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• Pure virtual or abstract, what's in a name?

  - by Steven Jeuris

  While discussing a question about virtual functions on Stack Overflow, I wondered whether there was any official naming for pure (abstract) and non-pure virtual functions. I always relied on wikipedia for my information, which states that pure and non-pure virtual functions are the general term. Unfortunately, the article doesn't back it up with a origin or references. To quote Jon Skeet's answer to my reply that pure and non-pure are the general term used: @Steven: Hmm... possibly, but I've only ever seen it in the context of C++ before. I suspect anyone talking about them is likely to have a C++ background :) Did the terms originate from C++, or were they first defined or implemented in a earlier language, and are they the 'official' scientific terms?

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• Use virtual pageviews for all goal tracking

  - by Jeff Wu

  I'm new to Google Analytics and I'm wondering if it would be cleaner to user virtual pageviews for all the goal tracking on my website instead of using a mix of regular page views and virtual pageviews. I know in most cases this is just semantics but there are multiple pages where the same goal can be achieved and I think it would be cleaner just to fire the same virtual pageview instead of having two different goal pages. Will this model also give developers more flexibility when they do development? I know we are moving to a CMS and urls can get hairy, so I think this might be a good way to make analytics portion of the site "future proof". Any thoughts are appreciated! Thanks.

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• Use virtual pageviews for all goal tracking

  - by Jeff Wu

  Hi Pro Webmasters, I'm new to Google Analytics and I'm wondering if it would be cleaner to user virtual pageviews for all the goal tracking on my website instead of using a mix of regular page views and virtual pageviews. I know in most cases this is just semantics but there are multiple pages where the same goal can be achieved and I think it would be cleaner just to fire the same virtual pageview instead of having two different goal pages. Will this model also give developers more flexibility when they do development? I know we are moving to a CMS and urls can get hairy, so I think this might be a good way to make analytics portion of the site "future proof". Any thoughts are appreciated! Thanks.

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• Virtual Developer Day: Oracle Fusion Development (July 10, Americas TZ)

  - by oracletechnet

  Help! We love bringing Virtual Developer Days to you, and we can't stop! Yes,  again we're proud and happy to offer you the newest flavor of Virtual Developer Day, this one to debut on July 10 in the Americas timezones: Oracle Fusion Development (register). In this workshop, we'll give you a deep dive into the ever-expanding world of Oracle ADF, including: Oracle ADF vs. Oracle APEX use cases Oracle ADF Mobile Development Oracle ADF + Eclipse Oracle WebCenter and Oracle ADF Development and more.... Looks like paradise for Oracle ADF junkies, or developers who aspire to become one. As is the case with all our Virtual Developer Days, Oracle PMs will be on call via live chat to answer your questions and provide support. Get on board!

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• Ubuntu on a virtual machine

  - by Barry Miller

  I've installed Virtual Box and am trying to install Ubuntu 12.04 from a downloaded ISO. Everything is going fine but I come to a choice that says no operating system is dectected on this machine, what would you like to do? 1)Erase disk and install Ubuntu (this will erase any files on the disk) or 2) Something else (choose partition size, multiple partitions, etc). Does the first option mean erase all files on the VIRTUAL DISK--NOT THE COMPUTER? Is it just talking about the virtual machine or if I select this option will it erase my Windows operating system and other files on my hard drive?

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• Virtual screen size with libgdx and GLES 2

  - by David Saltares Márquez

  I've been trying to use a virtual screen size for my libgdx desktop-android game. I'd like to always use a 16:9 aspect ratio but with a virtual screen size so everything would adapt automatically depending on the device size. This post illustrates the process pretty well but my game crashes when camera.apply(Gdx.Gl10) is called. This is because I'm using GLES 2.0 (for not having to use multiple of 2 texture sizes). As stated in the OrthographicCamera doc, the apply method only works with GLES 1 and GLES 1.1. Is there another way of applying my GL transformation to the camera so I can use a virtual screen resolution? Having to resize everything manually it's a total pain. Thanks a lot.

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• Hyper-V Virtual Ethernet Adapter not working probperly - Code 31 on Host

  - by Chris S

  I have a Windows 8.1 machine with Hyper-V installed. From a "clean" Hyper-V configuration I open Virtual Switch Manager, create an External switch with "Allow management operating system to share this network adapter", click OK. Everything seems to work properly but the host loses network connectivity. Opening Device Manager, the "Hyper-V Virtual Ethernet Adapter" is shown under the Network Adapter section with a yellow triangle, and the following message: This device is not working properly because Windows cannot load the drivers required for this device. (Code 31) An object ID was not found in the file. I tried "Uninstalling" the device, seems to work, but the device doesn't actually remove. I tried removing and re-adding the Hyper-V feature completely, no difference. Tried scf /scannow, no problems. System and Application logs show no errors. The Hyper-V-VMMS Networking log shows the following: Log Name: Microsoft-Windows-Hyper-V-VMMS-Networking Source: Microsoft-Windows-Hyper-V-VMMS Date: 10/24/2013 10:53:07 AM Event ID: 26088 Description: Failed to apply static IP settings to internal Ethernet adapter {A813DE9A-BE70-4FAE-AD31-BE4D54505A4B} ('885435B8-BE65-4EE9-826D-AB56035237ED'): Unspecified error (0x80004005). If I try to remove the Virtual Switch in Hyper-V Virtual Switch Manager I get this in that same log: Log Name: Microsoft-Windows-Hyper-V-VMMS-Networking Source: Microsoft-Windows-Hyper-V-VMMS Date: 10/24/2013 11:19:47 AM Event ID: 26142 Description: Failed while removing virtual Ethernet switch. Trying to remove the Virtual Switch leads to an error: Error applying Virtual Switch Properties changes Failed while removing virtual Ethernet switch. VM Networking does work.

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• Troubles with apache and virtual hosts

  - by xZero

  I have a BIG problem. I have VPS with Debian OS, and LAMP installed. Fresh install. For control panel i using Webmin. Now i trying to setup multiple sub-domains on my server using webmin for example: downloads.my-domain.com cpanel.my-domains.com forum.my-domains.com But problem what is happening is next, while i using no virtual hosts, everything works perfectly when i accessing it using my-domain.com, but when i add Virtual host, i cann access it but my-domain.com becomes unavilable because it redirects to virtual hosts i added. When i add more than 2 virtual hosts, problem is still here. Also, when i try to access to virtual server for example downloads.my-domain.com, it redirects again to cpanel.my-domains.com When i delete virtual hosts, access to my-domain.com is succesfull... What i known: - That is not problem with my domain provider. I correctly added subdomains and added host record to my VPS IP. - I added unique name to every single virtual host. - There are no two same virtual hosts - Every virtaul hosts have own directory: for example: downloads.my-domain.com have own WWW dir: /var/downloads Can somebody help me? Thanks.

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• Clone current host OS to a guest virtual machine.

  - by ProfKaos

  I would like to run a few repeated checks on a setup procedure I am documenting, to verify my document. I would like to somehow create a VM that replicates the environment on my machine, i.e. the host machine, onto a guest VM. Then I can use Windows' System Restore on the guest to start at the point before I commenced the setup procedure and repeat it as many times as required until no more trial-and-error etc. is required to supplement my document. I have Virtual PC and VirtualBox available to install as host environments, running on Windows 7 Professional.

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• Setting up and using Bing Translate API Service for Machine Translation

  - by Rick Strahl

  Last week I spent quite a bit of time trying to set up the Bing Translate API service. I can honestly say this was one of the most screwed up developer experiences I've had in a long while - specifically related to the byzantine sign up process that Microsoft has in place. Not only is it nearly impossible to find decent documentation on the required signup process, some of the links in the docs are just plain wrong, and some of the account pages you need to access the actual account information once signed up are not linked anywhere from the administration UI. To make things even harder is the fact that the APIs changed a while back, with a completely new authentication scheme that's described and not directly linked documentation topic also made for a very frustrating search experience. It's a bummer that this is the case too, because the actual API itself is easy to use and works very well - fast and reasonably accurate (as accurate as you can expect machine translation to be). But the sign up process is a pain in the ass doubtlessly leaving many people giving up in frustration. In this post I'll try to hit all the points needed to set up to use the Bing Translate API in one place since such a document seems to be missing from Microsoft. Hopefully the API folks at Microsoft will get their shit together and actually provide this sort of info on their site… Signing Up The first step required is to create a Windows Azure MarketPlace account. Go to: https://datamarket.azure.com/ Sign in with your Windows Live Id If you don't have an account you will be taken to a registration page which you have to fill out. Follow the links and complete the registration. Once you're signed in you can start adding services. Click on the Data Link on the main page Select Microsoft Translator from the list This adds the Microsoft Bing Translator to your services. Pricing The page shows the pricing matrix and the free service which provides 2 megabytes for translations a month for free. Prices go up steeply from there. Pricing is determined by actual bytes of the result translations used. Max translations are 1000 characters so at minimum this means you get around 2000 translations a month for free. However most translations are probable much less so you can expect larger number of translations to go through. For testing or low volume translations this should be just fine. Once signed up there are no further instructions and you're left in limbo on the MS site. Register your Application Once you've created the Data association with Translator the next step is registering your application. To do this you need to access your developer account. Go to https://datamarket.azure.com/developer/applications/register Provide a ClientId, which is effectively the unique string identifier for your application (not your customer id!) Provide your name The client secret was auto-created and this becomes your 'password' For the redirect url provide any https url: https://microsoft.com works Give this application a description of your choice so you can identify it in the list of apps Now, once you've registered your application, keep track of the ClientId and ClientSecret - those are the two keys you need to authenticate before you can call the Translate API. Oddly the applications page is hidden from the Azure Portal UI. I couldn't find a direct link from anywhere on the site back to this page where I can examine my developer application keys. To find them you can go to: https://datamarket.azure.com/developer/applications You can come back here to look at your registered applications and pick up the ClientID and ClientSecret. Fun eh? But we're now ready to actually call the API and do some translating. Using the Bing Translate API The good news is that after this signup hell, using the API is pretty straightforward. To use the translation API you'll need to actually use two services: You need to call an authentication API service first, before you can call the actual translator API. These two APIs live on different domains, and the authentication API returns JSON data while the translator service returns XML. So much for consistency. Authentication The first step is authentication. The service uses oAuth authentication with a  bearer token that has to be passed to the translator API. The authentication call retrieves the oAuth token that you can then use with the translate API call. The bearer token has a short 10 minute life time, so while you can cache it for successive calls, the token can't be cached for long periods. This means for Web backend requests you typically will have to authenticate each time unless you build a more elaborate caching scheme that takes the timeout into account (perhaps using the ASP.NET Cache object). For low volume operations you can probably get away with simply calling the auth API for every translation you do. To call the Authentication API use code like this:/// /// Retrieves an oAuth authentication token to be used on the translate /// API request. The result string needs to be passed as a bearer token /// to the translate API. /// /// You can find client ID and Secret (or register a new one) at: /// https://datamarket.azure.com/developer/applications/ /// /// The client ID of your application /// The client secret or password /// public string GetBingAuthToken(string clientId = null, string clientSecret = null) { string authBaseUrl = https://datamarket.accesscontrol.windows.net/v2/OAuth2-13; if (string.IsNullOrEmpty(clientId) || string.IsNullOrEmpty(clientSecret)) { ErrorMessage = Resources.Resources.Client_Id_and_Client_Secret_must_be_provided; return null; } var postData = string.Format("grant_type=client_credentials&client_id={0}" + "&client_secret={1}" + "&scope=http://api.microsofttranslator.com", HttpUtility.UrlEncode(clientId), HttpUtility.UrlEncode(clientSecret)); // POST Auth data to the oauth API string res, token; try { var web = new WebClient(); web.Encoding = Encoding.UTF8; res = web.UploadString(authBaseUrl, postData); } catch (Exception ex) { ErrorMessage = ex.GetBaseException().Message; return null; } var ser = new JavaScriptSerializer(); var auth = ser.Deserialize<BingAuth>(res); if (auth == null) return null; token = auth.access_token; return token; } private class BingAuth { public string token_type { get; set; } public string access_token { get; set; } } This code basically takes the client id and secret and posts it at the oAuth endpoint which returns a JSON string. Here I use the JavaScript serializer to deserialize the JSON into a custom object I created just for deserialization. You can also use JSON.NET and dynamic deserialization if you are already using JSON.NET in your app in which case you don't need the extra type. In my library that houses this component I don't, so I just rely on the built in serializer. The auth method returns a long base64 encoded string which can be used as a bearer token in the translate API call. Translation Once you have the authentication token you can use it to pass to the translate API. The auth token is passed as an Authorization header and the value is prefixed with a 'Bearer ' prefix for the string. Here's what the simple Translate API call looks like:/// /// Uses the Bing API service to perform translation /// Bing can translate up to 1000 characters. /// /// Requires that you provide a CLientId and ClientSecret /// or set the configuration values for these two. /// /// More info on setup: /// http://www.west-wind.com/weblog/ /// /// Text to translate /// Two letter culture name /// Two letter culture name /// Pass an access token retrieved with GetBingAuthToken. /// If not passed the default keys from .config file are used if any /// public string TranslateBing(string text, string fromCulture, string toCulture, string accessToken = null) { string serviceUrl = "http://api.microsofttranslator.com/V2/Http.svc/Translate"; if (accessToken == null) { accessToken = GetBingAuthToken(); if (accessToken == null) return null; } string res; try { var web = new WebClient(); web.Headers.Add("Authorization", "Bearer " + accessToken); string ct = "text/plain"; string postData = string.Format("?text={0}&from={1}&to={2}&contentType={3}", HttpUtility.UrlEncode(text), fromCulture, toCulture, HttpUtility.UrlEncode(ct)); web.Encoding = Encoding.UTF8; res = web.DownloadString(serviceUrl + postData); } catch (Exception e) { ErrorMessage = e.GetBaseException().Message; return null; } // result is a single XML Element fragment var doc = new XmlDocument(); doc.LoadXml(res); return doc.DocumentElement.InnerText; } The first of this code deals with ensuring the auth token exists. You can either pass the token into the method manually or let the method automatically retrieve the auth code on its own. In my case I'm using this inside of a Web application and in that situation I simply need to re-authenticate every time as there's no convenient way to manage the lifetime of the auth cookie. The auth token is added as an Authorization HTTP header prefixed with 'Bearer ' and attached to the request. The text to translate, the from and to language codes and a result format are passed on the query string of this HTTP GET request against the Translate API. The translate API returns an XML string which contains a single element with the translated string. Using the Wrapper Methods It should be pretty obvious how to use these two methods but here are a couple of test methods that demonstrate the two usage scenarios:[TestMethod] public void TranslateBingWithAuthTest() { var translate = new TranslationServices(); string clientId = DbResourceConfiguration.Current.BingClientId; string clientSecret = DbResourceConfiguration.Current.BingClientSecret; string auth = translate.GetBingAuthToken(clientId, clientSecret); Assert.IsNotNull(auth); string text = translate.TranslateBing("Hello World we're back home!", "en", "de",auth); Assert.IsNotNull(text, translate.ErrorMessage); Console.WriteLine(text); } [TestMethod] public void TranslateBingIntegratedTest() { var translate = new TranslationServices(); string text = translate.TranslateBing("Hello World we're back home!","en","de"); Assert.IsNotNull(text, translate.ErrorMessage); Console.WriteLine(text); } Other API Methods The Translate API has a number of methods available and this one is the simplest one but probably also the most common one that translates a single string. You can find additional methods for this API here: http://msdn.microsoft.com/en-us/library/ff512419.aspx Soap and AJAX APIs are also available and documented on MSDN: http://msdn.microsoft.com/en-us/library/dd576287.aspx These links will be your starting points for calling other methods in this API. Dual Interface I've talked about my database driven localization provider here in the past, and it's for this tool that I added the Bing localization support. Basically I have a localization administration form that allows me to translate individual strings right out of the UI, using both Google and Bing APIs: As you can see in this example, the results from Google and Bing can vary quite a bit - in this case Google is stumped while Bing actually generated a valid translation. At other times it's the other way around - it's pretty useful to see multiple translations at the same time. Here I can choose from one of the values and driectly embed them into the translated text field. Lost in Translation There you have it. As I mentioned using the API once you have all the bureaucratic crap out of the way calling the APIs is fairly straight forward and reasonably fast, even if you have to call the Auth API for every call. Hopefully this post will help out a few of you trying to navigate the Microsoft bureaucracy, at least until next time Microsoft upends everything and introduces new ways to sign up again. Until then - happy translating… Related Posts Translation method Source on Github Translating with Google Translate without Google API Keys Creating a data-driven ASP.NET Resource Provider© Rick Strahl, West Wind Technologies, 2005-2013Posted in Localization  ASP.NET  .NET   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Virtual Lan on the Cloud -- Help Confirm my understanding?

  - by marfarma

  [Note: Tried to post this over at ServerFault, but I don't have enough 'points' for more than one link. Powers that be, move this question over there.] Please give this a quick read and let me know if I'm missing something before I start trying to make this work. I'm not a systems admin professional, and I'd hate to end up banging my head into the wall if I can avoid it. Goals: Create a 'road-warrior' capable star shaped virtual LAN for consultants who spend the majority of their time on client sites, and who's firm has no physical network or servers. Enable CIFS access to a cloud-server based installation of Alfresco Allow Eventual implementation of some form of single-sign-on ( OpenLDAP server ) access to Alfresco and other server applications implemented in the future Given: All Servers will live in the public internet cloud (Rackspace Cloud Servers) OpenVPN Server will be a Linux disto, probably Ubuntu 9.x, installed on same server as Alfresco (at least to start) Staff will access server applications and resources from client sites, hotels, trains, planes, coffee shops or their homes over various ISP, using their company laptops or personal home desktops. Based on my Research thus far, to accomplish this, I'll need: OpenVPN with Bridging Enabled to create a star shaped "virtual" LAN http://openvpn.net/index.php/open-source/documentation/miscellaneous/76-ethernet-bridging.html A Road Warrior Network Configuration, as described in this Shorewall article (lower down the page) http://www.shorewall.net/OPENVPN.html Configure bridge addressesing (probably DHCP) http://openvpn.net/index.php/open-source/faq.html#bridge-addressing Configure CIFS / Samba to accept VPN IP address http://serverfault.com/questions/137933/howto-access-samba-share-over-vpn-tunnel Set up Client software, with keys configured for access (potentially through a OpenVPN-Sa client portal) http://www.openvpn.net/index.php/access-server/download-openvpn-as/221-installation-overview.html

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• C++ vs. C++/CLI: Const qualification of virtual function parameters

  - by James McNellis

  [All of the following was tested using Visual Studio 2008 SP1] In C++, const qualification of parameter types does not affect the type of a function (8.3.5/3: "Any cv-qualifier modifying a parameter type is deleted") So, for example, in the following class hierarchy, Derived::Foo overrides Base::Foo: struct Base { virtual void Foo(const int i) { } }; struct Derived : Base { virtual void Foo(int i) { } }; Consider a similar hierarchy in C++/CLI: ref class Base abstract { public: virtual void Foo(const int) = 0; }; ref class Derived : public Base { public: virtual void Foo(int i) override { } }; If I then create an instance of Derived: int main(array<System::String ^> ^args) { Derived^ d = gcnew Derived; } it compiles without errors or warnings. When I run it, it throws the following exception and then terminates: An unhandled exception of type 'System.TypeLoadException' occurred in ClrVirtualTest.exe Additional information: Method 'Foo' in type 'Derived'...does not have an implementation. That exception seems to indicate that the const qualification of the parameter does affect the type of the function in C++/CLI (or, at least it affects overriding in some way). However, if I comment out the line containing the definition of Derived::Foo, the compiler reports the following error (on the line in main where the instance of Derived is instantiated): error C2259: 'Derived': cannot instantiate abstract class If I add the const qualifier to the parameter of Derived::Foo or remove the const qualifier from the parameter of Base::Foo, it compiles and runs with no errors. I would think that if the const qualification of the parameter affects the type of the function, I should get this error if the const qualification of the parameter in the derived class virtual function does not match the const qualification of the parameter in the base class virtual function. If I change the type of Derived::Foo's parameter from an int to a double, I get the following warning (in addition to the aforementioned error, C2259): warning C4490: 'override': incorrect use of override specifier; 'Derived::Foo' does not match a base ref class method So, my question is, effectively, does the const qualification of function parameters affect the type of the function in C++/CLI? If so, why does this compile and why are there no errors or warnings? If not, why is an exception thrown?

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• Should we create Virtual Machine environment so a consultant can develop in similiar environment?

  - by ChrisNel52

  This is a large project and currently there are only 3 developers working on it. We have some money in the budget to contract development help from a software consulting firm. However, because the location of our business it would be beneficial if the consultant could do their development off-site. Also, our company policy doesn't allow contract help to VPN into our network, so that is not an option. My question is, would it be a good idea to create a Virtual Machine that copies our internal environment (particularly our database and WCF service) and give the consultant the Virtual Machine image so that they can replicate the environment at their place of work? I haven't worked much with Virtual Machines, so I'm not sure if this is a good idea or if there are huge obstacles that I'm not thinking of. If anyone has ever done anything like this, it would be great to hear the pros/cons. Any help would be appreciated.

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• Windows based development environment: HyperV, VMWare, or VirtualBox on development machine?

  - by bleepzter

  I am a software engineer with a little bit of an informal "support" functionality... I am trying to figure out what is the best possible approach to employing virtualization technologies into our development process. Since the code we develop is server-centric, testing it often requires a VM with specific software requirements. I used to use VM Ware player (free version) to run my VM's until both of my laptops started exhibiting issues with corrupted windows 7 services and dying hard drives. All leads pointed to VMWare, which by the way seems to be a solid product if you pay for the Workstation edition ($300). On a side note, I have always been a fan of the Windows Server product line. I think it makes for one of the best development environments out there - it is highly scalable, highly reliable, and very efficient. So to be fair I replaced the drives of the laptops and installed Windows Server 2008R2, VS2010 Ultimate SP1, SQL Server 2008R2, TFS Server 2010 and all other tools and API's needed do do my work properly. So now I am stuck with a bunch of VMWare VMs. I don't want to repeat of what happened before, and I certainly don't want to bog down my machine with an inefficient hypervisor or services that are not needed. Futhermore the VMDK hard-disk format used by VMWare is not compatible with the VHD format of Hyper V. It is my understanding that converting from one format to the other can only happen by Microsoft System Center Virtual Machine which I have downloaded from MSDN and ready to install. I guess the question at this point is: Does SCVM run as another service in Windows? Is it a memory hog? What is a better virtualization technology - Hyper-V or Virtual Box in terms of efficiency ease of use and most importantly - memory footprint? (Keep in mind the development environment already has a ton of services running such as TFS Server, SQL Server, IIS, etc...) How would you advise to proceed at this point so that the VMs are still used in the test process? Thanks Martin

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• Debug website on host from virtual machine

  - by Luchaguate

  I have a Windows 7 machine hosting a Windows 7 virtual machine. I am developing a web application using visual studio 2010 on my host machine. I want to run the application in debug mode and access my localhost server from a browser on the virtual machine. (The purpose of this is to be able to debug an application that uses Windows Authentication using different users without having to log off and on for different users on my host machine...) I am using a bridged connection for the virtual machine. I googled how to solve this problem and most of the threads that I found said that if I was using a bridged connection, I could access the server on the host machine by just entering the IP address of my host machine into the url in the browser of the virtual machine. I have tried some different urls using the IP but none of them have worked. As an example, suppose I run my web application in visual studio on my host machine and its url is http://localhost:62789/MyPage.aspx Assume also that I ran ipconfig in CommandPrompt on my host machine and found out that the IP address for my host machine is xxx.xxx.xxx.x. What url should I enter on the virtual machine to access my web application? Thanks in advance.

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• Why doesn't g++ pay attention to __attribute__((pure)) for virtual functions?

  - by jchl

  According to the GCC documentation, __attribute__((pure)) tells the compiler that a function has no side-effects, and so it can be subject to common subexpression elimination. This attribute appears to work for non-virtual functions, but not for virtual functions. For example, consider the following code: extern void f( int ); class C { public: int a1(); int a2() __attribute__((pure)); virtual int b1(); virtual int b2() __attribute__((pure)); }; void test_a1( C *c ) { if( c->a1() ) { f( c->a1() ); } } void test_a2( C *c ) { if( c->a2() ) { f( c->a2() ); } } void test_b1( C *c ) { if( c->b1() ) { f( c->b1() ); } } void test_b2( C *c ) { if( c->b2() ) { f( c->b2() ); } } When compiled with optimization enabled (either -O2 or -Os), test_a2() only calls C::a2() once, but test_b2() calls b2() twice. Is there a reason for this? Is it because, even though the implementation in class C is pure, g++ can't assume that the implementation in every subclass will also be pure? If so, is there a way to tell g++ that this virtual function and every subclass's implementation will be pure?

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• New Exadata Book Available Soon

  - by Rob Reynolds

  Oracle Press is set to released the first book on data warehouse performance and Exadata on March 14th. Achieving Extreme Performance with Oracle Exadata , by my colleagues Rick Greenwald, Robert Stackowiak, Maqsood Alam, and Mans Bhuller will be available at your favorite booksellers next week. I've seen a sneak peak of the content in this book and its a great way to fully grasp the power of Exadata and how to best apply it to achieve extreme data warehouse performance. From the publisher's description: Achieving Extreme Performance with Oracle Exadata and the Sun Oracle Database Machine is filled with best practices for deployments, hardware sizing, architecting the database machine environments for maximum availability, and backup and recovery. Oracle Database 11gR2 features used within these offerings, as well as migration options and paths for Oracle and non-Oracle databases to Oracle Exadata are covered. This Oracle Press guide also discusses architecture, administration, maintenance, monitoring, and tuning of Oracle Exadata Storage Servers and the Sun Oracle Database Machine. If your company is considering Exadata, or if you need more horsepower out of your data warehouse, I highly recommend grabbing a copy of this book next week.

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• Orchestrating the Virtual Enterprise, Part II

  - by Kathryn Perry

  A guest post by Jon Chorley, Oracle's CSO & Vice President, SCM Product Strategy Almost everyone has ordered from Amazon.com at one time or another. Our orders are as likely to be fulfilled by third parties as they are by Amazon itself. To deliver the order promptly and efficiently, Amazon has to send it to the right fulfillment location and know the availability in that location. It needs to be able to track status of the fulfillment and deal with exceptions. As a virtual enterprise, Amazon's operations, using thousands of trading partners, requires a very different approach to fulfillment than the traditional 'take an order and ship it from your own warehouse' model. Amazon had no choice but to develop a complex, expensive and custom solution to tackle this problem as there used to be no product solution available. Now, other companies who want to follow similar models have a better off-the-shelf choice -- Oracle Distributed Order Orchestration (DOO).  Consider how another of our customers is using our distributed orchestration solution. This major airplane manufacturer has a highly complex business and interacts regularly with the U.S. Government and major airlines. It sits in the middle of an intricate supply chain and needed to improve visibility across its many different entities. Oracle Fusion DOO gives the company an orchestration mechanism so it could improve quality, speed, flexibility, and consistency without requiring an organ transplant of these highly complex legacy systems. Many retailers face the challenge of dealing with brick and mortar, Web, and reseller channels. They all need to be knitted together into a virtual enterprise experience that is consistent for their customers. When a large U.K. grocer with a strong brick and mortar retail operation added an online business, they turned to Oracle Fusion DOO to bring these entities together. Disturbing the Peace with Acquisitions Quite often a company's ERP system is disrupted when it acquires a new company. An acquisition can inject a new set of processes and systems -- or even introduce an entirely new business like Sun's hardware did at Oracle. This challenge has been a driver for some of our DOO customers. A large power management company is using Oracle Fusion DOO to provide the flexibility to rapidly integrate additional products and services into its central fulfillment operation. The Flip Side of Fulfillment Meanwhile, we haven't ignored similar challenges on the supply side of the equation. Specifically, how to manage complex supply in a flexible way when there are multiple trading parties involved? How to manage the supply to suppliers? How to manage critical components that need to merge in a tier two or tier three supply chain? By investing in supply orchestration solutions for the virtual enterprise, we plan to give users better visibility into their network of suppliers to help them drive down costs. We also think this technology and full orchestration process can be applied to the financial side of organizations. An example is transactions that flow through complex internal structures to minimize tax exposure. We can help companies manage those transactions effectively by thinking about the internal organization as a virtual enterprise and bringing the same solution set to this internal challenge.  The Clear Front Runner No other company is investing in solving the virtual enterprise supply chain issues like Oracle is. Oracle is in a unique position to become the gold standard in this market space. We have the infrastructure of Oracle technology. We already have an Oracle Fusion DOO application which embraces the best of what's required in this area. And we're absolutely committed to extending our Fusion solution to other use cases and delivering even more business value. Jon ChorleyChief Sustainability Officer & Vice President, SCM Product StrategyOracle Corporation

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• SQL Azure: Notes on Building a Shard Technology

  - by Herve Roggero

  In Chapter 10 of the book on SQL Azure (http://www.apress.com/book/view/9781430229612) I am co-authoring, I am digging deeper in what it takes to write a Shard. It's actually a pretty cool exercise, and I wanted to share some thoughts on how I am designing the technology. A Shard is a technology that spreads the load of database requests over multiple databases, as transparently as possible. The type of shard I am building is called a Vertical Partition Shard  (VPS). A VPS is a mechanism by which the data is stored in one or more databases behind the scenes, but your code has no idea at design time which data is in which database. It's like having a mini cloud for records instead of services. Imagine you have three SQL Azure databases that have the same schema (DB1, DB2 and DB3), you would like to issue a SELECT * FROM Users on all three databases, concatenate the results into a single resultset, and order by last name. Imagine you want to ensure your code doesn't need to change if you add a new database to the shard (DB4). Now imagine that you want to make sure all three databases are queried at the same time, in a multi-threaded manner so your code doesn't have to wait for three database calls sequentially. Then, imagine you would like to obtain a breadcrumb (in the form of a new, virtual column) that gives you a hint as to which database a record came from, so that you could update it if needed. Now imagine all that is done through the standard SqlClient library... and you have the Shard I am currently building. Here are some lessons learned and techniques I am using with this shard: Parellel Processing: Querying databases in parallel is not too hard using the Task Parallel Library; all you need is to lock your resources when needed Deleting/Updating Data: That's not too bad either as long as you have a breadcrumb. However it becomes more difficult if you need to update a single record and you don't know in which database it is. Inserting Data: I am using a round-robin approach in which each new insert request is directed to the next database in the shard. Not sure how to deal with Bulk Loads just yet... Shard Databases:  I use a static collection of SqlConnection objects which needs to be loaded once; from there on all the Shard commands use this collection Extension Methods: In order to make it look like the Shard commands are part of the SqlClient class I use extension methods. For example I added ExecuteShardQuery and ExecuteShardNonQuery methods to SqlClient. Exceptions: Capturing exceptions in a multi-threaded code is interesting... but I kept it simple for now. I am using the ConcurrentQueue to store my exceptions. Database GUID: Every database in the shard is given a GUID, which is calculated based on the connection string's values. DataTable. The Shard methods return a DataTable object which can be bound to objects.  I will be sharing the code soon as an open-source project in CodePlex. Please stay tuned on twitter to know when it will be available (@hroggero). Or check www.bluesyntax.net for updates on the shard. Thanks!

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• Windows Azure Service Bus Scatter-Gather Implementation

  - by Alan Smith

  One of the more challenging enterprise integration patterns that developers may wish to implement is the Scatter-Gather pattern. In this article I will show the basic implementation of a scatter-gather pattern using the topic-subscription model of the windows azure service bus. I’ll be using the implementation in demos, and also as a lab in my training courses, and the pattern will also be included in the next release of my free e-book the “Windows Azure Service Bus Developer Guide”. The Scatter-Gather pattern answers the following scenario. How do you maintain the overall message flow when a message needs to be sent to multiple recipients, each of which may send a reply? Use a Scatter-Gather that broadcasts a message to multiple recipients and re-aggregates the responses back into a single message. The Enterprise Integration Patterns website provides a description of the Scatter-Gather pattern here.   The scatter-gather pattern uses a composite of the publish-subscribe channel pattern and the aggregator pattern. The publish-subscribe channel is used to broadcast messages to a number of receivers, and the aggregator is used to gather the response messages and aggregate them together to form a single message. Scatter-Gather Scenario The scenario for this scatter-gather implementation is an application that allows users to answer questions in a poll based voting scenario. A poll manager application will be used to broadcast questions to users, the users will use a voting application that will receive and display the questions and send the votes back to the poll manager. The poll manager application will receive the users’ votes and aggregate them together to display the results. The scenario should be able to scale to support a large number of users.   Scatter-Gather Implementation The diagram below shows the overall architecture for the scatter-gather implementation.       Messaging Entities Looking at the scatter-gather pattern diagram it can be seen that the topic-subscription architecture is well suited for broadcasting a message to a number of subscribers. The poll manager application can send the question messages to a topic, and each voting application can receive the question message on its own subscription. The static limit of 2,000 subscriptions per topic in the current release means that 2,000 voting applications can receive question messages and take part in voting. The vote messages can then be sent to the poll manager application using a queue. The voting applications will send their vote messages to the queue, and the poll manager will receive and process the vote messages. The questions topic and answer queue are created using the Windows Azure Developer Portal. Each instance of the voting application will create its own subscription in the questions topic when it starts, allowing the question messages to be broadcast to all subscribing voting applications. Data Contracts Two simple data contracts will be used to serialize the questions and votes as brokered messages. The code for these is shown below.   [DataContract] public class Question {     [DataMember]     public string QuestionText { get; set; } }     To keep the implementation of the voting functionality simple and focus on the pattern implementation, the users can only vote yes or no to the questions.   [DataContract] public class Vote {     [DataMember]     public string QuestionText { get; set; }       [DataMember]     public bool IsYes { get; set; } }     Poll Manager Application The poll manager application has been implemented as a simple WPF application; the user interface is shown below. A question can be entered in the text box, and sent to the topic by clicking the Add button. The topic and subscriptions used for broadcasting the messages are shown in a TreeView control. The questions that have been broadcast and the resulting votes are shown in a ListView control. When the application is started any existing subscriptions are cleared form the topic, clients are then created for the questions topic and votes queue, along with background workers for receiving and processing the vote messages, and updating the display of subscriptions.   public MainWindow() {     InitializeComponent();       // Create a new results list and data bind it.     Results = new ObservableCollection<Result>();     lsvResults.ItemsSource = Results;       // Create a token provider with the relevant credentials.     TokenProvider credentials =         TokenProvider.CreateSharedSecretTokenProvider         (AccountDetails.Name, AccountDetails.Key);       // Create a URI for the serivce bus.     Uri serviceBusUri = ServiceBusEnvironment.CreateServiceUri         ("sb", AccountDetails.Namespace, string.Empty);       // Clear out any old subscriptions.     NamespaceManager = new NamespaceManager(serviceBusUri, credentials);     IEnumerable<SubscriptionDescription> subs =         NamespaceManager.GetSubscriptions(AccountDetails.ScatterGatherTopic);     foreach (SubscriptionDescription sub in subs)     {         NamespaceManager.DeleteSubscription(sub.TopicPath, sub.Name);     }       // Create the MessagingFactory     MessagingFactory factory = MessagingFactory.Create(serviceBusUri, credentials);       // Create the topic and queue clients.     ScatterGatherTopicClient =         factory.CreateTopicClient(AccountDetails.ScatterGatherTopic);     ScatterGatherQueueClient =         factory.CreateQueueClient(AccountDetails.ScatterGatherQueue);       // Start the background worker threads.     VotesBackgroundWorker = new BackgroundWorker();     VotesBackgroundWorker.DoWork += new DoWorkEventHandler(ReceiveMessages);     VotesBackgroundWorker.RunWorkerAsync();       SubscriptionsBackgroundWorker = new BackgroundWorker();     SubscriptionsBackgroundWorker.DoWork += new DoWorkEventHandler(UpdateSubscriptions);     SubscriptionsBackgroundWorker.RunWorkerAsync(); }     When the poll manager user nters a question in the text box and clicks the Add button a question message is created and sent to the topic. This message will be broadcast to all the subscribing voting applications. An instance of the Result class is also created to keep track of the votes cast, this is then added to an observable collection named Results, which is data-bound to the ListView control.   private void btnAddQuestion_Click(object sender, RoutedEventArgs e) {     // Create a new result for recording votes.     Result result = new Result()     {         Question = txtQuestion.Text     };     Results.Add(result);       // Send the question to the topic     Question question = new Question()     {         QuestionText = result.Question     };     BrokeredMessage msg = new BrokeredMessage(question);     ScatterGatherTopicClient.Send(msg);       txtQuestion.Text = ""; }     The Results class is implemented as follows.   public class Result : INotifyPropertyChanged {     public string Question { get; set; }       private int m_YesVotes;     private int m_NoVotes;       public event PropertyChangedEventHandler PropertyChanged;       public int YesVotes     {         get { return m_YesVotes; }         set         {             m_YesVotes = value;             NotifyPropertyChanged("YesVotes");         }     }       public int NoVotes     {         get { return m_NoVotes; }         set         {             m_NoVotes = value;             NotifyPropertyChanged("NoVotes");         }     }       private void NotifyPropertyChanged(string prop)     {         if(PropertyChanged != null)         {             PropertyChanged(this, new PropertyChangedEventArgs(prop));         }     } }     The INotifyPropertyChanged interface is implemented so that changes to the number of yes and no votes will be updated in the ListView control. Receiving the vote messages from the voting applications is done asynchronously, using a background worker thread.   // This runs on a background worker. private void ReceiveMessages(object sender, DoWorkEventArgs e) {     while (true)     {         // Receive a vote message from the queue         BrokeredMessage msg = ScatterGatherQueueClient.Receive();         if (msg != null)         {             // Deserialize the message.             Vote vote = msg.GetBody<Vote>();               // Update the results.             foreach (Result result in Results)             {                 if (result.Question.Equals(vote.QuestionText))                 {                     if (vote.IsYes)                     {                         result.YesVotes++;                     }                     else                     {                         result.NoVotes++;                     }                     break;                 }             }               // Mark the message as complete.             msg.Complete();         }       } }     When a vote message is received, the result that matches the vote question is updated with the vote from the user. The message is then marked as complete. A second background thread is used to update the display of subscriptions in the TreeView, with a dispatcher used to update the user interface. // This runs on a background worker. private void UpdateSubscriptions(object sender, DoWorkEventArgs e) {     while (true)     {         // Get a list of subscriptions.         IEnumerable<SubscriptionDescription> subscriptions =             NamespaceManager.GetSubscriptions(AccountDetails.ScatterGatherTopic);           // Update the user interface.         SimpleDelegate setQuestion = delegate()         {             trvSubscriptions.Items.Clear();             TreeViewItem topicItem = new TreeViewItem()             {                 Header = AccountDetails.ScatterGatherTopic             };               foreach (SubscriptionDescription subscription in subscriptions)             {                 TreeViewItem subscriptionItem = new TreeViewItem()                 {                     Header = subscription.Name                 };                 topicItem.Items.Add(subscriptionItem);             }             trvSubscriptions.Items.Add(topicItem);               topicItem.ExpandSubtree();         };         this.Dispatcher.BeginInvoke(DispatcherPriority.Send, setQuestion);           Thread.Sleep(3000);     } }       Voting Application The voting application is implemented as another WPF application. This one is more basic, and allows the user to vote “Yes” or “No” for the questions sent by the poll manager application. The user interface for that application is shown below. When an instance of the voting application is created it will create a subscription in the questions topic using a GUID as the subscription name. The application can then receive copies of every question message that is sent to the topic. Clients for the new subscription and the votes queue are created, along with a background worker to receive the question messages. The voting application is set to receiving mode, meaning it is ready to receive a question message from the subscription.   public MainWindow() {     InitializeComponent();       // Set the mode to receiving.     IsReceiving = true;       // Create a token provider with the relevant credentials.     TokenProvider credentials =         TokenProvider.CreateSharedSecretTokenProvider         (AccountDetails.Name, AccountDetails.Key);       // Create a URI for the serivce bus.     Uri serviceBusUri = ServiceBusEnvironment.CreateServiceUri         ("sb", AccountDetails.Namespace, string.Empty);       // Create the MessagingFactory     MessagingFactory factory = MessagingFactory.Create(serviceBusUri, credentials);       // Create a subcription for this instance     NamespaceManager mgr = new NamespaceManager(serviceBusUri, credentials);     string subscriptionName = Guid.NewGuid().ToString();     mgr.CreateSubscription(AccountDetails.ScatterGatherTopic, subscriptionName);       // Create the subscription and queue clients.     ScatterGatherSubscriptionClient = factory.CreateSubscriptionClient         (AccountDetails.ScatterGatherTopic, subscriptionName);     ScatterGatherQueueClient =         factory.CreateQueueClient(AccountDetails.ScatterGatherQueue);       // Start the background worker thread.     BackgroundWorker = new BackgroundWorker();     BackgroundWorker.DoWork += new DoWorkEventHandler(ReceiveMessages);     BackgroundWorker.RunWorkerAsync(); }     I took the inspiration for creating the subscriptions in the voting application from the chat application that uses topics and subscriptions blogged by Ovais Akhter here. The method that receives the question messages runs on a background thread. If the application is in receive mode, a question message will be received from the subscription, the question will be displayed in the user interface, the voting buttons enabled, and IsReceiving set to false to prevent more questing from being received before the current one is answered.   // This runs on a background worker. private void ReceiveMessages(object sender, DoWorkEventArgs e) {     while (true)     {         if (IsReceiving)         {             // Receive a question message from the topic.             BrokeredMessage msg = ScatterGatherSubscriptionClient.Receive();             if (msg != null)             {                 // Deserialize the message.                 Question question = msg.GetBody<Question>();                   // Update the user interface.                 SimpleDelegate setQuestion = delegate()                 {                     lblQuestion.Content = question.QuestionText;                     btnYes.IsEnabled = true;                     btnNo.IsEnabled = true;                 };                 this.Dispatcher.BeginInvoke(DispatcherPriority.Send, setQuestion);                 IsReceiving = false;                   // Mark the message as complete.                 msg.Complete();             }         }         else         {             Thread.Sleep(1000);         }     } }     When the user clicks on the Yes or No button, the btnVote_Click method is called. This will create a new Vote data contract with the appropriate question and answer and send the message to the poll manager application using the votes queue. The user voting buttons are then disabled, the question text cleared, and the IsReceiving flag set to true to allow a new message to be received.   private void btnVote_Click(object sender, RoutedEventArgs e) {     // Create a new vote.     Vote vote = new Vote()     {         QuestionText = (string)lblQuestion.Content,         IsYes = ((sender as Button).Content as string).Equals("Yes")     };       // Send the vote message.     BrokeredMessage msg = new BrokeredMessage(vote);     ScatterGatherQueueClient.Send(msg);       // Update the user interface.     lblQuestion.Content = "";     btnYes.IsEnabled = false;     btnNo.IsEnabled = false;     IsReceiving = true; }     Testing the Application In order to test the application, an instance of the poll manager application is started; the user interface is shown below. As no instances of the voting application have been created there are no subscriptions present in the topic. When an instance of the voting application is created the subscription will be displayed in the poll manager. Now that a voting application is subscribing, a questing can be sent from the poll manager application. When the message is sent to the topic, the voting application will receive the message and display the question. The voter can then answer the question by clicking on the appropriate button. The results of the vote are updated in the poll manager application. When two more instances of the voting application are created, the poll manager will display the new subscriptions. More questions can then be broadcast to the voting applications. As the question messages are queued up in the subscription for each voting application, the users can answer the questions in their own time. The vote messages will be received by the poll manager application and aggregated to display the results. The screenshots of the applications part way through voting are shown below. The messages for each voting application are queued up in sequence on the voting application subscriptions, allowing the questions to be answered at different speeds by the voters.

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• Azure &ndash; Part 6 &ndash; Blob Storage Service

  - by Shaun

  When migrate your application onto the Azure one of the biggest concern would be the external files. In the original way we understood and ensure which machine and folder our application (website or web service) is located in. So that we can use the MapPath or some other methods to read and write the external files for example the images, text files or the xml files, etc. But things have been changed when we deploy them on Azure. Azure is not a server, or a single machine, it’s a set of virtual server machine running under the Azure OS. And even worse, your application might be moved between thses machines. So it’s impossible to read or write the external files on Azure. In order to resolve this issue the Windows Azure provides another storage serviec – Blob, for us. Different to the table service, the blob serivce is to be used to store text and binary data rather than the structured data. It provides two types of blobs: Block Blobs and Page Blobs. Block Blobs are optimized for streaming. They are comprised of blocks, each of which is identified by a block ID and each block can be a maximum of 4 MB in size. Page Blobs are are optimized for random read/write operations and provide the ability to write to a range of bytes in a blob. They are a collection of pages. The maximum size for a page blob is 1 TB.   In the managed library the Azure SDK allows us to communicate with the blobs through these classes CloudBlobClient, CloudBlobContainer, CloudBlockBlob and the CloudPageBlob. Similar with the table service managed library, the CloudBlobClient allows us to reach the blob service by passing our storage account information and also responsible for creating the blob container is not exist. Then from the CloudBlobContainer we can save or load the block blobs and page blobs into the CloudBlockBlob and the CloudPageBlob classes.   Let’s improve our exmaple in the previous posts – add a service method allows the user to upload the logo image. In the server side I created a method name UploadLogo with 2 parameters: email and image. Then I created the storage account from the config file. I also add the validation to ensure that the email passed in is valid. 1: var storageAccount = CloudStorageAccount.FromConfigurationSetting("DataConnectionString"); 2: var accountContext = new DynamicDataContext<Account>(storageAccount); 3:  4: // validation 5: var accountNumber = accountContext.Load() 6: .Where(a => a.Email == email) 7: .ToList() 8: .Count; 9: if (accountNumber <= 0) 10: { 11: throw new ApplicationException(string.Format("Cannot find the account with the email {0}.", email)); 12: } Then there are three steps for saving the image into the blob service. First alike the table service I created the container with a unique name and create it if it’s not exist. 1: // create the blob container for account logos if not exist 2: CloudBlobClient blobStorage = storageAccount.CreateCloudBlobClient(); 3: CloudBlobContainer container = blobStorage.GetContainerReference("account-logo"); 4: container.CreateIfNotExist(); Then, since in this example I will just send the blob access URL back to the client so I need to open the read permission on that container. 1: // configure blob container for public access 2: BlobContainerPermissions permissions = container.GetPermissions(); 3: permissions.PublicAccess = BlobContainerPublicAccessType.Container; 4: container.SetPermissions(permissions); And at the end I combine the blob resource name from the input file name and Guid, and then save it to the block blob by using the UploadByteArray method. Finally I returned the URL of this blob back to the client side. 1: // save the blob into the blob service 2: string uniqueBlobName = string.Format("{0}_{1}.jpg", email, Guid.NewGuid().ToString()); 3: CloudBlockBlob blob = container.GetBlockBlobReference(uniqueBlobName); 4: blob.UploadByteArray(image); 5:  6: return blob.Uri.ToString(); Let’s update a bit on the client side application and see the result. Here I just use my simple console application to let the user input the email and the file name of the image. If it’s OK it will show the URL of the blob on the server side so that we can see it through the web browser. Then we can see the logo I’ve just uploaded through the URL here. You may notice that the blob URL was based on the container name and the blob unique name. In the document of the Azure SDK there’s a page for the rule of naming them, but I think the simple rule would be – they must be valid as an URL address. So that you cannot name the container with dot or slash as it will break the ADO.Data Service routing rule. For exmaple if you named the blob container as Account.Logo then it will throw an exception says 400 Bad Request.   Summary In this short entity I covered the simple usage of the blob service to save the images onto Azure. Since the Azure platform does not support the file system we have to migrate our code for reading/writing files to the blob service before deploy it to Azure. In order to reducing this effort Microsoft provided a new approch named Drive, which allows us read and write the NTFS files just likes what we did before. It’s built up on the blob serivce but more properly for files accessing. I will discuss more about it in the next post.   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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• Solving Kaggle’s Bike Sharing Demand Machine Learning Problem

  - by Gopinath

  Kaggle.com hosts a lot of interesting machine learning problems online and thousands of its members compete to solve them for a bounty. Problems hosted on Kaggle has varying complexity to accomodate newbies to rock star developers – few problems are good enough for  newbies to learn basics of machine learning and few of them challenge the best of machine learning developers. I’m learning basics of machine learning for the past few weeks and had an opportunity to solve Kaggel’s Bike Sharing Demand problem. Bike Sharing systems allows customers to rent a bike (or a cycle as it is called in many part of the world) for several hours and return them back . The problem provides historical information about the demand for bike sharing business and we need to forecast the demand. For more information on the problem, visit Kaggle.com website. Here is the solution I written using random forests algorithm using R programming language and you can download the source code from github.  With this solution I was able to score RMSLE of 0.70117, which placed me somewhere in the mid of the leader board.  This is the best score I could get by spending 4 hours of my time. Please feel free to fork the code and improve it.   Get Kaggle Bike Sharing Demand solution code from GitHub

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• BSOD trying to migrate Windows XP from a physical to a virtual machine

  - by pauldoo

  I am attempting to migrate a Windows XP Home installation from a physical machine to a virtual machine. The physical machine has two hard disks; the first is 250GB containing the "C:", the second is 1TB containing "D:". I'd like to create a new virtual machine stored on the D:, which is a copy of the Windows XP Home installation that is currently on the C:. (This will leave the 250GB drive clear for me to install a fresh copy of Windows 7, and still be able to access the old XP installation if necessary.) The first method I tried was to follow the instructions here: http://www.virtualbox.org/wiki/Migrate_Windows I booted up from an Ubuntu Live CD in order to execute the Linux commands whilst the Windows system wasn't running. With this method the virtual machine would always blue screen on startup with a "STOP 0x0000007B" message. The instructions above say to try a "repair install" using the Windows XP disc. Unfortunately for me my XP disc is scratched and will not boot so I was unable to try a repair install. The second method I tried was to use "VMWare Converter Standalone Client". This tool executed without any errors, but again produced a virtual machine that blue screens on startup with the same "STOP" message. Are there any other methods to move the Windows XP installation into a virtual machine? I think next I will try some more manual process to create the cloned virtual machine. I think I will try installing a fresh copy of Windows XP to a virtual machine, then once that is booting OK I will ntfsclone the source C: partition over the top. Perhaps this will fix the booting problems if the issue is related to the MBR or partition table in some way.

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• Virtual host is not working in Ubuntu 14 VPS using XAMPP 1.8.3

  - by viral4ever

  I am using XAMPP as server in ubuntu 14.04 VPS of digitalocean. I tried to setup virtual hosts. But it is not working and I am getting 403 error of access denied. I changed files too. My files with changes are /opt/lampp/etc/httpd.conf # # This is the main Apache HTTP server configuration file. It contains the # configuration directives that give the server its instructions. # See <URL:http://httpd.apache.org/docs/trunk/> for detailed information. # In particular, see # <URL:http://httpd.apache.org/docs/trunk/mod/directives.html> # for a discussion of each configuration directive. # # Do NOT simply read the instructions in here without understanding # what they do. They're here only as hints or reminders. If you are unsure # consult the online docs. You have been warned. # # Configuration and logfile names: If the filenames you specify for many # of the server's control files begin with "/" (or "drive:/" for Win32), the # server will use that explicit path. If the filenames do *not* begin # with "/", the value of ServerRoot is prepended -- so 'log/access_log' # with ServerRoot set to '/www' will be interpreted by the # server as '/www/log/access_log', where as '/log/access_log' will be # interpreted as '/log/access_log'. # # ServerRoot: The top of the directory tree under which the server's # configuration, error, and log files are kept. # # Do not add a slash at the end of the directory path. If you point # ServerRoot at a non-local disk, be sure to specify a local disk on the # Mutex directive, if file-based mutexes are used. If you wish to share the # same ServerRoot for multiple httpd daemons, you will need to change at # least PidFile. # ServerRoot "/opt/lampp" # # Mutex: Allows you to set the mutex mechanism and mutex file directory # for individual mutexes, or change the global defaults # # Uncomment and change the directory if mutexes are file-based and the default # mutex file directory is not on a local disk or is not appropriate for some # other reason. # # Mutex default:logs # # Listen: Allows you to bind Apache to specific IP addresses and/or # ports, instead of the default. See also the <VirtualHost> # directive. # # Change this to Listen on specific IP addresses as shown below to # prevent Apache from glomming onto all bound IP addresses. # #Listen 12.34.56.78:80 Listen 80 # # Dynamic Shared Object (DSO) Support # # To be able to use the functionality of a module which was built as a DSO you # have to place corresponding `LoadModule' lines at this location so the # directives contained in it are actually available _before_ they are used. # Statically compiled modules (those listed by `httpd -l') do not need # to be loaded here. # # Example: # LoadModule foo_module modules/mod_foo.so # LoadModule authn_file_module modules/mod_authn_file.so LoadModule authn_dbm_module modules/mod_authn_dbm.so LoadModule authn_anon_module modules/mod_authn_anon.so LoadModule authn_dbd_module modules/mod_authn_dbd.so LoadModule authn_socache_module modules/mod_authn_socache.so LoadModule authn_core_module modules/mod_authn_core.so LoadModule authz_host_module modules/mod_authz_host.so LoadModule authz_groupfile_module modules/mod_authz_groupfile.so LoadModule authz_user_module modules/mod_authz_user.so LoadModule authz_dbm_module modules/mod_authz_dbm.so LoadModule authz_owner_module modules/mod_authz_owner.so LoadModule authz_dbd_module modules/mod_authz_dbd.so LoadModule authz_core_module modules/mod_authz_core.so LoadModule authnz_ldap_module modules/mod_authnz_ldap.so LoadModule access_compat_module modules/mod_access_compat.so LoadModule auth_basic_module modules/mod_auth_basic.so LoadModule auth_form_module modules/mod_auth_form.so LoadModule auth_digest_module modules/mod_auth_digest.so LoadModule allowmethods_module modules/mod_allowmethods.so LoadModule file_cache_module modules/mod_file_cache.so LoadModule cache_module modules/mod_cache.so LoadModule cache_disk_module modules/mod_cache_disk.so LoadModule socache_shmcb_module modules/mod_socache_shmcb.so LoadModule socache_dbm_module modules/mod_socache_dbm.so LoadModule socache_memcache_module modules/mod_socache_memcache.so LoadModule dbd_module modules/mod_dbd.so LoadModule bucketeer_module modules/mod_bucketeer.so LoadModule dumpio_module modules/mod_dumpio.so LoadModule echo_module modules/mod_echo.so LoadModule case_filter_module modules/mod_case_filter.so LoadModule case_filter_in_module modules/mod_case_filter_in.so LoadModule buffer_module modules/mod_buffer.so LoadModule ratelimit_module modules/mod_ratelimit.so LoadModule reqtimeout_module modules/mod_reqtimeout.so LoadModule ext_filter_module modules/mod_ext_filter.so LoadModule request_module modules/mod_request.so LoadModule include_module modules/mod_include.so LoadModule filter_module modules/mod_filter.so LoadModule substitute_module modules/mod_substitute.so LoadModule sed_module modules/mod_sed.so LoadModule charset_lite_module modules/mod_charset_lite.so LoadModule deflate_module modules/mod_deflate.so LoadModule mime_module modules/mod_mime.so LoadModule ldap_module modules/mod_ldap.so LoadModule log_config_module modules/mod_log_config.so LoadModule log_debug_module modules/mod_log_debug.so LoadModule logio_module modules/mod_logio.so LoadModule env_module modules/mod_env.so LoadModule mime_magic_module modules/mod_mime_magic.so LoadModule cern_meta_module modules/mod_cern_meta.so LoadModule expires_module modules/mod_expires.so LoadModule headers_module modules/mod_headers.so LoadModule usertrack_module modules/mod_usertrack.so LoadModule unique_id_module modules/mod_unique_id.so LoadModule setenvif_module modules/mod_setenvif.so LoadModule version_module modules/mod_version.so LoadModule remoteip_module modules/mod_remoteip.so LoadModule proxy_module modules/mod_proxy.so LoadModule proxy_connect_module modules/mod_proxy_connect.so LoadModule proxy_ftp_module modules/mod_proxy_ftp.so LoadModule proxy_http_module modules/mod_proxy_http.so LoadModule proxy_fcgi_module modules/mod_proxy_fcgi.so LoadModule proxy_scgi_module modules/mod_proxy_scgi.so LoadModule proxy_ajp_module modules/mod_proxy_ajp.so LoadModule proxy_balancer_module modules/mod_proxy_balancer.so LoadModule proxy_express_module modules/mod_proxy_express.so LoadModule session_module modules/mod_session.so LoadModule session_cookie_module modules/mod_session_cookie.so LoadModule session_dbd_module modules/mod_session_dbd.so LoadModule slotmem_shm_module modules/mod_slotmem_shm.so LoadModule ssl_module modules/mod_ssl.so LoadModule lbmethod_byrequests_module modules/mod_lbmethod_byrequests.so LoadModule lbmethod_bytraffic_module modules/mod_lbmethod_bytraffic.so LoadModule lbmethod_bybusyness_module modules/mod_lbmethod_bybusyness.so LoadModule lbmethod_heartbeat_module modules/mod_lbmethod_heartbeat.so LoadModule unixd_module modules/mod_unixd.so LoadModule dav_module modules/mod_dav.so LoadModule status_module modules/mod_status.so LoadModule autoindex_module modules/mod_autoindex.so LoadModule info_module modules/mod_info.so LoadModule suexec_module modules/mod_suexec.so LoadModule cgi_module modules/mod_cgi.so LoadModule cgid_module modules/mod_cgid.so LoadModule dav_fs_module modules/mod_dav_fs.so LoadModule vhost_alias_module modules/mod_vhost_alias.so LoadModule negotiation_module modules/mod_negotiation.so LoadModule dir_module modules/mod_dir.so LoadModule actions_module modules/mod_actions.so LoadModule speling_module modules/mod_speling.so LoadModule userdir_module modules/mod_userdir.so LoadModule alias_module modules/mod_alias.so LoadModule rewrite_module modules/mod_rewrite.so <IfDefine JUSTTOMAKEAPXSHAPPY> LoadModule php4_module modules/libphp4.so LoadModule php5_module modules/libphp5.so </IfDefine> <IfModule unixd_module> # # If you wish httpd to run as a different user or group, you must run # httpd as root initially and it will switch. # # User/Group: The name (or #number) of the user/group to run httpd as. # It is usually good practice to create a dedicated user and group for # running httpd, as with most system services. # User root Group www </IfModule> # 'Main' server configuration # # The directives in this section set up the values used by the 'main' # server, which responds to any requests that aren't handled by a # <VirtualHost> definition. These values also provide defaults for # any <VirtualHost> containers you may define later in the file. # # All of these directives may appear inside <VirtualHost> containers, # in which case these default settings will be overridden for the # virtual host being defined. # # # ServerAdmin: Your address, where problems with the server should be # e-mailed. This address appears on some server-generated pages, such # as error documents. e.g. [email protected] # ServerAdmin [email protected] # # ServerName gives the name and port that the server uses to identify itself. # This can often be determined automatically, but we recommend you specify # it explicitly to prevent problems during startup. # # If your host doesn't have a registered DNS name, enter its IP address here. # #ServerName www.example.com:@@Port@@ # XAMPP ServerName localhost # # Deny access to the entirety of your server's filesystem. You must # explicitly permit access to web content directories in other # <Directory> blocks below. # <Directory /> AllowOverride none Require all denied </Directory> # # Note that from this point forward you must specifically allow # particular features to be enabled - so if something's not working as # you might expect, make sure that you have specifically enabled it # below. # # # DocumentRoot: The directory out of which you will serve your # documents. By default, all requests are taken from this directory, but # symbolic links and aliases may be used to point to other locations. # DocumentRoot "/opt/lampp/htdocs" <Directory "/opt/lampp/htdocs"> # # Possible values for the Options directive are "None", "All", # or any combination of: # Indexes Includes FollowSymLinks SymLinksifOwnerMatch ExecCGI MultiViews # # Note that "MultiViews" must be named *explicitly* --- "Options All" # doesn't give it to you. # # The Options directive is both complicated and important. Please see # http://httpd.apache.org/docs/trunk/mod/core.html#options # for more information. # #Options Indexes FollowSymLinks # XAMPP Options Indexes FollowSymLinks ExecCGI Includes # # AllowOverride controls what directives may be placed in .htaccess files. # It can be "All", "None", or any combination of the keywords: # Options FileInfo AuthConfig Limit # #AllowOverride None # since XAMPP 1.4: AllowOverride All # # Controls who can get stuff from this server. # Require all granted </Directory> # # DirectoryIndex: sets the file that Apache will serve if a directory # is requested. # <IfModule dir_module> #DirectoryIndex index.html # XAMPP DirectoryIndex index.html index.html.var index.php index.php3 index.php4 </IfModule> # # The following lines prevent .htaccess and .htpasswd files from being # viewed by Web clients. # <Files ".ht*"> Require all denied </Files> # # ErrorLog: The location of the error log file. # If you do not specify an ErrorLog directive within a <VirtualHost> # container, error messages relating to that virtual host will be # logged here. If you *do* define an error logfile for a <VirtualHost> # container, that host's errors will be logged there and not here. # ErrorLog "logs/error_log" # # LogLevel: Control the number of messages logged to the error_log. # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. # LogLevel warn <IfModule log_config_module> # # The following directives define some format nicknames for use with # a CustomLog directive (see below). # LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined LogFormat "%h %l %u %t \"%r\" %>s %b" common <IfModule logio_module> # You need to enable mod_logio.c to use %I and %O LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" %I %O" combinedio </IfModule> # # The location and format of the access logfile (Common Logfile Format). # If you do not define any access logfiles within a <VirtualHost> # container, they will be logged here. Contrariwise, if you *do* # define per-<VirtualHost> access logfiles, transactions will be # logged therein and *not* in this file. # CustomLog "logs/access_log" common # # If you prefer a logfile with access, agent, and referer information # (Combined Logfile Format) you can use the following directive. # #CustomLog "logs/access_log" combined </IfModule> <IfModule alias_module> # # Redirect: Allows you to tell clients about documents that used to # exist in your server's namespace, but do not anymore. The client # will make a new request for the document at its new location. # Example: # Redirect permanent /foo http://www.example.com/bar # # Alias: Maps web paths into filesystem paths and is used to # access content that does not live under the DocumentRoot. # Example: # Alias /webpath /full/filesystem/path # # If you include a trailing / on /webpath then the server will # require it to be present in the URL. You will also likely # need to provide a <Directory> section to allow access to # the filesystem path. # # ScriptAlias: This controls which directories contain server scripts. # ScriptAliases are essentially the same as Aliases, except that # documents in the target directory are treated as applications and # run by the server when requested rather than as documents sent to the # client. The same rules about trailing "/" apply to ScriptAlias # directives as to Alias. # ScriptAlias /cgi-bin/ "/opt/lampp/cgi-bin/" </IfModule> <IfModule cgid_module> # # ScriptSock: On threaded servers, designate the path to the UNIX # socket used to communicate with the CGI daemon of mod_cgid. # #Scriptsock logs/cgisock </IfModule> # # "/opt/lampp/cgi-bin" should be changed to whatever your ScriptAliased # CGI directory exists, if you have that configured. # <Directory "/opt/lampp/cgi-bin"> AllowOverride None Options None Require all granted </Directory> <IfModule mime_module> # # TypesConfig points to the file containing the list of mappings from # filename extension to MIME-type. # TypesConfig etc/mime.types # # AddType allows you to add to or override the MIME configuration # file specified in TypesConfig for specific file types. # #AddType application/x-gzip .tgz # # AddEncoding allows you to have certain browsers uncompress # information on the fly. Note: Not all browsers support this. # #AddEncoding x-compress .Z #AddEncoding x-gzip .gz .tgz # # If the AddEncoding directives above are commented-out, then you # probably should define those extensions to indicate media types: # AddType application/x-compress .Z AddType application/x-gzip .gz .tgz # # AddHandler allows you to map certain file extensions to "handlers": # actions unrelated to filetype. These can be either built into the server # or added with the Action directive (see below) # # To use CGI scripts outside of ScriptAliased directories: # (You will also need to add "ExecCGI" to the "Options" directive.) # #AddHandler cgi-script .cgi # XAMPP, since LAMPP 0.9.8: AddHandler cgi-script .cgi .pl # For type maps (negotiated resources): #AddHandler type-map var # # Filters allow you to process content before it is sent to the client. # # To parse .shtml files for server-side includes (SSI): # (You will also need to add "Includes" to the "Options" directive.) # # XAMPP AddType text/html .shtml AddOutputFilter INCLUDES .shtml </IfModule> # # The mod_mime_magic module allows the server to use various hints from the # contents of the file itself to determine its type. The MIMEMagicFile # directive tells the module where the hint definitions are located. # #MIMEMagicFile etc/magic # # Customizable error responses come in three flavors: # 1) plain text 2) local redirects 3) external redirects # # Some examples: #ErrorDocument 500 "The server made a boo boo." #ErrorDocument 404 /missing.html #ErrorDocument 404 "/cgi-bin/missing_handler.pl" #ErrorDocument 402 http://www.example.com/subscription_info.html # # # MaxRanges: Maximum number of Ranges in a request before # returning the entire resource, or one of the special # values 'default', 'none' or 'unlimited'. # Default setting is to accept 200 Ranges. #MaxRanges unlimited # # EnableMMAP and EnableSendfile: On systems that support it, # memory-mapping or the sendfile syscall may be used to deliver # files. This usually improves server performance, but must # be turned off when serving from networked-mounted # filesystems or if support for these functions is otherwise # broken on your system. # Defaults: EnableMMAP On, EnableSendfile Off # EnableMMAP off EnableSendfile off # Supplemental configuration # # The configuration files in the etc/extra/ directory can be # included to add extra features or to modify the default configuration of # the server, or you may simply copy their contents here and change as # necessary. # Server-pool management (MPM specific) #Include etc/extra/httpd-mpm.conf # Multi-language error messages Include etc/extra/httpd-multilang-errordoc.conf # Fancy directory listings Include etc/extra/httpd-autoindex.conf # Language settings #Include etc/extra/httpd-languages.conf # User home directories #Include etc/extra/httpd-userdir.conf # Real-time info on requests and configuration #Include etc/extra/httpd-info.conf # Virtual hosts Include etc/extra/httpd-vhosts.conf # Local access to the Apache HTTP Server Manual #Include etc/extra/httpd-manual.conf # Distributed authoring and versioning (WebDAV) #Include etc/extra/httpd-dav.conf # Various default settings Include etc/extra/httpd-default.conf # Configure mod_proxy_html to understand HTML4/XHTML1 <IfModule proxy_html_module> Include etc/extra/proxy-html.conf </IfModule> # Secure (SSL/TLS) connections <IfModule ssl_module> # XAMPP <IfDefine SSL> Include etc/extra/httpd-ssl.conf </IfDefine> </IfModule> # # Note: The following must must be present to support # starting without SSL on platforms with no /dev/random equivalent # but a statically compiled-in mod_ssl. # <IfModule ssl_module> SSLRandomSeed startup builtin SSLRandomSeed connect builtin </IfModule> # XAMPP Include etc/extra/httpd-xampp.conf Include "/opt/lampp/apache2/conf/httpd.conf" I used command shown in this example. I used below lines to change and add group Add group "groupadd www" Add user to group "usermod -aG www root" Change htdocs group "chgrp -R www /opt/lampp/htdocs" Change sitedir group "chgrp -R www /opt/lampp/htdocs/mysite" Change htdocs chmod "chmod 2775 /opt/lampp/htdocs" Change sitedir chmod "chmod 2775 /opt/lampp/htdocs/mysite" And then I changed my vhosts.conf file # Virtual Hosts # # Required modules: mod_log_config # If you want to maintain multiple domains/hostnames on your # machine you can setup VirtualHost containers for them. Most configurations # use only name-based virtual hosts so the server doesn't need to worry about # IP addresses. This is indicated by the asterisks in the directives below. # # Please see the documentation at # <URL:http://httpd.apache.org/docs/2.4/vhosts/> # for further details before you try to setup virtual hosts. # # You may use the command line option '-S' to verify your virtual host # configuration. # # VirtualHost example: # Almost any Apache directive may go into a VirtualHost container. # The first VirtualHost section is used for all requests that do not # match a ServerName or ServerAlias in any <VirtualHost> block. # <VirtualHost *:80> ServerAdmin [email protected] DocumentRoot "/opt/lampp/docs/dummy-host.example.com" ServerName dummy-host.example.com ServerAlias www.dummy-host.example.com ErrorLog "logs/dummy-host.example.com-error_log" CustomLog "logs/dummy-host.example.com-access_log" common </VirtualHost> <VirtualHost *:80> ServerAdmin [email protected] DocumentRoot "/opt/lampp/docs/dummy-host2.example.com" ServerName dummy-host2.example.com ErrorLog "logs/dummy-host2.example.com-error_log" CustomLog "logs/dummy-host2.example.com-access_log" common </VirtualHost> NameVirtualHost * <VirtualHost *> ServerAdmin [email protected] DocumentRoot "/opt/lampp/htdocs/mysite" ServerName mysite.com ServerAlias mysite.com ErrorLog "/opt/lampp/htdocs/mysite/errorlogs" CustomLog "/opt/lampp/htdocs/mysite/customlog" common <Directory "/opt/lampp/htdocs/mysite"> Options Indexes FollowSymLinks Includes ExecCGI AllowOverride All Order Allow,Deny Allow from all Require all granted </Directory> </VirtualHost> but still its not working and I am getting 403 error on my ip and domain however I can access phpmyadmin. If anyone can help me, please help me.

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• ADF updates: mobile virtual developer day & ADF Mobile 1 day Workshop & ADF Architecture TV

  - by JuergenKress

  ADF Mobile Virtual Developer Day Sessions - YouTube ADF Architecture TV – flows WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum WikiTechnorati Tags: adf,ADF Architecture,ADF education,virtual developer day,WebLogic,WebLogic Community,Oracle,OPN,Jürgen Kress

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