: nearly every project has a bit different naming conventions, which makes a the life always a bit complicated (for developers, but also setup responsible, and also for consultants). Although we always create a document to describe the technical object naming conventions, I have rarely seen a dedicated document with functional naming conventions. To be precisely, from my stand point, there should always be one global naming definition for an implementation! Let me discuss some related questions: What is the best convention for the customization reference? How to name database objects (tables, packages etc.)? How to name functional objects like Value Sets, Concurrent Programs, etc. How to separate customizations from standard objects best? What is the best convention for the customization reference? The customization reference is the key you use to reference your customization from other lists, from the project plan etc. Usually it is something like XXHU_CONV_22 (HU=customer abbreviation, CONV=Conversion object #22) or XXFA_DEPRN_RPT_02 (FA=Fixed Assets, DEPRN=Short object group, here depreciation, RPT=Report, 02=2nd report in this area) As this is just a reference (not an object name yet), I would prefer the second option. XX=Customization, FA=Main EBS Module linked (you may have sometimes more, but FA is the main) DEPRN_RPT=Short name to specify the customization 02=a unique number Important here is that the HU isn’t used, because XX is enough to mark a custom object, and the 3rd+4th char can be used by the EBS module short name. How to name database objects (tables, packages etc.)? I was leading different developer teams, and I know that one common way is it to take the Customization reference and add more chars behind to classify the object (like _V for view and _T1 for triggers etc.). The only concern I have with this approach is the reusability. If you name your view XXFA_DEPRN_RPT_02_V, no one will by choice reuse this nice view, as it seams to be specific for this CEMLI. My suggestion is rather to name the view XXFA_DEPRN_PERIODS_V and allow herewith reusability for other CEMLIs (although the view will be deployed primarily with CEMLI package XXFA_DEPRN_RPT_02). (check also one of the following Blogs where I will talk about deployment.) How to name Value Sets, Concurrent Programs, etc. For Value Sets I would go with the same convention as for database objects, starting with XX<Module> …. For Concurrent Programs the situation is a bit different. This “object” is seen and used by a lot of users, and they will search for. In many projects it is common to start again with the company short name, or with XX. My proposal would differ. If you have created your own report and you name it “XX: Invoice Report”, the user has to remember that this report does not start with “I”, it starts with X. Would you like typing an X if you are looking for an Invoice report? No, you wouldn’t! So my advise would be to name it: “Invoice Report (XXAP)”. Still we know it is custom (because of the XXAP), but the end user will type the key “i” to get it (and will see similar reports starting also with “i”). I hope that the general schema behind has now become obvious. How to separate customizations from standard objects best? I would not have this section here if the naming would not play an important role. Unfortunately, we can not always link a custom application to our own object, therefore the naming is really important. In the file system structure we use our $XXyy_TOP, in JAVA_TOP it is perhaps also “xx” in front. But in the database itself? Although there are different concepts in place, still many implementations are using the standard “apps” approach, means custom objects are stored in the apps schema (which should not cause any trouble). Final advise: review the naming conventions regularly, once a month. You may have to add more! And, publish them! To summarize: Technical and functional customized objects should always follow a naming convention. This naming convention should be project wide, and only one place shall be used to maintain (like in a Wiki). If the name is for the end user, rather put a customization identifier at the end; if it is an internal name, start with XX…

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Code refactoring with Visual Studio 2010 Part-4

- by Jalpesh P. Vadgama

I have been writing few post with code refactoring features in Visual Studio 2010. This post also will be part of series and this post will be last of the series. In this post I am going explain two features 1) Encapsulate Field and 2) Extract Interface. Let’s explore both features in details. Encapsulate Field: This is a nice code refactoring feature provides by Visual Studio 2010. With help of this feature we can create properties from the existing private field of the class. Let’s take a simple example of Customer Class. In that I there are two private field called firstName and lastName. Below is the code for the class. public class Customer { private string firstName; private string lastName; public string Address { get; set; } public string City { get; set; } } Now lets encapsulate first field firstName with Encapsulate feature. So first select that field and goto refactor menu in Visual Studio 2010 and click on Encapsulate Field. Once you click that a dialog box will appear like following. Now once you click OK a preview dialog box will open as we have selected preview reference changes. I think its a good options to check that option to preview code that is being changed by IDE itself. Dialog will look like following. Once you click apply it create a new property called FirstName. Same way I have done for the lastName and now my customer class code look like following. public class Customer { private string firstName; public string FirstName { get { return firstName; } set { firstName = value; } } private string lastName; public string LastName { get { return lastName; } set { lastName = value; } } public string Address { get; set; } public string City { get; set; } } So you can see that its very easy to create properties with existing fields and you don’t have to change anything there in code it will change all the stuff itself. Extract Interface: When you are writing software prototype and You don’t know the future implementation of that then its a good practice to use interface there. I am going to explain here that How we can extract interface from the existing code without writing a single line of code with the help of code refactoring feature of Visual Studio 2010. For that I have create a Simple Repository class called CustomerRepository with three methods like following. public class CustomerRespository { public void Add() { // Some code to add customer } public void Update() { //some code to update customer } public void Delete() { //some code delete customer } } In above class there are three method Add,Update and Delete where we are going to implement some code for each one. Now I want to create a interface which I can use for my other entities in project. So let’s create a interface from the above class with the help of Visual Studio 2010. So first select class and goto refactor menu and click Extract Interface. It will open up dialog box like following. Here I have selected all the method for interface and Once I click OK then it will create a new file called ICustomerRespository where it has created a interface. Just like following. Here is a code for that interface. using System; namespace CodeRefractoring { interface ICustomerRespository { void Add(); void Delete(); void Update(); } } Now let's see the code for the our class. It will also changed like following to implement the interface. public class CustomerRespository : ICustomerRespository { public void Add() { // Some code to add customer } public void Update() { //some code to update customer } public void Delete() { //some code delete customer } } Isn't that great we have created a interface and implemented it without writing a single line of code. Hope you liked it. Stay tuned for more.. Till that Happy Programming.

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MERGE gives better OUTPUT options

- by Rob Farley

MERGE is very cool. There are a ton of useful things about it – mostly around the fact that you can implement a ton of change against a table all at once. This is great for data warehousing, handling changes made to relational databases by applications, all kinds of things. One of the more subtle things about MERGE is the power of the OUTPUT clause. Useful for logging. If you’re not familiar with the OUTPUT clause, you really should be – it basically makes your DML (INSERT/DELETE/UPDATE/MERGE) statement return data back to you. This is a great way of returning identity values from INSERT commands (so much better than SCOPE_IDENTITY() or the older (and worse) @@IDENTITY, because you can get lots of rows back). You can even use it to grab default values that are set using non-deterministic functions like NEWID() – things you couldn’t normally get back without running another query (or with a trigger, I guess, but that’s not pretty). That inserted table I referenced – that’s part of the ‘behind-the-scenes’ work that goes on with all DML changes. When you insert data, this internal table called inserted gets populated with rows, and then used to inflict the appropriate inserts on the various structures that store data (HoBTs – the Heaps or B-Trees used to store data as tables and indexes). When deleting, the deleted table gets populated. Updates get a matching row in both tables (although this doesn’t mean that an update is a delete followed by an inserted, it’s just the way it’s handled with these tables). These tables can be referenced by the OUTPUT clause, which can show you the before and after for any DML statement. Useful stuff. MERGE is slightly different though. With MERGE, you get a mix of entries. Your MERGE statement might be doing some INSERTs, some UPDATEs and some DELETEs. One of the most common examples of MERGE is to perform an UPSERT command, where data is updated if it already exists, or inserted if it’s new. And in a single operation too. Here, you can see the usefulness of the deleted and inserted tables, which clearly reflect the type of operation (but then again, MERGE lets you use an extra column called $action to show this). (Don’t worry about the fact that I turned on IDENTITY_INSERT, that’s just so that I could insert the values) One of the things I love about MERGE is that it feels almost cursor-like – the UPDATE bit feels like “WHERE CURRENT OF …”, and the INSERT bit feels like a single-row insert. And it is – but into the inserted and deleted tables. The operations to maintain the HoBTs are still done using the whole set of changes, which is very cool. And $action – very convenient. But as cool as $action is, that’s not the point of my post. If it were, I hope you’d all be disappointed, as you can’t really go near the MERGE statement without learning about it. The subtle thing that I love about MERGE with OUTPUT is that you can hook into more than just inserted and deleted. Did you notice in my earlier query that my source table had a ‘src’ field, that wasn’t used in the insert? Normally, this would be somewhat pointless to include in my source query. But with MERGE, I can put that in the OUTPUT clause. This is useful stuff, particularly when you’re needing to audit the changes. Suppose your query involved consolidating data from a number of sources, but you didn’t need to insert that into the actual table, just into a table for audit. This is now very doable, either using the INTO clause of OUTPUT, or surrounding the whole MERGE statement in brackets (parentheses if you’re American) and using a regular INSERT statement. This is also doable if you’re using MERGE to just do INSERTs. In case you hadn’t realised, you can use MERGE in place of an INSERT statement. It’s just like the UPSERT-style statement we’ve just seen, except that we want nothing to match. That’s easy to do, we just use ON 1=2. This is obviously more convoluted than a straight INSERT. And it’s slightly more effort for the database engine too. But, if you want the extra audit capabilities, the ability to hook into the other source columns is definitely useful. Oh, and before people ask if you can also hook into the target table’s columns... Yes, of course. That’s what deleted and inserted give you.

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SharePoint 2010 Diagnostic Studio Remote Diag

- by juanlarios

I have had some time this week to try out some tools that I have been meaning to try out. This week I am trying out the SP 2010 Diagnostic Studio. I installed it successfully and tried it on my development evironment. I was able to build a report and a snapshot of the environment. I decided to turn my attention to my Employer's intranet environment. This would allow me to analyze it and measure it against benchmarks. I didn't want to install the Diagnostic studio on the Production Envorinment, lucky for me, the Diagnostic studio can be run remotely, well...kind of. Issue My development environment is a stand alone, full installation of SharePoint 2010 Server. It has Office 2010, SQL 2008 Enterprise, a DC...well you get the point, it's jammed packed! But more importantly it's a stand alone, self contained VM environment. Well Microsoft has instructions as to how to connect remotely with Diagnostic Studio here. The deciving part of this is that the SP2010DS prompts you for credentails. So I thought I was getting the right account to run the reports. I tried all the Power Shell commands in the link above but I still ended up getting the following errors: 06/28/2011 12:50:18 Connecting to remote server failed with the following error message : The WinRM client cannot process the request...If the SPN exists, but CredSSP cannot use Kerberos to validate the identity of the target computer and you still want to allow the delegation of the user credentials to the target computer, use gpedit.msc and look at the following policy: Computer Configuration -> Administrative Templates -> System -> Credentials Delegation -> Allow Fresh Credentials with NTLM-only Server Authentication. Verify that it is enabled and configured with an SPN appropriate for the target computer. For example, for a target computer name "myserver.domain.com", the SPN can be one of the following: WSMAN/myserver.domain.com or WSMAN/*.domain.com. Try the request again after these changes. For more information, see the about_Remote_Troubleshooting Help topic. 06/28/2011 12:54:47 Access to the path '\\<targetserver>\C$\Users\<account logging in>\AppData\Local\Temp' is denied. You might also get an error message like this: The WinRM client cannot process the request. A computer policy does not allow the delegation of the user credentials to the target computer. Explanation After looking at the event logs on the target environment, I noticed that there were a several Security Exceptions. After looking at the specifics around who was denied access, I was able to see the account that was being denied access, it was the client machine administrator account. Well of course that was never going to work!!! After some quick Googling, the last error message above will lead you to edit the Local Group Policy on the client server. And although there are instructions from microsoft around doing this, it really will not work in this scenario. Notice the Description and how it only applices to authentication mentioned? Resolution I can tell you what I did, but I wish there was a better way but I simply don't know if it's duable any other way. Because my development environment had it's own DC, I didn't really want to mess with Kerberos authentication. I would also not be smart to connect that server to the domain, considering it has it's own DC. I ended up installing SharePoint 2010 Diagnostic Studio on another Windows 7 Dev environment I have, and connected the machien to the domain. I ran all the necesary remote credentials commands mentioned here. Those commands add the group policy for you! Once I did this I was able to authenticate properly and I was able to get the reports. Conclusion You can run SharePoint 2010 Diagnostic Studio Remotely but it will require some specific scenarions. A couple of things I should mention is that as far as I understand, SP2010 DS, will install agents on your target environment to run tests and retrieve the data. I was a Farm Administrator, and also a Server Admin on SharePoint Server. I am not 100% sure if you need all those permissions but I that's just what I have to my internal intranet. I deally I would like to have a machine that I can have SharePoint 2010 DIagnostic Studio installed and I can run that against client environments. It appears that I will not be able to do that, unless I enable Kerberos on my Windows 7 Machine now. If you have it installed in the same way I would like to have it, please let me know, I'll keep trying to get what I'm after. Hope this helps someone out there doing the same.

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Upgrading to Code Based Migrations EF 4.3.1 with Connector/Net 6.6

- by GABMARTINEZ

Entity Framework 4.3.1 includes a new feature called code first migrations. We are adding support for this feature in our upcoming 6.6 release of Connector/Net. In this walk-through we'll see the workflow of code-based migrations when you have an existing application and you would like to upgrade to this EF 4.3.1 version and use this approach, so you can keep track of the changes that you do to your database. The first thing we need to do is add the new Entity Framework 4.3.1 package to our application. This should via the NuGet package manager. You can read more about why EF is not part of the .NET framework here. Adding EF 4.3.1 to our existing application Inside VS 2010 go to Tools -> Library Package Manager -> Package Manager Console, this will open the Power Shell Host Window where we can work with all the EF commands. In order to install this library to your existing application you should type Install-Package EntityFramework This will make some changes to your application. So Let's check them. In your .config file you'll see a <configSections> which contains the version you have from EntityFramework and also was added the <entityFramework> section as shown below. This section is by default configured to use SQL Express which won't be necesary for this case. So you can comment it out or leave it empty. Also please make sure you're using the Connector/Net 6.6.x version which is the one that has this support as is shown in the previous image. At this point we face one issue; in order to be able to work with Migrations we need the __MigrationHistory table that we don't have yet since our Database was created with an older version. This table is used to keep track of the changes in our model. So we need to get it in our existing Database. Getting a Migration-History table into an existing database First thing we need to do to enable migrations in our existing application is to create our configuration class which will set up the MySqlClient Provider as our SQL Generator. So we have to add it with the following code: using System.Data.Entity.Migrations; //add this at the top of your cs file public class Configuration : DbMigrationsConfiguration<NameOfYourDbContext> //Make sure to use the name of your existing DBContext { public Configuration() { this.AutomaticMigrationsEnabled = false; //Set Automatic migrations to false since we'll be applying the migrations manually for this case. SetSqlGenerator("MySql.Data.MySqlClient", new MySql.Data.Entity.MySqlMigrationSqlGenerator()); } } This code will set up our configuration that we'll be using when executing all the migrations for our application. Once we have done this we can Build our application so we can check that everything is fine. Creating our Initial Migration Now let's add our Initial Migration. In Package Manager Console, execute "add-migration InitialCreate", you can use any other name but I like to set this as our initial create for future reference. After we run this command, some changes were done in our application: A new Migrations Folder was created. A new class migration call InitialCreate which in most of the cases should have empty Up and Down methods as long as your database is up to date with your Model. Since all your entities already exists, delete all duplicated code to create any entity which exists already in your Database if there is any. I found this easier when you don't have any pending updates to do to your database. Now we have our empty migration that will make no changes in our database and represents how are all the things at the begining of our migrations. Finally, let's create our MigrationsHistory table. Optionally you can add SQL code to delete the edmdata table which is not needed anymore. public override void Up() { // Just make sure that you used 4.1 or later version Sql("DROP TABLE EdmMetadata"); } From our Package Manager Console let's type: Update-database; If you like to see the operations made on each Update-database command you can use the flag -verbose after the Update-database. This will make two important changes. It will execute the Up method in the initial migration which has no changes in the database. And second, and very important, it will create the __MigrationHistory table necessary to keep track of your changes. And next time you make a change to your database it will compare the current model to the one stored in the Model Column of this table. Conclusion The important thing of this walk through is that we must create our initial migration before we start doing any changes to our model. This way we'll be adding the necessary __MigrationsHistory table to our existing database, so we can keep our database up to date with all the changes we do in our context model using migrations. Hope you have found this information useful. Please let us know if you have any questions or comments, also please check our forums here where we keep answering questions in general for the community. Happy MySQL/Net Coding!

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jQuery Templates, Data Link

- by Renso

Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Query Templates, Data Link, and Globalization I am sure you must have read Scott Guthrie’s blog post about jQuery support and officially supporting jQuery's templating, data linking and globalization, if not here it is: jQuery Templating Since we are an open source shop and use jQuery and jQuery plugins extensively to say the least, decided to look into the templating a bit and see what data linking is all about. For those not familiar with those terms here is the summary, plenty of material out there on what it is, but here is what in my experience it means: jQuery Templating: A templating engine that allows you to specify a client-side template where you indicate which properties/tags you want dynamically updated. You in a sense specify which parts of the html is dynamic and since it is pluggable you are able to use tools data jQuery data linking and others to let it sync up your template with data. What makes it more powerful is that you can easily work with rows of data, adding and removing rows. Once the template has been generated, which you do dynamically on a client-side event, you then append/inject the resulting template somewhere in your DOM, like for example you would get a JSON object from the database, map it to your template, it populates the template with your data in the indicated places, and then let’s say for example append it to a row in a table. I have not found it that useful for lets say a single record of data since you could easily just get a partial view from the server via an html type ajax call. It really shines when you dynamically add/remove rows from a list in the DOM. I have not found an alternative that meets the functionality of the jQuery template and helps of course that Microsoft officially supports it. In future versions of the jQuery plug-in it may even ship as part of the standard jQuery library and with future versions of Visual Studio. jQuery Data Linking: In short I was fascinated by it initially by how with one line of code I can sync up my JSON object with my form elements. That's where my enthusiasm stopped. It was one-line to let is deal with syncing up your form with your JSON object, but it is not bidirectional as they state and I tried all the work arounds they suggested and none of them work. The problem is that when you update your JSON object it DOES NOT sync it up with your form. In an example, accounts are being edited client side by selecting the account from a list by clicking on the row, it then fetches the entire account JSON object via ajax json-type call and then refreshes the form with the account’s details from the new JSON object. What is the use of syncing up my JSON with the form if I still have to programmatically sync up my new JSON object with each DOM property?! So you may ask: “what is the alternative”? Good question and the same one I was pondering, maybe I can just use it for keeping my from n sync with my JSON object so I can post that JSON object back to the server and update my database. That’s when I discovered Knockout: Knockout It addresses the issues mentioned above and also supports event handling through the observer pattern. Not wanting to go into detail here, Steve Sanderson, the creator of Knockout, has already done a terrific job of that, thanks Steve for a great plug-in! Best of all it integrates perfectly with the jQuery Templating engine as well. I have not found an alternative to this plugin that supports the depth and width of functionality and would recommend it to anyone. The only drawback is the embedded html attributes (data-bind=””) tags that you have to add to the HTML, in my opinion tying your behavior to your HTML, where I like to separate behavior from HTML as well as CSS, so the HTML is purely to define content, not styling or behavior. But there are plusses to this as well and also a nifty work around to this that I will just shortly mention here with an example. Instead of data binding an html tag with knockout event handling like so: <%=Html.TextBox("PrepayDiscount", String.Empty, new { @class = "number" })%> Do: <%=Html.DataBoundTextBox("PrepayDiscount", String.Empty, new { @class = "number" })%> The html extension above then takes care of the internals and you could then swap Knockout for something else if you want to inside the extension and keep the HTML plugin agnostic. Here is what the extension looks like, you can easily build a whole library to support all kinds of data binding options from this: public static class HtmlExtensions { public static MvcHtmlString DataBoundTextBox(this HtmlHelper helper, string name, object value, object htmlAttributes) { var dic = new RouteValueDictionary(htmlAttributes); dic.Add("data-bind", String.Format("value: {0}", name)); return helper.TextBox(name, value, dic); } } Hope this helps in making a decision when and where to consider jQuery templating, data linking and Knockout.

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Oracle NoSQL Database Exceeds 1 Million Mixed YCSB Ops/Sec

- by Charles Lamb

We ran a set of YCSB performance tests on Oracle NoSQL Database using SSD cards and Intel Xeon E5-2690 CPUs with the goal of achieving 1M mixed ops/sec on a 95% read / 5% update workload. We used the standard YCSB parameters: 13 byte keys and 1KB data size (1,102 bytes after serialization). The maximum database size was 2 billion records, or approximately 2 TB of data. We sized the shards to ensure that this was not an "in-memory" test (i.e. the data portion of the B-Trees did not fit into memory). All updates were durable and used the "simple majority" replica ack policy, effectively 'committing to the network'. All read operations used the Consistency.NONE_REQUIRED parameter allowing reads to be performed on any replica. In the past we have achieved 100K ops/sec using SSD cards on a single shard cluster (replication factor 3) so for this test we used 10 shards on 15 Storage Nodes with each SN carrying 2 Rep Nodes and each RN assigned to its own SSD card. After correcting a scaling problem in YCSB, we blew past the 1M ops/sec mark with 8 shards and proceeded to hit 1.2M ops/sec with 10 shards. Hardware Configuration We used 15 servers, each configured with two 335 GB SSD cards. We did not have homogeneous CPUs across all 15 servers available to us so 12 of the 15 were Xeon E5-2690, 2.9 GHz, 2 sockets, 32 threads, 193 GB RAM, and the other 3 were Xeon E5-2680, 2.7 GHz, 2 sockets, 32 threads, 193 GB RAM. There might have been some upside in having all 15 machines configured with the faster CPU, but since CPU was not the limiting factor we don't believe the improvement would be significant. The client machines were Xeon X5670, 2.93 GHz, 2 sockets, 24 threads, 96 GB RAM. Although the clients had 96 GB of RAM, neither the NoSQL Database or YCSB clients require anywhere near that amount of memory and the test could have just easily been run with much less. Networking was all 10GigE. YCSB Scaling Problem We made three modifications to the YCSB benchmark. The first was to allow the test to accommodate more than 2 billion records (effectively int's vs long's). To keep the key size constant, we changed the code to use base 32 for the user ids. The second change involved to the way we run the YCSB client in order to make the test itself horizontally scalable.The basic problem has to do with the way the YCSB test creates its Zipfian distribution of keys which is intended to model "real" loads by generating clusters of key collisions. Unfortunately, the percentage of collisions on the most contentious keys remains the same even as the number of keys in the database increases. As we scale up the load, the number of collisions on those keys increases as well, eventually exceeding the capacity of the single server used for a given key.This is not a workload that is realistic or amenable to horizontal scaling. YCSB does provide alternate key distribution algorithms so this is not a shortcoming of YCSB in general. We decided that a better model would be for the key collisions to be limited to a given YCSB client process. That way, as additional YCSB client processes (i.e. additional load) are added, they each maintain the same number of collisions they encounter themselves, but do not increase the number of collisions on a single key in the entire store. We added client processes proportionally to the number of records in the database (and therefore the number of shards). This change to the use of YCSB better models a use case where new groups of users are likely to access either just their own entries, or entries within their own subgroups, rather than all users showing the same interest in a single global collection of keys. If an application finds every user having the same likelihood of wanting to modify a single global key, that application has no real hope of getting horizontal scaling. Finally, we used read/modify/write (also known as "Compare And Set") style updates during the mixed phase. This uses versioned operations to make sure that no updates are lost. This mode of operation provides better application behavior than the way we have typically run YCSB in the past, and is only practical at scale because we eliminated the shared key collision hotspots.It is also a more realistic testing scenario. To reiterate, all updates used a simple majority replica ack policy making them durable. Scalability Results In the table below, the "KVS Size" column is the number of records with the number of shards and the replication factor. Hence, the first row indicates 400m total records in the NoSQL Database (KV Store), 2 shards, and a replication factor of 3. The "Clients" column indicates the number of YCSB client processes. "Threads" is the number of threads per process with the total number of threads. Hence, 90 threads per YCSB process for a total of 360 threads. The client processes were distributed across 10 client machines. Shards KVS Size Clients Mixed (records) Threads OverallThroughput(ops/sec) Read Latencyav/95%/99%(ms) Write Latencyav/95%/99%(ms) 2 400m(2x3) 4 90(360) 302,152 0.76/1/3 3.08/8/35 4 800m(4x3) 8 90(720) 558,569 0.79/1/4 3.82/16/45 8 1600m(8x3) 16 90(1440) 1,028,868 0.85/2/5 4.29/21/51 10 2000m(10x3) 20 90(1800) 1,244,550 0.88/2/6 4.47/23/53

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JavaDay Taipei 2014 Trip Report

- by reza_rahman

JavaDay Taipei 2014 was held at the Taipei International Convention Center on August 1st. Organized by Oracle University, it is one of the largest Java developer events in Taiwan. This was another successful year for JavaDay Taipei with a fully sold out venue packed with youthful, energetic developers (this was my second time at the event and I have already been invited to speak again next year!). In addition to Oracle speakers like me, Steve Chin and Naveen Asrani, the event also featured a bevy of local speakers including Taipei Java community leaders. Topics included Java SE, Java EE, JavaFX, cloud and Big Data. It was my pleasure and privilege to present one of the opening keynotes for the event. I presented my session on Java EE titled "JavaEE.Next(): Java EE 7, 8, and Beyond". I covered the changes in Java EE 7 as well as what's coming in Java EE 8. I demoed the Cargo Tracker Java EE BluePrints. I also briefly talked about Adopt-a-JSR for Java EE 8. The slides for the keynote are below (click here to download and view the actual PDF): It appears your Web browser is not configured to display PDF files. No worries, just click here to download the PDF file. In the afternoon I did my JavaScript + Java EE 7 talk titled "Using JavaScript/HTML5 Rich Clients with Java EE 7". This talk is basically about aligning EE 7 with the emerging JavaScript ecosystem (specifically AngularJS). The talk was completely packed. The slide deck for the talk is here: JavaScript/HTML5 Rich Clients Using Java EE 7 from Reza Rahman The demo application code is posted on GitHub. The code should be a helpful resource if this development model is something that interests you. Do let me know if you need help with it but the instructions should be fairly self-explanatory. I am delivering this material at JavaOne 2014 as a two-hour tutorial. This should give me a little more bandwidth to dig a little deeper, especially on the JavaScript end. I finished off Java Day Taipei with my talk titled "Using NoSQL with ~JPA, EclipseLink and Java EE" (this was the last session of the conference). The talk covers an interesting gap that there is surprisingly little material on out there. The talk has three parts -- a birds-eye view of the NoSQL landscape, how to use NoSQL via a JPA centric facade using EclipseLink NoSQL, Hibernate OGM, DataNucleus, Kundera, Easy-Cassandra, etc and how to use NoSQL native APIs in Java EE via CDI. The slides for the talk are here: Using NoSQL with ~JPA, EclipseLink and Java EE from Reza Rahman The JPA based demo is available here, while the CDI based demo is available here. Both demos use MongoDB as the data store. Do let me know if you need help getting the demos up and running. After the event the Oracle University folks hosted a reception in the evening which was very well attended by organizers, speakers and local Java community leaders. I am extremely saddened by the fact that this otherwise excellent trip was scarred by terrible tragedy. After the conference I joined a few folks for a hike on the Maokong Mountain on Saturday. The group included friends in the Taiwanese Java community including Ian and Robbie Cheng. Without warning, fatal tragedy struck on a remote part of the trail. Despite best efforts by us, the excellent Taiwanese Emergency Rescue Team and World class Taiwanese physicians we were unable to save our friend Robbie Cheng's life. Robbie was just thirty-four years old and is survived by his younger brother, mother and father. Being the father of a young child myself, I can only imagine the deep sorrow that this senseless loss unleashes. Robbie was a key member of the Taiwanese Java community and a Java Evangelist at Sun at one point. Ironically the only picture I was able to take of the trail was mere moments before tragedy. I thought I should place him in that picture in profoundly respectful memoriam: Perhaps there is some solace in the fact that there is something inherently honorable in living a bright life, dying young and meeting one's end on a beautiful remote mountain trail few venture to behold let alone attempt to ascend in a long and tired lifetime. Perhaps I'd even say it's a fate I would not entirely regret facing if it were my own. With that thought in mind it seems appropriate to me to quote some lyrics from the song "Runes to My Memory" by legendary Swedish heavy metal band Amon Amarth idealizing a fallen Viking warrior cut down in his prime: "Here I lie on wet sand I will not make it home I clench my sword in my hand Say farewell to those I love When I am dead Lay me in a mound Place my weapons by my side For the journey to Hall up high When I am dead Lay me in a mound Raise a stone for all to see Runes carved to my memory" I submit my deepest condolences to Robbie's family and hope my next trip to Taiwan ends in a less somber note.

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Rebuilding CoasterBuzz, Part IV: Dependency injection, it's what's for breakfast

- by Jeff

(Repost from my personal blog.) This is another post in a series about rebuilding one of my Web sites, which has been around for 12 years. I hope to relaunch soon. More: Part I: Evolution, and death to WCF Part II: Hot data objects Part III: The architecture using the "Web stack of love" If anything generally good for the craft has come out of the rise of ASP.NET MVC, it's that people are more likely to use dependency injection, and loosely couple the pieces parts of their applications. A lot of the emphasis on coding this way has been to facilitate unit testing, and that's awesome. Unit testing makes me feel a lot less like a hack, and a lot more confident in what I'm doing. Dependency injection is pretty straight forward. It says, "Given an instance of this class, I need instances of other classes, defined not by their concrete implementations, but their interfaces." Probably the first place a developer exercises this in when having a class talk to some kind of data repository. For a very simple example, pretend the FooService has to get some Foo. It looks like this: public class FooService { public FooService(IFooRepository fooRepo) { _fooRepo = fooRepo; } private readonly IFooRepository _fooRepo; public Foo GetMeFoo() { return _fooRepo.FooFromDatabase(); } } When we need the FooService, we ask the dependency container to get it for us. It says, "You'll need an IFooRepository in that, so let me see what that's mapped to, and put it in there for you." Why is this good for you? It's good because your FooService doesn't know or care about how you get some foo. You can stub out what the methods and properties on a fake IFooRepository might return, and test just the FooService. I don't want to get too far into unit testing, but it's the most commonly cited reason to use DI containers in MVC. What I wanted to mention is how there's another benefit in a project like mine, where I have to glue together a bunch of stuff. For example, when I have someone sign up for a new account on CoasterBuzz, I'm actually using POP Forums' new account mailer, which composes a bunch of text that includes a link to verify your account. The thing is, I want to use custom text and some other logic that's specific to CoasterBuzz. To accomplish this, I make a new class that inherits from the forum's NewAccountMailer, and override some stuff. Easy enough. Then I use Ninject, the DI container I'm using, to unbind the forum's implementation, and substitute my own. Ninject uses something called a NinjectModule to bind interfaces to concrete implementations. The forum has its own module, and then the CoasterBuzz module is loaded second. The CB module has two lines of code to swap out the mailer implementation: Unbind<PopForums.Email.INewAccountMailer>(); Bind<PopForums.Email.INewAccountMailer>().To<CbNewAccountMailer>(); Piece of cake! Now, when code asks the DI container for an INewAccountMailer, it gets my custom implementation instead. This is a lot easier to deal with than some of the alternatives. I could do some copy-paste, but then I'm not using well-tested code from the forum. I could write stuff from scratch, but then I'm throwing away a bunch of logic I've already written (in this case, stuff around e-mail, e-mail settings, mail delivery failures). There are other places where the DI container comes in handy. For example, CoasterBuzz does a number of custom things with user profiles, and special content for paid members. It uses the forum as the core piece to managing users, so I can ask the container to get me instances of classes that do user lookups, for example, and have zero care about how the forum handles database calls, configuration, etc. What a great world to live in, compared to ten years ago. Sure, the primary interest in DI is around the "separation of concerns" and facilitating unit testing, but as your library grows and you use more open source, it starts to be the glue that pulls everything together.

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Common reasons for the ‘Sys is undefined’ error in ASP.NET Ajax applications

In this blog I will try to summarize the most common reasons for getting the famous 'Sys is undefined' error when running an Ajax enabled web site or application (there are almost one milion results on Google for that phrase). Where does it come from? In every Ajax web pages source you will see a code like this: <script type="text/javascript"> //<![CDATA[ Sys.WebForms.PageRequestManager._initialize('ScriptManager1', document.getElementById('form1')); Sys.WebForms.PageRequestManager.getInstance()._updateControls([], [], [], 90); //]]> </script> This is the initialization script of the ScriptManager. So, if for some reason the Sys namespace is not available when the code executes you get the Sys is undefined error. Here are the most common reasons and solutions for that problem: 1. The error occurs when you have added a control from RadControls for ASP.NET AJAX, but your application is not configured to use ASP.NET AJAX. For example, in VS 2005 you created a new Blank Site instead of a new Ajax-Enabled Web Site and the Sys is undefined message pops up. To fix it you need to follow the steps described at Configuring ASP.NET Ajax article (check the topic called Adding ASP.NET AJAX Configuration Elements to an Existing Web Site) or simply create the Ajax-Enabled Web Site. You can also check my other blog post on the matter: Visual Studio 2008: Where is the new ASP.NET Ajax-Enabled Web Site template? 2. Authentication - as the website denies access to all pages to unauthorized users, access to the Telerik.Web.UI.WebResource.axd handler is unauthorized (this is the default handler of RadScriptManager). This causes the handler to serve the content of the login page instead of the combined scripts, hence the error. To solve it - add a <location> section to the application configuration file to allow access to Telerik.Web.UI.WebResource.axd to all users, like: <configuration> ... <location path="Telerik.Web.UI.WebResource.axd"> <system.web> <authorization> <allow users="*"/> </authorization> </system.web> </location> ... </configuration> Note that the access to the standard ScriptResource.axd and WebResource.axd is automatically allowed for all users (authenticated and unauthenticated), so if you use the ScriptManager instead of RadScriptManager - you will not face this problem. The authentication problem does not manifest when you disable script combining or use the CDN. Adding the above configuration section will make it work with RadScriptManagers combined script. 3. The IE6 browser fails to load the compressed script. The problem does not appear in any other browser. There is a well known bug in the older versions of IE6 which lose the first 2,048 bytes of data that are sent back from a Web server that uses HTTP compression. Latest versions of RadScriptManager does not compress the output at all if the client is IE6, but in the previous versions you need to manually disable the output compression to prevent the error. So, if you get the Sys is undefined error in IE6 - update to the latest version of RadControls or simply disable the output compression. 4. Requests to the *.axd files returns Error Code 404 - Not Found. This could be fixed easily: Check in the IIS management console that the .axd extension (the default HTTP handler extension) is allowed: Also check if the Verify if file exists checkbox is unchecked (click on the Edit button appearing in the previous screenshot to check). More information can be found in our troubleshooting article and from the ASP.NET QA team blog post 5. The virtual directory in IIS is not marked as Web Application. Converting it to Web Application should fix the problem. 6. Check for the <xhtmlConformance mode="Legacy"/> option in your web.config and remove it. It would be rather rare to become a victim of this exact case, but still have it in mind. Scott Guthrie describes it in more details In the above points I mentioned several times the terms web resources, javascript output, compressed script. If you want to find out more about these please see the Web Resources Demystified series of my friend and colleague Atanas Korchev I hope that one of the above solutions will help you get rid of the Sys is undefined error. 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.

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SQL SERVER – Backing Up and Recovering the Tail End of a Transaction Log – Notes from the Field #042

- by Pinal Dave

[Notes from Pinal]: The biggest challenge which people face is not taking backup, but the biggest challenge is to restore a backup successfully. I have seen so many different examples where users have failed to restore their database because they made some mistake while they take backup and were not aware of the same. Tail Log backup was such an issue in earlier version of SQL Server but in the latest version of SQL Server, Microsoft team has fixed the confusion with additional information on the backup and restore screen itself. Now they have additional information, there are a few more people confused as they have no clue about this. Previously they did not find this as a issue and now they are finding tail log as a new learning. Linchpin People are database coaches and wellness experts for a data driven world. In this 42nd episode of the Notes from the Fields series database expert Tim Radney (partner at Linchpin People) explains in a very simple words, Backing Up and Recovering the Tail End of a Transaction Log. Many times when restoring a database over an existing database SQL Server will warn you about needing to make a tail end of the log backup. This might be your reminder that you have to choose to overwrite the database or could be your reminder that you are about to write over and lose any transactions since the last transaction log backup. You might be asking yourself “What is the tail end of the transaction log”. The tail end of the transaction log is simply any committed transactions that have occurred since the last transaction log backup. This is a very crucial part of a recovery strategy if you are lucky enough to be able to capture this part of the log. Most organizations have chosen to accept some amount of data loss. You might be shaking your head at this statement however if your organization is taking transaction logs backup every 15 minutes, then your potential risk of data loss is up to 15 minutes. Depending on the extent of the issue causing you to have to perform a restore, you may or may not have access to the transaction log (LDF) to be able to back up those vital transactions. For example, if the storage array or disk that holds your transaction log file becomes corrupt or damaged then you wouldn’t be able to recover the tail end of the log. If you do have access to the physical log file then you can still back up the tail end of the log. In 2013 I presented a session at the PASS Summit called “The Ultimate Tail Log Backup and Restore” and have been invited back this year to present it again. During this session I demonstrate how you can back up the tail end of the log even after the data file becomes corrupt. In my demonstration I set my database offline and then delete the data file (MDF). The database can’t become more corrupt than that. I attempt to bring the database back online to change the state to RECOVERY PENDING and then backup the tail end of the log. I can do this by specifying WITH NO_TRUNCATE. Using NO_TRUNCATE is equivalent to specifying both COPY_ONLY and CONTINUE_AFTER_ERROR. It as its name says, does not try to truncate the log. This is a great demo however how could I achieve backing up the tail end of the log if the failure destroys my entire instance of SQL and all I had was the LDF file? During my demonstration I also demonstrate that I can attach the log file to a database on another instance and then back up the tail end of the log. If I am performing proper backups then my most recent full, differential and log files should be on a server other than the one that crashed. I am able to achieve this task by creating new database with the same name as the failed database. I then set the database offline, delete my data file and overwrite the log with my good log file. I attempt to bring the database back online and then backup the log with NO_TRUNCATE just like in the first example. I encourage each of you to view my blog post and watch the video demonstration on how to perform these tasks. I really hope that none of you ever have to perform this in production, however it is a really good idea to know how to do this just in case. It really isn’t a matter of “IF” you will have to perform a restore of a production system but more of a “WHEN”. Being able to recover the tail end of the log in these sever cases could be the difference of having to notify all your business customers of data loss or not. If you want me to take a look at your server and its settings, or if your server is facing any issue we can Fix Your SQL Server. Note: Tim has also written an excellent book on SQL Backup and Recovery, a must have for everyone. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: Notes from the Field, PostADay, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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What Counts for a DBA: Humility

- by drsql

In football (the American sort, naturally,) there are a select group of players who really hope to never have their names called during the game. They are members of the offensive line, and their job is to protect other players so they can deliver the ball to the goal to score points. When you do hear their name called, it is usually because they made a mistake and the player that they were supposed to protect ended up flat on his back admiring the clouds in the sky instead of advancing towards the goal to scoring point. Even on the rare occasion their name is called for a good reason, it is usually because they were making up for a teammate who had made a mistake and they covered up for them. The role of offensive lineman is a very good analogy for the role of the admin DBA. As a DBA, you are called on to be barely visible and rarely heard, protecting the company data assets tenaciously, even though the enemies to our craft surround us on all sides:. Developers: Cries of ‘foul!’ often ensue when the DBA says that they want data integrity to be stringently enforced and that documentation is needed so they can support systems, mostly because every error occurrence in the enterprise will be initially blamed on the database and fall to the DBA to troubleshoot. Insisting too loudly may bring those cries of ‘foul’ that somewhat remind you of when your 2 year old daughter didn't want to go to bed. The result of this petulance is that the next "enemy" gets involved. Managers: The concerns that motivate DBAs to argue will not excite the kind of manager who gets his technical knowledge from a glossy magazine filled with buzzwords, charts, and pretty pictures. However, the other programmers in the organization will tickle the buzzword void with a stream of new-sounding ideas and technologies constantly, along with warnings that if we did care about data integrity and document things, the budget would explode! In contrast, the arguments for integrity of data and supportability tend to be about as exciting as watching grass grow, and far too many manager types seem to prefer to smoke it than watch it. Packaged Applications: The DBA is rarely given a chance to review a new application that is being demonstrated for the enterprise, and rarer still is the DBA that gets a veto of an application because the database it uses has clearly been created by an architect that won't read a data modeling book because he is already married. More often than not this leads to hours of work for the DBA trying to performance-tune a database with a menagerie of rules that must be followed to stay within the application support agreement, such as no changing indexes on a third party schema even though there are 10 billion rows instead of the 10 thousand when the system was last optimized. Hardware Failures: Physical disks, networking devices, memory, and backup devices all come with a measure known as ‘mean time before failure’ and it is never listed in centuries or eons. More like years, and the term ‘mean’ indicates that half of the devices are expected to fail before that, which by my calendar means any hour of any day that it wants to fail it will. But the DBA sucks it up and does the task at hand with a humility that makes them nearly invisible to all but the most observant person in the organization. The best DBAs I know are so proactive in their relentless pursuit of perfection that they detect many of the bugs (which they seldom caused) in the system well before they become a problem. In the end the DBA gets noticed for one of same two reasons as the offensive lineman. You make a mistake, like dropping a critical production database that had never been backed up; or when a system crashes for any reason whatsoever and they are on the spot with troubleshooting and system restoration plans that have been well thought out, tested, and tested again. Not because there is any glory in it, but because it is what they do. Note: The characteristics of the professions referred to in this blog are meant to be overstated stereotypes for humorous effect, and even some DBAs aren't quite this perfect. If you are reading this far and haven’t hand written a 10 page flaming comment about how you are a _______ and you aren’t like this, that is awesome. Not every situation applies to everyone, but if you have never worked with a bad packaged app, a magazine trained manager, programmers that aren’t team players, or hardware that occasionally failed, relax and go have a unicorn sandwich before you wake up.

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A Knights Tale

- by Phil Factor

There are so many lessons to be learned from the story of Knight Capital losing nearly half a billion dollars as a result of a deployment gone wrong. The Knight Capital Group (KCG N) was an American global financial services firm engaging in market making, electronic execution, and institutional sales and trading. According to the recent order (File No.3.15570) against Knight Capital by U.S. Securities and Exchange Commission?, Knight had, for many years used some software which broke up incoming “parent” orders into smaller “child” orders that were then transmitted to various exchanges or trading venues for execution. A tracking ‘cumulative quantity’ function counted the number of ‘child’ orders and stopped the process once the total of child orders matched the ‘parent’ and so the parent order had been completed. Back in the mists of time, some code had been added to it which was excuted if a particular flag was set. It was called ‘power peg’ and seems to have had a similar design and purpose, but, one guesses, would have shared the same tracking function. This code had been abandoned in 2003, but never deleted. In 2005, The tracking function was moved to an earlier point in the main process. It would seem from the account that, from that point, had that flag ever been set, the old ‘Power Peg’ would have been executed like Godzilla bursting from the ice, making child orders without limit without any tracking function. It wasn’t, presumably because the software that set the flag was removed. In 2012, nearly a decade after ‘Power Peg’ was abandoned, Knight prepared a new module to their software to cope with the imminent Retail Liquidity Program (RLP) for the New York Stock Exchange. By this time, the flag had remained unused and someone made the fateful decision to reuse it, and replace the old ‘power peg’ code with this new RLP code. Had the two actions been done together in a single automated deployment, and the new deployment tested, all would have been well. It wasn’t. To quote… “Beginning on July 27, 2012, Knight deployed the new RLP code in SMARS in stages by placing it on a limited number of servers in SMARS on successive days. During the deployment of the new code, however, one of Knight’s technicians did not copy the new code to one of the eight SMARS computer servers. Knight did not have a second technician review this deployment and no one at Knight realized that the Power Peg code had not been removed from the eighth server, nor the new RLP code added. Knight had no written procedures that required such a review.” (para 15) “On August 1, Knight received orders from broker-dealers whose customers were eligible to participate in the RLP. The seven servers that received the new code processed these orders correctly. However, orders sent with the repurposed flag to the eighth server triggered the defective Power Peg code still present on that server. As a result, this server began sending child orders to certain trading centers for execution. Because the cumulative quantity function had been moved, this server continuously sent child orders, in rapid sequence, for each incoming parent order without regard to the number of share executions Knight had already received from trading centers. Although one part of Knight’s order handling system recognized that the parent orders had been filled, this information was not communicated to SMARS.” (para 16) SMARS routed millions of orders into the market over a 45-minute period, and obtained over 4 million executions in 154 stocks for more than 397 million shares. By the time that Knight stopped sending the orders, Knight had assumed a net long position in 80 stocks of approximately $3.5 billion and a net short position in 74 stocks of approximately $3.15 billion. Knight’s shares dropped more than 20% after traders saw extreme volume spikes in a number of stocks, including preferred shares of Wells Fargo (JWF) and semiconductor company Spansion (CODE). Both stocks, which see roughly 100,000 trade per day, had changed hands more than 4 million times by late morning. Ultimately, Knight lost over $460 million from this wild 45 minutes of trading. Obviously, I’m interested in all this because, at one time, I used to write trading systems for the City of London. Obviously, the US SEC is in a far better position than any of us to work out the failings of Knight’s IT department, and the report makes for painful reading. I can’t help observing, though, that even with the breathtaking mistakes all along the way, that a robust automated deployment process that was ‘all-or-nothing’, and tested from soup to nuts would have prevented the disaster. The report reads like a Greek Tragedy. All the way along one wants to shout ‘No! not that way!’ and ‘Aargh! Don’t do it!’. As the tragedy unfolds, the audience weeps for the players, trapped by a cruel fate. All application development and deployment requires defense in depth. All IT goes wrong occasionally, but if there is a culture of defensive programming throughout, the consequences are usually containable. For financial systems, these defenses are required by statute, and ignored only by the foolish. Knight’s mistakes weren’t made by just one hapless sysadmin, but were progressive errors by an IT culture spanning at least ten years. One can spell these out, but I think they’re obvious. One can only hope that the industry studies what happened in detail, learns from the mistakes, and draws the right conclusions.

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A Patent for Workload Management Based on Service Level Objectives

- by jsavit

I'm very pleased to announce that after a tiny :-) wait of about 5 years, my patent application for a workload manager was finally approved. Background Many operating systems have a resource manager which lets you control machine resources. For example, Solaris provides controls for CPU with several options: shares for proportional CPU allocation. If you have twice as many shares as me, and we are competing for CPU, you'll get about twice as many CPU cycles), dedicated CPU allocation in which a number of CPUs are exclusively dedicated to an application's use. You can say that a zone or project "owns" 8 CPUs on a 32 CPU machine, for example. And, capped CPU in which you specify the upper bound, or cap, of how much CPU an application gets. For example, you can throttle an application to 0.125 of a CPU. (This isn't meant to be an exhaustive list of Solaris RM controls.) Workload management Useful as that is (and tragic that some other operating systems have little resource management and isolation, and frighten people into running only 1 app per OS instance - and wastefully size every server for the peak workload it might experience) that's not really workload management. With resource management one controls the resources, and hope that's enough to meet application service objectives. In fact, we hold resource distribution constant, see if that was good enough, and adjust resource distribution if that didn't meet service level objectives. Here's an example of what happens today: Let's try 30% dedicated CPU. Not enough? Let's try 80% Oh, that's too much, and we're achieving much better response time than the objective, but other workloads are starving. Let's back that off and try again. It's not the process I object to - it's that we to often do this manually. Worse, we sometimes identify and adjust the wrong resource and fiddle with that to no useful result. Back in my days as a customer managing large systems, one of my users would call me up to beg for a "CPU boost": Me: "it won't make any difference - there's plenty of spare CPU to be had, and your application is completely I/O bound." User: "Please do it anyway." Me: "oh, all right, but it won't do you any good." (I did, because he was a friend, but it didn't help.) Prior art There are some operating environments that take a stab about workload management (rather than resource management) but I find them lacking. I know of one that uses synthetic "service units" composed of the sum of CPU, I/O and memory allocations multiplied by weighting factors. A workload is set to make a target rate of service units consumed per second. But this seems to be missing a key point: what is the relationship between artificial 'service units' and actually meeting a throughput or response time objective? What if I get plenty of one of the components (so am getting enough service units), but not enough of the resource whose needed to remove the bottleneck? Actual workload management That's not really the answer either. What is needed is to specify a workload's service levels in terms of externally visible metrics that are meaningful to a business, such as response times or transactions per second, and have the workload manager figure out which resources are not being adequately provided, and then adjust it as needed. If an application is not meeting its service level objectives and the reason is that it's not getting enough CPU cycles, adjust its CPU resource accordingly. If the reason is that the application isn't getting enough RAM to keep its working set in memory, then adjust its RAM assignment appropriately so it stops swapping. Simple idea, but that's a task we keep dumping on system administrators. In other words - don't hold the number of CPU shares constant and watch the achievement of service level vary. Instead, hold the service level constant, and dynamically adjust the number of CPU shares (or amount of other resources like RAM or I/O bandwidth) in order to meet the objective. Instrumenting non-instrumented applications There's one little problem here: how do I measure application performance in a way relating to a service level. I don't want to do it based on internal resources like number of CPU seconds it received per minute - We need to make resource decisions based on externally visible and meaningful measures of performance, not synthetic items or internal resource counters. If I have a way of marking the beginning and end of a transaction, I can then measure whether or not the application is meeting an objective based on it. If I can observe the delay factors for an application, I can see which resource shortages are slowing an application enough to keep it from meeting its objectives. I can then adjust resource allocations to relieve those shortages. Fortunately, Solaris provides facilities for both marking application progress and determining what factors cause application latency. The Solaris DTrace facility let's me introspect on application behavior: in particular I can see events like "receive a web hit" and "respond to that web hit" so I can get transaction rate and response time. DTrace (and tools like prstat) let me see where latency is being added to an application, so I know which resource to adjust. Summary After a delay of a mere few years, I am the proud creator of a patent (advice to anyone interested in going through the process: don't hold your breath!). The fundamental idea is fairly simple: instead of holding resource constant and suffering variable levels of success meeting service level objectives, properly characterise the service level objective in meaningful terms, instrument the application to see if it's meeting the objective, and then have a workload manager change resource allocations to remove delays preventing service level attainment. I've done it by hand for a long time - I think that's what a computer should do for me.

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How to get distinct values from the List<T> with LINQ

- by Vincent Maverick Durano

Recently I was working with data from a generic List<T> and one of my objectives is to get the distinct values that is found in the List. Consider that we have this simple class that holds the following properties: public class Product { public string Make { get; set; } public string Model { get; set; } } Now in the page code behind we will create a list of product by doing the following: private List<Product> GetProducts() { List<Product> products = new List<Product>(); Product p = new Product(); p.Make = "Samsung"; p.Model = "Galaxy S 1"; products.Add(p); p = new Product(); p.Make = "Samsung"; p.Model = "Galaxy S 2"; products.Add(p); p = new Product(); p.Make = "Samsung"; p.Model = "Galaxy Note"; products.Add(p); p = new Product(); p.Make = "Apple"; p.Model = "iPhone 4"; products.Add(p); p = new Product(); p.Make = "Apple"; p.Model = "iPhone 4s"; products.Add(p); p = new Product(); p.Make = "HTC"; p.Model = "Sensation"; products.Add(p); p = new Product(); p.Make = "HTC"; p.Model = "Desire"; products.Add(p); p = new Product(); p.Make = "Nokia"; p.Model = "Some Model"; products.Add(p); p = new Product(); p.Make = "Nokia"; p.Model = "Some Model"; products.Add(p); p = new Product(); p.Make = "Sony Ericsson"; p.Model = "800i"; products.Add(p); p = new Product(); p.Make = "Sony Ericsson"; p.Model = "800i"; products.Add(p); return products; } And then let’s bind the products to the GridView. protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { Gridview1.DataSource = GetProducts(); Gridview1.DataBind(); } } Running the code will display something like this in the page: Now what I want is to get the distinct row values from the list. So what I did is to use the LINQ Distinct operator and unfortunately it doesn't work. In order for it work is you must use the overload method of the Distinct operator for you to get the desired results. So I’ve added this IEqualityComparer<T> class to compare values: class ProductComparer : IEqualityComparer<Product> { public bool Equals(Product x, Product y) { if (Object.ReferenceEquals(x, y)) return true; if (Object.ReferenceEquals(x, null) || Object.ReferenceEquals(y, null)) return false; return x.Make == y.Make && x.Model == y.Model; } public int GetHashCode(Product product) { if (Object.ReferenceEquals(product, null)) return 0; int hashProductName = product.Make == null ? 0 : product.Make.GetHashCode(); int hashProductCode = product.Model.GetHashCode(); return hashProductName ^ hashProductCode; } } After that you can then bind the GridView like this: protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { Gridview1.DataSource = GetProducts().Distinct(new ProductComparer()); Gridview1.DataBind(); } } Running the page will give you the desired output below: As you notice, it now eliminates the duplicate rows in the GridView. Now what if we only want to get the distinct values for a certain field. For example I want to get the distinct “Make” values such as Samsung, Apple, HTC, Nokia and Sony Ericsson and populate them to a DropDownList control for filtering purposes. I was hoping the the Distinct operator has an overload that can compare values based on the property value like (GetProducts().Distinct(o => o.PropertyToCompare). But unfortunately it doesn’t provide that overload so what I did as a workaround is to use the GroupBy,Select and First LINQ query operators to achieve what I want. Here’s the code to get the distinct values of a certain field. protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { DropDownList1.DataSource = GetProducts().GroupBy(o => o.Make).Select(o => o.First()); DropDownList1.DataTextField = "Make"; DropDownList1.DataValueField = "Model"; DropDownList1.DataBind(); } } Running the code will display the following output below: That’s it! I hope someone find this post useful!

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Clone a VirtualBox Machine

I just installed VirtualBox, which I want to try out based on recommendations from peers for running a server from within my Windows 7 x64 OS. Ive never used VirtualBox, so Im certainly no expert at it, but I did want to share my experience with it thus far. Specifically, my intention is to create a couple of virtual machines. One I intend to use as a build server, for which a virtual machine makes sense because I can easily move it around as needed if there are hardware issues (its worth noting my need for setting up a build server at the moment is a result of a disk failure on the old build server). The other VM I want to set up will act as a proxy server for the issue tracking system were using at Code Project, Axosoft OnTime. They have a Remote Server application for this purpose, and since the OnTime install is 300 miles away from my location, the Remote Server should speed up my use of the OnTime client by limiting the chattiness with the database (at least, thats the hope). So, I need two VMs, and Im lazy. I dont want to have to install the OS and such twice. No problem, it should be simple to clone a virtualbox machine, or clone a virtualbox hard drive, right? Well unfortunately, if you look at the UI for VirtualBox, theres no such command. Youre left wondering How do I clone a VirtualBox machine? or the slightly related How do I clone a VirtualBox hard drive? If youve used VirtualPC, then you know that its actually pretty easy to copy and move around those VMs. Not quite so easy with VirtualBox. Finding the files is easy, theyre located in your user folder within the .VirtualBox folder (possibly within a HardDisks folder). The disks have a .vdi extension and will be pretty large if youve installed anything. The one shown here has just Windows Server 2008 R2 installed on it nothing else. If you copy the .vdi file and rename it, you can use the Virtual Media Manager to view it and you can create a new machine and choose the new drive to attach to. Unfortunately, if you simply make a copy of the drive, this wont work and youll get an error that says something to the effect of: Cannot register the hard disk PATH with UUID {id goes here} because a hard disk PATH2 with UUID {same id goes here} already exists in the media registry (PATH to XML file). There are command line tools you can use to do this in a way that avoids this error. Specifically, the c:\Program File\Sun\VirtualBox\VBoxManage.exe program is used for all command line access to VirtualBox, and to copy a virtual disk (.vdi file) you would call something like this: VBoxManage clonehd Disk1.vdi Disk1_Copy.vdi However, in my case this didnt work. I got basically the same error I showed above, along with some debug information for line 628 of VBoxManageDisk.cpp. As my main task was not to debug the C++ code used to write VirtualBox, I continued looking for a simple way to clone a virtual drive. I found it in this blog post. The Secret setvdiuuid Command VBoxManage has a whole bunch of commands you can use with it just pass it /? to see the list. However, it also has a special command called internalcommands that opens up access to even more commands. The one thats interesting for us here is the setvdiuuid command. By calling this command and passing in the file path to your vdi file, it will reset the UUID to a new (random, apparently) UUID. This then allows the virtual media manager to cope with the file, and lets you set up new machines that reference the newly UUIDd virtual drive. The full command line would be: VBoxManage internalcommands setvdiuuid MyCopy.vdi The following screenshot shows the error when trying clonehd as well as the successful use of setvdiuuid. Summary Now that I can clone machines easily, its a simple matter to set up base builds of any OS I might need, and then fork from there as needed. Hopefully the GUI for VirtualBox will be improved to include better support for copying machines/disks, as this is Im sure a very common scenario. 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.

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2D isometric picking

- by Bikonja

I'm trying to implement picking in my isometric 2D game, however, I am failing. First of all, I've searched for a solution and came to several, different equations and even a solution using matrices. I tried implementing every single one, but none of them seem to work for me. The idea is that I have an array of tiles, with each tile having it's x and y coordinates specified (in this simplified example it's by it's position in the array). I'm thinking that the tile (0, 0) should be on the left, (max, 0) on top, (0, max) on the bottom and (max, max) on the right. I came up with this loop for drawing, which googling seems to have verified as the correct solution, as has the rendered scene (ofcourse, it could still be wrong, also, forgive the messy names and stuff, it's just a WIP proof of concept code) // Draw code int col = 0; int row = 0; for (int i = 0; i < nrOfTiles; ++i) { // XOffset and YOffset are currently hardcoded values, but will represent camera offset combined with HUD offset Point tile = IsoToScreen(col, row, TileWidth / 2, TileHeight / 2, XOffset, YOffset); int x = tile.X; int y = tile.Y; spriteBatch.Draw(_tiles[i], new Rectangle(tile.X, tile.Y, TileWidth, TileHeight), Color.White); col++; if (col >= Columns) // Columns is the number of tiles in a single row { col = 0; row++; } } // Get selection overlay location (removed check if selection exists for simplicity sake) Point tile = IsoToScreen(_selectedTile.X, _selectedTile.Y, TileWidth / 2, TileHeight / 2, XOffset, YOffset); spriteBatch.Draw(_selectionTexture, new Rectangle(tile.X, tile.Y, TileWidth, TileHeight), Color.White); // End of draw code public Point IsoToScreen(int isoX, int isoY, int widthHalf, int heightHalf, int xOffset, int yOffset) { Point newPoint = new Point(); newPoint.X = widthHalf * (isoX + isoY) + xOffset; newPoint.Y = heightHalf * (-isoX + isoY) + yOffset; return newPoint; } This code draws the tiles correctly. Now I wanted to do picking to select the tiles. For this, I tried coming up with equations of my own (including reversing the drawing equation) and I tried multiple solutions I found on the internet and none of these solutions worked. Trying out lots of solutions, I came upon one that didn't work, but it seemed like an axis was just inverted. I fiddled around with the equations and somehow managed to get it to actually work (but have no idea why it works), but while it's close, it still doesn't work. I'm not really sure how to describe the behaviour, but it changes the selection at wrong places, while being fairly close (sometimes spot on, sometimes a tile off, I believe never more off than the adjacent tile). This is the code I have for getting which tile coordinates are selected: public Point? ScreenToIso(int screenX, int screenY, int tileHeight, int offsetX, int offsetY) { Point? newPoint = null; int nX = -1; int nY = -1; int tX = screenX - offsetX; int tY = screenY - offsetY; nX = -(tY - tX / 2) / tileHeight; nY = (tY + tX / 2) / tileHeight; newPoint = new Point(nX, nY); return newPoint; } I have no idea why this code is so close, especially considering it doesn't even use the tile width and all my attempts to write an equation myself or use a solution I googled failed. Also, I don't think this code accounts for the area outside the "tile" (the transparent part of the tile image), for which I intend to add a color map, but even if that's true, it's not the problem as the selection sometimes switches on approx 25% or 75% of width or height. I'm thinking I've stumbled upon a wrong path and need to backtrack, but at this point, I'm not sure what to do so I hope someone can shed some light on my error or point me to the right path. It may be worth mentioning that my goal is to not only pick the tile. Each main tile will be divided into 5x5 smaller tiles which won't be drawn seperately from the whole main tile, but they will need to be picked out. I think a color map of a main tile with different colors for different coordinates within the main tile should take care of that though, which would fall within using a color map for the main tile (for the transparent parts of the tile, meaning parts that possibly belong to other tiles).

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Shallow Copy vs DeepCopy in C#.NET

Hope below example helps to understand the difference. Please drop a comment if any doubts. using System; using System.IO; using System.Runtime.Serialization.Formatters.Binary; namespace ShallowCopyVsDeepCopy { class Program { static void Main(string[] args) { var e1 = new Emp { EmpNo = 10, EmpName = "Smith", Department = new Dep { DeptNo = 100, DeptName = "Finance" } }; var e2 = e1.ShallowClone(); e1.Department.DeptName = "Accounts"; Console.WriteLine(e2.Department.DeptName); var e3 = new Emp { EmpNo = 10, EmpName = "Smith", Department = new Dep { DeptNo = 100, DeptName = "Finance" } }; var e4 = e3.DeepClone(); e3.Department.DeptName = "Accounts"; Console.WriteLine(e4.Department.DeptName); } } [Serializable] class Dep { public int DeptNo { get; set; } public String DeptName { get; set; } } [Serializable] class Emp { public int EmpNo { get; set; } public String EmpName { get; set; } public Dep Department { get; set; } public Emp ShallowClone() { return (Emp)this.MemberwiseClone(); } public Emp DeepClone() { MemoryStream ms = new MemoryStream(); BinaryFormatter bf = new BinaryFormatter(); bf.Serialize(ms, this); ms.Seek(0, SeekOrigin.Begin); object copy = bf.Deserialize(ms); ms.Close(); return copy as Emp; } } } span.fullpost {display:none;}

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UIView with IrrlichtScene - iOS

- by user1459024

i have a UIViewController in a Storyboard and want to draw a IrrlichtScene in this View Controller. My Code: WWSViewController.h #import <UIKit/UIKit.h> @interface WWSViewController : UIViewController { IBOutlet UILabel *errorLabel; } @end WWSViewController.mm #import "WWSViewController.h" #include "../../ressources/irrlicht/include/irrlicht.h" using namespace irr; using namespace core; using namespace scene; using namespace video; using namespace io; using namespace gui; @interface WWSViewController () @end @implementation WWSViewController -(void)awakeFromNib { errorLabel = [[UILabel alloc] init]; errorLabel.text = @""; IrrlichtDevice *device = createDevice( video::EDT_OGLES1, dimension2d<u32>(640, 480), 16, false, false, false, 0); /* Set the caption of the window to some nice text. Note that there is an 'L' in front of the string. The Irrlicht Engine uses wide character strings when displaying text. */ device->setWindowCaption(L"Hello World! - Irrlicht Engine Demo"); /* Get a pointer to the VideoDriver, the SceneManager and the graphical user interface environment, so that we do not always have to write device->getVideoDriver(), device->getSceneManager(), or device->getGUIEnvironment(). */ IVideoDriver* driver = device->getVideoDriver(); ISceneManager* smgr = device->getSceneManager(); IGUIEnvironment* guienv = device->getGUIEnvironment(); /* We add a hello world label to the window, using the GUI environment. The text is placed at the position (10,10) as top left corner and (260,22) as lower right corner. */ guienv->addStaticText(L"Hello World! This is the Irrlicht Software renderer!", rect<s32>(10,10,260,22), true); /* To show something interesting, we load a Quake 2 model and display it. We only have to get the Mesh from the Scene Manager with getMesh() and add a SceneNode to display the mesh with addAnimatedMeshSceneNode(). We check the return value of getMesh() to become aware of loading problems and other errors. Instead of writing the filename sydney.md2, it would also be possible to load a Maya object file (.obj), a complete Quake3 map (.bsp) or any other supported file format. By the way, that cool Quake 2 model called sydney was modelled by Brian Collins. */ IAnimatedMesh* mesh = smgr->getMesh("/Users/dbocksteger/Desktop/test/media/sydney.md2"); if (!mesh) { device->drop(); if (!errorLabel) { errorLabel = [[UILabel alloc] init]; } errorLabel.text = @"Konnte Mesh nicht laden."; return; } IAnimatedMeshSceneNode* node = smgr->addAnimatedMeshSceneNode( mesh ); /* To let the mesh look a little bit nicer, we change its material. We disable lighting because we do not have a dynamic light in here, and the mesh would be totally black otherwise. Then we set the frame loop, such that the predefined STAND animation is used. And last, we apply a texture to the mesh. Without it the mesh would be drawn using only a color. */ if (node) { node->setMaterialFlag(EMF_LIGHTING, false); node->setMD2Animation(scene::EMAT_STAND); node->setMaterialTexture( 0, driver->getTexture("/Users/dbocksteger/Desktop/test/media/sydney.bmp") ); } /* To look at the mesh, we place a camera into 3d space at the position (0, 30, -40). The camera looks from there to (0,5,0), which is approximately the place where our md2 model is. */ smgr->addCameraSceneNode(0, vector3df(0,30,-40), vector3df(0,5,0)); /* Ok, now we have set up the scene, lets draw everything: We run the device in a while() loop, until the device does not want to run any more. This would be when the user closes the window or presses ALT+F4 (or whatever keycode closes a window). */ while(device->run()) { /* Anything can be drawn between a beginScene() and an endScene() call. The beginScene() call clears the screen with a color and the depth buffer, if desired. Then we let the Scene Manager and the GUI Environment draw their content. With the endScene() call everything is presented on the screen. */ driver->beginScene(true, true, SColor(255,100,101,140)); smgr->drawAll(); guienv->drawAll(); driver->endScene(); } /* After we are done with the render loop, we have to delete the Irrlicht Device created before with createDevice(). In the Irrlicht Engine, you have to delete all objects you created with a method or function which starts with 'create'. The object is simply deleted by calling ->drop(). See the documentation at irr::IReferenceCounted::drop() for more information. */ device->drop(); } - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. } - (void)viewDidUnload { [super viewDidUnload]; // Release any retained subviews of the main view. } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown); } @end Sadly the result is just a black View in the Simulator. :( Hope here is anyone who can explain me how i draw the scene in a UIView. Furthermore I'm getting this Error: Could not load sprite bank because the file does not exist: #DefaultFont How can i fix it ?

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