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• NVIDIA x server - "sudo nvidia config" does not generate a working 'xorg.config'

  - by Mike

  I am over 18 hours deep on this challenge. I got to this point and am stuck. very stuck. Maybe you can figure it out? Ubuntu Version 12.04 LTS with all the updates installed. Problem: The default settings in "etc/X11/xorg.conf" that are generated by the "nvidia-xconfig" tool, do not allow the NVIDIA x server to connect to the driver in my "System Settings Additional Driver window". (that's how I understand it. Lots of information below). Symptoms of Problem "System Settings Additional Driver" window has drivers, but the nvidia x server cannot connect/utilize any of the 4 drivers. the drivers are activated, but not in use. When I go to "System Tools Administration NVIDIA x server settings" I get an error that basically tells me to create a default file to initialize the NVIDIA X server (screen shot below). This is the messages the terminal gives after running a "sudo nvidia-xconfig" command for the first time. It seems that the generated file by the tool i just ran is generating a bad/unusable file: If I run the "sudo nvidia-xconfig" command again, I wont get an error the second time. However when I reboot, the default file that is generated (etc/X11/xorg.conf) simply puts the screen resolution at 800 x 600 (or something big like that). When I try to go to NVIDIA x server settings I am greeted with the same screen as the screen shot as in symptom 2 (no option to change the resolution). If I try to go to "system settings display" there are no other resolutions to choose from. At this point I must delete the newly minted "xorg.conf" and reinstate the original in its place. Here are the contents of the "xorg.conf" that is generated first (the one missing required information): # nvidia-xconfig: X configuration file generated by nvidia-xconfig # nvidia-xconfig: version 304.88 (buildmeister@swio-display-x86-rhel47-06) Wed Mar 27 15:32:58 PDT 2013 Section "ServerLayout" Identifier "Layout0" Screen 0 "Screen0" InputDevice "Keyboard0" "CoreKeyboard" InputDevice "Mouse0" "CorePointer" EndSection Section "Files" EndSection Section "InputDevice" # generated from default Identifier "Mouse0" Driver "mouse" Option "Protocol" "auto" Option "Device" "/dev/psaux" Option "Emulate3Buttons" "no" Option "ZAxisMapping" "4 5" EndSection Section "InputDevice" # generated from default Identifier "Keyboard0" Driver "kbd" EndSection Section "Monitor" Identifier "Monitor0" VendorName "Unknown" ModelName "Unknown" HorizSync 28.0 - 33.0 VertRefresh 43.0 - 72.0 Option "DPMS" EndSection Section "Device" Identifier "Device0" Driver "nvidia" VendorName "NVIDIA Corporation" EndSection Section "Screen" Identifier "Screen0" Device "Device0" Monitor "Monitor0" DefaultDepth 24 SubSection "Display" Depth 24 EndSubSection EndSection Hardware: I ran the "lspci|grep VGA". There results are: 00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) 01:00.0 VGA compatible controller: NVIDIA Corporation GF108 [Quadro 1000M] (rev a1) More Hardware info: Ram: 16GB CPU: Intel Core i7-2720QM @2.2GHz * 8 Other: 64 bit. This is a triple boot computer and not a VM. Attempts With Not Success on My End: 1) Tried to append the "xorg.conf" with what I perceive is missing information and obviously it didn't fly. 2) All the other stuff I tried got me to this point. 3) See if this link is helpful to you (I barely get it, but i get enough knowing that a smarter person might find this useful): http://manpages.ubuntu.com/manpages/lucid/man1/nvidia-xconfig.1.html 4) I am completely new to Linux (40 hours over past week), but not to programming. However I am very serious about changing over to Linux. When you respond (I hope someone responds...) please respond in a way that a person new to Linux can understand. 5) By the way, the reason I am in this mess is because I MUST have a second monitor running from my laptop, and "System Settings Display" doesn't recognize my second display. I know it is possible to make the second display work in my system, because when I boot from the install CD, I perform work on the native laptop monitor, but the second monitor shows a purple screen with Ubuntu in the middle, so I know the VGA port is sending a signal out. If this is too much for you to tackle please suggest an alternative method to get a second display. I don't want to go to windows but I cannot have a single display. I am really fudged here. I hope some smart person can help. Thanks in advance. Mike. **********************EDIT #1********************** More Details About Graphics Card I was asked "which brand of nvidia-card do you have exactly?" Here is what I did to provide more info (maybe relevant, maybe not, but here is everything): 1) Took my Lenovo W520 right apart to see if there is an identifier on the actual card. However I realized that if I get deep enough to take a look, the laptop "won't like it". so I put it back together. Figuring out the card this way is not an option for me right now. 2) (My computer is triple boot) I logged into Win7 and ran 'dxdiag' command. here is the screen shot: 3) I tried to look on the lenovo website for more details... but no luck. I took a look at my receipts and here is info form receipt: System Unit: W520 NVIDIA Quadro 1000M 2GB 4) In win7 I went to the NVIDIA website and used the option to have my card 'scanned' by a Java applet to determine the latest update for my card. I tried the same with Ubuntu but I can't get the applet to run. Here is the recommended driver from from the NVIDIA Applet for my card for Win7 (I hope this shines some light on the specifics of the card): Quadro/NVS/Tesla/GRID Desktop Driver Release R319 Version: 320.00 WHQL Release Date: 3.5.2013 5) Also I went on the NVIDIA driver search and looked through every possible combination of product type + product series + product to find all the combinations that yield a 1000M card. My card is: Product Type: Quadro Product Series: Quadro Series (Notebooks) Product: 1000M ***********************EDIT #2******************* Additional Symptoms Another question that generated more symptoms I previously didn't mention was: "After generating xorg.conf by nvidia-xconfig, go to additional drivers, do you see nvidia-304?" 1) I took a screen shot of the "additional drivers" right after generating xorg.conf by nvidia-xconfig. Here it is: 2) Then I did a reboot. Now Ubuntu is 600 x 800 resolution. When I logged in after the computer came up I got an error (which I always get after generating xorg.conf by nvidia-xconfig and rebooting) 3) To finally answer the question - No. There is no "NVIDIA-304" driver. Screen shot of additional drivers after generating xorg.conf by nvidia-xconfig and rebooting : At this point I revert to the original xorg.conf and delete the xorg.conf generated by Nvidia.

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• What Makes a Good Design Critic? CHI 2010 Panel Review

  - by Applications User Experience

  Author: Daniel Schwartz, Senior Interaction Designer, Oracle Applications User Experience Oracle Applications UX Chief Evangelist Patanjali Venkatacharya organized and moderated an innovative and stimulating panel discussion titled "What Makes a Good Design Critic? Food Design vs. Product Design Criticism" at CHI 2010, the annual ACM Conference on Human Factors in Computing Systems. The panelists included Janice Rohn, VP of User Experience at Experian; Tami Hardeman, a food stylist; Ed Seiber, a restaurant architect and designer; Jonathan Kessler, a food critic and writer at the Atlanta Journal-Constitution; and Larry Powers, Chef de Cuisine at Shaun's restaurant in Atlanta, Georgia. Building off the momentum of his highly acclaimed panel at CHI 2009 on what interaction design can learn from food design (for which I was on the other side as a panelist), Venkatacharya brought together new people with different roles in the restaurant and software interaction design fields. The session was also quite delicious -- but more on that later. Criticism, as it applies to food and product or interaction design, was the tasty topic for this forum and showed that strong parallels exist between food and interaction design criticism. Figure 1. The panelists in discussion: (left to right) Janice Rohn, Ed Seiber, Tami Hardeman, and Jonathan Kessler. The panelists had great insights to share from their respective fields, and they enthusiastically discussed as if they were at a casual collegial dinner. Jonathan Kessler stated that he prefers to have one professional critic's opinion in general than a large sampling of customers, however, "Web sites like Yelp get users excited by the collective approach. People are attracted to things desired by so many." Janice Rohn added that this collective desire was especially true for users of consumer products. Ed Seiber remarked that while people looked to the popular view for their target tastes and product choices, "professional critics like John [Kessler] still hold a big weight on public opinion." Chef Powers indicated that chefs take in feedback from all sources, adding, "word of mouth is very powerful. We also look heavily at the sales of the dishes to see what's moving; what's selling and thus successful." Hearing this discussion validates our design work at Oracle in that we listen to our users (our diners) and industry feedback (our critics) to ensure an optimal user experience of our products. Rohn considers that restaurateur Danny Meyer's book, Setting the Table: The Transforming Power of Hospitality in Business, which is about creating successful restaurant experiences, has many applicable parallels to user experience design. Meyer actually argues that the customer is not always right, but that "they must always feel heard." Seiber agreed, but noted "customers are not designers," and while designers need to listen to customer feedback, it is the designer's job to synthesize it. Seiber feels it's the critic's job to point out when something is missing or not well-prioritized. In interaction design, our challenges are quite similar, if not parallel. Software tasks are like puzzles that are in search of a solution on how to be best completed. As a food stylist, Tami Hardeman has the demanding and challenging task of presenting food to be as delectable as can be. To present food in its best light requires a lot of creativity and insight into consumer tastes. It's no doubt then that this former fashion stylist came up with the ultimate catch phrase to capture the emotion that clients want to draw from their users: "craveability." The phrase was a hit with the audience and panelists alike. Sometime later in the discussion, Seiber remarked, "designers strive to apply craveability to products, and I do so for restaurants in my case." Craveabilty is also very applicable to interaction design. Creating straightforward and smooth workflows for users of Oracle Applications is a primary goal for my colleagues. We want our users to really enjoy working with our products where it makes them more efficient and better at their jobs. That's our "craveability." Patanjali Venkatacharya asked the panel, "if a design's "craveability" appeals to some cultures but not to others, then what is the impact to the food or product design process?" Rohn stated that "taste is part nature and part nurture" and that the design must take the full context of a product's usage into consideration. Kessler added, "good design is about understanding the context" that the experience necessitates. Seiber remarked how important seat comfort is for diners and how the quality of seating will add so much to the complete dining experience. Sometimes if these non-food factors are not well executed, they can also take away from an otherwise pleasant dining experience. Kessler recounted a time when he was dining at a restaurant that actually had very good food, but the photographs hanging on all the walls did not fit in with the overall décor and created a negative overall dining experience. While the tastiness of the food is critical to a restaurant's success, it is a captivating complete user experience, as in interaction design, which will keep customers coming back and ultimately making the restaurant a hit. Figure 2. Patnajali Venkatacharya enjoyed the Sardian flatbread salad. As a surprise Chef Powers brought out a signature dish from Shaun's restaurant for all the panelists to sample and critique. The Sardinian flatbread dish showcased Atlanta's taste for fresh and local produce and cheese at its finest as a salad served on a crispy flavorful flat bread. Hardeman said it could be photographed from any angle, a high compliment coming from a food stylist. Seiber really enjoyed the colors that the dish brought together and thought it would be served very well in a casual restaurant on a summer's day. The panel really appreciated the taste and quality of the different components and how the rosemary brought all the flavors together. Seiber remarked that "a lot of effort goes into the appearance of simplicity." Rohn indicated that the same notion holds true with software user interface design. A tremendous amount of work goes into crafting straightforward interfaces, including user research, prototyping, design iterations, and usability studies. Design criticism for food and software interfaces clearly share many similarities. Both areas value expert opinions and user feedback. Both areas understand the importance of great design needing to work well in its context. Last but not least, both food and interaction design criticism value "craveability" and how having users excited about experiencing and enjoying the designs is an important goal. Now if we can just improve the taste of software user interfaces, people may choose to dine on their enterprise applications over a fresh organic salad.

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• Guide to MySQL & NoSQL, Webinar Q&A

  - by Mat Keep

  0 0 1 959 5469 Homework 45 12 6416 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Cambria; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-ansi-language:EN-US;} Yesterday we ran a webinar discussing the demands of next generation web services and how blending the best of relational and NoSQL technologies enables developers and architects to deliver the agility, performance and availability needed to be successful. Attendees posted a number of great questions to the MySQL developers, serving to provide additional insights into areas like auto-sharding and cross-shard JOINs, replication, performance, client libraries, etc. So I thought it would be useful to post those below, for the benefit of those unable to attend the webinar. Before getting to the Q&A, there are a couple of other resources that maybe useful to those looking at NoSQL capabilities within MySQL: - On-Demand webinar (coming soon!) - Slides used during the webinar - Guide to MySQL and NoSQL whitepaper  - MySQL Cluster demo, including NoSQL interfaces, auto-sharing, high availability, etc.  So here is the Q&A from the event  Q. Where does MySQL Cluster fit in to the CAP theorem? A. MySQL Cluster is flexible. A single Cluster will prefer consistency over availability in the presence of network partitions. A pair of Clusters can be configured to prefer availability over consistency. A full explanation can be found on the MySQL Cluster & CAP Theorem blog post.  Q. Can you configure the number of replicas? (the slide used a replication factor of 1) Yes. A cluster is configured by an .ini file. The option NoOfReplicas sets the number of originals and replicas: 1 = no data redundancy, 2 = one copy etc. Usually there's no benefit in setting it >2. Q. Interestingly most (if not all) of the NoSQL databases recommend having 3 copies of data (the replication factor).    Yes, with configurable quorum based Reads and writes. MySQL Cluster does not need a quorum of replicas online to provide service. Systems that require a quorum need > 2 replicas to be able to tolerate a single failure. Additionally, many NoSQL systems take liberal inspiration from the original GFS paper which described a 3 replica configuration. MySQL Cluster avoids the need for a quorum by using a lightweight arbitrator. You can configure more than 2 replicas, but this is a tradeoff between incrementally improved availability, and linearly increased cost. Q. Can you have cross node group JOINS? Wouldn't that run into the risk of flooding the network? MySQL Cluster 7.2 supports cross nodegroup joins. A full cross-join can require a large amount of data transfer, which may bottleneck on network bandwidth. However, for more selective joins, typically seen with OLTP and light analytic applications, cross node-group joins give a great performance boost and network bandwidth saving over having the MySQL Server perform the join. Q. Are the details of the benchmark available anywhere? According to my calculations it results in approx. 350k ops/sec per processor which is the largest number I've seen lately The details are linked from Mikael Ronstrom's blog The benchmark uses a benchmarking tool we call flexAsynch which runs parallel asynchronous transactions. It involved 100 byte reads, of 25 columns each. Regarding the per-processor ops/s, MySQL Cluster is particularly efficient in terms of throughput/node. It uses lock-free minimal copy message passing internally, and maximizes ID cache reuse. Note also that these are in-memory tables, there is no need to read anything from disk. Q. Is access control (like table) planned to be supported for NoSQL access mode? Currently we have not seen much need for full SQL-like access control (which has always been overkill for web apps and telco apps). So we have no plans, though especially with memcached it is certainly possible to turn-on connection-level access control. But specifically table level controls are not planned. Q. How is the performance of memcached APi with MySQL against memcached+MySQL or any other Object Cache like Ecache with MySQL DB? With the memcache API we generally see a memcached response in less than 1 ms. and a small cluster with one memcached server can handle tens of thousands of operations per second. Q. Can .NET can access MemcachedAPI? Yes, just use a .Net memcache client such as the enyim or BeIT memcache libraries. Q. Is the row level locking applicable when you update a column through memcached API? An update that comes through memcached uses a row lock and then releases it immediately. Memcached operations like "INCREMENT" are actually pushed down to the data nodes. In most cases the locks are not even held long enough for a network round trip. Q. Has anyone published an example using something like PHP? I am assuming that you just use the PHP memcached extension to hook into the memcached API. Is that correct? Not that I'm aware of but absolutely you can use it with php or any of the other drivers Q. For beginner we need more examples. Take a look here for a fully worked example Q. Can I access MySQL using Cobol (Open Cobol) or C and if so where can I find the coding libraries etc? A. There is a cobol implementation that works well with MySQL, but I do not think it is Open Cobol. Also there is a MySQL C client library that is a standard part of every mysql distribution Q. Is there a place to go to find help when testing and/implementing the NoSQL access? If using Cluster then you can use the [email protected] alias or post on the MySQL Cluster forum Q. Are there any white papers on this?  Yes - there is more detail in the MySQL Guide to NoSQL whitepaper If you have further questions, please don’t hesitate to use the comments below!

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• Small adventure game

  - by Nick Rosencrantz

  I'm making a small adventure game where the player can walk through Dungeons and meet scary characters: The whole thing is 20 java classes and I'm making this a standalone frame while it could very well be an applet I don't want to make another applet since I might want to recode this in C/C++ if the game or game engine turns out a success. The engine is the most interesting part of the game, it controls players and computer-controlled characters such as Zombies, Reptile Warriors, Trolls, Necromancers, and other Persons. These persons can sleep or walk around in the game and also pick up and move things. I didn't add many things so I suppose that is the next thing to do is to add things that can get used now that I already added many different types of walking persons. What do you think I should add and do with things in the game? The things I have so far is: package adventure; /** * The data type for things. Subclasses will be create that takes part of the story */ public class Thing { /** * The name of the Thing. */ public String name; /** * @param name The name of the Thing. */ Thing( String name ) { this.name = name; } } public class Scroll extends Thing { Scroll (String name) { super(name); } } class Key extends Thing { Key (String name) { super(name); } } The key is the way to win the game if you figure our that you should give it to a certain person and the scroll can protect you from necromancers and trolls. If I make this game more Dungeons and Dragons-inspired, do you think will be any good? Any other ideas that you think I could use here? The Threadwhich steps time forward and wakes up persons is called simulation. Do you think I could do something more advanced with this class? package adventure; class Simulation extends Thread { private PriorityQueue Eventqueue; Simulation() { Eventqueue = new PriorityQueue(); start(); } public void wakeMeAfter(Wakeable SleepingObject, double time) { Eventqueue.enqueue(SleepingObject, System.currentTimeMillis()+time); } public void run() { while(true) { try { sleep(5); //Sov i en halv sekund if (Eventqueue.getFirstTime() <= System.currentTimeMillis()) { ((Wakeable)Eventqueue.getFirst()).wakeup(); Eventqueue.dequeue(); } } catch (InterruptedException e ) { } } } } And here is the class that makes up the actual world: package adventure; import java.awt.*; import java.net.URL; /** * Subklass to World that builds up the Dungeon World. */ public class DungeonWorld extends World { /** * * @param a Reference to adventure game. * */ public DungeonWorld(Adventure a) { super ( a ); // Create all places createPlace( "Himlen" ); createPlace( "Stairs3" ); createPlace( "IPLab" ); createPlace( "Dungeon3" ); createPlace( "Stairs5" ); createPlace( "C2M2" ); createPlace( "SANS" ); createPlace( "Macsal" ); createPlace( "Stairs4" ); createPlace( "Dungeon2" ); createPlace( "Datorsalen" ); createPlace( "Dungeon");//, "Ljushallen.gif" ); createPlace( "Cola-automaten", "ColaAutomat.gif" ); createPlace( "Stairs2" ); createPlace( "Fable1" ); createPlace( "Dungeon1" ); createPlace( "Kulverten" ); // Create all connections between places connect( "Stairs3", "Stairs5", "Down", "Up" ); connect( "Dungeon3", "SANS", "Down", "Up" ); connect( "Dungeon3", "IPLab", "West", "East" ); connect( "IPLab", "Stairs3", "West", "East" ); connect( "Stairs5", "Stairs4", "Down", "Up" ); connect( "Macsal", "Stairs5", "South", "Norr" ); connect( "C2M2", "Stairs5", "West", "East" ); connect( "SANS", "C2M2", "West", "East" ); connect( "Stairs4", "Dungeon", "Down", "Up" ); connect( "Datorsalen", "Stairs4", "South", "Noth" ); connect( "Dungeon2", "Stairs4", "West", "East" ); connect( "Dungeon", "Stairs2", "Down", "Up" ); connect( "Dungeon", "Cola-automaten", "South", "North" ); connect( "Stairs2", "Kulverten", "Down", "Up" ); connect( "Stairs2", "Fable1", "East", "West" ); connect( "Fable1", "Dungeon1", "South", "North" ); // Add things // --- Add new things here --- getPlace("Cola-automaten").addThing(new CocaCola("Ljummen cola")); getPlace("Cola-automaten").addThing(new CocaCola("Avslagen Cola")); getPlace("Cola-automaten").addThing(new CocaCola("Iskall Cola")); getPlace("Cola-automaten").addThing(new CocaCola("Cola Light")); getPlace("Cola-automaten").addThing(new CocaCola("Cuba Cola")); getPlace("Stairs4").addThing(new Scroll("Scroll")); getPlace("Dungeon3").addThing(new Key("Key")); Simulation sim = new Simulation(); // Load images to be used as appearance-parameter for persons Image studAppearance = owner.loadPicture( "Person.gif" ); Image asseAppearance = owner.loadPicture( "Asse.gif" ); Image trollAppearance = owner.loadPicture( "Loke.gif" ); Image necromancerAppearance = owner.loadPicture( "Necromancer.gif" ); Image skeletonAppearance = owner.loadPicture( "Reptilewarrior.gif" ); Image reptileAppearance = owner.loadPicture( "Skeleton.gif" ); Image zombieAppearance = owner.loadPicture( "Zombie.gif" ); // --- Add new persons here --- new WalkingPerson(sim, this, "Peter", studAppearance); new WalkingPerson(sim, this, "Zombie", zombieAppearance ); new WalkingPerson(sim, this, "Zombie", zombieAppearance ); new WalkingPerson(sim, this, "Skeleton", skeletonAppearance ); new WalkingPerson(sim, this, "John", studAppearance ); new WalkingPerson(sim, this, "Skeleton", skeletonAppearance ); new WalkingPerson(sim, this, "Skeleton", skeletonAppearance ); new WalkingPerson(sim, this, "Skeleton", skeletonAppearance ); new WalkingPerson(sim, this, "Sean", studAppearance ); new WalkingPerson(sim, this, "Reptile", reptileAppearance ); new LabAssistant(sim, this, "Kate", asseAppearance); new LabAssistant(sim, this, "Jenna", asseAppearance); new Troll(sim, this, "Troll", trollAppearance); new Necromancer(sim, this, "Necromancer", necromancerAppearance); } /** * * The place where persons are placed by default * *@return The default place. * */ public Place defaultPlace() { return getPlace( "Datorsalen" ); } private void connect( String p1, String p2, String door1, String door2) { Place place1 = getPlace( p1 ); Place place2 = getPlace( p2 ); place1.addExit( door1, place2 ); place2.addExit( door2, place1 ); } } Thanks

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• DBCC CHECKDB on VVLDB and latches (Or: My Pain is Your Gain)

  - by Argenis

    Does your CHECKDB hurt, Argenis? There is a classic blog series by Paul Randal [blog|twitter] called “CHECKDB From Every Angle” which is pretty much mandatory reading for anybody who’s even remotely considering going for the MCM certification, or its replacement (the Microsoft Certified Solutions Master: Data Platform – makes my fingers hurt just from typing it). Of particular interest is the post “Consistency Options for a VLDB” – on it, Paul provides solid, timeless advice (I use the word “timeless” because it was written in 2007, and it all applies today!) on how to perform checks on very large databases. Well, here I was trying to figure out how to make CHECKDB run faster on a restored copy of one of our databases, which happens to exceed 7TB in size. The whole thing was taking several days on multiple systems, regardless of the storage used – SAS, SATA or even SSD…and I actually didn’t pay much attention to how long it was taking, or even bothered to look at the reasons why - as long as it was finishing okay and found no consistency errors. Yes – I know. That was a huge mistake, as corruption found in a database several days after taking place could only allow for further spread of the corruption – and potentially large data loss. In the last two weeks I increased my attention towards this problem, as we noticed that CHECKDB was taking EVEN LONGER on brand new all-flash storage in the SAN! I couldn’t really explain it, and were almost ready to blame the storage vendor. The vendor told us that they could initially see the server driving decent I/O – around 450Mb/sec, and then it would settle at a very slow rate of 10Mb/sec or so. “Hum”, I thought – “CHECKDB is just not pushing the I/O subsystem hard enough”. Perfmon confirmed the vendor’s observations. Dreaded @BlobEater What was CHECKDB doing all the time while doing so little I/O? Eating Blobs. It turns out that CHECKDB was taking an extremely long time on one of our frankentables, which happens to be have 35 billion rows (yup, with a b) and sucks up several terabytes of space in the database. We do have a project ongoing to purge/split/partition this table, so it’s just a matter of time before we deal with it. But the reality today is that CHECKDB is coming to a screeching halt in performance when dealing with this particular table. Checking sys.dm_os_waiting_tasks and sys.dm_os_latch_stats showed that LATCH_EX (DBCC_OBJECT_METADATA) was by far the top wait type. I remembered hearing recently about that wait from another post that Paul Randal made, but that was related to computed-column indexes, and in fact, Paul himself reminded me of his article via twitter. But alas, our pathologic table had no non-clustered indexes on computed columns. I knew that latches are used by the database engine to do internal synchronization – but how could I help speed this up? After all, this is stuff that doesn’t have a lot of knobs to tweak. (There’s a fantastic level 500 talk by Bob Ward from Microsoft CSS [blog|twitter] called “Inside SQL Server Latches” given at PASS 2010 – and you can check it out here. DISCLAIMER: I assume no responsibility for any brain melting that might ensue from watching Bob’s talk!) Failed Hypotheses Earlier on this week I flew down to Palo Alto, CA, to visit our Headquarters – and after having a great time with my Monkey peers, I was relaxing on the plane back to Seattle watching a great talk by SQL Server MVP and fellow MCM Maciej Pilecki [twitter] called “Masterclass: A Day in the Life of a Database Transaction” where he discusses many different topics related to transaction management inside SQL Server. Very good stuff, and when I got home it was a little late – that slow DBCC CHECKDB that I had been dealing with was way in the back of my head. As I was looking at the problem at hand earlier on this week, I thought “How about I set the database to read-only?” I remembered one of the things Maciej had (jokingly) said in his talk: “if you don’t want locking and blocking, set the database to read-only” (or something to that effect, pardon my loose memory). I immediately killed the CHECKDB which had been running painfully for days, and set the database to read-only mode. Then I ran DBCC CHECKDB against it. It started going really fast (even a bit faster than before), and then throttled down again to around 10Mb/sec. All sorts of expletives went through my head at the time. Sure enough, the same latching scenario was present. Oh well. I even spent some time trying to figure out if NUMA was hurting performance. Folks on Twitter made suggestions in this regard (thanks, Lonny! [twitter]) …Eureka? This past Friday I was still scratching my head about the whole thing; I was ready to start profiling with XPERF to see if I could figure out which part of the engine was to blame and then get Microsoft to look at the evidence. After getting a bunch of good news I’ll blog about separately, I sat down for a figurative smack down with CHECKDB before the weekend. And then the light bulb went on. A sparse column. I thought that I couldn’t possibly be experiencing the same scenario that Paul blogged about back in March showing extreme latching with non-clustered indexes on computed columns. Did I even have a non-clustered index on my sparse column? As it turns out, I did. I had one filtered non-clustered index – with the sparse column as the index key (and only column). To prove that this was the problem, I went and setup a test. Yup, that'll do it The repro is very simple for this issue: I tested it on the latest public builds of SQL Server 2008 R2 SP2 (CU6) and SQL Server 2012 SP1 (CU4). First, create a test database and a test table, which only needs to contain a sparse column: CREATE DATABASE SparseColTest; GO USE SparseColTest; GO CREATE TABLE testTable (testCol smalldatetime SPARSE NULL); GO INSERT INTO testTable (testCol) VALUES (NULL); GO 1000000 That’s 1 million rows, and even though you’re inserting NULLs, that’s going to take a while. In my laptop, it took 3 minutes and 31 seconds. Next, we run DBCC CHECKDB against the database: DBCC CHECKDB('SparseColTest') WITH NO_INFOMSGS, ALL_ERRORMSGS; This runs extremely fast, as least on my test rig – 198 milliseconds. Now let’s create a filtered non-clustered index on the sparse column: CREATE NONCLUSTERED INDEX [badBadIndex] ON testTable (testCol) WHERE testCol IS NOT NULL; With the index in place now, let’s run DBCC CHECKDB one more time: DBCC CHECKDB('SparseColTest') WITH NO_INFOMSGS, ALL_ERRORMSGS; In my test system this statement completed in 11433 milliseconds. 11.43 full seconds. Quite the jump from 198 milliseconds. I went ahead and dropped the filtered non-clustered indexes on the restored copy of our production database, and ran CHECKDB against that. We went down from 7+ days to 19 hours and 20 minutes. Cue the “Argenis is not impressed” meme, please, Mr. LaRock. My pain is your gain, folks. Go check to see if you have any of such indexes – they’re likely causing your consistency checks to run very, very slow. Happy CHECKDBing, -Argenis ps: I plan to file a Connect item for this issue – I consider it a pretty serious bug in the engine. After all, filtered indexes were invented BECAUSE of the sparse column feature – and it makes a lot of sense to use them together. Watch this space and my twitter timeline for a link.

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• Personal Technology – Laptop Screen Blank – No Post – No BIOS – No Boot

  - by Pinal Dave

  If your laptop Screen is Blank and there is no POST, BIOS or boot, you can follow the steps mentioned here and there are chances that it will work if there is no hardware failure inside. Step 1: Remove the power cord from the laptop Step 2: Remove the battery from the laptop Step 3: Hold power button (keep it pressed) for almost 60 seconds Step 4: Plug power back in laptop Step 5: Start computer and it should just start normally. Step 6: Now shut down Step 7: Insert the battery back in the laptop Step 8: Start laptop again and it should work Note 1: If your laptop does not work after inserting back the memory. Remove the memory and repeat above process. Do not insert the battery back as it is malfunctioning. Note 2: If your screen is faulty or have issues with your hardware (motherboard, screen or anything else) this method will not fix your computer. Those, who care about how I come up with this not SQL related blog post, here is the very funny true story. If you are a married man, you will know what I am going to describe next. May be you have faced the same situation or at least you feel and understand my situation. My wife’s computer suddenly stops working when she was searching for my daughter’s mathematics worksheets online. While the fatal accident happened with my wife’s computer (which was my loyal computer for over 4 years before she got it), I was working in my home office, fixing a high priority issue (live order’s database was corrupted) with one of the largest eCommerce websites.  While I was working on production server where I was fixing database corruption, my wife ran to my home office. Here is how the conversation went: Wife: This computer does not work. I: Restart it. Wife: It does not start. I: What did you do with it? Wife: Nothing, it just stopped working. I: Okey, I will look into it later, working on the very urgent issue. Wife: I was printing my daughter’s worksheet. I: Hm.. Okey. Wife: It was the mathematics worksheet, which you promised you will teach but you never get around to do it, so I am doing it myself. I: Thanks. I appreciate it. I am very busy with this issue as million dollar transaction are not happening as the database got corrupted and … Wife: So what … umm… You mean to say that you care about this customer more than your daughter. You know she got A+ in every other class but in mathematics she got only A. She missed that extra credit question. I: She is only 4, it is okay. Wife: She is 4.5 years old not 4. So you are not going to fix this computer which does not start at all. I think our daughter next time will even get lower grades as her dad is busy fixing something. I: Alright, I give up bring me that computer. Our daughter who was listening everything so far she finally decided to speak up. Daughter: Dad, it is a laptop not computer. I: Yes, sweety get that laptop here and your dad is going to fix the this small issue of million dollar issue later on. I decided to pay attention to my wife’s computer. She was right. No matter what I do, it will not boot up, it will not start, no BIOS, no POST screen. The computer starts for a second but nothing comes up on the screen. The light indicating hard drive comes up for a second and goes off. Nothing happens. I removed every single USB drive from the laptop but it still would not start. It was indeed no fun for me. Finally I remember my days when I was not married and used to study in University of Southern California, Los Angeles. I remembered that I used to have very old second (or maybe third or fourth) hand computer with me. In polite words, I had pre-owned computer and it used to face very similar issues again and again. I had small routine I used to follow to fix my old computer and I had decided to follow the same steps again with this computer. Step 1: Remove the power cord from the laptop Step 2: Remove the battery from the laptop Step 3: Hold power button (keep it pressed) for almost 60 seconds Step 4: Plug power back in laptop Step 5: Start computer and it should just start normally. Step 6: Now shut down Step 7: Insert the battery back in the laptop Step 8: Start laptop again and it should work Note 1: If your laptop does not work after inserting back the memory. Remove the memory and repeat above process. Do not insert the battery back as it is malfunctioning. Note 2: If your screen is faulty or have issues with your hardware (motherboard, screen or anything else) this method will not fix your computer. Once I followed above process, her computer worked. I was very delighted, that now I can go back to solving the problem where millions of transactions were waiting as I was fixing corrupted database and it the current state of the database was in emergency mode. Once I fixed the computer, I looked at my wife and asked. I: Well, now this laptop is back online, can I get guaranteed that she will get A+ in mathematics in this week’s quiz? Wife: Sure, I promise. I: Fantastic. After saying that I started to look at my database corruption and my wife interrupted me again. Wife: Btw, I forgot to tell you. Our daughter had got A in mathematics last week but she had another quiz today and she already have received A+ there. I kept my promise. I looked at her and she started to walk outside room, before I say anything my phone rang. DBA from eCommerce company had called me, as he was wondering why there is no activity from my side in last 10 minutes. DBA: Hey bud, are you still connected. I see um… no activity in last 10 minutes. I: Oh, well, I was just saving the world. I am back now. After two hours I had fixed the database corruption and everything was normal. I was outsmarted by my wife but honestly I still respect and love her the same as she is the one who spends countless hours with our daughter so she does not miss me and I can continue writing blogs and keep on doing technology evangelism. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Humor, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Source-control 'wet-work'?

  - by Phil Factor

  When a design or creative work is flawed beyond remedy, it is often best to destroy it and start again. The other day, I lost the code to a long and intricate SQL batch I was working on. I’d thought it was impossible, but it happened. With all the technology around that is designed to prevent this occurring, this sort of accident has become a rare event.  If it weren’t for a deranged laptop, and my distraction, the code wouldn’t have been lost this time.  As always, I sighed, had a soothing cup of tea, and typed it all in again.  The new code I hastily tapped in  was much better: I’d held in my head the essence of how the code should work rather than the details: I now knew for certain  the start point, the end, and how it should be achieved. Instantly the detritus of half-baked thoughts fell away and I was able to write logical code that performed better.  Because I could work so quickly, I was able to hold the details of all the columns and variables in my head, and the dynamics of the flow of data. It was, in fact, easier and quicker to start from scratch rather than tidy up and refactor the existing code with its inevitable fumbling and half-baked ideas. What a shame that technology is now so good that developers rarely experience the cleansing shock of losing one’s code and having to rewrite it from scratch.  If you’ve never accidentally lost  your code, then it is worth doing it deliberately once for the experience. Creative people have, until Technology mistakenly prevented it, torn up their drafts or sketches, threw them in the bin, and started again from scratch.  Leonardo’s obsessive reworking of the Mona Lisa was renowned because it was so unusual:  Most artists have been utterly ruthless in destroying work that didn’t quite make it. Authors are particularly keen on writing afresh, and the results are generally positive. Lawrence of Arabia actually lost the entire 250,000 word manuscript of ‘The Seven Pillars of Wisdom’ by accidentally leaving it on a train at Reading station, before rewriting a much better version.  Now, any writer or artist is seduced by technology into altering or refining their work rather than casting it dramatically in the bin or setting a light to it on a bonfire, and rewriting it from the blank page.  It is easy to pick away at a flawed work, but the real creative process is far more brutal. Once, many years ago whilst running a software house that supplied commercial software to local businesses, I’d been supervising an accounting system for a farming cooperative. No packaged system met their needs, and it was all hand-cut code.  For us, it represented a breakthrough as it was for a government organisation, and success would guarantee more contracts. As you’ve probably guessed, the code got mangled in a disk crash just a week before the deadline for delivery, and the many backups all proved to be entirely corrupted by a faulty tape drive.  There were some fragments left on individual machines, but they were all of different versions.  The developers were in despair.  Strangely, I managed to re-write the bulk of a three-month project in a manic and caffeine-soaked weekend.  Sure, that elegant universally-applicable input-form routine was‘nt quite so elegant, but it didn’t really need to be as we knew what forms it needed to support.  Yes, the code lacked architectural elegance and reusability. By dawn on Monday, the application passed its integration tests. The developers rose to the occasion after I’d collapsed, and tidied up what I’d done, though they were reproachful that some of the style and elegance had gone out of the application. By the delivery date, we were able to install it. It was a smaller, faster application than the beta they’d seen and the user-interface had a new, rather Spartan, appearance that we swore was done to conform to the latest in user-interface guidelines. (we switched to Helvetica font to look more ‘Bauhaus’ ). The client was so delighted that he forgave the new bugs that had crept in. I still have the disk that crashed, up in the attic. In IT, we have had mixed experiences from complete re-writes. Lotus 123 never really recovered from a complete rewrite from assembler into C, Borland made the mistake with Arago and Quattro Pro  and Netscape’s complete rewrite of their Navigator 4 browser was a white-knuckle ride. In all cases, the decision to rewrite was a result of extreme circumstances where no other course of action seemed possible.   The rewrite didn’t come out of the blue. I prefer to remember the rewrite of Minix by young Linus Torvalds, or the rewrite of Bitkeeper by a slightly older Linus.  The rewrite of CP/M didn’t do too badly either, did it? Come to think of it, the guy who decided to rewrite the windowing system of the Xerox Star never regretted the decision. I’ll agree that one should often resist calls for a rewrite. One of the worst habits of the more inexperienced programmer is to denigrate whatever code he or she inherits, and then call loudly for a complete rewrite. They are buoyed up by the mistaken belief that they can do better. This, however, is a different psychological phenomenon, more related to the idea of some motorcyclists that they are operating on infinite lives, or the occasional squaddies that if they charge the machine-guns determinedly enough all will be well. Grim experience brings out the humility in any experienced programmer.  I’m referring to quite different circumstances here. Where a team knows the requirements perfectly, are of one mind on methodology and coding standards, and they already have a solution, then what is wrong with considering  a complete rewrite? Rewrites are so painful in the early stages, until that point where one realises the payoff, that even I quail at the thought. One needs a natural disaster to push one over the edge. The trouble is that source-control systems, and disaster recovery systems, are just too good nowadays.   If I were to lose this draft of this very blog post, I know I’d rewrite it much better. However, if you read this, you’ll know I didn’t have the nerve to delete it and start again.  There was a time that one prayed that unreliable hardware would deliver you from an unmaintainable mess of a codebase, but now technology has made us almost entirely immune to such a merciful act of God. An old friend of mine with long experience in the software industry has long had the idea of the ‘source-control wet-work’,  where one hires a malicious hacker in some wild eastern country to hack into one’s own  source control system to destroy all trace of the source to an application. Alas, backup systems are just too good to make this any more than a pipedream. Somehow, it would be difficult to promote the idea. As an alternative, could one construct a source control system that, on doing all the code-quality metrics, would systematically destroy all trace of source code that failed the quality test? Alas, I can’t see many managers buying into the idea. In reading the full story of the near-loss of Toy Story 2, it set me thinking. It turned out that the lucky restoration of the code wasn’t the happy ending one first imagined it to be, because they eventually came to the conclusion that the plot was fundamentally flawed and it all had to be rewritten anyway.  Was this an early  case of the ‘source-control wet-job’?’ It is very hard nowadays to do a rapid U-turn in a development project because we are far too prone to cling to our existing source-code.

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• How to Never Use iTunes With Your iPhone, iPad, or iPod Touch

  - by Chris Hoffman

  iTunes isn’t an amazing program on Windows. There was a time when Apple device users had to plug their devices into their PCs or Macs and use iTunes for device activation, updates, and syncing, but iTunes is no longer necessary. Apple still allows you to use iTunes for these things, but you don’t have to. Your iOS device can function independently from iTunes, so you should never be forced to plug it into a PC or Mac. Device Activation When the iPad first came out, it was touted as a device that could replace full PCs and Macs for people who only needed to perform light computing tasks. Yet, to set up a new iPad, users had to plug it into a PC or Mac running iTunes and use iTunes to activate the device. This is no longer necessary. With new iPads, iPhones, and iPod Touches, you can simply go through the setup process after turning on your new device without ever having to plug it into iTunes. Just connect to a Wi-Fi or cellular data network and log in with your Apple ID when prompted. You’ll still see an option that allows you to activate the device via iTunes, but this should only be necessary if you don’t have a wireless Internet connection available for your device. Operating System Updates You no longer have to use Apple’s iTunes software to update to a new version of Apple’s iOS operating system, either. Just open the Settings app on your device, select the General category, and tap Software Update. You’ll be able to update right from your device without ever opening iTunes. Purchased iTunes Media Apple allows you to easily access content you’ve purchased from the iTunes Store on any device. You don’t have to connect your device to your computer and sync via iTunes. For example, you can purchase a movie from the iTunes Store. Then, without any syncing, you can open the iTunes Store app on any of your iOS devices, tap the Purchased section, and see stuff you’ve downloaded. You can download the content right from the store to your device. This also works for apps — apps you purchase from the App Store can be accessed in the Purchased section on the App Store on your device later. You don’t have to sync apps from iTunes to your device, although iTunes still allows you to. You can even set up automatic downloads from the iTunes & App Store settings screen. This would allow you to purchase content on one device and have it automatically download to your other devices without any hassle. Music Apple allows you to re-download purchased music from the iTunes Store in the same way. However, there’s a good chance you have your own music you didn’t purchase from iTunes. Maybe you spent time ripping it all from your old CDs and you’ve been syncing it to your devices via iTunes ever since. Apple’s solution for this is named iTunes Match. This feature isn’t free, but it’s not a bad deal at all. For $25 per year, Apple allows you to upload all your music to your iCloud account. You can then access all your music from any iPhone, IPad, or iPod Touch. You can stream all your music — perfect if you have a huge library and little storage on your device — and choose which songs you want to download to your device for offline use. When you add additional music to your computer, iTunes will notice it and upload it using iTunes Match, making it available for streaming and downloading directly from your iOS devices without any syncing. This feature is named iTunes Match because it doesn’t just upload music — if Apple already has a song you upload, it will “match” your song with Apple’s copy. This means you may get higher-quality versions of your songs if you ripped them from CD at a lower bitrate. Podcasts You don’t have to use iTunes to subscribe to podcasts and sync them to your devices. Even if you have a lowly iPod Touch, you can install APple’s Podcasts app from the app store. Use it to subscribe to podcasts and configure them to automatically download directly to your device. You can use other podcast apps for this, too. Backups You can continue backing up your device’s data through iTunes, generating local backups that are stored on your computer. However, new iOS devices are configured to automatically back up their data to iCloud. This happens automatically in the background without you even having to think about it, and you can restore such backups when setting up a device simply by logging in with your Apple ID. Personal Data In the days of PalmPilots, people would use desktop programs like iTunes to sync their email, contacts, and calendar events with their mobile devices. You probably shouldn’t have to sync this data form your computer. Just sign into your email account — for example, a Gmail account — on your device and iOS will automatically pull your email, contacts, and calendar events from your associated account. Photos Rather than connecting your iOS device to your computer and syncing photos from it, you can use an app that automatically uploads your photos to a web service. Dropbox, Google+, and even Flickr all have this feature in their apps. You’ll be able to access your photos from any computer and have a backup copy without any syncing required. You may still need to use iTunes if you want to sync local music without paying for iTunes Match or copy local video files to your device. Copying large local files over is the only real scenario where you’d need iTunes. If you don’t need to copy such files over, you can go ahead and uninstall iTunes from your Windows PC if you like. You shouldn’t need it.     

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• Developing Mobile Applications: Web, Native, or Hybrid?

  - by Michelle Kimihira

  Authors: Joe Huang, Senior Principal Product Manager, Oracle Mobile Application Development Framework  and Carlos Chang, Senior Principal Product Director The proliferation of mobile devices and platforms represents a game-changing technology shift on a number of levels. Companies must decide not only the best strategic use of mobile platforms, but also how to most efficiently implement them. Inevitably, this conversation devolves to the developers, who face the task of developing and supporting mobile applications—not a simple task in light of the number of devices and platforms. Essentially, developers can choose from the following three different application approaches, each with its own set of pros and cons. Native Applications: This refers to apps built for and installed on a specific platform, such as iOS or Android, using a platform-specific software development kit (SDK).  For example, apps for Apple’s iPhone and iPad are designed to run specifically on iOS and are written in Xcode/Objective-C. Android has its own variation of Java, Windows uses C#, and so on.  Native apps written for one platform cannot be deployed on another. Native apps offer fast performance and access to native-device services but require additional resources to develop and maintain each platform, which can be expensive and time consuming. Mobile Web Applications: Unlike native apps, mobile web apps are not installed on the device; rather, they are accessed via a Web browser.  These are server-side applications that render HTML, typically adjusting the design depending on the type of device making the request.  There are no program coding constraints for writing server-side apps—they can be written in Java, C, PHP, etc., it doesn’t matter.  Instead, the server detects what type of mobile browser is pinging the server and adjusts accordingly. For example, it can deliver fully JavaScript and CSS-enabled content to smartphone browsers, while downgrading gracefully to basic HTML for feature phone browsers. Mobile apps work across platforms, but are limited to what you can do through a browser and require Internet connectivity. For certain types of applications, these constraints may not be an issue. Oracle supports mobile web applications via ADF Faces (for tablets) and ADF Mobile browser (Trinidad) for smartphone and feature phones. Hybrid Applications: As the name implies, hybrid apps combine technologies from native and mobile Web apps to gain the benefits each. For example, these apps are installed on a device, like their pure native app counterparts, while the user interface (UI) is based on HTML5.  This UI runs locally within the native container, which usually leverages the device’s browser engine.  The advantage of using HTML5 is a consistent, cross-platform UI that works well on most devices.  Combining this with the native container, which is installed on-device, provides mobile users with access to local device services, such as camera, GPS, and local device storage.  Native apps may offer greater flexibility in integrating with device native services.  However, since hybrid applications already provide device integrations that typical enterprise applications need, this is typically less of an issue.  The new Oracle ADF Mobile release is an HTML5 and Java hybrid framework that targets mobile app development to iOS and Android from one code base. So, Which is the Best Approach? The short answer is – the best choice depends on the type of application you are developing.  For instance, animation-intensive apps such as games would favor native apps, while hybrid applications may be better suited for enterprise mobile apps because they provide multi-platform support. Just for starters, the following issues must be considered when choosing a development path. Application Complexity: How complex is the application? A quick app that accesses a database or Web service for some data to display?  You can keep it simple, and a mobile Web app may suffice. However, for a mobile/field worker type of applications that supports mission critical functionality, hybrid or native applications are typically needed. Richness of User Interactivity: What type of user experience is required for the application?  Mobile browser-based app that’s optimized for mobile UI may suffice for quick lookup or productivity type of applications.  However, hybrid/native application would typically be required to deliver highly interactive user experiences needed for field-worker type of applications.  For example, interactive BI charts/graphs, maps, voice/email integration, etc.  In the most extreme case like gaming applications, native applications may be necessary to deliver the highly animated and graphically intensive user experience. Performance: What type of performance is required by the application functionality?  For instance, for real-time look up of data over the network, mobile app performance depends on network latency and server infrastructure capabilities.  If consistent performance is required, data would typically need to be cached, which is supported on hybrid or native applications only. Connectivity and Availability: What sort of connectivity will your application require? Does the app require Web access all the time in order to always retrieve the latest data from the server? Or do the requirements dictate offline support? While native and hybrid apps can be built to operate offline, Web mobile apps require Web connectivity. Multi-platform Requirements: The terms “consumerization of IT” and BYOD (bring your own device) effectively mean that the line between the consumer and the enterprise devices have become blurred. Employees are bringing their personal mobile devices to work and are often expecting that they work in the corporate network and access back-office applications.  Even if companies restrict access to the big dogs: (iPad, iPhone, Android phones and tablets, possibly Windows Phone and tablets), trying to support each platform natively will require increasing resources and domain expertise with each new language/platform. And let’s not forget the maintenance costs, involved in upgrading new versions of each platform.   Where multi-platform support is needed, Web mobile or hybrid apps probably have the advantage. Going native, and trying to support multiple operating systems may be cost prohibitive with existing resources and developer skills. Device-Services Access:  If your app needs to access local device services, such as the camera, contacts app, accelerometer, etc., then your choices are limited to native or hybrid applications.   Fragmentation: Apple controls Apple iOS and the only concern is what version iOS is running on any given device.   Not so Android, which is open source. There are many, many versions and variants of Android running on different devices, which can be a nightmare for app developers trying to support different devices running different flavors of Android.  (Is it an Amazon Kindle Fire? a Samsung Galaxy?  A Barnes & Noble Nook?) This is a nightmare scenario for native apps—on the other hand, a mobile Web or hybrid app, when properly designed, can shield you from these complexities because they are based on common frameworks.  Resources: How many developers can you dedicate to building and supporting mobile application development?  What are their existing skills sets?  If you’re considering native application development due to the complexity of the application under development, factor the costs of becoming proficient on a each platform’s OS and programming language. Add another platform, and that’s another language, another SDK. On the other side of the equation, Web mobile or hybrid applications are simpler to make, and readily support more platforms, but there may be performance trade-offs. Conclusion This only scratches the surface. However, I hope to have suggested some food for thought in choosing your mobile development strategy.  Do your due diligence, search the Web, read up on mobile, talk to peers, attend events. The development team at Oracle is working hard on mobile technologies to help customers extend enterprise applications to mobile faster and effectively.  To learn more on what Oracle has to offer, check out the Oracle ADF Mobile (hybrid) and ADF Faces/ADF Mobile browser (Web Mobile) solutions from Oracle.   Additional Information Blog: ADF Blog Product Information on OTN: ADF Mobile Product Information on Oracle.com: Oracle Fusion Middleware Follow us on Twitter and Facebook Subscribe to our regular Fusion Middleware Newsletter

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• The Faces in the Crowdsourcing

  - by Applications User Experience

  By Jeff Sauro, Principal Usability Engineer, Oracle Imagine having access to a global workforce of hundreds of thousands of people who can perform tasks or provide feedback on a design quickly and almost immediately. Distributing simple tasks not easily done by computers to the masses is called "crowdsourcing" and until recently was an interesting concept, but due to practical constraints wasn't used often. Enter Amazon.com. For five years, Amazon has hosted a service called Mechanical Turk, which provides an easy interface to the crowds. The service has almost half a million registered, global users performing a quarter of a million human intelligence tasks (HITs). HITs are submitted by individuals and companies in the U.S. and pay from $.01 for simple tasks (such as determining if a picture is offensive) to several dollars (for tasks like transcribing audio). What do we know about the people who toil away in this digital crowd? Can we rely on the work done in this anonymous marketplace? A rendering of the actual Mechanical Turk (from Wikipedia) Knowing who is behind Amazon's Mechanical Turk is fitting, considering the history of the actual Mechanical Turk. In the late 1800's, a mechanical chess-playing machine awed crowds as it beat master chess players in what was thought to be a mechanical miracle. It turned out that the creator, Wolfgang von Kempelen, had a small person (also a chess master) hiding inside the machine operating the arms to provide the illusion of automation. The field of human computer interaction (HCI) is quite familiar with gathering user input and incorporating it into all stages of the design process. It makes sense then that Mechanical Turk was a popular discussion topic at the recent Computer Human Interaction usability conference sponsored by the Association for Computing Machinery in Atlanta. It is already being used as a source for input on Web sites (for example, Feedbackarmy.com) and behavioral research studies. Two papers shed some light on the faces in this crowd. One paper tells us about the shifting demographics from mostly stay-at-home moms to young men in India. The second paper discusses the reliability and quality of work from the workers. Just who exactly would spend time doing tasks for pennies? In "Who are the crowdworkers?" University of California researchers Ross, Silberman, Zaldivar and Tomlinson conducted a survey of Mechanical Turk worker demographics and compared it to a similar survey done two years before. The initial survey reported workers consisting largely of young, well-educated women living in the U.S. with annual household incomes above $40,000. The more recent survey reveals a shift in demographics largely driven by an influx of workers from India. Indian workers went from 5% to over 30% of the crowd, and this block is largely male (two-thirds) with a higher average education than U.S. workers, and 64% report an annual income of less than $10,000 (keeping in mind $1 has a lot more purchasing power in India). This shifting demographic certainly has implications as language and culture can play critical roles in the outcome of HITs. Of course, the demographic data came from paying Turkers $.10 to fill out a survey, so there is some question about both a self-selection bias (characteristics which cause Turks to take this survey may be unrepresentative of the larger population), not to mention whether we can really trust the data we get from the crowd. Crowds can perform tasks or provide feedback on a design quickly and almost immediately for usability testing. (Photo attributed to victoriapeckham Flikr While having immediate access to a global workforce is nice, one major problem with Mechanical Turk is the incentive structure. Individuals and companies that deploy HITs want quality responses for a low price. Workers, on the other hand, want to complete the task and get paid as quickly as possible, so that they can get on to the next task. Since many HITs on Mechanical Turk are surveys, how valid and reliable are these results? How do we know whether workers are just rushing through the multiple-choice responses haphazardly answering? In "Are your participants gaming the system?" researchers at Carnegie Mellon (Downs, Holbrook, Sheng and Cranor) set up an experiment to find out what percentage of their workers were just in it for the money. The authors set up a 30-minute HIT (one of the more lengthy ones for Mechanical Turk) and offered a very high $4 to those who qualified and $.20 to those who did not. As part of the HIT, workers were asked to read an email and respond to two questions that determined whether workers were likely rushing through the HIT and not answering conscientiously. One question was simple and took little effort, while the second question required a bit more work to find the answer. Workers were led to believe other factors than these two questions were the qualifying aspect of the HIT. Of the 2000 participants, roughly 1200 (or 61%) answered both questions correctly. Eighty-eight percent answered the easy question correctly, and 64% answered the difficult question correctly. In other words, about 12% of the crowd were gaming the system, not paying enough attention to the question or making careless errors. Up to about 40% won't put in more than a modest effort to get paid for a HIT. Young men and those that considered themselves in the financial industry tended to be the most likely to try to game the system. There wasn't a breakdown by country, but given the demographic information from the first article, we could infer that many of these young men come from India, which makes language and other cultural differences a factor. These articles raise questions about the role of crowdsourcing as a means for getting quick user input at low cost. While compensating users for their time is nothing new, the incentive structure and anonymity of Mechanical Turk raises some interesting questions. How complex of a task can we ask of the crowd, and how much should these workers be paid? Can we rely on the information we get from these professional users, and if so, how can we best incorporate it into designing more usable products? Traditional usability testing will still play a central role in enterprise software. Crowdsourcing doesn't replace testing; instead, it makes certain parts of gathering user feedback easier. One can turn to the crowd for simple tasks that don't require specialized skills and get a lot of data fast. As more studies are conducted on Mechanical Turk, I suspect we will see crowdsourcing playing an increasing role in human computer interaction and enterprise computing. References: Downs, J. S., Holbrook, M. B., Sheng, S., and Cranor, L. F. 2010. Are your participants gaming the system?: screening mechanical turk workers. In Proceedings of the 28th international Conference on Human Factors in Computing Systems (Atlanta, Georgia, USA, April 10 - 15, 2010). CHI '10. ACM, New York, NY, 2399-2402. Link: http://doi.acm.org/10.1145/1753326.1753688 Ross, J., Irani, L., Silberman, M. S., Zaldivar, A., and Tomlinson, B. 2010. Who are the crowdworkers?: shifting demographics in mechanical turk. In Proceedings of the 28th of the international Conference Extended Abstracts on Human Factors in Computing Systems (Atlanta, Georgia, USA, April 10 - 15, 2010). CHI EA '10. ACM, New York, NY, 2863-2872. Link: http://doi.acm.org/10.1145/1753846.1753873

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• Thou shalt not put code on a piedestal - Code is a tool, no more, no less

  - by Ralf Westphal

  “Write great code and everything else becomes easier” is what Paul Pagel believes in. That´s his version of an adage by Brian Marick he cites: “treat code as an end, not just a means.” And he concludes: “My post-Agile world is software craftsmanship.” I wonder, if that´s really the way to go. Will “simply” writing great code lead the software industry into the light? He´s alluding to the philosopher Kant who proposed, a human beings should never be treated as a means, but always as an end. But should we transfer this ethical statement into the world of software? I doubt it.   Reason #1: Human beings are categorially different from code. They are autonomous entities who need to find a way of living happily together. To Kant it seemed this goal could only be reached if nobody (ab)used a human being for his/her purposes. Because using a human being, i.e. treating it as a means, would contradict the fundamental autonomy and freedom of human beings. People should hold up a symmetric view of their relationships: Since nobody wants to be (ab)used, nobody should (ab)use anybody else. If you want to be treated decently, with respect, in accordance with your own free will - which means as an end - then do the same to other people. Code is dead, it´s a product, it´s a tool for people to reach their goals. No company spends any money on code other than to save money or earn money in the long run. Code is not a puppy. Enterprises do not commission software development to just feel good in its company. Code is not a buddy. Code is a slave, if you will. A mechanical slave, a non-tangible robot. Code is a tool, is a tool. And if we start to treat it differently, if we elevate its status unduely… I guess that will contort our relationship in a contraproductive way. Please get me right: Just because something is “just a tool”, “just a product” does not mean we should not be careful while designing, building, using it. Right to the contrary. We should be very careful when writing code – but not for the code´s sake! We should be careful because we respect our customers who are fellow human beings who should be treated as an end. If we are careless, neglectful, ignorant when producing code on their behalf, then we´re using them. Being sloppy means you´re caring more for yourself that for your customer. You´re then treating the customer as a means to fulfill some of your own needs. That´s plain unethical behavior.   Reason #2: The focus should always be on your purpose, not on any tool. But if code is treated as an end, then the focus is on the code. That might sound right, because where else should be your focus as a software developer? But, well, I´d say, your focus should be on delivering value to your customer. Because in the end your customer does not care if you write a single line of code. She just wants her problem to be solved. Solving problems is the purpose of any contractor. Code must be treated just as a means, a tool we know how to handle very well. But if we´re really trying to be craftsmen then we should be conscious about exactly that and act ethically. That means we must never be so focused on our tool as to be unable to suggest better solutions to the problems of our customers than code.   I´m all with Paul when he urges us to “Write great code”. Sure, if you need to write code, then by all means do so. Write the best code you can think of – and then try to improve it. Paul has all the best intentions when he signs Brians “treat code as an end” - but as we all know: “The road to hell is paved with best intentions” ;-) Yes, I can imagine a “hell of code focus”. In fact, I don´t need to imagine it, I´m seeing it quite often. Because code hell is whereever two developers stand together and are so immersed in talking about all sorts of coding tricks, design patterns, code smells, technologies, platforms, tools that they lose sight of the big picture. Talking about TDD or SOLID or refactoring is a sign of consciousness – relative to the “cowboy coders” view of the world. But from yet another point of view TDD, SOLID, and refactoring are just cures for ailments within a system. And I fear, if “Writing great code” is the only focus or the main focus of software development, then we as an industry lose the ability to see that. Focus draws a line around something, it defines a horizon for perceptions and thinking. So if we focus on code our horizon ends where “the land of code” ends. I don´t think that should be our professional attitude.   So what about Software Craftsmanship as the next big thing after Agility? I think Software Craftsmanship has an important message for all software developers and beyond. But to make it the successor of the Agility movement seems to miss a point. Agility never claimed to solve all software development problems, I´d say. So to blame it for having missed out on certain aspects of it is wrong. If I had to summarize Agility in one word I´d say “Value”. Agility put value for the customer back in software development. Focus on delivering value early and often – that´s Agility´s mantra. All else follows from that. And I ask you: Is that obsolete? Is delivering value not hip anymore? No, sure not. That´s our very purpose as software developers. So how can Agility become obsolete and need to be replaced? We need to do away with this “either/or”-thinking. It´s either Agility or Lean or Software Craftsmanship or whatnot. Instead we should start integrating concepts and movements. Think “both/and”. Think Agility plus Software Craftsmanship plus Lean plus whatnot. We don´t neet to tear down anything from a piedestal and replace it with a new idol. Instead we should do away with piedestals and arrange whatever is helpful is a circle. Then we can turn to concepts, movements for whatever they are best. After 10 years of Agility we should be able to identify what it was good at – and keep that. Keep Agility around and add whatever Agility was lacking or never concerned with. Add whatever is at the core of Software Craftsmanship. Add whatever is at the core of Lean etc. But don´t call out the age of Post-Agility. Because it better never will end. Because once we start to lose Agility´s core we´re losing focus of the customer.

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• How to set Grub to automatically load Xen kernel

  - by Cerin

  How do you configure Grub to automatically use the Xen kernel under Ubuntu 11.10? No matter what I do, it loads the first menuentry. The only way I can get it to load Xen is to manually select the kernel, which I can't do if I have to reboot the server remotely, or there's a power failure and the machine automatically boots up when power's restored, etc. It's driving me nuts. In my /boot/grub/grub.cfg, the Xen kernel is at index 4 (i.e. it's the 5th menuentry). So I've tried: Setting GRUB_DEFAULT=4, and running sudo update-grub Setting GRUB_DEFAULT=saved and GRUB_SAVEDEFAULT=true, and running sudo update-grub Setting GRUB_DEFAULT="Ubuntu GNU/Linux, with Xen 4.1-amd64 and Linux 3.0.0-16-server", and running sudo update-grub None of these work. It continues to load the first menuentry, which is "Ubuntu, with Linux 3.0.0-16-server". Below is my current /boot/grub/grub.cfg. What am I doing wrong? # # DO NOT EDIT THIS FILE # # It is automatically generated by grub-mkconfig using templates # from /etc/grub.d and settings from /etc/default/grub # ### BEGIN /etc/grub.d/00_header ### if [ -s $prefix/grubenv ]; then set have_grubenv=true load_env fi set default="Ubuntu GNU/Linux, with Xen 4.1-amd64 and Linux 3.0.0-16-server" if [ "${prev_saved_entry}" ]; then set saved_entry="${prev_saved_entry}" save_env saved_entry set prev_saved_entry= save_env prev_saved_entry set boot_once=true fi function savedefault { if [ -z "${boot_once}" ]; then saved_entry="${chosen}" save_env saved_entry fi } function recordfail { set recordfail=1 if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi } function load_video { insmod vbe insmod vga insmod video_bochs insmod video_cirrus } insmod raid insmod mdraid1x insmod part_msdos insmod part_msdos insmod ext2 set root='(mduuid/be73165bc31d6f5cd00d05036c7b964f)' search --no-floppy --fs-uuid --set=root d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac if loadfont /usr/share/grub/unicode.pf2 ; then set gfxmode=auto load_video insmod gfxterm insmod raid insmod mdraid1x insmod part_msdos insmod part_msdos insmod ext2 set root='(mduuid/be73165bc31d6f5cd00d05036c7b964f)' search --no-floppy --fs-uuid --set=root d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac set locale_dir=($root)/boot/grub/locale set lang=en_US insmod gettext fi terminal_output gfxterm if [ "${recordfail}" = 1 ]; then set timeout=-1 else set timeout=2 fi ### END /etc/grub.d/00_header ### ### BEGIN /etc/grub.d/05_debian_theme ### set menu_color_normal=white/black set menu_color_highlight=black/light-gray if background_color 44,0,30; then clear fi ### END /etc/grub.d/05_debian_theme ### ### BEGIN /etc/grub.d/10_linux ### if [ ${recordfail} != 1 ]; then if [ -e ${prefix}/gfxblacklist.txt ]; then if hwmatch ${prefix}/gfxblacklist.txt 3; then if [ ${match} = 0 ]; then set linux_gfx_mode=keep else set linux_gfx_mode=text fi else set linux_gfx_mode=text fi else set linux_gfx_mode=keep fi else set linux_gfx_mode=text fi export linux_gfx_mode if [ "$linux_gfx_mode" != "text" ]; then load_video; fi menuentry 'Ubuntu, with Linux 3.0.0-16-server' --class ubuntu --class gnu-linux --class gnu --class os { recordfail set gfxpayload=$linux_gfx_mode insmod gzio insmod raid insmod mdraid1x insmod part_msdos insmod part_msdos insmod ext2 set root='(mduuid/be73165bc31d6f5cd00d05036c7b964f)' search --no-floppy --fs-uuid --set=root d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac linux /boot/vmlinuz-3.0.0-16-server root=UUID=d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac ro initrd /boot/initrd.img-3.0.0-16-server } menuentry 'Ubuntu, with Linux 3.0.0-16-server (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod gzio insmod raid insmod mdraid1x insmod part_msdos insmod part_msdos insmod ext2 set root='(mduuid/be73165bc31d6f5cd00d05036c7b964f)' search --no-floppy --fs-uuid --set=root d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac echo 'Loading Linux 3.0.0-16-server ...' linux /boot/vmlinuz-3.0.0-16-server root=UUID=d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac ro recovery nomodeset echo 'Loading initial ramdisk ...' initrd /boot/initrd.img-3.0.0-16-server } submenu "Previous Linux versions" { menuentry 'Ubuntu, with Linux 3.0.0-12-server' --class ubuntu --class gnu-linux --class gnu --class os { recordfail set gfxpayload=$linux_gfx_mode insmod gzio insmod raid insmod mdraid1x insmod part_msdos insmod part_msdos insmod ext2 set root='(mduuid/be73165bc31d6f5cd00d05036c7b964f)' search --no-floppy --fs-uuid --set=root d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac linux /boot/vmlinuz-3.0.0-12-server root=UUID=d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac ro initrd /boot/initrd.img-3.0.0-12-server } menuentry 'Ubuntu, with Linux 3.0.0-12-server (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod gzio insmod raid insmod mdraid1x insmod part_msdos insmod part_msdos insmod ext2 set root='(mduuid/be73165bc31d6f5cd00d05036c7b964f)' search --no-floppy --fs-uuid --set=root d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac echo 'Loading Linux 3.0.0-12-server ...' linux /boot/vmlinuz-3.0.0-12-server root=UUID=d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac ro recovery nomodeset echo 'Loading initial ramdisk ...' initrd /boot/initrd.img-3.0.0-12-server } } ### END /etc/grub.d/10_linux ### ### BEGIN /etc/grub.d/20_linux_xen ### submenu "Xen 4.1-amd64" { menuentry 'Ubuntu GNU/Linux, with Xen 4.1-amd64 and Linux 3.0.0-16-server' --class ubuntu --class gnu-linux --class gnu --class os --class xen { insmod raid insmod mdraid1x insmod part_msdos insmod part_msdos insmod ext2 set root='(mduuid/be73165bc31d6f5cd00d05036c7b964f)' search --no-floppy --fs-uuid --set=root d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac echo 'Loading Xen 4.1-amd64 ...' multiboot /boot/xen-4.1-amd64.gz placeholder echo 'Loading Linux 3.0.0-16-server ...' module /boot/vmlinuz-3.0.0-16-server placeholder root=UUID=d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac ro echo 'Loading initial ramdisk ...' module /boot/initrd.img-3.0.0-16-server } menuentry 'Ubuntu GNU/Linux, with Xen 4.1-amd64 and Linux 3.0.0-16-server (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os --class xen { insmod raid insmod mdraid1x insmod part_msdos insmod part_msdos insmod ext2 set root='(mduuid/be73165bc31d6f5cd00d05036c7b964f)' search --no-floppy --fs-uuid --set=root d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac echo 'Loading Xen 4.1-amd64 ...' multiboot /boot/xen-4.1-amd64.gz placeholder echo 'Loading Linux 3.0.0-16-server ...' module /boot/vmlinuz-3.0.0-16-server placeholder root=UUID=d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac ro single echo 'Loading initial ramdisk ...' module /boot/initrd.img-3.0.0-16-server } menuentry 'Ubuntu GNU/Linux, with Xen 4.1-amd64 and Linux 3.0.0-12-server' --class ubuntu --class gnu-linux --class gnu --class os --class xen { insmod raid insmod mdraid1x insmod part_msdos insmod part_msdos insmod ext2 set root='(mduuid/be73165bc31d6f5cd00d05036c7b964f)' search --no-floppy --fs-uuid --set=root d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac echo 'Loading Xen 4.1-amd64 ...' multiboot /boot/xen-4.1-amd64.gz placeholder echo 'Loading Linux 3.0.0-12-server ...' module /boot/vmlinuz-3.0.0-12-server placeholder root=UUID=d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac ro echo 'Loading initial ramdisk ...' module /boot/initrd.img-3.0.0-12-server } menuentry 'Ubuntu GNU/Linux, with Xen 4.1-amd64 and Linux 3.0.0-12-server (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os --class xen { insmod raid insmod mdraid1x insmod part_msdos insmod part_msdos insmod ext2 set root='(mduuid/be73165bc31d6f5cd00d05036c7b964f)' search --no-floppy --fs-uuid --set=root d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac echo 'Loading Xen 4.1-amd64 ...' multiboot /boot/xen-4.1-amd64.gz placeholder echo 'Loading Linux 3.0.0-12-server ...' module /boot/vmlinuz-3.0.0-12-server placeholder root=UUID=d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac ro single echo 'Loading initial ramdisk ...' module /boot/initrd.img-3.0.0-12-server } } ### END /etc/grub.d/20_linux_xen ### ### BEGIN /etc/grub.d/20_memtest86+ ### menuentry "Memory test (memtest86+)" { insmod raid insmod mdraid1x insmod part_msdos insmod part_msdos insmod ext2 set root='(mduuid/be73165bc31d6f5cd00d05036c7b964f)' search --no-floppy --fs-uuid --set=root d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac linux16 /boot/memtest86+.bin } menuentry "Memory test (memtest86+, serial console 115200)" { insmod raid insmod mdraid1x insmod part_msdos insmod part_msdos insmod ext2 set root='(mduuid/be73165bc31d6f5cd00d05036c7b964f)' search --no-floppy --fs-uuid --set=root d72bad3f-9ed7-44b9-b3d1-d7af9f62a8ac linux16 /boot/memtest86+.bin console=ttyS0,115200n8 } ### END /etc/grub.d/20_memtest86+ ### ### BEGIN /etc/grub.d/30_os-prober ### ### END /etc/grub.d/30_os-prober ### ### BEGIN /etc/grub.d/40_custom ### # This file provides an easy way to add custom menu entries. Simply type the # menu entries you want to add after this comment. Be careful not to change # the 'exec tail' line above. ### END /etc/grub.d/40_custom ### ### BEGIN /etc/grub.d/41_custom ### if [ -f $prefix/custom.cfg ]; then source $prefix/custom.cfg; fi ### END /etc/grub.d/41_custom ###

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• Source-control 'wet-work'?

  - by Phil Factor

  When a design or creative work is flawed beyond remedy, it is often best to destroy it and start again. The other day, I lost the code to a long and intricate SQL batch I was working on. I’d thought it was impossible, but it happened. With all the technology around that is designed to prevent this occurring, this sort of accident has become a rare event.  If it weren’t for a deranged laptop, and my distraction, the code wouldn’t have been lost this time.  As always, I sighed, had a soothing cup of tea, and typed it all in again.  The new code I hastily tapped in  was much better: I’d held in my head the essence of how the code should work rather than the details: I now knew for certain  the start point, the end, and how it should be achieved. Instantly the detritus of half-baked thoughts fell away and I was able to write logical code that performed better.  Because I could work so quickly, I was able to hold the details of all the columns and variables in my head, and the dynamics of the flow of data. It was, in fact, easier and quicker to start from scratch rather than tidy up and refactor the existing code with its inevitable fumbling and half-baked ideas. What a shame that technology is now so good that developers rarely experience the cleansing shock of losing one’s code and having to rewrite it from scratch.  If you’ve never accidentally lost  your code, then it is worth doing it deliberately once for the experience. Creative people have, until Technology mistakenly prevented it, torn up their drafts or sketches, threw them in the bin, and started again from scratch.  Leonardo’s obsessive reworking of the Mona Lisa was renowned because it was so unusual:  Most artists have been utterly ruthless in destroying work that didn’t quite make it. Authors are particularly keen on writing afresh, and the results are generally positive. Lawrence of Arabia actually lost the entire 250,000 word manuscript of ‘The Seven Pillars of Wisdom’ by accidentally leaving it on a train at Reading station, before rewriting a much better version.  Now, any writer or artist is seduced by technology into altering or refining their work rather than casting it dramatically in the bin or setting a light to it on a bonfire, and rewriting it from the blank page.  It is easy to pick away at a flawed work, but the real creative process is far more brutal. Once, many years ago whilst running a software house that supplied commercial software to local businesses, I’d been supervising an accounting system for a farming cooperative. No packaged system met their needs, and it was all hand-cut code.  For us, it represented a breakthrough as it was for a government organisation, and success would guarantee more contracts. As you’ve probably guessed, the code got mangled in a disk crash just a week before the deadline for delivery, and the many backups all proved to be entirely corrupted by a faulty tape drive.  There were some fragments left on individual machines, but they were all of different versions.  The developers were in despair.  Strangely, I managed to re-write the bulk of a three-month project in a manic and caffeine-soaked weekend.  Sure, that elegant universally-applicable input-form routine was‘nt quite so elegant, but it didn’t really need to be as we knew what forms it needed to support.  Yes, the code lacked architectural elegance and reusability. By dawn on Monday, the application passed its integration tests. The developers rose to the occasion after I’d collapsed, and tidied up what I’d done, though they were reproachful that some of the style and elegance had gone out of the application. By the delivery date, we were able to install it. It was a smaller, faster application than the beta they’d seen and the user-interface had a new, rather Spartan, appearance that we swore was done to conform to the latest in user-interface guidelines. (we switched to Helvetica font to look more ‘Bauhaus’ ). The client was so delighted that he forgave the new bugs that had crept in. I still have the disk that crashed, up in the attic. In IT, we have had mixed experiences from complete re-writes. Lotus 123 never really recovered from a complete rewrite from assembler into C, Borland made the mistake with Arago and Quattro Pro  and Netscape’s complete rewrite of their Navigator 4 browser was a white-knuckle ride. In all cases, the decision to rewrite was a result of extreme circumstances where no other course of action seemed possible.   The rewrite didn’t come out of the blue. I prefer to remember the rewrite of Minix by young Linus Torvalds, or the rewrite of Bitkeeper by a slightly older Linus.  The rewrite of CP/M didn’t do too badly either, did it? Come to think of it, the guy who decided to rewrite the windowing system of the Xerox Star never regretted the decision. I’ll agree that one should often resist calls for a rewrite. One of the worst habits of the more inexperienced programmer is to denigrate whatever code he or she inherits, and then call loudly for a complete rewrite. They are buoyed up by the mistaken belief that they can do better. This, however, is a different psychological phenomenon, more related to the idea of some motorcyclists that they are operating on infinite lives, or the occasional squaddies that if they charge the machine-guns determinedly enough all will be well. Grim experience brings out the humility in any experienced programmer.  I’m referring to quite different circumstances here. Where a team knows the requirements perfectly, are of one mind on methodology and coding standards, and they already have a solution, then what is wrong with considering  a complete rewrite? Rewrites are so painful in the early stages, until that point where one realises the payoff, that even I quail at the thought. One needs a natural disaster to push one over the edge. The trouble is that source-control systems, and disaster recovery systems, are just too good nowadays.   If I were to lose this draft of this very blog post, I know I’d rewrite it much better. However, if you read this, you’ll know I didn’t have the nerve to delete it and start again.  There was a time that one prayed that unreliable hardware would deliver you from an unmaintainable mess of a codebase, but now technology has made us almost entirely immune to such a merciful act of God. An old friend of mine with long experience in the software industry has long had the idea of the ‘source-control wet-work’,  where one hires a malicious hacker in some wild eastern country to hack into one’s own  source control system to destroy all trace of the source to an application. Alas, backup systems are just too good to make this any more than a pipedream. Somehow, it would be difficult to promote the idea. As an alternative, could one construct a source control system that, on doing all the code-quality metrics, would systematically destroy all trace of source code that failed the quality test? Alas, I can’t see many managers buying into the idea. In reading the full story of the near-loss of Toy Story 2, it set me thinking. It turned out that the lucky restoration of the code wasn’t the happy ending one first imagined it to be, because they eventually came to the conclusion that the plot was fundamentally flawed and it all had to be rewritten anyway.  Was this an early  case of the ‘source-control wet-job’?’ It is very hard nowadays to do a rapid U-turn in a development project because we are far too prone to cling to our existing source-code.

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• How I Work: Staying Productive Whilst Traveling

  - by BuckWoody

  I travel a lot. Not like some folks that are gone every week, mind you, although in the last month I’ve been to: Cambridge, UK; Anchorage, AK; San Jose, CA; Copenhagen, DK, Boston, MA; and I’m currently en-route to Anaheim, CA.  While this many places in a month is a bit unusual for me, I would say I travel frequently. I’ve travelled most of my 28+ years in IT, and at one time was a consultant traveling weekly.   With that much time away from my primary work location, I have to find ways to stay productive. Some might say “just rest – take a nap!” – but I’m not able to do that. For one thing, I’m a very light sleeper and I’ve never slept on a plane - even a 30+ hour trip to New Zealand in Business Class - so that just isn’t option. I also am not always in the plane, of course. There’s the hotel, the taxi/bus/train, the airport and then all that over again when I arrive. Since my regular jobs have many demands, I have to get work done.   Note: No, I’m not always focused on work. I need downtime just like everyone else. Sometimes I just think, watch a movie or listen to tunes – and I give myself permission to do that anytime – sometimes the whole trip. I have too fewheartbeats left in life to only focus on work – it’s just not that important, and neither am I. Some of these tasks are letters to friends and family, or other personal things. What I’m talking about here is a plan, not some task list I have to follow. When I get to the location I’m traveling to, I always build in as much time as I can to ensure I enjoy those sights and the people I’m with. I would find traveling to be a waste if not for that.   The Unrealistic Expectation As I would evaluate the trip I was taking – say a 6-8 hour flight – I would expect to get 10-12 hours of work done. After all, there’s the time at the airport, the taxi and so on, and then of course the time in the air with all of the room, power, internet and everything else I needed to get my work done. I would pile up tasks at home, pack my bags, and head happily to the magical land of the TSA.   Right. On return from the trip, I had accomplished little, had more e-mails and other work that had piled up, and I was tired, hungry, and unorganized. This had to change. So, I decided to do three things: Segment my work Set realistic expectations Plan accordingly  Segmenting By Available Resources The first task was to decide what kind of work I could do in each location – if any. I found that I was dependent on a few things to get work done, such as power, the Internet, and a place to sit down. Before I fly, I take some time at home to get all of the work I’d like to accomplish while away segmented into these areas, and print that out on paper, which goes in my suit-coat pocket along with a mechanical pencil. I print my tickets, and I’m all set for the adventure ahead. Then I simply do each kind of work whenever I’m in that situation. No power There are certain times when I don’t have power available. But not only that, I might not even be able to use most of my electronics. So I now schedule as many phone calls as I can for the taxi/bus/train ride and the airports as I can. I have a paper notebook (Moleskine, of course) and a pencil and I print out any notes or numbers I need prior to the trip. Once I’m airborne or at the airport, I work on my laptop. I check and respond to e-mails, create slides, write code, do architecture, whatever I can.  If I can’t use any electronics, or once the power runs out, I schedule time for reading. I can read at the airport or anywhere, actually, even in-flight or any other transport. I “read with a pencil”, meaning I take a lot of notes, which I liketo put in OneNote, but since in most cases I don’t have power, I use the Moleskine to do that. Speaking of which, sometimes as I’m thinking I come up with new topics, ideas, blog posts, or things to teach in my classes. Once again I take out the notebook and write it down. All of these notes get a check-mark when I get back to the office and transfer the writing to OneNote. I’ve tried those “smart pens” and so on to automate this, but it just never works out. Pencil and paper are just fine. As I mentioned, sometime I just need to think. I’ll do nothing, and let my mind wander, thinking of nothing in particular, or some math problem or science question I’m interested in. My only issue with this is that I communicate tothink, and I don’t want to drive people crazy by being that guy that won’t shut up, so I think in a different way. Power, but no Internet or Phone If I have power but no Internet or phone, I focus on the laptop and the tablet as before, and I also recharge my other gadgets. Power, Internet, Phone and a Place to Work At first I thought that when I arrived at the hotel or event I could get the same amount of work done that I do at the office. Not so. There’s simply too many distractions, things you need, or other issues that allow this. Of course, Ican work on any device, read, think, write or whatever, but I am simply not as productive as I am in my home office. So I plan for about 25-50% as much work getting done in this environment as I think I could really do. I’ve done some measurements, and this holds out to be true almost every time. The key is that I re-set my expectations (and my co-worker’s expectations as well) that this is the case. I use the Out-Of-Office notices to let people know that I’m just not going to be 100% at this time – it’s hard for everyone, but it’s more honest and realistic, and I’d rather they know that – and that I realize that – than to let them think I’m totally available. Because I’m not – I’m traveling. I don’t tend to put too much detail, because after all I don’t necessarily want to let people know when I’m not home :) but I do think it’s important to let people that depend on my know that I’ll get back with them later. I hope this helps you think through your own methodology of staying productive when you travel. Or perhaps you just go offline, and don’t worry about any of this – good for you! That’s completely valid as well.   (Oh, and yes, I wrote this at 35K feet, on Alaska Airlines on a trip. :)  Practice what you preach, Buck.)

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• Best Practices - which domain types should be used to run applications

  - by jsavit

  This post is one of a series of "best practices" notes for Oracle VM Server for SPARC (formerly named Logical Domains) One question that frequently comes up is "which types of domain should I use to run applications?" There used to be a simple answer in most cases: "only run applications in guest domains", but enhancements to T-series servers, Oracle VM Server for SPARC and the advent of SPARC SuperCluster have made this question more interesting and worth qualifying differently. This article reviews the relevant concepts and provides suggestions on where to deploy applications in a logical domains environment. Review: division of labor and types of domain Oracle VM Server for SPARC offloads many functions from the hypervisor to domains (also called virtual machines). This is a modern alternative to using a "thick" hypervisor that provides all virtualization functions, as in traditional VM designs, This permits a simpler hypervisor design, which enhances reliability, and security. It also reduces single points of failure by assigning responsibilities to multiple system components, which further improves reliability and security. In this architecture, management and I/O functionality are provided within domains. Oracle VM Server for SPARC does this by defining the following types of domain, each with their own roles: Control domain - management control point for the server, used to configure domains and manage resources. It is the first domain to boot on a power-up, is an I/O domain, and is usually a service domain as well. I/O domain - has been assigned physical I/O devices: a PCIe root complex, a PCI device, or a SR-IOV (single-root I/O Virtualization) function. It has native performance and functionality for the devices it owns, unmediated by any virtualization layer. Service domain - provides virtual network and disk devices to guest domains. Guest domain - a domain whose devices are all virtual rather than physical: virtual network and disk devices provided by one or more service domains. In common practice, this is where applications are run. Typical deployment A service domain is generally also an I/O domain: otherwise it wouldn't have access to physical device "backends" to offer to its clients. Similarly, an I/O domain is also typically a service domain in order to leverage the available PCI busses. Control domains must be I/O domains, because they boot up first on the server and require physical I/O. It's typical for the control domain to also be a service domain too so it doesn't "waste" the I/O resources it uses. A simple configuration consists of a control domain, which is also the one I/O and service domain, and some number of guest domains using virtual I/O. In production, customers typically use multiple domains with I/O and service roles to eliminate single points of failure: guest domains have virtual disk and virtual devices provisioned from more than one service domain, so failure of a service domain or I/O path or device doesn't result in an application outage. This is also used for "rolling upgrades" in which service domains are upgraded one at a time while their guests continue to operate without disruption. (It should be noted that resiliency to I/O device failures can also be provided by the single control domain, using multi-path I/O) In this type of deployment, control, I/O, and service domains are used for virtualization infrastructure, while applications run in guest domains. Changing application deployment patterns The above model has been widely and successfully used, but more configuration options are available now. Servers got bigger than the original T2000 class machines with 2 I/O busses, so there is more I/O capacity that can be used for applications. Increased T-series server capacity made it attractive to run more vertical applications, such as databases, with higher resource requirements than the "light" applications originally seen. This made it attractive to run applications in I/O domains so they could get bare-metal native I/O performance. This is leveraged by the SPARC SuperCluster engineered system, announced a year ago at Oracle OpenWorld. In SPARC SuperCluster, I/O domains are used for high performance applications, with native I/O performance for disk and network and optimized access to the Infiniband fabric. Another technical enhancement is the introduction of Direct I/O (DIO) and Single Root I/O Virtualization (SR-IOV), which make it possible to give domains direct connections and native I/O performance for selected I/O devices. A domain with either a DIO or SR-IOV device is an I/O domain. In summary: not all I/O domains own PCI complexes, and there are increasingly more I/O domains that are not service domains. They use their I/O connectivity for performance for their own applications. However, there are some limitations and considerations: at this time, a domain using physical I/O cannot be live-migrated to another server. There is also a need to plan for security and introducing unneeded dependencies: if an I/O domain is also a service domain providing virtual I/O go guests, it has the ability to affect the correct operation of its client guest domains. This is even more relevant for the control domain. where the ldm has to be protected from unauthorized (or even mistaken) use that would affect other domains. As a general rule, running applications in the service domain or the control domain should be avoided. To recap: Guest domains with virtual I/O still provide the greatest operational flexibility, including features like live migration. I/O domains can be used for applications with high performance requirements. This is used to great effect in SPARC SuperCluster and in general T4 deployments. Direct I/O (DIO) and Single Root I/O Virtualization (SR-IOV) make this more attractive by giving direct I/O access to more domains. Service domains should in general not be used for applications, because compromised security in the domain, or an outage, can affect other domains that depend on it. This concern can be mitigated by providing guests' their virtual I/O from more than one service domain, so an interruption of service in the service domain does not cause an application outage. The control domain should in general not be used to run applications, for the same reason. SPARC SuperCluster use the control domain for applications, but it is an exception: it's not a general purpose environment; it's an engineered system with specifically configured applications and optimization for optimal performance. These are recommended "best practices" based on conversations with a number of Oracle architects. Keep in mind that "one size does not fit all", so you should evaluate these practices in the context of your own requirements. Summary Higher capacity T-series servers have made it more attractive to use them for applications with high resource requirements. New deployment models permit native I/O performance for demanding applications by running them in I/O domains with direct access to their devices. This is leveraged in SPARC SuperCluster, and can be leveraged in T-series servers to provision high-performance applications running in domains. Carefully planned, this can be used to provide higher performance for critical applications.

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• A Bite With No Teeth&ndash;Demystifying Non-Compete Clauses

  - by D'Arcy Lussier

  *DISCLAIMER: I am not a lawyer and this post in no way should be considered legal advice. I’m also in Canada, so references made are to Canadian court cases. I received a signed letter the other day, a reminder from my previous employer about some clauses associated with my employment and entry into an employee stock purchase program. So since this is in effect for the next 12 months, I guess I’m not starting that new job tomorrow. I’m kidding of course. How outrageous, how presumptuous, pompous, and arrogant that a company – any company – would actually place these conditions upon an employee. And yet, this is not uncommon. Especially in the IT industry, we see time and again similar wording in our employment agreements. But…are these legal? Is there any teeth behind the threat of the bite? Luckily, the answer seems to be ‘No’. I want to highlight two cases that support this. The first is Lyons v. Multari. In a nutshell, Dentist hires younger Dentist to be an associate. In their short, handwritten agreement, a non-compete clause was written stating “Protective Covenant. 3 yrs. – 5mi” (meaning you can’t set up shop within 5 miles for 3 years). Well, the young dentist left and did start an oral surgery office within 5 miles and within 3 years. Off to court they go! The initial judge sided with the older dentist, but on appeal it was overturned. Feel free to read the transcript of the decision here, but let me highlight one portion from section [19]: The general rule in most common law jurisdictions is that non-competition clauses in employment contracts are void. The sections following [19] explain further, and discuss Elsley v. J.G. Collins Insurance Agency Ltd. and its impact on Canadian law in this regard. The second case is Winnipeg Livestock Sales Ltd. v. Plewman. Desmond Plewman is an auctioneer, and worked at Winnipeg Livestock Sales. Part of his employment agreement was that he could not work for a competitor for 18 months if he left the company. Well, he left, and took up an important role in a competing company. The case went to court and as with Lyons v. Multari, the initial judge found in favour of the plaintiffs. Also as in the first case, that was overturned on appeal. Again, read through the transcript of the decision, but consider section [28]: In other words, even though Plewman has a great deal of skill as an auctioneer, Winnipeg Livestock has no proprietary interest in his professional skill and experience, even if they were acquired during his time working for Winnipeg Livestock.  Thus, Winnipeg Livestock has the burden of establishing that it has a legitimate proprietary interest requiring protection.  On this key question there is little evidence before the Court.  The record discloses that part of Plewman’s job was to “mingle with the … crowd” and to telephone customers and prospective customers about future prospects for the sale of livestock.  It may seem reasonable to assume that Winnipeg Livestock has a legitimate proprietary interest in its customer connections; but there is no evidence to indicate that there is any significant degree of “customer loyalty” in the business, as opposed to customers making choices based on other considerations such as cost, availability and the like. So are there any incidents where a non-compete can actually be valid? Yes, and these are considered “exceptional” cases, meaning that the situation meets certain circumstances. Michael Carabash has a great blog series discussing the above mentioned cases as well as the difference between a non-compete and non-solicit agreement. He talks about the exceptional criteria: In summary, the authorities reveal that the following circumstances will generally be relevant in determining whether a case is an “exceptional” one so that a general non-competition clause will be found to be reasonable: - The length of service with the employer. - The amount of personal service to clients. - Whether the employee dealt with clients exclusively, or on a sustained or     recurring basis. - Whether the knowledge about the client which the employee gained was of a   confidential nature, or involved an intimate knowledge of the client’s   particular needs, preferences or idiosyncrasies. - Whether the nature of the employee’s work meant that the employee had   influence over clients in the sense that the clients relied upon the employee’s   advice, or trusted the employee. - If competition by the employee has already occurred, whether there is   evidence that clients have switched their custom to him, especially without   direct solicitation. - The nature of the business with respect to whether personal knowledge of   the clients’ confidential matters is required. - The nature of the business with respect to the strength of customer loyalty,   how clients are “won” and kept, and whether the clientele is a recurring one. - The community involved and whether there were clientele yet to be exploited   by anyone. I close this blog post with a final quote, one from Zvulony & Co’s blog post on this subject. Again, all of this is not official legal advice, but I think we can see what all these sources are pointing towards. To answer my earlier question, there’s no teeth behind the threat of the bite. In light of this list, and the decisions in Lyons and Orlan, it is reasonably certain that in most employment situations a non-competition clause will be ineffective in protecting an employer from a departing employee who wishes to compete in the same business. The Courts have been relatively consistent in their position that if a non-solicitation clause can protect an employer’s interests, then a non-competition clause is probably unreasonable. Employers (or their solicitors) should avoid the inclination to draft restrictive covenants in broad, catch-all language. Or in other words, when drafting a restrictive covenant – take only what you need! D

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• SOA Implementation Challenges

  Why do companies think that if they put up a web service that they are doing Service-Oriented Architecture (SOA)? Unfortunately, the IT and business world love to run on the latest hype or buzz words of which very few even understand the meaning. One of the largest issues companies have today as they consider going down the path of SOA, is the lack of knowledge regarding the architectural style and the over usage of the term SOA. So how do we solve this issue?I am sure most of you are thinking by now that you know what SOA is because you developed a few web services.  Isn’t that SOA, right? No, that is not SOA, but instead Just Another Web Service (JAWS). For us to better understand what SOA is let’s look at a few definitions.Douglas K. Bary defines service-oriented architecture as a collection of services. These services are enabled to communicate with each other in order to pass data or coordinating some activity with other services.If you look at this definition closely you will notice that Bary states that services communicate with each other. Let us compare this statement with my first statement regarding companies that claim to be doing SOA when they have just a collection of web services. In order for these web services to for an SOA application they need to be interdependent on one another forming some sort of architectural hierarchy. Just because a company has a few web services does not mean that they are all interconnected.SearchSOA from TechTarget.com states that SOA defines how two computing entities work collectively to enable one entity to perform a unit of work on behalf of another. Once again, just because a company has a few web services does not guarantee that they are even working together let alone if they are performing work for each other.SearchSOA also points out service interactions should be self-contained and loosely-coupled so that all interactions operate independent of each other.Of all the definitions regarding SOA Thomas Erl’s seems to shed the most light on this concept. He states that “SOA establishes an architectural model that aims to enhance the efficiency, agility, and productivity of an enterprise by positioning services as the primary means through which solution logic is represented in support of the realization of the strategic goals associated with service-oriented computing.” (Erl, 2011) Once again this definition proves that a collection of web services does not mean that a company is doing SOA. However, it does mean that a company has a collection of web services, and that is it.In order for a company to start to go down the path of SOA, they must take  a hard look at their existing business process while abstracting away any technology so that they can define what is they really want to accomplish. Once a company has done this, they can begin to factor out common sub business process like credit card process, user authentication or system notifications in to small components that can be built independent of each other and then reassembled to form new and dynamic services that are loosely coupled and agile in that they can change as a business grows.Another key pitfall of companies doing SOA is the fact that they let vendors drive their architecture. Why do companies do this? Vendors’ do not hold your company’s success as their top priority; in fact they hold their own success as their top priority by selling you as much stuff as you are willing to buy. In my experience companies tend to strive for the maximum amount of benefits with a minimal amount of cost. Does anyone else see any conflicts between this and the driving force behind vendors.Mike Kavis recommends in an article written in CIO.com that companies need to figure out what they need before they talk to a vendor or at least have some idea of what they need. It is important to thoroughly evaluate each vendor and watch them perform a live demo of their system so that you as the company fully understand what kind of product or service the vendor is actually offering. In addition, do research on each vendor that you are considering, check out blog posts, online reviews, and any information you can find on the vendor through various search engines.Finally he recommends companies to verify any recommendations supplied by a vendor. From personal experience this is very important. I can remember when the company I worked for purchased a $200,000 add-on to their phone system that never actually worked as it was intended. In fact, just after my departure from the company started the process of attempting to get their money back from the vendor. This potentially could have been avoided if the company had done the research before selecting this vendor to ensure that their product and vendor would live up to their claims. I know that some SOA vendor offer free training regarding SOA because they know that there are a lot of misconceptions about the topic. Superficially this is a great thing for companies to take part in especially if the company is starting to implement SOA architecture and are still unsure about some topics or are looking for some guidance regarding the topic. However beware that some companies will focus on their product line only regarding the training. As an example, InfoWorld.com claims that companies providing deep seminars disguised as training, focusing more about ESBs and SOA governance technology, and less on how to approach and solve the architectural issues of the attendees.In short, it is important to remember that we as software professionals are responsible for guiding a business’s technology sections should be well informed and fully understand any new concepts that may be considered for implementation. As I have demonstrated already a company that has a few web services does not mean that they are doing SOA.  Additionally, we must not let the new buzz word of the day drive our technology, but instead our technology decisions should be driven from research and proven experience. Finally, it is important to rely on vendors when necessary, however, always take what they say with a grain of salt while cross checking any claims that they may make because we have to live with the aftermath of a system after the vendors are gone.   References: Barry, D. K. (2011). Service-oriented architecture (SOA) definition. Retrieved 12 12, 2011, from Service-Architecture.com: http://www.service-architecture.com/web-services/articles/service-oriented_architecture_soa_definition.html Connell, B. (2003, 9). service-oriented architecture (SOA). Retrieved 12 12, 2011, from SearchSOA: http://searchsoa.techtarget.com/definition/service-oriented-architecture Erl, T. (2011, 12 12). Service-Oriented Architecture. Retrieved 12 12, 2011, from WhatIsSOA: http://www.whatissoa.com/p10.php InfoWorld. (2008, 6 1). Should you get your SOA knowledge from SOA vendors? . Retrieved 12 12, 2011, from InfoWorld.com: http://www.infoworld.com/d/architecture/should-you-get-your-soa-knowledge-soa-vendors-453 Kavis, M. (2008, 6 18). Top 10 Reasons Why People are Making SOA Fail. Retrieved 12 13, 2011, from CIO.com: http://www.cio.com/article/438413/Top_10_Reasons_Why_People_are_Making_SOA_Fail?page=5&taxonomyId=3016  

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• ATI propriatery drivers install latest 12.8, broke my kernel. Stuck on kernel 3.2.0-26

  - by user66987

  I messed up a bit. Hoping some here can help me. I tried to install the newest catalyst 12.8. Sadly, this broke my system. I was stuck in low graphics mode. I finally managed to restore the proprietary drivers, and get into ubuntu again. But now I am stuck on kernel 3.2.0.26. I had installed kernel 3.2.0-30, but the system no longer sees it. I have kernel 3.2.0-29 too, but the system cannot see that as well. In the grub menu. When I use sudo update-grub, they are both listed. Here are the output I get: Searching for GRUB installation directory ... found: /boot/grub Cannot determine root device. Assuming /dev/hda1 This error is probably caused by an invalid /etc/fstab Searching for default file ... found: /boot/grub/default Testing for an existing GRUB menu.lst file ... found: /boot/grub/menu.lst Searching for splash image ... none found, skipping ... Found kernel: /boot/vmlinuz-3.2.0-30-generic Found kernel: /boot/vmlinuz-3.2.0-29-generic Found kernel: /boot/vmlinuz-3.2.0-27-generic Found kernel: /boot/vmlinuz-3.2.0-26-generic Found GRUB 2: /boot/grub/core.img Found kernel: /boot/memtest86+.bin Updating /boot/grub/menu.lst ... done I have searched everywhere to find a solution to my problem, but can't find any solutions. If you need any log outputs to figure out the problem, please let me know which ones. Update: here is the output for grub.cfg # # DO NOT EDIT THIS FILE # # It is automatically generated by grub-mkconfig using templates # from /etc/grub.d and settings from /etc/default/grub # ### BEGIN /etc/grub.d/00_header ### if [ -s $prefix/grubenv ]; then set have_grubenv=true load_env fi set default="0" if [ "${prev_saved_entry}" ]; then set saved_entry="${prev_saved_entry}" save_env saved_entry set prev_saved_entry= save_env prev_saved_entry set boot_once=true fi function savedefault { if [ -z "${boot_once}" ]; then saved_entry="${chosen}" save_env saved_entry fi } function recordfail { set recordfail=1 if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi } function load_video { insmod vbe insmod vga insmod video_bochs insmod video_cirrus } insmod part_msdos insmod ext2 set root='(hd2,msdos1)' search --no-floppy --fs-uuid --set=root 270c7c58-06d8-4e6b-b9bb-8d92f46adc0b if loadfont /usr/share/grub/unicode.pf2 ; then set gfxmode=auto load_video insmod gfxterm insmod part_msdos insmod ext2 set root='(hd2,msdos1)' search --no-floppy --fs-uuid --set=root 270c7c58-06d8-4e6b-b9bb-8d92f46adc0b set locale_dir=($root)/boot/grub/locale set lang=nb_NO insmod gettext fi terminal_output gfxterm if [ "${recordfail}" = 1 ]; then set timeout=-1 else set timeout=10 fi ### END /etc/grub.d/00_header ### ### BEGIN /etc/grub.d/05_debian_theme ### set menu_color_normal=white/black set menu_color_highlight=black/light-gray if background_color 44,0,30; then clear fi ### END /etc/grub.d/05_debian_theme ### ### BEGIN /etc/grub.d/10_linux ### function gfxmode { set gfxpayload="${1}" if [ "${1}" = "keep" ]; then set vt_handoff=vt.handoff=7 else set vt_handoff= fi } if [ "${recordfail}" != 1 ]; then if [ -e ${prefix}/gfxblacklist.txt ]; then if hwmatch ${prefix}/gfxblacklist.txt 3; then if [ ${match} = 0 ]; then set linux_gfx_mode=keep else set linux_gfx_mode=text fi else set linux_gfx_mode=text fi else set linux_gfx_mode=keep fi else set linux_gfx_mode=text fi export linux_gfx_mode if [ "${linux_gfx_mode}" != "text" ]; then load_video; fi menuentry 'Ubuntu, med Linux 3.2.0-26-generic' --class ubuntu --class gnu-linux --class gnu --class os { recordfail gfxmode $linux_gfx_mode insmod gzio insmod part_msdos insmod ext2 set root='(hd2,msdos1)' search --no-floppy --fs-uuid --set=root 270c7c58-06d8-4e6b-b9bb-8d92f46adc0b linux /boot/vmlinuz-3.2.0-26-generic root=UUID=270c7c58-06d8-4e6b-b9bb-8d92f46adc0b ro quiet splash $vt_handoff initrd /boot/initrd.img-3.2.0-26-generic } menuentry 'Ubuntu, med Linux 3.2.0-26-generic (gjenopprettelsesmodus)' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod gzio insmod part_msdos insmod ext2 set root='(hd2,msdos1)' search --no-floppy --fs-uuid --set=root 270c7c58-06d8-4e6b-b9bb-8d92f46adc0b echo 'Laster Linux 3.2.0-26-generic ...' linux /boot/vmlinuz-3.2.0-26-generic root=UUID=270c7c58-06d8-4e6b-b9bb-8d92f46adc0b ro recovery nomodeset echo 'Loading initial ramdisk ...' initrd /boot/initrd.img-3.2.0-26-generic } submenu "Previous Linux versions" { menuentry 'Ubuntu, med Linux 3.2.0-25-generic' --class ubuntu --class gnu-linux --class gnu --class os { recordfail gfxmode $linux_gfx_mode insmod gzio insmod part_msdos insmod ext2 set root='(hd2,msdos1)' search --no-floppy --fs-uuid --set=root 270c7c58-06d8-4e6b-b9bb-8d92f46adc0b linux /boot/vmlinuz-3.2.0-25-generic root=UUID=270c7c58-06d8-4e6b-b9bb-8d92f46adc0b ro quiet splash $vt_handoff initrd /boot/initrd.img-3.2.0-25-generic } menuentry 'Ubuntu, med Linux 3.2.0-25-generic (gjenopprettelsesmodus)' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod gzio insmod part_msdos insmod ext2 set root='(hd2,msdos1)' search --no-floppy --fs-uuid --set=root 270c7c58-06d8-4e6b-b9bb-8d92f46adc0b echo 'Laster Linux 3.2.0-25-generic ...' linux /boot/vmlinuz-3.2.0-25-generic root=UUID=270c7c58-06d8-4e6b-b9bb-8d92f46adc0b ro recovery nomodeset echo 'Loading initial ramdisk ...' initrd /boot/initrd.img-3.2.0-25-generic } menuentry 'Ubuntu, med Linux 3.2.0-24-generic' --class ubuntu --class gnu-linux --class gnu --class os { recordfail gfxmode $linux_gfx_mode insmod gzio insmod part_msdos insmod ext2 set root='(hd2,msdos1)' search --no-floppy --fs-uuid --set=root 270c7c58-06d8-4e6b-b9bb-8d92f46adc0b linux /boot/vmlinuz-3.2.0-24-generic root=UUID=270c7c58-06d8-4e6b-b9bb-8d92f46adc0b ro quiet splash $vt_handoff initrd /boot/initrd.img-3.2.0-24-generic } menuentry 'Ubuntu, med Linux 3.2.0-24-generic (gjenopprettelsesmodus)' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod gzio insmod part_msdos insmod ext2 set root='(hd2,msdos1)' search --no-floppy --fs-uuid --set=root 270c7c58-06d8-4e6b-b9bb-8d92f46adc0b echo 'Laster Linux 3.2.0-24-generic ...' linux /boot/vmlinuz-3.2.0-24-generic root=UUID=270c7c58-06d8-4e6b-b9bb-8d92f46adc0b ro recovery nomodeset echo 'Loading initial ramdisk ...' initrd /boot/initrd.img-3.2.0-24-generic } menuentry 'Ubuntu, med Linux 3.2.0-23-generic' --class ubuntu --class gnu-linux --class gnu --class os { recordfail gfxmode $linux_gfx_mode insmod gzio insmod part_msdos insmod ext2 set root='(hd2,msdos1)' search --no-floppy --fs-uuid --set=root 270c7c58-06d8-4e6b-b9bb-8d92f46adc0b linux /boot/vmlinuz-3.2.0-23-generic root=UUID=270c7c58-06d8-4e6b-b9bb-8d92f46adc0b ro quiet splash $vt_handoff initrd /boot/initrd.img-3.2.0-23-generic } menuentry 'Ubuntu, med Linux 3.2.0-23-generic (gjenopprettelsesmodus)' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod gzio insmod part_msdos insmod ext2 set root='(hd2,msdos1)' search --no-floppy --fs-uuid --set=root 270c7c58-06d8-4e6b-b9bb-8d92f46adc0b echo 'Laster Linux 3.2.0-23-generic ...' linux /boot/vmlinuz-3.2.0-23-generic root=UUID=270c7c58-06d8-4e6b-b9bb-8d92f46adc0b ro recovery nomodeset echo 'Loading initial ramdisk ...' initrd /boot/initrd.img-3.2.0-23-generic } } ### END /etc/grub.d/10_linux ### ### BEGIN /etc/grub.d/20_linux_xen ### ### END /etc/grub.d/20_linux_xen ### ### BEGIN /etc/grub.d/20_memtest86+ ### menuentry "Memory test (memtest86+)" { insmod part_msdos insmod ext2 set root='(hd2,msdos1)' search --no-floppy --fs-uuid --set=root 270c7c58-06d8-4e6b-b9bb-8d92f46adc0b linux16 /boot/memtest86+.bin } menuentry "Memory test (memtest86+, serial console 115200)" { insmod part_msdos insmod ext2 set root='(hd2,msdos1)' search --no-floppy --fs-uuid --set=root 270c7c58-06d8-4e6b-b9bb-8d92f46adc0b linux16 /boot/memtest86+.bin console=ttyS0,115200n8 } ### END /etc/grub.d/20_memtest86+ ### ### BEGIN /etc/grub.d/30_os-prober ### menuentry "Windows 7 (loader) (on /dev/sdb1)" --class windows --class os { insmod part_msdos insmod ntfs set root='(hd1,msdos1)' search --no-floppy --fs-uuid --set=root 448AF3CE8AF3BA8E chainloader +1 } ### END /etc/grub.d/30_os-prober ### ### BEGIN /etc/grub.d/40_custom ### # This file provides an easy way to add custom menu entries. Simply type the # menu entries you want to add after this comment. Be careful not to change # the 'exec tail' line above. ### END /etc/grub.d/40_custom ### ### BEGIN /etc/grub.d/41_custom ### if [ -f $prefix/custom.cfg ]; then source $prefix/custom.cfg; fi ### END /etc/grub.d/41_custom ### How can I set kernel 3.2.0.30 as the default kernel? According to this file, kernel 3.2.0-30 does not exist.

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• C# Bind DataTable to Existing DataGridView Column Definitions

  - by Timothy

  I've been struggling with a NullReferenceException and hope someone here will be able to point me in the right direction. I'm trying to create and populate a DataTable and then show the results in a DataGridView control. The basic code follows, and Execution stops with a NullReferenceException at the point where I invoke the new UpdateResults_Delegate. Oddly enough, I can trace entries.Rows.Count successfully before I return it from QueryEventEntries, so I can at least show 1) entries is not a null reference, and 2) the DataTable contains rows of data. I know I have to be doing something wrong, but I just don't know what. private void UpdateResults(DataTable entries) { dataGridView.DataSource = entries; } private void button_Click(object sender, EventArgs e) { PerformQuery(); } private void PerformQuery() { DateTime start = new DateTime(dateTimePicker1.Value.Year, dateTimePicker1.Value.Month, dateTimePicker1.Value.Day, 0, 0, 0); DateTime stop = new DateTime(dateTimePicker2.Value.Year, dateTimePicker2.Value.Month, dateTimePicker2.Value.Day, 0, 0, 0); DataTable entries = QueryEventEntries(start, stop); UpdateResults(entries); } private DataTable QueryEventEntries(DateTime start, DateTime stop) { DataTable entries = new DataTable(); entries.Columns.AddRange(new DataColumn[] { new DataColumn("event_type", typeof(Int32)), new DataColumn("event_time", typeof(DateTime)), new DataColumn("event_detail", typeof(String))}); using (SqlConnection conn = new SqlConnection(DSN)) { using (SqlDataAdapter adapter = new SqlDataAdapter( "SELECT event_type, event_time, event_detail FROM event_log " + "WHERE event_time >= @start AND event_time <= @stop", conn)) { adapter.SelectCommand.Parameters.AddRange(new Object[] { new SqlParameter("@start", start), new SqlParameter("@stop", stop)}); adapter.Fill(entries); } } return entries; } Update I'd like to summarize and provide some additional information I've learned from the discussion here and debugging efforts since I originally posted this question. I am refactoring old code that retrieved records from a database, collected those records as an array, and then later iterated through the array to populate a DataGridView row by row. Threading was originally implemented to compensate and keep the UI responsive during the unnecessary looping. I have since stripped out Thread/Invoke; everything now occurs on the same execution thread (thank you, Sam). I am attempting to replace the slow, unwieldy approach using a DataTable which I can fill with a DataAdapter, and assign to the DataGridView through it's DataSource property (above code updated). I've iterated through the entries DataTable's rows to verify the table contains the expected data before assigning it as the DataGridView's DataSource. foreach (DataRow row in entries.Rows) { System.Diagnostics.Trace.WriteLine( String.Format("{0} {1} {2}", row[0], row[1], row[2])); } One of the column of the DataGridView is a custom DataGridViewColumn to stylize the event_type value. I apologize I didn't mention this before in the original post but I wasn't aware it was important to my problem. I have converted this column temporarily to a standard DataGridViewTextBoxColumn control and am no longer experiencing the Exception. The fields in the DataTable are appended to the list of fields that have been pre-specified in Design view of the DataGridView. The records' values are being populated in these appended fields. When the run time attempts to render the cell a null value is provided (as the value that should be rendered is done so a couple columns over). In light of this, I am re-titling and re-tagging the question. I would still appreciate it if others who have experienced this can instruct me on how to go about binding the DataTable to the existing column definitions of the DataGridView.

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• Why isn't the Spring AOP XML schema properly loaded when Tomcat loads & reads beans.xml

  - by chrisbunney

  I'm trying to use Spring's Schema Based AOP Support in Eclipse and am getting errors when trying to load the configuration in Tomcat. There are no errors in Eclipse and auto-complete works correctly for the aop namespace, however when I try to load the project into eclipse I get this error: 09:17:59,515 WARN XmlBeanDefinitionReader:47 - Ignored XML validation warning org.xml.sax.SAXParseException: schema_reference.4: Failed to read schema document 'http://www.springframework.org/schema/aop/spring-aop-2.5.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not . Followed by: SEVERE: StandardWrapper.Throwable org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 39 in XML document from /WEB-INF/beans.xml is invalid; nested exception is org.xml.sax.SAXParseException: cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'aop:config'. Caused by: org.xml.sax.SAXParseException: cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'aop:config'. Based on this, it seems the schema is not being read when Tomcat parses the beans.xml file, leading to the <aop:config> element not being recognised. My beans.xml file is as follows: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:jaxws="http://cxf.apache.org/jaxws" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://cxf.apache.org/jaxws http://cxf.apache.org/schemas/jaxws.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd"> <!--import resource="classpath:META-INF/cxf/cxf.xml" /--> <!--import resource="classpath:META-INF/cxf/cxf-extension-soap.xml" /--> <!--import resource="classpath:META-INF/cxf/cxf-servlet.xml" /--> <!-- NOTE: endpointName attribute maps to wsdl:port@name & should be the same as the portName attribute in the @WebService annotation on the IWebServiceImpl class --> <!-- NOTE: serviceName attribute maps to wsdl:service@name & should be the same as the serviceName attribute in the @WebService annotation on the ASDIWebServiceImpl class --> <!-- NOTE: address attribute is the actual URL of the web service (relative to web app location) --> <jaxws:endpoint xmlns:tns="http://iwebservices.ourdomain/" id="iwebservices" implementor="ourdomain.iwebservices.IWebServiceImpl" endpointName="tns:IWebServiceImplPort" serviceName="tns:IWebService" address="/I" wsdlLocation="wsdl/I.wsdl"> <!-- To have CXF auto-generate WSDL on the fly, comment out the above wsdl attribute --> <jaxws:features> <bean class="org.apache.cxf.feature.LoggingFeature" /> </jaxws:features> </jaxws:endpoint> <aop:config> <aop:aspect id="myAspect" ref="aBean"> </aop:aspect> </aop:config> </beans> The <aop:config> element in my beans.xml file is copy-pasted from the Spring website to try and remove any possible source of error Can anyone shed any light on why this error is occurring and what I can do to fix it?

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• "Content is not allowed in prolog" when parsing perfectly valid XML on GAE

  - by Adrian Petrescu

  Hey guys, I've been beating my head against this absolutely infuriating bug for the last 48 hours, so I thought I'd finally throw in the towel and try asking here before I throw my laptop out the window. I'm trying to parse the response XML from a call I made to AWS SimpleDB. The response is coming back on the wire just fine; for example, it may look like: <?xml version="1.0" encoding="utf-8"?> <ListDomainsResponse xmlns="http://sdb.amazonaws.com/doc/2009-04-15/"> <ListDomainsResult> <DomainName>Audio</DomainName> <DomainName>Course</DomainName> <DomainName>DocumentContents</DomainName> <DomainName>LectureSet</DomainName> <DomainName>MetaData</DomainName> <DomainName>Professors</DomainName> <DomainName>Tag</DomainName> </ListDomainsResult> <ResponseMetadata> <RequestId>42330b4a-e134-6aec-e62a-5869ac2b4575</RequestId> <BoxUsage>0.0000071759</BoxUsage> </ResponseMetadata> </ListDomainsResponse> I pass in this XML to a parser with XMLEventReader eventReader = xmlInputFactory.createXMLEventReader(response.getContent()); and call eventReader.nextEvent(); a bunch of times to get the data I want. Here's the bizarre part -- it works great inside the local server. The response comes in, I parse it, everyone's happy. The problem is that when I deploy the code to Google App Engine, the outgoing request still works, and the response XML seems 100% identical and correct to me, but the response fails to parse with the following exception: com.amazonaws.http.HttpClient handleResponse: Unable to unmarshall response (ParseError at [row,col]:[1,1] Message: Content is not allowed in prolog.): <?xml version="1.0" encoding="utf-8"?> <ListDomainsResponse xmlns="http://sdb.amazonaws.com/doc/2009-04-15/"><ListDomainsResult><DomainName>Audio</DomainName><DomainName>Course</DomainName><DomainName>DocumentContents</DomainName><DomainName>LectureSet</DomainName><DomainName>MetaData</DomainName><DomainName>Professors</DomainName><DomainName>Tag</DomainName></ListDomainsResult><ResponseMetadata><RequestId>42330b4a-e134-6aec-e62a-5869ac2b4575</RequestId><BoxUsage>0.0000071759</BoxUsage></ResponseMetadata></ListDomainsResponse> javax.xml.stream.XMLStreamException: ParseError at [row,col]:[1,1] Message: Content is not allowed in prolog. at com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next(Unknown Source) at com.sun.xml.internal.stream.XMLEventReaderImpl.nextEvent(Unknown Source) at com.amazonaws.transform.StaxUnmarshallerContext.nextEvent(StaxUnmarshallerContext.java:153) ... (rest of lines omitted) I have double, triple, quadruple checked this XML for 'invisible characters' or non-UTF8 encoded characters, etc. I looked at it byte-by-byte in an array for byte-order-marks or something of that nature. Nothing; it passes every validation test I could throw at it. Even stranger, it happens if I use a Saxon-based parser as well -- but ONLY on GAE, it always works fine in my local environment. It makes it very hard to trace the code for problems when I can only run the debugger on an environment that works perfectly (I haven't found any good way to remotely debug on GAE). Nevertheless, using the primitive means I have, I've tried a million approaches including: XML with and without the prolog With and without newlines With and without the "encoding=" attribute in the prolog Both newline styles With and without the chunking information present in the HTTP stream And I've tried most of these in multiple combinations where it made sense they would interact -- nothing! I'm at my wit's end. Has anyone seen an issue like this before that can hopefully shed some light on it? Thanks!

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• WPF Binding Error reported when Binding appears to work fine

  - by Noldorin

  I am trying to create a custom TabItem template/style in my WPF 4.0 application (using VS 2010 Pro RTM), but inspite of everything seeming to work correctly, I am noticing a binding error in the trace window. The resource dictionary XAML I use to style the TabItems of a TabControl is given in full here. (Just create a simple TabControl with several items and apply the given ResourceDictionary to test it out.) Specifically, the error is occurring due to the following line (discovered through trial and error testing, since Visual Studio isn't actually reporting it at design tim <TranslateTransform X="{Binding ActualWidth, ElementName=leftSideBorderPath}"/> The full error given in the trace (Ouput window) is the following: System.Windows.Data Error: 2 : Cannot find governing FrameworkElement or FrameworkContentElement for target element. BindingExpression:Path=ActualWidth; DataItem=null; target element is 'TranslateTransform' (HashCode=35345840); target property is 'X' (type 'Double') The error occurs on load and is repeated 5 times then (note that I have 3 tab items in my example). It also occurs consistently and repeatedly whenever for the Window is resized, for example - filling the Output window. Perhaps every time the TabItem layout is updated? And again, though it is not reported, the error very much seems to be due to the fact that I am binding to any element at all, not specifically leftSideBorderPath or the the ActualWidth propertry. For example, changing this line to the following fixes things. <TranslateTransform X="25"/> Unfortunately, hard-coding the value isn't really an option. This issue seems very strange to me in that the binding does appear to be giving the correct results. (Inspecting the X value of the TranslateTransform at runtime clearly shows the correct bound value, and the ClipGeometry when viewed is exactly what it hsould be.) Neither Visual Studio nor WPF seems to be giving me any more information on the cause of the error perhaps (setting PresentationTraceSources.TraceLevel to High doesn't help), yet the fact that things are working despite the error being reported inclines me to think that this is some fringe-case WPF bug. As a side note, the Visual Studio WPF designer and XAML editor are giving me a problem with the following line: <PathGeometry Figures="{Binding Source={StaticResource TabSideFillFigures}}"/> Although WPF (at runtime) is perfectly happy binding Figures to the TabSideFillFigures string, with the Binding enforcing the use of the TypeConverter, the XAML editor and WPF designer are complaining. All the XAML code for the ControlTemplate is underlined and I get the following errors in the Error List: Error 9 '{DependencyProperty.UnsetValue}' is not a valid value for the 'System.Windows.Controls.Control.Template' property on a Setter. C:\Users\Alex\Documents\Visual Studio 2010\Projects\Ircsil\devel\Ircsil\MainWindow.xaml 1 1 Ircsil Error 10 Object reference not set to an instance of an object. C:\Users\Alex\Documents\Visual Studio 2010\Projects\Ircsil\devel\Ircsil\Skins\Default\MainSkin.xaml 58 17 Ircsil Again, to repeat, everything works perfectly well at runtime, which is what makes this particularly odd... Could someone perhaps shed some light on these issues, in particular the first (which seems to be a potential WPF bug), and the latter (which seems to be a Visual Studio bug). Any sort of feedback or suggestions would be much appreciated!

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• What does it mean when ARP shows <incomplete> on eth1

  - by Geoff Dalgas

  We have been using HAProxy along with heartbeat from the Linux-HA project. We are using two linux instances to provide a failover. Each server has with their own public IP and a single IP which is shared between the two using a virtual interface (eth1:1) at IP: 69.59.196.211 The virtual interface (eth1:1) IP 69.59.196.211 is configured as the gateway for the windows servers behind them and we use ip_forwarding to route traffic. We are experiencing an occasional network outage on one of our windows servers behind our linux gateways. HAProxy will detect the server is offline which we can verify by remoting to the failed server and attempting to ping the gateway: Pinging 69.59.196.211 with 32 bytes of data: Reply from 69.59.196.220: Destination host unreachable. Running arp -a on this failed server shows that there is no entry for the gateway address (69.59.196.211): Interface: 69.59.196.220 --- 0xa Internet Address Physical Address Type 69.59.196.161 00-26-88-63-c7-80 dynamic 69.59.196.210 00-15-5d-0a-3e-0e dynamic 69.59.196.212 00-21-5e-4d-45-c9 dynamic 69.59.196.213 00-15-5d-00-b2-0d dynamic 69.59.196.215 00-21-5e-4d-61-1a dynamic 69.59.196.217 00-21-5e-4d-2c-e8 dynamic 69.59.196.219 00-21-5e-4d-38-e5 dynamic 69.59.196.221 00-15-5d-00-b2-0d dynamic 69.59.196.222 00-15-5d-0a-3e-09 dynamic 69.59.196.223 ff-ff-ff-ff-ff-ff static 224.0.0.22 01-00-5e-00-00-16 static 224.0.0.252 01-00-5e-00-00-fc static 225.0.0.1 01-00-5e-00-00-01 static On our linux gateway instances arp -a shows: peak-colo-196-220.peak.org (69.59.196.220) at <incomplete> on eth1 stackoverflow.com (69.59.196.212) at 00:21:5e:4d:45:c9 [ether] on eth1 peak-colo-196-215.peak.org (69.59.196.215) at 00:21:5e:4d:61:1a [ether] on eth1 peak-colo-196-219.peak.org (69.59.196.219) at 00:21:5e:4d:38:e5 [ether] on eth1 peak-colo-196-222.peak.org (69.59.196.222) at 00:15:5d:0a:3e:09 [ether] on eth1 peak-colo-196-209.peak.org (69.59.196.209) at 00:26:88:63:c7:80 [ether] on eth1 peak-colo-196-217.peak.org (69.59.196.217) at 00:21:5e:4d:2c:e8 [ether] on eth1 Why would arp occasionally set the entry for this failed server as <incomplete>? Should we be defining our arp entries statically? I've always left arp alone since it works 99% of the time, but in this one instance it appears to be failing. Are there any additional troubleshooting steps we can take help resolve this issue? THINGS WE HAVE TRIED I added a static arp entry for testing on one of the linux gateways which still didn't help. root@haproxy2:~# arp -a peak-colo-196-215.peak.org (69.59.196.215) at 00:21:5e:4d:61:1a [ether] on eth1 peak-colo-196-221.peak.org (69.59.196.221) at 00:15:5d:00:b2:0d [ether] on eth1 stackoverflow.com (69.59.196.212) at 00:21:5e:4d:45:c9 [ether] on eth1 peak-colo-196-219.peak.org (69.59.196.219) at 00:21:5e:4d:38:e5 [ether] on eth1 peak-colo-196-209.peak.org (69.59.196.209) at 00:26:88:63:c7:80 [ether] on eth1 peak-colo-196-217.peak.org (69.59.196.217) at 00:21:5e:4d:2c:e8 [ether] on eth1 peak-colo-196-220.peak.org (69.59.196.220) at 00:21:5e:4d:30:8d [ether] PERM on eth1 root@haproxy2:~# arp -i eth1 -s 69.59.196.220 00:21:5e:4d:30:8d root@haproxy2:~# ping 69.59.196.220 PING 69.59.196.220 (69.59.196.220) 56(84) bytes of data. --- 69.59.196.220 ping statistics --- 7 packets transmitted, 0 received, 100% packet loss, time 6006ms Rebooting the windows web server solves this issue temporarily with no other changes to the network but our experience shows this issue will come back. Swapping network cards and switches I noticed the link light on the port of the switch for the failed windows server was running at 100Mb instead of 1Gb on the failed interface. I moved the cable to several other open ports and the link indicated 100Mb for each port that I tried. I also swapped the cable with the same result. I tried changing the properties of the network card in windows and the server locked up and required a hard reset after clicking apply. This windows server has two physical network interfaces so I have swapped the cables and network settings on the two interfaces to see if the problem follows the interface. If the public interface goes down again we will know that it is not an issue with the network card. (We also tried another switch we have on hand, no change) Changing network hardware driver versions We've had the same problem with the latest Broadcom driver, as well as the built-in driver that ships in Windows Server 2008 R2. Replacing network cables As a last ditch effort we remembered another change that occurred was the replacement of all of the patch cords between our servers / switch. We had purchased two sets, one green of lengths 1ft - 3ft for the private interfaces and another set of red cables for the public interfaces. We swapped out all of the public interface patch cables with a different brand and ran our servers without issue for a full week ... aaaaaand then the problem recurred. Disable checksum offload, remove TProxy We also tried disabling TCP/IP checksum offload in the driver, no change. We're now pulling out TProxy and moving to a more traditional x-forwarded-for network arrangement without any fancy IP address rewriting. We'll see if that helps.

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• WCF errors in VS 2010/.Net 4 using sample publish/subscribe app from IDesign website

  - by Bill

  I am attempting to compile/run a sample WCF application from Juval Lowy's website (author of Programming WCF Services & founder of IDesign). The application is an example of a publish/subscribe 'traffic-light' application that requires using VS 2010/.Net 4. This is my first attempt at using anything other than VS 2008/Net 3.5. Initially I recieved the following binding error: "Configuration binding extension 'system.serviceModel/bindings/ netOnewayRelayBinding' could not be found." This error appeared to be resolved by amending the .Net 4 machine.config file, to incorporate the following references from the .Net 2 machine.config file. <xml> <bindingElementExtensions> <add name="tcpRelayTransport" type="Microsoft.ServiceBus.Configuration.TcpRelayTransportElement, Microsoft.ServiceBus, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> <add name="httpRelayTransport" type="Microsoft.ServiceBus.Configuration.HttpRelayTransportElement, Microsoft.ServiceBus, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> <add name="httpsRelayTransport" type="Microsoft.ServiceBus.Configuration.HttpsRelayTransportElement, Microsoft.ServiceBus, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> <add name="onewayRelayTransport" type="Microsoft.ServiceBus.Configuration.RelayedOnewayTransportElement, Microsoft.ServiceBus, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> <add name="webMessageEncoding" type="System.ServiceModel.Configuration.WebMessageEncodingElement, System.ServiceModel.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> <add name="context" type="System.ServiceModel.Configuration.ContextBindingElementExtensionElement, System.ServiceModel, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/> <add name="byteStreamMessageEncoding" type="System.ServiceModel.Configuration.ByteStreamMessageEncodingElement, System.ServiceModel.Channels, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> <add name="discoveryClient" type="System.ServiceModel.Discovery.Configuration.DiscoveryClientElement, System.ServiceModel.Discovery, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> </bindingElementExtensions> <bindingExtensions> <add name="webHttpBinding" type="System.ServiceModel.Configuration.WebHttpBindingCollectionElement, System.ServiceModel.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> <add name="basicHttpContextBinding" type="System.ServiceModel.Configuration.BasicHttpContextBindingCollectionElement, System.ServiceModel, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/> <add name="basicHttpRelayBinding" type="Microsoft.ServiceBus.Configuration.BasicHttpRelayBindingCollectionElement, Microsoft.ServiceBus, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> <add name="webHttpRelayBinding" type="Microsoft.ServiceBus.Configuration.WebHttpRelayBindingCollectionElement, Microsoft.ServiceBus, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> <add name="ws2007HttpRelayBinding" type="Microsoft.ServiceBus.Configuration.WS2007HttpRelayBindingCollectionElement, Microsoft.ServiceBus, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> <add name="netTcpRelayBinding" type="Microsoft.ServiceBus.Configuration.NetTcpRelayBindingCollectionElement, Microsoft.ServiceBus, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> <add name="netOnewayRelayBinding" type="Microsoft.ServiceBus.Configuration.NetOnewayRelayBindingCollectionElement, Microsoft.ServiceBus, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> <add name="netEventRelayBinding" type="Microsoft.ServiceBus.Configuration.NetEventRelayBindingCollectionElement, Microsoft.ServiceBus, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> <add name="wsHttpContextBinding" type="System.ServiceModel.Configuration.WSHttpContextBindingCollectionElement, System.ServiceModel, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/> <add name="netTcpContextBinding" type="System.ServiceModel.Configuration.NetTcpContextBindingCollectionElement, System.ServiceModel, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/> </bindingExtensions> Unfortunately running the application results in the following security error: An error occurred creating the configuration section handler for system.serviceModel/client: That assembly does not allow partially trusted callers. (\TrafficLights\TrafficController\bin\Debug\TrafficController.vshost.exe.Config line 4) The sample source code is available for download at the following link: http://www.idesign.net/idesign/DesktopDefault.aspx?tabindex=-1&tabid=19&download=226 I know that Juval's code is not at fault here and that it must be something I'm doing wrong with my VS 2010 configuration. I have not been able to find a solution online. Could someone please steer me in the right direction as to how best to deal with this issue?

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• On REST: WADL or not IDL, is the following approach right ?

  - by redben

  This question is a bit long, please bear with me. In REST, i think we should not need WADL or any IDL. But rather something that would implicitly cover its concept. The way I think about it is when we (humans) surf the Web, when we go to a web site for the first time, we don't know what services it provides. You discover those on the html home page (or a sitemap page in a help section) or maybe just the main menu on the home page. If you make an analogy, the homepage or site map to us humans is what WSDL is to WS-* or what WADL could be to a REST service. Only that its just like any other html content. I think that in REST the following is a good way to do things, respecting the HATEOS paradigm. Have a top level (or default) resource that lists links to your other resources. For a library example, say RestLibrary.com/ it could be something like: <root xmlns:lib="http://librarystandards.com/libraryml"> <resource class="lib:book"> <link type="application/vnd.libraryml+xml" template="mylib.com/book/{isbn}" /> <link type="application/vnd.libraryml+xml" rel="add" href="mylib.com/book" method="POST" /> <link type="application/vnd.libraryml+xml" rel="update" template="mylib.com/book/{isbn}" method="PUT" /> </resource> <resource class="lib:bookList"> <link template="mylib.com/book?keywords={keywords}" type="application/vnd.openlibrary+xml" rel="search" /> </resource> </root> Note that it is assumed that the media type "application/vnd.libraryml+xml" is a defined standard or (may be just proprietary vocabulary) named libraryml. Also, the client should be able to understand this "homepage" resource (elements root, resource and link). This is the part that could be used instead of WADL : an Abstract vocabulary that should be understandable by any client. You could use an existing standard like Atom for example. But the main idea is to have an abstract vocabulary understandable by any client. Why not WADL then ? well wadl is only for service discovery. The idea here is to have an light abstract vocabulary that would serve as a base for hypermedia. A "root" vocabulary. Like in owl we have owl:thing...etc Now if the client knows the "libraryml" standard it can follow the links to the things it understands (after parsing the media type properties and xmlns). If not, it just won't. When i can't understand how to deal with something in REST architecture i tend to see how we Humans do it in the Web. In the Web, we have the Generic language that is HTML that enables site builders to deliver any specific content, regardless of its meaning to the client (the user), Browsers understand HTML but not the "meaning" of its content. It is the user that understands the (domain specific) content. If i go to say QuantumPhysics.org, my browser can render the home page (it is just html after all) and i can read the home page. If i understand quantum then fine i can continue browsing. If i don't i just get out (unless i want to learn the hardway :) ) In the RetsLibrary.com example the client app is just like me+my browser on QuantumPhysics.org. the media type "application/vnd.libraryml+xml" is quantum physics (knowledge). http is http in both examples. Now HTML of QuantumPhysics.org is in RestLibrary.com is XML + that tiny little abstract vocabulary (root resource and link, that you could replace with something like Atom). So does this approach have any value ? don't we need a root tiny hyper-vocabulary so we can succeed with hypermedia and the "initial URI" concept ? edit Yeah why not RDF as the root vocabulary !

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