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  • A Guided Tour of Complexity

    - by JoshReuben
    I just re-read Complexity – A Guided Tour by Melanie Mitchell , protégé of Douglas Hofstadter ( author of “Gödel, Escher, Bach”) http://www.amazon.com/Complexity-Guided-Tour-Melanie-Mitchell/dp/0199798109/ref=sr_1_1?ie=UTF8&qid=1339744329&sr=8-1 here are some notes and links:   Evolved from Cybernetics, General Systems Theory, Synergetics some interesting transdisciplinary fields to investigate: Chaos Theory - http://en.wikipedia.org/wiki/Chaos_theory – small differences in initial conditions (such as those due to rounding errors in numerical computation) yield widely diverging outcomes for chaotic systems, rendering long-term prediction impossible. System Dynamics / Cybernetics - http://en.wikipedia.org/wiki/System_Dynamics – study of how feedback changes system behavior Network Theory - http://en.wikipedia.org/wiki/Network_theory – leverage Graph Theory to analyze symmetric  / asymmetric relations between discrete objects Algebraic Topology - http://en.wikipedia.org/wiki/Algebraic_topology – leverage abstract algebra to analyze topological spaces There are limits to deterministic systems & to computation. Chaos Theory definitely applies to training an ANN (artificial neural network) – different weights will emerge depending upon the random selection of the training set. In recursive Non-Linear systems http://en.wikipedia.org/wiki/Nonlinear_system – output is not directly inferable from input. E.g. a Logistic map: Xt+1 = R Xt(1-Xt) Different types of bifurcations, attractor states and oscillations may occur – e.g. a Lorenz Attractor http://en.wikipedia.org/wiki/Lorenz_system Feigenbaum Constants http://en.wikipedia.org/wiki/Feigenbaum_constants express ratios in a bifurcation diagram for a non-linear map – the convergent limit of R (the rate of period-doubling bifurcations) is 4.6692016 Maxwell’s Demon - http://en.wikipedia.org/wiki/Maxwell%27s_demon - the Second Law of Thermodynamics has only a statistical certainty – the universe (and thus information) tends towards entropy. While any computation can theoretically be done without expending energy, with finite memory, the act of erasing memory is permanent and increases entropy. Life & thought is a counter-example to the universe’s tendency towards entropy. Leo Szilard and later Claude Shannon came up with the Information Theory of Entropy - http://en.wikipedia.org/wiki/Entropy_(information_theory) whereby Shannon entropy quantifies the expected value of a message’s information in bits in order to determine channel capacity and leverage Coding Theory (compression analysis). Ludwig Boltzmann came up with Statistical Mechanics - http://en.wikipedia.org/wiki/Statistical_mechanics – whereby our Newtonian perception of continuous reality is a probabilistic and statistical aggregate of many discrete quantum microstates. This is relevant for Quantum Information Theory http://en.wikipedia.org/wiki/Quantum_information and the Physics of Information - http://en.wikipedia.org/wiki/Physical_information. Hilbert’s Problems http://en.wikipedia.org/wiki/Hilbert's_problems pondered whether mathematics is complete, consistent, and decidable (the Decision Problem – http://en.wikipedia.org/wiki/Entscheidungsproblem – is there always an algorithm that can determine whether a statement is true).  Godel’s Incompleteness Theorems http://en.wikipedia.org/wiki/G%C3%B6del's_incompleteness_theorems  proved that mathematics cannot be both complete and consistent (e.g. “This statement is not provable”). Turing through the use of Turing Machines (http://en.wikipedia.org/wiki/Turing_machine symbol processors that can prove mathematical statements) and Universal Turing Machines (http://en.wikipedia.org/wiki/Universal_Turing_machine Turing Machines that can emulate other any Turing Machine via accepting programs as well as data as input symbols) that computation is limited by demonstrating the Halting Problem http://en.wikipedia.org/wiki/Halting_problem (is is not possible to know when a program will complete – you cannot build an infinite loop detector). You may be used to thinking of 1 / 2 / 3 dimensional systems, but Fractal http://en.wikipedia.org/wiki/Fractal systems are defined by self-similarity & have non-integer Hausdorff Dimensions !!!  http://en.wikipedia.org/wiki/List_of_fractals_by_Hausdorff_dimension – the fractal dimension quantifies the number of copies of a self similar object at each level of detail – eg Koch Snowflake - http://en.wikipedia.org/wiki/Koch_snowflake Definitions of complexity: size, Shannon entropy, Algorithmic Information Content (http://en.wikipedia.org/wiki/Algorithmic_information_theory - size of shortest program that can generate a description of an object) Logical depth (amount of info processed), thermodynamic depth (resources required). Complexity is statistical and fractal. John Von Neumann’s other machine was the Self-Reproducing Automaton http://en.wikipedia.org/wiki/Self-replicating_machine  . Cellular Automata http://en.wikipedia.org/wiki/Cellular_automaton are alternative form of Universal Turing machine to traditional Von Neumann machines where grid cells are locally synchronized with their neighbors according to a rule. Conway’s Game of Life http://en.wikipedia.org/wiki/Conway's_Game_of_Life demonstrates various emergent constructs such as “Glider Guns” and “Spaceships”. Cellular Automatons are not practical because logical ops require a large number of cells – wasteful & inefficient. There are no compilers or general program languages available for Cellular Automatons (as far as I am aware). Random Boolean Networks http://en.wikipedia.org/wiki/Boolean_network are extensions of cellular automata where nodes are connected at random (not to spatial neighbors) and each node has its own rule –> they demonstrate the emergence of complex  & self organized behavior. Stephen Wolfram’s (creator of Mathematica, so give him the benefit of the doubt) New Kind of Science http://en.wikipedia.org/wiki/A_New_Kind_of_Science proposes the universe may be a discrete Finite State Automata http://en.wikipedia.org/wiki/Finite-state_machine whereby reality emerges from simple rules. I am 2/3 through this book. It is feasible that the universe is quantum discrete at the plank scale and that it computes itself – Digital Physics: http://en.wikipedia.org/wiki/Digital_physics – a simulated reality? Anyway, all behavior is supposedly derived from simple algorithmic rules & falls into 4 patterns: uniform , nested / cyclical, random (Rule 30 http://en.wikipedia.org/wiki/Rule_30) & mixed (Rule 110 - http://en.wikipedia.org/wiki/Rule_110 localized structures – it is this that is interesting). interaction between colliding propagating signal inputs is then information processing. Wolfram proposes the Principle of Computational Equivalence - http://mathworld.wolfram.com/PrincipleofComputationalEquivalence.html - all processes that are not obviously simple can be viewed as computations of equivalent sophistication. Meaning in information may emerge from analogy & conceptual slippages – see the CopyCat program: http://cognitrn.psych.indiana.edu/rgoldsto/courses/concepts/copycat.pdf Scale Free Networks http://en.wikipedia.org/wiki/Scale-free_network have a distribution governed by a Power Law (http://en.wikipedia.org/wiki/Power_law - much more common than Normal Distribution). They are characterized by hubs (resilience to random deletion of nodes), heterogeneity of degree values, self similarity, & small world structure. They grow via preferential attachment http://en.wikipedia.org/wiki/Preferential_attachment – tipping points triggered by positive feedback loops. 2 theories of cascading system failures in complex systems are Self-Organized Criticality http://en.wikipedia.org/wiki/Self-organized_criticality and Highly Optimized Tolerance http://en.wikipedia.org/wiki/Highly_optimized_tolerance. Computational Mechanics http://en.wikipedia.org/wiki/Computational_mechanics – use of computational methods to study phenomena governed by the principles of mechanics. This book is a great intuition pump, but does not cover the more mathematical subject of Computational Complexity Theory – http://en.wikipedia.org/wiki/Computational_complexity_theory I am currently reading this book on this subject: http://www.amazon.com/Computational-Complexity-Christos-H-Papadimitriou/dp/0201530821/ref=pd_sim_b_1   stay tuned for that review!

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  • MVC Portable Areas &ndash; Web Application Projects

    - by Steve Michelotti
    This is the first post in a series related to build and deployment considerations as I’ve been exploring MVC Portable Areas: #1 – Using Web Application Project to build portable areas #2 – Conventions for deploying portable area static files #3 – Portable area static files as embedded resources Portable Areas is a relatively new feature available in MvcContrib that builds upon the new feature called Areas that was introduced in MVC 2. In short, portable areas provide a way to distribute MVC binary components as simple .NET assemblies rather than an assembly along with all the physical files for the views. At the heart of portable areas is a custom view engine that delivers the *.aspx pages by pulling them from embedded resources rather than from the physical file system. A portable area can be something as small as a tiny snippet of html that eventually gets rendered on a page, to something as large as an entire MVC web application. You should read this 4-part series to get up to speed on what portable areas are. Web Application Project In most of the posts to date, portable areas are shown being created with a simple C# class library. This is cool and it serves as an effective way to illustrate the simplicity of portable areas. However, the problem with that is that the developer loses out on the normal developer experience with the various tooling/scaffolding options that we’ve come to expect in visual studio like the ability to add controllers, views, etc. easily: I’ve had good results just using a normal web application project (rather than a class library) to develop portable areas and get the normal vs.net benefits. However, one gotcha that comes as a result is that it’s easy to forget to set the file to “Embedded Resource” every time you add a new aspx page. To mitigate this, simply add this MSBuild snippet shown below to your *.csproj file and all *.aspx, *ascx will automatically be set as embedded resources when your project compiles: 1: <Target Name="BeforeBuild"> 2: <ItemGroup> 3: <EmbeddedResource Include="**\*.aspx;**\*.ascx" /> 4: </ItemGroup> 5: </Target> Also, you should remove the Global.asax from this web application as it is not the host. Being able to have the normal tooling experience we’ve come to expect from Visual Studio makes creating portable areas quite simple. This even allows us to do things like creating a project template such as “MVC Portable Area Web Application” that would come pre-configured with routes set up in the PortableAreaRegistration and no Global.asax file.

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  • Surface development: it&rsquo;s just like software development

    - by Dennis Vroegop
    Surface is magic. Everyone using it seems to think that way. And I have to be honest, after working for almost 2 years with the platform I still get that special feeling the moment I turn on the unit to do some more work. The whole user experience, the rich environment of the SDK, the touch, even the look and feel of the Surface environment is so much different from the stuff I’ve been working on all my career that I am still bewildered by it. But… and this is a big but.. in the end we’re still talking about a computer and that needs software to become useful. Deep down the magic of the Surface unit there is a PC somewhere, running Windows Vista and the .net framework 3.5. When you write that magic software that makes the platform come alive you’re still working with .net, WPF/XNA, C#, VB.Net and all those other tools and technologies you know so well. Sure, the whole user experience is different from what you’ve known. And the way of thinking about users, their interaction and the positioning of screen elements requires a whole new paradigm. And that takes time. It took me about half a year before I had the feeling I got it nailed down. But when that moment came (about 18 months ago…) I realized that everything I had learned so far on software development still is true when it comes to Surface. The last 6 months I have been working with some people with a different background to start a new company. The idea was that the new company would be focussing on Surface and Surface only. These people come from a marketing background and had some good ideas for some applications. And I have to admit: their ideas were good. Very good. Where it all fell down of course is that these ideas need to be implemented in a piece of software. And creating great software takes skilled developers and a lot of time and money. That’s where things went wrong: the marketing guys didn’t realize and didn’t want to realize that software development is a job that takes skill. You can’t just hire a bunch of developers and expect them to deliver the best sort of software, especially not when it comes to Surface. I tried to explain that yes, their User Interface in Photoshop looked great, but no: I couldn’t develop an application like that in a weeks time. Even worse: the while backend of the software (WCF for communications, SQL Server for the database, etc) would take a lot more time than the frontend. They didn’t understand. It took them a couple of days to drawn the UI in Photoshop so in Blend I should be able to build the software in about the same amount of time. Well, you and I know that it doesn’t work that way. Software is hard to write, and even harder to write well, and it takes skill and dedication. It’s not something you can do as fast as you can draw a mock up for a Surface application in Photohop. The same holds true for web applications of course. A lot of designers there fail to appreciate the hard work that goes into writing the plumbing for a good web app that can handle thousands of users. Although the UI is very important, it’s not all there is to it. And in Surface development this is the same. The UI should create the feeling of magic, but the software behind it is what makes it come alive. And that takes time. A lot of time. So brush of you skills and don’t throw them away if you start developing for Surface. Because projects (and colaborations) can fail there as hard as they can in any other area of software development. On a side note: we decided to stop the colaboration (something the other parties involved didn’t appreciate and were very angry about) and decided to hire a designer for the Surface projects. The focus is back where it belongs: on the software development we know so well and have been doing very well for 13 years. UI is just a part of the whole project and not the end product. So my company Detrio is still going strong when it comes to develivering Surface solutions but once again from a technological background, not a marketing background.

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  • Book Review &ndash; Developer&rsquo;s Guide To Collections in Microsoft&reg; .NET

    - by Lori Lalonde
    Developer’s Guide To Collections in Microsoft® .NET, by Calvin Janes, discusses the various collections available in the built-in NET libraries, as well as  the advantages and disadvantages of using each type of collection. Other areas are also covered including how collections utilize memory, how to use LINQ with collections, using threading with collections, serializing collections, and how to bind collections to controls in Windows Forms, WPF and Silverlight. For developers looking for a simple reference book on collections, then this book will serve that purpose and serve it well. For those looking for a great read from cover-to-cover, they may be disappointed. This book tends to be repetitive in discussion topics, examples, and code samples in the first two parts of the book. In the first part, the author conducts walk-throughs to develop custom collections. In  the second part, the author conducts walk-throughs on using the built-in .NET collections. For experienced .NET developers, the first two parts will not provide much value. However, it is beneficial for new developers who have not worked with the built-in collections in .NET. They will obtain an understanding of the mechanics of the built-in collections and how memory is utilized when using the various types of collections. So in this aspect, new developers will get more value out of this book. The third and fourth parts delve into advanced topics, including using LINQ, threading, serialization and data binding. I find these two parts of the book are well written and flow better than the first two parts. Both beginner and experienced developers will find value in this half of the book, mainly on the topics of threading and serialization. The eBook format of this book was provided free through O'Reilly's Blogger Review program. This book can be purchased from the O'Reilly book store at: http://shop.oreilly.com/product/0790145317193.do

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  • Messing with the Team

    - by Robert May
    Good Product Owners will help the team be the best that they can be.  Bad product owners will mess with the team and won’t care about the team.  If you’re a product owner, seek to do good and avoid bad behavior at all costs.  Remember, this is for YOUR benefit and you have much power given to you.  Use that power wisely. Scope Creep The product owner has several tools at his disposal to inject scope into an iteration.  First, the product owner can use defects to inject scope.  To do this, they’ll tell the team what functionality that they want to see in a feature.  Then, after the feature is developed, the Product Owner will decide that they don’t really like how the functionality behaves.  To change it, rather than creating a new story, they’ll add a defect.  The functionality is correct, as designed, but the Product Owner doesn’t like it.  By creating the defect, the Product Owner destroys the trust that the team has of the product owner.  They may not be able to count the story, because the Product Owner changed the story in the iteration, and the team then ends up looking like they have low velocity for something over which they have no control.  This is bad.  One way to deal with this is to add “Product Owner Time” to the iteration.  This will slow the velocity, but then the ScrumMaster can tell stake holders that this time is strictly in place to deal with bad behavior of the Product Owner. Another mechanism often used to inject Scope is the concept of directed development.  Outside of planning, stand-ups, or any other meeting, the Product Owner will take a developer aside and ask them to complete a task for them.  This is bad!  The team should be allocating all of their time to development.  If the Product Owner asks for a favor, then time that would normally be used for development will be used for a pet project of the Product Owner and the team will not get credit for this work.  Selfish product owners do this, and I typically see people who were “managers” do this behavior.  Authoritarian command and control development environments also see this happen.  The best thing that can happen is for the team member to report the issue to the ScrumMaster and the ScrumMaster to get very aggressive with management and the Product Owner to try and stop the behavior.  This may result in the ScrumMaster being fired, but if the behavior continues, Scrum is doomed.  This problem is especially bad in cases where the team member’s direct supervisor is the Product Owner.  I don’t recommend that the Product Owner or ScrumMaster have a direct report relationship with team members, since team members need the ability to say no.  To work around this issue, team members need to say no.  If that fails, team members need to add extra time to the iteration to deal with the scope creep injection and accept the lower velocity. As discussed above, another mechanism for injecting scope is by changing acceptance tests after the work is complete.  This is similar to adding defects to change scope and is bad.  To get around, add time for Product Owner uncertainty to the iteration and make sure that stakeholders are aware of the need to add this time because of the Product Owner. Refusing to Prioritize Refusing to prioritize causes chaos for the team.  From the team’s perspective, things that are not important will be worked on while things that the team knows are vital will be ignored.  A poor Product Owner will often pick the stories for the iteration on a whim.  This leads to the team working on many different aspects of the product and results in a lower velocity, since each iteration the team must switch context to the new area of development. The team will also experience confusion about priorities.  In one iteration, Feature X was the highest priority and had to be done.  Then, the following iteration, even though parts of Feature X still need to be completed, no stories to address them will be in the iteration.  However, three iterations later, Feature X will again become high priority. This will cause the team to not trust the Product Owner, and eventually, they’ll stop caring about the features they implement.  They won’t know what is important, so to insulate themselves from the ever changing chaos, they’ll become apathetic to all features.  Team members are some of the most creative people in a company.  By losing their engagement, the company is going to have a substandard product because the passion for the product won’t be in the team. Other signs that the Product Owner refuses to prioritize is that no one outside of the product owner will be consulted on priorities.  Additionally, the product, release, and iteration backlogs will be weak or non-existent. Dealing with this issue is not easy.  This really isn’t something the team can fix, short of taking over the role of Product Owner themselves.  An appeal to the stake holders might work, but only if the Product Owner isn’t a “manager” themselves.  The ScrumMaster needs to protect the team and do what they can to either get the Product Owner to prioritize or have the Product Owner replaced. Managing the Team A Product Owner that is also the “boss” of team members is a Scrum team that is waiting to fail.  If your boss tells you to do something, failing to do that something can cause you to be fired.  The team needs the ability to tell the Product Owner NO.  If the product owner introduces scope creep, the team has a responsibility to tell the Product Owner no.  If the Product Owner tries to get the team to commit to more than they can accomplish in an iteration, the team needs the ability to tell the Product Owner no. If the Product Owner is your boss and determines your pay increases, you’re probably not going to ever tell them no, and Scrum will likely fail.  The team can’t do much in this situation. Another aspect of “managing the team” that often happens is the Product Owner tries to tell the team how to develop the stories that are in the iteration.  This is one reason why I recommend that Product Owners are NOT technical people.  That way, the team can come up with the tasks that are needed to accomplish the stories and the Product Owner won’t know better.  If the Product Owner is technical, the ScrumMaster will need to take great care to protect the team from the ScrumMaster changing how the team thinks they need to implement the stories. Product Owners can also try to manage the team by their body language.  If the team says a task is going to take 6 hours to complete, and the Product Owner disagrees, they will use some kind of sour body language to indicate this disagreement.  In weak teams, this may cause the team to revise their estimate down, which will result in them taking longer than estimated and may result in them missing the iteration.  The ScrumMaster will need to make sure that the Product Owner doesn’t send such messages and that the team ignores them and estimates what they REALLY think it will take to complete the tasks.  Forcing the team to deal with such items in the retrospective can be helpful. Absenteeism The team is completely dependent upon the Product Owner to develop features for the customer.  The Product Owner IS the voice of the customer and without them, the team will lack direction.  Being the Product Owner is a full time job!  If the Product Owner cannot dedicate daily time with the team, a different product owner should be found. The Product Owner needs to attend every stand-up, planning meeting, showcase, and retrospective that the team has.  The team also must be able to have instant communication with the product owner.  They must not be required to schedule meetings to speak with their product owner.  The team must be the highest priority task that the Product Owner has. The best way to work around an absent Product Owner is to appoint a new Product Owner in the team.  This person will be responsible for making the decisions that the Product Owner should be making and to act as the liaison to the absent Product Owner.  If the delegate Product Owner doesn’t have authority to make decisions for the team, Scrum will fail.  If the Product Owner is absent, the ScrumMaster should seek to have that Product Owner replaced by someone who has the time and ability to be a real Product Owner. Making it Personal Too often Product Owners will become convinced that their ideas are the ones that matter and that anyone who disagrees is making a personal attack on them.  Remember that Product Owners will inherently be at odds with many people, simply because they have the need to prioritize.  Others will frequently question prioritization because they only see part of the picture that Product Owners face. Product Owners must have a thick skin and think egos.  If they don’t, they tend to make things personal, which causes them to become emotional and causes them to take actions that can destroy the trust that team members have in the Product Owner. If a Product Owner is making things person, the best thing that team members can do is reassure them that its not personal, but be firm about doing what is best for the Company and for the users.  The ScrumMaster should also spend significant time coaching the Product Owner on how to not react emotionally and how to accept criticism without becoming defensive. Conclusion I’m sure there are other ways that a Product Owner can mess with the team, but these are the most common that I’ve seen.  I would encourage all Product Owners to seek to be a good Product Owner.  If you find yourself behaving in any of the bad product owner ways, change your behavior today!  Your team will thank you. Remember, being Product Owner is very difficult!  Product Owner is one of the most difficult roles in Scrum.  However, it can also be one of the most rewarding roles in Scrum, since Product Owners literally see their ideas brought to life on the computer screen.  Product Owners need to be very patient, even in the face of criticism and need to be willing to make tough decisions on priority, but then not become offended when others disagree with those decisions.  Companies should spend the time needed to find the right product owners for their teams.  Doing so will only help the company to write better software. Technorati Tags: Scrum,Product Owner

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  • Communication Between Your PC and Azure VM via Windows Azure Connect

    - by Shaun
    With the new release of the Windows Azure platform there are a lot of new features available. In my previous post I introduced a little bit about one of them, the remote desktop access to azure virtual machine. Now I would like to talk about another cool stuff – Windows Azure Connect.   What’s Windows Azure Connect I would like to quote the definition of the Windows Azure Connect in MSDN With Windows Azure Connect, you can use a simple user interface to configure IP-sec protected connections between computers or virtual machines (VMs) in your organization’s network, and roles running in Windows Azure. IP-sec protects communications over Internet Protocol (IP) networks through the use of cryptographic security services. There’s an image available at the MSDN as well that I would like to forward here As we can see, using the Windows Azure Connect the Worker Role 1 and Web Role 1 are connected with the development machines and database servers which some of them are inside the organization some are not. With the Windows Azure Connect, the roles deployed on the cloud could consume the resource which located inside our Intranet or anywhere in the world. That means the roles can connect to the local database, access the local shared resource such as share files, folders and printers, etc.   Difference between Windows Azure Connect and AppFabric It seems that the Windows Azure Connect are duplicated with the Windows Azure AppFabric. Both of them are aiming to solve the problem on how to communication between the resource in the cloud and inside the local network. The table below lists the differences in my understanding. Category Windows Azure Connect Windows Azure AppFabric Purpose An IP-sec connection between the local machines and azure roles. An application service running on the cloud. Connectivity IP-sec, Domain-joint Net Tcp, Http, Https Components Windows Azure Connect Driver Service Bus, Access Control, Caching Usage Azure roles connect to local database server Azure roles use local shared files,  folders and printers, etc. Azure roles join the local AD. Expose the local service to Internet. Move the authorization process to the cloud. Integrate with existing identities such as Live ID, Google ID, etc. with existing local services. Utilize the distributed cache.   And also some scenarios on which of them should be used. Scenario Connect AppFabric I have a service deployed in the Intranet and I want the people can use it from the Internet.   Y I have a website deployed on Azure and need to use a database which deployed inside the company. And I don’t want to expose the database to the Internet. Y   I have a service deployed in the Intranet and is using AD authorization. I have a website deployed on Azure which needs to use this service. Y   I have a service deployed in the Intranet and some people on the Internet can use it but need to be authorized and authenticated.   Y I have a service in Intranet, and a website deployed on Azure. This service can be used from Internet and that website should be able to use it as well by AD authorization for more functionalities. Y Y   How to Enable Windows Azure Connect OK we talked a lot information about the Windows Azure Connect and differences with the Windows Azure AppFabric. Now let’s see how to enable and use the Windows Azure Connect. First of all, since this feature is in CTP stage we should apply before use it. On the Windows Azure Portal we can see our CTP features status under Home, Beta Program page. You can send the apply to join the Beta Programs to Microsoft in this page. After a few days the Microsoft will send an email to you (the email of your Live ID) when it’s available. In my case we can see that the Windows Azure Connect had been activated by Microsoft and then we can click the Connect button on top, or we can click the Virtual Network item from the left navigation bar.   The first thing we need, if it’s our first time to enter the Connect page, is to enable the Windows Azure Connect. After that we can see our Windows Azure Connect information in this page.   Add a Local Machine to Azure Connect As we explained below the Windows Azure Connect can make an IP-sec connection between the local machines and azure role instances. So that we firstly add a local machine into our Azure Connect. To do this we will click the Install Local Endpoint button on top and then the portal will give us an URL. Copy this URL to the machine we want to add and it will download the software to us. This software will be installed in the local machines which we want to join the Connect. After installed there will be a tray-icon appeared to indicate this machine had been joint our Connect. The local application will be refreshed to the Windows Azure Platform every 5 minutes but we can click the Refresh button to let it retrieve the latest status at once. Currently my local machine is ready for connect and we can see my machine in the Windows Azure Portal if we switched back to the portal and selected back Activated Endpoints node.   Add a Windows Azure Role to Azure Connect Let’s create a very simple azure project with a basic ASP.NET web role inside. To make it available on Windows Azure Connect we will open the azure project property of this role from the solution explorer in the Visual Studio, and select the Virtual Network tab, check the Activate Windows Azure Connect. The next step is to get the activation token from the Windows Azure Portal. In the same page there is a button named Get Activation Token. Click this button then the portal will display the token to me. We copied this token and pasted to the box in the Visual Studio tab. Then we deployed this application to azure. After completed the deployment we can see the role instance was listed in the Windows Azure Portal - Virtual Connect section.   Establish the Connect Group The final task is to create a connect group which contains the machines and role instances need to be connected each other. This can be done in the portal very easy. The machines and instances will NOT be connected until we created the group for them. The machines and instances can be used in one or more groups. In the Virtual Connect section click the Groups and Roles node from the left side navigation bar and clicked the Create Group button on top. This will bring up a dialog to us. What we need to do is to specify a group name, description; and then we need to select the local computers and azure role instances into this group. After the Azure Fabric updated the group setting we can see the groups and the endpoints in the page. And if we switch back to the local machine we can see that the tray-icon have been changed and the status turned connected. The Windows Azure Connect will update the group information every 5 minutes. If you find the status was still in Disconnected please right-click the tray-icon and select the Refresh menu to retrieve the latest group policy to make it connected.   Test the Azure Connect between the Local Machine and the Azure Role Instance Now our local machine and azure role instance had been connected. This means each of them can communication to others in IP level. For example we can open the SQL Server port so that our azure role can connect to it by using the machine name or the IP address. The Windows Azure Connect uses IPv6 to connect between the local machines and role instances. You can get the IP address from the Windows Azure Portal Virtual Network section when select an endpoint. I don’t want to take a full example for how to use the Connect but would like to have two very simple tests. The first one would be PING.   When a local machine and role instance are connected through the Windows Azure Connect we can PING any of them if we opened the ICMP protocol in the Filewall setting. To do this we need to run a command line before test. Open the command window on the local machine and the role instance, execute the command as following netsh advfirewall firewall add rule name="ICMPv6" dir=in action=allow enable=yes protocol=icmpv6 Thanks to Jason Chen, Patriek van Dorp, Anton Staykov and Steve Marx, they helped me to enable  the ICMPv6 setting. For the full discussion we made please visit here. You can use the Remote Desktop Access feature to logon the azure role instance. Please refer my previous blog post to get to know how to use the Remote Desktop Access in Windows Azure. Then we can PING the machine or the role instance by specifying its name. Below is the screen I PING my local machine from my azure instance. We can use the IPv6 address to PING each other as well. Like the image following I PING to my role instance from my local machine thought the IPv6 address.   Another example I would like to demonstrate here is folder sharing. I shared a folder in my local machine and then if we logged on the role instance we can see the folder content from the file explorer window.   Summary In this blog post I introduced about another new feature – Windows Azure Connect. With this feature our local resources and role instances (virtual machines) can be connected to each other. In this way we can make our azure application using our local stuff such as database servers, printers, etc. without expose them to Internet.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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  • Adding Volcanos and Options - Earthquake Locator, part 2

    - by Bobby Diaz
    Since volcanos are often associated with earthquakes, and vice versa, I decided to show recent volcanic activity on the Earthquake Locator map.  I am pulling the data from a website created for a joint project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program, found here.  They provide a Weekly Volcanic Activity Report as an RSS feed.   I started implementing this new functionality by creating a new Volcano entity in the domain model and adding the following to the EarthquakeService class (I also factored out the common reading/parsing helper methods to a separate FeedReader class that can be used by multiple domain service classes):           private static readonly string VolcanoFeedUrl =             ConfigurationManager.AppSettings["VolcanoFeedUrl"];           /// <summary>         /// Gets the volcano data for the previous week.         /// </summary>         /// <returns>A queryable collection of <see cref="Volcano"/> objects.</returns>         public IQueryable<Volcano> GetVolcanos()         {             var feed = FeedReader.Load(VolcanoFeedUrl);             var list = new List<Volcano>();               if ( feed != null )             {                 foreach ( var item in feed.Items )                 {                     var quake = CreateVolcano(item);                     if ( quake != null )                     {                         list.Add(quake);                     }                 }             }               return list.AsQueryable();         }           /// <summary>         /// Creates a <see cref="Volcano"/> object for each item in the RSS feed.         /// </summary>         /// <param name="item">The RSS item.</param>         /// <returns></returns>         private Volcano CreateVolcano(SyndicationItem item)         {             Volcano volcano = null;             string title = item.Title.Text;             string desc = item.Summary.Text;             double? latitude = null;             double? longitude = null;               FeedReader.GetGeoRssPoint(item, out latitude, out longitude);               if ( !String.IsNullOrEmpty(title) )             {                 title = title.Substring(0, title.IndexOf('-'));             }             if ( !String.IsNullOrEmpty(desc) )             {                 desc = String.Join("\n\n", desc                         .Replace("<p>", "")                         .Split(                             new string[] { "</p>" },                             StringSplitOptions.RemoveEmptyEntries)                         .Select(s => s.Trim())                         .ToArray())                         .Trim();             }               if ( latitude != null && longitude != null )             {                 volcano = new Volcano()                 {                     Id = item.Id,                     Title = title,                     Description = desc,                     Url = item.Links.Select(l => l.Uri.OriginalString).FirstOrDefault(),                     Latitude = latitude.GetValueOrDefault(),                     Longitude = longitude.GetValueOrDefault()                 };             }               return volcano;         } I then added the corresponding LoadVolcanos() method and Volcanos collection to the EarthquakeViewModel class in much the same way I did with the Earthquakes in my previous article in this series. Now that I am starting to add more information to the map, I wanted to give the user some options as to what is displayed and allowing them to choose what gets turned off.  I have updated the MainPage.xaml to look like this:   <UserControl x:Class="EarthquakeLocator.MainPage"     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"     xmlns:basic="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls"     xmlns:bing="clr-namespace:Microsoft.Maps.MapControl;assembly=Microsoft.Maps.MapControl"     xmlns:vm="clr-namespace:EarthquakeLocator.ViewModel"     mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480" >     <UserControl.Resources>         <DataTemplate x:Key="EarthquakeTemplate">             <Ellipse Fill="Red" Stroke="Black" StrokeThickness="1"                      Width="{Binding Size}" Height="{Binding Size}"                      bing:MapLayer.Position="{Binding Location}"                      bing:MapLayer.PositionOrigin="Center">                 <ToolTipService.ToolTip>                     <StackPanel>                         <TextBlock Text="{Binding Title}" FontSize="14" FontWeight="Bold" />                         <TextBlock Text="{Binding UtcTime}" />                         <TextBlock Text="{Binding LocalTime}" />                         <TextBlock Text="{Binding DepthDesc}" />                     </StackPanel>                 </ToolTipService.ToolTip>             </Ellipse>         </DataTemplate>           <DataTemplate x:Key="VolcanoTemplate">             <Polygon Fill="Gold" Stroke="Black" StrokeThickness="1" Points="0,10 5,0 10,10"                      bing:MapLayer.Position="{Binding Location}"                      bing:MapLayer.PositionOrigin="Center"                      MouseLeftButtonUp="Volcano_MouseLeftButtonUp">                 <ToolTipService.ToolTip>                     <StackPanel>                         <TextBlock Text="{Binding Title}" FontSize="14" FontWeight="Bold" />                         <TextBlock Text="Click icon for more information..." />                     </StackPanel>                 </ToolTipService.ToolTip>             </Polygon>         </DataTemplate>     </UserControl.Resources>       <UserControl.DataContext>         <vm:EarthquakeViewModel AutoLoadData="True" />     </UserControl.DataContext>       <Grid x:Name="LayoutRoot">           <bing:Map x:Name="map" CredentialsProvider="--Your-Bing-Maps-Key--"                   Center="{Binding MapCenter, Mode=TwoWay}"                   ZoomLevel="{Binding ZoomLevel, Mode=TwoWay}">               <bing:MapItemsControl ItemsSource="{Binding Earthquakes}"                                   ItemTemplate="{StaticResource EarthquakeTemplate}" />               <bing:MapItemsControl ItemsSource="{Binding Volcanos}"                                   ItemTemplate="{StaticResource VolcanoTemplate}" />         </bing:Map>           <basic:TabControl x:Name="tabs" VerticalAlignment="Bottom" MaxHeight="25" Opacity="0.7">             <basic:TabItem Margin="90,0,-90,0" MouseLeftButtonUp="TabItem_MouseLeftButtonUp">                 <basic:TabItem.Header>                     <TextBlock x:Name="txtHeader" Text="Options"                                FontSize="13" FontWeight="Bold" />                 </basic:TabItem.Header>                   <StackPanel Orientation="Horizontal">                     <TextBlock Text="Earthquakes:" FontWeight="Bold" Margin="3" />                     <StackPanel Margin="3">                         <CheckBox Content=" &lt; 4.0"                                   IsChecked="{Binding ShowLt4, Mode=TwoWay}" />                         <CheckBox Content="4.0 - 4.9"                                   IsChecked="{Binding Show4s, Mode=TwoWay}" />                         <CheckBox Content="5.0 - 5.9"                                   IsChecked="{Binding Show5s, Mode=TwoWay}" />                     </StackPanel>                       <StackPanel Margin="10,3,3,3">                         <CheckBox Content="6.0 - 6.9"                                   IsChecked="{Binding Show6s, Mode=TwoWay}" />                         <CheckBox Content="7.0 - 7.9"                                   IsChecked="{Binding Show7s, Mode=TwoWay}" />                         <CheckBox Content="8.0 +"                                   IsChecked="{Binding ShowGe8, Mode=TwoWay}" />                     </StackPanel>                       <TextBlock Text="Other:" FontWeight="Bold" Margin="50,3,3,3" />                     <StackPanel Margin="3">                         <CheckBox Content="Volcanos"                                   IsChecked="{Binding ShowVolcanos, Mode=TwoWay}" />                     </StackPanel>                 </StackPanel>               </basic:TabItem>         </basic:TabControl>       </Grid> </UserControl> Notice that I added a VolcanoTemplate that uses a triangle-shaped Polygon to represent the Volcano locations, and I also added a second <bing:MapItemsControl /> tag to the map to bind to the Volcanos collection.  The TabControl found below the map houses the options panel that will present the user with several checkboxes so they can filter the different points based on type and other properties (i.e. Magnitude).  Initially, the TabItem is collapsed to reduce it's footprint, but the screen shot below shows the options panel expanded to reveal the available settings:     I have updated the Source Code and Live Demo to include these new features.   Happy Mapping!

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  • Error: The base type 'System.Web.UI.MasterPage' is not allowed for this page

    - by Patrick Olurotimi Ige
    I came across this error when i was trying to ajaxify my sharepoint site. After adding the AjaxifyMoss from the codeplex  developed by Richard Finn. And tried loading my site i got the error Error: The base type 'System.Web.UI.MasterPage' is not allowed for this page So  i decided to check the web.config and i noticed the SafeControl tag doesn't have the .Net 2.0 assembly included despite the fact i added both vsersios 2.0 and 3.5. Its possible the.Net  3.5 assebply overwrote the 2.0. Anyway after i added the below which is the 2.0 verison       <SafeControl Assembly="System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" Namespace="System.Web.UI" TypeName="*" Safe="True" AllowRemoteDesigner="True" />  And refreshed my page. It worked

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  • Silverlight Cream for April 01, 2010 -- #827

    - by Dave Campbell
    In this Issue: Max Paulousky, Hassan, Viktor Larsson, Fons Sonnemans, Jim McCurdy, Scott Marlowe, Mike Taulty, Brad Abrams, Jesse Liberty, Scott Barnes, Christopher Bennage, and John Papa and Ward Bell. Shoutouts: Tim Heuer posted a survey: What tools are the minimum to get started in Silverlight?... have you responded yet? Don't want to miss this discussion: Channel 9 Live at MIX10: Bill Buxton & Erik Meijer - Perspectives on Design Bookmark this... Jesse Liberty has moved his site: Silverlight Geek I stand with Tim Heuer on this: Congratulations to latest 2nd quarter Silverlight MVPs From SilverlightCream.com: Wizards. Prototype of sketching Wizard for WPF - 1 Max Paulousky is creating a SketchFlow WPF wizard in Expression Blend... looks like good Expression Blend and SketchFlow no matter what the target is Windows Phone 7 Navigation Hassan has another WP7 Video up, and this one is on Navigation and passing data from page to page. Silverlight 4 PathListBox Viktor Larsson is blogging about the PathListBox, and definitely had a good time doing so.. lots of fun examples. CountDown Clock in Silverlight 4 Fons Sonnemans has reworked his Sivlerlight 3 FlipClock to be this Silverlight 4 CountDown Clock utilizing the Viewbox control to make it scalable. Generic class for deep clone of Silverlight and CLR objects Jim McCurdy has a Silverlight 3 and 4-tested CloneObject class that he's using for creating a deep copy of an object and all it's properties... think drag/drop or undo/redo. Animating the Fill Color of a Silverlight Ellipse Scott Marlowe has a tutorial up that animates a pass/fail indicator with a smooth transition from a red to a green state... all with code. Silverlight 4, Blend 4, MVVM, Binding, DependencyObject Mike Taulty has a great tutorial up on Blend4 and binding... he's got a somewhat contrived example going, but it certainly looks good to me :) Silverlight 4 + RIA Services - Ready for Business: Authentication and Personalization Next up in Brad Abrams' series is Authentication and Personalization. RIA Services makes this easy to do... let Brad show you! An Annotated Line of Business Application Jesse Liberty is walking through the design and delivery of his HyperVideo project with this mini tutorial. Want to understand the thought process behind the LOB app, check this out. How to hack Expression Blend Seems like there was just some discussion about some of this today and here Scott Barnes posts this hack job for Expression Blend... pretty cool actually :) d:DesignInstance in Blend 4 Christopher Bennage has a follow-on post about using d:DesignInstance in Blend 4, and this is a very nice tutorial on the subject Silverlight TV 19: Hidden Gems from MIX10, UFC's Multi-Touch App John Papa and Ward Bell front and center for Silverlight TV number 19... and check out those threads! Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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  • One National Team One Event &ndash; SharePoint Saturday Kansas City

    - by MOSSLover
    I wasn’t expect to run an event from 1,000 miles away, but some stuff happened you know like it does and I opted in.  It was really weird, because people asked why are you living in NJ and running Kansas City?  I did move, but it was like my baby and Karthik didn’t have the ability to do it this year.  I found it really challenging, because I could not physically be in Kansas City.  At first I was freaking out and Lee Brandt, Brian Laird, and Chris Geier offered to help.  Somehow I couldn’t come the day of the event.  Time-wise it just didn’t work out.  I could do all the leg work prior to the event, but weekends just were not good.  I was going to be in DC until March or April on the weekdays, so leaving that weekend was too tough.  As it worked out Lee was my eyes and ears for the venue.  Brian was the sponsor and prize box coordinator if anyone needed to send items.  Lee also helped Brian the day of the event move all the boxes.  I did everything we could do electronically, such as get the sponsors coordinate with Michael Lotter on invoicing and getting the speakers, posting the submissions, budgeting the money, setting up a speaker dinner by phone, plus all that other stuff you do behind the scenes.  Chris was there to help Lee and Brian the day of the event and help us out with the speaker dinner.  Karthik finally got back from India and he was there the night before getting the folders together and the signs and stuffing it all.  Jason Gallicchio also helped me out (my cohort for SPS NYC) as he did the schedule and helped with posting the speakers abstracts and so did Chris Geier by posting the bios.  The lot of them enlisted a few other monkeys to help out.  It was the weirdest thing I’ve ever seen, but it worked.  Around 100+ attendees ended up showing and I hear it was  a great event.  Jason, Michael, Chris, Karthik, Brian, and Lee are not all from the same area, but they helped me out in bringing this event together.  It was a national SharePoint Saturday team that brought together a specific local event for Kansas City.  It’s like a metaphor for the entire SharePoint Community.  We help our own kind out we don’t let me fail.  I know Lee and Brian aren’t technically SharePoint People they are honorary SharePoint Community Members.  Thanks everyone for the support and help in bringing this event together.  Technorati Tags: SharePoint Saturday,SPS KC,SharePoint,SharePoint Saturday Kanas City,Kansas City

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  • Firefox for NTLM secured sites

    - by Sarang
    Spent the last weekend fighting to get firefox to connect to a sharepoint portal hosting my homegrown TFS instance's TFS/WEB and team project portal from a friends' place. Firefox is THE favourite browser and I was hating to se it fail miserably with NTLM authentication. Fun part is it showed the login prompt accepted credentials and like a pestering young puppy came back for the same credentials. After banging my head and various "I don't know what I don't know" attempts I decided to play god and entered the firefox's advance config mode. And voila! there sits a nifty little option called network.automatic-ntlm-auth.trusted-uris. Assign your URI to it and you are through. No more shameface before those Chrome/Opera users. :). To enter FireFox's god mode, open a new tab and type about:config in the address bar. There is a search box which certainly comes handy shifting through hundreds of options. The root lies in firefox's default mechanism of not allowing NTLM passthrough authentication. Firefox defaults to digest credentials which are blatantly refused by a web app expecting NTLM which results in authentication failure and Firefox keeps asking for credentials over and over again. The steps listed above are same as adding a website to your trusted sites' list in Internet Explorer.

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  • GuestPost: Unit Testing Entity Framework (v1) Dependent Code using TypeMock Isolator

    - by Eric Nelson
    Time for another guest post (check out others in the series), this time bringing together the world of mocking with the world of Entity Framework. A big thanks to Moses for agreeing to do this. Unit Testing Entity Framework Dependent Code using TypeMock Isolator by Muhammad Mosa Introduction Unit testing data access code in my opinion is a challenging thing. Let us consider unit tests and integration tests. In integration tests you are allowed to have environmental dependencies such as a physical database connection to insert, update, delete or retrieve your data. However when performing unit tests it is often much more efficient and productive to remove environmental dependencies. Instead you will need to fake these dependencies. Faking a database (also known as mocking) can be relatively straight forward but the version of Entity Framework released with .Net 3.5 SP1 has a number of implementation specifics which actually makes faking the existence of a database quite difficult. Faking Entity Framework As mentioned earlier, to effectively unit test you will need to fake/simulate Entity Framework calls to the database. There are many free open source mocking frameworks that can help you achieve this but it will require additional effort to overcome & workaround a number of limitations in those frameworks. Examples of these limitations include: Not able to fake calls to non virtual methods Not able to fake sealed classes Not able to fake LINQ to Entities queries (replace database calls with in-memory collection calls) There is a mocking framework which is flexible enough to handle limitations such as those above. The commercially available TypeMock Isolator can do the job for you with less code and ultimately more readable unit tests. I’m going to demonstrate tackling one of those limitations using MoQ as my mocking framework. Then I will tackle the same issue using TypeMock Isolator. Mocking Entity Framework with MoQ One basic need when faking Entity Framework is to fake the ObjectContext. This cannot be done by passing any connection string. You have to pass a correct Entity Framework connection string that specifies CSDL, SSDL and MSL locations along with a provider connection string. Assuming we are going to do that, we’ll explore another limitation. The limitation we are going to face now is related to not being able to fake calls to non-virtual/overridable members with MoQ. I have the following repository method that adds an EntityObject (instance of a Blog entity) to Blogs entity set in an ObjectContext. public override void Add(Blog blog) { if(BlogContext.Blogs.Any(b=>b.Name == blog.Name)) { throw new InvalidOperationException("Blog with same name already exists!"); } BlogContext.AddToBlogs(blog); } The method does a very simple check that the name of the new Blog entity instance doesn’t exist. This is done through the simple LINQ query above. If the blog doesn’t already exist it simply adds it to the current context to be saved when SaveChanges of the ObjectContext instance (e.g. BlogContext) is called. However, if a blog with the same name exits, and exception (InvalideOperationException) will be thrown. Let us now create a unit test for the Add method using MoQ. [TestMethod] [ExpectedException(typeof(InvalidOperationException))] public void Add_Should_Throw_InvalidOperationException_When_Blog_With_Same_Name_Already_Exits() { //(1) We shouldn't depend on configuration when doing unit tests! But, //its a workaround to fake the ObjectContext string connectionString = ConfigurationManager .ConnectionStrings["MyBlogConnString"] .ConnectionString; //(2) Arrange: Fake ObjectContext var fakeContext = new Mock<MyBlogContext>(connectionString); //(3) Next Line will pass, as ObjectContext now can be faked with proper connection string var repo = new BlogRepository(fakeContext.Object); //(4) Create fake ObjectQuery<Blog>. Will be used to substitute MyBlogContext.Blogs property var fakeObjectQuery = new Mock<ObjectQuery<Blog>>("[Blogs]", fakeContext.Object); //(5) Arrange: Set Expectations //Next line will throw an exception by MoQ: //System.ArgumentException: Invalid setup on a non-overridable member fakeContext.SetupGet(c=>c.Blogs).Returns(fakeObjectQuery.Object); fakeObjectQuery.Setup(q => q.Any(b => b.Name == "NewBlog")).Returns(true); //Act repo.Add(new Blog { Name = "NewBlog" }); } This test method is checking to see if the correct exception ([ExpectedException(typeof(InvalidOperationException))]) is thrown when a developer attempts to Add a blog with a name that’s already exists. On (1) a connection string is initialized from configuration file. To retrieve the full connection string. On (2) a fake ObjectContext is being created. The ObjectContext here is MyBlogContext and its being created using this var fakeContext = new Mock<MyBlogContext>(connectionString); This way a fake context is being created using MoQ. On (3) a BlogRepository instance is created. BlogRepository has dependency on generate Entity Framework ObjectContext, MyObjectContext. And so the fake context is passed to the constructor. var repo = new BlogRepository(fakeContext.Object); On (4) a fake instance of ObjectQuery<Blog> is being created to use as a substitute to MyObjectContext.Blogs property as we will see in (5). On (5) setup an expectation for calling Blogs property of MyBlogContext and substitute the return result with the fake ObjectQuery<Blog> instance created on (4). When you run this test it will fail with MoQ throwing an exception because of this line: fakeContext.SetupGet(c=>c.Blogs).Returns(fakeObjectQuery.Object); This happens because the generate property MyBlogContext.Blogs is not virtual/overridable. And assuming it is virtual or you managed to make it virtual it will fail at the following line throwing the same exception: fakeObjectQuery.Setup(q => q.Any(b => b.Name == "NewBlog")).Returns(true); This time the test will fail because the Any extension method is not virtual/overridable. You won’t be able to replace ObjectQuery<Blog> with fake in memory collection to test your LINQ to Entities queries. Now lets see how replacing MoQ with TypeMock Isolator can help. Mocking Entity Framework with TypeMock Isolator The following is the same test method we had above for MoQ but this time implemented using TypeMock Isolator: [TestMethod] [ExpectedException(typeof(InvalidOperationException))] public void Add_New_Blog_That_Already_Exists_Should_Throw_InvalidOperationException() { //(1) Create fake in memory collection of blogs var fakeInMemoryBlogs = new List<Blog> {new Blog {Name = "FakeBlog"}}; //(2) create fake context var fakeContext = Isolate.Fake.Instance<MyBlogContext>(); //(3) Setup expected call to MyBlogContext.Blogs property through the fake context Isolate.WhenCalled(() => fakeContext.Blogs) .WillReturnCollectionValuesOf(fakeInMemoryBlogs.AsQueryable()); //(4) Create new blog with a name that already exits in the fake in memory collection in (1) var blog = new Blog {Name = "FakeBlog"}; //(5) Instantiate instance of BlogRepository (Class under test) var repo = new BlogRepository(fakeContext); //(6) Acting by adding the newly created blog () repo.Add(blog); } When running the above test method it will pass as the Add method of BlogRepository is going to throw an InvalidOperationException which is the expected behaviour. Nothing prevents us from faking out the database interaction! Even faking ObjectContext  at (2) didn’t require a connection string. On (3) Isolator sets up a faking result for MyBlogContext.Blogs when its being called through the fake instance fakeContext created on (2). The faking result is just an in-memory collection declared an initialized on (1). Finally at (6) action we call the Add method of BlogRepository passing a new Blog instance that has a name that’s already exists in the fake in-memory collection which we set up at (1). As expected the test will pass because it will throw the expected exception defined on top of the test method - InvalidOperationException. TypeMock Isolator succeeded in faking Entity Framework with ease. Conclusion We explored how to write a simple unit test using TypeMock Isolator for code which is using Entity Framework. We also explored a few of the limitations of other mocking frameworks which TypeMock is successfully able to handle. There are workarounds that you can use to overcome limitations when using MoQ or Rhino Mock, however the workarounds will require you to write more code and your tests will likely be more complex. For a comparison between different mocking frameworks take a look at this document produced by TypeMock. You might also want to check out this open source project to compare mocking frameworks. I hope you enjoyed this post Muhammad Mosa http://mosesofegypt.net/ http://twitter.com/mosessaur Screencast of unit testing Entity Framework Related Links GuestPost: Introduction to Mocking GuesPost: Typemock Isolator – Much more than an Isolation framework

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  • Windows Azure Evolution &ndash; Welcome to VS2012

    - by Shaun
    When the Microsoft released the first preview version of Windows 8 and Visual Studio, many people in the community were asking if the windows azure tool is available to it. The answer was “NO”. Microsoft promised that the windows azure tool will only support the Visual Studio 2010 but when the 2012 was final released, windows azure tool should be work. But now alone with the new windows azure platform was published we got the latest Windows Azure SDK 1.7, which is compatible to the Visual Studio 2012 RC.   You can retrieve the latest version of the Windows Azure SDK through Web Platform Installer, which I think it’s the easiest and simplest way to download and install, since besides the SDK itself it also needs some other components. To download the latest windows azure SDK from Web Platform Installer, just go to the windows azure website and clicked the Develop, .NET and click the blue “install” button. Then you need to select which version of Visual Studio you want to use, Visual Studio 2010 or Visual Studio 2012 RC. After selected the current version you will download an EXE file. This file will lead you to install the Web Platform Installer 4.0 (if you haven’t installed) and the latest windows azure SDK. You can see the version name is June 2012, 1.7. Finally the WebPI will detect the dependent components you need to download and begin to install. But if you want to challenge yourself you can download the components and install them manually. The standalone installations are listed in this page with the instruction on how to install them with necessary pre-requirements.   Once you finished the installation you can open the Visual Studio 2012 RC and as usual, it need to be run as administrator. If you clicked the New Project link from the start page, navigated to Cloud category you will find that there no project template available. Is there anything wrong? So, if you changed the target framework from the default .NET 4.5 to .NET 4 you will see the azure project template. This is because, currently the windows azure instance does not support .NET 4.5. After clicked OK you will see the role creation window, which is similar as what you have seen before. But there are some new role templates in this SDK. Firstly you will have ASP.NET MVC 4 web role available, which means you can create ASP.NET MVC 4 applications for internet, intranet, mobile and WebAPI on the cloud. Then there are two new worker role templates, “Cache Worker Role” and “Worker Role with Service Bus Queue”. “Worker Role with Service Bus Queue” is a worker role which had added necessary references to access the Windows Azure Service Bus Queue. It also have some basic sample code in the worker role class which could read messages from the queue when started. The “Cache Worker Role” is a worker role which has the in-memory distributed cache feature enabled by default. This feature is different than the Windows Azure Caching. It allows the role instance to use its memory as a in-memory distributed cache clusters. By using this feature you can have one or more worker roles as some dedicate cache clusters. Alternatively, you can make part of your web role and worker role’s memory as the cache clusters as well. Let’s just create an ASP.NET MVC 4 Web Role, and click F5 to run it under the local emulator. If you have been working with azure for a while you should know that I need to setup the local storage emulator before running locally if it’s a fresh azure SDK installation. But in this version when we started our azure project the Visual Studio will check if the storage emulator had been initialized. If not, it will run the initializer automatically. And as you can see, in this version the storage emulator relies on the SQL Server 2012 Local DB feature. It will create the emulator database and tables in the default local database. You can set the storage emulator to use a standard SQL Server default instance by using the command “dsinit /instance:.”. The “dsinit” tool now is located at %PROGRAM FILES%\Microsoft SDKs\Windows Azure\Emulator\devstore After the Visual Studio complied and deployed the package our website should be shown in the browser. This is the MVC 4 Web Role home page on my Windows 8 machine in IE10. Another thing you might notice is that, in this version the compute emulator utilizes IIS Express to host the web roles instead of the full IIS. You can add breakpoint in the code and debug, and you can use the local storage emulator to test your code for accessing the storage service. All of them are same as what your are doing now on SDK 1.6. You can switch to use IIS to run your web role in local emulator. Just open the windows azure porject property windows, in the Web page select “Use IIS Web Server”. For more information about this please have a look on Nuno’s blog post. In the role property page in Visual Studio there’s no massive changes. You can configure your role settings such as the endpoints, certificates and local storage, etc.. One thing was added is the Caching tab. Here you can specify enable the caching feature or not, and how much memory you want to use as the cache cluster. I will introduce more details about it in the future posts. The publish and package feature are also no change. You can publish your project to azure directly through Visual Studio 2012, while you can create the package and upload manually. Below is the SDK version of my deployment which is 1.7.30602.1703 in the developer portal.   Summary In this post I introduced about the new Windows Azure SDK 1.7 especially on how it works on the latest Visual Studio 2012 RC. There’s no significant changes in the visual studio tool in this version but some small enhancement such as ASP.NET MVC 4, Cache Worker Role, using SQL 2012 Local DB and IIS Express, etc..   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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  • Comments on Comments

    - by Joe Mayo
    I almost tweeted a reply to Capar Kleijne's question about comments on Twitter, but realized that my opinion exceeded 140 characters. The following is based upon my experience with extremes and approaches that I find useful in code comments. There are a couple extremes that I've seen and reasons why people go the distance in each approach. The most common extreme is no comments in the code at all.  A few bad reasons why this happens is because a developer is in a hurry, sloppy, or is interested in job preservation. The unfortunate result is that the code is difficult to understand and hard to maintain. The drawbacks to no comments in code are a primary reason why teachers drill the need for commenting code into our heads.  This viewpoint assumes the lack of comments are bad because the code is bad, but there is another reason for not commenting that is gaining more popularity. I've heard/and read that code should be self documenting. Following this thought pattern, if code is well written with meaningful names, there should not be a reason for comments.  An addendum to this argument is that comments are often neglected and get out-of-date, but the code is what is kept up-to-date. Presumably, if code contained very good naming, it would be easy to maintain.  This is a noble perspective and I like the practice of meaningful naming of identifiers. However, I think it's also an extreme approach that doesn't cover important cases.  i.e. If an identifier is named badly (subjective differences in opinion) or not changed appropriately during maintenance, then the badly named identifier is no more useful than a stale comment. These were the two no-comment extremes, so let's look at the too many comments extreme. On a regular basis, I'll see cases where the code is over-commented; not nearly as often as the no-comment scenarios, but still prevalent.  These are examples of where every single line in the code is commented.  These comments make the code harder to read because they get in the way of the algorithm.  In most cases, the comments parrot what each line of code does.  If a developer understands the language, then most statements are immediately intuitive.  i.e. what use is it to say that I'm assigning foo to bar when it's clear what the code is doing. I think that over-commenting code is a waste of time that slows down initial development and maintenance.  Understandably, the developer's intentions are admirable because they've had it beaten into their heads that they must comment. However, I think it's an extreme and prefer a more moderate approach. I don't think the extremes do justice to code because each can make maintenance harder.  No comments on bad code is obviously a problem, but the other two extremes are subtle and require qualification to address properly. The problem I see with the code-as-documentation approach is that it doesn't lift the developer out of the algorithm to identify dependencies, intentions, and hacks. Any developer can read code and follow an algorithm, but they still need to know where it fits into the big picture of the application. Because of indirections with language features like interfaces, delegates, and virtual members, code can become complex.  Occasionally, it's useful to point out a nuance or reason why a piece of code is there. i.e. If you've building an app that communicates via HTTP, you'll have certain headers to include for the endpoint, and it could be useful to point out why the code for setting those header values is there and how they affect the application. An argument against this could be that you should extract that code into a separate method with a meaningful name to describe the scenario.  My problem with such an approach would be that your code base becomes even more difficult to navigate and work with because you have all of this extra code just to make the code more meaningful. My opinion is that a simple and well-stated comment stating the reasons and intention for the code is more natural and convenient to the initial developer and maintainer.  I just don't agree with the approach of going out of the way to avoid making a comment.  I'm also concerned that some developers would take this approach as an excuse to not comment their bad code. Another area where I like comments is on documentation comments.  Java has it and so does C# and VB.  It's convenient because we can build automated tools that extract these comments.  These extracted comments are often much better than no documentation at all.  The "go read the code" answer always doesn't fulfill the need for a quick summary of an API. To summarize, I think that the extremes of no comments and too many comments are less than desirable approaches. I prefer documentation comments to explain each class and member (API level) and code comments as necessary to supplement well-written code. Joe

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  • Rob Blackwell on interoperability and Azure

    - by Eric Nelson
    At QCon in March we had a sample Azure application implemented in both Java and Ruby to demonstrate that the Windows Azure Platform is not just about .NET. The following is an interesting interview with Rob Blackwell, the R&D director of the partner who implemented the application. UK Interoperability Team Interviews Rob Blackwell, R&D Director at Active Web Solutions. Is Microsoft taking interoperability seriously? Yes. In the past, I think Microsoft has, quite rightly come in for criticism, but architects and developers should look at this again. The Interoperability Bridges site (http://www.interoperabilitybridges.com/ ) shows a wide range of projects that allow interoperability from Java, Ruby and PHP for example. The Windows Azure platform has been architected with interoperable APIs in mind. It's straightforward to access the various storage facilities from just about any language or platform. Azure compute is capable of running more than just C# applications! Why is interoperability important to you? My company provides consultancy and bespoke development services. We're a Microsoft Gold Partner, but we live in the real world where companies have a mix of technologies provided by a variety of vendors. When developing an enterprise software solution, you rarely have a completely blank canvas. We often see integration scenarios where we need to exchange data with legacy systems. It's not unusual to see modern Silverlight applications being built on top of Java or Mainframe based back ends. Could you give us some examples of where interoperability has been important for your projects? We developed an innovative Sea Safety system for the RNLI Lifeboats here in the UK. Commercial Fishing is one of the most dangerous professions and we helped developed the MOB Guardian System which uses satellite technology and man overboard devices to raise the alarm when a fisherman gets into trouble. The solution is implemented in .NET running on Windows, but without interoperable standards, it would have been impossible to communicate with the satellite gateway technology. For more information, please see the case study: http://www.microsoft.com/casestudies/Case_Study_Detail.aspx?CaseStudyID=4000005892 More recently, we were asked to build a web site to accompany the QCon 2010 conference in London to help demonstrate and promote interoperability. We built the site using Java and Restlet and hosted it in Windows Azure Compute. The site accepts feedback from visitors and all the data is stored in Windows Azure Storage. We also ported the application to Ruby on Rails for demonstration purposes. Visitors to the stand were surprised that this was even possible. Why should Java developers be interested in Windows Azure? Windows Azure Storage consists of Blobs, Queues and Tables. The storage is scalable, durable, secure and cost-effective. Using the WindowsAzure4j library, it's easy to use, and takes just a few lines of code. If you are writing an application with large data storage requirements, or you want an offsite backup, it makes a lot of sense. Running Java applications in Azure Compute is straightforward with tools like the Tomcat Solution Accelerator (http://code.msdn.microsoft.com/winazuretomcat )and AzureRunMe (http://azurerunme.codeplex.com/ ). The Windows Azure AppFabric Service Bus can also be used to connect heterogeneous systems running on different networks and in different data centres. How can The Service Bus be considered an interoperability solution? I think that the Windows Azure AppFabric Service Bus is one of Microsoft’s best kept secrets. Think of it as “a globally scalable application plumbing kit in the sky”. If you have used Enterprise Service Buses before, you’ll be familiar with the concept. Applications can connect to the service bus to securely exchange data – these can be point to point or multicast links. With the AppFabric Service Bus, the applications can exist anywhere that has access to the Internet and the connections can traverse firewalls. This makes it easy to extend or scale your application or reach out to other networks and technologies. For example, let’s say you have a SQL Server database running on premises and you want to expose the data to a Java application running in the cloud. You could set up a point to point Service Bus connection and use JDBC. Traditionally this would have been difficult or impossible without punching holes in firewalls and compromising security. Rob Blackwell is R&D Director at Active Web Solutions, www.aws.net , a Microsoft Gold Partner specialising in leading edge software solutions. He is an occasional writer and conference speaker and blogs at www.robblackwell.org.uk Related Links: UK Azure Online Community – join today. UK Windows Azure Site Start working with Windows Azure

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  • #twitter for Windows Phone 7 protips (#wp7)

    - by Laurent Bugnion
    I started tweeting a list of “protips” (or whatever you want to call that) related to the Twitter for Windows Phone 7 application. Since I worked as integrator on this app, my tasks involved integrating design assets in all screens, and so I had an insider view on all the screens (and that is really a LOT of screens :) Seeing some comments about the app made me understand that most users out there don’t realize how rich the application is, and how many features are available. So without further ado, here we go, a list of Twitter for WP7 protips: (note: I will extend the list if I think of new stuff, and maybe add some screenshots later). Check the dark theme in the application settings! Select a tweet, menu, Translate. Search, Nearby looks for tweets near you Custom searches can be saved. They synch up with web twitter too! Multi language support, independant from OS. supports EN, FR, DE, IT, ES Multiple accounts are supported, simply define them in the Settings Even without a Twitter account, experience is super rich. Trends, Suggested, Nearby, searches etc... Select a tweet, then press Replies To to see the whole conversation Compose, menu, Hashtags. Enter a hashtag and press Add. List is saved for the next time. Select a tweet with location info (like my own). Press the location name to see all Nearby tweets Want to remove location information just for one tweet? Press on the Places button in app bar then Clear Place Settings, General to toggle between Username/Fullname display, Relative/Absolute date/time and more Upload a picture directly from compose screen to TwitPic, yFrog or TweetPhoto (service selection in Settings) Settings, About, Support to see a log of app errors and email it to support (use wisely please) Tap your username to see your profile. Then Menu, Edit Profile to edit your info, including your picture Tap on any user's name to see his profile, tweets, mentions and favorites in a Pivot Happy Tweeting! Laurent   Laurent Bugnion (GalaSoft) Subscribe | Twitter | Facebook | Flickr | LinkedIn

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  • What I&rsquo;m working on for this blog&hellip;

    - by marc dekeyser
    Yes it has gone quiet again for the time being! As I am in training for Exchange 2013 and have the need to keep some customers happy (well, we all have to do something to earn our keep ;)) time to write blog posts or even work on my little side projects is limited. So for the time being there are no new blog posts coming but I’d like to tell you that you can expect posts on the following topics: * Automating lab server deployments (Using WDS and MDT 2012 RU1) * Scripts to automate application installations (and integration with the above) * Exchange 2013 posts * Exchange 2013 automation scripts (since I’m already seeing where I could do something here :P) As always, I’m still taking requests…

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  • Load and Web Performance Testing using Visual Studio Ultimate 2010-Part 3

    - by Tarun Arora
    Welcome back once again, in Part 1 of Load and Web Performance Testing using Visual Studio 2010 I talked about why Performance Testing the application is important, the test tools available in Visual Studio Ultimate 2010 and various test rig topologies, in Part 2 of Load and Web Performance Testing using Visual Studio 2010 I discussed the details of web performance & load tests as well as why it’s important to follow a goal based pattern while performance testing your application. In part 3 I’ll be discussing Test Result Analysis, Test Result Drill through, Test Report Generation, Test Run Comparison, Asp.net Profiler and some closing thoughts. Test Results – I see some creepy worms! In Part 2 we put together a web performance test and a load test, lets run the test to see load test to see how the Web site responds to the load simulation. While the load test is running you will be able to see close to real time analysis in the Load Test Analyser window. You can use the Load Test Analyser to conduct load test analysis in three ways: Monitor a running load test - A condensed set of the performance counter data is maintained in memory. To prevent the results memory requirements from growing unbounded, up to 200 samples for each performance counter are maintained. This includes 100 evenly spaced samples that span the current elapsed time of the run and the most recent 100 samples.         After the load test run is completed - The test controller spools all collected performance counter data to a database while the test is running. Additional data, such as timing details and error details, is loaded into the database when the test completes. The performance data for a completed test is loaded from the database and analysed by the Load Test Analyser. Below you can see a screen shot of the summary view, this provides key results in a format that is compact and easy to read. You can also print the load test summary, this is generated after the test has completed or been stopped.         Analyse the load test results of a previously run load test – We’ll see this in the section where i discuss comparison between two test runs. The performance counters can be plotted on the graphs. You also have the option to highlight a selected part of the test and view details, drill down to the user activity chart where you can hover over to see more details of the test run.   Generate Report => Test Run Comparisons The level of reports you can generate using the Load Test Analyser is astonishing. You have the option to create excel reports and conduct side by side analysis of two test results or to track trend analysis. The tools also allows you to export the graph data either to MS Excel or to a CSV file. You can view the ASP.NET profiler report to conduct further analysis as well. View Data and Diagnostic Attachments opens the Choose Diagnostic Data Adapter Attachment dialog box to select an adapter to analyse the result type. For example, you can select an IntelliTrace adapter, click OK and open the IntelliTrace summary for the test agent that was used in the load test.   Compare results This creates a set of reports that compares the data from two load test results using tables and bar charts. I have taken these screen shots from the MSDN documentation, I would highly recommend exploring the wealth of knowledge available on MSDN. Leaving Thoughts While load testing the application with an excessive load for a longer duration of time, i managed to bring the IIS to its knees by piling up a huge queue of requests waiting to be processed. This clearly means that the IIS had run out of threads as all the threads were busy processing existing request, one easy way of fixing this is by increasing the default number of allocated threads, but this might escalate the problem. The better suggestion is to try and drill down to the actual root cause of the problem. When ever the garbage collection runs it stops processing any pages so all requests that come in during that period are queued up, but realistically the garbage collection completes in fraction of a a second. To understand this better lets look at the .net heap, it is divided into large heap and small heap, anything greater than 85kB in size will be allocated to the Large object heap, the Large object heap is non compacting and remember large objects are expensive to move around, so if you are allocating something in the large object heap, make sure that you really need it! The small object heap on the other hand is divided into generations, so all objects that are supposed to be short-lived are suppose to live in Gen-0 and the long living objects eventually move to Gen-2 as garbage collection goes through.  As you can see in the picture below all < 85 KB size objects are first assigned to Gen-0, when Gen-0 fills up and a new object comes in and finds Gen-0 full, the garbage collection process is started, the process checks for all the dead objects and assigns them as the valid candidate for deletion to free up memory and promotes all the remaining objects in Gen-0 to Gen-1. So in the future when ever you clean up Gen-1 you have to clean up Gen-0 as well. When you fill up Gen – 0 again, all of Gen – 1 dead objects are drenched and rest are moved to Gen-2 and Gen-0 objects are moved to Gen-1 to free up Gen-0, but by this time your Garbage collection process has started to take much more time than it usually takes. Now as I mentioned earlier when garbage collection is being run all page requests that come in during that period are queued up. Does this explain why possibly page requests are getting queued up, apart from this it could also be the case that you are waiting for a long running database process to complete.      Lets explore the heap a bit more… What is really a case of crisis is when the objects are living long enough to make it to Gen-2 and then dying, this is definitely a high cost operation. But sometimes you need objects in memory, for example when you cache data you hold on to the objects because you need to use them right across the user session, which is acceptable. But if you wanted to see what extreme caching can do to your server then write a simple application that chucks in a lot of data in cache, run a load test over it for about 10-15 minutes, forcing a lot of data in memory causing the heap to run out of memory. If you get to such a state where you start running out of memory the IIS as a mode of recovery restarts the worker process. It is great way to free up all your memory in the heap but this would clear the cache. The problem with this is if the customer had 10 items in their shopping basket and that data was stored in the application cache, the user basket will now be empty forcing them either to get frustrated and go to a competitor website or if the customer is really patient, give it another try! How can you address this, well two ways of addressing this; 1. Workaround – A x86 bit processor only allows a maximum of 4GB of RAM, this means the machine effectively has around 3.4 GB of RAM available, the OS needs about 1.5 GB of RAM to run efficiently, the IIS and .net framework also need their share of memory, leaving you a heap of around 800 MB to play with. Because Team builds by default build your application in ‘Compile as any mode’ it means the application is build such that it will run in x86 bit mode if run on a x86 bit processor and run in a x64 bit mode if run on a x64 but processor. The problem with this is not all applications are really x64 bit compatible specially if you are using com objects or external libraries. So, as a quick win if you compiled your application in x86 bit mode by changing the compile as any selection to compile as x86 in the team build, you will be able to run your application on a x64 bit machine in x86 bit mode (WOW – By running Windows on Windows) and what that means is, you could use 8GB+ worth of RAM, if you take away everything else your application will roughly get a heap size of at least 4 GB to play with, which is immense. If you need a heap size of more than 4 GB you have either build a software for NASA or there is something fundamentally wrong in your application. 2. Solution – Now that you have put a workaround in place the IIS will not restart the worker process that regularly, which means you can take a breather and start working to get to the root cause of this memory leak. But this begs a question “How do I Identify possible memory leaks in my application?” Well i won’t say that there is one single tool that can tell you where the memory leak is, but trust me, ‘Performance Profiling’ is a great start point, it definitely gets you started in the right direction, let’s have a look at how. Performance Wizard - Start the Performance Wizard and select Instrumentation, this lets you measure function call counts and timings. Before running the performance session right click the performance session settings and chose properties from the context menu to bring up the Performance session properties page and as shown in the screen shot below, check the check boxes in the group ‘.NET memory profiling collection’ namely ‘Collect .NET object allocation information’ and ‘Also collect the .NET Object lifetime information’.    Now if you fire off the profiling session on your pages you will notice that the results allows you to view ‘Object Lifetime’ which shows you the number of objects that made it to Gen-0, Gen-1, Gen-2, Large heap, etc. Another great feature about the profile is that if your application has > 5% cases where objects die right after making to the Gen-2 storage a threshold alert is generated to alert you. Since you have the option to also view the most expensive methods and by capturing the IntelliTrace data you can drill in to narrow down to the line of code that is the root cause of the problem. Well now that we have seen how crucial memory management is and how easy Visual Studio Ultimate 2010 makes it for us to identify and reproduce the problem with the best of breed tools in the product. Caching One of the main ways to improve performance is Caching. Which basically means you tell the web server that instead of going to the database for each request you keep the data in the webserver and when the user asks for it you serve it from the webserver itself. BUT that can have consequences! Let’s look at some code, trust me caching code is not very intuitive, I define a cache key for almost all searches made through the common search page and cache the results. The approach works fine, first time i get the data from the database and second time data is served from the cache, significant performance improvement, EXCEPT when two users try to do the same operation and run into each other. But it is easy to handle this by adding the lock as you can see in the snippet below. So, as long as a user comes in and finds that the cache is empty, the user locks and starts to get the cache no more concurrency issues. But lets say you are processing 10 requests per second, by the time i have locked the operation to get the results from the database, 9 other users came in and found that the cache key is null so after i have come out and populated the cache they will still go in to get the results again. The application will still be faster because the next set of 10 users and so on would continue to get data from the cache. BUT if we added another null check after locking to build the cache and before actual call to the db then the 9 users who follow me would not make the extra trip to the database at all and that would really increase the performance, but didn’t i say that the code won’t be very intuitive, may be you should leave a comment you don’t want another developer to come in and think what a fresher why is he checking for the cache key null twice !!! The downside of caching is, you are storing the data outside of the database and the data could be wrong because the updates applied to the database would make the data cached at the web server out of sync. So, how do you invalidate the cache? Well if you only had one way of updating the data lets say only one entry point to the data update you can write some logic to say that every time new data is entered set the cache object to null. But this approach will not work as soon as you have several ways of feeding data to the system or your system is scaled out across a farm of web servers. The perfect solution to this is Micro Caching which means you cache the query for a set time duration and invalidate the cache after that set duration. The advantage is every time the user queries for that data with in the time span for which you have cached the results there are no calls made to the database and the data is served right from the server which makes the response immensely quick. Now figuring out the appropriate time span for which you micro cache the query results really depends on the application. Lets say your website gets 10 requests per second, if you retain the cache results for even 1 minute you will have immense performance gains. You would reduce 90% hits to the database for searching. Ever wondered why when you go to e-bookers.com or xpedia.com or yatra.com to book a flight and you click on the book button because the fare seems too exciting and you get an error message telling you that the fare is not valid any more. Yes, exactly => That is a cache failure! These travel sites or price compare engines are not going to hit the database every time you hit the compare button instead the results will be served from the cache, because the query results are micro cached, its a perfect trade-off, by micro caching the results the site gains 100% performance benefits but every once in a while annoys a customer because the fare has expired. But the trade off works in the favour of these sites as they are still able to process up to 30+ page requests per second which means cater to the site traffic by may be losing 1 customer every once in a while to a competitor who is also using a similar caching technique what are the odds that the user will not come back to their site sooner or later? Recap   Resources Below are some Key resource you might like to review. I would highly recommend the documentation, walkthroughs and videos available on MSDN. You can always make use of Fiddler to debug Web Performance Tests. Some community test extensions and plug ins available on Codeplex might also be of interest to you. The Road Ahead Thank you for taking the time out and reading this blog post, you may also want to read Part I and Part II if you haven’t so far. If you enjoyed the post, remember to subscribe to http://feeds.feedburner.com/TarunArora. Questions/Feedback/Suggestions, etc please leave a comment. Next ‘Load Testing in the cloud’, I’ll be working on exploring the possibilities of running Test controller/Agents in the Cloud. See you on the other side! Thank You!   Share this post : CodeProject

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  • It&rsquo;s All About Expectation Management

    - by D'Arcy Lussier
    I saw this tweet from Gerald Weinberg today: I’d expand on this – its not just managers, its our clients as well. With so much focus on “agile” and reducing the amount of wasteful documentation created, those that typically consume traditional deliverables haven’t caught up. For many, there still is a correlation between seeing a mountain of paper, or a 30 page Word document, or a 40 slide PowerPoint, and feeling like some “work” was done. The “Value Driven Development” movement is still in its infancy, even with the adoption and success stories. So, we have two options – we can complain about it, or we can learn how to live with it while continuing to evangelize about the benefits of value over bloat. The reality is that perceived value is still value, so what’s important – especially in a situation as Gerald mentions where management or clients don’t understand the work – is to find out what the manager/client values and deliver to that. That doesn’t mean you don’t discuss it. That doesn’t mean that if you see risks being represented in what a manager/client is asking you don’t question it and provide alternatives. But it does mean that you don’t slam the door on it – you don’t just toss it aside and ignore what their perceived value is. The world isn’t perfect, primarily because its filled with imperfect people. The only way to get better is to engage and not dismiss each other, even if we disagree on value.

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  • Why I&rsquo;m *NOT* Attending MOSOConf

    - by D'Arcy Lussier
    It’s my daughter’s birthday on Saturday, she turns 10! Lot’s of party planning to do this week! What, you thought this was going to be a rant post? Hope everyone has a fantastic time at MOSOConf and congrats to the organizers for putting on another fantastic event! Btw, if you’re looking to get even more mobile and web development goodness, come check out Prairie IT Pro & Dev Con in Regina this October – we just announced our current session/speaker line-up and we’ll be adding more sessions over the summer! Click the image below to visit the event site!

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  • Sam Abraham To Speak about MVC & MVVM at InterClick on May 19th

    - by Sam Abraham
    My next speaking engagement will be taking place at InterClick in Boca Raton, FL on Wednesday May 19th 2010.  Here is a quick abstract of what I will be blabbing about: MVC & MVVM are two of many buzzwords under the Architecture Spotlight as means of achieving true separation of concerns between data, business logic and UI layers. In this session, we will be discussing the basic concepts of Microsoft MVC and demonstrating the ease of creating a new MVC project and related Unit Tests within VS2010. We will then move to introduce MVVM as a design paradigm and incorporating that into an MS MVC application structure. Next, we will take a look at MVVM in the context of a sample Silverlight application. Throughout our talk we will be demonstrating various features of the latest and greatest VS2010. You can get more information about the event and the speaker, as well as register to attend at this link: http://sherstaff.com/EventSignUp.aspx?EventID=777 Look forward to seeing you all there.

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  • Productivity Tips

    - by Brian T. Jackett
    A few months ago during my first end of year review at Microsoft I was doing an assessment of my year.  One of my personal goals to come out of this reflection was to improve my personal productivity.  While I hear many people say “I wish I had more hours in the day so that I could get more done” I feel like that is the wrong approach.  There is an inherent assumption that you are being productive with your time that you already have and thus more time would allow you to be as productive given more time.    Instead of wishing I could add more hours to the day I’ve begun adopting a number of processes or behavior changes in my personal life to make better use of my time with the goal of improving productivity.  The areas of focus are as follows: Focus Processes Tools Personal health Email Note: A number of these topics have spawned from reading Scott Hanselman’s blog posts on productivity, reading of David Allen’s book Getting Things Done, and discussions with friends and coworkers who had great insights into this topic.   Focus Pre-reading / viewing: Overcome your work addiction Millennials paralyzed by choice Its Not What You Read Its What You Ignore (Scott Hanselman video)    I highly recommend Scott Hanselman’s video above and this post before continuing with this article.  It is well worth the 40+ mins price of admission for the video and couple minutes for article.  One key takeaway for me was listing out my activities in an average week and realizing which ones held little or no value to me.  We all have a finite amount of time to work each day.  Do you know how much time and effort you spend on various aspects of your life (family, friends, religion, work, personal happiness, etc.)?  Do your actions and commitments reflect your priorities?    The biggest time consumers with little value for me were time spent on social media services (Twitter and Facebook), playing an MMO video game, and watching TV.  I still check up on Facebook, Twitter, Microsoft internal chat forums, and other services to keep contact with others but I’ve reduced that time significantly.  As for TV I’ve cut the cord and no longer subscribe to cable TV.  Instead I use Netflix, RedBox, and over the air channels but again with reduced time consumption.  With the time I’ve freed up I’m back to working out 2-3 times a week and reading 4 nights a week (both of which I had been neglecting previously).  I’ll mention a few tools for helping measure your time in the Tools section.   Processes    Do not multi-task.  I’ll say it again.  Do not multi-task.  There is no such thing as multi tasking.  The human brain is optimized to work on one thing at a time.  When you are “multi-tasking” you are really doing 2 or more things at less than 100%, usually by a wide margin.  I take pride in my work and when I’m doing something less than 100% the results typically degrade rapidly.    Now there are some ways of bending the rules of physics for this one.  There is the notion of getting a double amount of work done in the same timeframe.  Some examples would be listening to podcasts / watching a movie while working out, using a treadmill as your work desk, or reading while in the bathroom.    Personally I’ve found good results in combining one task that does not require focus (making dinner, playing certain video games, working out) and one task that does (watching a movie, listening to podcasts).  I believe this is related to me being a visual and kinesthetic (using my hands or actually doing it) learner.  I’m terrible with auditory learning.  My fiance and I joke that sometimes we talk and talk to each other but never really hear each other.   Goals / Tasks    Goals can give us direction in life and a sense of accomplishment when we complete them.  Goals can also overwhelm us and give us a sense of failure when we don’t complete them.  I propose that you shift your perspective and not dwell on all of the things that you haven’t gotten done, but focus instead on regularly setting measureable goals that are within reason of accomplishing.    At the end of each time frame have a retrospective to review your progress.  Do not feel guilty about what you did not accomplish.  Feel proud of what you did accomplish and readjust your goals for the next time frame to more attainable goals.  Here is a sample schedule I’ve seen proposed by some.  I have not consistently set goals for each timeframe, but I do typically set 3 small goals a day (this blog post is #2 for today). Each day set 3 small goals Each week set 3 medium goals Each month set 1 large goal Each year set 2 very large goals   Tools    Tools are an extension of our human body.  They help us extend beyond what we can physically and mentally do.  Below are some tools I use almost daily or have found useful as of late. Disclaimer: I am not getting endorsed to promote any of these products.  I just happen to like them and find them useful. Instapaper – Save internet links for reading later.  There are many tools like this but I’ve found this to be a great one.  There is even a “read it later” JavaScript button you can add to your browser so when you navigate to a site it will then add this to your list. Stacks for Instapaper – A Windows Phone 7 app for reading my Instapaper articles on the go.  It does require a subscription to Instapaper (nominal $3 every three months) but is easily worth the cost.  Alternatively you can set up your Kindle to sync with Instapaper easily but I haven’t done so. SlapDash Podcast – Apps for Windows Phone and  Windows 8 (possibly other platforms) to sync podcast viewing / listening across multiple devices.  Now that I have my Surface RT device (which I love) this is making my consumption easier to manage. Feed Reader – Simple Windows 8 app for quickly catching up on my RSS feeds.  I used to have hundreds of unread items all the time.  Now I’m down to 20-50 regularly and it is much easier and faster to consume on my Surface RT.  There is also a free version (which I use) and I can’t see much different between the free and paid versions currently. Rescue Time – Have you ever wondered how much time you’ve spent on websites vs. email vs. “doing work”?  This service tracks your computer actions and then lets you report on them.  This can help you quantitatively identify areas where your actions are not in line with your priorities. PowerShell – Windows automation tool.  It is now built into every client and server OS.  This tool has saved me days (and I mean the full 24 hrs worth) of time and effort in the past year alone.  If you haven’t started learning PowerShell and you administrating any Windows OS or server product you need to start today. Various blogging tools – I wrote a post a couple years ago called How I Blog about my blogging process and tools used.  Almost all of it still applies today.   Personal Health    Some of these may be common sense or debatable, but I’ve found them to help prioritize my daily activities. Get plenty of sleep on a regular basis.  Sacrificing sleep too many nights a week negatively impacts your cognition, attitude, and overall health. Exercise at least three days.  Exercise could be lifting weights, taking the stairs up multiple flights of stairs, walking for 20 mins, or a number of other "non-traditional” activities.  I find that regular exercise helps with sleep and improves my overall attitude. Eat a well balanced diet.  Too much sugar, caffeine, junk food, etc. are not good for your body.  This is not a matter of losing weight but taking care of your body and helping you perform at your peak potential.   Email    Email can be one of the biggest time consumers (i.e. waster) if you aren’t careful. Time box your email usage.  Set a meeting invite for yourself if necessary to limit how much time you spend checking email. Use rules to prioritize your email.  Email from external customers, my manager, or include me directly on the To line go into my inbox.  Everything else goes a level down and I have 30+ rules to further sort it, mostly distribution lists. Use keyboard shortcuts (when available).  I use Outlook for my primary email and am constantly hitting Alt + S to send, Ctrl + 1 for my inbox, Ctrl + 2 for my calendar, Space / Tab / Shift + Tab to mark items as read, and a number of other useful commands.  Learn them and you’ll see your speed getting through emails increase. Keep emails short.  No one Few people like reading through long emails.  The first line should state exactly why you are sending the email followed by a 3-4 lines to support it.  Anything longer might be better suited as a phone call or in person discussion.   Conclusion    In this post I walked through various tips and tricks I’ve found for improving personal productivity.  It is a mix of re-focusing on the things that matter, using tools to assist in your efforts, and cutting out actions that are not aligned with your priorities.  I originally had a whole section on keyboard shortcuts, but with my recent purchase of the Surface RT I’m finding that touch gestures have replaced numerous keyboard commands that I used to need.  I see a big future in touch enabled devices.  Hopefully some of these tips help you out.  If you have any tools, tips, or ideas you would like to share feel free to add in the comments section.         -Frog Out   Links Scott Hanselman Productivity posts http://www.hanselman.com/blog/CategoryView.aspx?category=Productivity Overcome your work addiction http://blogs.hbr.org/hbsfaculty/2012/05/overcome-your-work-addiction.html?awid=5512355740280659420-3271   Millennials paralyzed by choice http://priyaparker.com/blog/millennials-paralyzed-by-choice   Its Not What You Read Its What You Ignore (video) http://www.hanselman.com/blog/ItsNotWhatYouReadItsWhatYouIgnoreVideoOfScottHanselmansPersonalProductivityTips.aspx   Cutting the cord – Jeff Blankenburg http://www.jeffblankenburg.com/2011/04/06/cutting-the-cord/   Building a sitting standing desk – Eric Harlan http://www.ericharlan.com/Everything_Else/building-a-sitting-standing-desk-a229.html   Instapaper http://www.instapaper.com/u   Stacks for Instapaper http://www.stacksforinstapaper.com/   Slapdash Podcast Windows Phone -  http://www.windowsphone.com/en-us/store/app/slapdash-podcasts/90e8b121-080b-e011-9264-00237de2db9e Windows 8 - http://apps.microsoft.com/webpdp/en-us/app/slapdash-podcasts/0c62e66a-f2e4-4403-af88-3430a821741e/m/ROW   Feed Reader http://apps.microsoft.com/webpdp/en-us/app/feed-reader/d03199c9-8e08-469a-bda1-7963099840cc/m/ROW   Rescue Time http://www.rescuetime.com/   PowerShell Script Center http://technet.microsoft.com/en-us/scriptcenter/bb410849.aspx

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  • Troubleshooting SQL Azure Connectivity

    - by kaleidoscope
    Technorati Tags: Rituraj,Connectivity Issues with SQL Azure Troubleshooting SQL Azure Connectivity How to resolve some of the common connectivity error messages that you would see while connecting to SQL Azure A transport-level error has occurred when receiving results from the server. (Provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.) System.Data.SqlClient.SqlException: Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding. The statement has been terminated. An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections Error: Microsoft SQL Native Client: Unable to complete login process due to delay in opening server connection. A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. Some troubleshooting tips a) Verify Azure Firewall Settings and Service Availability     Reference: SQL Azure Firewall - http://msdn.microsoft.com/en-us/library/ee621782.aspx b) Verify that you can reach our Virtual IP     Reference: Telnet Troubleshooting Guide - http://technet.microsoft.com/en-us/library/cc753360(WS.10).aspx    Reference: How to Use TRACERT to Troubleshoot TCP/IP Problems in Windows - http://support.microsoft.com/kb/314868 c) Windows Firewall on the local machine     Frequently Asked Questions - http://msdn.microsoft.com/en-us/library/bb736261(VS.85).aspx     Reference: Windows Firewall with Advanced Security Getting Started Guide - http://technet.microsoft.com/en-us/library/cc748991(WS.10).aspx d) Other Firewall products     Reference: http://www.whatismyip.com/ e) Generate a Network Trace using Microsoft Network Monitor tool    Reference: How to capture network traffic with Network Monitor - http://support.microsoft.com/kb/148942 f) SQL Azure Denial of Service (DOS) Guard SQL Azure utilizes techniques to prevent denial of service attacks. If your connection is getting reset by our service due to a potential DOS attack you would  be able to see a three way handshake established and then a RESET in your network trace.

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  • Silverlight Cream for March 26, 2010 -- #821

    - by Dave Campbell
    In this Issue: Max Paulousky, Christian Schormann, John Papa, Phani Raj, David Anson(-2-, -3-), Brad Abrams(-2-), and Jeff Wilcox(-2-, -3-). Shoutouts: Jeff Wilcox posted his material from mix and some preview TestFramework bits: Unit Testing Silverlight & Windows Phone Applications – talk now online At MIX10, Jeff Wilcox demo'd an app called "Peppermint"... here's the bleeding edge demo: “Peppermint” MIX demo sources Erik Mork and Co. have put out their weekly This Week In Silverlight 3.25.2010 Brad Abrams has all his materials posted for his MIX10 session Mix2010: Search Engine Optimization (SEO) for Microsoft Silverlight... including play-by-play of the demo and all source. Do you use Rooler? Well you should! Watch a video Pete Brown did with Pete Blois on Expression Blend, Windows Phone, Rooler Interested in Silverlight and XNA for WP7? Me too! Michael Klucher has a post outlining the two: Silverlight and XNA Framework Game Development and Compatibility From SilverlightCream.com: Modularity in Silverlight Applications - An Issue With ModuleInitializeException Max Paulousky has a truly ugly error trace listed by way of not having a reference listed, and the obvious simple solution. Next time he'll talk about the difficult situations. Using SketchFlow to Prototype for Windows Phone Christian Schormann has a tutorial up on using Expression Blend to develop for WP7 ... who better than Christian for that task?? Silverlight TV 18: WCF RIA Services Validation John Papa held forth with Nikhil Kothari on WCF RIA Services and validation just prior to MIX10, and was posted yesterday. Building SL3 applications using OData client Library with Vs 2010 RC Phani Raj walks through building an OData consumer in SL3, the first problem you're going to hit, and the easy solution to it. Tip: When creating a DependencyProperty, follow the handy convention of "wrapper+register+static+virtual" David Anson has a couple more of his 'Tips' up... this first is about Dependency Properties again... having a good foundation for all your Dependency Properties is a great way to avoid problems. Tip: Do not assign DependencyProperty values in a constructor; it prevents users from overriding them In the next post, David Anson talks about not assigning Dependency Property values in a constructor and gives one of the two ways to get around doing so. Tip: Set DependencyProperty default values in a class's default style if it's more convenient In his latest post, David Anson gives the second way to avoid setting a Dependency Property value in the constructor. Silverlight 4 + RIA Services - Ready for Business: Search Engine Optimization (SEO) Brad Abrams Abrams adds SEO to the tutorial series he's doing. He begins with his PDC09 session material on the subject and then takes off on a great detailed tutorial all with source. Silverlight 4 + RIA Services - Ready for Business: Localizing Business Application Brad Abrams then discusses localization and Silverlight in another detailed tutorial with all code included. Silverlight Toolkit and the Windows Phone: WrapPanel, and a few others Jeff Wilcox has a few WP7 posts I'm going to push today. This first is from earlier this week and is about using the Toolkit in WP7 and better than that, he includes the bits you need if all you want is the WrapPanel Data binding user settings in Windows Phone applications In the next one from yesterday, Jeff Wilcox demonstrates saving some user info in Isolated Storage to improve the user experience, and shares all the necessary plumbing files, and other external links as well. Displaying 2D QR barcodes in Windows Phone applications In a post from today, Jeff Wilcox ported his Silverlight 2D QR Barcode app from last year into WP7 ... just very cool... get the source and display your Microsoft Tag. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone    MIX10

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  • What Every Developer Should Know About MSI Components

    - by Alois Kraus
    Hopefully nothing. But if you have to do more than simple XCopy deployment and you need to support updates, upgrades and perhaps side by side scenarios there is no way around MSI. You can create Msi files with a Visual Studio Setup project which is severely limited or you can use the Windows Installer Toolset. I cannot talk about WIX with my German colleagues because WIX has a very special meaning. It is funny to always use the long name when I talk about deployment possibilities. Alternatively you can buy commercial tools which help you to author Msi files but I am not sure how good they are. Given enough pain with existing solutions you can also learn the MSI Apis and create your own packaging solution. If I were you I would use either a commercial visual tool when you do easy deployments or use the free Windows Installer Toolset. Once you know the WIX schema you can create well formed wix xml files easily with any editor. Then you can “compile” from the wxs files your Msi package. Recently I had the “pleasure” to get my hands dirty with C++ (again) and the MSI technology. Installation is a complex topic but after several month of digging into arcane MSI issues I can safely say that there should exist an easier way to install and update files as today. I am not alone with this statement as John Robbins (creator of the cool tool Paraffin) states: “.. It's a brittle and scary API in Windows …”. To help other people struggling with installation issues I present you the advice I (and others) found useful and what will happen if you ignore this advice. What is a MSI file? A MSI file is basically a database with tables which reference each other to control how your un/installation should work. The basic idea is that you declare via these tables what you want to install and MSI controls the how to get your stuff onto or off your machine. Your “stuff” consists usually of files, registry keys, shortcuts and environment variables. Therefore the most important tables are File, Registry, Environment and Shortcut table which define what will be un/installed. The key to master MSI is that every resource (file, registry key ,…) is associated with a MSI component. The actual payload consists of compressed files in the CAB format which can either be embedded into the MSI file or reside beside the MSI file or in a subdirectory below it. To examine MSI files you need Orca a free MSI editor provided by MS. There is also another free editor called Super Orca which does support diffs between MSI and it does not lock the MSI files. But since Orca comes with a shell extension I tend to use only Orca because it is so easy to right click on a MSI file and open it with this tool. How Do I Install It? Double click it. This does work for fresh installations as well as major upgrades. Updates need to be installed via the command line via msiexec /i <msi> REINSTALL=ALL REINSTALLMODE=vomus   This tells the installer to reinstall all already installed features (new features will NOT be installed). The reinstallmode letters do force an overwrite of the old cached package in the %WINDIR%\Installer folder. All files, shortcuts and registry keys are redeployed if they are missing or need to be replaced with a newer version. When things did go really wrong and you want to overwrite everything unconditionally use REINSTALLMODE=vamus. How To Enable MSI Logs? You can download a MSI from Microsoft which installs some registry keys to enable full MSI logging. The log files can be found in your %TEMP% folder and are called MSIxxxx.log. Alternatively you can add to your msiexec command line the option msiexec …. /l*vx <LogFileName> Personally I find it rather strange that * does not mean full logging. To really get all logs I need to add v and x which is documented in the msiexec help but I still find this behavior unintuitive. What are MSI components? The whole MSI logic is bound to the concept of MSI components. Nearly every msi table has a Component column which binds an installable resource to a component. Below are the screenshots of the FeatureComponents and Component table of an example MSI. The Feature table defines basically the feature hierarchy.  To find out what belongs to a feature you need to look at the FeatureComponents table where for each feature the components are listed which will be installed when a feature is installed. The MSI components are defined in the  Component table. This table has as first column the component name and as second column the component id which is a GUID. All resources you want to install belong to a MSI component. Therefore nearly all MSI tables have a Component_ column which contains the component name. If you look e.g. a the File table you see that every file belongs to a component which is true for all other tables which install resources. The component table is the glue between all other tables which contain the resources you want to install. So far so easy. Why is MSI then so complex? Most MSI problems arise from the fact that you did violate a MSI component rule in one or the other way. When you install a feature the reference count for all components belonging to this feature will increase by one. If your component is installed by more than one feature it will get a higher refcount. When you uninstall a feature its refcount will drop by one. Interesting things happen if the component reference count reaches zero: Then all associated resources will be deleted. That looks like a reasonable thing and it is. What it makes complex are the strange component rules you have to follow. Below are some important component rules from the Tao of the Windows Installer … Rule 16: Follow Component Rules Components are a very important part of the Installer technology. They are the means whereby the Installer manages the resources that make up your application. The SDK provides the following guidelines for creating components in your package: Never create two components that install a resource under the same name and target location. If a resource must be duplicated in multiple components, change its name or target location in each component. This rule should be applied across applications, products, product versions, and companies. Two components must not have the same key path file. This is a consequence of the previous rule. The key path value points to a particular file or folder belonging to the component that the installer uses to detect the component. If two components had the same key path file, the installer would be unable to distinguish which component is installed. Two components however may share a key path folder. Do not create a version of a component that is incompatible with all previous versions of the component. This rule should be applied across applications, products, product versions, and companies. Do not create components containing resources that will need to be installed into more than one directory on the user’s system. The installer installs all of the resources in a component into the same directory. It is not possible to install some resources into subdirectories. Do not include more than one COM server per component. If a component contains a COM server, this must be the key path for the component. Do not specify more than one file per component as a target for the Start menu or a Desktop shortcut. … And these rules do not even talk about component ids, update packages and upgrades which you need to understand as well. Lets suppose you install two MSIs (MSI1 and MSI2) which have the same ComponentId but different component names. Both do install the same file. What will happen when you uninstall MSI2?   Hm the file should stay there. But the component names are different. Yes and yes. But MSI uses not use the component name as key for the refcount. Instead the ComponentId column of the Component table which contains a GUID is used as identifier under which the refcount is stored. The components Comp1 and Comp2 are identical from the MSI perspective. After the installation of both MSIs the Component with the Id {100000….} has a refcount of two. After uninstallation of one MSI there is still a refcount of one which drops to zero just as expected when we uninstall the last msi. Then the file which was the same for both MSIs is deleted. You should remember that MSI keeps a refcount across MSIs for components with the same component id. MSI does manage components not the resources you did install. The resources associated with a component are then and only then deleted when the refcount of the component reaches zero.   The dependencies between features, components and resources can be described as relations. m,k are numbers >= 1, n can be 0. Inside a MSI the following relations are valid Feature    1  –> n Components Component    1 –> m Features Component      1  –>  k Resources These relations express that one feature can install several components and features can share components between them. Every (meaningful) component will install at least one resource which means that its name (primary key to stay in database speak) does occur in some other table in the Component column as value which installs some resource. Lets make it clear with an example. We want to install with the feature MainFeature some files a registry key and a shortcut. We can then create components Comp1..3 which are referenced by the resources defined in the corresponding tables.   Feature Component Registry File Shortcuts MainFeature Comp1 RegistryKey1     MainFeature Comp2   File.txt   MainFeature Comp3   File2.txt Shortcut to File2.txt   It is illegal that the same resource is part of more than one component since this would break the refcount mechanism. Lets illustrate this:            Feature ComponentId Resource Reference Count Feature1 {1000-…} File1.txt 1 Feature2 {2000-….} File1.txt 1 The installation part works well but what happens when you uninstall Feature2? Component {20000…} gets a refcount of zero where MSI deletes all resources belonging to this component. In this case File1.txt will be deleted. But Feature1 still has another component {10000…} with a refcount of one which means that the file was deleted too early. You just have ruined your installation. To fix it you then need to click on the Repair button under Add/Remove Programs to let MSI reinstall any missing registry keys, files or shortcuts. The vigilant reader might has noticed that there is more in the Component table. Beside its name and GUID it has also an installation directory, attributes and a KeyPath. The KeyPath is a reference to a file or registry key which is used to detect if the component is already installed. This becomes important when you repair or uninstall a component. To find out if the component is already installed MSI checks if the registry key or file referenced by the KeyPath property does exist. When it does not exist it assumes that it was either already uninstalled (can lead to problems during uninstall) or that it is already installed and all is fine. Why is this detail so important? Lets put all files into one component. The KeyPath should be then one of the files of your component to check if it was installed or not. When your installation becomes corrupt because a file was deleted you cannot repair it with the Repair button under Add/Remove Programs because MSI checks the component integrity via the Resource referenced by its KeyPath. As long as you did not delete the KeyPath file MSI thinks all resources with your component are installed and never executes any repair action. You get even more trouble when you try to remove files during an upgrade (you cannot remove files during an update) from your super component which contains all files. The only way out and therefore best practice is to assign for every resource you want to install an extra component. This ensures painless updatability and repairs and you have much less effort to remove specific files during an upgrade. In effect you get this best practice relation Feature 1  –> n Components Component   1  –>  1 Resources MSI Component Rules Rule 1 – One component per resource Every resource you want to install (file, registry key, value, environment value, shortcut, directory, …) must get its own component which does never change between versions as long as the install location is the same. Penalty If you add more than one resources to a component you will break the repair capability of MSI because the KeyPath is used to check if the component needs repair. MSI ComponentId Files MSI 1.0 {1000} File1-5 MSI 2.0 {2000} File2-5 You want to remove File1 in version 2.0 of your MSI. Since you want to keep the other files you create a new component and add them there. MSI will delete all files if the component refcount of {1000} drops to zero. The files you want to keep are added to the new component {2000}. Ok that does work if your upgrade does uninstall the old MSI first. This will cause the refcount of all previously installed components to reach zero which means that all files present in version 1.0 are deleted. But there is a faster way to perform your upgrade by first installing your new MSI and then remove the old one.  If you choose this upgrade path then you will loose File1-5 after your upgrade and not only File1 as intended by your new component design.   Rule 2 – Only add, never remove resources from a component If you did follow rule 1 you will not need Rule 2. You can add in a patch more resources to one component. That is ok. But you can never remove anything from it. There are tricky ways around that but I do not want to encourage bad component design. Penalty Lets assume you have 2 MSI files which install under the same component one file   MSI1 MSI2 {1000} - ComponentId {1000} – ComponentId File1.txt File2.txt   When you install and uninstall both MSIs you will end up with an installation where either File1 or File2 will be left. Why? It seems that MSI does not store the resources associated with each component in its internal database. Instead Windows will simply query the MSI that is currently uninstalled for all resources belonging to this component. Since it will find only one file and not two it will only uninstall one file. That is the main reason why you never can remove resources from a component!   Rule 3 Never Remove A Component From an Update MSI. This is the same as if you change the GUID of a component by accident for your new update package. The resulting update package will not contain all components from the previously installed package. Penalty When you remove a component from a feature MSI will set the feature state during update to Advertised and log a warning message into its log file when you did enable MSI logging. SELMGR: ComponentId '{2DCEA1BA-3E27-E222-484C-D0D66AEA4F62}' is registered to feature 'xxxxxxx, but is not present in the Component table.  Removal of components from a feature is not supported! MSI (c) (24:44) [07:53:13:436]: SELMGR: Removal of a component from a feature is not supported Advertised means that MSI treats all components of this feature as not installed. As a consequence during uninstall nothing will be removed since it is not installed! This is not only bad because uninstall does no longer work but this feature will also not get the required patches. All other features which have followed component versioning rules for update packages will be updated but the one faulty feature will not. This results in very hard to find bugs why an update was only partially successful. Things got better with Windows Installer 4.5 but you cannot rely on that nobody will use an older installer. It is a good idea to add to your update msiexec call MSIENFORCEUPGRADECOMPONENTRULES=1 which will abort the installation if you did violate this rule.

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