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• Windows Azure Evolution - Web Sites (aka Antares) Part 1

  - by Shaun

  This is the 3rd post of my Windows Azure Evolution series, focus on the new features and enhancement which was alone with the Windows Azure Platform Upgrade June 2012, announced at the MEET Windows Azure event on 7th June. In the first post I introduced the new preview developer portal and how to works for the existing features such as cloud services, storages and SQL databases. In the second one I talked about the Windows Azure .NET SDK 1.7 on the latest Visual Studio 2012 RC on Windows 8. From this one I will begin to introduce some new features. Now let’s have a look on the first one of them, Windows Azure Web Sites.   Overview Windows Azure Web Sites (WAWS), as known as Antares, was a new feature still in preview stage in this upgrade. It allows people to quickly and easily deploy websites to a highly scalable cloud environment, uses the languages and open source apps of the choice then deploy such as FTP, Git and TFS. It also can be integrated with Windows Azure services like SQL Database, Caching, CDN and Storage easily. After read its introduction we may have a question: since we can deploy a website from both cloud service web role and web site, what’s the different between them? So, let’s have a quick compare.   CLOUD SERVICE WEB SITE OS Windows Server Windows Server Virtualization Windows Azure Virtual Machine Windows Azure Virtual Machine Host IIS IIS Platform ASP.NET WebForm, ASP.NET MVC, WCF ASP.NET WebForm, ASP.NET MVC, PHP Language C#, VB.NET C#, VB.NET, PHP Database SQL Database SQL Database, MySQL Architecture Multi layered, background worker, message queuing, etc.. Simple website with backend database. VS Project Windows Azure Cloud Service ASP.NET Web Form, ASP.NET MVC, etc.. Out-of-box Gallery (none) Drupal, DotNetNuke, WordPress, etc.. Deployment Package upload, Visual Studio publish FTP, Git, TFS, WebMatrix Compute Mode Dedicate VM Shared Across VMs, Dedicate VM Scale Scale up, scale out Scale up, scale out As you can see, there are many difference between the cloud service and web site, but the main point is that, the cloud service focus on those complex architecture web application. For example, if you want to build a website with frontend layer, middle business layer and data access layer, with some background worker process connected through the message queue, then you should better use cloud service, since it provides full control of your code and application. But if you just want to build a personal blog or a  business portal, then you can use the web site. Since the web site have many galleries, you can create them even without any coding and configuration. David Pallmann have an awesome figure explains the benefits between the could service, web site and virtual machine.   Create a Personal Blog in Web Site from Gallery As I mentioned above, one of the big feature in WAWS is to build a website from an existing gallery, which means we don’t need to coding and configure. What we need to do is open the windows azure developer portal and click the NEW button, select WEB SITE and FROM GALLERY. In the popping up windows there are many websites we can choose to use. For example, for personal blog there are Orchard CMS, WordPress; for CMS there are DotNetNuke, Drupal 7, mojoPortal. Let’s select WordPress and click the next button. The next step is to configure the web site. We will need to specify the DNS name and select the subscription and region. Since the WordPress uses MySQL as its backend database, we also need to create a MySQL database as well. Windows Azure Web Sites utilize ClearDB to host the MySQL databases. You cannot create a MySQL database directly from SQL Databases section. Finally, since we selected to create a new MySQL database we need to specify the database name and region in the last step. Also we need to accept the ClearDB’s terms as well. Then windows azure platform will download the WordPress codes and deploy the MySQL database and website. Then it will be ready to use. Select the website and click the BROWSE button, the WordPress administration page will be shown. After configured the WordPress here is my personal web blog on the cloud. It took me no more than 10 minutes to establish without any coding.   Monitor, Configure, Scale and Linked Resources Let’s click into the website I had just created in the portal and have a look on what we can do. In the website details page where are five sections. - Dashboard The overall information about this website, such as the basic usage status, public URL, compute mode, FTP address, subscription and links that we can specify the deployment credentials, TFS and Git publish setting, etc.. - Monitor Some status information such as the CPU usage, memory usage etc., errors, etc.. We can add more metrics by clicking the ADD METRICS button and the bottom as well. - Configure Here we can set the configurations of our website such as the .NET and PHP runtime version, diagnostics settings, application settings and the IIS default documents. - Scale This is something interesting. In WAWS there are two compute mode or called web site mode. One is “shared”, which means our website will be shared with other web sites in a group of windows azure virtual machines. Each web site have its own process (w3wp.exe) with some sandbox technology to isolate from others. When we need to scaling-out our web site in shared mode, we actually increased the working process count. Hence in shared mode we cannot specify the virtual machine size since they are shared across all web sites. This is a little bit different than the scaling mode of the cloud service (hosted service web role and worker role). The other mode called “dedicate”, which means our web site will use the whole windows azure virtual machine. This is the same hosting behavior as cloud service web role. In web role it will be deployed on the virtual machines we specified and all of them are only used by us. In web sites dedicate mode, it’s the same. In this mode when we scaling-out our web site we will use more virtual machines, and each of them will only host our own website. And we can specify the virtual machine size in this mode. In the developer portal we can select which mode we are using from the scale section. In shared mode we can only specify the instance count, but in dedicate mode we can specify the instance size as well as the instance count. - Linked Resource The MySQL database created alone with the creation of our WordPress web site is a linked resource. We can add more linked resources in this section.   Pricing For the web site itself, since this feature is in preview period if you are using shared mode, then you will get free up to 10 web sites. But if you are using dedicate mode, the price would be the virtual machines you are using. For example, if you are using dedicate and configured two middle size virtual machines then you will pay $230.40 per month. If there is SQL Database linked to your web site then they will be charged separately based on the Pay-As-You-Go price. For example a 1GB web edition database costs $9.99 per month. And the bandwidth will be charged as well. For example 10GB outbound data transfer costs $1.20 per month. For more information about the pricing please have a look at the windows azure pricing page.   Summary Windows Azure Web Sites gives us easier and quicker way to create, develop and deploy website to window azure platform. Comparing with the cloud service web role, the WAWS have many out-of-box gallery we can use directly. So if you just want to build a blog, CMS or business portal you don’t need to learn ASP.NET, you don’t need to learn how to configure DotNetNuke, you don’t need to learn how to prepare PHP and MySQL. By using WAWS gallery you can establish a website within 10 minutes without any lines of code. But in some cases we do need to code by ourselves. We may need to tweak the layout of our pages, or we may have a traditional ASP.NET or PHP web application which needed to migrated to the cloud. Besides the gallery WAWS also provides many features to download, upload code. It also provides the feature to integrate with some version control services such as TFS and Git. And it also provides the deploy approaches through FTP and Web Deploy. In the next post I will demonstrate how to use WebMatrix to download and modify the website, and how to use TFS and Git to deploy automatically one our code changes committed.   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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• Oracle Products Reflect Key Trends Shaping Enterprise 2.0

  - by kellsey.ruppel(at)oracle.com

  Following up on his predictions for 2011, we asked Enterprise 2.0 veteran Andy MacMillan to map out the ways Oracle solutions are at the forefront of industry trends--and how Oracle customers can benefit in the coming year. 1. Increase organizational awareness | Oracle WebCenter Suite Oracle WebCenter Suite provides a unique set of capabilities to drive organizational awareness. In particular, the expansive activity graph connects users directly to key enterprise applications, activities, and interests. In this way, applicable and critical business information is automatically and immediately visible--in the context of key tasks--via real-time dashboards and comprehensive reporting. Oracle WebCenter Suite also integrates key E2.0 services, such as blogs, wikis, and RSS feeds, into critical business processes, including back-office systems of records such as ERP and CRM systems. 2. Drive online customer engagement | Oracle Real-Time Decisions With more and more business being conducted on the Web, driving increased online customer engagement becomes a critical key to success. This effort is usually spearheaded by an increasingly important executive role, the Head of Online, who usually reports directly to the CMO. To help manage the Web experience online, Oracle solutions are driving a new kind of intelligent social commerce by combining Oracle Universal Content Management, Oracle WebCenter Services, and Oracle Real-Time Decisions with leading e-commerce and product recommendations. Oracle Real-Time Decisions provides multichannel recommendations for content, products, and services--including seamless integration across Web, mobile, and social channels. The result: happier customers, increased customer acquisition and retention, and improved critical success metrics such as shopping cart abandonment. 3. Easily build composite applications | Oracle Application Development Framework Thanks to the shared user experience strategy across Oracle Fusion Middleware, Oracle Fusion Applications and many other Oracle Applications, customers can easily create real, customer-specific composite applications using Oracle WebCenter Suite and Oracle Application Development Framework. Oracle Application Development Framework components provide modular user interface components that can build rich, social composite applications. In addition, a broad set of components spanning BPM, SOA, ECM, and beyond can be quickly and easily incorporated into composite applications. 4. Integrate records management into a global content platform | Oracle Enterprise Content Management 11g Oracle Enterprise Content Management 11g provides leading records management capabilities as part of a unified ECM platform for managing records, documents, Web content, digital assets, enterprise imaging, and application imaging. This unique strategy provides comprehensive records management in a consistent, cost-effective way, and enables organizations to consolidate ECM repositories and connect ECM to critical business applications. 5. Achieve ECM at extreme scale | Oracle WebLogic Server and Oracle Exadata To support the high-performance demands of a unified and rationalized content platform, Oracle has pioneered highly scalable and high-performing ECM infrastructures. Two innovations in particular helped make this happen. The core ECM platform itself moved to an Enterprise Java architecture, so organizations can now use Oracle WebLogic Server for enhanced scalability and manageability. Oracle Enterprise Content Management 11g can leverage Oracle Exadata for extreme performance and scale. Likewise, Oracle Exalogic--Oracle's foundation for cloud computing--enables extreme performance for processor-intensive capabilities such as content conversion or dynamic Web page delivery. Learn more about Oracle's Enterprise 2.0 solutions.

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• Android - passing data between Activities

  - by Bill Osuch

  (To follow along with this, you should understand the basics of starting new activities: Link ) The easiest way to pass data from one activity to another is to create your own custom bundle and pass it to your new class. First, create two new activities called Search and SearchResults (make sure you add the second one you create to the AndroidManifest.xml file!), and create xml layout files for each. Search's file should look like this: <?xml version="1.0" encoding="utf-8"?> <LinearLayout     xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="fill_parent"     android:layout_height="fill_parent"     android:orientation="vertical">     <TextView          android:layout_width="fill_parent"      android:layout_height="wrap_content"      android:text="Name:"/>     <EditText                android:id="@+id/edittext"         android:layout_width="fill_parent"         android:layout_height="wrap_content"/>     <TextView          android:layout_width="fill_parent"         android:layout_height="wrap_content"         android:text="ID Number:"/>     <EditText                android:id="@+id/edittext2"                android:layout_width="fill_parent"                android:layout_height="wrap_content"/>     <Button           android:id="@+id/btnSearch"          android:layout_width="fill_parent"         android:layout_height="wrap_content"         android:text="Search" /> </LinearLayout> and SearchResult's should look like this: <?xml version="1.0" encoding="utf-8"?> <LinearLayout     xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="fill_parent"     android:layout_height="fill_parent"     android:orientation="vertical">     <TextView          android:id="@+id/txtName"         android:layout_width="fill_parent"         android:layout_height="wrap_content"/>     <TextView          android:id="@+id/txtState"         android:layout_width="fill_parent"         android:layout_height="wrap_content"         android:text="No data"/> </LinearLayout> Next, we'll override the OnCreate method of Search: @Override public void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.search);     Button search = (Button) findViewById(R.id.btnSearch);     search.setOnClickListener(new View.OnClickListener() {         public void onClick(View view) {                           Intent intent = new Intent(Search.this, SearchResults.class);              Bundle b = new Bundle();                           EditText txt1 = (EditText) findViewById(R.id.edittext);             EditText txt2 = (EditText) findViewById(R.id.edittext2);                                      b.putString("name", txt1.getText().toString());             b.putInt("state", Integer.parseInt(txt2.getText().toString()));                              //Add the set of extended data to the intent and start it             intent.putExtras(b);             startActivity(intent);          }     }); } This is very similar to the previous example, except here we're creating our own bundle, adding some key/value pairs to it, and adding it to the intent. Now, to retrieve the data, we just need to grab the Bundle that was passed to the new Activity and extract our values from it: @Override public void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.search_results);     Bundle b = getIntent().getExtras();     int value = b.getInt("state", 0);     String name = b.getString("name");             TextView vw1 = (TextView) findViewById(R.id.txtName);     TextView vw2 = (TextView) findViewById(R.id.txtState);             vw1.setText("Name: " + name);     vw2.setText("State: " + String.valueOf(value)); }

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• Ghost team foundation build controllers

  - by Martin Hinshelwood

  Quite often after an upgrade there are things left over. Most of the time they are easy to delete, but sometimes it takes a little effort. Even rarer are those times when something just will not go away no matter how much you try. We have had a ghost team build controller hanging around for a while now, and it had defeated my best efforts to get rid of it. The build controller was from our old TFS server from before our TFS 2010 beta 2 upgrade and was really starting to annoy me. Every time I try to delete it I get the message: Controller cannot be deleted because there are build in progress -Manage Build Controller dialog   Figure: Deleting a ghost controller does not always work. I ended up checking all of our 172 Team Projects for the build that was queued, but did not find anything. Jim Lamb pointed me to the “tbl_BuildQueue” table in the team Project Collection database and sure enough there was the nasty little beggar. Figure: The ghost build was easily spotted Adam Cogan asked me: “Why did you suspect this one?” Well, there are a number of things that led me to suspect it: QueueId is very low: Look at the other items, they are in the thousands not single digits ControllerId: I know there is only one legitimate controller, and I am assuming that 6 relates to “zzUnicorn” DefinitionId: This is a very low number and I looked it up in “tbl_BuildDefinition” and it did not exist QueueTime: As we did not upgrade to TFS 2010 until late 2009 a date of 2008 for a queued build is very suspect Status: A status of 2 means that it is still queued This build must have been queued long ago when we were using TFS 2008, probably a beta, and it never got cleaned up. As controllers are new in TFS 2010 it would have created the “zzUnicorn” controller to handle any build servers that already exist. I had previously deleted the Agent, but leaving the controller just looks untidy. Now that the ghost build has been identified there are two options: Delete the row I would not recommend ever deleting anything from the database to achieve something in TFS. It is really not supported. Set the Status to cancelled (Recommended) This is the best option as TFS will then clean it up itself So I set the Status of this build to 2 (cancelled) and sure enough it disappeared after a couple of minutes and I was then able to then delete the “zzUnicorn” controller. Figure: Almost completely clean Now all I have to do is get rid of that untidy “zzBunyip” agent, but that will require rewriting one of our build scripts which will have to wait for now.   Technorati Tags: ALM,TFBS,TFS 2010

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• How Microsoft Lost the API War - by Joel Spolsky

  - by TechTwaddle

  Came across another gem of an article by Joel Spolsky. It's a pretty old article written in June of 2004, has lot of tidbits and I really enjoyed reading it, so much in fact that I read it twice! So hit the link below and give it a read if you haven't already, How Microsoft Lost the API War - Joel Spolsky excerpt, "I first heard about this from one of the developers of the hit game SimCity, who told me that there was a critical bug in his application: it used memory right after freeing it, a major no-no that happened to work OK on DOS but would not work under Windows where memory that is freed is likely to be snatched up by another running application right away. The testers on the Windows team were going through various popular applications, testing them to make sure they worked OK, but SimCity kept crashing. They reported this to the Windows developers, who disassembled SimCity, stepped through it in a debugger, found the bug, and added special code that checked if SimCity was running, and if it did, ran the memory allocator in a special mode in which you could still use memory after freeing it."

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• Silverlight beyond the basics

  - by Braulio Díez Botella

  Once I have learned the basics of Silverlight, I realized that there was still a lot to learn, architecture, patterns & practices, data access technologies… BUT… there’s plenty of material out there and few available time. I have compiled a set of articles/web casts / posts I found pretty useful for me, and defined a “learning roadmap”.   About the learning road map:    About the links: Basics MVVM Pattern: MSDN Magazine Basics RIA Services: RIA Services Intro RIA Services and Visual Studio 2010 MVVM + PRISM: MVVM + PRISM  MEF: MSDN Magazine RIA Services + MVVM: Mix10 RIA Services + MVVM + MEF: Shawn Wildermuth Series (1) Shawn Wildermuth Series (2) Shawn Wildermuth Series (3) Shawn Wildermuth Series (4) Some of them are based on Beta version of the products, but the core concepts are there and quite well explained. Please if you have other superb references add it on the comments section, hope to build a “version 2” of this post including or your feeback, thanks.

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• SBUG Session: The Enterprise Cache

  - by EltonStoneman

  [Source: http://geekswithblogs.net/EltonStoneman] I did a session on "The Enterprise Cache" at the UK SOA/BPM User Group yesterday which generated some useful discussion. The proposal was for a dedicated caching layer which all app servers and service providers can hook into, sharing resources and common data. The architecture might end up like this: I'll update this post with a link to the slide deck once it's available. The next session will have Udi Dahan walking through nServiceBus, register on EventBrite if you want to come along. Synopsis Looked at the benefits and drawbacks of app-centric isolated caches, compared to an enterprise-wide shared cache running on dedicated nodes; Suggested issues and risks around caching including staleness of data, resource usage, performance and testing; Walked through a generic service cache implemented as a WCF behaviour – suitable for IIS- or BizTalk-hosted services - which I'll be releasing on CodePlex shortly; Listed common options for cache providers and their offerings. Discussion Cache usage. Different value propositions for utilising the cache: improved performance, isolation from underlying systems (e.g. service output caching can have a TTL large enough to cover downtime), reduced resource impact – CPU, memory, SQL and cost (e.g. caching results of paid-for services). Dedicated cache nodes. Preferred over in-host caching provided latency is acceptable. Depending on cache provider, can offer easy scalability and global replication so cache clients always use local nodes. Restriction of AppFabric Caching to Windows Server 2008 not viewed as a concern. Security. Limited security model in most cache providers. Options for securing cache content suggested as custom implementations. Obfuscating keys and serialized values may mean additional security is not needed. Depending on security requirements and architecture, can ensure cache servers only accessible to cache clients via IPsec. Staleness. Generally thought to be an overrated problem. Thinking in line with eventual consistency, that serving up stale data may not be a significant issue. Good technical arguments support this, although I suspect business users will be harder to persuade. Providers. Positive feedback for AppFabric Caching – speed, configurability and richness of the distributed model making it a good enterprise choice. .NET port of memcached well thought of for performance but lack of replication makes it less suitable for these shared scenarios. Replicated fork – repcached – untried and less active than memcached. NCache also well thought of, but Express version too limited for enterprise scenarios, and commercial versions look costly compared to AppFabric.

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• Cloud-Burst 2012&ndash;Windows Azure Developer Conference in Sweden

  - by Alan Smith

  The Sweden Windows Azure Group (SWAG) will running “Cloud-Burst 2012”, a two-day Windows Azure conference hosted at the Microsoft offices in Akalla, near Stockholm on the 27th and 28th September, with an Azure Hands-on Labs Day at AddSkills on the 29th September. The event is free to attend, and will be featuring presentations on the latest Azure technologies from Microsoft MVPs and evangelists. The following presentations will be delivered on the Thursday (27th) and Friday (29th): · Connecting Devices to Windows Azure - Windows Azure Technical Evangelist Brady Gaster · Grid Computing with 256 Windows Azure Worker Roles - Connected System Developer MVP Alan Smith · ‘Warts and all’. The truth about Windows Azure development - BizTalk MVP Charles Young · Using Azure to Integrate Applications - BizTalk MVP Charles Young · Riding the Windows Azure Service Bus: Cross-‘Anything’ Messaging - Windows Azure MVP & Regional Director Christian Weyer · Windows Azure, Identity & Access - and you - Developer Security MVP Dominick Baier · Brewing Beer with Windows Azure - Windows Azure MVP Maarten Balliauw · Architectural patterns for the cloud - Windows Azure MVP Maarten Balliauw · Windows Azure Web Sites and the Power of Continuous Delivery - Windows Azure MVP Magnus Mårtensson · Advanced SQL Azure - Analyze and Optimize Performance - Windows Azure MVP Nuno Godinho · Architect your SQL Azure Databases - Windows Azure MVP Nuno Godinho   There will be a chance to get your hands on the latest Azure bits and an Azure trial account at the Hands-on Labs Day on Saturday (29th) with Brady Gaster, Magnus Mårtensson and Alan Smith there to provide guidance, and some informal and entertaining presentations. Attendance for the conference and Hands-on Labs Day is free, but please only register if you can make it, (and cancel if you cannot). Cloud-Burst 2012 event details and registration is here: http://www.azureug.se/CloudBurst2012/ Registration for Sweden Windows Azure Group Stockholm is here: swagmembership.eventbrite.com The event has been made possible by kind contributions from our sponsors, Knowit, AddSkills and Microsoft Sweden.

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• O the Agony - Merging Scrum and Waterfall

  - by John K. Hines

  If there's nothing else to know about Scrum (and Agile in general), it's this: You can't force a team to adopt Agile methods.  In all cases, the team must want to change. Well, sure, you could force a team.  But it's going to be a horrible, painful process with a huge learning curve made even steeper by the lack of training and motivation on behalf of the team.  On a completely unrelated note, I've spent the past three months working on a team that was formed by merging three separate teams.  One of these teams has been adopting and using Agile practices like Scrum since 2007, the other was in continuous bug fix mode, releasing on average one new piece of software per year using semi-Waterfall methods.  In particular, one senior developer on the Waterfall team didn't see anything in Agile but overhead. Fast forward through three months of tension, passive resistance, process pushback, and you have seven people who want to change and one who explicitly doesn't.  It took two things to make Scrum happen: The team manager took a class called "Agile Software Development using Scrum". The team lead explained the point of Agile was to reduce the workload of the senior developer, with another senior developer and the manager present. It's incredible to me how a single person can strongly influence the direction of an entire team.  Let alone if Scrum comes down as some managerial decree onto a functioning team who have no idea what it is.  Pity the fool. On the bright side, I am now an expert at drawing Visio process flows.  And I have some gentle advice for any first-level managers: If you preside over a team process change, it's beneficial to start the discussion on how the team will work as early as possible.  You should have a vision for this and guide the discussion, even if decisions are weeks away.  Don't always root for the underdog.  It's been my experience that managers who see themselves as compassionate and caring spend a great deal of time understanding and advocating for the one person on the team who feels left out.  Remember that by focusing on this one person you risk alienating the rest of the team, allow tension to build, and delay the resolution of the problem. My way would have been to decree Scrum, force all of my processes on everyone else, and use the past three months ironing out the kinks.  Which takes us all the way back to point number one. Technorati tags: Scrum Scrum Process Scrum and Waterfall

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• Brainless Backups

  - by Jesse

  I’m a software developer by trade which means to my friends and family I’m just a “computer guy”. It’s assumed that I know everything about every facet of computing from removing spyware to replacing hardware. I also can do all of this blindly over the phone or after hearing a five to ten word description of the problem over dinner ;-) In my position as CIO of my friends and families I’ve been in the unfortunate position of trying to recover music, pictures, or documents off of failed hard drives on more than one occasion. It’s not a great situation for anyone, and it’s always at these times that the importance of backups becomes so clear. Several months back a friend of mine found himself in this situation. The hard drive on his 8 year old laptop failed and took a good number of his digital photos with it. I think most folks can deal with losing some of their music and even some of their documents, but it really stings to lose pictures of past events and loved ones. After ordering a new laptop, my friend went out and bought an external hard drive so that he could start keeping a backup of his data. As fate would have it, several months later the drive in his new laptop failed and he learned the hard way that simply buying the external hard drive isn’t enough… you actually have to copy your stuff over every once in awhile! The importance of backup and recovery plans is (hopefully) well known in IT organizations. Well executed backup plans are in place, and hopefully the backup and recovery process is tested regularly. When you’re talking about users at home, however, the need for these backups is often understood far too late. Most typical users can’t be expected to remember to backup their data regularly and also don’t always have the know-how to setup automated backups. For my friends and family members in this situation I recommend tools like Dropbox, Carbonite, and Mozy. Here’s why I like them: They’re affordable: Dropbox and Mozy both have free offerings, though most people with lots of music and/or photos to backup will probably exceed the storage limitations of those free plans pretty quickly. Still, all three offer pretty affordable monthly or yearly plans. In my opinion, Carbonite’s unlimited storage plan for $50-$60 per year is the best value around. They’re easy to setup: Both Dropbox and Carbonite are very easy to get setup and start using. I’ve never used Mozy, but I imagine it’s similarly painless to get up and running. Backups are automatically “off-site”: A backup that is sitting on an external hard drive right next to your computer is great, but might not protect against flood damage, a power surge, or other disasters in that single location. These services exist “in the cloud” so to speak, helping mitigate those concerns. Granted, this kind of backup scheme requires some trust in the 3rd party to protect your data from both malicious people and disastrous events. This truly is a bit of a double edged sword, but I sleep well at night knowing that my data is being backed up and secured by a company made up of engineers that focus on the business of doing backups right. Backups are “brainless”: What I like most about services like these is that they work “automagically” in the background, watching for files to be updated and automatically backing up those changes. There’s no need to remember to plug in that external drive and copy your data over. Since starting to recommend these services to my friends and family I find myself wearing my “data recovery” hat far less often. The only way backups are effective for your standard computer user is if they’re completely automatic. Backups need to be brainless, or they just won’t work.

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• Microsoft TechDays Canada 2010

  - by David Nudelman

  John Oxley announced that TechDays is returning to Canada in more cities then ever in 2010. Vancouver – September 14/15 at the Vancouver Convention Centre Edmonton – October 5/6 at the Shaw Conference Centre Toronto – October 27/28 at the Metro Toronto Convention Centre Halifax – November 2/3 at the World Trade & Convention Centre Ottawa – November 9/10 at the Hampton Inn & Conference Centre Montreal – November 23/24 at the Palais de Congres Winnipeg – December 7/8 at the Winnipeg Convention Centre Calgary – December 14/15 at the Calgary Stampede Get all the info here Regards, David Nudelman

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• CHM Issue: The page can not be displayed

  - by Narendra Tiwari

  Some times when we access few CHM (compiled HTML) files over network share, CHM content doed not display and shows an error "The Page Can not be displayed". This may be due to a Microsoft security update installed on your machine. Here is the resolution:- ======================================================================== REGEDIT4 [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp] [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x\HHRestrictions] "MaxAllowedZone"=dword:00000001 "UrlAllowList"="" [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x\ItssRestrictions] "MaxAllowedZone"=dword:00000001 "UrlAllowList"="" ======================================================================== Put above content in a file and save as with .REG extension, then execute it from your machine. Thats it.. you should be able to view your CHM files. Reference

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• Creating Custom HTML Helpers in ASP.NET MVC

  - by Shravan

  ASP.NET MVC provides many built-in HTML Helpers.  With help of HTML Helpers we can reduce the amount of typing of HTML tags for creating a HTML page. For example we use Html.TextBox() helper method it generates html input textbox. Write the following code snippet in MVC View: <%=Html.TextBox("txtName",20)%> It generates the following html in output page: <input id="txtName" name="txtName" type="text" value="20" /> List of built-in HTML Helpers provided by ASP.NET MVC. ActionLink() - Links to an action method. BeginForm() - Marks the start of a form and links to the action method that renders the form. CheckBox() - Renders a check box. DropDownList() - Renders a drop-down list. Hidden() - Embeds information in the form that is not rendered for the user to see. ListBox() - Renders a list box. Password() - Renders a text box for entering a password. RadioButton() - Renders a radio button.TextArea() - Renders a text area (multi-line text box). TextBox () - Renders a text box. How to develop our own Custom HTML Helpers? For developing custom HTML helpers the simplest way is to write an extension method for the HtmlHelper class. See the below code, it builds a custom Image HTML Helper for generating image tag. Read The Remaing Blog Post @ http://theshravan.net/blog/creating-custom-html-helpers-in-asp-net-mvc/

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• Cannot resolve the collation conflict between "Latin1_General_CI_AS" and "SQL_Latin1_General_CP1_CI_

  - by Patrick Olurotimi Ige

  I was writing a store proc for a report and i needed some data from another server so i added a linked server to connect to this new db server. when i do a select like below its all fine select a,b,c from Server.DatabaseName.dbo.table But when i use the table in a join i get the error "Cannot resolve the collation conflict between "Latin1_General_CI_AS" and "SQL_Latin1_General_CP1_CI_AS" in the equal to operation." I did check the collation set on the 2 databases and it was actually the same and had mo idea why i'm getting the error. I later found out that you could specifically tell it to use a COLLATE Just rewrite your join like this on a.name COLLATE Latin1_General_CI_AS = eaobjname Hope that helps and saves your precious time Patrick

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• Silverlight Cream for May 25, 2010 - 2 -- #870

  - by Dave Campbell

  In this Issue: Kirupa, Matthias Shapiro(-2-, -3-), Giorgetti Alessandro, Kunal Chowdhury, Mike Snow, and Jason Zander. Shoutout: This looks like a really nice WP7 app done by a team of folks for Imagine Cup 2010: Ahead ... I hope to see some blog posts and code on this! From SilverlightCream.com, and remember you can send me a link to your post or submit at SilverlightCream.com: Control Storyboards Easily using Behaviors Kirupa is following through on a promise to discuss the Behaviors that come on-board Blend. He's starting with two to help deal with Storyboards: ControlStoryboardAction and the StoryboardCompletedTrigger. PHP, MySQL and Silverlight: The Complete Tutorial (Part 1) Matthias Shapiro has a 3-parter up on PHP, MySQL, and Silverlight -- wondered how I missed this first one until I realized they all posted in 2 days... this first post sets up the MySQL database to be used. PHP, MySQL, and Silverlight: The Complete Tutorial (Part 2) In part 2, Matthias Shapiro writes a PHP web service that grabs the data from the database and sends it in JSON format to the Silverlight app (see part 3). PHP, MySQL, and Silverlight: The Complete Tutorial (Part 3) Matthias Shapiro's part 3 is the Silverlight part that reads the JSON produced by the PHP webservice from Part 2, to provide display and edits of the data... and this whole series includes source. Silverlight: adding an IsEditing property to the DataForm Giorgetti Alessandro laments the lack of an IsEditing property in the DataForm, then goes on to demonstrate his path to a suitable workaround. Step-by-Step Command Binding in Silverlight 4 Kunal Chowdhury has a nicely-detailed post on Command Binding in Silverlight 4 and builds up a demo MVVM app in the process... source project included. Silverlight Tip of the Day #24 – Resolving Unknown Objects in VS I'm not sure I would call Mike Snow's latest Silverlight Tip 'Silverlight' ... but if you don't know it, you need to. Sample: Windows Phone 7 Example Application with Landscape Layout Whoa... check out the WP7 app Jason Zander did with landscape mode defined... you're going to want to refer back to this one... 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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• BizTalk Envelopes explained

  - by Robert Kokuti

  Recently I've been trying to get some order into an ESB-BizTalk pub/sub scenario, and decided to wrap the payload into standardized envelopes. I have used envelopes before in a 'light weight' fashion, and I found that they can be quite useful and powerful if used systematically. Here is what I learned. The Theory In my experience, Envelopes are often underutilised in a BizTalk solution, and quite often their full potential is not well understood. Here I try to simplify the theory behind the Envelopes within BizTalk.   Envelopes can be used to attach additional data to the ‘real’ data (payload). This additional data can contain all routing and processing information, and allows treating the business data as a ‘black box’, possibly compressed and/or encrypted etc. The point here is that the infrastructure does not need to know anything about the business data content, just as a post man does not need to know the letter within the envelope. BizTalk has built-in support for envelopes through the XMLDisassembler and XMLAssembler pipeline components (these are part of the XMLReceive and XMLSend default pipelines). These components, among other things, perform the following: XMLDisassembler Extracts the payload from the envelope into the Message Body Copies data from the envelope into the message context, as specified by the property schema(s) associated by the envelope schema. Typically, once the envelope is through the XMLDisassembler, the payload is submitted into the Messagebox, and the rest of the envelope data are copied into the context of the submitted message. The XMLDisassembler uses the Property Schemas, referenced by the Envelope Schema, to determine the name of the promoted Message Context element.   XMLAssembler Wraps the Message Body inside the specified envelope schema Populates the envelope values from the message context, as specified by the property schema(s) associated by the envelope schema. Notice that there are no requirements to use the receiving envelope schema when sending. The sent message can be wrapped within any suitable envelope, regardless whether the message was originally received within an envelope or not. However, by sharing Property Schemas between Envelopes, it is possible to pass values from the incoming envelope to the outgoing envelope via the Message Context. The Practice Creating the Envelope Add a new Schema to the BizTalk project:   Envelopes are defined as schemas, with the <Schema> Envelope property set to Yes, and the root node’s Body XPath property pointing to the node which contains the payload. Typically, you’d create an envelope structure similar to this: Click on the <Schema> node and set the Envelope property to Yes. Then, click on the Envelope node, and set the Body XPath property pointing to the ‘Body’ node:   The ‘Body’ node is a Child Element, and its Data Structure Type is set to xs:anyType.  This allows the Body node to carry any payload data. The XMLReceive pipeline will submit the data found in the Body node, while the XMLSend pipeline will copy the message into the Body node, before sending to the destination. Promoting Properties Once you defined the envelope, you may want to promote the envelope data (anything other than the Body) as Property Fields, in order to preserve their value in the message context. Anything not promoted will be lost when the XMLDisassembler extracts the payload from the Body. Typically, this means you promote everything in the Header node. Property promotion uses associated Property Schemas. These are special BizTalk schemas which have a flat field structure. Property Schemas define the name of the promoted values in the Message Context, by combining the Property Schema’s Namespace and the individual Field names. It is worth being systematic when it comes to naming your schemas, their namespace and type name. A coherent method will make your life easier when it comes to referencing the schemas during development, and managing subscriptions (filters) in BizTalk Administration. I developed a fairly coherent naming convention which I’ll probably share in another article. Because the property schema must be flat, I recommend creating one for each level in the envelope header hierarchy. Property schemas are very useful in passing data between incoming as outgoing envelopes. As I mentioned earlier, in/out envelopes do not have to be the same, but you can use the same property schema when you promote the outgoing envelope fields as you used for the incoming schema.  As you can reference many property schemas for field promotion, you can pick data from a variety of sources when you define your outgoing envelope. For example, the outgoing envelope can carry some of the incoming envelope’s promoted values, plus some values from the standard BizTalk message context, like the AdapterReceiveCompleteTime property from the BizTalk message-tracking properties. The values you promote for the outgoing envelope will be automatically populated from the Message Context by the XMLAssembler pipeline component. Using the Envelope Receiving Enveloped messages are automatically recognized by the XMLReceive pipeline, or any other custom pipeline which includes the XMLDisassembler component. The Body Path node will become the Message Body, while the rest of the envelope values will be added to the Message context, as defined by the Property Shemas referenced by the Envelope Schema. Sending The Send Port’s filter expression can use the promoted properties from the incoming envelope. If you want to enclose the sent message within an envelope, the Send Port XMLAssembler component must be configured with the fully qualified envelope name:   One way of obtaining the fully qualified envelope name is copy it off from the envelope schema property page: The full envelope schema name is constructed as <Name>, <Assembly> The outgoing envelope is populated by the XMLAssembler pipeline component. The Message Body is copied to the specified envelope’s Body Path node, while the rest of the envelope fields are populated from the Message Context, according to the Property Schemas associated with the Envelope Schema. That’s all for now, happy enveloping!

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• Slides and Links from SQL Azure session at BizSpark Azure Day in London

  - by Eric Nelson

  A big thanks to all who attended my two sessions on SQL Azure yesterday (29th March 2010). As promised, my slides and links from the session. SQL Azure Overview for Bizspark day View more presentations from Eric Nelson. Related Links: UK Azure Online Community – join today. UK Windows Azure Site Start working with Windows Azure SQL Azure maximum database size rises from 10GB to 50GB in June TCO and ROI calculator for Windows Azure SQL Azure Migration Wizard

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• Silverlight Cream for March 10, 2011 -- #1058

  - by Dave Campbell

  In this Issue: Ian T. Lackey, Peter Kuhn, WindowsPhoneGeek(-2-), Jesse Liberty(-2-), Martin Krüger, John Papa, Jeremy Likness, Karl Shifflett, and Colin Eberhardt. Above the Fold: Silverlight: "Silverlight TV 65: 3D Graphics" John Papa WP7: "Developing a Windows Phone 7 Jump List Control" Colin Eberhardt Shoutouts: Telerik announced a special sale on their RadControls for WP7... check it out: RadControls for Windows Phone 7 - on Sale from March 16th at a Special Promo Price! From SilverlightCream.com: Prism BootStrapper Load ModuleCatalog Ansyc Ian T. Lackey has a post up about reading the module catalog for Prism from an XML file asynchronously... fun stuff... this is how we kick-started our app... XNA for Silverlight developers: Part 6 - Input (accelerometer) Peter Kuhn has Part 6 of his XNA for Silverlight devs up at SilverlightShow. This post is on the use of the accelerometer... some great diagrams and explanations of it's use along with some code to play with... including a 'problems and pitfalls' section, and some good external links. Getting Started with Unit Testing in Silverlight for WP7 WindowsPhoneGeek has an introduction to Unit Testing in general, and then moves into Unit Testing in Silverlight for WP7, providing 3 options with links to the materials and code demonstrating the concepts. Using DockPanel in WP7 Responding to reader's questions, WindowsPhoneGeek's next post is on the DockPanel from the Silverlight Toolkit, and using it in WP7... defined declaratively and in code. Reactive Extensions–More About Chaining Jesse Liberty has post number 10 on Rx up and is a follow-on to the last one on Chaining. This time he exercises the chaining aspect of SelectMany. Yet Another Podcast #26–Walt Ritscher In his next post, Jesse Liberty has his 26th 'Yet Another Podcast' up and is chatting with my friend Walt Ritscher. If you don't know who Walt is, check out the links Jesse has on the post... I'm sure you've crossed paths. How to: Create A half square from a regular polygon (triangle) Martin Krüger demonstrates the exact placement of a half-square (isosceles right triangle), formed with a regular polygon in Blend... this is much more involved than I've made it sound... check out his post. Silverlight TV 65: 3D Graphics John Papa has Silverlight TV number 65 up and it's all about the 3D graphics stuff we saw at the Firestarter. John is talking with Danny Riddel, the CEO of Archetype, the company that built the awesome 3D demo we all gushed over. Jounce Part 12: Providing History-Based Back Navigation Jeremy Likness has part 12 of his Jounce exploration up... and discussing the stack of navigated pages that Jounce retains and providing a 'go back' functionality... and provides a good example of using it all. Prism 4 Region Navigation with Silverlight Frame Navigation and Unity Karl Shifflett has a post for all us Prism afficianados... Prism, Unity, and the Silverlight Frame Navigation framework. Some great external links for 'required reading' too. Developing a Windows Phone 7 Jump List Control Colin Eberhardt has an awesome tutorial up for creating a JumpList control for WP7... what a bunch of effort... this is a step-by-step description of designing the control he built and blogged about a while back... and it's still cool! 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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• Free E-book on NHibernate from Syncfusion

  - by TATWORTH

  Originally posted on: http://geekswithblogs.net/TATWORTH/archive/2014/08/07/free-e-book-on-nhibernate-from-syncfusion.aspxSyncfusion are providing a free E-Book on NHibernate at http://www.syncfusion.com/resources/techportal/ebooks/nhibernate?utm_medium=edm “Master the intricacies of NHibernate, an established and powerful Object/Relational Mapper (ORM) in NHibernate Succinctly. Let author Ricardo Peres guide you toward a fuller understanding of one of the oldest and most flexible ORMs available”

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• Craftsmanship Tour: Day 2 Obtiva

  - by Liam McLennan

  I like Chicago. It is a great city for travellers. From the moment I got off the plane at O’Hare everything was easy. I took the train to ‘the Loop’ and walked around the corner to my hotel, Hotel Blake on Dearborn St. Sadly, the elevated train lines in downtown Chicago remind me of ‘Shall We Dance’. Hotel Blake is excellent (except for the breakfast) and the concierge directed me to a pizza place called Lou Malnati's for Chicago style deep-dish pizza. Lou Malnati’s would be a great place to go with a group of friends. I felt strange dining there by myself, but the food and service were excellent. As usual in the United States the portion was so large that I could not finish it, but oh how I tried. Dave Hoover, who invited me to Obtiva for the day, had asked me to arrive at 9:45am. I was up early and had some time to kill so I stopped at the Willis Tower, since it was on my way to the office. Willis Tower is 1,451 feet (442 m) tall and has an observation deck at the top. Around the observation deck are a set of acrylic boxes, protruding from the side of the building. Brave soles can walk out on the perspex and look between their feet all the way down to the street. It is unnerving. Obtiva is a progressive, craftsmanship-focused software development company in downtown Chicago. Dave even wrote a book, Apprenticeship Patterns, that provides a catalogue of patterns to assist aspiring software craftsmen to achieve their goals. I spent the morning working in Obtiva’s software studio, an open xp-style office that houses Obtiva’s in-house development team. For lunch Dave Hoover, Corey Haines, Cory Foy and I went to a local Greek restaurant (not Dancing Zorbas). Dave, Corey and Cory are three smart and motivated guys and I found their ideas enlightening. It was especially great to chat with Corey Haines since he was the inspiration for my craftsmanship tour in the first place. After lunch I recorded a brief interview with Dave. Unfortunately, the battery in my camera went flat so I missed recording some interesting stuff. Interview with Dave Hoover In the evening Obtiva hosted an rspec hackfest with David Chelimsky and others. This was an excellent opportunity to be around some of the very best ruby programmers. At 10pm I went back to my hotel to get some rest before my train north the next morning.

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• Book &ldquo;Team Foundation Server 2012 Starter&rdquo; published

  - by terje

  During the summer and fall this year, me and my colleague Jakob Ehn has worked together on a book project that has now finally hit the stores! The title of the book is Team Foundation Server 2012 Starter and is published by Packt Publishing. Get it from http://www.packtpub.com/team-foundation-server-2012-starter/book or from Amazon http://www.amazon.com/dp/1849688389                     The book is part of a concept that Packt have with starter-books, intended for people new to Team Foundation Server 2012 and who want a quick guideline to get it up and working.  It covers the fundamentals, from installing and configuring it, and how to use it with source control, work items and builds. It is done as a step-by-step guide, but also includes best practices advice in the different areas. It covers the use of both the on-premises and the TFS Services version. It also has a list of links and references in the end to the most relevant Visual Studio 2012 ALM sites. Our good friend and fellow ALM MVP Mathias Olausson have done the review of the book, thanks again Mathias! We hope the book fills the gap between the different online guide sites and the more advanced books that are out. Book Description Your quick start guide to TFS 2012, top features, and best practices with hands on examples Overview Install TFS 2012 from scratch Get up and running with your first project Streamline release cycles for maximum productivity In Detail Team Foundation Server 2012 is Microsoft's leading ALM tool, integrating source control, work item and process handling, build automation, and testing. This practical "Team Foundation Server 2012 Starter Guide" will provide you with clear step-by-step exercises covering all major aspects of the product. This is essential reading for anyone wishing to set up, organize, and use TFS server. This hands-on guide looks at the top features in Team Foundation Server 2012, starting with a quick installation guide and then moving into using it for your software development projects. Manage your team projects with Team Explorer, one of the many new features for 2012. Covering all the main features in source control to help you work more efficiently, including tools for branching and merging, we will delve into the Agile Planning Tools for planning your product and sprint backlogs. Learn to set up build automation, allowing your team to become faster, more streamlined, and ultimately more productive with this "Team Foundation Server 2012 Starter Guide". What you will learn from this book Install TFS 2012 on premise Access TFS Services in the cloud Quickly get started with a new project with product backlogs, source control, and build automation Work efficiently with source control using the top features Understand how the tools for branching and merging in TFS 2012 help you isolate work and teams Learn about the existing process templates, such as Visual Studio Scrum 2.0 Manage your product and sprint backlogs using the Agile planning tools Approach This Starter guide is a short, sharp introduction to Team Foundation Server 2012, covering everything you need to get up and running. Who this book is written for If you are a developer, project lead, tester, or IT administrator working with Team Foundation Server 2012 this guide will get you up to speed quickly and with minimal effort.

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• Going to Tech*Ed 2010

  - by Nikita Polyakov

  After years of one night community and volunteering tasks; and even running cool events like ]inbetween[ weekend, I finally get to go to the actual event! And this time it’s not in Orlando – it’s in New Orleans - which is also exciting! I will be attending many Windows Phone 7 sessions. And will hover over the Windows Phone booths. I am also extremely excited about this short exchange I had on twitter with the brand new Windows Phone Partner Community account: @wppartner #WindwosPhone 7 Enterprise story is what we are all waiting to hear :) #wp7dev 7:51 PM Jun 1st via TweetDeck in reply to wppartner @NikitaP We'll definitely be covering that at @WPCDC but we'll also be talking about it at @TechEd_NA next week! about 4 hours ago via CoTweet in reply to NikitaP As you might know I also love Microsoft Expression Blend and SketchFlow. I will be hanging out at the Microsoft Expression TLC [Technical Learning Center] booths in Expo Hall during these times: Day Start Finish 7-Jun 10:30 AM 12:30 PM 7-Jun 7:30 PM 9:00 PM 8-Jun 2:45 PM 5:00 PM 9-Jun 2:45 PM 5:00 PM 10-Jun 12:15 PM 3:00 PM   Feel free to find me and chat me up. I’ll be twittering under @NikitaP, if you are in Florida dev community use #teched_fl hash tag. If you are going and you have a Windows Phone 6.5, iPhone/ipad, Android or a Vista/Win7 laptop with you, grab this: Kevin Wolf’s TechEd 2010 Schedule and Twitter Tool – One App, 5 Different Platforms in one word: Aaaaaaamazing!

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• SharePoint Saturday Charlotte 2010 Recap, Slides and Photos

  - by Brian Jackett

  This past weekend I attended SharePoint Saturday Charlotte (SPSCLT) in Charlotte, North Carolina.  For those unfamiliar, SharePoint Saturday is a community driven event where various speakers gather to present at a FREE conference on all topics related to SharePoint.  This made my fourth SharePoint Saturday attended and third I’ve spoken at.  The event was very well organized, attended, and a pleasure to be a part of along with many other great speakers.     At SharePoint Saturday Charlotte I had the opportunity to give two presentations.  First was “The Power of PowerShell + SharePoint 2007” and second was a new one “Managing SharePoint 2010 Farms with PowerShell.”  I want to thank everyone who attended either of my sessions and for all of the feedback given.  Below you will find links to my slides, demo scripts, and pictures taken throughout the event.  If anyone has any questions from the slides or scripts feel free to drop me a line.   Pictures SharePoint Saturday Charlotte Apr '10 Pictures on Facebook (recommend these with comments and tagging)   View Full Album   Slides, Scripts, and Rating Links SharePoint Saturday Charlotte Apr '10 Slides and Demo Scripts SpeakerRate: The Power of PowerShell + SharePoint 2007 SpeakerRate: Managing SharePoint 2010 Farms with PowerShell   Conclusion     Big thanks out to Brian Gough (@bkgough), Dan Lewis (@sharepointcomic) and all of the other organizers of this event.  Also a big thanks out to the other speakers and sponsors (too many to list) who made the event possible.  Lastly thanks to my Sogeti coworker Kelly Jones (@kellydjones) for picking me up from the airport and a ride back to Columbus.  I hope everyone that attended got something out of the event and will continue to grow the SharePoint community.  I’m on a break from conferences for a few weeks and then have 3 more back to back weekends in May, blog posts announcing those coming later.  Enjoy the slides, scripts, and pictures.         -Frog Out

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• Silverlight Cream for April 19, 2010 -- #841

  - by Dave Campbell

  In this Issue: Michael Washington, Jeremy Likness, Giorgetti Alessandro, Antoni Dol, Mike Taulty, and Braulio Diez. Shoutout: Bart Czernicki lists compelling reasons to use Silverlight 4 for LOB apps: Silverlight 4 - What is New for Business Intelligence Scenarios From SilverlightCream.com: Silverlight Advanced MVVM Video Player After the initial posting on his Simple MVVM Video player, Michael Washington got some feedback and decided to do a part 2 demonstrating exactly how easy it is to customize... great tutorial and all the code. Model-View-ViewModel (MVVM) Explained Jeremy Likness has a post up that begins "The purpose of this post is to provide an introduction to the Model-View-ViewModel (MVVM) pattern." -- 'nuff said... If you're not there yet, get there now :) Castle Windsor – Silverlight 4 binaries Giorgetti Alessandro has produced workable Castle Windsor binaries for Silverlight 4. No Unit Tests at this point, but read the post for that information. Silverlight Togglebutton Push Pin Style with IsoStore Antoni Dol has a very nice ToggleButton redone as a pushpin for pinning an app, plus it saves the pinned information to Isolated Storage ... all with source! Silverlight and Xml Binding Mike Taulty fleshes out a sketchy idea he has surrounding databinding Silverlight to XML data by using the ability to databind to string indexers and XPath support. WinToolbar Silverlight widget available on Codeplex Braulio Diez announced a Toolbar library that he and Sebastian Stehlehave posted on CodePlex that looks awesome... you may as well just go get it now, you're going to want to! 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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• C#/.NET Little Wonders: The ConcurrentDictionary

  - by James Michael Hare

  Once again we consider some of the lesser known classes and keywords of C#.  In this series of posts, we will discuss how the concurrent collections have been developed to help alleviate these multi-threading concerns.  Last week’s post began with a general introduction and discussed the ConcurrentStack<T> and ConcurrentQueue<T>.  Today's post discusses the ConcurrentDictionary<T> (originally I had intended to discuss ConcurrentBag this week as well, but ConcurrentDictionary had enough information to create a very full post on its own!).  Finally next week, we shall close with a discussion of the ConcurrentBag<T> and BlockingCollection<T>. For more of the "Little Wonders" posts, see the index here. Recap As you'll recall from the previous post, the original collections were object-based containers that accomplished synchronization through a Synchronized member.  While these were convenient because you didn't have to worry about writing your own synchronization logic, they were a bit too finely grained and if you needed to perform multiple operations under one lock, the automatic synchronization didn't buy much. With the advent of .NET 2.0, the original collections were succeeded by the generic collections which are fully type-safe, but eschew automatic synchronization.  This cuts both ways in that you have a lot more control as a developer over when and how fine-grained you want to synchronize, but on the other hand if you just want simple synchronization it creates more work. With .NET 4.0, we get the best of both worlds in generic collections.  A new breed of collections was born called the concurrent collections in the System.Collections.Concurrent namespace.  These amazing collections are fine-tuned to have best overall performance for situations requiring concurrent access.  They are not meant to replace the generic collections, but to simply be an alternative to creating your own locking mechanisms. Among those concurrent collections were the ConcurrentStack<T> and ConcurrentQueue<T> which provide classic LIFO and FIFO collections with a concurrent twist.  As we saw, some of the traditional methods that required calls to be made in a certain order (like checking for not IsEmpty before calling Pop()) were replaced in favor of an umbrella operation that combined both under one lock (like TryPop()). Now, let's take a look at the next in our series of concurrent collections!For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this wonderful whitepaper by the Microsoft Parallel Computing Platform team here. ConcurrentDictionary – the fully thread-safe dictionary The ConcurrentDictionary<TKey,TValue> is the thread-safe counterpart to the generic Dictionary<TKey, TValue> collection.  Obviously, both are designed for quick – O(1) – lookups of data based on a key.  If you think of algorithms where you need lightning fast lookups of data and don’t care whether the data is maintained in any particular ordering or not, the unsorted dictionaries are generally the best way to go. Note: as a side note, there are sorted implementations of IDictionary, namely SortedDictionary and SortedList which are stored as an ordered tree and a ordered list respectively.  While these are not as fast as the non-sorted dictionaries – they are O(log2 n) – they are a great combination of both speed and ordering -- and still greatly outperform a linear search. Now, once again keep in mind that if all you need to do is load a collection once and then allow multi-threaded reading you do not need any locking.  Examples of this tend to be situations where you load a lookup or translation table once at program start, then keep it in memory for read-only reference.  In such cases locking is completely non-productive. However, most of the time when we need a concurrent dictionary we are interleaving both reads and updates.  This is where the ConcurrentDictionary really shines!  It achieves its thread-safety with no common lock to improve efficiency.  It actually uses a series of locks to provide concurrent updates, and has lockless reads!  This means that the ConcurrentDictionary gets even more efficient the higher the ratio of reads-to-writes you have. ConcurrentDictionary and Dictionary differences For the most part, the ConcurrentDictionary<TKey,TValue> behaves like it’s Dictionary<TKey,TValue> counterpart with a few differences.  Some notable examples of which are: Add() does not exist in the concurrent dictionary. This means you must use TryAdd(), AddOrUpdate(), or GetOrAdd().  It also means that you can’t use a collection initializer with the concurrent dictionary. TryAdd() replaced Add() to attempt atomic, safe adds. Because Add() only succeeds if the item doesn’t already exist, we need an atomic operation to check if the item exists, and if not add it while still under an atomic lock. TryUpdate() was added to attempt atomic, safe updates. If we want to update an item, we must make sure it exists first and that the original value is what we expected it to be.  If all these are true, we can update the item under one atomic step. TryRemove() was added to attempt atomic, safe removes. To safely attempt to remove a value we need to see if the key exists first, this checks for existence and removes under an atomic lock. AddOrUpdate() was added to attempt an thread-safe “upsert”. There are many times where you want to insert into a dictionary if the key doesn’t exist, or update the value if it does.  This allows you to make a thread-safe add-or-update. GetOrAdd() was added to attempt an thread-safe query/insert. Sometimes, you want to query for whether an item exists in the cache, and if it doesn’t insert a starting value for it.  This allows you to get the value if it exists and insert if not. Count, Keys, Values properties take a snapshot of the dictionary. Accessing these properties may interfere with add and update performance and should be used with caution. ToArray() returns a static snapshot of the dictionary. That is, the dictionary is locked, and then copied to an array as a O(n) operation.  GetEnumerator() is thread-safe and efficient, but allows dirty reads. Because reads require no locking, you can safely iterate over the contents of the dictionary.  The only downside is that, depending on timing, you may get dirty reads. Dirty reads during iteration The last point on GetEnumerator() bears some explanation.  Picture a scenario in which you call GetEnumerator() (or iterate using a foreach, etc.) and then, during that iteration the dictionary gets updated.  This may not sound like a big deal, but it can lead to inconsistent results if used incorrectly.  The problem is that items you already iterated over that are updated a split second after don’t show the update, but items that you iterate over that were updated a split second before do show the update.  Thus you may get a combination of items that are “stale” because you iterated before the update, and “fresh” because they were updated after GetEnumerator() but before the iteration reached them. Let’s illustrate with an example, let’s say you load up a concurrent dictionary like this: 1: // load up a dictionary. 2: var dictionary = new ConcurrentDictionary<string, int>(); 3:  4: dictionary["A"] = 1; 5: dictionary["B"] = 2; 6: dictionary["C"] = 3; 7: dictionary["D"] = 4; 8: dictionary["E"] = 5; 9: dictionary["F"] = 6; Then you have one task (using the wonderful TPL!) to iterate using dirty reads: 1: // attempt iteration in a separate thread 2: var iterationTask = new Task(() => 3: { 4: // iterates using a dirty read 5: foreach (var pair in dictionary) 6: { 7: Console.WriteLine(pair.Key + ":" + pair.Value); 8: } 9: }); And one task to attempt updates in a separate thread (probably): 1: // attempt updates in a separate thread 2: var updateTask = new Task(() => 3: { 4: // iterates, and updates the value by one 5: foreach (var pair in dictionary) 6: { 7: dictionary[pair.Key] = pair.Value + 1; 8: } 9: }); Now that we’ve done this, we can fire up both tasks and wait for them to complete: 1: // start both tasks 2: updateTask.Start(); 3: iterationTask.Start(); 4:  5: // wait for both to complete. 6: Task.WaitAll(updateTask, iterationTask); Now, if I you didn’t know about the dirty reads, you may have expected to see the iteration before the updates (such as A:1, B:2, C:3, D:4, E:5, F:6).  However, because the reads are dirty, we will quite possibly get a combination of some updated, some original.  My own run netted this result: 1: F:6 2: E:6 3: D:5 4: C:4 5: B:3 6: A:2 Note that, of course, iteration is not in order because ConcurrentDictionary, like Dictionary, is unordered.  Also note that both E and F show the value 6.  This is because the output task reached F before the update, but the updates for the rest of the items occurred before their output (probably because console output is very slow, comparatively). If we want to always guarantee that we will get a consistent snapshot to iterate over (that is, at the point we ask for it we see precisely what is in the dictionary and no subsequent updates during iteration), we should iterate over a call to ToArray() instead: 1: // attempt iteration in a separate thread 2: var iterationTask = new Task(() => 3: { 4: // iterates using a dirty read 5: foreach (var pair in dictionary.ToArray()) 6: { 7: Console.WriteLine(pair.Key + ":" + pair.Value); 8: } 9: }); The atomic Try…() methods As you can imagine TryAdd() and TryRemove() have few surprises.  Both first check the existence of the item to determine if it can be added or removed based on whether or not the key currently exists in the dictionary: 1: // try add attempts an add and returns false if it already exists 2: if (dictionary.TryAdd("G", 7)) 3: Console.WriteLine("G did not exist, now inserted with 7"); 4: else 5: Console.WriteLine("G already existed, insert failed."); TryRemove() also has the virtue of returning the value portion of the removed entry matching the given key: 1: // attempt to remove the value, if it exists it is removed and the original is returned 2: int removedValue; 3: if (dictionary.TryRemove("C", out removedValue)) 4: Console.WriteLine("Removed C and its value was " + removedValue); 5: else 6: Console.WriteLine("C did not exist, remove failed."); Now TryUpdate() is an interesting creature.  You might think from it’s name that TryUpdate() first checks for an item’s existence, and then updates if the item exists, otherwise it returns false.  Well, note quite... It turns out when you call TryUpdate() on a concurrent dictionary, you pass it not only the new value you want it to have, but also the value you expected it to have before the update.  If the item exists in the dictionary, and it has the value you expected, it will update it to the new value atomically and return true.  If the item is not in the dictionary or does not have the value you expected, it is not modified and false is returned. 1: // attempt to update the value, if it exists and if it has the expected original value 2: if (dictionary.TryUpdate("G", 42, 7)) 3: Console.WriteLine("G existed and was 7, now it's 42."); 4: else 5: Console.WriteLine("G either didn't exist, or wasn't 7."); The composite Add methods The ConcurrentDictionary also has composite add methods that can be used to perform updates and gets, with an add if the item is not existing at the time of the update or get. The first of these, AddOrUpdate(), allows you to add a new item to the dictionary if it doesn’t exist, or update the existing item if it does.  For example, let’s say you are creating a dictionary of counts of stock ticker symbols you’ve subscribed to from a market data feed: 1: public sealed class SubscriptionManager 2: { 3: private readonly ConcurrentDictionary<string, int> _subscriptions = new ConcurrentDictionary<string, int>(); 4:  5: // adds a new subscription, or increments the count of the existing one. 6: public void AddSubscription(string tickerKey) 7: { 8: // add a new subscription with count of 1, or update existing count by 1 if exists 9: var resultCount = _subscriptions.AddOrUpdate(tickerKey, 1, (symbol, count) => count + 1); 10:  11: // now check the result to see if we just incremented the count, or inserted first count 12: if (resultCount == 1) 13: { 14: // subscribe to symbol... 15: } 16: } 17: } Notice the update value factory Func delegate.  If the key does not exist in the dictionary, the add value is used (in this case 1 representing the first subscription for this symbol), but if the key already exists, it passes the key and current value to the update delegate which computes the new value to be stored in the dictionary.  The return result of this operation is the value used (in our case: 1 if added, existing value + 1 if updated). Likewise, the GetOrAdd() allows you to attempt to retrieve a value from the dictionary, and if the value does not currently exist in the dictionary it will insert a value.  This can be handy in cases where perhaps you wish to cache data, and thus you would query the cache to see if the item exists, and if it doesn’t you would put the item into the cache for the first time: 1: public sealed class PriceCache 2: { 3: private readonly ConcurrentDictionary<string, double> _cache = new ConcurrentDictionary<string, double>(); 4:  5: // adds a new subscription, or increments the count of the existing one. 6: public double QueryPrice(string tickerKey) 7: { 8: // check for the price in the cache, if it doesn't exist it will call the delegate to create value. 9: return _cache.GetOrAdd(tickerKey, symbol => GetCurrentPrice(symbol)); 10: } 11:  12: private double GetCurrentPrice(string tickerKey) 13: { 14: // do code to calculate actual true price. 15: } 16: } There are other variations of these two methods which vary whether a value is provided or a factory delegate, but otherwise they work much the same. Oddities with the composite Add methods The AddOrUpdate() and GetOrAdd() methods are totally thread-safe, on this you may rely, but they are not atomic.  It is important to note that the methods that use delegates execute those delegates outside of the lock.  This was done intentionally so that a user delegate (of which the ConcurrentDictionary has no control of course) does not take too long and lock out other threads. This is not necessarily an issue, per se, but it is something you must consider in your design.  The main thing to consider is that your delegate may get called to generate an item, but that item may not be the one returned!  Consider this scenario: A calls GetOrAdd and sees that the key does not currently exist, so it calls the delegate.  Now thread B also calls GetOrAdd and also sees that the key does not currently exist, and for whatever reason in this race condition it’s delegate completes first and it adds its new value to the dictionary.  Now A is done and goes to get the lock, and now sees that the item now exists.  In this case even though it called the delegate to create the item, it will pitch it because an item arrived between the time it attempted to create one and it attempted to add it. Let’s illustrate, assume this totally contrived example program which has a dictionary of char to int.  And in this dictionary we want to store a char and it’s ordinal (that is, A = 1, B = 2, etc).  So for our value generator, we will simply increment the previous value in a thread-safe way (perhaps using Interlocked): 1: public static class Program 2: { 3: private static int _nextNumber = 0; 4:  5: // the holder of the char to ordinal 6: private static ConcurrentDictionary<char, int> _dictionary 7: = new ConcurrentDictionary<char, int>(); 8:  9: // get the next id value 10: public static int NextId 11: { 12: get { return Interlocked.Increment(ref _nextNumber); } 13: } Then, we add a method that will perform our insert: 1: public static void Inserter() 2: { 3: for (int i = 0; i < 26; i++) 4: { 5: _dictionary.GetOrAdd((char)('A' + i), key => NextId); 6: } 7: } Finally, we run our test by starting two tasks to do this work and get the results… 1: public static void Main() 2: { 3: // 3 tasks attempting to get/insert 4: var tasks = new List<Task> 5: { 6: new Task(Inserter), 7: new Task(Inserter) 8: }; 9:  10: tasks.ForEach(t => t.Start()); 11: Task.WaitAll(tasks.ToArray()); 12:  13: foreach (var pair in _dictionary.OrderBy(p => p.Key)) 14: { 15: Console.WriteLine(pair.Key + ":" + pair.Value); 16: } 17: } If you run this with only one task, you get the expected A:1, B:2, ..., Z:26.  But running this in parallel you will get something a bit more complex.  My run netted these results: 1: A:1 2: B:3 3: C:4 4: D:5 5: E:6 6: F:7 7: G:8 8: H:9 9: I:10 10: J:11 11: K:12 12: L:13 13: M:14 14: N:15 15: O:16 16: P:17 17: Q:18 18: R:19 19: S:20 20: T:21 21: U:22 22: V:23 23: W:24 24: X:25 25: Y:26 26: Z:27 Notice that B is 3?  This is most likely because both threads attempted to call GetOrAdd() at roughly the same time and both saw that B did not exist, thus they both called the generator and one thread got back 2 and the other got back 3.  However, only one of those threads can get the lock at a time for the actual insert, and thus the one that generated the 3 won and the 3 was inserted and the 2 got discarded.  This is why on these methods your factory delegates should be careful not to have any logic that would be unsafe if the value they generate will be pitched in favor of another item generated at roughly the same time.  As such, it is probably a good idea to keep those generators as stateless as possible. Summary The ConcurrentDictionary is a very efficient and thread-safe version of the Dictionary generic collection.  It has all the benefits of type-safety that it’s generic collection counterpart does, and in addition is extremely efficient especially when there are more reads than writes concurrently. Tweet Technorati Tags: C#, .NET, Concurrent Collections, Collections, Little Wonders, Black Rabbit Coder,James Michael Hare

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