Search Results

Search found 47432 results on 1898 pages for 'database link'.

Page 551/1898 | < Previous Page | 547 548 549 550 551 552 553 554 555 556 557 558  | Next Page >

  • Sockets and COBOL

    - by kati
    I have received a job at a hospital which still uses COBOL for all organizational work, the whole (now 20 Terabyte) database (Which was a homebrew in, guess what, COBOL) is filled with the data of every patient since the last 45 (or so) years. So that was my story. Now to my question: Currently, all sockets were (from what I've seen) implemented by COBOL programs writing their data into files. These files then were read out by C++ programs (That was an additional module added in the late 1980s) and using C++ sockets sent to the database. Now this solution has stopped working as they are moving the database from COBOL to COBOL, yes - they didn't use MySQL or so - they implemented a new database - again in COBOL. I asked the guy that worked there before me (hes around 70 now) why the hell someone would do that and he told me that he is so good at COBOL that he doesn't want to write it in any other language. So far so good now my question: How can I implement socket connections in COBOL? I need to create an interface to the external COBOL database located at, for example, 192.168.1.23:283.

    Read the article

  • Parse particular text from an XML string

    - by Dan Sewell
    Hi all, Im writing an app which reads an RSS feed and places items on a map. I need to read the lat and long numbers only from this string: http://www.xxxxxxxxxxxxxx.co.uk/map.aspx?isTrafficAlert=true&lat=53.647351&lon=-1.933506 .This is contained in link tags Im a bit of a programming noob but im writing this in C#/Silverlight using Linq to XML. Shold this text be extrated when parsing or after parsing and sent to a class to do this? Many thanks for your assistance. EDIT. Im going to try and do a regex on this this is where I need to integrate the regex somewhere in this code. I need to take the lat and long from the Link element and seperate it into two variables I can use (the results are part of a foreach loop that creates a list.) var events = from ev in document.Descendants("item") select new { Title = (ev.Element("title").Value), Description = (ev.Element("description").Value), Link = (ev.Element("link").Value), }; Question is im not quite ure where to put the regex (once I work out how to use the regex properly! :-) )

    Read the article

  • Transfer Data between databases with postgres

    - by user227932
    I need to transfer some data from another Database. The old database is called paw1.moviesDB and the new database is paw1. The schema of each table are the following Awards (name of the table)(new DB) Id [PK] Serial Award Nominations (name of the table) (old DB) Id [PK] Serial nominations I want to copy the data from old DB to the new DB.

    Read the article

  • IPhone geo tagging data (SQLite or CoreData)

    - by user267980
    Hi. I'm about to build an app that has a database of places that has a location (lon/lat) and i'm about to build the dataModel. Actualy the app is very simple and all i want is to be able to fetch all places around the user (say in a radius of 30miles). Is it better to user SQLite (is there any geo-spatial extension out there)? I'll have around 5000 places in the database and i'm wondering where i can ask a database without affecting performances.

    Read the article

  • What is the best way to partition large tables in SQL Server?

    - by RyanFetz
    In a recent project the "lead" developer designed a database schema where "larger" tables would be split across two seperate databases with a view on the main database which unioned the two seperate database-tables together. The main database is what the application was driven off of so these tables looked and felt like ordinary tables (except some quirkly things around updating). This seemed like a HUGE performance problem. We do see problems with performance around these tables but nothing to make him change his mind about his design. Just wondering what is the best way to do this, or if it is even worth doing?

    Read the article

  • RabbitMQ as a proxy between a data store and a producer ?

    - by hyperboreean
    I have some code that produces lots of data that should be stored in the database. The problem is that the database can't keep with the data that it gets produced. So I am wondering whether some kind of queuing mechanism would help in this situation - I am thinking in particular at RabiitMQ and whether is feasible to have the data stored in its queues until some consumer gets the data out of it and pushes it to the database. Also, I am not particular interested whether that data made it to the database or not because pretty soon, the same data will be updated.

    Read the article

  • Question regarding xsd

    - by Hima
    I have an application which reads the data from the database, creates an object out of the data, marshalls it into an xml and enqueue the xml to a queue which is producer. The xml is dequeued from the queue by a consumer. I need to use xsds at two different places. For database access while reading the data from the database and For interaction between producer and consumer Can the same xsd be used in both the cases? Or do I need to use different xsds?

    Read the article

  • How to prevent SQL Compact DB to be erased?

    - by Skuta
    Hi, I'm developing an applciation using SQL Compact database in Visual Studio 2008. When I start the application and run the process, the data is being loaded into database for few hours worth of few tens of megabytes. However, when I quite debugging, change something in code (not in DB structure), run the project again, the database is erased. Does anyone know how to prevent this behavior? I need the data to stay in DB to test on it.

    Read the article

  • servlet authentication and further reference to the credentials

    - by user553592
    What I got so far: It all begins with an HTML form which prompts the user for a username and password. From there it post the acquired user/pass to a servlet, GateKeeper. GateKeeper determines if the user/pass combination match any records in the MySQL database. Here is the sql I use: SELECT id FROM Users WHERE username='?' AND password=MD5('?') where the ? indicate information provided the previous HTML form. What I need now: I need some way to store the username and id of the record in the database. GateKeeper redirects the user to a control panel upon success. Therefore, I need a method to reference the username to display simple greetings, etc and also the id so it eliminates unnecessary calls to the database. The control panel may make AJAX calls to Servlets that preform some sort of task to the MySQL database.

    Read the article

  • jquery .siblings do not work

    - by Mango
    Hi i want when the one #box is open the others #box close. Html: <div id="main"> <div id="link">click</div><!--/*div*/--> <div id="box">content1</div><!--/*div*/--> </div><!--/*div*/--> <div id="main"> <div id="link">click2</div><!--/*div*/--> <div id="box">content2</div><!--/*div*/--> </div><!--/*div*/--> <div id="main"> <div id="link">click3</div><!--/*div*/--> <div id="box">content3</div><!--/*div*/--> </div><!--/*div*/--> Jquery: <script type="text/javascript"> $(document).ready(function(){ $('#main #box').css('display', 'none') $('#main #link').click(function() { $(this).next('#main #box').slideToggle('slow') .siblings('#main #box:visible').css('display', 'none'); }); }); </script> Thanks!

    Read the article

  • How do i use SQL Server 2008? With Visual Studios?

    - by acidzombie24
    Its a two part question. How do i use SQL Server 2008? With Visual Studios? I started up a dummy project and with server explorer i tried with create new sql server database and add connection using my computer name (it came from a dropdown) as the server location. When i tried to create the database 'TestDB1' i got an error. I dont understand why. Its a fresh install and i have restarted the comp a few times since then. I havent messed with visual studios or the servers or even the control options to disable anything that would have been automatic. So whats with this? -edit- My goals are 1) create a database. 2) Be able to see all the database that exist on the server 3) execute sql queries in the ide 4) be able to browse tables. I dont need all of these but as many possible would be nice.

    Read the article

  • Good JDBC pattern

    - by Java Developer
    What is the good practice for database operation in Java application? Do you construct the DML syntax in the Java code and send the statements to DB engine for execution, or you just collect the parameters and then make a call to stored procedure with the parameters via java code? or neither because that's just not how to do it? can anyone give an example of a full database utility classes to do database operations in Java app? also what about the transaction manager? My assignment is to make database operation that is modular in Java. Thanks

    Read the article

  • How to find a between dates using sql?

    - by rajeeshmenoth
    How to reject without saving dates in database? Eg: the two columns in a database are from_date and to_date From date : 25/08/2014 To date : 29/08/2014 Problem: the above dates are saved in a two fields like from_date and to_date (room reservation booking), the next reservation details I don't want the date between 25/08/2014 to 29/08/2014. The between dates are not saved in database. Only the from date and to date are saving into the database. How to block between date using sql?

    Read the article

  • getting (this) at different function

    - by twen_ta
    I have couple of input fields with the class "link". All of them should start the jqueryUI dialog so this is why I bind the method to a class and not an single id. The difficulty is now that i can't use the (this) in line 12, because that gives me the identity of the dialog and not the input element. As I am an beginner I don't know how to pass a variable to this event with the element of the input field. What I want to archive is that the dialog should start from the input field and should write the result back to that input field. 1. // this is the click event for the input-field class called "link" 2. $('.link') 3. .button() 4. .click(function() { 5. $('#dialog-form').dialog('open'); 6. 7. }); 8. 9. //this is an excerpt from the opened dialog box and the write back to the input field 10. $("#dialog-form").dialog({ 11. if (bValid) { 12. $('.link').val('' + 14. name.val() + ''); 15. $(this).dialog('close'); 16. } 17. });

    Read the article

  • Storing and displaying unicode string (??????) using PHP and MySQL

    - by Anirudh Goel
    I have to store hindi text in a MySQL database, fetch it using a PHP script and display it on a webpage. I did the following: I created a database and set its encoding to UTF-8 and also the collation to utf8_bin. I added a varchar field in the table and set it to accept UTF-8 text in the charset property. Then I set about adding data to it. Here I had to copy data from an existing site. The hindi text looks like this: ????????:05:30 I directly copied this text into my database and used the PHP code echo(utf8_encode($string)) to display the data. Upon doing so the browser showed me "??????". When I inserted the UTF equivalent of the text by going to "view source" in the browser, however, ???????? translates into &#2360;&#2370;&#2352;&#2381;&#2351;&#2379;&#2342;&#2351;. If I enter and store &#2360;&#2370;&#2352;&#2381;&#2351;&#2379;&#2342;&#2351; in the database, it converts perfectly. So what I want to know is how I can directly store ???????? into my database and fetch it and display it in my webpage using PHP. Also, can anyone help me understand if there's a script which when I type in ????????, gives me &#2360;&#2370;&#2352;&#2381;&#2351;&#2379;&#2342;&#2351;? Solution Found I wrote the following sample script which worked for me. Hope it helps someone else too <html> <head> <title>Hindi</title></head> <body> <?php include("connection.php"); //simple connection setting $result = mysql_query("SET NAMES utf8"); //the main trick $cmd = "select * from hindi"; $result = mysql_query($cmd); while ($myrow = mysql_fetch_row($result)) { echo ($myrow[0]); } ?> </body> </html> The dump for my database storing hindi utf strings is CREATE TABLE `hindi` ( `data` varchar(1000) character set utf8 collate utf8_bin default NULL ) ENGINE=InnoDB DEFAULT CHARSET=latin1; INSERT INTO `hindi` VALUES ('????????'); Now my question is, how did it work without specifying "META" or header info? Thanks!

    Read the article

  • spaces or %20 in links turn into + signs when page is sent as an email

    - by Obay
    I am creating a web app that accepts input of news items (title, article, url). It has a page news.php which creates a summary of all news items inputted for specified dates, like so: News 4/25/2010 Title 1 [URL 1] Article 1 Title 2 [URL 2] Article 2 and so on... I have two other pages, namely preview.php and send.php , both of which call news.php through a file_get_contents() call. Everything works fine except when the URL contains spaces. During Preview, the urls get opened (FF: spaces are spaces, Chrome: spaces are %20). However, during Send, when received as emails, the urls don't get opened, because the spaces are converted into + signs. For example: 1. Preview in FF: http://www.example.com/this is the link.html 2. Preview in Chrome: http://www.example.com/this%20is%20the%20link.html 3. Viewed as email in both browsers: http://www.example.com/this+is+the+link.html Only #3 doesn't work (link doesn't get opened). Why are the spaces in the urls correct (spaces or %20) when previewed, but incorrect (+) when received in the emails, when in fact, the same page is generated by the same news.php? Any help appreciated :)

    Read the article

  • Our Look at Opera 10.50 Web Browser

    - by Asian Angel
    Everyone has been talking about the newest version of Opera recently but perhaps you have not looked at it too closely yet. Today we will take a look at 10.50 and let you see what this “new browser” is all about. The New Engines Carakan JavaScript Engine: Runs web applications up to 7 times faster than its predecessor Futhark Vega Graphics Library: Enables super fast and smooth graphics on everything from tab switching to webpage animation Presto 2.5: Provides support for HTML5, CSS2.1 and the latest CSS3 standards A Look at the Features Available If you have installed or used older versions of Opera before then the default look after a clean install will probably seem rather different. The main differences in appearance are mainly located within the “glass border” areas of the browser. The “Speed Dial” setup looks and works just as well as in previous versions. You can set a favorite wallpaper or image as your background and choose the number of “dials” using the “Configure Speed Dial Command”. One of the “standout” differences is the “O Button”. All of the menus have been condensed into this single access point but it only takes a few moments to find what you are looking for. If you have used the style before in earlier versions of Opera some of the items have been moved around. For those who prefer the “Menu Bar” that can be easily restored using the “Show Menu Bar Command”. If desired you can actually “extend” the “Tab Bar” downwards to display thumbnails of your open tabs. Just use your mouse to grab the bottom of the “Tab Bar” and adjust it to suit your personal needs. The only problem with this feature is that it will quickly use up a good sized portion of your available UI and browser window space. The “Password Manager” is ready to access when needed…the background for the button will turn a shiny metallic blue when you open a webpage that you have “Login Information” saved for. One of the new features is a small “Recycle Bin Button” in the upper right corner. Clicking on this will display a list of recently closed tabs letting you have easy access to any tabs that you may have accidentally closed. This is definitely a great feature to have as an easy access button. For those who were used to how the “Zoom Feature” looked before it has a new “look” to it. Instead of the pop-up menu-type listing of “view sizes” present before you now have a slider button that you can use to adjust the zooming level. For our default setup here the “Sidebar Panels” available were: “Bookmarks, Widgets, Unite, Notes, Downloads, History, & Panels”. Additional panels such as “Links, Windows, Search, Info, etc.” are available if you want and/or need them (accessible using the “Panels Plus Sign Button”). The “Opera Link Button” makes it easy for you to synchronize your “Speed Dial, Bookmarks, Personal Bar, Custom Searches, History & Notes”. Note: “Opera Link” requires an account and can be signed up for using the link provided below. Want to share files with your family and friends? “Unite” allows you to do that and more. With “Unite” you can: “Stream Music, Show Photo Galleries, Share Files and/or Folders, & host webpages directly from your browser”. We have a more in-depth look at “Unite” in our article here. Note: Use of “Unite” requires an Opera account. Got a slow internet connection? “Opera Turbo” can help with that by running the web traffic through their “compression servers” to speed up your web browsing. Keep in mind that “Opera Turbo” will not engage if you are accessing a secure website (i.e. your bank’s website) thus preserving your security. Note: “Opera Turbo” can be set up to automatically detect slow internet connections (i.e. crowded Wi-Fi in a cafe). Opera has a built-in “Private Browsing Mode” now for those who prefer anonymous browsing and want to keep the “history records clean” on their computer. To access it go to “Tabs and windows” and select “New private tab” or “New private window” as desired. When you open your new “Private Tab or Window” you will see the following message with details on how Opera will handle browsing information and a large “door hanger symbol”. Notice that the one tab is locked into “Private Browsing Mode” while the others are still working in “Regular Browsing Mode”. Very nice! A miniature version of the “door hanger symbol” will be present on any tab that is locked into “Private Browsing Mode”. If you are using Windows 7 then you will love how things look from your “Taskbar”. Here you can see four very nice looking thumbnails for the tabs that we had open. All that you have to do is click on the desired thumbnail… The “Context Menu” looks just as lovely as the thumbnails and definitely has some terrific functionality built into it. Add Enhanced Aero Capability If you love “Aero” and want more for your new Opera install then we have the perfect theme for you. The theme’s name is Z1-AV69 and once you have downloaded it you will need to place it in the “Skins Subfolder” in Opera’s “Program Files Folder”. Note: For our example we used version 1.10 but version 2.00 is now available (link provided below). Once you have restarted Opera, go to the “O Menu” and select “Appearance”. When the “Appearance Window” opens click on “Z1-Glass Skin” and then click “OK”. All of a sudden you will have more “Aero Goodness” to enjoy. Compare this screenshot with the one at the top of this article…the only part that is not transparent now is the browser window area itself. Want even more “Aero Goodness”? Right click on the “Tab Bar” and set “Tab Bar Placement” to “Left”. Note: You can achieve the same effect by setting the “Tab Bar Placement” to “Right”. With the “Speed Dial” visible you will be able to see your wallpaper with ease. While this is obviously not for everyone it does make for a great visual trick. Portable Versions Perhaps you need this wonderful new version of Opera to go with you wherever you do during the day. Not a problem…just visit the Opera USB website to choose a version that works best for you. You can select from “Zip or Exe” setup files and if needed update an older portable version using a “Zipped Update Files Package”. If you are updating an older version keep in mind that you will need to delete the old “OperaUSB.exe. File” due to changes with the new setup files. During our tests updating older portable versions went well for the most part but we did experience a few “odd UI quirks” here and there…so we recommend setting up a clean install if possible. Conclusion The new 10.50 release is a pleasure to use and is a recommended install for your system. Whether you are considering trying Opera for the first time or have been using it for a bit we think that you will pleased with everything that the 10.50 release has to offer. For those who would like to add User Scripts to Opera be certain to look at our how-to article here. Links Download Opera 10.50 for your location (Windows) Get the latest Snapshot versions for Linux & Mac Sign up for an Opera Link account View In-Depth detail on Opera 10.50’s features Download the Z1-AV69 Aero Theme Download Portable Opera 10.50 Similar Articles Productive Geek Tips Set the Speed Dial as the Opera Startup PageSet Up User Scripts in Opera BrowserScan Files for Viruses Before You Download With Dr.WebTurn Your Computer into a File, Music, and Web Server with Opera UniteSet the Default Browser on Ubuntu From the Command Line TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 PCmover Professional Make your Joomla & Drupal Sites Mobile with OSMOBI Integrate Twitter and Delicious and Make Life Easier Design Your Web Pages Using the Golden Ratio Worldwide Growth of the Internet How to Find Your Mac Address Use My TextTools to Edit and Organize Text

    Read the article

  • Issue 15: Oracle PartnerNetwork Exchange @ Oracle OpenWorld

    - by rituchhibber
         ORACLE FOCUS Oracle PartnerNetwork Exchange@ ORACLE OpenWorld Sylvie MichouSenior DirectorPartner Marketing & Communications and Strategic Programs RESOURCES -- Oracle OpenWorld 2012 Oracle PartnerNetwork Exchange @ OpenWorld Oracle PartnerNetwork Exchange @ OpenWorld Registration Oracle PartnerNetwork Exchange SpecializationTest Fest Oracle OpenWorld Schedule Builder Oracle OpenWorld Promotional Toolkit for Partners Oracle Partner Events Oracle Partner Webcasts Oracle EMEA Partner News SUBSCRIBE FEEDBACK PREVIOUS ISSUES If you are attending our forthcoming Oracle OpenWorld 2012 conference in San Francisco from 30 September to 4 October, you will discover a new dedicated programme of keynotes and sessions tailored especially for you, our valued partners. Oracle PartnerNetwork Exchange @ OpenWorld has been created to enhance the opportunities for you to learn from and network with Oracle executives and experts. The programme also provides more informal opportunities than ever throughout the week to meet up with the people who are most important to your business: customers, prospects, colleagues and the Oracle EMEA Alliances & Channels management team. Oracle remains fully focused on building the industry's most admired partner ecosystem—which today spans over 25,000 partners. This new OPN Exchange programme offers an exciting change of pace for partners throughout the conference. Now it will be possible to enjoy a fully-integrated, partner-dedicated session schedule throughout the week, as well as key social events such as the Sunday night Welcome Reception, networking lunches from Monday to Thursday at the Howard Street Tent, and a fantastic closing event on the last Thursday afternoon. In addition to the regular Oracle OpenWorld conference schedule, if you have registered for the Oracle PartnerNetwork Exchange @ OpenWorld programme, you will be invited to attend a much anticipated global partner keynote presentation, plus more than 40 conference sessions aimed squarely at what's most important to you, as partners. Prominent topics for discussion will include: Oracle technologies and roadmaps and how they fit with partners' business plans; business development; regional distinctions in business practices; and much more. Each session will provide plenty of food for thought ahead of the numerous networking opportunities throughout the week, encouraging the knowledge exchange with Oracle executives, customers, prospects, and colleagues that will make this conference of even greater value for you. At Oracle we always work closely with our partners to deliver solution offerings that improve business value, simplify the IT experience and drive innovation and efficiencies for joint customers. The most important element of our new OPN Exchange is content that helps you get more from technology investments, more from your peer-to-peer connections, and more from your interactions with customers. To this end we've created some partner-specific tools which can be used by OPN members ahead of the conference itself. Crucially, a comprehensive Content Catalog already lists and organises details of every OPN Exchange session, speaker, exhibitor, demonstration and related materials. This Content Catalog can be used by all our partners to identify interesting content that you can add to your own personalised Oracle OpenWorld Schedule Builder, allowing more effective planning and pre-enrolment for vital sessions. There are numerous highlights that you will definitely want to include in those personal schedules. On Sunday morning, 30 September we will start the week with partner dedicated OPN Exchange sessions, following our Global Partner Keynote at 13:00 with Judson Althoff, SVP, Worldwide Alliances & Channels and Embedded Sales and senior executives, giving insight into Oracle's partner vision, strategy, and resources—all designed to help build and strengthen market opportunities for you. This will be followed by a number of OPN Exchange general sessions, the Oracle OpenWorld Opening Keynote with Larry Ellison, CEO, Oracle and concluded with the OPN Exchange AfterDark Welcome Reception, starting at 19:30 at the Metreon. From Monday 1 to Thursday 4 October, you can attend the OPN Exchange sessions that are most relevant to your business today and over the coming year. Oracle's top product and sales leaders will be on hand to discuss Oracle's strategic direction in 40+ targeted and in-depth sessions focussing on critical success factors to develop your business. Oracle's dedication to innovation, specialization, enablement and engineering provides Oracle partners with a huge opportunity to create new services and solutions, differentiate themselves and deliver extreme value to joint customers across the globe. Oracle will even be helping over 1000 partners to earn OPN Specialization certification during the Oracle OpenWorld OPN Exchange Test Fest, which will be providing all the study materials and exams required to drive Specialization for free at the conference. You simply need to check the list of current certification tracks available, and make sure you pre-register to reserve a seat in one of the ten sessions being offered free to OPN Exchange registered attendees. And finally, let's not forget those all-important networking opportunities, which can so often provide partners with valuable long-term alliances as well as exciting new business leads. The Oracle PartnerNetwork Lounge, located at Moscone South, exhibition hall, room 100 is the place where partners can meet formally or informally with colleagues, customers, prospects, and other industry professionals. OPN Specialized partners with OPN Exchange passes can also visit the OPN Video Blogging room to record and share ideas, and at the OPN Information Station you will find consultants available to answer your questions. "For the first time ever we will have a full partner conference within OpenWorld. OPN Exchange @ OpenWorld will kick-off on the first Sunday and run the entire week. We'll have over 40 sessions throughout that time and partners will hear from our top development executives, with special sessions dedicated to partnering throughout. It's going to be a phenomenal event, and we look forward to seeing our partners there." Judson Althoff, SVP, Oracle Worldwide Alliances & Channels and Embedded Sales So if you haven't done so already, please register for Oracle PartnerNetwork Exchange @ OpenWorld today or add OPN Exchange to your existing registration for just $100 through My Account. And if you have any further questions regarding partner activities at Oracle OpenWorld, please don't hesitate to contact the Oracle PartnerNetwork team at [email protected] will be on hand to share the very latest information about: Oracle's SPARC Superclusters: the latest Engineered Systems from Oracle, delivering radically improved performance, faster deployment and greatly reduced operational costs for mixed database and enterprise application consolidation Oracle's SPARC T4 servers: with the newly developed T4 processor and Oracle Solaris providing up to five times the single threaded performance and better overall system throughput for expanded application versatility Oracle Database Appliance: a new way to take advantage of the world's most popular database, Oracle Database 11g, in a single, easy-to-deploy and manage system. It's a complete package engineered to deliver simple, reliable and affordable database services to small and medium size businesses and departmental systems. All hardware and software components are supported together and offer customers unique pay-as-you-grow software licensing to quickly scale from two to 24 processor cores without incurring the costs and downtime usually associated with hardware upgrades Oracle Exalogic: the world's only integrated cloud machine, featuring server hardware and middleware software engineered together for maximum performance with minimum set-up and operational cost Oracle Exadata Database Machine: the only database machine that provides extreme performance for both data warehousing and online transaction processing (OLTP) applications, making it the ideal platform for consolidating onto grids or private clouds. It is a complete package of servers, storage, networking and software that is massively scalable, secure and redundant Oracle Sun ZFS Storage Appliances: providing enterprise-class NAS performance, price-performance, manageability and TCO by combining third-generation software with high-performance controllers, flash-based caches and disks Oracle Pillar Axiom Quality-of-Service: confidently consolidate storage for multiple applications into a single datacentre storage solution Oracle Solaris 11: delivering secure enterprise cloud deployments with the ability to run hundreds of virtual application with no overhead and co-engineered with other Oracle software products to provide the highest levels of security, manageability and performance Oracle Enterprise Manager 12c: Oracle's integrated enterprise IT management product, providing the industry's only complete, integrated and business-driven enterprise cloud management solution Oracle VM 3.0: the latest release of Oracle's server virtualisation and management solution, helping to move datacentres beyond server consolidation to improve application deployment and management. Register today and ensure your place at the Extreme Performance Tour! Extreme Performance Tour events are free to attend, but places are limited. To make sure that you don't miss out, please visit Oracle's Extreme Performance Tour website, select the city that you'd be interest in attending an event in, and then click on the 'Register Now' button for that city to secure your interest. Each individual city page also contains more in-depth information about your local event, including logistics, agenda and maybe even a preview of VIP guest speakers. -- Oracle OpenWorld 2010 Whether you attended Oracle OpenWorld 2009 or not, don't forget to save the date now for Oracle OpenWorld 2010. The event will be held a little earlier next year, from 19th-23rd September, so please don't miss out. With thousands of sessions and hundreds of exhibits and demos already lined up, there's no better place to learn how to optimise your existing systems, get an inside line on upcoming technology breakthroughs, and meet with your partner peers, Oracle strategists and even the developers responsible for the products and services that help you get better results for your end customers. Register Now for Oracle OpenWorld 2010! Perhaps you are interested in learning more about Oracle OpenWorld 2010, but don't wish to register at this time? Great! Please just enter your contact information here and we will contact you at a later date. How to Exhibit at Oracle OpenWorld 2010 Sponsorship Opportunities at Oracle OpenWorld 2010 Advertising Opportunities at Oracle OpenWorld 2010 -- Back to the welcome page

    Read the article

  • Introduction to the ASP.NET Web API

    - by Stephen.Walther
    I am a huge fan of Ajax. If you want to create a great experience for the users of your website – regardless of whether you are building an ASP.NET MVC or an ASP.NET Web Forms site — then you need to use Ajax. Otherwise, you are just being cruel to your customers. We use Ajax extensively in several of the ASP.NET applications that my company, Superexpert.com, builds. We expose data from the server as JSON and use jQuery to retrieve and update that data from the browser. One challenge, when building an ASP.NET website, is deciding on which technology to use to expose JSON data from the server. For example, how do you expose a list of products from the server as JSON so you can retrieve the list of products with jQuery? You have a number of options (too many options) including ASMX Web services, WCF Web Services, ASHX Generic Handlers, WCF Data Services, and MVC controller actions. Fortunately, the world has just been simplified. With the release of ASP.NET 4 Beta, Microsoft has introduced a new technology for exposing JSON from the server named the ASP.NET Web API. You can use the ASP.NET Web API with both ASP.NET MVC and ASP.NET Web Forms applications. The goal of this blog post is to provide you with a brief overview of the features of the new ASP.NET Web API. You learn how to use the ASP.NET Web API to retrieve, insert, update, and delete database records with jQuery. We also discuss how you can perform form validation when using the Web API and use OData when using the Web API. Creating an ASP.NET Web API Controller The ASP.NET Web API exposes JSON data through a new type of controller called an API controller. You can add an API controller to an existing ASP.NET MVC 4 project through the standard Add Controller dialog box. Right-click your Controllers folder and select Add, Controller. In the dialog box, name your controller MovieController and select the Empty API controller template: A brand new API controller looks like this: using System; using System.Collections.Generic; using System.Linq; using System.Net.Http; using System.Web.Http; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { } } An API controller, unlike a standard MVC controller, derives from the base ApiController class instead of the base Controller class. Using jQuery to Retrieve, Insert, Update, and Delete Data Let’s create an Ajaxified Movie Database application. We’ll retrieve, insert, update, and delete movies using jQuery with the MovieController which we just created. Our Movie model class looks like this: namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } public string Title { get; set; } public string Director { get; set; } } } Our application will consist of a single HTML page named Movies.html. We’ll place all of our jQuery code in the Movies.html page. Getting a Single Record with the ASP.NET Web API To support retrieving a single movie from the server, we need to add a Get method to our API controller: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public Movie GetMovie(int id) { // Return movie by id if (id == 1) { return new Movie { Id = 1, Title = "Star Wars", Director = "Lucas" }; } // Otherwise, movie was not found throw new HttpResponseException(HttpStatusCode.NotFound); } } } In the code above, the GetMovie() method accepts the Id of a movie. If the Id has the value 1 then the method returns the movie Star Wars. Otherwise, the method throws an exception and returns 404 Not Found HTTP status code. After building your project, you can invoke the MovieController.GetMovie() method by entering the following URL in your web browser address bar: http://localhost:[port]/api/movie/1 (You’ll need to enter the correct randomly generated port). In the URL api/movie/1, the first “api” segment indicates that this is a Web API route. The “movie” segment indicates that the MovieController should be invoked. You do not specify the name of the action. Instead, the HTTP method used to make the request – GET, POST, PUT, DELETE — is used to identify the action to invoke. The ASP.NET Web API uses different routing conventions than normal ASP.NET MVC controllers. When you make an HTTP GET request then any API controller method with a name that starts with “GET” is invoked. So, we could have called our API controller action GetPopcorn() instead of GetMovie() and it would still be invoked by the URL api/movie/1. The default route for the Web API is defined in the Global.asax file and it looks like this: routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); We can invoke our GetMovie() controller action with the jQuery code in the following HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Get Movie</title> </head> <body> <div> Title: <span id="title"></span> </div> <div> Director: <span id="director"></span> </div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> getMovie(1, function (movie) { $("#title").html(movie.Title); $("#director").html(movie.Director); }); function getMovie(id, callback) { $.ajax({ url: "/api/Movie", data: { id: id }, type: "GET", contentType: "application/json;charset=utf-8", statusCode: { 200: function (movie) { callback(movie); }, 404: function () { alert("Not Found!"); } } }); } </script> </body> </html> In the code above, the jQuery $.ajax() method is used to invoke the GetMovie() method. Notice that the Ajax call handles two HTTP response codes. When the GetMove() method successfully returns a movie, the method returns a 200 status code. In that case, the details of the movie are displayed in the HTML page. Otherwise, if the movie is not found, the GetMovie() method returns a 404 status code. In that case, the page simply displays an alert box indicating that the movie was not found (hopefully, you would implement something more graceful in an actual application). You can use your browser’s Developer Tools to see what is going on in the background when you open the HTML page (hit F12 in the most recent version of most browsers). For example, you can use the Network tab in Google Chrome to see the Ajax request which invokes the GetMovie() method: Getting a Set of Records with the ASP.NET Web API Let’s modify our Movie API controller so that it returns a collection of movies. The following Movie controller has a new ListMovies() method which returns a (hard-coded) collection of movies: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public IEnumerable<Movie> ListMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=1, Title="King Kong", Director="Jackson"}, new Movie {Id=1, Title="Memento", Director="Nolan"} }; } } } Because we named our action ListMovies(), the default Web API route will never match it. Therefore, we need to add the following custom route to our Global.asax file (at the top of the RegisterRoutes() method): routes.MapHttpRoute( name: "ActionApi", routeTemplate: "api/{controller}/{action}/{id}", defaults: new { id = RouteParameter.Optional } ); This route enables us to invoke the ListMovies() method with the URL /api/movie/listmovies. Now that we have exposed our collection of movies from the server, we can retrieve and display the list of movies using jQuery in our HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>List Movies</title> </head> <body> <div id="movies"></div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> listMovies(function (movies) { var strMovies=""; $.each(movies, function (index, movie) { strMovies += "<div>" + movie.Title + "</div>"; }); $("#movies").html(strMovies); }); function listMovies(callback) { $.ajax({ url: "/api/Movie/ListMovies", data: {}, type: "GET", contentType: "application/json;charset=utf-8", }).then(function(movies){ callback(movies); }); } </script> </body> </html>     Inserting a Record with the ASP.NET Web API Now let’s modify our Movie API controller so it supports creating new records: public HttpResponseMessage<Movie> PostMovie(Movie movieToCreate) { // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } The PostMovie() method in the code above accepts a movieToCreate parameter. We don’t actually store the new movie anywhere. In real life, you will want to call a service method to store the new movie in a database. When you create a new resource, such as a new movie, you should return the location of the new resource. In the code above, the URL where the new movie can be retrieved is assigned to the Location header returned in the PostMovie() response. Because the name of our method starts with “Post”, we don’t need to create a custom route. The PostMovie() method can be invoked with the URL /Movie/PostMovie – just as long as the method is invoked within the context of a HTTP POST request. The following HTML page invokes the PostMovie() method. <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "Jackson" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }); function createMovie(movieToCreate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); } </script> </body> </html> This page creates a new movie (the Hobbit) by calling the createMovie() method. The page simply displays the Id of the new movie: The HTTP Post operation is performed with the following call to the jQuery $.ajax() method: $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); Notice that the type of Ajax request is a POST request. This is required to match the PostMovie() method. Notice, furthermore, that the new movie is converted into JSON using JSON.stringify(). The JSON.stringify() method takes a JavaScript object and converts it into a JSON string. Finally, notice that success is represented with a 201 status code. The HttpStatusCode.Created value returned from the PostMovie() method returns a 201 status code. Updating a Record with the ASP.NET Web API Here’s how we can modify the Movie API controller to support updating an existing record. In this case, we need to create a PUT method to handle an HTTP PUT request: public void PutMovie(Movie movieToUpdate) { if (movieToUpdate.Id == 1) { // Update the movie in the database return; } // If you can't find the movie to update throw new HttpResponseException(HttpStatusCode.NotFound); } Unlike our PostMovie() method, the PutMovie() method does not return a result. The action either updates the database or, if the movie cannot be found, returns an HTTP Status code of 404. The following HTML page illustrates how you can invoke the PutMovie() method: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Put Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToUpdate = { id: 1, title: "The Hobbit", director: "Jackson" }; updateMovie(movieToUpdate, function () { alert("Movie updated!"); }); function updateMovie(movieToUpdate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToUpdate), type: "PUT", contentType: "application/json;charset=utf-8", statusCode: { 200: function () { callback(); }, 404: function () { alert("Movie not found!"); } } }); } </script> </body> </html> Deleting a Record with the ASP.NET Web API Here’s the code for deleting a movie: public HttpResponseMessage DeleteMovie(int id) { // Delete the movie from the database // Return status code return new HttpResponseMessage(HttpStatusCode.NoContent); } This method simply deletes the movie (well, not really, but pretend that it does) and returns a No Content status code (204). The following page illustrates how you can invoke the DeleteMovie() action: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Delete Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> deleteMovie(1, function () { alert("Movie deleted!"); }); function deleteMovie(id, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify({id:id}), type: "DELETE", contentType: "application/json;charset=utf-8", statusCode: { 204: function () { callback(); } } }); } </script> </body> </html> Performing Validation How do you perform form validation when using the ASP.NET Web API? Because validation in ASP.NET MVC is driven by the Default Model Binder, and because the Web API uses the Default Model Binder, you get validation for free. Let’s modify our Movie class so it includes some of the standard validation attributes: using System.ComponentModel.DataAnnotations; namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } [Required(ErrorMessage="Title is required!")] [StringLength(5, ErrorMessage="Title cannot be more than 5 characters!")] public string Title { get; set; } [Required(ErrorMessage="Director is required!")] public string Director { get; set; } } } In the code above, the Required validation attribute is used to make both the Title and Director properties required. The StringLength attribute is used to require the length of the movie title to be no more than 5 characters. Now let’s modify our PostMovie() action to validate a movie before adding the movie to the database: public HttpResponseMessage PostMovie(Movie movieToCreate) { // Validate movie if (!ModelState.IsValid) { var errors = new JsonArray(); foreach (var prop in ModelState.Values) { if (prop.Errors.Any()) { errors.Add(prop.Errors.First().ErrorMessage); } } return new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } If ModelState.IsValid has the value false then the errors in model state are copied to a new JSON array. Each property – such as the Title and Director property — can have multiple errors. In the code above, only the first error message is copied over. The JSON array is returned with a Bad Request status code (400 status code). The following HTML page illustrates how you can invoke our modified PostMovie() action and display any error messages: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }, function (errors) { var strErrors = ""; $.each(errors, function(index, err) { strErrors += "*" + err + "\n"; }); alert(strErrors); } ); function createMovie(movieToCreate, success, fail) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToCreate), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { success(newMovie); }, 400: function (xhr) { var errors = JSON.parse(xhr.responseText); fail(errors); } } }); } </script> </body> </html> The createMovie() function performs an Ajax request and handles either a 201 or a 400 status code from the response. If a 201 status code is returned then there were no validation errors and the new movie was created. If, on the other hand, a 400 status code is returned then there was a validation error. The validation errors are retrieved from the XmlHttpRequest responseText property. The error messages are displayed in an alert: (Please don’t use JavaScript alert dialogs to display validation errors, I just did it this way out of pure laziness) This validation code in our PostMovie() method is pretty generic. There is nothing specific about this code to the PostMovie() method. In the following video, Jon Galloway demonstrates how to create a global Validation filter which can be used with any API controller action: http://www.asp.net/web-api/overview/web-api-routing-and-actions/video-custom-validation His validation filter looks like this: using System.Json; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http.Controllers; using System.Web.Http.Filters; namespace MyWebAPIApp.Filters { public class ValidationActionFilter:ActionFilterAttribute { public override void OnActionExecuting(HttpActionContext actionContext) { var modelState = actionContext.ModelState; if (!modelState.IsValid) { dynamic errors = new JsonObject(); foreach (var key in modelState.Keys) { var state = modelState[key]; if (state.Errors.Any()) { errors[key] = state.Errors.First().ErrorMessage; } } actionContext.Response = new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } } } } And you can register the validation filter in the Application_Start() method in the Global.asax file like this: GlobalConfiguration.Configuration.Filters.Add(new ValidationActionFilter()); After you register the Validation filter, validation error messages are returned from any API controller action method automatically when validation fails. You don’t need to add any special logic to any of your API controller actions to take advantage of the filter. Querying using OData The OData protocol is an open protocol created by Microsoft which enables you to perform queries over the web. The official website for OData is located here: http://odata.org For example, here are some of the query options which you can use with OData: · $orderby – Enables you to retrieve results in a certain order. · $top – Enables you to retrieve a certain number of results. · $skip – Enables you to skip over a certain number of results (use with $top for paging). · $filter – Enables you to filter the results returned. The ASP.NET Web API supports a subset of the OData protocol. You can use all of the query options listed above when interacting with an API controller. The only requirement is that the API controller action returns its data as IQueryable. For example, the following Movie controller has an action named GetMovies() which returns an IQueryable of movies: public IQueryable<Movie> GetMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=2, Title="King Kong", Director="Jackson"}, new Movie {Id=3, Title="Willow", Director="Lucas"}, new Movie {Id=4, Title="Shrek", Director="Smith"}, new Movie {Id=5, Title="Memento", Director="Nolan"} }.AsQueryable(); } If you enter the following URL in your browser: /api/movie?$top=2&$orderby=Title Then you will limit the movies returned to the top 2 in order of the movie Title. You will get the following results: By using the $top option in combination with the $skip option, you can enable client-side paging. For example, you can use $top and $skip to page through thousands of products, 10 products at a time. The $filter query option is very powerful. You can use this option to filter the results from a query. Here are some examples: Return every movie directed by Lucas: /api/movie?$filter=Director eq ‘Lucas’ Return every movie which has a title which starts with ‘S’: /api/movie?$filter=startswith(Title,’S') Return every movie which has an Id greater than 2: /api/movie?$filter=Id gt 2 The complete documentation for the $filter option is located here: http://www.odata.org/developers/protocols/uri-conventions#FilterSystemQueryOption Summary The goal of this blog entry was to provide you with an overview of the new ASP.NET Web API introduced with the Beta release of ASP.NET 4. In this post, I discussed how you can retrieve, insert, update, and delete data by using jQuery with the Web API. I also discussed how you can use the standard validation attributes with the Web API. You learned how to return validation error messages to the client and display the error messages using jQuery. Finally, we briefly discussed how the ASP.NET Web API supports the OData protocol. For example, you learned how to filter records returned from an API controller action by using the $filter query option. I’m excited about the new Web API. This is a feature which I expect to use with almost every ASP.NET application which I build in the future.

    Read the article

  • Introduction to the ASP.NET Web API

    - by Stephen.Walther
    I am a huge fan of Ajax. If you want to create a great experience for the users of your website – regardless of whether you are building an ASP.NET MVC or an ASP.NET Web Forms site — then you need to use Ajax. Otherwise, you are just being cruel to your customers. We use Ajax extensively in several of the ASP.NET applications that my company, Superexpert.com, builds. We expose data from the server as JSON and use jQuery to retrieve and update that data from the browser. One challenge, when building an ASP.NET website, is deciding on which technology to use to expose JSON data from the server. For example, how do you expose a list of products from the server as JSON so you can retrieve the list of products with jQuery? You have a number of options (too many options) including ASMX Web services, WCF Web Services, ASHX Generic Handlers, WCF Data Services, and MVC controller actions. Fortunately, the world has just been simplified. With the release of ASP.NET 4 Beta, Microsoft has introduced a new technology for exposing JSON from the server named the ASP.NET Web API. You can use the ASP.NET Web API with both ASP.NET MVC and ASP.NET Web Forms applications. The goal of this blog post is to provide you with a brief overview of the features of the new ASP.NET Web API. You learn how to use the ASP.NET Web API to retrieve, insert, update, and delete database records with jQuery. We also discuss how you can perform form validation when using the Web API and use OData when using the Web API. Creating an ASP.NET Web API Controller The ASP.NET Web API exposes JSON data through a new type of controller called an API controller. You can add an API controller to an existing ASP.NET MVC 4 project through the standard Add Controller dialog box. Right-click your Controllers folder and select Add, Controller. In the dialog box, name your controller MovieController and select the Empty API controller template: A brand new API controller looks like this: using System; using System.Collections.Generic; using System.Linq; using System.Net.Http; using System.Web.Http; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { } } An API controller, unlike a standard MVC controller, derives from the base ApiController class instead of the base Controller class. Using jQuery to Retrieve, Insert, Update, and Delete Data Let’s create an Ajaxified Movie Database application. We’ll retrieve, insert, update, and delete movies using jQuery with the MovieController which we just created. Our Movie model class looks like this: namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } public string Title { get; set; } public string Director { get; set; } } } Our application will consist of a single HTML page named Movies.html. We’ll place all of our jQuery code in the Movies.html page. Getting a Single Record with the ASP.NET Web API To support retrieving a single movie from the server, we need to add a Get method to our API controller: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public Movie GetMovie(int id) { // Return movie by id if (id == 1) { return new Movie { Id = 1, Title = "Star Wars", Director = "Lucas" }; } // Otherwise, movie was not found throw new HttpResponseException(HttpStatusCode.NotFound); } } } In the code above, the GetMovie() method accepts the Id of a movie. If the Id has the value 1 then the method returns the movie Star Wars. Otherwise, the method throws an exception and returns 404 Not Found HTTP status code. After building your project, you can invoke the MovieController.GetMovie() method by entering the following URL in your web browser address bar: http://localhost:[port]/api/movie/1 (You’ll need to enter the correct randomly generated port). In the URL api/movie/1, the first “api” segment indicates that this is a Web API route. The “movie” segment indicates that the MovieController should be invoked. You do not specify the name of the action. Instead, the HTTP method used to make the request – GET, POST, PUT, DELETE — is used to identify the action to invoke. The ASP.NET Web API uses different routing conventions than normal ASP.NET MVC controllers. When you make an HTTP GET request then any API controller method with a name that starts with “GET” is invoked. So, we could have called our API controller action GetPopcorn() instead of GetMovie() and it would still be invoked by the URL api/movie/1. The default route for the Web API is defined in the Global.asax file and it looks like this: routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); We can invoke our GetMovie() controller action with the jQuery code in the following HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Get Movie</title> </head> <body> <div> Title: <span id="title"></span> </div> <div> Director: <span id="director"></span> </div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> getMovie(1, function (movie) { $("#title").html(movie.Title); $("#director").html(movie.Director); }); function getMovie(id, callback) { $.ajax({ url: "/api/Movie", data: { id: id }, type: "GET", contentType: "application/json;charset=utf-8", statusCode: { 200: function (movie) { callback(movie); }, 404: function () { alert("Not Found!"); } } }); } </script> </body> </html> In the code above, the jQuery $.ajax() method is used to invoke the GetMovie() method. Notice that the Ajax call handles two HTTP response codes. When the GetMove() method successfully returns a movie, the method returns a 200 status code. In that case, the details of the movie are displayed in the HTML page. Otherwise, if the movie is not found, the GetMovie() method returns a 404 status code. In that case, the page simply displays an alert box indicating that the movie was not found (hopefully, you would implement something more graceful in an actual application). You can use your browser’s Developer Tools to see what is going on in the background when you open the HTML page (hit F12 in the most recent version of most browsers). For example, you can use the Network tab in Google Chrome to see the Ajax request which invokes the GetMovie() method: Getting a Set of Records with the ASP.NET Web API Let’s modify our Movie API controller so that it returns a collection of movies. The following Movie controller has a new ListMovies() method which returns a (hard-coded) collection of movies: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public IEnumerable<Movie> ListMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=1, Title="King Kong", Director="Jackson"}, new Movie {Id=1, Title="Memento", Director="Nolan"} }; } } } Because we named our action ListMovies(), the default Web API route will never match it. Therefore, we need to add the following custom route to our Global.asax file (at the top of the RegisterRoutes() method): routes.MapHttpRoute( name: "ActionApi", routeTemplate: "api/{controller}/{action}/{id}", defaults: new { id = RouteParameter.Optional } ); This route enables us to invoke the ListMovies() method with the URL /api/movie/listmovies. Now that we have exposed our collection of movies from the server, we can retrieve and display the list of movies using jQuery in our HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>List Movies</title> </head> <body> <div id="movies"></div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> listMovies(function (movies) { var strMovies=""; $.each(movies, function (index, movie) { strMovies += "<div>" + movie.Title + "</div>"; }); $("#movies").html(strMovies); }); function listMovies(callback) { $.ajax({ url: "/api/Movie/ListMovies", data: {}, type: "GET", contentType: "application/json;charset=utf-8", }).then(function(movies){ callback(movies); }); } </script> </body> </html>     Inserting a Record with the ASP.NET Web API Now let’s modify our Movie API controller so it supports creating new records: public HttpResponseMessage<Movie> PostMovie(Movie movieToCreate) { // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } The PostMovie() method in the code above accepts a movieToCreate parameter. We don’t actually store the new movie anywhere. In real life, you will want to call a service method to store the new movie in a database. When you create a new resource, such as a new movie, you should return the location of the new resource. In the code above, the URL where the new movie can be retrieved is assigned to the Location header returned in the PostMovie() response. Because the name of our method starts with “Post”, we don’t need to create a custom route. The PostMovie() method can be invoked with the URL /Movie/PostMovie – just as long as the method is invoked within the context of a HTTP POST request. The following HTML page invokes the PostMovie() method. <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "Jackson" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }); function createMovie(movieToCreate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); } </script> </body> </html> This page creates a new movie (the Hobbit) by calling the createMovie() method. The page simply displays the Id of the new movie: The HTTP Post operation is performed with the following call to the jQuery $.ajax() method: $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); Notice that the type of Ajax request is a POST request. This is required to match the PostMovie() method. Notice, furthermore, that the new movie is converted into JSON using JSON.stringify(). The JSON.stringify() method takes a JavaScript object and converts it into a JSON string. Finally, notice that success is represented with a 201 status code. The HttpStatusCode.Created value returned from the PostMovie() method returns a 201 status code. Updating a Record with the ASP.NET Web API Here’s how we can modify the Movie API controller to support updating an existing record. In this case, we need to create a PUT method to handle an HTTP PUT request: public void PutMovie(Movie movieToUpdate) { if (movieToUpdate.Id == 1) { // Update the movie in the database return; } // If you can't find the movie to update throw new HttpResponseException(HttpStatusCode.NotFound); } Unlike our PostMovie() method, the PutMovie() method does not return a result. The action either updates the database or, if the movie cannot be found, returns an HTTP Status code of 404. The following HTML page illustrates how you can invoke the PutMovie() method: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Put Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToUpdate = { id: 1, title: "The Hobbit", director: "Jackson" }; updateMovie(movieToUpdate, function () { alert("Movie updated!"); }); function updateMovie(movieToUpdate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToUpdate), type: "PUT", contentType: "application/json;charset=utf-8", statusCode: { 200: function () { callback(); }, 404: function () { alert("Movie not found!"); } } }); } </script> </body> </html> Deleting a Record with the ASP.NET Web API Here’s the code for deleting a movie: public HttpResponseMessage DeleteMovie(int id) { // Delete the movie from the database // Return status code return new HttpResponseMessage(HttpStatusCode.NoContent); } This method simply deletes the movie (well, not really, but pretend that it does) and returns a No Content status code (204). The following page illustrates how you can invoke the DeleteMovie() action: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Delete Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> deleteMovie(1, function () { alert("Movie deleted!"); }); function deleteMovie(id, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify({id:id}), type: "DELETE", contentType: "application/json;charset=utf-8", statusCode: { 204: function () { callback(); } } }); } </script> </body> </html> Performing Validation How do you perform form validation when using the ASP.NET Web API? Because validation in ASP.NET MVC is driven by the Default Model Binder, and because the Web API uses the Default Model Binder, you get validation for free. Let’s modify our Movie class so it includes some of the standard validation attributes: using System.ComponentModel.DataAnnotations; namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } [Required(ErrorMessage="Title is required!")] [StringLength(5, ErrorMessage="Title cannot be more than 5 characters!")] public string Title { get; set; } [Required(ErrorMessage="Director is required!")] public string Director { get; set; } } } In the code above, the Required validation attribute is used to make both the Title and Director properties required. The StringLength attribute is used to require the length of the movie title to be no more than 5 characters. Now let’s modify our PostMovie() action to validate a movie before adding the movie to the database: public HttpResponseMessage PostMovie(Movie movieToCreate) { // Validate movie if (!ModelState.IsValid) { var errors = new JsonArray(); foreach (var prop in ModelState.Values) { if (prop.Errors.Any()) { errors.Add(prop.Errors.First().ErrorMessage); } } return new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } If ModelState.IsValid has the value false then the errors in model state are copied to a new JSON array. Each property – such as the Title and Director property — can have multiple errors. In the code above, only the first error message is copied over. The JSON array is returned with a Bad Request status code (400 status code). The following HTML page illustrates how you can invoke our modified PostMovie() action and display any error messages: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }, function (errors) { var strErrors = ""; $.each(errors, function(index, err) { strErrors += "*" + err + "n"; }); alert(strErrors); } ); function createMovie(movieToCreate, success, fail) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToCreate), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { success(newMovie); }, 400: function (xhr) { var errors = JSON.parse(xhr.responseText); fail(errors); } } }); } </script> </body> </html> The createMovie() function performs an Ajax request and handles either a 201 or a 400 status code from the response. If a 201 status code is returned then there were no validation errors and the new movie was created. If, on the other hand, a 400 status code is returned then there was a validation error. The validation errors are retrieved from the XmlHttpRequest responseText property. The error messages are displayed in an alert: (Please don’t use JavaScript alert dialogs to display validation errors, I just did it this way out of pure laziness) This validation code in our PostMovie() method is pretty generic. There is nothing specific about this code to the PostMovie() method. In the following video, Jon Galloway demonstrates how to create a global Validation filter which can be used with any API controller action: http://www.asp.net/web-api/overview/web-api-routing-and-actions/video-custom-validation His validation filter looks like this: using System.Json; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http.Controllers; using System.Web.Http.Filters; namespace MyWebAPIApp.Filters { public class ValidationActionFilter:ActionFilterAttribute { public override void OnActionExecuting(HttpActionContext actionContext) { var modelState = actionContext.ModelState; if (!modelState.IsValid) { dynamic errors = new JsonObject(); foreach (var key in modelState.Keys) { var state = modelState[key]; if (state.Errors.Any()) { errors[key] = state.Errors.First().ErrorMessage; } } actionContext.Response = new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } } } } And you can register the validation filter in the Application_Start() method in the Global.asax file like this: GlobalConfiguration.Configuration.Filters.Add(new ValidationActionFilter()); After you register the Validation filter, validation error messages are returned from any API controller action method automatically when validation fails. You don’t need to add any special logic to any of your API controller actions to take advantage of the filter. Querying using OData The OData protocol is an open protocol created by Microsoft which enables you to perform queries over the web. The official website for OData is located here: http://odata.org For example, here are some of the query options which you can use with OData: · $orderby – Enables you to retrieve results in a certain order. · $top – Enables you to retrieve a certain number of results. · $skip – Enables you to skip over a certain number of results (use with $top for paging). · $filter – Enables you to filter the results returned. The ASP.NET Web API supports a subset of the OData protocol. You can use all of the query options listed above when interacting with an API controller. The only requirement is that the API controller action returns its data as IQueryable. For example, the following Movie controller has an action named GetMovies() which returns an IQueryable of movies: public IQueryable<Movie> GetMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=2, Title="King Kong", Director="Jackson"}, new Movie {Id=3, Title="Willow", Director="Lucas"}, new Movie {Id=4, Title="Shrek", Director="Smith"}, new Movie {Id=5, Title="Memento", Director="Nolan"} }.AsQueryable(); } If you enter the following URL in your browser: /api/movie?$top=2&$orderby=Title Then you will limit the movies returned to the top 2 in order of the movie Title. You will get the following results: By using the $top option in combination with the $skip option, you can enable client-side paging. For example, you can use $top and $skip to page through thousands of products, 10 products at a time. The $filter query option is very powerful. You can use this option to filter the results from a query. Here are some examples: Return every movie directed by Lucas: /api/movie?$filter=Director eq ‘Lucas’ Return every movie which has a title which starts with ‘S’: /api/movie?$filter=startswith(Title,’S') Return every movie which has an Id greater than 2: /api/movie?$filter=Id gt 2 The complete documentation for the $filter option is located here: http://www.odata.org/developers/protocols/uri-conventions#FilterSystemQueryOption Summary The goal of this blog entry was to provide you with an overview of the new ASP.NET Web API introduced with the Beta release of ASP.NET 4. In this post, I discussed how you can retrieve, insert, update, and delete data by using jQuery with the Web API. I also discussed how you can use the standard validation attributes with the Web API. You learned how to return validation error messages to the client and display the error messages using jQuery. Finally, we briefly discussed how the ASP.NET Web API supports the OData protocol. For example, you learned how to filter records returned from an API controller action by using the $filter query option. I’m excited about the new Web API. This is a feature which I expect to use with almost every ASP.NET application which I build in the future.

    Read the article

  • Solaris 10 branded zone VM Templates for Solaris 11 on OTN

    - by jsavit
    Early this year I wrote the article Ours Goes To 11 which describes the ability to import Solaris 10 systems into a "Solaris 10 branded zone" under Oracle Solaris 11. I did this using Solaris 11 Express, and the capability remains in Solaris 11 with only slight changes. This important tool lets you painlessly inhaling a Solaris Container from Solaris 10 or entire Solaris 10 systems ("the global zone") into virtualized environments on a Solaris 11 OS. Just recently, Oracle provided Oracle VM Templates for Oracle Solaris 10 Zones to let you create Solaris 10 branded zones for Solaris 11 even if you don't currently have access to install media or a running Solaris 10 system. To use this, just download the Oracle VM Template for Oracle Solaris Zone 10 from OTN at http://www.oracle.com/technetwork/server-storage/solaris11/downloads/virtual-machines-1355605.html. This page contains images of Oracle Solaris 10 8/11 (the recent update to Solaris 10) in SPARC and x86 formats suitable for creating branded zones. The same page also has a VirtualBox image you can download for a complete Solaris 10 install in a guest virtual machine you can run on any host OS that supports VirtualBox. Both sets of downloads provide a quick - and extremely easy - way to set up a virtual Solaris 10 environment. In the case of the Oracle VM Templates, they illustrate several advanced features of Solaris 11. To start, just go to the above link, download the template for the hardware platform (SPARC or x86) you want, and download the README file also linked from that page. Install prerequisites The README file tells you to install the prerequisite Solaris 11 package that implements the Solaris 10 brand. Then you can install instances of zones with that brand. # pkg install pkg:/system/zones/brand/brand-solaris10 Packages to install: 1 Create boot environment: No Create backup boot environment: Yes DOWNLOAD PKGS FILES XFER (MB) Completed 1/1 44/44 0.4/0.4 PHASE ACTIONS Install Phase 74/74 PHASE ITEMS Package State Update Phase 1/1 Image State Update Phase 2/2 That took only a few minutes, and didn't require a reboot. Install the Solaris 10 zone Now it's time to run the downloaded template file. First make it executable via the chmod command, of course. I found that (unlike stated in the README) there was no need to rename the downloaded file to remove the .bin. When you run it you provide several parameters to describe the zone configuration: -a IP address - the IP address and optional netmask for the zone. This is the only mandatory parameter. -z zonename - the name of the zone you would like to create. -i interface - the package will create an exclusive-IP zone using a virtual NIC (vnic) based on this physical interface. In my case, I have a NIC called rge0. -p PATH - specifies the path in which you want the zoneroot to be placed. In my case, I have a ZFS dataset mounted at /zones, and this will create a zoneroot at /zones/s10u10. Kicking it off, you will see a copyright message, and then messages showing progress building the zone, which only takes a few minutes. # ./solaris-10u10-x86.bin -p /zones -a 192.168.1.100 -i rge0 -z s10u10 ... ... Checking disk-space for extraction Ok Extracting in /export/home/CDimages/s10zone/bootimage.ihaqvh ... 100% [===============================] Checking data integrity Ok Checking platform compatibility The host and the image do not have the same Solaris release: host Solaris release: 5.11 image Solaris release: 5.10 Will create a Solaris 10 branded zone. Warning: could not find a defaultrouter Zone won't have any defaultrouter configured IMAGE: ./solaris-10u10-x86.bin ZONE: s10u10 ZONEPATH: /zones/s10u10 INTERFACE: rge0 VNIC: vnicZBI13379 MAC ADDR: 2:8:20:5c:1a:cc IP ADDR: 192.168.1.100 NETMASK: 255.255.255.0 DEFROUTER: NONE TIMEZONE: US/Arizona Checking disk-space for installation Ok Installing in /zones/s10u10 ... 100% [===============================] Using a static exclusive-IP Attaching s10u10 Booting s10u10 Waiting for boot to complete booting... booting... booting... Zone s10u10 booted The zone's root password has been set using the root password of the local host. You can change the zone's root password to further harden the security of the zone: being root, log into the zone from the local host with the command 'zlogin s10u10'. Once logged in, change the root password with the command 'passwd'. The nifty part in my opinion (besides being so easy), is that the zone was created as an exclusive-IP zone on a virtual NIC. This network configuration lets you enforce traffic isolation from other zones, enforce network Quality of Service, and even let the zone set its own characteristics like IP address and packet size. Independence of the zone's network characteristics from the global zone is one of the enhancements in Solaris 10 that make it easier to consolidate zones while preserving their autonomy, yet provide control in a consolidated environment. Let's see what the virtual network environment looks like by issuing commands from the Solaris 11 global zone. First I'll use Old School ifconfig, and then I'll use the new ipadm and dladm commands. # ifconfig -a4 lo0: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL> mtu 8232 index 1 inet 127.0.0.1 netmask ff000000 rge0: flags=1004943<UP,BROADCAST,RUNNING,PROMISC,MULTICAST,DHCP,IPv4> mtu 1500 index 2 inet 192.168.1.3 netmask ffffff00 broadcast 192.168.1.255 ether 0:14:d1:18:ac:bc vboxnet0: flags=201000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4,CoS> mtu 1500 index 3 inet 192.168.56.1 netmask ffffff00 broadcast 192.168.56.255 ether 8:0:27:f8:62:1c # dladm show-phys LINK MEDIA STATE SPEED DUPLEX DEVICE yge0 Ethernet unknown 0 unknown yge0 yge1 Ethernet unknown 0 unknown yge1 rge0 Ethernet up 1000 full rge0 vboxnet0 Ethernet up 1000 full vboxnet0 # dladm show-link LINK CLASS MTU STATE OVER yge0 phys 1500 unknown -- yge1 phys 1500 unknown -- rge0 phys 1500 up -- vboxnet0 phys 1500 up -- vnicZBI13379 vnic 1500 up rge0 s10u10/vnicZBI13379 vnic 1500 up rge0 s10u10/net0 vnic 1500 up rge0 # dladm show-vnic LINK OVER SPEED MACADDRESS MACADDRTYPE VID vnicZBI13379 rge0 1000 2:8:20:5c:1a:cc random 0 s10u10/vnicZBI13379 rge0 1000 2:8:20:5c:1a:cc random 0 s10u10/net0 rge0 1000 2:8:20:9d:d0:79 random 0 # ipadm show-addr ADDROBJ TYPE STATE ADDR lo0/v4 static ok 127.0.0.1/8 rge0/_a dhcp ok 192.168.1.3/24 vboxnet0/_a static ok 192.168.56.1/24 lo0/v6 static ok ::1/128 Log into the zone The install step already booted the zone, so lets log into it. Notice how you have to be appropriately privileged to log into a zone. This is my home system so I'm being a bit cavalier, but in a production environment you can give granular control of who can login to which zones. Voila! a Solaris 10 environment under a Solaris 11 kernel. Notice the output from the uname -a and ifconfig commands, and output from a ping to a nearby host. $ zlogin s10u10 zlogin: You lack sufficient privilege to run this command (all privs required) savit@home:~$ sudo zlogin s10u10 Password: [Connected to zone 's10u10' pts/5] Oracle Corporation SunOS 5.10 Generic Patch January 2005 # uname -a SunOS s10u10 5.10 Generic_Virtual i86pc i386 i86pc # ifconfig -a4 lo0: flags=2001000849 mtu 8232 index 1 inet 127.0.0.1 netmask ff000000 vnicZBI13379: flags=1000843 mtu 1500 index 2 inet 192.168.1.100 netmask ffffff00 broadcast 192.168.1.255 ether 2:8:20:5c:1a:cc # bash bash-3.2# ifconfig -a lo0: flags=2001000849 mtu 8232 index 1 inet 127.0.0.1 netmask ff000000 vnicZBI13379: flags=1000843 mtu 1500 index 2 inet 192.168.1.100 netmask ffffff00 broadcast 192.168.1.255 ether 2:8:20:5c:1a:cc bash-3.2# ping 192.168.1.2 192.168.1.2 is alive For fun, I configured Apache (setting its configuration file in /etc/apache2) and brought it up. Easy - took just a few minutes. bash-3.2# svcs apache2 STATE STIME FMRI disabled 12:38:46 svc:/network/http:apache2 bash-3.2# svcadm enable apache2 Summary In just a few minutes, I built a functioning virtual Solaris 10 environment under by Solaris 11 system. It was... easy! While I can still do it the manual way (creating and using a system archive), this is a low-effort way to create a Solaris 10 zone on Solaris 11.

    Read the article

  • SQL SERVER – Guest Post – Jonathan Kehayias – Wait Type – Day 16 of 28

    - by pinaldave
    Jonathan Kehayias (Blog | Twitter) is a MCITP Database Administrator and Developer, who got started in SQL Server in 2004 as a database developer and report writer in the natural gas industry. After spending two and a half years working in TSQL, in late 2006, he transitioned to the role of SQL Database Administrator. His primary passion is performance tuning, where he frequently rewrites queries for better performance and performs in depth analysis of index implementation and usage. Jonathan blogs regularly on SQLBlog, and was a coauthor of Professional SQL Server 2008 Internals and Troubleshooting. On a personal note, I think Jonathan is extremely positive person. In every conversation with him I have found that he is always eager to help and encourage. Every time he finds something needs to be approved, he has contacted me without hesitation and guided me to improve, change and learn. During all the time, he has not lost his focus to help larger community. I am honored that he has accepted to provide his views on complex subject of Wait Types and Queues. Currently I am reading his series on Extended Events. Here is the guest blog post by Jonathan: SQL Server troubleshooting is all about correlating related pieces of information together to indentify where exactly the root cause of a problem lies. In my daily work as a DBA, I generally get phone calls like, “So and so application is slow, what’s wrong with the SQL Server.” One of the funny things about the letters DBA is that they go so well with Default Blame Acceptor, and I really wish that I knew exactly who the first person was that pointed that out to me, because it really fits at times. A lot of times when I get this call, the problem isn’t related to SQL Server at all, but every now and then in my initial quick checks, something pops up that makes me start looking at things further. The SQL Server is slow, we see a number of tasks waiting on ASYNC_IO_COMPLETION, IO_COMPLETION, or PAGEIOLATCH_* waits in sys.dm_exec_requests and sys.dm_exec_waiting_tasks. These are also some of the highest wait types in sys.dm_os_wait_stats for the server, so it would appear that we have a disk I/O bottleneck on the machine. A quick check of sys.dm_io_virtual_file_stats() and tempdb shows a high write stall rate, while our user databases show high read stall rates on the data files. A quick check of some performance counters and Page Life Expectancy on the server is bouncing up and down in the 50-150 range, the Free Page counter consistently hits zero, and the Free List Stalls/sec counter keeps jumping over 10, but Buffer Cache Hit Ratio is 98-99%. Where exactly is the problem? In this case, which happens to be based on a real scenario I faced a few years back, the problem may not be a disk bottleneck at all; it may very well be a memory pressure issue on the server. A quick check of the system spec’s and it is a dual duo core server with 8GB RAM running SQL Server 2005 SP1 x64 on Windows Server 2003 R2 x64. Max Server memory is configured at 6GB and we think that this should be enough to handle the workload; or is it? This is a unique scenario because there are a couple of things happening inside of this system, and they all relate to what the root cause of the performance problem is on the system. If we were to query sys.dm_exec_query_stats for the TOP 10 queries, by max_physical_reads, max_logical_reads, and max_worker_time, we may be able to find some queries that were using excessive I/O and possibly CPU against the system in their worst single execution. We can also CROSS APPLY to sys.dm_exec_sql_text() and see the statement text, and also CROSS APPLY sys.dm_exec_query_plan() to get the execution plan stored in cache. Ok, quick check, the plans are pretty big, I see some large index seeks, that estimate 2.8GB of data movement between operators, but everything looks like it is optimized the best it can be. Nothing really stands out in the code, and the indexing looks correct, and I should have enough memory to handle this in cache, so it must be a disk I/O problem right? Not exactly! If we were to look at how much memory the plan cache is taking by querying sys.dm_os_memory_clerks for the CACHESTORE_SQLCP and CACHESTORE_OBJCP clerks we might be surprised at what we find. In SQL Server 2005 RTM and SP1, the plan cache was allowed to take up to 75% of the memory under 8GB. I’ll give you a second to go back and read that again. Yes, you read it correctly, it says 75% of the memory under 8GB, but you don’t have to take my word for it, you can validate this by reading Changes in Caching Behavior between SQL Server 2000, SQL Server 2005 RTM and SQL Server 2005 SP2. In this scenario the application uses an entirely adhoc workload against SQL Server and this leads to plan cache bloat, and up to 4.5GB of our 6GB of memory for SQL can be consumed by the plan cache in SQL Server 2005 SP1. This in turn reduces the size of the buffer cache to just 1.5GB, causing our 2.8GB of data movement in this expensive plan to cause complete flushing of the buffer cache, not just once initially, but then another time during the queries execution, resulting in excessive physical I/O from disk. Keep in mind that this is not the only query executing at the time this occurs. Remember the output of sys.dm_io_virtual_file_stats() showed high read stalls on the data files for our user databases versus higher write stalls for tempdb? The memory pressure is also forcing heavier use of tempdb to handle sorting and hashing in the environment as well. The real clue here is the Memory counters for the instance; Page Life Expectancy, Free List Pages, and Free List Stalls/sec. The fact that Page Life Expectancy is fluctuating between 50 and 150 constantly is a sign that the buffer cache is experiencing constant churn of data, once every minute to two and a half minutes. If you add to the Page Life Expectancy counter, the consistent bottoming out of Free List Pages along with Free List Stalls/sec consistently spiking over 10, and you have the perfect memory pressure scenario. All of sudden it may not be that our disk subsystem is the problem, but is instead an innocent bystander and victim. Side Note: The Page Life Expectancy counter dropping briefly and then returning to normal operating values intermittently is not necessarily a sign that the server is under memory pressure. The Books Online and a number of other references will tell you that this counter should remain on average above 300 which is the time in seconds a page will remain in cache before being flushed or aged out. This number, which equates to just five minutes, is incredibly low for modern systems and most published documents pre-date the predominance of 64 bit computing and easy availability to larger amounts of memory in SQL Servers. As food for thought, consider that my personal laptop has more memory in it than most SQL Servers did at the time those numbers were posted. I would argue that today, a system churning the buffer cache every five minutes is in need of some serious tuning or a hardware upgrade. Back to our problem and its investigation: There are two things really wrong with this server; first the plan cache is excessively consuming memory and bloated in size and we need to look at that and second we need to evaluate upgrading the memory to accommodate the workload being performed. In the case of the server I was working on there were a lot of single use plans found in sys.dm_exec_cached_plans (where usecounts=1). Single use plans waste space in the plan cache, especially when they are adhoc plans for statements that had concatenated filter criteria that is not likely to reoccur with any frequency.  SQL Server 2005 doesn’t natively have a way to evict a single plan from cache like SQL Server 2008 does, but MVP Kalen Delaney, showed a hack to evict a single plan by creating a plan guide for the statement and then dropping that plan guide in her blog post Geek City: Clearing a Single Plan from Cache. We could put that hack in place in a job to automate cleaning out all the single use plans periodically, minimizing the size of the plan cache, but a better solution would be to fix the application so that it uses proper parameterized calls to the database. You didn’t write the app, and you can’t change its design? Ok, well you could try to force parameterization to occur by creating and keeping plan guides in place, or we can try forcing parameterization at the database level by using ALTER DATABASE <dbname> SET PARAMETERIZATION FORCED and that might help. If neither of these help, we could periodically dump the plan cache for that database, as discussed as being a problem in Kalen’s blog post referenced above; not an ideal scenario. The other option is to increase the memory on the server to 16GB or 32GB, if the hardware allows it, which will increase the size of the plan cache as well as the buffer cache. In SQL Server 2005 SP1, on a system with 16GB of memory, if we set max server memory to 14GB the plan cache could use at most 9GB  [(8GB*.75)+(6GB*.5)=(6+3)=9GB], leaving 5GB for the buffer cache.  If we went to 32GB of memory and set max server memory to 28GB, the plan cache could use at most 16GB [(8*.75)+(20*.5)=(6+10)=16GB], leaving 12GB for the buffer cache. Thankfully we have SQL Server 2005 Service Pack 2, 3, and 4 these days which include the changes in plan cache sizing discussed in the Changes to Caching Behavior between SQL Server 2000, SQL Server 2005 RTM and SQL Server 2005 SP2 blog post. In real life, when I was troubleshooting this problem, I spent a week trying to chase down the cause of the disk I/O bottleneck with our Server Admin and SAN Admin, and there wasn’t much that could be done immediately there, so I finally asked if we could increase the memory on the server to 16GB, which did fix the problem. It wasn’t until I had this same problem occur on another system that I actually figured out how to really troubleshoot this down to the root cause.  I couldn’t believe the size of the plan cache on the server with 16GB of memory when I actually learned about this and went back to look at it. SQL Server is constantly telling a story to anyone that will listen. As the DBA, you have to sit back and listen to all that it’s telling you and then evaluate the big picture and how all the data you can gather from SQL about performance relate to each other. One of the greatest tools out there is actually a free in the form of Diagnostic Scripts for SQL Server 2005 and 2008, created by MVP Glenn Alan Berry. Glenn’s scripts collect a majority of the information that SQL has to offer for rapid troubleshooting of problems, and he includes a lot of notes about what the outputs of each individual query might be telling you. When I read Pinal’s blog post SQL SERVER – ASYNC_IO_COMPLETION – Wait Type – Day 11 of 28, I noticed that he referenced Checking Memory Related Performance Counters in his post, but there was no real explanation about why checking memory counters is so important when looking at an I/O related wait type. I thought I’d chat with him briefly on Google Talk/Twitter DM and point this out, and offer a couple of other points I noted, so that he could add the information to his blog post if he found it useful.  Instead he asked that I write a guest blog for this. I am honored to be a guest blogger, and to be able to share this kind of information with the community. The information contained in this blog post is a glimpse at how I do troubleshooting almost every day of the week in my own environment. SQL Server provides us with a lot of information about how it is running, and where it may be having problems, it is up to us to play detective and find out how all that information comes together to tell us what’s really the problem. This blog post is written by Jonathan Kehayias (Blog | Twitter). Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: MVP, Pinal Dave, PostADay, Readers Contribution, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

    Read the article

< Previous Page | 547 548 549 550 551 552 553 554 555 556 557 558  | Next Page >