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  • C# in Depth, Third Edition by Jon Skeet, Manning Publications Co. Book Review

    - by Compudicted
    Originally posted on: http://geekswithblogs.net/Compudicted/archive/2013/10/24/c-in-depth-third-edition-by-jon-skeet-manning-publications.aspx I started reading this ebook on September 28, 2013, the same day it was sent my way by Manning Publications Co. for review while it still being fresh off the press. So 1st thing – thanks to Manning for this opportunity and a free copy of this must have on every C# developer’s desk book! Several hours ago I finished reading this book (well, except a for a large portion of its quite lengthy appendix). I jumped writing this review right away while still being full of emotions and impressions from reading it thoroughly and running code examples. Before I go any further I would like say that I used to program on various platforms using various languages starting with the Mainframe and ending on Windows, and I gradually shifted toward dealing with databases more than anything, however it happened with me to program in C# 1 a lot when it was first released and then some C# 2 with a big leap in between to C# 5. So my perception and experience reading this book may differ from yours. Also what I want to tell is somewhat funny that back then, knowing some Java and seeing C# 1 released, initially made me drawing a parallel that it is a copycat language, how wrong was I… Interestingly, Jon programs in Java full time, but how little it was mentioned in the book! So more on the book: Be informed, this is not a typical “Recipes”, “Cookbook” or any set of ready solutions, it is rather targeting mature, advanced developers who do not only know how to use a number of features, but are willing to understand how the language is operating “under the hood”. I must state immediately, at the same time I am glad the author did not go into the murky depths of the MSIL, so this is a very welcome decision on covering a modern language as C# for me, thank you Jon! Frankly, not all was that rosy regarding the tone and structure of the book, especially the the first half or so filled me with several negative and positive emotions overpowering each other. To expand more on that, some statements in the book appeared to be bias to me, or filled with pre-justice, it started to look like it had some PR-sole in it, but thankfully this was all gone toward the end of the 1st third of the book. Specifically, the mention on the C# language popularity, Java is the #1 language as per https://sites.google.com/site/pydatalog/pypl/PyPL-PopularitY-of-Programming-Language (many other sources put C at the top which I highly doubt), also many interesting functional languages as Clojure and Groovy appeared and gained huge traction which run on top of Java/JVM whereas C# does not enjoy such a situation. If we want to discuss the popularity in general and say how fast a developer can find a new job that pays well it would be indeed the very Java, C++ or PHP, never C#. Or that phrase on language preference as a personal issue? We choose where to work or we are chosen because of a technology used at a given software shop, not vice versa. The book though it technically very accurate with valid code, concise examples, but I wish the author would give more concrete, real-life examples on where each feature should be used, not how. Another point to realize before you get the book is that it is almost a live book which started to be written when even C# 3 wasn’t around so a lot of ground is covered (nearly half of the book) on the pre-C# 3 feature releases so if you already have a solid background in the previous releases and do not plan to upgrade, perhaps half of the book can be skipped, otherwise this book is surely highly recommended. Alas, for me it was a hard read, most of it. It was not boring (well, only may be two times), it was just hard to grasp some concepts, but do not get me wrong, it did made me pause, on several occasions, and made me read and re-read a page or two. At times I even wondered if I have any IQ at all (LOL). Be prepared to read A LOT on generics, not that they are widely used in the field (I happen to work as a consultant and went thru a lot of code at many places) I can tell my impression is the developers today in best case program using examples found at OpenStack.com. Also unlike the Java world where having the most recent version is nearly mandated by the OSS most companies on the Microsoft platform almost never tempted to upgrade the .Net version very soon and very often. As a side note, I was glad to see code recently that included a nullable variable (myvariable? notation) and this made me smile, besides, I recommended that person this book to expand her knowledge. The good things about this book is that Jon maintains an active forum, prepared code snippets and even a small program (Snippy) that is happy to run the sample code saving you from writing any plumbing code. A tad now on the C# language itself – it sure enjoyed a wonderful road toward perfection and a very high adoption, especially for ASP development. But to me all the recent features that made this statically typed language more dynamic look strange. Don’t we have F#? Which supposed to be the dynamic language? Why do we need to have a hybrid language? Now the developers live their lives in dualism of the static and dynamic variables! And LINQ to SQL, it is covered in depth, but wasn’t it supposed to be dropped? Also it seems that very little is being added, and at a slower pace, e.g. Roslyn will come in late 2014 perhaps, and will be probably the only main feature. Again, it is quite hard to read this book as various chapters, C# versions mentioned every so often only if I only could remember what was covered exactly where! So the fact it has so many jumps/links back and forth I recommend the ebook format to make the navigations easier to perform and I do recommend using software that allows bookmarking, also make sure you have access to plenty of coffee and pizza (hey, you probably know this joke – who a programmer is) ! In terms of closing, if you stuck at C# 1 or 2 level, it is time to embrace the power of C# 5! Finally, to compliment Manning, this book unlike from any other publisher so far, was the only one as well readable (put it formatted) on my tablet as in Adobe Reader on a laptop.

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  • 202 blog articles

    - by mprove
    All my blog articles under blogs.oracle.com since August 2005: 202 blog articles Apr 2012 blogs.oracle.com design patch Mar 2012 Interaction 12 - Critique Mar 2012 Typing. Clicking. Dancing. Feb 2012 Desktop Mobility in Hospitals with Oracle VDI /video Feb 2012 Interaction 12 in Dublin - Highlights of Day 3 Feb 2012 Interaction 12 in Dublin - Highlights of Day 2 Feb 2012 Interaction 12 in Dublin - Highlights of Day 1 Feb 2012 Shit Interaction Designers Say Feb 2012 Tips'n'Tricks for WebCenter #3: How to display custom page titles in Spaces Jan 2012 Tips'n'Tricks for WebCenter #2: How to create an Admin menu in Spaces and save a lot of time Jan 2012 Tips'n'Tricks for WebCenter #1: How to apply custom resources in Spaces Jan 2012 Merry XMas and a Happy 2012! Dec 2011 One Year Oracle SocialChat - The Movie Nov 2011 Frank Ludolph's Last Working Day Nov 2011 Hans Rosling at TED Oct 2011 200 Countries x 200 Years Oct 2011 Blog Aggregation for Desktop Virtualization Oct 2011 Oracle VDI at OOW 2011 Sep 2011 Design for Conversations & Conversations for Design Sep 2011 All Oracle UX Blogs Aug 2011 Farewell Loriot Aug 2011 Oracle VDI 3.3 Overview Aug 2011 Sutherland's Closing Remarks at HyperKult Aug 2011 Surface and Subface Aug 2011 Back to Childhood in UI Design Jul 2011 The Art of Engineering and The Engineering of Art Jul 2011 Oracle VDI Seminar - June-30 Jun 2011 SGD White Paper May 2011 TEDxHamburg Live Feed May 2011 Oracle VDI in 3 Minutes May 2011 Space Ship Earth 2011 May 2011 blog moving times Apr 2011 Frozen tag cloud Apr 2011 Oracle: Hardware Software Complete in 1953 Apr 2011 Interaction Design with Wireframes Apr 2011 A guide to closing down a project Feb 2011 Oracle VDI 3.2.2 Jan 2011 free VDI charts Jan 2011 Sun Founders Panel 2006 Dec 2010 Sutherland on Leadership Dec 2010 SocialChat: Efficiency of E20 Dec 2010 ALWAYS ON Desktop Virtualization Nov 2010 12,000 Desktops at JavaOne Nov 2010 SocialChat on Sharing Best Practices Oct 2010 Globe of Visitors Oct 2010 SocialChat about the Next Big Thing Oct 2010 Oracle VDI UX Story - Wireframes Oct 2010 What's a PC anyway? Oct 2010 SocialChat on Getting Things Done Oct 2010 SocialChat on Infoglut Oct 2010 IT Twenty Twenty Oct 2010 Desktop Virtualization Webcasts from OOW Oct 2010 Oracle VDI 3.2 Overview Sep 2010 Blog Usability Top 7 Sep 2010 100 and counting Aug 2010 Oracle'izing the VDI Blogs Aug 2010 SocialChat on Apple Aug 2010 SocialChat on Video Conferencing Aug 2010 Oracle VDI 3.2 - Features and Screenshots Aug 2010 SocialChat: Don't stop making waves Aug 2010 SocialChat: Giving Back to the Community Aug 2010 SocialChat on Learning in Meetings Aug 2010 iPAD's Natural User Interface Jul 2010 Last day for Sun Microsystems GmbH Jun 2010 SirValUse Celebration Snippets Jun 2010 10 years SirValUse - Happy Birthday! Jun 2010 Wim on Virtualization May 2010 New Home for Oracle VDI Apr 2010 Renaissance Slide Sorter Comments Apr 2010 Unboxing Sun Ray 3 Plus Apr 2010 Desktop Virtualisierung mit Sun VDI 3.1 Apr 2010 Blog Relaunch Mar 2010 Social Messaging Slides from CeBIT Mar 2010 Social Messaging Talk at CeBIT Feb 2010 Welcome Oracle Jan 2010 My last presentation at Sun Jan 2010 Ivan Sutherland on Leadership Jan 2010 Learning French with Sun VDI Jan 2010 Learning Danish with Sun Ray Jan 2010 VDI workshop in Nieuwegein Jan 2010 Happy New Year 2010 Jan 2010 On Creating Slides Dec 2009 Best VDI Ever Nov 2009 How to store the Big Bang Nov 2009 Social Enterprise Tools. Beipiel Sun. Nov 2009 Nov-19 Nov 2009 PDF and ODF links on your blog Nov 2009 Q&A on VDI and MySQL Cluster Nov 2009 Zürich next week: Swiss Intranet Summit 09 Nov 2009 Designing for a Sustainable World - World Usabiltiy Day, Nov-12 Nov 2009 How to export a desktop from VDI 3 Nov 2009 Virtualisation Roadshow in the UK Nov 2009 Project Wonderland at EDUCAUSE 09 Nov 2009 VDI Roadshow in Dublin, Nov-26, 2009 Nov 2009 Sun VDI at EDUCAUSE 09 Nov 2009 Sun VDI 3.1 Architecture and New Features Oct 2009 VDI 3.1 is Early-Access Sep 2009 Virtualization for MySQL on VMware Sep 2009 Silpion & 13. Stock Sommerparty Sep 2009 Sun Ray and VMware View 3.1.1 2009-08-31 New Set of Sun Ray Status Icons 2009-08-25 Virtualizing the VDI Core? 2009-08-23 World Usability Day Hamburg 2009 - CfP 2009-07-16 Rising Sun 2009-07-15 featuring twittermeme 2009-06-19 ISC09 Student Party on June-20 /Hamburg 2009-06-18 Before and behind the curtain of JavaOne 2009-06-09 20k desktops at JavaOne 2009-06-01 sweet microblogging 2009-05-25 VDI 3 - Why you need 3 VDI hosts and what you can do about that? 2009-05-21 IA Konferenz 2009 2009-05-20 Sun VDI 3 UX Story - Power of the Web 2009-05-06 Planet of Sun and Oracle User Experience Design 2009-04-22 Sun VDI 3 UX Story - User Research 2009-04-08 Sun VDI 3 UX Story - Concept Workshops 2009-04-06 Localized documentation for Sun Ray Connector for VMware View Manager 1.1 2009-04-03 Sun VDI 3 Press Release 2009-03-25 Sun VDI 3 launches today! 2009-03-25 Sun Ray Connector for VMware View Manager 1.1 Update 2009-03-11 desktop virtualization wiki relaunch 2009-03-06 VDI 3 at CeBIT hall 6, booth E36 2009-03-02 Keyboard layout problems with Sun Ray Connector for VMware VDM 2009-02-23 wikis.sun.com tips & tricks 2009-02-23 Sun VDI 3 is in Early Access 2009-02-09 VirtualCenter unable to decrypt passwords 2009-02-02 Sun & VMware Desktop Training 2009-01-30 VDI at next09? 2009-01-16 Sun VDI: How to use virtual machines with multiple network adapters 2009-01-07 Sun Ray and VMware View 2009-01-07 Hamburg World Usability Day 2008 - Webcasts 2009-01-06 Sun Ray Connector for VMware VDM slides 2008-12-15 mother of all demos 2008-12-08 Build your own Thumper 2008-12-03 Troubleshooting Sun Ray Connector for VMware VDM 2008-12-02 My Roller Tag Cloud 2008-11-28 Sun Ray Connector: SSL connection to VDM 2008-11-25 Setting up SSL and Sun Ray Connector for VMware VDM 2008-11-13 Inspiration for Today and Tomorrow 2008-10-23 Sun Ray Connector for VMware VDM released 2008-10-14 From Sketchpad to ILoveSketch 2008-10-09 Desktop Virtualization on Xing 2008-10-06 User Experience Forum on Xing 2008-10-06 Sun Ray Connector for VMware VDM certified 2008-09-17 Virtual Clouds over Las Vegas 2008-09-14 Bill Verplank sketches metaphors 2008-09-04 End of Early Access - Sun Ray Connector for VMware 2008-08-27 Early Access: Sun Ray Connector for VMware Virtual Desktop Manager 2008-08-12 Sun Virtual Desktop Connector - Insides on Recycling Part 2 2008-07-20 Sun Virtual Desktop Connector - Insides on Recycling Part 3 2008-07-20 Sun Virtual Desktop Connector - Insides on Recycling 2008-07-20 lost in wiki space 2008-07-07 Evolution of the Desktop 2008-06-17 Virtual Desktop Webcast 2008-06-16 Woodstock 2008-06-16 What's a Desktop PC anyway? 2008-06-09 Virtual-T-Box 2008-06-05 Virtualization Glossary 2008-05-06 Five User Experience Principles 2008-04-25 Virtualization News Feed 2008-04-21 Acetylcholinesterase - Second Season 2008-04-18 Acetylcholinesterase - End of Signal 2007-12-31 Produkt-Management ist... 2007-10-22 Usability Verbände, Verteiler und Netzwerke. 2007-10-02 The Meaning is the Message 2007-09-28 Visualization Methods 2007-09-10 Inhouse und Open Source Projekte – Usability verankern und Synergien nutzen 2007-09-03 Der Schwabe Darth Vader entdeckt das Virale Marketing 2007-08-29 Dick Hardt 3.0 on Identity 2.0 2007-08-27 quality of written text depends on the tool 2007-07-27 podcasts for reboot9 2007-06-04 It is the user's itch that need to be scratched 2007-05-25 A duel at reboot9 2007-05-14 Taxonomien und Folksonomien - Tagging als neues HCI-Element 2007-05-10 Dueling Interaction Models of Personal-Computing and Web-Computing 2007-03-01 22.März: Weizenbaum. Rebel at Work. /Filmpremiere Hamburg 2007-02-25 Bruce Sterling at UbiComp 2006 /webcast 2006-11-12 FSOSS 2006 /webcasts 2006-11-10 Highway 101 2006-11-09 User Experience Roundtable Hamburg: EuroGEL 2006 2006-11-08 Douglas Adams' Hyperland (BBC 1990) 2006-10-08 Taxonomien und Folksonomien – Tagging als neues HCI-Element 2006-09-13 Usability im Unternehmen 2006-09-13 Doug does HyperScope 2006-08-26 TED Talks and TechTalks 2006-08-21 Kai Krause über seine Freundschaft zu Douglas Adams 2006-07-20 Rebel At Work: Film Portrait on Weizenbaum 2006-07-04 Gabriele Fischer, mp3 2006-06-07 Dick Hardt at ETech 06 2006-06-05 Weinberger: From Control to Conversation 2006-04-16 Eye Tracking at User Experience Roundtable Hamburg 2006-04-14 dropping knowledge 2006-04-09 GEL 2005 2006-03-13 slide photos of reboot7 2006-03-04 Dick Hardt on Identity 2.0 2006-02-28 User Experience Newsletter #13: Versioning 2006-02-03 Ester Dyson on Choice and Happyness 2006-02-02 Requirements-Engineering im Spannungsfeld von Individual- und Produktsoftware 2006-01-15 User Experience Newsletter #12: Intuition Quiz 2005-11-30 User Experience und Requirements-Engineering für Software-Projekte 2005-10-31 Ivan Sutherland on "Research and Fun" 2005-10-18 Ars Electronica / Mensch und Computer 2005 2005-09-14 60 Jahre nach Memex: Über die Unvereinbarkeit von Desktop- und Web-Paradigma 2005-08-31 reboot 7 2005-06-30

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  • So, how is the Oracle HCM Cloud User Experience? In a word, smokin’!

    - by Edith Mireles-Oracle
    By Misha Vaughan, Oracle Applications User Experience Oracle unveiled its game-changing cloud user experience strategy at Oracle OpenWorld 2013 (remember that?) with a new simplified user interface (UI) paradigm.  The Oracle HCM cloud user experience is about light-weight interaction, tailored to the task you are trying to accomplish, on the device you are comfortable working with. A key theme for the Oracle user experience is being able to move from smartphone to tablet to desktop, with all of your data in the cloud. The Oracle HCM Cloud user experience provides designs for better productivity, no matter when and how your employees need to work. Release 8  Oracle recently demonstrated how fast it is moving development forward for our cloud applications, with the availability of release 8.  In release 8, users will see expanded simplicity in the HCM cloud user experience, such as filling out a time card and succession planning. Oracle has also expanded its mobile capabilities with task flows for payslips, managing absences, and advanced analytics. In addition, users will see expanded extensibility with the new structures editor for simplified pages, and the with the user interface text editor, which allows you to update language throughout the UI from one place. If you don’t like calling people who work for you “employees,” you can use this tool to create a term that is suited to your business.  Take a look yourself at what’s available now. What are people saying?Debra Lilley (@debralilley), an Oracle ACE Director who has a long history with Oracle Applications, recently gave her perspective on release 8: “Having had the privilege of seeing a preview of release 8, I am again impressed with the enhancements around simplified UI. Even more so, at a user group event in London this week, an existing Cloud HCM customer speaking publically about his implementation said he was very excited about release 8 as the absence functionality was so superior and simple to use.”  In an interview with Lilley for a blog post by Dennis Howlett  (@dahowlett), we probably couldn’t have asked for a more even-handed look at the Oracle Applications Cloud and the impact of user experience. Take the time to watch all three videos and get the full picture.  In closing, Howlett’s said: “There is always the caveat that getting from the past to Fusion [from the editor: Fusion is now called the Oracle Applications Cloud] is not quite as simple as may be painted, but the outcomes are much better than anticipated in large measure because the user experience is so much better than what went before.” Herman Slange, Technical Manager with Oracle Applications partner Profource, agrees with that comment. “We use on-premise Financials & HCM for internal use. Having a simple user interface that works on a desktop as well as a tablet for (very) non-technical users is a big relief. Coming from E-Business Suite, there is less training (none) required to access HCM content.  From a technical point of view, having the abilities to tailor the simplified UI very easy makes it very efficient for us to adjust to specific customer needs.  When we have a conversation about simplified UI, we just hand over a tablet and ask the customer to just use it. No training and no explanation required.” Finally, in a story by Computer Weekly  about Oracle customer BG Group, a natural gas exploration and production company based in the UK and with a presence in 20 countries, the author states: “The new HR platform has proved to be easier and more intuitive for HR staff to use than the previous SAP-based technology.” What’s Next for Oracle’s Applications Cloud User Experiences? This is the question that Steve Miranda, Oracle Executive Vice President, Applications Development, asks the Applications User Experience team, and we’ve been hard at work for some time now on “what’s next.”  I can’t say too much about it, but I can tell you that we’ve started talking to customers and partners, under non-disclosure agreements, about user experience concepts that we are working on in order to get their feedback. We recently had a chance to talk about possibilities for the Oracle HCM Cloud user experience at an Oracle HCM Southern California Customer Success Summit. This was a fantastic event, hosted by Shane Bliss and Vance Morossi of the Oracle Client Success Team. We got to use the uber-slick facilities of Allergan, our hosts (of Botox fame), headquartered in Irvine, Calif., with a presence in more than 100 countries. Photo by Misha Vaughan, Oracle Applications User Experience Vance Morossi, left, and Shane Bliss, of the Oracle Client Success Team, at an Oracle HCM Southern California Customer Success Summit.  We were treated to a few really excellent talks around human resources (HR). Alice White, VP Human Resources, discussed Allergan's process for global talent acquisition -- how Allergan has designed and deployed a global process, and global tools, along with Oracle and Cognizant, and are now at the end of a global implementation. She shared a couple of insights about the journey for Allergan: “One of the major areas for improvement was on role clarification within the company.” She said the company is “empowering managers and deputizing them as recruiters. Now it is a global process that is nimble and efficient."  Deepak Rammohan, VP Product Management, HCM Cloud, Oracle, also took the stage to talk about pioneering modern HR. He reflected modern HR problems of getting the right data about the workforce, the importance of getting the right talent as a key strategic initiative, and other workforce insights. "How do we design systems to deal with all of this?” he asked. “Make sure the systems are talent-centric. The next piece is collaborative, engaging, and mobile. A lot of this is influenced by what users see today. The last thing is around insight; insight at the point of decision-making." Rammohan showed off some killer HCM Cloud talent demos focused on simplicity and mobility that his team has been cooking up, and closed with a great line about the nature of modern recruiting: "Recruiting is a team sport." Deepak Rammohan, left, and Jake Kuramoto, both of Oracle, debate the merits of a Google Glass concept demo for recruiters on-the-go. Later, in an expo-style format, the Apps UX team showed several concepts for next-generation HCM Cloud user experiences, including demos shown by Jake Kuramoto (@jkuramoto) of The AppsLab, and Aylin Uysal (@aylinuysal), Director, HCM Cloud user experience. We even hauled out our eye-tracker, a research tool used to show where the eye is looking at a particular screen, thanks to teammate Michael LaDuke. Dionne Healy, HCM Client Executive, and Aylin Uysal, Director, HCM Cloud user experiences, Oracle, take a look at new HCM Cloud UX concepts. We closed the day with Jeremy Ashley (@jrwashley), VP, Applications User Experience, who brought it all back together by talking about the big picture for applications cloud user experiences. He covered the trends we are paying attention to now, what users will be expecting of their modern enterprise apps, and what Oracle’s design strategy is around these ideas.   We closed with an excellent reception hosted by ADP Payroll services at Bistango. Want to read more?Want to see where our cloud user experience is going next? Read more on the UsableApps web site about our latest design initiative: “Glance, Scan, Commit.” Or catch up on the back story by looking over our Applications Cloud user experience content on the UsableApps web site.  You can also find out where we’ll be next at the Events page on UsableApps.

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  • What's up with LDoms: Part 4 - Virtual Networking Explained

    - by Stefan Hinker
    I'm back from my summer break (and some pressing business that kept me away from this), ready to continue with Oracle VM Server for SPARC ;-) In this article, we'll have a closer look at virtual networking.  Basic connectivity as we've seen it in the first, simple example, is easy enough.  But there are numerous options for the virtual switches and virtual network ports, which we will discuss in more detail now.   In this section, we will concentrate on virtual networking - the capabilities of virtual switches and virtual network ports - only.  Other options involving hardware assignment or redundancy will be covered in separate sections later on. There are two basic components involved in virtual networking for LDoms: Virtual switches and virtual network devices.  The virtual switch should be seen just like a real ethernet switch.  It "runs" in the service domain and moves ethernet packets back and forth.  A virtual network device is plumbed in the guest domain.  It corresponds to a physical network device in the real world.  There, you'd be plugging a cable into the network port, and plug the other end of that cable into a switch.  In the virtual world, you do the same:  You create a virtual network device for your guest and connect it to a virtual switch in a service domain.  The result works just like in the physical world, the network device sends and receives ethernet packets, and the switch does all those things ethernet switches tend to do. If you look at the reference manual of Oracle VM Server for SPARC, there are numerous options for virtual switches and network devices.  Don't be confused, it's rather straight forward, really.  Let's start with the simple case, and work our way to some more sophisticated options later on.  In many cases, you'll want to have several guests that communicate with the outside world on the same ethernet segment.  In the real world, you'd connect each of these systems to the same ethernet switch.  So, let's do the same thing in the virtual world: root@sun # ldm add-vsw net-dev=nxge2 admin-vsw primary root@sun # ldm add-vnet admin-net admin-vsw mars root@sun # ldm add-vnet admin-net admin-vsw venus We've just created a virtual switch called "admin-vsw" and connected it to the physical device nxge2.  In the physical world, we'd have powered up our ethernet switch and installed a cable between it and our big enterprise datacenter switch.  We then created a virtual network interface for each one of the two guest systems "mars" and "venus" and connected both to that virtual switch.  They can now communicate with each other and with any system reachable via nxge2.  If primary were running Solaris 10, communication with the guests would not be possible.  This is different with Solaris 11, please see the Admin Guide for details.  Note that I've given both the vswitch and the vnet devices some sensible names, something I always recommend. Unless told otherwise, the LDoms Manager software will automatically assign MAC addresses to all network elements that need one.  It will also make sure that these MAC addresses are unique and reuse MAC addresses to play nice with all those friendly DHCP servers out there.  However, if we want to do this manually, we can also do that.  (One reason might be firewall rules that work on MAC addresses.)  So let's give mars a manually assigned MAC address: root@sun # ldm set-vnet mac-addr=0:14:4f:f9:c4:13 admin-net mars Within the guest, these virtual network devices have their own device driver.  In Solaris 10, they'd appear as "vnet0".  Solaris 11 would apply it's usual vanity naming scheme.  We can configure these interfaces just like any normal interface, give it an IP-address and configure sophisticated routing rules, just like on bare metal.  In many cases, using Jumbo Frames helps increase throughput performance.  By default, these interfaces will run with the standard ethernet MTU of 1500 bytes.  To change this,  it is usually sufficient to set the desired MTU for the virtual switch.  This will automatically set the same MTU for all vnet devices attached to that switch.  Let's change the MTU size of our admin-vsw from the example above: root@sun # ldm set-vsw mtu=9000 admin-vsw primary Note that that you can set the MTU to any value between 1500 and 16000.  Of course, whatever you set needs to be supported by the physical network, too. Another very common area of network configuration is VLAN tagging. This can be a little confusing - my advise here is to be very clear on what you want, and perhaps draw a little diagram the first few times.  As always, keeping a configuration simple will help avoid errors of all kind.  Nevertheless, VLAN tagging is very usefull to consolidate different networks onto one physical cable.  And as such, this concept needs to be carried over into the virtual world.  Enough of the introduction, here's a little diagram to help in explaining how VLANs work in LDoms: Let's remember that any VLANs not explicitly tagged have the default VLAN ID of 1. In this example, we have a vswitch connected to a physical network that carries untagged traffic (VLAN ID 1) as well as VLANs 11, 22, 33 and 44.  There might also be other VLANs on the wire, but the vswitch will ignore all those packets.  We also have two vnet devices, one for mars and one for venus.  Venus will see traffic from VLANs 33 and 44 only.  For VLAN 44, venus will need to configure a tagged interface "vnet44000".  For VLAN 33, the vswitch will untag all incoming traffic for venus, so that venus will see this as "normal" or untagged ethernet traffic.  This is very useful to simplify guest configuration and also allows venus to perform Jumpstart or AI installations over this network even if the Jumpstart or AI server is connected via VLAN 33.  Mars, on the other hand, has full access to untagged traffic from the outside world, and also to VLANs 11,22 and 33, but not 44.  On the command line, we'd do this like this: root@sun # ldm add-vsw net-dev=nxge2 pvid=1 vid=11,22,33,44 admin-vsw primary root@sun # ldm add-vnet admin-net pvid=1 vid=11,22,33 admin-vsw mars root@sun # ldm add-vnet admin-net pvid=33 vid=44 admin-vsw venus Finally, I'd like to point to a neat little option that will make your live easier in all those cases where configurations tend to change over the live of a guest system.  It's the "id=<somenumber>" option available for both vswitches and vnet devices.  Normally, Solaris in the guest would enumerate network devices sequentially.  However, it has ways of remembering this initial numbering.  This is good in the physical world.  In the virtual world, whenever you unbind (aka power off and disassemble) a guest system, remove and/or add network devices and bind the system again, chances are this numbering will change.  Configuration confusion will follow suit.  To avoid this, nail down the initial numbering by assigning each vnet device it's device-id explicitly: root@sun # ldm add-vnet admin-net id=1 admin-vsw venus Please consult the Admin Guide for details on this, and how to decipher these network ids from Solaris running in the guest. Thanks for reading this far.  Links for further reading are essentially only the Admin Guide and Reference Manual and can be found above.  I hope this is useful and, as always, I welcome any comments.

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  • Making Money from your SQL Server Blog

    - by Bill Graziano
    My SQL Server blog reading list is around one hundred blogs.  Many people are writing great content and generating lots of page views.  I see some of them running Google AdSense and trying to make a little money off their traffic.  If you want to earn some some extra money from what you’ve written there are a couple of options.  And one new option that I’m announcing here. Background Internet advertising is sold based on a few different pricing schemes.  Flat Fee.  You offer either all your impressions (page views) or some percentage of your impressions in exchange for a flat monthly fee.  CPM or cost per thousand impressions.  If the quoted price is $2 CPM you’ll get $2 for every 1,000 times the ad is displayed.  While you might think the “M” means millions, the “M” in CPM is the roman numeral for 1,000. CPC or cost per click.  This is also called PPC or pay per click.  In this method you get paid based on how many clicks there are on the ad.  CPA or cost per action.  In this method you get paid based on an action that occurs on the advertisers site after they click on the ad.  This is typically some type of sign up form.  This is how most affiliate programs work. Darren Rowse at ProBlogger has been writing about blogging and making money off blogs for years.  He has a good introduction to making money on your blog in his “Making Money” section.  If you’re interested in learning more he has a post up titled How to Make More Money From Your Blog in the New Year that links to many of his best posts on the subject. Google AdSense This is the most common method for people earning money from their blogging.  It’s easy to setup and administer.  You tell AdSense what size ads you’d like to run and it gives you a little piece of JavaScript to put on your site.  AdSense quickly learns the topics you write about and displays ads that are appropriate for your site.  I typically see ads for hosting, SQL Server tools and developer tools running in AdSense slots.  AdSense pays on a CPC model.  If you translate that back to CPM pricing you’ll see rates from $0.50 to $1.00 CPM. Amazon While you might not make much money writing books it’s now possible to make even less helping Amazon sell them.  You can sign up for an Amazon affiliate program.  Each time you send Amazon a link and someone buys the book you get a cut of that sale.  This is the CPA model from above.  Amazon can help you build some pretty nice “stores”.  Here’s the SQL Server bookstore I built for SQLTeam.com.  If you’re just putting in a page with books like I’ve done on SQLTeam you should keep your expectations low.  If you’re writing book reviews of suggesting books on your blog it really does make sense to setup an Amazon affiliate link.  People are much more likely to buy a book based on a review from a trusted source.  I always try to buy through a referral link if there is one. Amazon pays about 4% of the price as a referral fee.  You also get credit for anything else they buy while on the site.  I recently had someone buy an iPod nano with their SQL Server book making me an extra $5.60 richer!  Estimating how much you can make is difficult though.  How much attention you draw to the links and book reviews can dramatically affect the earnings. Private Ad Sales This is the hardest but potentially most lucrative option.  You sell advertising directly to companies that want to sell things to your readers.  Typically this would be SQL Server tool vendors, hosting companies or anyone else that wants to make money off database administrators.  This is also the most difficult to do.  You’ll need the contacts at the companies and enough page views to make it worth their while.  You’ll also need software to track the page views and clicks, geo-target your ads and smooth out the impressions.  Your earnings are based on whatever you can negotiate with the companies. SQL Server Ad Network For the last couple of years I’ve run any extra ads that I sold on the SQLTeam Weblogs.  You can see an example of that on Mladen’s blog.  The ad in the upper right corner is one that I’m running for him.  (Note: Many of the ads I’m running are geo-targeted to only appear in English speaking countries.  You may see a different set of ads outside the US, Canada and the UK.  You can also see he has a couple of Google ads on his blog.)  When I run ads on his blog I split the advertising revenue with him.  They make a little and I make a little. I recently started to expand this and sell advertising specifically to run on SQL Server-related blogs.  I’m also starting to run ads on non-SQLTeam blogs.  The only way I can sell more advertising is to have more blogs to run it on.  And that’s where you come in. I’ve created a SQL Server advertising network.  I handle all the ad sales and provide the technology to serve the ads.  I handle collections and payments back to you.  You get paid at the end of each month regardless of when (or if) the advertiser actually pays.  All you need to do is add a small piece of JavaScript to your site to display the ads. If you’re writing about SQL Server and interested in earning a little money for your site I’d like to talk to you.  You can use the Contact Us page on SQLTeam.com to reach me.  Running advertising on your blog isn’t for everyone.  If you’re concerned about what advertisers might think about certain posts then you might not be a good fit.  For the most part this isn’t an issue.  You’ll also need to have a PayPal account to receive payments.  You probably won’t get rich doing this.  But you can earn extra cash on the side for doing what you would do anyway.  I do know that people have earned enough to buy themselves a nice laptop doing this. My initial target is blogs with more than 10,000 page views per month.  I expect to pay two to three times what Google pays.  If you have less than 10,000 page views per month but are still interested I’d still like to hear from you.  I may not be able to sign up smaller blogs right away but we’ll get the process started.  If you’re unsure about your traffic Google Analytics is a free tool that provides great reporting on traffic, popular posts and how people find your blog.  If you have any questions or are just curious drop me a line and I’ll try to answer your questions.

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  • MVC 3 AdditionalMetadata Attribute with ViewBag to Render Dynamic UI

    - by Steve Michelotti
    A few months ago I blogged about using Model metadata to render a dynamic UI in MVC 2. The scenario in the post was that we might have a view model where the questions are conditionally displayed and therefore a dynamic UI is needed. To recap the previous post, the solution was to use a custom attribute called [QuestionId] in conjunction with an “ApplicableQuestions” collection to identify whether each question should be displayed. This allowed me to have a view model that looked like this: 1: [UIHint("ScalarQuestion")] 2: [DisplayName("First Name")] 3: [QuestionId("NB0021")] 4: public string FirstName { get; set; } 5: 6: [UIHint("ScalarQuestion")] 7: [DisplayName("Last Name")] 8: [QuestionId("NB0022")] 9: public string LastName { get; set; } 10: 11: [UIHint("ScalarQuestion")] 12: [QuestionId("NB0023")] 13: public int Age { get; set; } 14: 15: public IEnumerable<string> ApplicableQuestions { get; set; } At the same time, I was able to avoid repetitive IF statements for every single question in my view: 1: <%: Html.EditorFor(m => m.FirstName, new { applicableQuestions = Model.ApplicableQuestions })%> 2: <%: Html.EditorFor(m => m.LastName, new { applicableQuestions = Model.ApplicableQuestions })%> 3: <%: Html.EditorFor(m => m.Age, new { applicableQuestions = Model.ApplicableQuestions })%> by creating an Editor Template called “ScalarQuestion” that encapsulated the IF statement: 1: <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %> 2: <%@ Import Namespace="DynamicQuestions.Models" %> 3: <%@ Import Namespace="System.Linq" %> 4: <% 5: var applicableQuestions = this.ViewData["applicableQuestions"] as IEnumerable<string>; 6: var questionAttr = this.ViewData.ModelMetadata.ContainerType.GetProperty(this.ViewData.ModelMetadata.PropertyName).GetCustomAttributes(typeof(QuestionIdAttribute), true) as QuestionIdAttribute[]; 7: string questionId = null; 8: if (questionAttr.Length > 0) 9: { 10: questionId = questionAttr[0].Id; 11: } 12: if (questionId != null && applicableQuestions.Contains(questionId)) { %> 13: <div> 14: <%: Html.Label("") %> 15: <%: Html.TextBox("", this.Model)%> 16: </div> 17: <% } %> You might want to go back and read the full post in order to get the full context. MVC 3 offers a couple of new features that make this scenario more elegant to implement. The first step is to use the new [AdditionalMetadata] attribute which, so far, appears to be an under appreciated new feature of MVC 3. With this attribute, I don’t need my custom [QuestionId] attribute anymore - now I can just write my view model like this: 1: [UIHint("ScalarQuestion")] 2: [DisplayName("First Name")] 3: [AdditionalMetadata("QuestionId", "NB0021")] 4: public string FirstName { get; set; } 5:   6: [UIHint("ScalarQuestion")] 7: [DisplayName("Last Name")] 8: [AdditionalMetadata("QuestionId", "NB0022")] 9: public string LastName { get; set; } 10:   11: [UIHint("ScalarQuestion")] 12: [AdditionalMetadata("QuestionId", "NB0023")] 13: public int Age { get; set; } Thus far, the documentation seems to be pretty sparse on the AdditionalMetadata attribute. It’s buried in the Other New Features section of the MVC 3 home page and, after showing the attribute on a view model property, it just says, “This metadata is made available to any display or editor template when a product view model is rendered. It is up to you to interpret the metadata information.” But what exactly does it look like for me to “interpret the metadata information”? Well, it turns out it makes the view much easier to work with. Here is the re-implemented ScalarQuestion template updated for MVC 3 and Razor: 1: @{ 2: object questionId; 3: ViewData.ModelMetadata.AdditionalValues.TryGetValue("QuestionId", out questionId); 4: if (ViewBag.applicableQuestions.Contains((string)questionId)) { 5: <div> 6: @Html.LabelFor(m => m) 7: @Html.TextBoxFor(m => m) 8: </div> 9: } 10: } So we’ve gone from 17 lines of code (in the MVC 2 version) to about 7-8 lines of code here. The first thing to notice is that in MVC 3 we now have a property called “AdditionalValues” that hangs off of the ModelMetadata property. This is automatically populated by any [AdditionalMetadata] attributes on the property. There is no more need for me to explicitly write Reflection code to GetCustomAttributes() and then check to see if those attributes were present. I can just call TryGetValue() on the dictionary to see if they were present. Secondly, the “applicableQuestions” anonymous type that I passed in from the calling view – in MVC 3 I now have a dynamic ViewBag property where I can just “dot into” the applicableQuestions with a nicer syntax than dictionary square bracket syntax. And there’s no problems calling the Contains() method on this dynamic object because at runtime the DLR has resolved that it is a generic List<string>. At this point you might be saying that, yes the view got much nicer than the MVC 2 version, but my view model got slightly worse.  In the previous version I had a nice [QuestionId] attribute but now, with the [AdditionalMetadata] attribute, I have to type the string “QuestionId” for every single property and hope that I don’t make a typo. Well, the good news is that it’s easy to create your own attributes that can participate in the metadata’s additional values. The key is that the attribute must implement that IMetadataAware interface and populate the AdditionalValues dictionary in the OnMetadataCreated() method: 1: public class QuestionIdAttribute : Attribute, IMetadataAware 2: { 3: public string Id { get; set; } 4:   5: public QuestionIdAttribute(string id) 6: { 7: this.Id = id; 8: } 9:   10: public void OnMetadataCreated(ModelMetadata metadata) 11: { 12: metadata.AdditionalValues["QuestionId"] = this.Id; 13: } 14: } This now allows me to encapuslate my “QuestionId” string in just one place and get back to my original attribute which can be used like this: [QuestionId(“NB0021”)]. The [AdditionalMetadata] attribute is a powerful and under-appreciated new feature of MVC 3. Combined with the dynamic ViewBag property, you can do some really interesting things with your applications with less code and ceremony.

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  • Flashing your Windows Phone Dummies

    - by Martin Hinshelwood
    The rate at which vendors release new updates for the HD2 is ridiculously slow. You have to wait for Microsoft to release the new OS, then you wait for HTC to build it into a ROM, and then you have to wait up to 6 months for your operator to badly customise it for their network. Once Windows Phone 7 is released this problem should go away as Microsoft is likely to be able to update the phone over the air, but what do we do until then? I want Windows Mobile 6.5.5 now!   I’m an early adopter. If there is a new version of something then that’s the version I want. As long as you accept that you are using something on a “let the early adopter beware” and accept that there may be bugs, sometimes serious crippling bugs the go for it. Note that I won't be responsible if you end up bricking your phone, unlocking or flashing your radio or ROM can be risky. If you follow the instructions then you should be fine, I've flashed my phones (SPV, M300, M1000, M2000, M3100, TyTN, TyTN 2, HD2) hundreds of times without any problems! I have been using Windows Mobile 6.5.5 before it was called 6.5.5 and for long enough that I don’t even remember when I first started using it. I was using it on my HTC TyTN 2 before I got an HD2 a couple of months before Christmas, and the first custom ROM’s for the HD2 were a couple of months after that. I always update to the latest ROM that I like, and occasionally I go back to the stock ROM’s to have a look see, but I am always disappointed. Terms: Soft Reset: Same as pulling out the battery, but is like a reboot for your phone Hard Reset: Reinstalls the Operating system from the Image that is stored on it ROM: This is Image that is loaded onto your phone and it is used to reinstall your phone whenever you do a “hard reset”. Stock ROM: A ROM from the original vendor… So HTC Cook a ROM: Referring to Cooking a ROM is the process a ROM developer goes through to take all of the parts (OS, Drivers and Applications) that make up a running phone and compiling them into a ROM. ROM Kitchen: A place where you get an SDK and all the component parts of the phone: OD, Drivers and Application. There are usually lots of Tools for making it easier to compile and build the image. Flashing: The process of updating one of the layers of your phone with a new layer Bricked: This is what happens when flashing goes wrong. Your phone is now good for only one thing… stopping paper blowing away in a windy place. You can “cook” you own ROM using one of the many good “ROM Kitchens” or you can use a ROM built and tested by someone else. I have cooked my own ROM before, and while the tutorials are good, it is a lot of hassle. You can only Flash new ROM’s that are specifically for your phone only so find a ROM for your phone and XDA Developers is the best place to look. It has a forum based structure and you can find your phone quite easily. XDA Developer Forum Installing a new ROM does have its risks. In the past there have been stories about phones being “bricked” but I have not heard of a bricked phone for quite some years. if you follow the instructions carefully you should not have any problems. note: Most of the tools are written by people for whom English is not their first language to you will need concentrate hard to understand some of the instructions. Have you ever read a manual that was just literally translated from another language? Enough said… There are a number of layers on your phone that you will need to know about: SPL: This is the lowest level, like a BIOS on a PC and is the Operating Systems gateway to the hardware Radio: I think of this as the hardware drivers, and you will need a different Radio for CDMA than GSM networks ROM: This is like your Windows CD, but it is stored internally to the Phone. Flashing your phone consists of replacing one Image with another and then wiping your phone and automatically reinstall from the Image. Sometimes when you download an Image wither it is for a Radio or for ROM you only get a file called *.nbh. What do you do with this? Well you need an RUU application to push that Image to your phone. The RUU’s are different per phone, but there is a CustomRUU for the HD2 that will update your phone with any *.nbh placed in the same directory. Download and Instructions for CustomRUU #1 Flash HardSPL An SPL is kind of like a BIOS, and the default one has checks to make sure that you are only installing a signed ROM. This would prevent you from installing one that comes from any other source but the vendor. NOTE: Installing a HARD SPL invalidates your warranty so remember to Flash your phone with a “stock” vendor ROM before trying to send your phone in for repairs. Is the warranty reinstated when you go back to a stock ROM? I don’t know… Updating your SPL to a HardSPL effectively unlocks your phone so you can install anything you like. I would recommend the HardSPL2. Download and Instructions for HardSPL2 #2 Task29 One of the problems that has been seen on the HD2 when flashing new ROM’s is that things are left over from the old ROM. For a while the recommendation was to Flash a stock ROM first, but some clever cookies have come up with “Task29” which formats your phone first. After running this your phone will be blank and will only boot to the white HTC logo and no further. You should follow the instructions and reboot (remove battery) and hold down the “volume down” button while turning you HD2 on to enter the bootloader. From here you can run CustomRUU once the USB message appears. Download and Instructions for Task29 #2 Flash Radio You may need to play around with this one, there is no good and bad version and the latest is not always the best. You know that annoying thing when you hit “end call” on your phone and nothing happens? Well that's down to the Radio. Get this version right for you and you may even be able to make calls. From a Windows Mobile as well Download There are no instructions here, but they are the same as th ROM, but you use this *.nbh file. #3 Flash ROM If you have gotten this far then you are probably a pro by now Just download the latest ROM below and Flash to your phone. I have been really impressed by the Artemis line of ROM’s but it is no way the only choice. I like this one as the developer builds them as close to the stock ROM as possible while updating to the latest of everything. Download and Instructions for  Artemis HD2 vXX Conclusion While updating your ROM is not for the faint hearted it provides more options than the Stock ROM’s and quicker feature updates than waiting… Technorati Tags: WM6

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  • Migrating SQL Server Databases – The DBA’s Checklist (Part 1)

    - by Sadequl Hussain
    It is a fact of life: SQL Server databases change homes. They move from one instance to another, from one version to the next, from old servers to new ones.  They move around as an organisation’s data grows, applications are enhanced or new versions of the database software are released. If not anything else, servers become old and unreliable and databases eventually need to find a new home. Consider the following scenarios: 1.     A new  database application is rolled out in a production server from the development or test environment 2.     A copy of the production database needs to be installed in a test server for troubleshooting purposes 3.     A copy of the development database is regularly refreshed in a test server during the system development life cycle 4.     A SQL Server is upgraded to a newer version. This can be an in-place upgrade or a side-by-side migration 5.     One or more databases need to be moved between different instances as part of a consolidation strategy. The instances can be running the same or different version of SQL Server 6.     A database has to be restored from a backup file provided by a third party application vendor 7.     A backup of the database is restored in the same or different instance for disaster recovery 8.     A database needs to be migrated within the same instance: a.     Files are moved from direct attached storage to storage area network b.    The same database is copied under a different name for another application Migrating SQL Server database applications is a complex topic in itself. There are a number of components that can be involved: jobs, DTS or SSIS packages, logins or linked servers are only few pieces of the puzzle. However, in this article we will focus only on the central part of migration: the installation of the database itself. Unless it is an in-place upgrade, typically the database is taken from a source server and installed in a destination instance.  Most of the time, a full backup file is used for the rollout. The backup file is either provided to the DBA or the DBA takes the backup and restores it in the target server. Sometimes the database is detached from the source and the files are copied to and attached in the destination. Regardless of the method of copying, moving, refreshing, restoring or upgrading the physical database, there are a number of steps the DBA should follow before and after it has been installed in the destination. It is these post database installation steps we are going to discuss below. Some of these steps apply in almost every scenario described above while some will depend on the type of objects contained within the database.  Also, the principles hold regardless of the number of databases involved. Step 1:  Make a copy of data and log files when attaching and detaching When detaching and attaching databases, ensure you have made copies of the data and log files if the destination is running a newer version of SQL Server. This is because once attached to a newer version, the database cannot be detached and attached back to an older version. Trying to do so will give you a message like the following: Server: Msg 602, Level 21, State 50, Line 1 Could not find row in sysindexes for database ID 6, object ID 1, index ID 1. Run DBCC CHECKTABLE on sysindexes. Connection Broken If you try to backup the attached database and restore it in the source, it will still fail. Similarly, if you are restoring the database in a newer version, it cannot be backed up or detached and put back in an older version of SQL. Unlike detach and attach method though, you do not lose the backup file or the original database here. When detaching and attaching a database, it is important you keep all the log files available along with the data files. It is possible to attach a database without a log file and SQL Server can be instructed to create a new log file, however this does not work if the database was detached when the primary file group was read-only. You will need all the log files in such cases. Step 2: Change database compatibility level Once the database has been restored or attached to a newer version of SQL Server, change the database compatibility level to reflect the newer version unless there is a compelling reason not to do so. When attaching or restoring from a previous version of SQL, the database retains the older version’s compatibility level.  The only time you would want to keep a database with an older compatibility level is when the code within your database is no longer supported by SQL Server. For example, outer joins with *= or the =* operators were still possible in SQL 2000 (with a warning message), but not in SQL 2005 anymore. If your stored procedures or triggers are using this form of join, you would want to keep the database with an older compatibility level.  For a list of compatibility issues between older and newer versions of SQL Server databases, refer to the Books Online under the sp_dbcmptlevel topic. Application developers and architects can help you in deciding whether you should change the compatibility level or not. You can always change the compatibility mode from the newest to an older version if necessary. To change the compatibility level, you can either use the database’s property from the SQL Server Management Studio or use the sp_dbcmptlevel stored procedure.   Bear in mind that you cannot run the built-in reports for databases from SQL Server Management Studio if you keep the database with an older compatibility level. The following figure shows the error message I received when trying to run the “Disk Usage by Top Tables” report against a database. This database was hosted in a SQL Server 2005 system and still had a compatibility mode 80 (SQL 2000).     Continues…

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  • C#/.NET Little Pitfalls: The Dangers of Casting Boxed Values

    - by James Michael Hare
    Starting a new series to parallel the Little Wonders series.  In this series, I will examine some of the small pitfalls that can occasionally trip up developers. Introduction: Of Casts and Conversions What happens when we try to assign from an int and a double and vice-versa? 1: double pi = 3.14; 2: int theAnswer = 42; 3:  4: // implicit widening conversion, compiles! 5: double doubleAnswer = theAnswer; 6:  7: // implicit narrowing conversion, compiler error! 8: int intPi = pi; As you can see from the comments above, a conversion from a value type where there is no potential data loss is can be done with an implicit conversion.  However, when converting from one value type to another may result in a loss of data, you must make the conversion explicit so the compiler knows you accept this risk.  That is why the conversion from double to int will not compile with an implicit conversion, we can make the conversion explicit by adding a cast: 1: // explicit narrowing conversion using a cast, compiler 2: // succeeds, but results may have data loss: 3: int intPi = (int)pi; So for value types, the conversions (implicit and explicit) both convert the original value to a new value of the given type.  With widening and narrowing references, however, this is not the case.  Converting reference types is a bit different from converting value types.  First of all when you perform a widening or narrowing you don’t really convert the instance of the object, you just convert the reference itself to the wider or narrower reference type, but both the original and new reference type both refer back to the same object. Secondly, widening and narrowing for reference types refers the going down and up the class hierarchy instead of referring to precision as in value types.  That is, a narrowing conversion for a reference type means you are going down the class hierarchy (for example from Shape to Square) whereas a widening conversion means you are going up the class hierarchy (from Square to Shape).  1: var square = new Square(); 2:  3: // implicitly convers because all squares are shapes 4: // (that is, all subclasses can be referenced by a superclass reference) 5: Shape myShape = square; 6:  7: // implicit conversion not possible, not all shapes are squares! 8: // (that is, not all superclasses can be referenced by a subclass reference) 9: Square mySquare = (Square) myShape; So we had to cast the Shape back to Square because at that point the compiler has no way of knowing until runtime whether the Shape in question is truly a Square.  But, because the compiler knows that it’s possible for a Shape to be a Square, it will compile.  However, if the object referenced by myShape is not truly a Square at runtime, you will get an invalid cast exception. Of course, there are other forms of conversions as well such as user-specified conversions and helper class conversions which are beyond the scope of this post.  The main thing we want to focus on is this seemingly innocuous casting method of widening and narrowing conversions that we come to depend on every day and, in some cases, can bite us if we don’t fully understand what is going on!  The Pitfall: Conversions on Boxed Value Types Can Fail What if you saw the following code and – knowing nothing else – you were asked if it was legal or not, what would you think: 1: // assuming x is defined above this and this 2: // assignment is syntactically legal. 3: x = 3.14; 4:  5: // convert 3.14 to int. 6: int truncated = (int)x; You may think that since x is obviously a double (can’t be a float) because 3.14 is a double literal, but this is inaccurate.  Our x could also be dynamic and this would work as well, or there could be user-defined conversions in play.  But there is another, even simpler option that can often bite us: what if x is object? 1: object x; 2:  3: x = 3.14; 4:  5: int truncated = (int) x; On the surface, this seems fine.  We have a double and we place it into an object which can be done implicitly through boxing (no cast) because all types inherit from object.  Then we cast it to int.  This theoretically should be possible because we know we can explicitly convert a double to an int through a conversion process which involves truncation. But here’s the pitfall: when casting an object to another type, we are casting a reference type, not a value type!  This means that it will attempt to see at runtime if the value boxed and referred to by x is of type int or derived from type int.  Since it obviously isn’t (it’s a double after all) we get an invalid cast exception! Now, you may say this looks awfully contrived, but in truth we can run into this a lot if we’re not careful.  Consider using an IDataReader to read from a database, and then attempting to select a result row of a particular column type: 1: using (var connection = new SqlConnection("some connection string")) 2: using (var command = new SqlCommand("select * from employee", connection)) 3: using (var reader = command.ExecuteReader()) 4: { 5: while (reader.Read()) 6: { 7: // if the salary is not an int32 in the SQL database, this is an error! 8: // doesn't matter if short, long, double, float, reader [] returns object! 9: total += (int) reader["annual_salary"]; 10: } 11: } Notice that since the reader indexer returns object, if we attempt to convert using a cast to a type, we have to make darn sure we use the true, actual type or this will fail!  If the SQL database column is a double, float, short, etc this will fail at runtime with an invalid cast exception because it attempts to convert the object reference! So, how do you get around this?  There are two ways, you could first cast the object to its actual type (double), and then do a narrowing cast to on the value to int.  Or you could use a helper class like Convert which analyzes the actual run-time type and will perform a conversion as long as the type implements IConvertible. 1: object x; 2:  3: x = 3.14; 4:  5: // if you want to cast, must cast out of object to double, then 6: // cast convert. 7: int truncated = (int)(double) x; 8:  9: // or you can call a helper class like Convert which examines runtime 10: // type of the value being converted 11: int anotherTruncated = Convert.ToInt32(x); Summary You should always be careful when performing a conversion cast from values boxed in object that you are actually casting to the true type (or a sub-type). Since casting from object is a widening of the reference, be careful that you either know the exact, explicit type you expect to be held in the object, or instead avoid the cast and use a helper class to perform a safe conversion to the type you desire. Technorati Tags: C#,.NET,Pitfalls,Little Pitfalls,BlackRabbitCoder

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  • JMaghreb 2012 Trip Report

    - by arungupta
    JMaghreb is the inaugural Java conference organized by Morocco JUG. It is the biggest Java conference in Maghreb (5 countries in North West Africa). Oracle was the exclusive platinum sponsor with several others. The registrations had to be closed at 1412 for the free conference and several folks were already on the waiting list. Rabat with 531 registrations and Casablanca with 426 were the top cities. Some statistics ... 850+ attendees over 2 days, 500+ every day 30 sessions were delivered by 18 speakers from 10 different countries 10 sessions in French and 20 in English 6 of the speakers spoke at JavaOne 2012 8 will be at Devoxx Attendees from 5 different countries and 57 cities in Morocco 40.9% qualified them as professional and rest as students Topics ranged from HTML5, Java EE 7, ADF, JavaFX, MySQL, JCP, Vaadin, Android, Community, JCP Java EE 6 hands-on lab was sold out within 7 minutes and JavaFX in 12 minutes I gave the keynote along with Simon Ritter which was basically a recap of the Strategy and Technical keynotes presented at JavaOne 2012. An informal survey during the keynote showed the following numbers: 25% using NetBeans, 90% on Eclipse, 3 on JDeveloper, 1 on IntelliJ About 10 subscribers to free online Java magazine. This digital magazine is a comprehensive source of information for everything Java - subscribe for free!! About 10-15% using Java SE 7. Download JDK 7 and get started today! Even JDK 8 builds have been available for a while now. My second talk explained the core concepts of WebSocket and how JSR 356 is providing a standard API to build WebSocket-driven applications in Java EE 7. TOTD #183 explains how you can easily get started with WebSocket in GlassFish 4. The complete slide deck is available: Next day started with a community keynote by Sonya Barry. Some of us live the life of JCP, JSR, EG, EC, RI, etc every day, but not every body is. To address that, Sonya prepared an excellent introductory presentation providing an explanation of these terms and how java.net infrastructure supports Java development. The registration for the lab showed there is a definite demand for these technologies in this part of the world. I delivered the Java EE 6 hands-on lab to a packed room of about 120 attendees. Most of the attendees were able to progress and follow the lab instructions. Some of the attendees did not have a laptop but were taking extensive notes on paper notepads. Several attendees were already using Java EE 6 in their projects and typically they are the ones asking deep dive questions. Also gave out three copies of my recently released Java EE 6 Pocket Guide and new GlassFish t-shirts. Definitely feels happy to coach ~120 more Java developers learn standards-based enterprise Java programming. I also participated in a JCP BoF along with Werner, Sonya, and Badr. Adotp-a-JSR, java.net infrastructure, how to file a JSR, what is an RI, and other similar topics were discussed in a candid manner. You can follow @JMaghrebConf or check out their facebook page. java.net published a timely conversation with Badr El Houari - the fearless leader of the Morocco JUG team. Did you know that Morocco JUG stood for JCP EC elections (ADD LINK) ? Even though they did not get elected but did fairly well. Now some sample tweets from #JMaghreb ... #JMaghreb is over. Impressive for a first edition! Thanks @badrelhouari and all the @MoroccoJUG team ! Since you @speakjava : System.out.println("Thank you so much dear Tech Evangelist ! The JavaFX was pretty amazing !!! "); #JMaghreb @YounesVendetta @arungupta @JMaghrebConf Right ! hope he will be back to morocco again and again .. :) @Alji_ @arungupta @JMaghrebConf That dude is a genius ;) Put it on your wall :p @arungupta rocking Java EE 6 at @JMaghrebConf #Java #JavaEE #JMaghreb http://t.co/isl0Iq5p @sonyabarry you are an awesome speaker ;-) #JMaghreb rich more than 550 attendees in day one. Expecting more tomorrow! ongratulations @badrelhouari the organisation was great! The talks were pretty interesting, and the turnout was surprising at #JMaghreb! #JMaghreb is truly awesome... The speakers are unbelievable ! #JavaFX... Just amazing #JMaghreb Charmed by the talk about #javaFX ( nodes architecture, MVC, Lazy loading, binding... ) gotta start using it intead of SWT. #JMaghreb JavaFX is killing JFreeChart. It supports Charts a lot of kind of them ... #JMaghreb The british man is back #JMaghreb I do like him!! #JMaghreb @arungupta rocking @JMaghrebConf. pic.twitter.com/CNohA3PE @arungupta Great talk about the future of Java EE (JEE 7 & JEE 8) Thank you. #JMaghreb JEE7 more mooore power , leeess less code !! #JMaghreb They are simplifying the existing API for Java Message Service 2.0 #JMaghreb good to know , the more the code is simplified the better ! The Glassdoor guy #arungupta is doing it RIGHT ! #JMaghreb Great presentation of The Future of the Java Platform: Java EE 7, Java SE 8 & Beyond #jMaghreb @arungupta is a great Guy apparently #JMaghreb On a personal front, the hotel (Soiftel Jardin des Roses) was pretty nice and the location was perfect. There was a 1.8 mile loop dirt trail right next to it so I managed to squeeze some runs before my upcoming marathon. Also enjoyed some great Moroccan cuisine - Couscous, Tajine, mint tea, and moroccan salad. Visit to Kasbah of the Udayas, Hassan II (one of the tallest mosque in the world), and eating in a restaurant in a kasbah are some of the exciting local experiences. Now some pictures from the event (and around the city) ... And the complete album: Many thanks to Badr, Faisal, and rest of the team for organizing a great conference. They are already thinking about how to improve the content, logisitics, and flow for the next year. I'm certainly looking forward to JMaghreb 2.0 :-)

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  • Highlight Row in GridView with Colored Columns

    - by Vincent Maverick Durano
    I wrote a blog post a while back before here that demonstrate how to highlight a GridView row on mouseover and as you can see its very easy to highlight rows in GridView. One of my colleague uses the same technique for implemeting gridview row highlighting but the problem is that if a Column has background color on it that cell will not be highlighted anymore. To make it more clear then let's build up a sample application. ASPX:   1: <asp:GridView runat="server" id="GridView1" onrowcreated="GridView1_RowCreated" 2: onrowdatabound="GridView1_RowDataBound"> 3: </asp:GridView>   CODE BEHIND:   1: private DataTable FillData() { 2:   3: DataTable dt = new DataTable(); 4: DataRow dr = null; 5:   6: //Create DataTable columns 7: dt.Columns.Add(new DataColumn("RowNumber", typeof(string))); 8: dt.Columns.Add(new DataColumn("Col1", typeof(string))); 9: dt.Columns.Add(new DataColumn("Col2", typeof(string))); 10: dt.Columns.Add(new DataColumn("Col3", typeof(string))); 11:   12: //Create Row for each columns 13: dr = dt.NewRow(); 14: dr["RowNumber"] = 1; 15: dr["Col1"] = "A"; 16: dr["Col2"] = "B"; 17: dr["Col3"] = "C"; 18: dt.Rows.Add(dr); 19:   20: dr = dt.NewRow(); 21: dr["RowNumber"] = 2; 22: dr["Col1"] = "AA"; 23: dr["Col2"] = "BB"; 24: dr["Col3"] = "CC"; 25: dt.Rows.Add(dr); 26:   27: dr = dt.NewRow(); 28: dr["RowNumber"] = 3; 29: dr["Col1"] = "A"; 30: dr["Col2"] = "B"; 31: dr["Col3"] = "CC"; 32: dt.Rows.Add(dr); 33:   34: dr = dt.NewRow(); 35: dr["RowNumber"] = 4; 36: dr["Col1"] = "A"; 37: dr["Col2"] = "B"; 38: dr["Col3"] = "CC"; 39: dt.Rows.Add(dr); 40:   41: dr = dt.NewRow(); 42: dr["RowNumber"] = 5; 43: dr["Col1"] = "A"; 44: dr["Col2"] = "B"; 45: dr["Col3"] = "CC"; 46: dt.Rows.Add(dr); 47:   48: return dt; 49: } 50:   51: protected void Page_Load(object sender, EventArgs e) { 52: if (!IsPostBack) { 53: GridView1.DataSource = FillData(); 54: GridView1.DataBind(); 55: } 56: }   As you can see there's nothing fancy in the code above. It just contain a method that fills a DataTable with a dummy data on it. Now here's the code for row highlighting:   1: protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e) { 2: //Set Background Color for Columns 1 and 3 3: e.Row.Cells[1].BackColor = System.Drawing.Color.Beige; 4: e.Row.Cells[3].BackColor = System.Drawing.Color.Red; 5:   6: //Attach onmouseover and onmouseout for row highlighting 7: e.Row.Attributes.Add("onmouseover", "this.style.backgroundColor='Blue'"); 8: e.Row.Attributes.Add("onmouseout", "this.style.backgroundColor=''"); 9: }   Running the code above will show something like this in the browser: On initial load: On mouseover of GridView row:   Noticed that Col1 and Col3 are not highlighted. Why? the reason is that Col1 and Col3 cells has background color set on it and we only highlight the rows (TR) and not the columns (TD) that's why on mouseover only the rows will be highlighted. To fix the issue we will create a javascript method that would remove the background color of the columns when highlighting a row and on mouseout set back the original color that is set on Col1 and Col3. Here are the codes below: JavaScript   1: <script type="text/javascript"> 2: function HighLightRow(rowIndex, colIndex,colIndex2, flag) { 3: var gv = document.getElementById("<%= GridView1.ClientID %>"); 4: var selRow = gv.rows[rowIndex]; 5: if (rowIndex > 0) { 6: if (flag == "sel") { 7: gv.rows[rowIndex].style.backgroundColor = 'Blue'; 8: gv.rows[rowIndex].style.color = "White"; 9: gv.rows[rowIndex].cells[colIndex].style.backgroundColor = ''; 10: gv.rows[rowIndex].cells[colIndex2].style.backgroundColor = ''; 11: } 12: else { 13: gv.rows[rowIndex].style.backgroundColor = ''; 14: gv.rows[rowIndex].style.color = "Black"; 15: gv.rows[rowIndex].cells[colIndex].style.backgroundColor = 'Beige'; 16: gv.rows[rowIndex].cells[colIndex2].style.backgroundColor = 'Red'; 17: } 18: } 19: } 20: </script>   The HighLightRow method is a javascript function that accepts four (4) parameters which are the rowIndex,colIndex,colIndex2 and the flag. The rowIndex is the current row index of the selected row in GridView. The colIndex is the index of Col1 and colIndex2 is the index of col3. We are passing these index because these columns has background color on it and we need to toggle its backgroundcolor when highlighting the row in GridView. Finally the flag is something that would determine if its selected or not. Now here's the code for calling the JavaScript function above.     1: protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e) { 2:   3: //Set Background Color for Columns 1 and 3 4: e.Row.Cells[1].BackColor = System.Drawing.Color.Beige; 5: e.Row.Cells[3].BackColor = System.Drawing.Color.Red; 6:   7: //Attach onmouseover and onmouseout for row highlighting 8: //and call the HighLightRow method with the required parameters 9: int index = e.Row.RowIndex + 1; 10: e.Row.Attributes.Add("onmouseover", "HighLightRow(" + index + "," + 1 + "," + 3 + ",'sel')"); 11: e.Row.Attributes.Add("onmouseout", "HighLightRow(" + index + "," + 1 + "," + 3 + ",'dsel')"); 12: 13: }   Running the code above will display something like this: On initial load:   On mouseover of GridView row:   That's it! I hope someone find this post useful!

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  • bluetooth not working on Ubuntu 13.10

    - by iacopo
    I upgrated ubuntu from 13.4 to 13.10 and my bluetooth stopped working. When I open bluetooth I'm able to put it ON but the visibility doesn't show anything and didn't detect any device. when I: dmesg | grep Blue [ 2.046249] usb 3-1: Product: Bluetooth V2.0 Dongle [ 2.046252] usb 3-1: Manufacturer: Bluetooth v2.0 [ 15.255710] Bluetooth: Core ver 2.16 [ 15.255748] Bluetooth: HCI device and connection manager initialized [ 15.255759] Bluetooth: HCI socket layer initialized [ 15.255765] Bluetooth: L2CAP socket layer initialized [ 15.255776] Bluetooth: SCO socket layer initialized [ 20.110379] Bluetooth: BNEP (Ethernet Emulation) ver 1.3 [ 20.110386] Bluetooth: BNEP filters: protocol multicast [ 20.110400] Bluetooth: BNEP socket layer initialized [ 20.120635] Bluetooth: RFCOMM TTY layer initialized [ 20.120656] Bluetooth: RFCOMM socket layer initialized [ 20.120660] Bluetooth: RFCOMM ver 1.11 when I digit: lsusb Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 002 Device 002: ID 0bc2:2300 Seagate RSS LLC Expansion Portable Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 006 Device 002: ID 0e6a:6001 Megawin Technology Co., Ltd GEMBIRD Flexible keyboard KB-109F-B-DE Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 005 Device 002: ID 13ee:0001 MosArt Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 003 Device 002: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode) Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub when I: hciconfig -a hci0: Type: BR/EDR Bus: USB BD Address: 00:1B:10:00:2A:EC ACL MTU: 1017:8 SCO MTU: 64:0 DOWN RX bytes:457 acl:0 sco:0 events:16 errors:0 TX bytes:68 acl:0 sco:0 commands:16 errors:0 Features: 0xff 0xff 0x8d 0xfe 0x9b 0xf9 0x00 0x80 Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 Link policy: Link mode: SLAVE ACCEPT when I digit: rfkill list 0: phy0: Wireless LAN Soft blocked: yes Hard blocked: no 1: hci0: Bluetooth Soft blocked: no Hard blocked: no when I digit: sudo gedit /etc/bluetooth/main.conf [General] # List of plugins that should not be loaded on bluetoothd startup #DisablePlugins = network,input # Default adaper name # %h - substituted for hostname # %d - substituted for adapter id Name = %h-%d # Default device class. Only the major and minor device class bits are # considered. Class = 0x000100 # How long to stay in discoverable mode before going back to non-discoverable # The value is in seconds. Default is 180, i.e. 3 minutes. # 0 = disable timer, i.e. stay discoverable forever DiscoverableTimeout = 0 # How long to stay in pairable mode before going back to non-discoverable # The value is in seconds. Default is 0. # 0 = disable timer, i.e. stay pairable forever PairableTimeout = 0 # Use some other page timeout than the controller default one # which is 16384 (10 seconds). PageTimeout = 8192 # Automatic connection for bonded devices driven by platform/user events. # If a platform plugin uses this mechanism, automatic connections will be # enabled during the interval defined below. Initially, this feature # intends to be used to establish connections to ATT channels. AutoConnectTimeout = 60 # What value should be assumed for the adapter Powered property when # SetProperty(Powered, ...) hasn't been called yet. Defaults to true InitiallyPowered = true # Remember the previously stored Powered state when initializing adapters RememberPowered = false # Use vendor id source (assigner), vendor, product and version information for # DID profile support. The values are separated by ":" and assigner, VID, PID # and version. # Possible vendor id source values: bluetooth, usb (defaults to usb) #DeviceID = bluetooth:1234:5678:abcd # Do reverse service discovery for previously unknown devices that connect to # us. This option is really only needed for qualification since the BITE tester # doesn't like us doing reverse SDP for some test cases (though there could in # theory be other useful purposes for this too). Defaults to true. ReverseServiceDiscovery = true # Enable name resolving after inquiry. Set it to 'false' if you don't need # remote devices name and want shorter discovery cycle. Defaults to 'true'. NameResolving = true # Enable runtime persistency of debug link keys. Default is false which # makes debug link keys valid only for the duration of the connection # that they were created for. DebugKeys = false # Enable the GATT functionality. Default is false EnableGatt = false when I digit: dmesg | grep Bluetooth [ 2.013041] usb 3-1: Product: Bluetooth V2.0 Dongle [ 2.013049] usb 3-1: Manufacturer: Bluetooth v2.0 [ 13.798293] Bluetooth: Core ver 2.16 [ 13.798338] Bluetooth: HCI device and connection manager initialized [ 13.798352] Bluetooth: HCI socket layer initialized [ 13.798357] Bluetooth: L2CAP socket layer initialized [ 13.798368] Bluetooth: SCO socket layer initialized [ 20.184162] Bluetooth: BNEP (Ethernet Emulation) ver 1.3 [ 20.184173] Bluetooth: BNEP filters: protocol multicast [ 20.184197] Bluetooth: BNEP socket layer initialized [ 20.238947] Bluetooth: RFCOMM TTY layer initialized [ 20.238983] Bluetooth: RFCOMM socket layer initialized [ 20.239018] Bluetooth: RFCOMM ver 1.11 When I digit: uname -a Linux casa-desktop 3.11.0-13-generic #20-Ubuntu SMP Wed Oct 23 07:38:26 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux When I digit: lsmod Module Size Used by parport_pc 32701 0 rfcomm 69070 4 bnep 19564 2 ppdev 17671 0 ip6t_REJECT 12910 1 xt_hl 12521 6 ip6t_rt 13507 3 nf_conntrack_ipv6 18938 9 nf_defrag_ipv6 34616 1 nf_conntrack_ipv6 ipt_REJECT 12541 1 xt_LOG 17718 8 xt_limit 12711 11 xt_tcpudp 12884 32 xt_addrtype 12635 4 nf_conntrack_ipv4 15012 9 nf_defrag_ipv4 12729 1 nf_conntrack_ipv4 xt_conntrack 12760 18 ip6table_filter 12815 1 ip6_tables 27025 1 ip6table_filter nf_conntrack_netbios_ns 12665 0 nf_conntrack_broadcast 12589 1 nf_conntrack_netbios_ns nf_nat_ftp 12741 0 nf_nat 26653 1 nf_nat_ftp kvm_amd 59958 0 nf_conntrack_ftp 18608 1 nf_nat_ftp kvm 431315 1 kvm_amd nf_conntrack 91736 8 nf_nat_ftp,nf_conntrack_netbios_ns,nf_nat,xt_conntrack,nf_conntrack_broadcast,nf_conntrack_ftp,nf_conntrack_ipv4,nf_conntrack_ipv6 iptable_filter 12810 1 crct10dif_pclmul 14289 0 crc32_pclmul 13113 0 ip_tables 27239 1 iptable_filter snd_hda_codec_realtek 55704 1 ghash_clmulni_intel 13259 0 aesni_intel 55624 0 aes_x86_64 17131 1 aesni_intel snd_hda_codec_hdmi 41117 1 x_tables 34059 13 ip6table_filter,xt_hl,ip_tables,xt_tcpudp,xt_limit,xt_conntrack,xt_LOG,iptable_filter,ip6t_rt,ipt_REJECT,ip6_tables,xt_addrtype,ip6t_REJECT lrw 13257 1 aesni_intel snd_hda_intel 48171 5 gf128mul 14951 1 lrw glue_helper 13990 1 aesni_intel ablk_helper 13597 1 aesni_intel joydev 17377 0 cryptd 20329 3 ghash_clmulni_intel,aesni_intel,ablk_helper snd_hda_codec 188738 3 snd_hda_codec_realtek,snd_hda_codec_hdmi,snd_hda_intel arc4 12608 2 snd_hwdep 13602 1 snd_hda_codec rt2800pci 18690 0 snd_pcm 102033 3 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel radeon 1402449 3 rt2800lib 79963 1 rt2800pci btusb 28267 0 rt2x00pci 13287 1 rt2800pci rt2x00mmio 13603 1 rt2800pci snd_page_alloc 18710 2 snd_pcm,snd_hda_intel rt2x00lib 55238 4 rt2x00pci,rt2800lib,rt2800pci,rt2x00mmio snd_seq_midi 13324 0 mac80211 596969 3 rt2x00lib,rt2x00pci,rt2800lib snd_seq_midi_event 14899 1 snd_seq_midi ttm 83995 1 radeon snd_rawmidi 30095 1 snd_seq_midi cfg80211 479757 2 mac80211,rt2x00lib drm_kms_helper 52651 1 radeon snd_seq 61560 2 snd_seq_midi_event,snd_seq_midi bluetooth 371880 12 bnep,btusb,rfcomm microcode 23518 0 eeprom_93cx6 13344 1 rt2800pci snd_seq_device 14497 3 snd_seq,snd_rawmidi,snd_seq_midi crc_ccitt 12707 1 rt2800lib snd_timer 29433 2 snd_pcm,snd_seq snd 69141 21 snd_hda_codec_realtek,snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_pcm,snd_seq,snd_rawmidi,snd_hda_codec,snd_hda_intel,snd_seq_device,snd_seq_midi psmouse 97626 0 drm 296739 5 ttm,drm_kms_helper,radeon k10temp 13126 0 soundcore 12680 1 snd serio_raw 13413 0 i2c_algo_bit 13413 1 radeon i2c_piix4 22106 0 video 19318 0 mac_hid 13205 0 lp 17759 0 parport 42299 3 lp,ppdev,parport_pc hid_generic 12548 0 usbhid 53014 0 hid 105818 2 hid_generic,usbhid pata_acpi 13038 0 usb_storage 62062 1 r8169 67341 0 sdhci_pci 18985 0 sdhci 42630 1 sdhci_pci mii 13934 1 r8169 pata_atiixp 13242 0 ohci_pci 13561 0 ahci 25819 2 libahci 31898 1 ahci Someone can help me?

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  • The Proper Use of the VM Role in Windows Azure

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

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  • Using SQL Source Control with Fortress or Vault &ndash; Part 2

    - by AjarnMark
    In Part 1, I started talking about using Red-Gate’s newest version of SQL Source Control and how I really like it as a viable method to source control your database development.  It looks like this is going to turn into a little series where I will explain how we have done things in the past, and how life is different with SQL Source Control.  I will also explain some of my philosophy and methodology around deployment with these tools.  But for now, let’s talk about some of the good and the bad of the tool itself. More Kudos and Features I mentioned previously how impressed I was with the responsiveness of Red-Gate’s team.  I have been having an ongoing email conversation with Gyorgy Pocsi, and as I have run into problems or requested things behave a little differently, it has not been more than a day or two before a new Build is ready for me to download and test.  Quite impressive! I’m sure much of the requests I put in were already in the plans, so I can’t really take credit for them, but throughout this conversation, Red-Gate has implemented several features that were not in the first Early Access version.  Those include: Honoring the Fortress configuration option to require Work Item (Bug) IDs on check-ins. Adding the check-in comment text as a comment to the Work Item. Adding the list of checked-in files, along with the Fortress links for automatic History and DIFF view Updating the status of a Work Item on check-in (e.g. setting the item to Complete or, in our case “Dev-Complete”) Support for the Fortress 2.0 API, and not just the Vault Pro 5.1 API.  (See later notes regarding support for Fortress 2.0). These were all features that I felt we really needed to have in-place before I could honestly consider converting my team to using SQL Source Control on a regular basis.  Now that I have those, my only excuse is not wanting to switch boats on the team mid-stream.  So when we wrap up our current release in a few weeks, we will make the jump.  In the meantime, I will continue to bang on it to make sure it is stable.  It passed one test for stability when I did a test load of one of our larger database schemas into Fortress with SQL Source Control.  That database has about 150 tables, 200 User-Defined Functions and nearly 900 Stored Procedures.  The initial load to source control went smoothly and took just a brief amount of time. Warnings Remember that this IS still in pre-release stage and while I have not had any problems after that first hiccup I wrote about last time, you still need to treat it with a healthy respect.  As I understand it, the RTM is targeted for February.  There are a couple more features that I hope make it into the final release version, but if not, they’ll probably be coming soon thereafter.  Those are: A Browse feature to let me lookup the Work Item ID instead of having to remember it or look back in my Item details.  This is just a matter of convenience. I normally have my Work Item list open anyway, so I can easily look it up, but hey, why not make it even easier. A multi-line comment area.  The current space for writing check-in comments is a single-line text box.  I would like to have a multi-line space as I sometimes write lengthy commentary.  But I recognize that it is a struggle to get most developers to put in more than the word “fixed” as their comment, so this meets the need of the majority as-is, and it’s not a show-stopper for us. Merge.  SQL Source Control currently does not have a Merge feature.  If two or more people make changes to the same database object, you will get a warning of the conflict and have to choose which one wins (and then manually edit to include the others’ changes).  I think it unlikely you will run into actual conflicts in Stored Procedures and Functions, but you might with Views or Tables.  This will be nice to have, but I’m not losing any sleep over it.  And I have multiple tools at my disposal to do merges manually, so really not a show-stopper for us. Automation has its limits.  As cool as this automation is, it has its limits and there are some changes that you will be better off scripting yourself.  For example, if you are refactoring table definitions, and want to change a column name, you can write that as a quick sp_rename command and preserve the data within that column.  But because this tool is looking just at a before and after picture, it cannot tell that you just renamed a column.  To the tool, it looks like you dropped one column and added another.  This is not a knock against Red-Gate.  All automated scripting tools have this issue, unless the are actively monitoring your every step to know exactly what you are doing.  This means that when you go to Deploy your changes, SQL Compare will script the change as a column drop and add, or will attempt to rebuild the entire table.  Unfortunately, neither of these approaches will preserve the existing data in that column the way an sp_rename will, and so you are better off scripting that change yourself.  Thankfully, SQL Compare will produce warnings about the potential loss of data before it does the actual synchronization and give you a chance to intercept the script and do it yourself. Also, please note that the current official word is that SQL Source Control supports Vault Professional 5.1 and later.  Vault Professional is the new name for what was previously known as Fortress.  (You can read about the name change on SourceGear’s site.)  The last version of Fortress was 2.x, and the API for Fortress 2.x is different from the API for Vault Pro.  At my company, we are currently running Fortress 2.0, with plans to upgrade to Vault Pro early next year.  Gyorgy was able to come up with a work-around for me to be able to use SQL Source Control with Fortress 2.0, even though it is not officially supported.  If you are using Fortress 2.0 and want to use SQL Source Control, be aware that this is not officially supported, but it is working for us, and you can probably get the work-around instructions from Red-Gate if you’re really, really nice to them. Upcoming Topics Some of the other topics I will likely cover in this series over the next few weeks are: How we used to do source control back in the old days (a few weeks ago) before SQL Source Control was available to Vault users What happens when you restore a database that is linked to source control Handling multiple development branches of source code Concurrent Development practices and handling Conflicts Deployment Tips and Best Practices A recap after using the tool for a while

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  • Using Radio Button in GridView with Validation

    - by Vincent Maverick Durano
    A developer is asking how to select one radio button at a time if the radio button is inside the GridView.  As you may know setting the group name attribute of radio button will not work if the radio button is located within a Data Representation control like GridView. This because the radio button inside the gridview bahaves differentely. Since a gridview is rendered as table element , at run time it will assign different "name" to each radio button. Hence you are able to select multiple rows. In this post I'm going to demonstrate how select one radio button at a time in gridview and add a simple validation on it. To get started let's go ahead and fire up visual studio and the create a new web application / website project. Add a WebForm and then add gridview. The mark up would look something like this: <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" > <Columns> <asp:TemplateField> <ItemTemplate> <asp:RadioButton ID="rb" runat="server" /> </ItemTemplate> </asp:TemplateField> <asp:BoundField DataField="RowNumber" HeaderText="Row Number" /> <asp:BoundField DataField="Col1" HeaderText="First Column" /> <asp:BoundField DataField="Col2" HeaderText="Second Column" /> </Columns> </asp:GridView> Noticed that I've added a templatefield column so that we can add the radio button there. Also I have set up some BoundField columns and set the DataFields as RowNumber, Col1 and Col2. These columns are just dummy columns and i used it for the simplicity of this example. Now where these columns came from? These columns are created by hand at the code behind file of the ASPX. Here's the code below: private DataTable FillData() { DataTable dt = new DataTable(); DataRow dr = null; //Create DataTable columns dt.Columns.Add(new DataColumn("RowNumber", typeof(string))); dt.Columns.Add(new DataColumn("Col1", typeof(string))); dt.Columns.Add(new DataColumn("Col2", typeof(string))); //Create Row for each columns dr = dt.NewRow(); dr["RowNumber"] = 1; dr["Col1"] = "A"; dr["Col2"] = "B"; dt.Rows.Add(dr); dr = dt.NewRow(); dr["RowNumber"] = 2; dr["Col1"] = "AA"; dr["Col2"] = "BB"; dt.Rows.Add(dr); dr = dt.NewRow(); dr["RowNumber"] = 3; dr["Col1"] = "A"; dr["Col2"] = "B"; dt.Rows.Add(dr); dr = dt.NewRow(); dr["RowNumber"] = 4; dr["Col1"] = "A"; dr["Col2"] = "B"; dt.Rows.Add(dr); dr = dt.NewRow(); dr["RowNumber"] = 5; dr["Col1"] = "A"; dr["Col2"] = "B"; dt.Rows.Add(dr); return dt; } And here's the code for binding the GridView with the dummy data above. protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { GridView1.DataSource = FillData(); GridView1.DataBind(); } } Okay we have now a GridView data with a radio button on each row. Now lets go ahead and switch back to ASPX mark up. In this example I'm going to use a JavaScript for validating the radio button to select one radio button at a time. Here's the javascript code below: function CheckOtherIsCheckedByGVID(rb) { var isChecked = rb.checked; var row = rb.parentNode.parentNode; if (isChecked) { row.style.backgroundColor = '#B6C4DE'; row.style.color = 'black'; } var currentRdbID = rb.id; parent = document.getElementById("<%= GridView1.ClientID %>"); var items = parent.getElementsByTagName('input'); for (i = 0; i < items.length; i++) { if (items[i].id != currentRdbID && items[i].type == "radio") { if (items[i].checked) { items[i].checked = false; items[i].parentNode.parentNode.style.backgroundColor = 'white'; items[i].parentNode.parentNode.style.color = '#696969'; } } } } The function above sets the row of the current selected radio button's style to determine that the row is selected and then loops through the radio buttons in the gridview and then de-select the previous selected radio button and set the row style back to its default. You can then call the javascript function above at onlick event of radio button like below: <asp:RadioButton ID="rb" runat="server" onclick="javascript:CheckOtherIsCheckedByGVID(this);" /> Here's the output below: On Load: After Selecting a Radio Button: As you have noticed, on initial load there's no default selected radio in the GridView. Now let's add a simple validation for that. We will basically display an error message if a user clicks a button that triggers a postback without selecting  a radio button in the GridView. Here's the javascript for the validation: function ValidateRadioButton(sender, args) { var gv = document.getElementById("<%= GridView1.ClientID %>"); var items = gv.getElementsByTagName('input'); for (var i = 0; i < items.length ; i++) { if (items[i].type == "radio") { if (items[i].checked) { args.IsValid = true; return; } else { args.IsValid = false; } } } } The function above loops through the rows in gridview and find all the radio buttons within it. It will then check each radio button checked property. If a radio is checked then set IsValid to true else set it to false.  The reason why I'm using IsValid is because I'm using the ASP validator control for validation. Now add the following mark up below under the GridView declaration: <br /> <asp:Label ID="lblMessage" runat="server" /> <br /> <asp:Button ID="btn" runat="server" Text="POST" onclick="btn_Click" ValidationGroup="GroupA" /> <asp:CustomValidator ID="CustomValidator1" runat="server" ErrorMessage="Please select row in the grid." ClientValidationFunction="ValidateRadioButton" ValidationGroup="GroupA" style="display:none"></asp:CustomValidator> <asp:ValidationSummary ID="ValidationSummary1" runat="server" ValidationGroup="GroupA" HeaderText="Error List:" DisplayMode="BulletList" ForeColor="Red" /> And then at Button Click event add this simple code below just to test if  the validation works: protected void btn_Click(object sender, EventArgs e) { lblMessage.Text = "Postback at: " + DateTime.Now.ToString("hh:mm:ss tt"); } Here's the output below that you can see in the browser:   That's it! I hope someone find this post useful! Technorati Tags: ASP.NET,JavaScript,GridView

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  • Fixing a SkyDrive Sync Disaster

    - by Rick Strahl
    For a few months I've been using SkyDrive to handle some basic synching tasks for a number of folders of mine. Specifically I've been dumping a few of my development folders into sky drive so I have a live running backup. It had been working just fine until about a week ago when something went awry. Badly! The idea is that the SkyDrive should sync files, but somewhere in its sync relationship it appears that SkyDrive got confused and assumed it needed to sync back older files to my local machine from the SkyDrive server. So rather than syncing my newer files to the server SkyDrive was pushing older files back to me. Because SkyDrive is so slow actually updating data it's not unusual for SkyDrive to be far behind in syncing and apparently some files were out of date by several months. Of course this is insidious because I didn't notice it for quite some time. I'd been happily working away on my files when a few days ago I noted a bunch of files with -RasXps (my machine name) popping up in various folders. At first I thought my Git repository was giving me a fit, but eventually realized that SkyDrive was actually pushing old files into my monitored folders. To be fair SkyDrive did make backups of the existing files, but by the time I caught it there were literally a few thousand files scattered on my machine that were now updated with old files from online. Here's what some of this looks like: If you look at the directory list you see a bunch of files with a -RasXps postfix appended to them. Those are the files that SkyDrive replaced and backed up on my machine. As you can see the backed up files are actually newer than the ones it pulled from the online SkyDrive. Unless I modified the files after they were updated they all were older than the existing local files. Not exactly how I imagined my synching would work. At first I started cleaning up this mess manually. In most cases the obvious solution was to simply delete the original file and replace with the -RasXps file, but not in all files. Some scrutiny was required and besides being a pain in the ass to rename files, quite frequently I had to dig out Beyond Compare to compare a few files where it wasn't quite clear what's wrong. I quickly realized that doing this by hand would be too hard for the large number of files that got hosed. Hacking together a small .NET Utility So, I figured the easiest way to tackle this is to write a small utility app that shows me all the mangled files that have backups, allows me to compare them and then quickly select and update them, removing the -RasXps file after choosing one of the two files. What I ended up with was a quick and dirty WinForms app that allows me to pick a root folder, and then shows all the -MachineName files: I start by picking a base folder and a template to search for - typically the -MachineName. Clicking Go brings up a list of all files in that folder and its subdirectories.  The list also displays the dates for the saved (-MachineName) file and the current file on disk, along with highlighting for the newer of the two. I can right click on any file and get a context menu pop up to open the folder in Explorer, or open Beyond Compare and view the two files to compare differences which I found very helpful for a number of files where I had modified the files after SkyDrive had updated to an old one. Typically these would be the green files (of which there were thankfully few). To 'fix' files I can select any number of files in the list, then use one of the three buttons on the right to apply an operation. I can use the Saved files - that is the backup file that SkyDrive created with the -MachineName extension (-RasXps above). Or I can use the current file, which is the file with the right name on disk right now and delete the -MachineName file. Or on some occasions I can just opt to delete both of them. For some files like binaries it's often easier to just delete and them be rebuild than choosing. For the most part the process involves accepting the pink files, and checking the few green files and see if any modifications were made since the file was updated incorrectly by SkyDrive. For me luckily those are few in number. Anyways, I thought I share this utility in case anybody else runs into this issue. I've included the VS2012 solution and all the source code so you can see how it works and you can tweak it as needed. The .NET 4.5 binaries are also included if you can't compile. Be warned though!  This rough code is provided as is and makes no guarantees or claims about file safety. All three of the action buttons on the form will delete data. It's a very rough utility and there are no safeguards that ask nicely before deleting files. I highly recommend you make a backup before you have at it. This tools is very narrow in focus, but it might also work with other sync issues from other vendors. I seem to remember that I had similar issues with SugarSync at some point and it too created the -MachineName style files on sync conflicts. Hope this helps somebody out so you can avoid wasting the better part of a full work day on this… Resources Download the Source Code and Binaries for SkyDrive Rescue© Rick Strahl, West Wind Technologies, 2005-2013Posted in Windows  .NET   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • A simple Dynamic Proxy

    - by Abhijeet Patel
    Frameworks such as EF4 and MOQ do what most developers consider "dark magic". For instance in EF4, when you use a POCO for an entity you can opt-in to get behaviors such as "lazy-loading" and "change tracking" at runtime merely by ensuring that your type has the following characteristics: The class must be public and not sealed. The class must have a public or protected parameter-less constructor. The class must have public or protected properties Adhere to this and your type is magically endowed with these behaviors without any additional programming on your part. Behind the scenes the framework subclasses your type at runtime and creates a "dynamic proxy" which has these additional behaviors and when you navigate properties of your POCO, the framework replaces the POCO type with derived type instances. The MOQ framework does simlar magic. Let's say you have a simple interface:   public interface IFoo      {          int GetNum();      }   We can verify that the GetNum() was invoked on a mock like so:   var mock = new Mock<IFoo>(MockBehavior.Default);   mock.Setup(f => f.GetNum());   var num = mock.Object.GetNum();   mock.Verify(f => f.GetNum());   Beind the scenes the MOQ framework is generating a dynamic proxy by implementing IFoo at runtime. the call to moq.Object returns the dynamic proxy on which we then call "GetNum" and then verify that this method was invoked. No dark magic at all, just clever programming is what's going on here, just not visible and hence appears magical! Let's create a simple dynamic proxy generator which accepts an interface type and dynamically creates a proxy implementing the interface type specified at runtime.     public static class DynamicProxyGenerator   {       public static T GetInstanceFor<T>()       {           Type typeOfT = typeof(T);           var methodInfos = typeOfT.GetMethods();           AssemblyName assName = new AssemblyName("testAssembly");           var assBuilder = AppDomain.CurrentDomain.DefineDynamicAssembly(assName, AssemblyBuilderAccess.RunAndSave);           var moduleBuilder = assBuilder.DefineDynamicModule("testModule", "test.dll");           var typeBuilder = moduleBuilder.DefineType(typeOfT.Name + "Proxy", TypeAttributes.Public);              typeBuilder.AddInterfaceImplementation(typeOfT);           var ctorBuilder = typeBuilder.DefineConstructor(                     MethodAttributes.Public,                     CallingConventions.Standard,                     new Type[] { });           var ilGenerator = ctorBuilder.GetILGenerator();           ilGenerator.EmitWriteLine("Creating Proxy instance");           ilGenerator.Emit(OpCodes.Ret);           foreach (var methodInfo in methodInfos)           {               var methodBuilder = typeBuilder.DefineMethod(                   methodInfo.Name,                   MethodAttributes.Public | MethodAttributes.Virtual,                   methodInfo.ReturnType,                   methodInfo.GetParameters().Select(p => p.GetType()).ToArray()                   );               var methodILGen = methodBuilder.GetILGenerator();               methodILGen.EmitWriteLine("I'm a proxy");               if (methodInfo.ReturnType == typeof(void))               {                   methodILGen.Emit(OpCodes.Ret);               }               else               {                   if (methodInfo.ReturnType.IsValueType || methodInfo.ReturnType.IsEnum)                   {                       MethodInfo getMethod = typeof(Activator).GetMethod(/span>"CreateInstance",new Type[]{typeof((Type)});                                               LocalBuilder lb = methodILGen.DeclareLocal(methodInfo.ReturnType);                       methodILGen.Emit(OpCodes.Ldtoken, lb.LocalType);                       methodILGen.Emit(OpCodes.Call, typeofype).GetMethod("GetTypeFromHandle"));  ));                       methodILGen.Emit(OpCodes.Callvirt, getMethod);                       methodILGen.Emit(OpCodes.Unbox_Any, lb.LocalType);                                                              }                 else                   {                       methodILGen.Emit(OpCodes.Ldnull);                   }                   methodILGen.Emit(OpCodes.Ret);               }               typeBuilder.DefineMethodOverride(methodBuilder, methodInfo);           }                     Type constructedType = typeBuilder.CreateType();           var instance = Activator.CreateInstance(constructedType);           return (T)instance;       }   }   Dynamic proxies are created by calling into the following main types: AssemblyBuilder, TypeBuilder, Modulebuilder and ILGenerator. These types enable dynamically creating an assembly and emitting .NET modules and types in that assembly, all using IL instructions. Let's break down the code above a bit and examine it piece by piece                Type typeOfT = typeof(T);              var methodInfos = typeOfT.GetMethods();              AssemblyName assName = new AssemblyName("testAssembly");              var assBuilder = AppDomain.CurrentDomain.DefineDynamicAssembly(assName, AssemblyBuilderAccess.RunAndSave);              var moduleBuilder = assBuilder.DefineDynamicModule("testModule", "test.dll");              var typeBuilder = moduleBuilder.DefineType(typeOfT.Name + "Proxy", TypeAttributes.Public);   We are instructing the runtime to create an assembly caled "test.dll"and in this assembly we then emit a new module called "testModule". We then emit a new type definition of name "typeName"Proxy into this new module. This is the definition for the "dynamic proxy" for type T                 typeBuilder.AddInterfaceImplementation(typeOfT);               var ctorBuilder = typeBuilder.DefineConstructor(                         MethodAttributes.Public,                         CallingConventions.Standard,                         new Type[] { });               var ilGenerator = ctorBuilder.GetILGenerator();               ilGenerator.EmitWriteLine("Creating Proxy instance");               ilGenerator.Emit(OpCodes.Ret);   The newly created type implements type T and defines a default parameterless constructor in which we emit a call to Console.WriteLine. This call is not necessary but we do this so that we can see first hand that when the proxy is constructed, when our default constructor is invoked.   var methodBuilder = typeBuilder.DefineMethod(                      methodInfo.Name,                      MethodAttributes.Public | MethodAttributes.Virtual,                      methodInfo.ReturnType,                      methodInfo.GetParameters().Select(p => p.GetType()).ToArray()                      );   We then iterate over each method declared on type T and add a method definition of the same name into our "dynamic proxy" definition     if (methodInfo.ReturnType == typeof(void))   {       methodILGen.Emit(OpCodes.Ret);   }   If the return type specified in the method declaration of T is void we simply return.     if (methodInfo.ReturnType.IsValueType || methodInfo.ReturnType.IsEnum)   {                               MethodInfo getMethod = typeof(Activator).GetMethod("CreateInstance",                                                         new Type[]{typeof(Type)});                               LocalBuilder lb = methodILGen.DeclareLocal(methodInfo.ReturnType);                                                     methodILGen.Emit(OpCodes.Ldtoken, lb.LocalType);       methodILGen.Emit(OpCodes.Call, typeof(Type).GetMethod("GetTypeFromHandle"));       methodILGen.Emit(OpCodes.Callvirt, getMethod);       methodILGen.Emit(OpCodes.Unbox_Any, lb.LocalType);   }   If the return type in the method declaration of T is either a value type or an enum, then we need to create an instance of the value type and return that instance the caller. In order to accomplish that we need to do the following: 1) Get a handle to the Activator.CreateInstance method 2) Declare a local variable which represents the Type of the return type(i.e the type object of the return type) specified on the method declaration of T(obtained from the MethodInfo) and push this Type object onto the evaluation stack. In reality a RuntimeTypeHandle is what is pushed onto the stack. 3) Invoke the "GetTypeFromHandle" method(a static method in the Type class) passing in the RuntimeTypeHandle pushed onto the stack previously as an argument, the result of this invocation is a Type object (representing the method's return type) which is pushed onto the top of the evaluation stack. 4) Invoke Activator.CreateInstance passing in the Type object from step 3, the result of this invocation is an instance of the value type boxed as a reference type and pushed onto the top of the evaluation stack. 5) Unbox the result and place it into the local variable of the return type defined in step 2   methodILGen.Emit(OpCodes.Ldnull);   If the return type is a reference type then we just load a null onto the evaluation stack   methodILGen.Emit(OpCodes.Ret);   Emit a a return statement to return whatever is on top of the evaluation stack(null or an instance of a value type) back to the caller     Type constructedType = typeBuilder.CreateType();   var instance = Activator.CreateInstance(constructedType);   return (T)instance;   Now that we have a definition of the "dynamic proxy" implementing all the methods declared on T, we can now create an instance of the proxy type and return that out typed as T. The caller can now invoke the generator and request a dynamic proxy for any type T. In our example when the client invokes GetNum() we get back "0". Lets add a new method on the interface called DayOfWeek GetDay()   public interface IFoo      {          int GetNum();          DayOfWeek GetDay();      }   When GetDay() is invoked, the "dynamic proxy" returns "Sunday" since that is the default value for the DayOfWeek enum This is a very trivial example of dynammic proxies, frameworks like MOQ have a way more sophisticated implementation of this paradigm where in you can instruct the framework to create proxies which return specified values for a method implementation.

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  • Silverlight Recruiting Application Part 4 - Navigation and Modules

    After our brief intermission (and the craziness of Q1 2010 release week), we're back on track here and today we get to dive into how we are going to navigate through our applications as well as how to set up our modules. That way, as I start adding the functionality- adding Jobs and Applicants, Interview Scheduling, and finally a handy Dashboard- you'll see how everything is communicating back and forth. This is all leading up to an eventual webinar, in which I'll dive into this process and give a honest look at the current story for MVVM vs. Code-Behind applications. (For a look at the future with SL4 and a little thing called MEF, check out what Ross is doing over at his blog!) Preamble... Before getting into really talking about this app, I've done a little bit of work ahead of time to create a ton of files that I'll need. Since the webinar is going to cover the Dashboard, it's not here, but otherwise this is a look at what the project layout looks like (and remember, this is both projects since they share the .Web): So as you can see, from an architecture perspective, the code-behind app is much smaller and more streamlined- aka a better fit for the one man shop that is me. Each module in the MVVM app has the same setup, which is the Module class and corresponding Views and ViewModels. Since the code-behind app doesn't need a go-between project like Infrastructure, each MVVM module is instead replaced by a single Silverlight UserControl which will contain all the logic for each respective bit of functionality. My Very First Module Navigation is going to be key to my application, so I figured the first thing I would setup is my MenuModule. First step here is creating a Silverlight Class Library named MenuModule, creatingthe View and ViewModel folders, and adding the MenuModule.cs class to handle module loading. The most important thing here is that my MenuModule inherits from IModule, which runs an Initialize on each module as it is created that, in my case, adds the views to the correct regions. Here's the MenuModule.cs code: public class MenuModule : IModule { private readonly IRegionManager regionManager; private readonly IUnityContainer container; public MenuModule(IUnityContainer container, IRegionManager regionmanager) { this.container = container; this.regionManager = regionmanager; } public void Initialize() { var addMenuView = container.Resolve<MenuView>(); regionManager.Regions["MenuRegion"].Add(addMenuView); } } Pretty straightforward here... We inject a container and region manager from Prism/Unity, then upon initialization we grab the view (out of our Views folder) and add it to the region it needs to live in. Simple, right? When the MenuView is created, the only thing in the code-behind is a reference to the set the MenuViewModel as the DataContext. I'd like to achieve MVVM nirvana and have zero code-behind by placing the viewmodel in the XAML, but for the reasons listed further below I can't. Navigation - MVVM Since navigation isn't the biggest concern in putting this whole thing together, I'm using the Button control to handle different options for loading up views/modules. There is another reason for this- out of the box, Prism has command support for buttons, which is one less custom command I had to work up for the functionality I would need. This comes from the Microsoft.Practices.Composite.Presentation assembly and looks as follows when put in code: <Button x:Name="xGoToJobs" Style="{StaticResource menuStyle}" Content="Jobs" cal:Click.Command="{Binding GoModule}" cal:Click.CommandParameter="JobPostingsView" /> For quick reference, 'menuStyle' is just taking care of margins and spacing, otherwise it looks, feels, and functions like everyone's favorite Button. What MVVM's this up is that the Click.Command is tying to a DelegateCommand (also coming fromPrism) on the backend. This setup allows you to tie user interaction to a command you setup in your viewmodel, which replaces the standard event-based setup you'd see in the code-behind app. Due to databinding magic, it all just works. When we get looking at the DelegateCommand in code, it ends up like this: public class MenuViewModel : ViewModelBase { private readonly IRegionManager regionManager; public DelegateCommand<object> GoModule { get; set; } public MenuViewModel(IRegionManager regionmanager) { this.regionManager = regionmanager; this.GoModule = new DelegateCommand<object>(this.goToView); } public void goToView(object obj) { MakeMeActive(this.regionManager, "MainRegion", obj.ToString()); } } Another for reference, ViewModelBase takes care of iNotifyPropertyChanged and MakeMeActive, which switches views in the MainRegion based on the parameters. So our public DelegateCommand GoModule ties to our command on the view, that in turn calls goToView, and the parameter on the button is the name of the view (which we pass with obj.ToString()) to activate. And how do the views get the names I can pass as a string? When I called regionManager.Regions[regionname].Add(view), there is an overload that allows for .Add(view, "viewname"), with viewname being what I use to activate views. You'll see that in action next installment, just wanted to clarify how that works. With this setup, I create two more buttons in my MenuView and the MenuModule is good to go. Last step is to make sure my MenuModule loads in my Bootstrapper: protected override IModuleCatalog GetModuleCatalog() { ModuleCatalog catalog = new ModuleCatalog(); // add modules here catalog.AddModule(typeof(MenuModule.MenuModule)); return catalog; } Clean, simple, MVVM-delicious. Navigation - Code-Behind Keeping with the history of significantly shorter code-behind sections of this series, Navigation will be no different. I promise. As I explained in a prior post, due to the one-project setup I don't have to worry about the same concerns so my menu is part of MainPage.xaml. So I can cheese-it a bit, though, since I've already got three buttons all set I'm just copying that code and adding three click-events instead of the command/commandparameter setup: <!-- Menu Region --> <StackPanel Grid.Row="1" Orientation="Vertical"> <Button x:Name="xJobsButton" Content="Jobs" Style="{StaticResource menuStyleCB}" Click="xJobsButton_Click" /> <Button x:Name="xApplicantsButton" Content="Applicants" Style="{StaticResource menuStyleCB}" Click="xApplicantsButton_Click" /> <Button x:Name="xSchedulingModule" Content="Scheduling" Style="{StaticResource menuStyleCB}" Click="xSchedulingModule_Click" /> </StackPanel> Simple, easy to use events, and no extra assemblies required! Since the code for loading each view will be similar, we'll focus on JobsView for now.The code-behind with this setup looks something like... private JobsView _jobsView; public MainPage() { InitializeComponent(); } private void xJobsButton_Click(object sender, RoutedEventArgs e) { if (MainRegion.Content.GetType() != typeof(JobsView)) { if (_jobsView == null) _jobsView = new JobsView(); MainRegion.Content = _jobsView; } } What am I doing here? First, for each 'view' I create a private reference which MainPage will hold on to. This allows for a little bit of state-maintenance when switching views. When a button is clicked, first we make sure the 'view' typeisn't active (why load it again if it is already at center stage?), then we check if the view has been created and create if necessary, then load it up. Three steps to switching views and is easy as pie. Part 4 Results The end result of all this is that I now have a menu module (MVVM) and a menu section (code-behind) that load their respective views. Since I'm using the same exact XAML (except with commands/events depending on the project), the end result for both is again exactly the same and I'll show a slightly larger image to show it off: Next time, we add the Jobs Module and wire up RadGridView and a separate edit page to handle adding and editing new jobs. That's when things get fun. And somewhere down the line, I'll make the menu look slicker. :) Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • OpenCV install problems on Studio 12.04 - broken dependencies

    - by Will
    I'm trying to follow the Ubuntu OpenCV documentation at OpenCV. The provided script has a line which executed for some time, taking away more packages than I expected (such as ubuntu-studio video); sudo apt-get -qq remove ffmpeg x264 libx264-dev When the script gets to the line below, it bombs; sudo apt-get -qq install libopencv-dev build-essential checkinstall cmake pkg-config yasm libtiff4-dev libjpeg-dev libjasper-dev libavcodec-dev libavformat-dev libswscale-dev libdc1394-22-dev libxine-dev libgstreamer0.10-dev libgstreamer-plugins-base0.10-dev libv4l-dev python-dev python-numpy libtbb-dev libqt4-dev libgtk2.0-dev libfaac-dev libmp3lame-dev libopencore-amrnb-dev libopencore-amrwb-dev libtheora-dev libvorbis-dev libxvidcore-dev x264 v4l-utils ffmpeg The error msg is; E: Unable to correct problems, you have held broken packages. I've since run Update-Manager, run sudo apt-get updates, rebooted, tried the above script line manually, and still no change. I've just run sudo apt-get install -f and nothing seemed to change. It did mention that some packages were no longer needed and could be removed by apt-get autoremove, so I ran that. It removed a number of packages, so I reran the install command above. Still same problem of held broken packages. I just ran sudo apt-get -u dist-upgrade Part of the response was; The following packages have been kept back: gstreamer0.10-ffmpeg I'm not sure what that means. I do know that it shows up in my Update-Manager and cannot be checked I then ran sudo dpkg --configure -a and then reran sudo apt-get -f install and the package was still not upgraded, though there was this very interesting comment; Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: gstreamer0.10-ffmpeg : Depends: libavcodec53 (< 5:0) but it is not going to be installed or libavcodec-extra-53 (< 5:0) but 5:0.7.2-1ubuntu1+codecs1~oneiric2 is to be installed E: Unable to correct problems, you have held broken packages. Then I ran sudo apt-get -u dist-upgrade It showed I had one held package, so I ran; sudo apt-get -o Debug::pkgProblemResolver=yes dist-upgrade It also exited without upgrading the package, so I ran; sudo apt-get remove --dry-run gstreamer0.10-ffmpeg:i386 And it gave me; *The following packages will be REMOVED: arista gstreamer0.10-ffmpeg 0 upgraded, 0 newly installed, 2 to remove and 0 not upgraded. Remv arista [0.9.7-3ubuntu1] Remv gstreamer0.10-ffmpeg [0.10.12-1ubuntu1]* But when I reran sudo apt-get -u dist-upgrade It showed the package was still there. *The following packages have been kept back: gstreamer0.10-ffmpeg 0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.* Update: Just went into Synaptic PM and completely removed gstreamer0.10-ffmpeg Reran sudo apt-get -u dist-upgrade And was told; 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. However, when I ran the original apt-get to install opencv (first code at the top of this question), it still gave me the same broken package errors. So I tried $ cat /etc/apt/sources.list # # deb cdrom:[Ubuntu-Studio 11.10 _Oneiric Ocelot_ - Release i386 (20111011.1)]/ oneiric main multiverse restricted universe # deb cdrom:[Ubuntu-Studio 11.10 _Oneiric Ocelot_ - Release i386 (20111011.1)]/ oneiric main multiverse restricted universe # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. deb http://us.archive.ubuntu.com/ubuntu/ precise main restricted deb-src http://us.archive.ubuntu.com/ubuntu/ precise main restricted ## Major bug fix updates produced after the final release of the ## distribution. deb http://us.archive.ubuntu.com/ubuntu/ precise-updates main restricted deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates main restricted ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. deb http://us.archive.ubuntu.com/ubuntu/ precise universe deb-src http://us.archive.ubuntu.com/ubuntu/ precise universe deb http://us.archive.ubuntu.com/ubuntu/ precise-updates universe deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates universe ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team, and may not be under a free licence. Please satisfy yourself as to ## your rights to use the software. Also, please note that software in ## multiverse WILL NOT receive any review or updates from the Ubuntu ## security team. deb http://us.archive.ubuntu.com/ubuntu/ precise multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ precise multiverse deb http://us.archive.ubuntu.com/ubuntu/ precise-updates multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates multiverse ## N.B. software from this repository may not have been tested as ## extensively as that contained in the main release, although it includes ## newer versions of some applications which may provide useful features. ## Also, please note that software in backports WILL NOT receive any review ## or updates from the Ubuntu security team. deb http://security.ubuntu.com/ubuntu precise-security main restricted deb-src http://security.ubuntu.com/ubuntu precise-security main restricted deb http://security.ubuntu.com/ubuntu precise-security universe deb-src http://security.ubuntu.com/ubuntu precise-security universe deb http://security.ubuntu.com/ubuntu precise-security multiverse deb-src http://security.ubuntu.com/ubuntu precise-security multiverse ## Uncomment the following two lines to add software from Canonical's ## 'partner' repository. ## This software is not part of Ubuntu, but is offered by Canonical and the ## respective vendors as a service to Ubuntu users. deb http://archive.canonical.com/ubuntu precise partner # deb-src http://archive.canonical.com/ubuntu oneiric partner ## Uncomment the following two lines to add software from Ubuntu's ## 'extras' repository. ## This software is not part of Ubuntu, but is offered by third-party ## developers who want to ship their latest software. # deb http://extras.ubuntu.com/ubuntu oneiric main # deb-src http://extras.ubuntu.com/ubuntu oneiric main # deb http://download.opensuse.org/repositories/home:/popinet/xUbuntu_11.04 ./ # disabled on upgrade to precise and then; $ cat /etc/apt/sources.list.d/* But I don't have enough reputation to post the results here (it says I need at least 10 reputation points to post more than 2 links), so I don't know how to provide the requested feedback. Then tried; $ sudo apt-get check [sudo] password for <abcd>: Reading package lists... Done Building dependency tree Reading state information... Done However, no resolution of the problem yet. What else do I need to do? Will an upgrade to Ubuntu Studio 13.xx solve this problem (or compound it)?

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  • Replication Services as ETL extraction tool

    - by jorg
    In my last blog post I explained the principles of Replication Services and the possibilities it offers in a BI environment. One of the possibilities I described was the use of snapshot replication as an ETL extraction tool: “Snapshot Replication can also be useful in BI environments, if you don’t need a near real-time copy of the database, you can choose to use this form of replication. Next to an alternative for Transactional Replication it can be used to stage data so it can be transformed and moved into the data warehousing environment afterwards. In many solutions I have seen developers create multiple SSIS packages that simply copies data from one or more source systems to a staging database that figures as source for the ETL process. The creation of these packages takes a lot of (boring) time, while Replication Services can do the same in minutes. It is possible to filter out columns and/or records and it can even apply schema changes automatically so I think it offers enough features here. I don’t know how the performance will be and if it really works as good for this purpose as I expect, but I want to try this out soon!” Well I have tried it out and I must say it worked well. I was able to let replication services do work in a fraction of the time it would cost me to do the same in SSIS. What I did was the following: Configure snapshot replication for some Adventure Works tables, this was quite simple and straightforward. Create an SSIS package that executes the snapshot replication on demand and waits for its completion. This is something that you can’t do with out of the box functionality. While configuring the snapshot replication two SQL Agent Jobs are created, one for the creation of the snapshot and one for the distribution of the snapshot. Unfortunately these jobs are  asynchronous which means that if you execute them they immediately report back if the job started successfully or not, they do not wait for completion and report its result afterwards. So I had to create an SSIS package that executes the jobs and waits for their completion before the rest of the ETL process continues. Fortunately I was able to create the SSIS package with the desired functionality. I have made a step-by-step guide that will help you configure the snapshot replication and I have uploaded the SSIS package you need to execute it. Configure snapshot replication   The first step is to create a publication on the database you want to replicate. Connect to SQL Server Management Studio and right-click Replication, choose for New.. Publication…   The New Publication Wizard appears, click Next Choose your “source” database and click Next Choose Snapshot publication and click Next   You can now select tables and other objects that you want to publish Expand Tables and select the tables that are needed in your ETL process In the next screen you can add filters on the selected tables which can be very useful. Think about selecting only the last x days of data for example. Its possible to filter out rows and/or columns. In this example I did not apply any filters. Schedule the Snapshot Agent to run at a desired time, by doing this a SQL Agent Job is created which we need to execute from a SSIS package later on. Next you need to set the Security Settings for the Snapshot Agent. Click on the Security Settings button.   In this example I ran the Agent under the SQL Server Agent service account. This is not recommended as a security best practice. Fortunately there is an excellent article on TechNet which tells you exactly how to set up the security for replication services. Read it here and make sure you follow the guidelines!   On the next screen choose to create the publication at the end of the wizard Give the publication a name (SnapshotTest) and complete the wizard   The publication is created and the articles (tables in this case) are added Now the publication is created successfully its time to create a new subscription for this publication.   Expand the Replication folder in SSMS and right click Local Subscriptions, choose New Subscriptions   The New Subscription Wizard appears   Select the publisher on which you just created your publication and select the database and publication (SnapshotTest)   You can now choose where the Distribution Agent should run. If it runs at the distributor (push subscriptions) it causes extra processing overhead. If you use a separate server for your ETL process and databases choose to run each agent at its subscriber (pull subscriptions) to reduce the processing overhead at the distributor. Of course we need a database for the subscription and fortunately the Wizard can create it for you. Choose for New database   Give the database the desired name, set the desired options and click OK You can now add multiple SQL Server Subscribers which is not necessary in this case but can be very useful.   You now need to set the security settings for the Distribution Agent. Click on the …. button Again, in this example I ran the Agent under the SQL Server Agent service account. Read the security best practices here   Click Next   Make sure you create a synchronization job schedule again. This job is also necessary in the SSIS package later on. Initialize the subscription at first synchronization Select the first box to create the subscription when finishing this wizard Complete the wizard by clicking Finish The subscription will be created In SSMS you see a new database is created, the subscriber. There are no tables or other objects in the database available yet because the replication jobs did not ran yet. Now expand the SQL Server Agent, go to Jobs and search for the job that creates the snapshot:   Rename this job to “CreateSnapshot” Now search for the job that distributes the snapshot:   Rename this job to “DistributeSnapshot” Create an SSIS package that executes the snapshot replication We now need an SSIS package that will take care of the execution of both jobs. The CreateSnapshot job needs to execute and finish before the DistributeSnapshot job runs. After the DistributeSnapshot job has started the package needs to wait until its finished before the package execution finishes. The Execute SQL Server Agent Job Task is designed to execute SQL Agent Jobs from SSIS. Unfortunately this SSIS task only executes the job and reports back if the job started succesfully or not, it does not report if the job actually completed with success or failure. This is because these jobs are asynchronous. The SSIS package I’ve created does the following: It runs the CreateSnapshot job It checks every 5 seconds if the job is completed with a for loop When the CreateSnapshot job is completed it starts the DistributeSnapshot job And again it waits until the snapshot is delivered before the package will finish successfully Quite simple and the package is ready to use as standalone extract mechanism. After executing the package the replicated tables are added to the subscriber database and are filled with data:   Download the SSIS package here (SSIS 2008) Conclusion In this example I only replicated 5 tables, I could create a SSIS package that does the same in approximately the same amount of time. But if I replicated all the 70+ AdventureWorks tables I would save a lot of time and boring work! With replication services you also benefit from the feature that schema changes are applied automatically which means your entire extract phase wont break. Because a snapshot is created using the bcp utility (bulk copy) it’s also quite fast, so the performance will be quite good. Disadvantages of using snapshot replication as extraction tool is the limitation on source systems. You can only choose SQL Server or Oracle databases to act as a publisher. So if you plan to build an extract phase for your ETL process that will invoke a lot of tables think about replication services, it would save you a lot of time and thanks to the Extract SSIS package I’ve created you can perfectly fit it in your usual SSIS ETL process.

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  • Who is Jeremiah Owyang?

    - by Michael Hylton
    12.00 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Q: What’s your current role and what career path brought you here? J.O.: I'm currently a partner and one of the founding team members at Altimeter Group.  I'm currently the Research Director, as well as wear the hat of Industry Analyst. Prior to joining Altimeter, I was an Industry Analyst at Forrester covering Social Computing, and before that, deployed and managed the social media program at Hitachi Data Systems in Santa Clara.  Around that time, I started a career blog called Web Strategy which focused on how companies were using the web to connect with customers --and never looked back. Q: As an industry analyst, what are you focused on these days? J.O.: There are three trends that I'm focused my research on at this time:  1) The Dynamic Customer Journey:  Individuals (both b2c and b2b) are given so many options in their sources of data, channels to choose from and screens to consume them on that we've found that at each given touchpoint there are 75 potential permutations.  Companies that can map this, then deliver information to individuals when they need it will have a competitive advantage and we want to find out who's doing this.  2) One of the sub themes that supports this trend is Social Performance.  Yesterday's social web was disparate engagement of humans, but the next phase will be data driven, and soon new technologies will emerge to help all those that are consuming, publishing, and engaging on the social web to be more efficient with their time through forms of automation.  As you might expect, this comes with upsides and downsides.  3) The Sentient World is our research theme that looks out the furthest as the world around us (even inanimate objects) become 'self aware' and are able to talk back to us via digital devices and beyond.  Big data, internet of things, mobile devices will all be this next set. Q: People cite that the line between work and life is getting more and more blurred. Do you see your personal life influencing your professional work? J.O.: The lines between our work and personal lives are dissolving, and this leads to a greater upside of being always connected and have deeper relationships with those that are not.  It also means a downside of society expectations that we're always around and available for colleagues, customers, and beyond.  In the future, a balance will be sought as we seek to achieve the goals of family, friends, work, and our own personal desires.  All of this is being ironically written at 430 am on a Sunday am.  Q: How can people keep up with what you’re working on? J.O.: A great question, thanks.  There are a few sources of information to find out, I'll lead with the first which is my blog at web-strategist.com.  A few times a week I'll publish my industry insights (hires, trends, forces, funding, M&A, business needs) as well as on twitter where I'll point to all the news that's fit to print @jowyang.  As my research reports go live (we publish them for all to read --called Open Research-- at no cost) they'll emerge on my blog, or checkout the research tab to find out more now.  http://www.web-strategist.com/blog/research/ Q: Recently, you’ve been working with us here at Oracle on something exciting coming up later this week. What’s on the horizon?  J.O.: Absolutely! This coming Thursday, September 13th, I’m doing a webcast with Oracle on “Managing Social Relationships for the Enterprise”. This is going to be a great discussion with Reggie Bradford, Senior Vice President of Product Development at Oracle and Christian Finn, Senior Director of Product Management for Oracle WebCenter. I’m looking forward to a great discussion around all those issues that so many companies are struggling with these days as they realize how much social media is impacting their business. It’s changing the way your customers and employees interact with your brand. Today it’s no longer a matter of when to become a social-enabled enterprise, but how to become a successful one. 12.00 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Q: You’ve been very actively pursued for media interviews and conference and company speaking engagements – anything you’d like to share to give us a sneak peak of what to expect on Thursday’s webcast?  J.O.: Below is a 15 minute video which encapsulates Altimeter’s themes on the Dynamic Customer Journey and the Sentient World. I’m really proud to have taken an active role in the first ever LeWeb outside of Paris. This one, which was featured in downtown London across the street from Westminster Abbey was sold out. If you’ve not heard of LeWeb, this is a global Internet conference hosted by Loic and Geraldine Le Meur, a power couple that stem from Paris but are also living in Silicon Valley, this is one of my favorite conferences to connect with brands, technology innovators, investors and friends. Altimeter was able to play a minor role in suggesting the theme for the event “Faster Than Real Time” which stems off previous LeWebs that focused on the “Real time web”. In this radical state, companies are able to anticipate the needs of their customers by using data, technology, and devices and deliver meaningful experiences before customers even know they need it. I explore two of three of Altimeter’s research themes, the Dynamic Customer Journey, and the Sentient World in my speech, but due to time, did not focus on Adaptive Organization.

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  • Who is Jeremiah Owyang?

    - by Michael Snow
    12.00 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Q: What’s your current role and what career path brought you here? J.O.: I'm currently a partner and one of the founding team members at Altimeter Group.  I'm currently the Research Director, as well as wear the hat of Industry Analyst. Prior to joining Altimeter, I was an Industry Analyst at Forrester covering Social Computing, and before that, deployed and managed the social media program at Hitachi Data Systems in Santa Clara.  Around that time, I started a career blog called Web Strategy which focused on how companies were using the web to connect with customers --and never looked back. Q: As an industry analyst, what are you focused on these days? J.O.: There are three trends that I'm focused my research on at this time:  1) The Dynamic Customer Journey:  Individuals (both b2c and b2b) are given so many options in their sources of data, channels to choose from and screens to consume them on that we've found that at each given touchpoint there are 75 potential permutations.  Companies that can map this, then deliver information to individuals when they need it will have a competitive advantage and we want to find out who's doing this.  2) One of the sub themes that supports this trend is Social Performance.  Yesterday's social web was disparate engagement of humans, but the next phase will be data driven, and soon new technologies will emerge to help all those that are consuming, publishing, and engaging on the social web to be more efficient with their time through forms of automation.  As you might expect, this comes with upsides and downsides.  3) The Sentient World is our research theme that looks out the furthest as the world around us (even inanimate objects) become 'self aware' and are able to talk back to us via digital devices and beyond.  Big data, internet of things, mobile devices will all be this next set. Q: People cite that the line between work and life is getting more and more blurred. Do you see your personal life influencing your professional work? J.O.: The lines between our work and personal lives are dissolving, and this leads to a greater upside of being always connected and have deeper relationships with those that are not.  It also means a downside of society expectations that we're always around and available for colleagues, customers, and beyond.  In the future, a balance will be sought as we seek to achieve the goals of family, friends, work, and our own personal desires.  All of this is being ironically written at 430 am on a Sunday am.  Q: How can people keep up with what you’re working on? J.O.: A great question, thanks.  There are a few sources of information to find out, I'll lead with the first which is my blog at web-strategist.com.  A few times a week I'll publish my industry insights (hires, trends, forces, funding, M&A, business needs) as well as on twitter where I'll point to all the news that's fit to print @jowyang.  As my research reports go live (we publish them for all to read --called Open Research-- at no cost) they'll emerge on my blog, or checkout the research tab to find out more now.  http://www.web-strategist.com/blog/research/ Q: Recently, you’ve been working with us here at Oracle on something exciting coming up later this week. What’s on the horizon?  J.O.: Absolutely! This coming Thursday, September 13th, I’m doing a webcast with Oracle on “Managing Social Relationships for the Enterprise”. This is going to be a great discussion with Reggie Bradford, Senior Vice President of Product Development at Oracle and Christian Finn, Senior Director of Product Management for Oracle WebCenter. I’m looking forward to a great discussion around all those issues that so many companies are struggling with these days as they realize how much social media is impacting their business. It’s changing the way your customers and employees interact with your brand. Today it’s no longer a matter of when to become a social-enabled enterprise, but how to become a successful one. 12.00 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Q: You’ve been very actively pursued for media interviews and conference and company speaking engagements – anything you’d like to share to give us a sneak peak of what to expect on Thursday’s webcast?  J.O.: Below is a 15 minute video which encapsulates Altimeter’s themes on the Dynamic Customer Journey and the Sentient World. I’m really proud to have taken an active role in the first ever LeWeb outside of Paris. This one, which was featured in downtown London across the street from Westminster Abbey was sold out. If you’ve not heard of LeWeb, this is a global Internet conference hosted by Loic and Geraldine Le Meur, a power couple that stem from Paris but are also living in Silicon Valley, this is one of my favorite conferences to connect with brands, technology innovators, investors and friends. Altimeter was able to play a minor role in suggesting the theme for the event “Faster Than Real Time” which stems off previous LeWebs that focused on the “Real time web”. In this radical state, companies are able to anticipate the needs of their customers by using data, technology, and devices and deliver meaningful experiences before customers even know they need it. I explore two of three of Altimeter’s research themes, the Dynamic Customer Journey, and the Sentient World in my speech, but due to time, did not focus on Adaptive Organization.

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  • Help me solve my problem with NPR Media Player

    - by Calcipher
    First of, let me apologize for this getting a bit technical. Several weeks ago, I found that while using NPR's media player (e.g. click on 'Listen to the Show' - this is what I've been using as a test) the stream would suddenly halt after a minute or three. I could not get the stream to restart without reloading the page. Now, I assumed this was an issue with NPR's player and Linux (or just a bug in their stuff in general) so I began to dig, the following is what I have tried to date (please note, the tldr; option is to skip to the latest thing as I think I know what is causing the problem). Note: All testing has been done, for consistency purposes, on a clean install of Chromium with no pluggins running. My machine is Ubuntu 10.10x64. First thing I always try, I disabled all firewall stuff on the system (UFW, default deny all, allow ssh). No change, firewall back up for all additional tests unless otherwise noted. In any case, UFW is stateful, so connections it started on a non-specified on different ports will continue to work. I deleted my ~/.macromeda and ~/.adobe folders, restarted (just to be sure) and tried. Program still froze. I decided the problem might be with my install of flash, so I purged the version I had (and the home folders again). I installed the x64 version of flash from a PPA. This had no effect. I decided that the problem might be with the version of flash, so I purged the x64 version and installed the standard x32 version that comes with Ubuntu. No luck. Back to the x64 version for consistency, I decided to set up a 64-bit mini 'clone' of my system in VirtualBox. I was able to run the media player with no problem. I rsynced (in archive mode) my home directory from my real machine to the virtual machine (with bridged networking, so it was fully visible on the network). I also used a few tricks to install ALL of the same software (and repositories) from the real machine to the virtual machine. I was still able to listen to the player. I decided that the problem was with my install (after all, it had gone through two major version upgrades). As I have /home/ on a separate partition it was easy to reinstall and use the same trick from #6 to have my system up and running again within about an hour. I continue to have issues with the NPR Media Player. By this point the weekend had come. At work, I use a wired connection while at home I use a wireless connection. For some reason I forgot that I was having problems and used the NPR Media Player over the weekend. Low and behold it worked just fine at home on wireless (note: for various reasons, I could not test this on wired at home). Following from #6, I decided that the problem was either something with the network at work or still something with my account. As the latter was easier to test, I created a new account on my system and used that at work. The Media Player worked. At a loss, I decided to watch the traffic with tshark (the text based brother of wireshark) - X's to protect the innocent, I am the XXX.24.200.XXX: sudo tshark -i eth0 -p -t a -R "ip.addr == XXX.24.200.XXX && ip.addr == XXX.166.98.XXX" As you would expect, there were tons and tons of packets, but each and every time the player froze, this is what I got 08:42:20.679200 XXX.166.98.XXX - XXX.24.200.XXX TCP macromedia-fcs 56371 [PSH, ACK] Seq=817686 Ack=6 Win=65535 Len=1448 TSV=495713325 TSER=396467 08:42:20.718602 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=396475 TSER=495713325 08:42:21.050183 XXX.166.98.XXX - XXX.24.200.XXX TCP [TCP ZeroWindowProbe] macromedia-fcs 56371 [ACK] Seq=819134 Ack=6 Win=65535 Len=1 TSV=495713362 TSER=396475 08:42:21.050221 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindowProbeAck] [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=396508 TSER=495713362 08:42:21.680548 XXX.166.98.XXX - XXX.24.200.XXX TCP [TCP ZeroWindowProbe] macromedia-fcs 56371 [ACK] Seq=819134 Ack=6 Win=65535 Len=1 TSV=495713425 TSER=396508 08:42:21.680605 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindowProbeAck] [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=396571 TSER=495713425 08:42:22.910354 XXX.166.98.XXX - XXX.24.200.XXX TCP [TCP ZeroWindowProbe] macromedia-fcs 56371 [ACK] Seq=819134 Ack=6 Win=65535 Len=1 TSV=495713548 TSER=396571 08:42:22.910400 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindowProbeAck] [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=396694 TSER=495713548 08:42:25.340458 XXX.166.98.XXX - XXX.24.200.XXX TCP [TCP ZeroWindowProbe] macromedia-fcs 56371 [ACK] Seq=819134 Ack=6 Win=65535 Len=1 TSV=495713791 TSER=396694 08:42:25.340517 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindowProbeAck] [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=396937 TSER=495713791 08:42:30.170698 XXX.166.98.XXX - XXX.24.200.XXX TCP [TCP ZeroWindowProbe] macromedia-fcs 56371 [ACK] Seq=819134 Ack=6 Win=65535 Len=1 TSV=495714274 TSER=396937 08:42:30.170746 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindowProbeAck] [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=397420 TSER=495714274 08:42:39.801738 XXX.166.98.XXX - XXX.24.200.XXX TCP [TCP ZeroWindowProbe] macromedia-fcs 56371 [ACK] Seq=819134 Ack=6 Win=65535 Len=1 TSV=495715237 TSER=397420 08:42:39.801784 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindowProbeAck] [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=398383 TSER=495715237 08:42:59.032648 XXX.166.98.XXX - XXX.24.200.XXX TCP [TCP ZeroWindowProbe] macromedia-fcs 56371 [ACK] Seq=819134 Ack=6 Win=65535 Len=1 TSV=495717160 TSER=398383 08:42:59.032696 XXX.24.200.XXX - XXX.166.98.XXX TCP [TCP ZeroWindowProbeAck] [TCP ZeroWindow] 56371 macromedia-fcs [ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=400306 TSER=495717160 08:43:00.267721 XXX.24.200.XXX - XXX.166.98.XXX TCP 56371 macromedia-fcs [FIN, ACK] Seq=6 Ack=819134 Win=0 Len=0 TSV=400430 TSER=495717160 08:43:00.267827 XXX.24.200.XXX - XXX.166.98.XXX TCP 56371 macromedia-fcs [RST, ACK] Seq=7 Ack=819134 Win=65535 Len=0 TSV=400430 TSER=495717160 So, as you can see, my machine is sending out a ZeroWindow packet (which I think means some buffer or another filled up) which causes the Media Player to halt (unfortunately, terminally - no controls on it really do anything anymore). Any ideas, at all, what would cause this? Why only on eth0 under my main account?

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  • How to configure VPN in Windows XP

    - by SAMIR BHOGAYTA
    VPN Overview A VPN is a private network created over a public one. It’s done with encryption, this way, your data is encapsulated and secure in transit – this creates the ‘virtual’ tunnel. A VPN is a method of connecting to a private network by a public network like the Internet. An internet connection in a company is common. An Internet connection in a Home is common too. With both of these, you could create an encrypted tunnel between them and pass traffic, safely - securely. If you want to create a VPN connection you will have to use encryption to make sure that others cannot intercept the data in transit while traversing the Internet. Windows XP provides a certain level of security by using Point-to-Point Tunneling Protocol (PPTP) or Layer Two Tunneling Protocol (L2TP). They are both considered tunneling protocols – simply because they create that virtual tunnel just discussed, by applying encryption. Configure a VPN with XP If you want to configure a VPN connection from a Windows XP client computer you only need what comes with the Operating System itself, it's all built right in. To set up a connection to a VPN, do the following: 1. On the computer that is running Windows XP, confirm that the connection to the Internet is correctly configured. • You can try to browse the internet • Ping a known host on the Internet, like yahoo.com, something that isn’t blocking ICMP 2. Click Start, and then click Control Panel. 3. In Control Panel, double click Network Connections 4. Click Create a new connection in the Network Tasks task pad 5. In the Network Connection Wizard, click Next. 6. Click Connect to the network at my workplace, and then click Next. 7. Click Virtual Private Network connection, and then click Next. 8. If you are prompted, you need to select whether you will use a dialup connection or if you have a dedicated connection to the Internet either via Cable, DSL, T1, Satellite, etc. Click Next. 9. Type a host name, IP or any other description you would like to appear in the Network Connections area. You can change this later if you want. Click Next. 10. Type the host name or the Internet Protocol (IP) address of the computer that you want to connect to, and then click Next. 11. You may be asked if you want to use a Smart Card or not. 12. You are just about done, the rest of the screens just verify your connection, click Next. 13. Click to select the Add a shortcut to this connection to my desktop check box if you want one, if not, then leave it unchecked and click finish. 14. You are now done making your connection, but by default, it may try to connect. You can either try the connection now if you know its valid, if not, then just close it down for now. 15. In the Network Connections window, right-click the new connection and select properties. Let’s take a look at how you can customize this connection before it’s used. 16. The first tab you will see if the General Tab. This only covers the name of the connection, which you can also rename from the Network Connection dialog box by right clicking the connection and selecting to rename it. You can also configure a First connect, which means that Windows can connect the public network (like the Internet) before starting to attempt the ‘VPN’ connection. This is a perfect example as to when you would have configured the dialup connection; this would have been the first thing that you would have to do. It's simple, you have to be connected to the Internet first before you can encrypt and send data over it. This setting makes sure that this is a reality for you. 17. The next tab is the Options Tab. It is The Options tab has a lot you can configure in it. For one, you have the option to connect to a Windows Domain, if you select this check box (unchecked by default), then your VPN client will request Windows logon domain information while starting to work up the VPN connection. Also, you have options here for redialing. Redial attempts are configured here if you are using a dial up connection to get to the Internet. It is very handy to redial if the line is dropped as dropped lines are very common. 18. The next tab is the Security Tab. This is where you would configure basic security for the VPN client. This is where you would set any advanced IPSec configurations other security protocols as well as requiring encryption and credentials. 19. The next tab is the Networking Tab. This is where you can select what networking items are used by this VPN connection. 20. The Last tab is the Advanced Tab. This is where you can configure options for configuring a firewall, and/or sharing. Connecting to Corporate Now that you have your XP VPN client all set up and ready, the next step is to attempt a connection to the Remote Access or VPN server set up at the corporate office. To use the connection follow these simple steps. To open the client again, go back to the Network Connections dialog box. 1. One you are in the Network Connection dialog box, double-click, or right click and select ‘Connect’ from the menu – this will initiate the connection to the corporate office. 2. Type your user name and password, and then click Connect. Properties bring you back to what we just discussed in this article, all the global settings for the VPN client you are using. 3. To disconnect from a VPN connection, right-click the icon for the connection, and then click “Disconnect” Summary In this article we covered the basics of building a VPN connection using Windows XP. This is very handy when you have a VPN device but don’t have the ‘client’ that may come with it. If the VPN Server doesn’t use highly proprietary protocols, then you can use the XP client to connect with. In a future article I will get into the nuts and bolts of both IPSec and more detail on how to configure the advanced options in the Security tab of this client. 678: The remote computer did not respond. 930: The authentication server did not respond to authentication requests in a timely fashion. 800: Unable to establish the VPN connection. 623: The system could not find the phone book entry for this connection. 720: A connection to the remote computer could not be established. More on : http://www.windowsecurity.com/articles/Configure-VPN-Connection-Windows-XP.html

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  • C#/.NET Little Wonders: The Timeout static class

    - by James Michael Hare
    Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. When I started the “Little Wonders” series, I really wanted to pay homage to parts of the .NET Framework that are often small but can help in big ways.  The item I have to discuss today really is a very small item in the .NET BCL, but once again I feel it can help make the intention of code much clearer and thus is worthy of note. The Problem - Magic numbers aren’t very readable or maintainable In my first Little Wonders Post (Five Little Wonders That Make Code Better) I mention the TimeSpan factory methods which, I feel, really help the readability of constructed TimeSpan instances. Just to quickly recap that discussion, ask yourself what the TimeSpan specified in each case below is 1: // Five minutes? Five Seconds? 2: var fiveWhat1 = new TimeSpan(0, 0, 5); 3: var fiveWhat2 = new TimeSpan(0, 0, 5, 0); 4: var fiveWhat3 = new TimeSpan(0, 0, 5, 0, 0); You’d think they’d all be the same unit of time, right?  After all, most overloads tend to tack additional arguments on the end.  But this is not the case with TimeSpan, where the constructor forms are:     TimeSpan(int hours, int minutes, int seconds);     TimeSpan(int days, int hours, int minutes, int seconds);     TimeSpan(int days, int hours, int minutes, int seconds, int milliseconds); Notice how in the 4 and 5 parameter version we suddenly have the parameter days slipping in front of hours?  This can make reading constructors like those above much harder.  Fortunately, there are TimeSpan factory methods to help make your intention crystal clear: 1: // Ah! Much clearer! 2: var fiveSeconds = TimeSpan.FromSeconds(5); These are great because they remove all ambiguity from the reader!  So in short, magic numbers in constructors and methods can be ambiguous, and anything we can do to clean up the intention of the developer will make the code much easier to read and maintain. Timeout – Readable identifiers for infinite timeout values In a similar way to TimeSpan, let’s consider specifying timeouts for some of .NET’s (or our own) many methods that allow you to specify timeout periods. For example, in the TPL Task class, there is a family of Wait() methods that can take TimeSpan or int for timeouts.  Typically, if you want to specify an infinite timeout, you’d just call the version that doesn’t take a timeout parameter at all: 1: myTask.Wait(); // infinite wait But there are versions that take the int or TimeSpan for timeout as well: 1: // Wait for 100 ms 2: myTask.Wait(100); 3:  4: // Wait for 5 seconds 5: myTask.Wait(TimeSpan.FromSeconds(5); Now, if we want to specify an infinite timeout to wait on the Task, we could pass –1 (or a TimeSpan set to –1 ms), which what the .NET BCL methods with timeouts use to represent an infinite timeout: 1: // Also infinite timeouts, but harder to read/maintain 2: myTask.Wait(-1); 3: myTask.Wait(TimeSpan.FromMilliseconds(-1)); However, these are not as readable or maintainable.  If you were writing this code, you might make the mistake of thinking 0 or int.MaxValue was an infinite timeout, and you’d be incorrect.  Also, reading the code above it isn’t as clear that –1 is infinite unless you happen to know that is the specified behavior. To make the code like this easier to read and maintain, there is a static class called Timeout in the System.Threading namespace which contains definition for infinite timeouts specified as both int and TimeSpan forms: Timeout.Infinite An integer constant with a value of –1 Timeout.InfiniteTimeSpan A static readonly TimeSpan which represents –1 ms (only available in .NET 4.5+) This makes our calls to Task.Wait() (or any other calls with timeouts) much more clear: 1: // intention to wait indefinitely is quite clear now 2: myTask.Wait(Timeout.Infinite); 3: myTask.Wait(Timeout.InfiniteTimeSpan); But wait, you may say, why would we care at all?  Why not use the version of Wait() that takes no arguments?  Good question!  When you’re directly calling the method with an infinite timeout that’s what you’d most likely do, but what if you are just passing along a timeout specified by a caller from higher up?  Or perhaps storing a timeout value from a configuration file, and want to default it to infinite? For example, perhaps you are designing a communications module and want to be able to shutdown gracefully, but if you can’t gracefully finish in a specified amount of time you want to force the connection closed.  You could create a Shutdown() method in your class, and take a TimeSpan or an int for the amount of time to wait for a clean shutdown – perhaps waiting for client to acknowledge – before terminating the connection.  So, assume we had a pub/sub system with a class to broadcast messages: 1: // Some class to broadcast messages to connected clients 2: public class Broadcaster 3: { 4: // ... 5:  6: // Shutdown connection to clients, wait for ack back from clients 7: // until all acks received or timeout, whichever happens first 8: public void Shutdown(int timeout) 9: { 10: // Kick off a task here to send shutdown request to clients and wait 11: // for the task to finish below for the specified time... 12:  13: if (!shutdownTask.Wait(timeout)) 14: { 15: // If Wait() returns false, we timed out and task 16: // did not join in time. 17: } 18: } 19: } We could even add an overload to allow us to use TimeSpan instead of int, to give our callers the flexibility to specify timeouts either way: 1: // overload to allow them to specify Timeout in TimeSpan, would 2: // just call the int version passing in the TotalMilliseconds... 3: public void Shutdown(TimeSpan timeout) 4: { 5: Shutdown(timeout.TotalMilliseconds); 6: } Notice in case of this class, we don’t assume the caller wants infinite timeouts, we choose to rely on them to tell us how long to wait.  So now, if they choose an infinite timeout, they could use the –1, which is more cryptic, or use Timeout class to make the intention clear: 1: // shutdown the broadcaster, waiting until all clients ack back 2: // without timing out. 3: myBroadcaster.Shutdown(Timeout.Infinite); We could even add a default argument using the int parameter version so that specifying no arguments to Shutdown() assumes an infinite timeout: 1: // Modified original Shutdown() method to add a default of 2: // Timeout.Infinite, works because Timeout.Infinite is a compile 3: // time constant. 4: public void Shutdown(int timeout = Timeout.Infinite) 5: { 6: // same code as before 7: } Note that you can’t default the ShutDown(TimeSpan) overload with Timeout.InfiniteTimeSpan since it is not a compile-time constant.  The only acceptable default for a TimeSpan parameter would be default(TimeSpan) which is zero milliseconds, which specified no wait, not infinite wait. Summary While Timeout.Infinite and Timeout.InfiniteTimeSpan are not earth-shattering classes in terms of functionality, they do give you very handy and readable constant values that you can use in your programs to help increase readability and maintainability when specifying infinite timeouts for various timeouts in the BCL and your own applications. Technorati Tags: C#,CSharp,.NET,Little Wonders,Timeout,Task

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