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  • The Proper Use of the VM Role in Windows Azure

    - by BuckWoody
    At the Professional Developer’s Conference (PDC) in 2010 we announced an addition to the Computational Roles in Windows Azure, called the VM Role. This new feature allows a great deal of control over the applications you write, but some have confused it with our full infrastructure offering in Windows Hyper-V. There is a proper architecture pattern for both of them. Virtualization Virtualization is the process of taking all of the hardware of a physical computer and replicating it in software alone. This means that a single computer can “host” or run several “virtual” computers. These virtual computers can run anywhere - including at a vendor’s location. Some companies refer to this as Cloud Computing since the hardware is operated and maintained elsewhere. IaaS The more detailed definition of this type of computing is called Infrastructure as a Service (Iaas) since it removes the need for you to maintain hardware at your organization. The operating system, drivers, and all the other software required to run an application are still under your control and your responsibility to license, patch, and scale. Microsoft has an offering in this space called Hyper-V, that runs on the Windows operating system. Combined with a hardware hosting vendor and the System Center software to create and deploy Virtual Machines (a process referred to as provisioning), you can create a Cloud environment with full control over all aspects of the machine, including multiple operating systems if you like. Hosting machines and provisioning them at your own buildings is sometimes called a Private Cloud, and hosting them somewhere else is often called a Public Cloud. State-ful and Stateless Programming This paradigm does not create a new, scalable way of computing. It simply moves the hardware away. The reason is that when you limit the Cloud efforts to a Virtual Machine, you are in effect limiting the computing resources to what that single system can provide. This is because much of the software developed in this environment maintains “state” - and that requires a little explanation. “State-ful programming” means that all parts of the computing environment stay connected to each other throughout a compute cycle. The system expects the memory, CPU, storage and network to remain in the same state from the beginning of the process to the end. You can think of this as a telephone conversation - you expect that the other person picks up the phone, listens to you, and talks back all in a single unit of time. In “Stateless” computing the system is designed to allow the different parts of the code to run independently of each other. You can think of this like an e-mail exchange. You compose an e-mail from your system (it has the state when you’re doing that) and then you walk away for a bit to make some coffee. A few minutes later you click the “send” button (the network has the state) and you go to a meeting. The server receives the message and stores it on a mail program’s database (the mail server has the state now) and continues working on other mail. Finally, the other party logs on to their mail client and reads the mail (the other user has the state) and responds to it and so on. These events might be separated by milliseconds or even days, but the system continues to operate. The entire process doesn’t maintain the state, each component does. This is the exact concept behind coding for Windows Azure. The stateless programming model allows amazing rates of scale, since the message (think of the e-mail) can be broken apart by multiple programs and worked on in parallel (like when the e-mail goes to hundreds of users), and only the order of re-assembling the work is important to consider. For the exact same reason, if the system makes copies of those running programs as Windows Azure does, you have built-in redundancy and recovery. It’s just built into the design. The Difference Between Infrastructure Designs and Platform Designs When you simply take a physical server running software and virtualize it either privately or publicly, you haven’t done anything to allow the code to scale or have recovery. That all has to be handled by adding more code and more Virtual Machines that have a slight lag in maintaining the running state of the system. Add more machines and you get more lag, so the scale is limited. This is the primary limitation with IaaS. It’s also not as easy to deploy these VM’s, and more importantly, you’re often charged on a longer basis to remove them. your agility in IaaS is more limited. Windows Azure is a Platform - meaning that you get objects you can code against. The code you write runs on multiple nodes with multiple copies, and it all works because of the magic of Stateless programming. you don’t worry, or even care, about what is running underneath. It could be Windows (and it is in fact a type of Windows Server), Linux, or anything else - but that' isn’t what you want to manage, monitor, maintain or license. You don’t want to deploy an operating system - you want to deploy an application. You want your code to run, and you don’t care how it does that. Another benefit to PaaS is that you can ask for hundreds or thousands of new nodes of computing power - there’s no provisioning, it just happens. And you can stop using them quicker - and the base code for your application does not have to change to make this happen. Windows Azure Roles and Their Use If you need your code to have a user interface, in Visual Studio you add a Web Role to your project, and if the code needs to do work that doesn’t involve a user interface you can add a Worker Role. They are just containers that act a certain way. I’ll provide more detail on those later. Note: That’s a general description, so it’s not entirely accurate, but it’s accurate enough for this discussion. So now we’re back to that VM Role. Because of the name, some have mistakenly thought that you can take a Virtual Machine running, say Linux, and deploy it to Windows Azure using this Role. But you can’t. That’s not what it is designed for at all. If you do need that kind of deployment, you should look into Hyper-V and System Center to create the Private or Public Infrastructure as a Service. What the VM Role is actually designed to do is to allow you to have a great deal of control over the system where your code will run. Let’s take an example. You’ve heard about Windows Azure, and Platform programming. You’re convinced it’s the right way to code. But you have a lot of things you’ve written in another way at your company. Re-writing all of your code to take advantage of Windows Azure will take a long time. Or perhaps you have a certain version of Apache Web Server that you need for your code to work. In both cases, you think you can (or already have) code the the software to be “Stateless”, you just need more control over the place where the code runs. That’s the place where a VM Role makes sense. Recap Virtualizing servers alone has limitations of scale, availability and recovery. Microsoft’s offering in this area is Hyper-V and System Center, not the VM Role. The VM Role is still used for running Stateless code, just like the Web and Worker Roles, with the exception that it allows you more control over the environment of where that code runs.

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  • MSCC: Scripting - Administrator's­ toolbox of magic...

    Finally, we made it to have our April meetup - in May. The most obvious explanation is the increased amount of open source and IT activities that either the MSCC, the Linux User Group of Mauritius (LUGM), or the University of Mauritius Student's Computer Club is organising. It's absolutely incredible to see the recent hype of events here on the island. And I'm loving it! Unfortunately, we also had to deal with arranging for a location this time. It was kind of an odyssey as my requests (and phone calls) haven't been answered, even though I tried it several times - well, kind of disappointing and I have to look into that for future gatherings. In my opinion, it is essential that two parameters of a community meeting are fixed as early as possible: Location, and Date and time You can't just change one or both on the very last minute. Well, this time we had to do it due to unforeseen reasons, and I apologise to any MSCC member which couldn't make it to our April meetup. Okay, lesson learned but now back to the actual meetup report ... Shortly after the meeting I placed the following statement as my first impression: "Spontaneous and improvised :) No, seriously, Ish and Dan had well prepared presentations on shell scripting, mainly focused towards Bourne Again Shell (bash), and the pros and cons of scripting versus actually writing something in a decent programming language. I thought that I could cut myself out of the equation but the demand for information about PowerShell was higher than expected..." Well, it turned out that the interest in Windows PowerShell was high, as I even got a couple of questions on it via social media networks during the evening. I also like to mention that the number of attendees went back to what I would call a "standard" number of participation. This time there were 12 craftsmen, but again a good number of First Timers. Reactions of other attendees Here are some impressions and feedback from our participants: "Enjoyed the bash and powershell (linux / windows) presentations ..." -- Nadim on event comments "He [Daniel] also showed us some syntax loopholes in Bash that could leave someone with bad code." -- Ish on MSCC – Let's talk about Scripting   Glad to see a couple of first time attendees, especially students from the university itself. Some details on the presentations MSCC: First time visit at the University of Mauritius - Phase II Engineering Tower, room 2.9 Gimme some love ... bash and other shells Ish gave a great introduction into shell scripting as he spoke about existing shell environments and a little bit about their history. Furthermore, he talked about various built-in commands, the use of coreutils, the ability to daisy-chain multiple commands using pipes, the importance of the standard I/O streams and their file descriptors in advanced scripting techniques. Combined with a couple of sample statements in the Linux terminal on Ubuntu 14.04 machine it was a solid presentation. Have a closer look at his slides - published on his blog on MSCC – Let's talk about Scripting. Oddities of scripting After the brief introduction into bash it was Daniel's turn to highlight a good number of oddities when working with shell scripts. First of all, it should be clear that scripting is not supposed for any kind of implementations in terms of software but simply to automate administrative procedures and to simplify routine jobs on a system. One of the cool oddities that he mentioned is that everything (!) in a shell is represented by strings; there are no other types like integer, float, date-time, etc. that you'd like to use in a full-fledged programming language. Let's have a look at his sample:  more to come... What's the output? As a conclusion, Daniel suggests that shell scripting should be limited but not restricted to automatic repetitive command stacks and batch jobs, startup wrapper for applications in order to set up the execution environment, and other not too sophisticated jobs. But as soon as it might involve a little bit more logic or you might rely on performance it's better to write an application in Ruby, Python, or Perl (among others of course). This is also enables the possibility to test your code properly. MSCC: Ish talking about Bourne Again Shell (bash) and shell scripting to automate regular tasks MSCC: Daniel gives an overview about the pros and cons of shell scripting versus programming MSCC: PowerShell as your scripting solution on Windows operating systems The path of the Enlightened is long ... and tough. Honestly, even though PowerShell was mentioned without any further details on the meetup's agenda, I didn't expect that there would be demand to give a presentation on Microsoft PowerShell after all. I already took this topic out of the announcement but the audience wanted to have some information. Okay, then let's see what I could do - improvised style. While my machine booted and got hooked up to the projector, I started to talk about the beginnings of PowerShell from back in 2006, and its predecessors MS DOS and Command Prompt. A throwback in history... always good for young people. As usual, Microsoft didn't get it at that time. Instead of listening to their client's needs and demands they ignored the feasibility to administrate Windows server farms without any UI tools. PowerShell is actually a result of this, and seeing that shell scripting is a common, reliable and fast way in an administrator's toolbox for decades, Microsoft had to adapt from their Microsoft Management Console (MMC) to a broader approach. It's not like shell scripting was something new; it is in daily use by alternative operating systems like AIX, HP UX, Solaris, and last but not least Linux. Most interestingly, Microsoft is very good at renovating existing architectures, and over the years PowerShell not only replaced their own combination of Command Prompt and Scripting Hosts (VBScript and CScript) but really turned into a challenging competitor on the market. The shell is easy to extend with cmdlets, and open to other Microsoft products like SQL Server, SharePoint, as well as Third-party software applications. Similar to MMC PowerShell also offers the ability to administer other machine remotely - only without a graphical user interface and therefore it's easier to automate and schedule regular tasks. Following is a sample of a PowerShell script file (extension .ps1): $strComputer = "." $colItems = get-wmiobject -class Win32_BIOS -namespace root\CIMV2 -comp $strComputer foreach ($objItem in $colItems) {write-host "BIOS Characteristics: " $objItem.BiosCharacteristicswrite-host "BIOS Version: " $objItem.BIOSVersionwrite-host "Build Number: " $objItem.BuildNumberwrite-host "Caption: " $objItem.Captionwrite-host "Code Set: " $objItem.CodeSetwrite-host "Current Language: " $objItem.CurrentLanguagewrite-host "Description: " $objItem.Descriptionwrite-host "Identification Code: " $objItem.IdentificationCodewrite-host "Installable Languages: " $objItem.InstallableLanguageswrite-host "Installation Date: " $objItem.InstallDatewrite-host "Language Edition: " $objItem.LanguageEditionwrite-host "List Of Languages: " $objItem.ListOfLanguageswrite-host "Manufacturer: " $objItem.Manufacturerwrite-host "Name: " $objItem.Namewrite-host "Other Target Operating System: " $objItem.OtherTargetOSwrite-host "Primary BIOS: " $objItem.PrimaryBIOSwrite-host "Release Date: " $objItem.ReleaseDatewrite-host "Serial Number: " $objItem.SerialNumberwrite-host "SMBIOS BIOS Version: " $objItem.SMBIOSBIOSVersionwrite-host "SMBIOS Major Version: " $objItem.SMBIOSMajorVersionwrite-host "SMBIOS Minor Version: " $objItem.SMBIOSMinorVersionwrite-host "SMBIOS Present: " $objItem.SMBIOSPresentwrite-host "Software Element ID: " $objItem.SoftwareElementIDwrite-host "Software Element State: " $objItem.SoftwareElementStatewrite-host "Status: " $objItem.Statuswrite-host "Target Operating System: " $objItem.TargetOperatingSystemwrite-host "Version: " $objItem.Versionwrite-host} Which gives you information about your BIOS and Windows OS. Then change the computer name to another one on your network (NetBIOS based) and run the script again. There lots of samples and tutorials at the Microsoft Script Center, and I would advise you to pay a visit over there if you are more interested in PowerShell. The Script Center provides the download links, too. Upcoming Events What are the upcoming events here in Mauritius? So far, we have the following ones (incomplete list as usual) in chronological order: Hacking Defence (14. May 2014) WebCup Maurice (7. & 8. June 2014) Developers Conference (TBA ~ July 2014) Linuxfest 2014 (TBA ~ November 2014) Hopefully, there will be more announcements during the next couple of weeks and months. If you know about any other event, like a bootcamp, a code challenge or hackathon here in Mauritius, please drop me a note in the comment section below this article. Thanks! My resume of the day Spontaneous and improvised :) The new location at the University of Mauritius turned out very well, there is plenty of space, and it could be a good choice for future meetings. Especially, having the ability to get more and more students into our IT community sounds like a great opportunity. Later during the day, I got some promising mails from Nadim regarding future sessions at the local branch of the Middlesex University. Well, we will see in the future... But for now this will be on hold until approximately October when students resume their regular studies. Anyway, it was a good experience at the university, and thanks again to the UoM Student's Computer Club that made the necessary arrangements for the MSCC!

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  • Mac OS X roaming profile from Samba with OpenLDAP backend on Ubuntu 11.10

    - by Sam Hammamy
    I have been battling for a week now to get my Mac (Mountain Lion) to authenticate on my home network's OpenLDAP and Samba. From several sources, like the Ubuntu community docs, and other blogs, and after a hell of a lot of trial and error and piecing things together, I have created a samba.ldif that will pass the smbldap-populate when combined with apple.ldif and I have a fully functional OpenLDAP server and a Samba PDC that uses LDAP to authenticate the OS X Machine. The problem is that when I login, the home directory is not created or pulled from the server. I get the following in system.log Sep 21 06:09:15 Sams-MacBook-Pro.local SecurityAgent[265]: User info context values set for sam Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in pam_sm_authenticate(): Got user: sam Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in pam_sm_authenticate(): Got ruser: (null) Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in pam_sm_authenticate(): Got service: authorization Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in od_principal_for_user(): no authauth availale for user. Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in od_principal_for_user(): failed: 7 Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in pam_sm_authenticate(): Failed to determine Kerberos principal name. Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in pam_sm_authenticate(): Done cleanup3 Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in pam_sm_authenticate(): Kerberos 5 refuses you Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in pam_sm_authenticate(): pam_sm_authenticate: ntlm Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in pam_sm_acct_mgmt(): OpenDirectory - Membership cache TTL set to 1800. Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in od_record_check_pwpolicy(): retval: 0 Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in pam_sm_setcred(): Establishing credentials Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in pam_sm_setcred(): Got user: sam Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in pam_sm_setcred(): Context initialised Sep 21 06:09:15 Sams-MacBook-Pro.local authorizationhost[270]: in pam_sm_setcred(): pam_sm_setcred: ntlm user sam doesn't have auth authority All that's great and good and I authenticate. Then I get CFPreferences: user home directory for user kCFPreferencesCurrentUser at /Network/Servers/172.17.148.186/home/sam is unavailable. User domains will be volatile. Failed looking up user domain root; url='file://localhost/Network/Servers/172.17.148.186/home/sam/' path=/Network/Servers/172.17.148.186/home/sam/ err=-43 uid=9000 euid=9000 If you're wondering where /Network/Servers/IP/home/sam comes from, it's from a couple of blogs that said the OpenLDAP attribute apple-user-homeDirectory should have that value and the NFSHomeDirectory on the mac should point to apple-user-homeDirectory I also set the attr apple-user-homeurl to <home_dir><url>smb://172.17.148.186/sam/</url><path></path></home_dir> which I found on this forum. Any help is appreciated, because I'm banging my head against the wall at this point. By the way, I intend to create a blog on my vps just for this, and create an install script in python that people can download so no one has to go through what I've had to go through this week :) After some sleep I am going to try to login from a windows machine and report back here. Thanks Sam

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  • Don’t just P2V that server for Testing!

    - by Jonathan Kehayias
    If you use virtualization in your company, at some point in time you might be tempted to perform a Physical-To-Virtual conversion, also known as P2V.  The ability to create a complete working copy of a physical server as a virtual machine is really useful for migrating to a virtualized datacenter, but it can also wreak havoc in your environment if you use it to generate a copy of a server for testing and the only change you make is the name of the server.  The Problem: Consider that you...(read more)

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  • Google I/O 2011: Smart App Design

    Google I/O 2011: Smart App Design Travis Green, Max Lin, Robert Kaplow, Jóhannes Kristinsson, Ryan McGee Learn how to recommend the unexpected, automate the repetitive, and distill the essential using machine learning. This session will show you how you can easily add smarts to your apps with the Prediction API, and how to create apps that rapidly adapt to new data. From: GoogleDevelopers Views: 10078 47 ratings Time: 01:01:04 More in Science & Technology

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  • An Introduction to Cash Till

    Cash till is a machine that can tabulate the amount of sales transactions and usually prints receipt for the customers. It can also make a permanent and cumulative record of the day’s sales. Al... [Author: Alan Wisdom - Computers and Internet - April 05, 2010]

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  • Fix: SqlDeploy Task Fails with NullReferenceException at ExtractPassword

    Still working on getting a TeamCity build working (see my last post).  Latest exception is: C:\Program Files\MSBuild\Microsoft\VisualStudio\v9.0\TeamData\Microsoft.Data.Schema.SqlTasks.targets(120, 5): error MSB4018: The "SqlDeployTask" task failed unexpectedly. System.NullReferenceException: Object reference not set to an instance of an object. at Microsoft.Data.Schema.Common.ConnectionStringPersistence.ExtractPassword(String partialConnection, String dbProvider) at Microsoft.Data.Schema.Common.ConnectionStringPersistence.RetrieveFullConnection(String partialConnection, String provider, Boolean presentUI, String password) at Microsoft.Data.Schema.Sql.Build.SqlDeployment.ConfigureConnectionString(String connectionString, String databaseName) at Microsoft.Data.Schema.Sql.Build.SqlDeployment.OnBuildConnectionString(String partialConnectionString, String databaseName) at Microsoft.Data.Schema.Build.Deployment.FinishInitialize(String targetConnectionString) at Microsoft.Data.Schema.Build.Deployment.Initialize(FileInfo sourceDbSchemaFile, ErrorManager errors, String targetConnectionString) at Microsoft.Data.Schema.Build.DeploymentConstructor.ConstructServiceImplementation() at Microsoft.Data.Schema.Extensibility.ServiceConstructor'1.ConstructService() at Microsoft.Data.Schema.Tasks.DBDeployTask.Execute() at Microsoft.Build.BuildEngine.TaskEngine.ExecuteInstantiatedTask(EngineProxy engineProxy, ItemBucket bucket, TaskExecutionMode howToExecuteTask, ITask task, Boolean& taskResult)   This time searching yielded some good stuff, including this thread that talks about how to resolve this via permissions.  The short answer is that the account that your build server runs under needs to have the necessary permissions in SQL Server.  Youll need to create a Login and then ensure at least the minimum rights are configured as described here: Required Permissions in Database Edition Alternately, you can just make your buildserver account an admin on the database (which is probably running on the same machine anyway) and at that point it should be able to do whatever it needs to. If youre certain the account has the necessary permissions, but youre still getting the error, the problem may be that the account has never logged into the build server.  In this case, there wont be any entry in the HKCU hive in the registry, which the system is checking for permissions (see this thread).  The solution in this case is quite simple: log into the machine (once is enough) with the build server account.  Then, open Visual Studio (thanks Brendan for the answer in this thread). Summary Make sure the build service account has the necessary database permissions Make sure the account has logged into the server so it has the necessary registry hive info Make sure the account has run Visual Studio at least once so its settings are established In my case I went through all 3 of these steps before I resolved the problem. Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Open the SQL Server Error Log with PowerShell

    - by BuckWoody
    Using the Server Management Objects (SMO) library, you don’t even need to have the SQL Server 2008 PowerShell Provider to read the SQL Server Error Logs – in fact, you can use regular old everyday PowerShell. Keep in mind you will need the SMO libraries – which can be installed separately or by installing the Client Tools from the SQL Server install media. You could search for errors, store a result as a variable, or act on the returned values in some other way. Replace the Machine Name with your server and Instance Name with your instance, but leave the quotes, to make this work on your system: [reflection.assembly]::LoadWithPartialName("Microsoft.SqlServer.Smo") $machineName = "UNIVAC" $instanceName = "Production" $sqlServer = new-object ("Microsoft.SqlServer.Management.Smo.Server") "$machineName\$instanceName" $sqlServer.ReadErrorLog() Want to search for something specific, like the word “Error”? Replace the last line with this: $sqlServer.ReadErrorLog() | where {$_.Text -like "Error*"} Script Disclaimer, for people who need to be told this sort of thing: Never trust any script, including those that you find here, until you understand exactly what it does and how it will act on your systems. Always check the script on a test system or Virtual Machine, not a production system. Yes, there are always multiple ways to do things, and this script may not work in every situation, for everything. It’s just a script, people. All scripts on this site are performed by a professional stunt driver on a closed course. Your mileage may vary. Void where prohibited. Offer good for a limited time only. Keep out of reach of small children. Do not operate heavy machinery while using this script. If you experience blurry vision, indigestion or diarrhea during the operation of this script, see a physician immediately. Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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  • Még egy kis Iron Man 2...

    - by Fekete Zoltán
    Az Oracle website-on az Iron Man 2 oldalon található sok információ többek között ezekrol a témákról: - Oracle Cloud Computing - Exadata, Sun Oracle Database Machine - Oracle Enterprise Manager Megnézhetjük az Iron Man 2 trailert is: Iron Man 2 oldalon, továbbá a speciális Oracle szoftver és hardverrol is szóló mozi elozetes megmutatja mit jelent ez a kombináció az innovatív cégeknek.

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  • How to install 3d support?

    - by Gonzalo
    I'm trying Natty and after an upgrade I received this message: "Sorry, you don't have 3d support, install it for your graphic hardware to get Unity or please reboot and select 'Classic session' at startup." So I want to install 3D support but I don't know how to. My machine is a Sony Vaio VGN-SR29XN Laptop with Intel Graphics, but I would like to know the general instructions. P.S. : I've no problem with the CLI, I just don't know how to proceed in this particular case (what driver, or program...).

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  • ASP.NET vNext in Visual Studio &ldquo;14&rdquo; CTP

    - by TATWORTH
    Originally posted on: http://geekswithblogs.net/TATWORTH/archive/2014/06/05/asp.net-vnext-in-visual-studio-ldquo14rdquo-ctp.aspxMicrosoft have issued a long article about Visual Studio “14” CTP at http://blogs.msdn.com/b/webdev/archive/2014/06/03/asp-net-vnext-in-visual-studio-14-ctp.aspx. Please remember that the 14” CTP does NOT have “side-by-side” support and thus should be installed on PC or virtual machine with no other version of Visual Studio installed.

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  • SQL SERVER – Manage Help Settings – CTRL + ALT + F1

    - by pinaldave
    It is a miracle that curiosity survives formal education. ~ Albert Einstein I have 3 years old daughter and she never misses any chance to play with the system. I have multiple computers and I always make sure that if I am working with production server, I never leave it open but when I am doing some experiment I often leave my computer open. My daughter loves the part when I have left the computer open and I am not observing her. Recently I had the same scenario, I got urgent call and I moved away from my computer and when I returned she was playing with SSMS left open my computer. Here is the screen which was visible on the screen. For a moment, I could not figure out what was this screen and what was about to get updated. I tried to ask her what keys she pressed the reaction was “I wanted – eya eya o”. Well, what more I expect from 3 years old. She is no computer genius – she just learned to use notepad and paint on my machine. Finally, when I saw the above screen in detail, I realize that this screen was from the help screen and something got updated. I have been using SQL Server for a long time but I never updated help on the screen. When I need to search something if I remember that I have written it earlier I will go to http://search.sqlauthority.com and will search there or will search on Google. As this computer was already updated I fired up Virtual Machine and tried to look recreate how my daughter was reached to above screen. Here are the steps which I have to do to reach to above screen. Go to SSMS >> Toolbar >> Help >> Manage Help Settings (or type CTRL+ALT+F1) and click it. Above click brought up following screen. I clicked on Check for update online brought following screen up. When I clicked on Update it brought me back to original screen which my daughter was able to bring up earlier. I found it so interesting that what took me 2-3 minutes to figure out and the screen which I have never come across in my career I learned from my curiosity like my daughter. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Database, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • ERP in a Flash! Latest News on JD Edwards and Oracle VM Templates

    - by Kem Butller-Oracle
    Oracle Announces the Availability of Oracle VM Templates for JD Edwards EnterpriseOne 9.1 Update 2 and Tools 9.1 Update 4.4 Continuing the commitment to rapid and predictable deployments of JD Edwards EnterpriseOne, Oracle announces the general availability of Oracle VM templates for JD Edwards EnterpriseOne Application release 9.1 Update 2 and Tools release 9.1 Update 4.4. These templates can be used with Oracle VM for x86, on the Oracle Exalogic Elastic Cloud, and on the Oracle Database Machine. Oracle VM Templates for JD Edwards EnterpriseOne accelerate the process of setting up a working environment compared to the traditional installation process. The templates can be a key component to a well-managed cloud infrastructure, allowing system administrators to quickly provision fully functional JD Edwards EnterpriseOne environments for evaluation, development, or production use. The templates contain preconfigured images of the major JD Edwards EnterpriseOne server components, including: • Enterprise server • HTML server • Database server • BI Publisher (for use with One View Reporting) • Business Services Server and ADF Runtime (for use with Mobile Smartphone Applications) • Application Interface Services (new with this release, for use with Mobile Enterprise Applications) • Server Manager (new with this release) The virtual server images are built on a complete Oracle technology stack, including Oracle VM for x86, Oracle Linux, Oracle WebLogic Server, Oracle Database, and Oracle Business Intelligence Publisher. The templates can be installed into an Oracle VM for x86 system running on standard x86 servers, the Oracle Exalogic Elastic Cloud, and the Oracle Database Appliance as a composite “all-in-one” system. The database can be deployed as a fully preconfigured VM template, or it can be deployed to a preexisting database server, for example, the Oracle Exadata Database Machine or the Oracle Database Appliance. This latest set of templates includes the following applications and technology components: • JD Edwards EnterpriseOne Applications Release 9.1 Update 2 with ESUs as of April 8, 2014 • JD Edwards EnterpriseOne Tools 9.1 Update 4, maintenance pack 4 (9.1.4.4) • Oracle Database 12c (12.1.0.1) • Oracle WebLogic Server 12c (12.1.2) • Oracle Linux 5 Update 8, 64-bit • Oracle Business Intelligence Publisher 11.1.1.7.1, for use with JD Edwards EnterpriseOne One View Reporting • JD Edwards EnterpriseOne Business Services Server and Oracle Application Development Framework (ADF) 11.1.1.5, for use with the JD Edwards EnterpriseOne Mobile Applications. The delivery also includes a JD Edwards EnterpriseOne deployment server preconfigured to match the content of the templates. This edition of the templates also includes enhanced configuration utilities that greatly simplify the process of configuring the templates for deployment into a running system. The templates are immediately available for download from the Oracle Software Delivery Cloud. For more information see: • My Oracle Support article 884592.1 • Oracle Technology Network

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  • Bill Gates: How a Geek Changed the World [Video]

    - by Asian Angel
    Just before he stepped down from Microsoft, BBC2’s “The Money Programme” put together a special on Bill Gates and how he made the company into a money making machine. Those of you who love geek history will definitely enjoy this hour long documentary video. Bill Gates – How A Geek Changed The World [via FavBrowser] What is a Histogram, and How Can I Use it to Improve My Photos?How To Easily Access Your Home Network From Anywhere With DDNSHow To Recover After Your Email Password Is Compromised

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  • ntpd server always in 'INIT' mode

    - by Deepak
    I'm running ntpd server in my ubuntu (10.04) machine. But it is always stays in the 'INIT' state as shown below. lyra@ws07475:~$ ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== europium.canoni .INIT. 16 u - 1024 0 0.000 0.000 0.000 lyra@ws07475:~$ Of course, this means that it is not keeping time. How can I start 'ntpd' server properly ? Please help.

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  • Don’t Miss The Top Exastack ISV Headlines – Week Of June 5

    - by Roxana Babiciu
    Smartsoft's OCEAN Payment Processing Solution achieves Oracle Exadata Optimized status. "Performance is the most important issue for our success in the market and running OCEAN on the Oracle Exadata Database Machine provides customers with extreme performance.” – Learn more Banking solution FORBIS Ltd’s FORPOST achieves Oracle Exadata, Exalogic and SuperCluster Ready Status. “We are glad to offer our current and future customers the newest features provided by Oracle Engineered Systems to achieve maximum reliability and speed operation.” – Learn more

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  • The Google Prediction API

    The Google Prediction API The Prediction API enables you to make your smart apps even smarter. The API accesses Google's machine learning algorithms to analyze your historic data and predict likely future outcomes. Using the Google Prediction API, you can build the following intelligence into your applications. Read more at code.google.com From: GoogleDevelopers Views: 15834 113 ratings Time: 01:37 More in Science & Technology

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  • New Feature in ODI 11.1.1.6: ODI for Big Data

    - by Julien Testut
    Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} By Ananth Tirupattur Starting with Oracle Data Integrator 11.1.1.6.0, ODI is offering a solution to process Big Data. This post provides an overview of this feature. With all the buzz around Big Data and before getting into the details of ODI for Big Data, I will provide a brief introduction to Big Data and Oracle Solution for Big Data. So, what is Big Data? Big data includes: structured data (this includes data from relation data stores, xml data stores), semi-structured data (this includes data from weblogs) unstructured data (this includes data from text blob, images) Traditionally, business decisions are based on the information gathered from transactional data. For example, transactional Data from CRM applications is fed to a decision system for analysis and decision making. Products such as ODI play a key role in enabling decision systems. However, with the emergence of massive amounts of semi-structured and unstructured data it is important for decision system to include them in the analysis to achieve better decision making capability. While there is an abundance of opportunities for business for gaining competitive advantages, process of Big Data has challenges. The challenges of processing Big Data include: Volume of data Velocity of data - The high Rate at which data is generated Variety of data In order to address these challenges and convert them into opportunities, we would need an appropriate framework, platform and the right set of tools. Hadoop is an open source framework which is highly scalable, fault tolerant system, for storage and processing large amounts of data. Hadoop provides 2 key services, distributed and reliable storage called Hadoop Distributed File System or HDFS and a framework for parallel data processing called Map-Reduce. Innovations in Hadoop and its related technology continue to rapidly evolve, hence therefore, it is highly recommended to follow information on the web to keep up with latest information. Oracle's vision is to provide a comprehensive solution to address the challenges faced by Big Data. Oracle is providing the necessary Hardware, software and tools for processing Big Data Oracle solution includes: Big Data Appliance Oracle NoSQL Database Cloudera distribution for Hadoop Oracle R Enterprise- R is a statistical package which is very popular among data scientists. ODI solution for Big Data Oracle Loader for Hadoop for loading data from Hadoop to Oracle. Further details can be found here: http://www.oracle.com/us/products/database/big-data-appliance/overview/index.html ODI Solution for Big Data: ODI’s goal is to minimize the need to understand the complexity of Hadoop framework and simplify the adoption of processing Big Data seamlessly in an enterprise. ODI is providing the capabilities for an integrated architecture for processing Big Data. This includes capability to load data in to Hadoop, process data in Hadoop and load data from Hadoop into Oracle. ODI is expanding its support for Big Data by providing the following out of the box Knowledge Modules (KMs). IKM File to Hive (LOAD DATA).Load unstructured data from File (Local file system or HDFS ) into Hive IKM Hive Control AppendTransform and validate structured data on Hive IKM Hive TransformTransform unstructured data on Hive IKM File/Hive to Oracle (OLH)Load processed data in Hive to Oracle RKM HiveReverse engineer Hive tables to generate models Using the Loading KM you can map files (local and HDFS files) to the corresponding Hive tables. For example, you can map weblog files categorized by date into a corresponding partitioned Hive table schema. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Using the Hive control Append KM you can validate and transform data in Hive. In the below example, two source Hive tables are joined and mapped to a target Hive table. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} The Hive Transform KM facilitates processing of semi-structured data in Hive. In the below example, the data from weblog is processed using a Perl script and mapped to target Hive table. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Using the Oracle Loader for Hadoop (OLH) KM you can load data from Hive table or HDFS to a corresponding table in Oracle. OLH is available as a standalone product. ODI greatly enhances OLH capability by generating the configuration and mapping files for OLH based on the configuration provided in the interface and KM options. ODI seamlessly invokes OLH when executing the scenario. In the below example, a HDFS file is mapped to a table in Oracle. Development and Deployment:The following diagram illustrates the development and deployment of ODI solution for Big Data. Using the ODI Studio on your development machine create and develop ODI solution for processing Big Data by connecting to a MySQL DB or Oracle database on a BDA machine or Hadoop cluster. Schedule the ODI scenarios to be executed on the ODI agent deployed on the BDA machine or Hadoop cluster. ODI Solution for Big Data provides several exciting new capabilities to facilitate the adoption of Big Data in an enterprise. You can find more information about the Oracle Big Data connectors on OTN. You can find an overview of all the new features introduced in ODI 11.1.1.6 in the following document: ODI 11.1.1.6 New Features Overview

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  • C#: LINQ vs foreach - Round 1.

    - by James Michael Hare
    So I was reading Peter Kellner's blog entry on Resharper 5.0 and its LINQ refactoring and thought that was very cool.  But that raised a point I had always been curious about in my head -- which is a better choice: manual foreach loops or LINQ?    The answer is not really clear-cut.  There are two sides to any code cost arguments: performance and maintainability.  The first of these is obvious and quantifiable.  Given any two pieces of code that perform the same function, you can run them side-by-side and see which piece of code performs better.   Unfortunately, this is not always a good measure.  Well written assembly language outperforms well written C++ code, but you lose a lot in maintainability which creates a big techncial debt load that is hard to offset as the application ages.  In contrast, higher level constructs make the code more brief and easier to understand, hence reducing technical cost.   Now, obviously in this case we're not talking two separate languages, we're comparing doing something manually in the language versus using a higher-order set of IEnumerable extensions that are in the System.Linq library.   Well, before we discuss any further, let's look at some sample code and the numbers.  First, let's take a look at the for loop and the LINQ expression.  This is just a simple find comparison:       // find implemented via LINQ     public static bool FindViaLinq(IEnumerable<int> list, int target)     {         return list.Any(item => item == target);     }         // find implemented via standard iteration     public static bool FindViaIteration(IEnumerable<int> list, int target)     {         foreach (var i in list)         {             if (i == target)             {                 return true;             }         }           return false;     }   Okay, looking at this from a maintainability point of view, the Linq expression is definitely more concise (8 lines down to 1) and is very readable in intention.  You don't have to actually analyze the behavior of the loop to determine what it's doing.   So let's take a look at performance metrics from 100,000 iterations of these methods on a List<int> of varying sizes filled with random data.  For this test, we fill a target array with 100,000 random integers and then run the exact same pseudo-random targets through both searches.                       List<T> On 100,000 Iterations     Method      Size     Total (ms)  Per Iteration (ms)  % Slower     Any         10       26          0.00046             30.00%     Iteration   10       20          0.00023             -     Any         100      116         0.00201             18.37%     Iteration   100      98          0.00118             -     Any         1000     1058        0.01853             16.78%     Iteration   1000     906         0.01155             -     Any         10,000   10,383      0.18189             17.41%     Iteration   10,000   8843        0.11362             -     Any         100,000  104,004     1.8297              18.27%     Iteration   100,000  87,941      1.13163             -   The LINQ expression is running about 17% slower for average size collections and worse for smaller collections.  Presumably, this is due to the overhead of the state machine used to track the iterators for the yield returns in the LINQ expressions, which seems about right in a tight loop such as this.   So what about other LINQ expressions?  After all, Any() is one of the more trivial ones.  I decided to try the TakeWhile() algorithm using a Count() to get the position stopped like the sample Pete was using in his blog that Resharper refactored for him into LINQ:       // Linq form     public static int GetTargetPosition1(IEnumerable<int> list, int target)     {         return list.TakeWhile(item => item != target).Count();     }       // traditionally iterative form     public static int GetTargetPosition2(IEnumerable<int> list, int target)     {         int count = 0;           foreach (var i in list)         {             if(i == target)             {                 break;             }               ++count;         }           return count;     }   Once again, the LINQ expression is much shorter, easier to read, and should be easier to maintain over time, reducing the cost of technical debt.  So I ran these through the same test data:                       List<T> On 100,000 Iterations     Method      Size     Total (ms)  Per Iteration (ms)  % Slower     TakeWhile   10       41          0.00041             128%     Iteration   10       18          0.00018             -     TakeWhile   100      171         0.00171             88%     Iteration   100      91          0.00091             -     TakeWhile   1000     1604        0.01604             94%     Iteration   1000     825         0.00825             -     TakeWhile   10,000   15765       0.15765             92%     Iteration   10,000   8204        0.08204             -     TakeWhile   100,000  156950      1.5695              92%     Iteration   100,000  81635       0.81635             -     Wow!  I expected some overhead due to the state machines iterators produce, but 90% slower?  That seems a little heavy to me.  So then I thought, well, what if TakeWhile() is not the right tool for the job?  The problem is TakeWhile returns each item for processing using yield return, whereas our for-loop really doesn't care about the item beyond using it as a stop condition to evaluate. So what if that back and forth with the iterator state machine is the problem?  Well, we can quickly create an (albeit ugly) lambda that uses the Any() along with a count in a closure (if a LINQ guru knows a better way PLEASE let me know!), after all , this is more consistent with what we're trying to do, we're trying to find the first occurence of an item and halt once we find it, we just happen to be counting on the way.  This mostly matches Any().       // a new method that uses linq but evaluates the count in a closure.     public static int TakeWhileViaLinq2(IEnumerable<int> list, int target)     {         int count = 0;         list.Any(item =>             {                 if(item == target)                 {                     return true;                 }                   ++count;                 return false;             });         return count;     }     Now how does this one compare?                         List<T> On 100,000 Iterations     Method         Size     Total (ms)  Per Iteration (ms)  % Slower     TakeWhile      10       41          0.00041             128%     Any w/Closure  10       23          0.00023             28%     Iteration      10       18          0.00018             -     TakeWhile      100      171         0.00171             88%     Any w/Closure  100      116         0.00116             27%     Iteration      100      91          0.00091             -     TakeWhile      1000     1604        0.01604             94%     Any w/Closure  1000     1101        0.01101             33%     Iteration      1000     825         0.00825             -     TakeWhile      10,000   15765       0.15765             92%     Any w/Closure  10,000   10802       0.10802             32%     Iteration      10,000   8204        0.08204             -     TakeWhile      100,000  156950      1.5695              92%     Any w/Closure  100,000  108378      1.08378             33%     Iteration      100,000  81635       0.81635             -     Much better!  It seems that the overhead of TakeAny() returning each item and updating the state in the state machine is drastically reduced by using Any() since Any() iterates forward until it finds the value we're looking for -- for the task we're attempting to do.   So the lesson there is, make sure when you use a LINQ expression you're choosing the best expression for the job, because if you're doing more work than you really need, you'll have a slower algorithm.  But this is true of any choice of algorithm or collection in general.     Even with the Any() with the count in the closure it is still about 30% slower, but let's consider that angle carefully.  For a list of 100,000 items, it was the difference between 1.01 ms and 0.82 ms roughly in a List<T>.  That's really not that bad at all in the grand scheme of things.  Even running at 90% slower with TakeWhile(), for the vast majority of my projects, an extra millisecond to save potential errors in the long term and improve maintainability is a small price to pay.  And if your typical list is 1000 items or less we're talking only microseconds worth of difference.   It's like they say: 90% of your performance bottlenecks are in 2% of your code, so over-optimizing almost never pays off.  So personally, I'll take the LINQ expression wherever I can because they will be easier to read and maintain (thus reducing technical debt) and I can rely on Microsoft's development to have coded and unit tested those algorithm fully for me instead of relying on a developer to code the loop logic correctly.   If something's 90% slower, yes, it's worth keeping in mind, but it's really not until you start get magnitudes-of-order slower (10x, 100x, 1000x) that alarm bells should really go off.  And if I ever do need that last millisecond of performance?  Well then I'll optimize JUST THAT problem spot.  To me it's worth it for the readability, speed-to-market, and maintainability.

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  • C#: Does an IDisposable in a Halted Iterator Dispose?

    - by James Michael Hare
    If that sounds confusing, let me give you an example. Let's say you expose a method to read a database of products, and instead of returning a List<Product> you return an IEnumerable<Product> in iterator form (yield return). This accomplishes several good things: The IDataReader is not passed out of the Data Access Layer which prevents abstraction leak and resource leak potentials. You don't need to construct a full List<Product> in memory (which could be very big) if you just want to forward iterate once. If you only want to consume up to a certain point in the list, you won't incur the database cost of looking up the other items. This could give us an example like: 1: // a sample data access object class to do standard CRUD operations. 2: public class ProductDao 3: { 4: private DbProviderFactory _factory = SqlClientFactory.Instance 5:  6: // a method that would retrieve all available products 7: public IEnumerable<Product> GetAvailableProducts() 8: { 9: // must create the connection 10: using (var con = _factory.CreateConnection()) 11: { 12: con.ConnectionString = _productsConnectionString; 13: con.Open(); 14:  15: // create the command 16: using (var cmd = _factory.CreateCommand()) 17: { 18: cmd.Connection = con; 19: cmd.CommandText = _getAllProductsStoredProc; 20: cmd.CommandType = CommandType.StoredProcedure; 21:  22: // get a reader and pass back all results 23: using (var reader = cmd.ExecuteReader()) 24: { 25: while(reader.Read()) 26: { 27: yield return new Product 28: { 29: Name = reader["product_name"].ToString(), 30: ... 31: }; 32: } 33: } 34: } 35: } 36: } 37: } The database details themselves are irrelevant. I will say, though, that I'm a big fan of using the System.Data.Common classes instead of your provider specific counterparts directly (SqlCommand, OracleCommand, etc). This lets you mock your data sources easily in unit testing and also allows you to swap out your provider in one line of code. In fact, one of the shared components I'm most proud of implementing was our group's DatabaseUtility library that simplifies all the database access above into one line of code in a thread-safe and provider-neutral way. I went with my own flavor instead of the EL due to the fact I didn't want to force internal company consumers to use the EL if they didn't want to, and it made it easy to allow them to mock their database for unit testing by providing a MockCommand, MockConnection, etc that followed the System.Data.Common model. One of these days I'll blog on that if anyone's interested. Regardless, you often have situations like the above where you are consuming and iterating through a resource that must be closed once you are finished iterating. For the reasons stated above, I didn't want to return IDataReader (that would force them to remember to Dispose it), and I didn't want to return List<Product> (that would force them to hold all products in memory) -- but the first time I wrote this, I was worried. What if you never consume the last item and exit the loop? Are the reader, command, and connection all disposed correctly? Of course, I was 99.999999% sure the creators of C# had already thought of this and taken care of it, but inspection in Reflector was difficult due to the nature of the state machines yield return generates, so I decided to try a quick example program to verify whether or not Dispose() will be called when an iterator is broken from outside the iterator itself -- i.e. before the iterator reports there are no more items. So I wrote a quick Sequencer class with a Dispose() method and an iterator for it. Yes, it is COMPLETELY contrived: 1: // A disposable sequence of int -- yes this is completely contrived... 2: internal class Sequencer : IDisposable 3: { 4: private int _i = 0; 5: private readonly object _mutex = new object(); 6:  7: // Constructs an int sequence. 8: public Sequencer(int start) 9: { 10: _i = start; 11: } 12:  13: // Gets the next integer 14: public int GetNext() 15: { 16: lock (_mutex) 17: { 18: return _i++; 19: } 20: } 21:  22: // Dispose the sequence of integers. 23: public void Dispose() 24: { 25: // force output immediately (flush the buffer) 26: Console.WriteLine("Disposed with last sequence number of {0}!", _i); 27: Console.Out.Flush(); 28: } 29: } And then I created a generator (infinite-loop iterator) that did the using block for auto-Disposal: 1: // simply defines an extension method off of an int to start a sequence 2: public static class SequencerExtensions 3: { 4: // generates an infinite sequence starting at the specified number 5: public static IEnumerable<int> GetSequence(this int starter) 6: { 7: // note the using here, will call Dispose() when block terminated. 8: using (var seq = new Sequencer(starter)) 9: { 10: // infinite loop on this generator, means must be bounded by caller! 11: while(true) 12: { 13: yield return seq.GetNext(); 14: } 15: } 16: } 17: } This is really the same conundrum as the database problem originally posed. Here we are using iteration (yield return) over a large collection (infinite sequence of integers). If we cut the sequence short by breaking iteration, will that using block exit and hence, Dispose be called? Well, let's see: 1: // The test program class 2: public class IteratorTest 3: { 4: // The main test method. 5: public static void Main() 6: { 7: Console.WriteLine("Going to consume 10 of infinite items"); 8: Console.Out.Flush(); 9:  10: foreach(var i in 0.GetSequence()) 11: { 12: // could use TakeWhile, but wanted to output right at break... 13: if(i >= 10) 14: { 15: Console.WriteLine("Breaking now!"); 16: Console.Out.Flush(); 17: break; 18: } 19:  20: Console.WriteLine(i); 21: Console.Out.Flush(); 22: } 23:  24: Console.WriteLine("Done with loop."); 25: Console.Out.Flush(); 26: } 27: } So, what do we see? Do we see the "Disposed" message from our dispose, or did the Dispose get skipped because from an "eyeball" perspective we should be locked in that infinite generator loop? Here's the results: 1: Going to consume 10 of infinite items 2: 0 3: 1 4: 2 5: 3 6: 4 7: 5 8: 6 9: 7 10: 8 11: 9 12: Breaking now! 13: Disposed with last sequence number of 11! 14: Done with loop. Yes indeed, when we break the loop, the state machine that C# generates for yield iterate exits the iteration through the using blocks and auto-disposes the IDisposable correctly. I must admit, though, the first time I wrote one, I began to wonder and that led to this test. If you've never seen iterators before (I wrote a previous entry here) the infinite loop may throw you, but you have to keep in mind it is not a linear piece of code, that every time you hit a "yield return" it cedes control back to the state machine generated for the iterator. And this state machine, I'm happy to say, is smart enough to clean up the using blocks correctly. I suspected those wily guys and gals at Microsoft engineered it well, and I wasn't disappointed. But, I've been bitten by assumptions before, so it's good to test and see. Yes, maybe you knew it would or figured it would, but isn't it nice to know? And as those campy 80s G.I. Joe cartoon public service reminders always taught us, "Knowing is half the battle...". Technorati Tags: C#,.NET

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