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  • best way to "introduce" OOP/OOD to team of experienced C++ engineers

    - by DXM
    I am looking for an efficient way, that also doesn't come off as an insult, to introduce OOP concepts to existing team members? My teammates are not new to OO languages. We've been doing C++/C# for a long time so technology itself is familiar. However, I look around and without major infusion of effort (mostly in the form of code reviews), it seems what we are producing is C code that happens to be inside classes. There's almost no use of single responsibility principle, abstractions or attempts to minimize coupling, just to name a few. I've seen classes that don't have a constructor but get memset to 0 every time they are instantiated. But every time I bring up OOP, everyone always nods and makes it seem like they know exactly what I'm talking about. Knowing the concepts is good, but we (some more than others) seem to have very hard time applying them when it comes to delivering actual work. Code reviews have been very helpful but the problem with code reviews is that they only occur after the fact so to some it seems we end up rewriting (it's mostly refactoring, but still takes lots of time) code that was just written. Also code reviews only give feedback to an individual engineer, not the entire team. I am toying with the idea of doing a presentation (or a series) and try to bring up OOP again along with some examples of existing code that could've been written better and could be refactored. I could use some really old projects that no one owns anymore so at least that part shouldn't be a sensitive issue. However, will this work? As I said most people have done C++ for a long time so my guess is that a) they'll sit there thinking why I'm telling them stuff they already know or b) they might actually take it as an insult because I'm telling them they don't know how to do the job they've been doing for years if not decades. Is there another approach which would reach broader audience than a code review would, but at the same time wouldn't feel like a punishment lecture? I'm not a fresh kid out of college who has utopian ideals of perfectly designed code and I don't expect that from anyone. The reason I'm writing this is because I just did a review of a person who actually had decent high-level design on paper. However if you picture classes: A - B - C - D, in the code B, C and D all implement almost the same public interface and B/C have one liner functions so that top-most class A is doing absolutely all the work (down to memory management, string parsing, setup negotiations...) primarily in 4 mongo methods and, for all intents and purposes, calls almost directly into D. Update: I'm a tech lead(6 months in this role) and do have full support of the group manager. We are working on a very mature product and maintenance costs are definitely letting themselves be known.

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  • Bridging 10GbE with 12.04 - bridging works but the bridging computer has no internet access

    - by Donal
    I have been trying to get 12.04 bridging working with two 10GbE cards. I have 2 10GbE cards in a linux box being used only for this bridge, 1 with 2 10GbaseT ports and another with a single CX4 port. I have 2 client computers connected with 10GbaseT cards and the CX4 card connects to a procurve switch. I can get the bridging happening mostly the way that I want, The clients receive dhcp information from the dhcp server (not the bridging machine) and can connect to and properly see the rest of the network. Speeds are ok, not amazing but working on that is another matter. My problem is that the bridging machine has no internet access ... meaning I can't update anything or apt-get anything It can ping all other machines on the local network. I've tried the helpful hints from: https://help.ubuntu.com/community/NetworkConnectionBridge "Enabling Internet Use on the Bridging Computer" and get the following RTNETLINK answers: File exists but dhclient br0 does nothing for me :( I think if it is anything it a multiple route problem as both br0 and eth4 have ipaddresses ... even though I have only set it up so that br0 has one ... Bridge setup details: /etc/network/interface auto br0 iface br0 inet static address 192.168.0.246 netmask 255.255.255.0 gateway 192.168.0.1 broadcast 192.168.0.255 dns-nameservers 192.168.0.1 dns-search example.com dns-domain example.com #(eth2 & eth3 are the 10GbaseT) #(eth4 is the CX4 connection) pre-up ip link set eth2 down pre-up ip link set eth3 down pre-up ip link set eth4 down pre-up brctl addbr br0 pre-up brctl addif br0 eth4 eth3 eth2 pre-up ip addr flush dev eth3 pre-up ip addr flush dev eth2 pre-up ip addr flush dev eth4 post-down ip link set eth4 down post-down ip link set eth2 down post-down ip link set eth3 down post-down ip link set br0 down post-down brctl delif br0 eth2 eth3 eth4 post-down brctl delbr br0 ifconfig -a br0 Link encap:Ethernet HWaddr 00:15:17:22:20:34 inet addr:192.168.0.102 Bcast:192.168.0.255 Mask:255.255.255.0 inet6 addr: fe80::215:17ff:fe22:2034/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:4957 errors:0 dropped:0 overruns:0 frame:0 TX packets:1077 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:596320 (596.3 KB) TX bytes:139952 (139.9 KB) eth4 Link encap:Ethernet HWaddr 00:60:dd:47:7c:05 inet addr:192.168.0.57 Bcast:192.168.0.255 Mask:255.255.255.0 inet6 addr: fe80::260:ddff:fe47:7c05/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:9000 Metric:1 RX packets:15391 errors:0 dropped:51 overruns:0 frame:0 TX packets:1207 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:5916769 (5.9 MB) TX bytes:154312 (154.3 KB) Interrupt:70 route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0 eth4 0.0.0.0 192.168.0.1 0.0.0.0 UG 100 0 0 br0 169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 br0 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 br0 192.168.0.0 0.0.0.0 255.255.255.0 U 1 0 0 eth4

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  • Layout of mathematical views (iOS)

    - by William Jockusch
    I am trying to figure out the right way to encapsulate graphical information about mathematical objects. It is not simple. For example, a matrix can include square brackets around its entries, or not. Some things carry down to sub-objects -- for example, a matrix might track the font size to be used by its entries. Similarly, the font color and the background color would carry down to the entries. Other things do not carry down. For example, the entries of the matrix do not need to know whether or not the matrix has those square brackets. Based on all of the above, I need to calculate sizes for everything, then frames. All of this can depend on the properties stored above. The size of a matrix depends on the sizes of its entries, and also on whether or not it has those brackets. What I am having a hard time with is not the individual ways to calculate sensible frames for this or that. It is the overall organizational structure of the whole thing. How can I keep track of it all without going crazy. One particular obstacle is worth mentioning -- for reasons I don't want to go into here, I need to calculate the sizes and frames for everything before I instantiate any actual views. So, for example, if I have a Matrix object, I need to calculate its size before I make a MatrixView. If I have an equation, I need to calculate the size of the view for the equation before I create the actual view. So I clearly need separate objects for those calculations. But I can't figure out a sensible class structure for those objects. If I put them all into a single class, I get some advantages because copying then becomes easy. But I also end up with a bloated class that contains info that is irrelevant for some objects -- such as whether or not to include those brackets around the matrix. But if I use a lot of different classes, copying properties becomes a real pain. If it matters, this is all in Objective C, for an iOS environment. Any pointers would be greatly appreciated.

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  • Understanding clojure keywords

    - by tjb1982
    I'm taking my first steps with Clojure. Otherwise, I'm somewhat competent with JavaScript, Python, Java, and a little C. I was reading this artical that describes destructuring vectors and maps. E.g. => (def point [0 0]) => (let [[x y] point] => (println "the coordinates are:" x y)) the coordinates are: 0 0 but I'm having a difficult time understanding keywords. At first glance, they seem really simple, as they just evaluate to themselves: => :test :test But they seem to be used is so many different ways and I don't understand how to think about them. E.g., you can also do stuff like this: => (defn full-name [& {first :first last :last}] => (println first last)) => (full-name :first "Tom" :last "Brennan") Tom Brennan nil This doesn't seem intuitive to me. I would have guessed the arguments should have been something more like: (full-name {:first "Tom" :last "Brennan"}) because it looks like in the function definition that you're saying "no required arguments, but a variable number of arguments comes in the form of a single map". But it seems more like you're saying "no required arguments, but a variable number of arguments comes which should be a list of alternating keywords and values... ?" I'm not really sure how to wrap my brain around this. Also, things like this confuse me too: => (def population {:humans 5 :zombies 1000}) => (:zombies population) 1000 => (population :zombies) 1000 How do maps and keywords suddenly become functions? If I could get some clarification on the use of keywords in these two examples, that would be really helpful. Update I've also seen http://stackoverflow.com/questions/3337888/clojure-named-arguments and while the accepted answer is a great demonstration of how to use keywords with destructuring and named arguments, I'm really looking more for understanding how to think about them--why the language is designed this way and how I can best internalize their use.

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  • Drawing lots of tiles with OpenGL, the modern way

    - by Nic
    I'm working on a small tile/sprite-based PC game with a team of people, and we're running into performance issues. The last time I used OpenGL was around 2004, so I've been teaching myself how to use the core profile, and I'm finding myself a little confused. I need to draw in the neighborhood of 250-750 48x48 tiles to the screen every frame, as well as maybe around 50 sprites. The tiles only change when a new level is loaded, and the sprites are changing all the time. Some of the tiles are made up of four 24x24 pieces, and most (but not all) of the sprites are the same size as the tiles. A lot of the tiles and sprites use alpha blending. Right now I'm doing all of this in immediate mode, which I know is a bad idea. All the same, when one of our team members tries to run it, he gets very bad frame rates (~20-30 fps), and it's much worse when there are more tiles, especially when a lot of those tiles are the kind that are cut into pieces. This all makes me think that the problem is the number of draw calls being made. I've thought of a few possible solutions to this, but I wanted to run them by some people who know what they're talking about so I don't waste my time on something stupid: TILES: When a level is loaded, draw all the tiles once into a frame buffer attached to a big honking texture, and just draw a big rectangle with that texture on it every frame. Put all the tiles into a static vertex buffer when the level is loaded, and draw them that way. I don't know if there's a way to draw objects with different textures with a single call to glDrawElements, or if this is even something I'd want to do. Maybe just put all the tiles into a big giant texture and use funny texture coordinates in the VBO? SPRITES: Draw each sprite with a separate call to glDrawElements. Use a dynamic VBO somehow. Same texture question as number 2 above. Point sprites? This is probably silly. Are any of these ideas sensible? Is there a good implementation somewhere I could look over?

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  • Is Infiniband going to get squeezed by iWARP and external QPI?

    - by andy.grover
    The Inquirer certainly thinks so.However, I'm not so sure it makes sense to compare Infiniband to an as-yet-unannounced optical external QPI. QPI is currently a processor interconnect. CPUs, RAM, and devices connected by it are conceptually part of the same machine -- they run a single OS, for example. They are both "networks" or "fabrics" but they have very different design trade-offs.Another widely-used bus in the system is closer to Infiniband than QPI -- PCI Express. Isn't it more likely that PCIe could take on IB? There are companies already who have solutions that use external PCI Express for cluster interconnect, but these have not gained significant market share. Why would QPI, a technology whose sweet spot is even further from Infiniband's than PCIe, be able to challenge Infiniband? It's hard to speculate without much information, but right now it doesn't seem likely to me.The other prediction made in the article is that Intel's 10GbE iWARP card could squeeze IB on the low end, due to its greater compatibility and lower cost.It's definitely never a good idea to bet against Ethernet when it comes to mass-market, commodity networking. Ethernet will win. 10GbE will win. But, there are now two competing ways to implement the low-latency RDMA Verbs interface on top of Ethernet. iWARP is essentially RDMA over TCP/IP over Ethernet. The new alternative is IBoE (Infiniband over Ethernet, aka RoCEE, aka "Rocky"). This encapsulates the IB packet protocol directly in the Ethernet frame. It loses the layer 3 routability of iWARP, but better maintains software compatibility with existing apps that use IB, and is simpler to implement in both software and hardware. iWARP has a substantial head start, but I believe that IBoE silicon will eventually be cheaper, and more likely to be implemented in commodity Ethernet hardware.I think IBoE is going to take low-end market share from traditional IB, but I think this is a situation IB hardware vendors have no problem accepting. Commoditized IBoE NICs invite greater use of RDMA features, and when higher performance is needed, customers can upgrade to "real" IB, maintaining IB's justification for higher prices. (IB max interconnect speeds have historically been 2-4x higher than Ethernet, and I don't see that changing.)(ObDisclosure: My current employer now sells IB hardware. I previously also worked at Intel. My opinions are my own, duh.)

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  • Push-Based Events in a Services Oriented Architecture

    - by Colin Morelli
    I have come to a point, in building a services oriented architecture (on top of Thrift), that I need to expose events and allow listeners. My initial thought was, "create an EventService" to handle publishing and subscribing to events. That EventService can use whatever implementation it desires to actually distribute the events. My client automatically round-robins service requests to available service hosts which are determined using Zookeeper-based service discovery. So, I'd probably use JMS inside of EventService mainly for the purpose of persisting messages (in the event that a service host for EventService goes down before it can distribute the message to all of the available listeners). When I started considering this, I began looking into the differences between Queues and Topics. Topics unfortunately won't work for me, because (at least for now), all listeners must receive the message (even if they were down at the time the event was pushed, or hadn't made a subscription yet because they haven't completed startup (during deployment, for example) - messages should be queued until the service is available). However, I don't want EventService to be responsible for handling all of the events. I don't think it should have the code to react to events inside of it. Each of the services should do what it needs with a given event. This would indicate that each service would need a JMS connection, which questions the value of having EventService at all (as the services could individually publish and subscribe to JMS directly). However, it also couples all of the services to JMS (when I'd rather that there be a single service that's responsible for determining how to distribute events). What I had thought was to publish an event to EventService, which pulls a configuration of listeners from some configuration source (database, flat file, irrelevant for now). It replicates the message and pushes each one back into a queue with information specific to that listener (so, if there are 3 listeners, 1 event would become 3 events in JMS). Then, another thread in EventService (which is replicated, running on multiple hots) would be pulling from the queue, attempting to make the service call to the "listener", and returning the message to the queue (if the service is down), or discarding the message (if the listener completed successfully). tl;dr If I have an EventService that is responsible for receiving events and delegating service calls to "event listeners," (which are really just endpoints on other services), how should it know how to craft the service call? Should I create a generic "Event" object that is shared among all services? Then, the EventService can just construct this object and pass it to the service call. Or is there a better answer to this problem entirely?

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  • SQL: empty string vs NULL value

    - by Jacek Prucia
    I know this subject is a bit controversial and there are a lot of various articles/opinions floating around the internet. Unfortunatelly, most of them assume the person doesn't know what the difference between NULL and empty string is. So they tell stories about surprising results with joins/aggregates and generally do a bit more advanced SQL lessons. By doing this, they absolutely miss the whole point and are therefore useless for me. So hopefully this question and all answers will move subject a bit forward. Let's suppose I have a table with personal information (name, birth, etc) where one of the columns is an email address with varchar type. We assume that for some reason some people might not want to provide an email address. When inserting such data (without email) into the table, there are two available choices: set cell to NULL or set it to empty string (''). Let's assume that I'm aware of all the technical implications of choosing one solution over another and I can create correct SQL queries for either scenario. The problem is even when both values differ on the technical level, they are exactly the same on logical level. After looking at NULL and '' I came to a single conclusion: I don't know email address of the guy. Also no matter how hard i tried, I was not able to sent an e-mail using either NULL or empty string, so apparently most SMTP servers out there agree with my logic. So i tend to use NULL where i don't know the value and consider empty string a bad thing. After some intense discussions with colleagues i came with two questions: am I right in assuming that using empty string for an unknown value is causing a database to "lie" about the facts? To be more precise: using SQL's idea of what is value and what is not, I might come to conclusion: we have e-mail address, just by finding out it is not null. But then later on, when trying to send e-mail I'll come to contradictory conclusion: no, we don't have e-mail address, that @!#$ Database must have been lying! Is there any logical scenario in which an empty string '' could be such a good carrier of important information (besides value and no value), which would be troublesome/inefficient to store by any other way (like additional column). I've seen many posts claiming that sometimes it's good to use empty string along with real values and NULLs, but so far haven't seen a scenario that would be logical (in terms of SQL/DB design). P.S. Some people will be tempted to answer, that it is just a matter of personal taste. I don't agree. To me it is a design decision with important consequences. So i'd like to see answers where opion about this is backed by some logical and/or technical reasons.

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  • Issues with shooting in a HTML5 platformer game

    - by fnx
    I'm coding a 2D sidescroller using only JavaScript and HTML5 canvas, and in my game I have two problems with shooting: 1) Player shoots continous stream of bullets. I want that player can shoot only a single bullet even though the shoot-button is being held down. 2) Also, I get an error "Uncaught TypeError: Cannot call method 'draw' of undefined" when all the bullets are removed. My shooting code goes like this: When player shoots, I do game.bullets.push(new Bullet(this, this.scale)); and after that: function Bullet(source, dir) { this.id = "bullet"; this.width = 10; this.height = 3; this.dir = dir; if (this.dir == 1) { this.x = source.x + source.width - 5; this.y = source.y + 16; } if (this.dir == -1) { this.x = source.x; this.y = source.y + 16; } } Bullet.prototype.update = function() { if (this.dir == 1) this.x += 8; if (this.dir == -1) this.x -= 8; for (var i in game.enemies) { checkCollisions(this, game.enemies[i]); } // Check if bullet leaves the viewport if (this.x < game.viewX * 32 || this.x > (game.viewX + game.tilesX) * 32) { removeFromList(game.bullets, this); } } Bullet.prototype.draw = function() { // bullet flipping uses orientation of the player var posX = game.player.scale == 1 ? this.x : (this.x + this.width) * -1; game.ctx.scale(game.player.scale, 1); game.ctx.drawImage(gameData.getGfx("bullet"), posX, this.y); } I handle removing with this function: function removeFromList(list, object) { for (i in list) { if (object == list[i]) { list.splice(i, 1); break; } } } And finally, in the main game loop I have this: for (var i in game.bullets) { game.bullets[i].update(); game.bullets[i].draw(); } I have tried adding if (game.bullets.length > 0) to the main game loop before the above draw&update calls, but I still get the same error.

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  • WebLogic Server 11gR1 Interactive Quick Reference

    - by JuergenKress
    The WebLogic Server 11gR1 Administration interactive quick reference is a multimedia tool for various terms and concepts used in WebLogic Server architecture. This tool is available for administrators for online or offline use. This is built as a multimedia web page which provides descriptions of WebLogic Server Architectural components, and references to relevant documentation. This tool offers valuable reference information for any complex concept or product in an intuitive and useful manner. Each interactive type presents data that may be available in the documentation (in the case of Oracle products), but presents it in a way that is more intuitive and useful to a user of Oracle products because it displays data the way it is used in a real world, best practice scenario. For example, the architectural diagram interactive type provides an image of an architectural diagram that is typically larger than a single slide or paper. The image is scrollable and provides zoom capabilities to easily and clearly view any part of the image. The image itself contains a hotspot map that you can click to get more information about a feature, including reference links to the documentation in question. Linking the visual image of the component and where it fits in the overall architecture of the product, or technology in use, to the technical explanation and how-to materials related to that component is something not offered by the documentation. In a future release, the poster will also enable you to drill down even further into the individual subsystems in nested diagrams to look at the details of that subsystem. In short, the interactive posters are good at showing you the big picture, then quickly and easily getting you to the detailed information you need. In an instant, you can see where a technical component fits into an overall architecture, and zero in on the nitty-gritty details that show you how to do it yourself. Note: This is a first initial release with more features in development. Currently known information: Only Firefox 8.0 and higher is known to work with this product. This product may work with Chrome and Safari browsers, but is known to have issues in Internet Explorer at this time. Smartphones, such as iPads and iPhones, are partially supported WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. BlogTwitterLinkedInMixForumWiki Technorati Tags: WebLogic server quick reference,weblogic overview,weblogic 12c,WebLogic Community,Oracle,OPN,Jürgen Kress

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  • Releasing the new Sample Browser Phone app

    - by Jialiang
    Originally posted on: http://geekswithblogs.net/Jialiang/archive/2014/06/05/releasing-the-new-sample-browser-phone-app.aspx Starting its journey in 2010, Sample Browser is achieving its tetralogy by releasing a Windows Phone version Sample Browser today. The new Windows Phone app is the fourth milestone of Sample Browser since we released the desktop version and the Visual Studio version in 2012 and the Windows Store version in 2013. This time, by providing a sample browser designed for a ‘walking’ platform in response to MVPs’ suggestions during last year’s MVP Global Summit, we are literally putting a world of code samples "at developers’ fingertips”. If you like to have a code gallery of over 7000 quality code samples in your pocket, then click here to download our Windows Phone Sample Browser and start a fantastic mobile experience. With Windows Phone version Sample Browser and the Internet, you can search for code samples on MSDN at anytime and anywhere you want, 24/7 and–even to bed. You can also check code sample details and share them with your friends. Compared to the other 3 pieces in the tetralogy (desktop version, Visual Studio version, and the Windows Store version), the Windows Phone version Sample Browser sells itself for convenience and instant connectivity. For those who need to reach code samples under mobile circumstances where no PCs is available, Windows Phone version Sample Browser will definitely be the right service you are seeking for. Aside from sharing samples via emails as the other 3 do, the Windows Phone version Sample Browser also allows you to share the sample via SMS and Near Field Communication (NFC).   What's Next Currently, the Windows Phone Sample Browser only supports online MSDN code searching, but we already plan to upgrade Sample Browser to allow users to do ‘Bing code search’, and add and manage their private code snippets.  We will also upgrade the app to universal app. Universal App is a new concept brought up in the Microsoft Build Developer Conference 2014. It is a new development model that allows for a single app to be deployed across multiple Windows devices such as Windows Phone, Windows 8.1, and XBox. Therefore, once we finish upgrading Sample Browser to a universal app, you can synchronize your own code snippets across different devices; You can also mark a code sample as favorite on your Windows Phone and continue to study the sample when you are on your desktop. By then, sharing data between platforms will be a piece of cake. Also, the user experience of Sample Browser on different platforms will be more consistent.  The best is yet to come!   We sincerely suggest you give Sample Browser a try (click here to download). If you love what you see in Sample Browser, please recommend it to your friends and colleagues. If you encounter any problems or have any suggestions for us, please contact us at [email protected]. Your precious opinions and comments are more than welcome.

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  • Why would you dual-run an app on Azure and AWS?

    - by Elton Stoneman
    Originally posted on: http://geekswithblogs.net/EltonStoneman/archive/2013/11/10/why-would-you-dual-run-an-app-on-azure-and-aws.aspxI had this question from a viewer of my Pluralsight course, Implementing the Reactive Manifesto with Azure and AWS, and thought I’d publish the response. So why would you dual-run your cloud app by hosting it on Azure and AWS? Sounds like a lot of extra development and management overhead. Well the most compelling reasons are reliability and portability. In 2012 I was working for a client who was making a big investment in the cloud, and at the end of the year we published their first external API for business partners. It was hosted in Azure and used some really nice features to route back into existing on-premise services. We were able to publish a clean, simple API to partners, and hide away the underlying complexity of the internal services while still leveraging them to do all the work. Two days after we went live, we were hit by the Azure SSL certificate expiry outage, and our API was unavailable for the best part of 3 days. Fortunately we had planned a gradual roll-out to partners, so the impact was minimal, but we’d been intending to ramp up quickly, and if the outage had happened a week or two later we would have been in a very bad place. Not least because our app could only run on Azure, we couldn’t package it up for another service without going back and reworking the code. More recently AWS had an issue with a networking device in one of their data centres which caused an outage that took the best part of a day to resolve. In both scenarios the SLAs are worthless, as you’ll get back a small percentage of your cloud expenditure, which is going to be negligible compared to your costs in dealing with the outage. And if your app is built specifically for AWS or Azure then if there’s an extended outage you can’t just deploy it onto a new set of kit from a different supplier. And the chances are pretty good there will be another extended outage, both for Microsoft and for Amazon. But the chances are small that it will happen to both at the same time. So my basic guidance has been: ignore the SLAs, go for better uptime by using two clouds. As soon as you need to scale beyond a single instance, start by scaling out to another cloud. Then scale out to different data centres in both clouds. Then you’ve got dual-cloud, quadruple-datacentre redundancy, so any more scaling you need can be left to the clouds to auto-scale themselves. By running in both clouds, you’ve made your app portable, so in the highly unlikely event that both AWS and Azure go down in multiple regions, you’ll have a deployment package which will let you spin up a new stack on yet another cloud, without having to rework your solution.

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  • Emaroo 1.4.0 Released

    - by WeigeltRo
    Emaroo is a free utility for browsing most recently used (MRU) lists of various applications. Quickly open files, jump to their folder in Windows Explorer, copy their path - all with just a few keystrokes or mouse clicks. tl;dr: Emaroo 1.4.0 is out, go download it on www.roland-weigelt.de/emaroo   Why Emaroo? Let me give you a few examples. Let’s assume you have pinned Emaroo to the first spot on the task bar so you can start it by hitting Win+1. To start one of the most recently used Visual Studio solutions you type Win+1, [maybe arrow key down a few times], Enter This means that you can start the most recent solution simply by Win+1, Enter What else? If you want to open an Explorer window at the file location of the solution, you type Ctrl+E instead of Enter.   If you know that the solution contains “foo” in its name, you can type “foo” to filter the list. Because this is not a general purpose search like e.g. the Search charm, but instead operates only on the MRU list of a single application, you usually have to type only a few characters until you can press Enter or Ctrl+E.   Ctrl+C copies the file path of the selected MRU item, Ctrl+Shift+C copies the directory If you have several versions of Visual Studio installed, the context menu lets you open a solution in a higher version.   Using the context menu, you can open a Visual Studio solution in Blend. So far I have only mentioned Visual Studio, but Emaroo knows about other applications, too. It remembers the last application you used, you can change between applications with the left/right arrow or accelerator keys. Press F1 or click the Emaroo icon (the tab to the right) for a quick reference. Which applications does Emaroo know about? Emaroo knows the MRU lists of Visual Studio 2008/2010/2012/2013 Expression Blend 4, Blend for Visual Studio 2012, Blend for Visual Studio 2013 Microsoft Word 2007/2010/2013 Microsoft Excel 2007/2010/2013 Microsoft PowerPoint 2007/2010/2013 Photoshop CS6 IrfanView (most recently used directories) Windows Explorer (directories most recently typed into the address bar) Applications that are not installed aren’t shown, of course. Where can I download it? On the Emaroo website: www.roland-weigelt.de/emaroo Have fun!

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  • Exalogic 2.0.1 Tea Break Snippets - Creating and using Distribution Groups

    - by The Old Toxophilist
    By default running your Exalogic in a Virtual provides you with, what to Cloud Users, is a single large resource and they can just create vServers and not care about how they are laid down on the the underlying infrastructure. All the Cloud Users will know is that they can create vServers. For example if we have a Quarter Rack (8 Nodes) and our Cloud User creates 8 vServers those 8 vServers may run on 8 distinct nodes or may all run on the same node. Although in many cases we, as Cloud Users, may not be to worried how the Virtualisation Algorithm decides where to place our vServers there are cases where it is extremely important that vServers run on distinct physical compute nodes. For example if we have a Weblogic Cluster we will want the Servers with in the cluster to run on distinct physical node to cover for the situation where one physical node is lost. To achieve this the Exalogic Virtualised implementation provides Distribution Groups that define and anti-aliasing policy that the underlying Virtualisation Algorithm will take into account when placing vServers. It should be noted that Distribution Groups must be created before you create vServers because a vServer can only be added to a Distribution Group at creation time. Creating A Distribution Group To create a Distribution Groups we will first need to select the Account in which we want the Distribution Group to be created. Once we have selected the account we will see the Interface update and Account specific Actions will be displayed within the Action Panes. From the Action pane (or Right-Click on the Account) select the "Create Distribution Group" action. This will initiate the create wizard as follows. Distribution Group Details Within the first Step of the Wizard we can specify the name of the distribution group and this should be unique. In addition we can provide a detailed description of the group. Distribution Group Configuration The second step of the configuration wizard allows you to specify the number of elements that are required within this group and will specify a maximum of the number of nodes within you Exalogic. At this point it is always better to specify a group with spare capacity allowing for future expansion. As vServers are added to group the available slots decrease. Summary Finally the last step of the wizard display a summary of the information entered.

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  • Creating a voxel chunk with a VBO - How to translate the coordinates of each block and add it to the VBO chunk?

    - by sunsunsunsunsun
    Im trying to make a voxel engine similar to minecraft as a little learning experience and a way to learn some opengl. I have created a chunk class and I want to put all of the vertices for the whole chunk into a single VBO. I was previously only putting each block into a vbo and making a call to render each block. Anyways, I am a bit confused about how I can translate the coordinates of each block in the chunk when I'm putting all vertices into one vbo. This is what I have at the moment. public void putVertices(float tx, float ty, float tz) { float l_length = 1.0f; float l_height = 1.0f; float l_width = 1.0f; vertexPositionData.put(new float[]{ xOffset + l_length + tx, l_height + ty, zOffset + -l_width + tz, xOffset + -l_length + tx, l_height + ty, zOffset + -l_width + tz, xOffset + -l_length + tx, l_height + ty, zOffset + l_width + tz, xOffset + l_length + tx, l_height + ty, zOffset + l_width + tz, xOffset + l_length + tx, -l_height + ty, zOffset + l_width + tz, xOffset + -l_length + tx, -l_height + ty, zOffset + l_width + tz, xOffset + -l_length + tx, -l_height + ty, zOffset + -l_width + tz, xOffset + l_length + tx, -l_height + ty, zOffset + -l_width + tz, xOffset + l_length + tx, l_height + ty, zOffset + l_width + tz, xOffset + -l_length + tx, l_height + ty,zOffset + l_width + tz, xOffset + -l_length + tx, -l_height + ty,zOffset + l_width + tz, xOffset + l_length + tx, -l_height + ty, zOffset + l_width + tz, xOffset + l_length + tx, -l_height + ty, zOffset + -l_width + tz, xOffset + -l_length + tx, -l_height + ty,zOffset + -l_width + tz, xOffset + -l_length + tx, l_height + ty, zOffset + -l_width + tz, xOffset + l_length + tx, l_height + ty, zOffset + -l_width + tz, xOffset + -l_length + tx, l_height + ty, zOffset + l_width + tz, xOffset + -l_length + tx, l_height + ty, zOffset + -l_width + tz, xOffset + -l_length + tx, -l_height + ty, zOffset + -l_width + tz, xOffset + -l_length + tx, -l_height + ty,zOffset + l_width + tz, xOffset + l_length + tx, l_height + ty,zOffset + -l_width + tz, xOffset + l_length + tx, l_height + ty, zOffset + l_width + tz, xOffset + l_length + tx, -l_height + ty, zOffset + l_width + tz, xOffset + l_length + tx, -l_height + ty, zOffset + -l_width + tz }); } public void createChunk() { vertexPositionData = BufferUtils.createFloatBuffer((24*3)*activateBlocks); Random random = new Random(); for (int x = 0; x < CHUNK_SIZE; x++) { for (int y = 0; y < CHUNK_SIZE; y++) { for (int z = 0; z < CHUNK_SIZE; z++) { if(blocks[x][y][z].getActive()) { putVertices(x*2.0f, y*2.0f, z*2.0f); } } } } Whats any easy way to translate the vertices of each block into its correct position? I was previously using glTranslatef with each call to render block but this wont work now. What I am doing now also does not work, the blocks all render in stacks on top of each other and it looks like this: http://i.imgur.com/NyFtBTI.png Thanks

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  • Why is my laptop so sluggish? Or Damn You Facebook and Twitter! Or All Hail Chrome!

    - by John Conwell
    In the past three weeks, I've noticed that my laptop (dual core 2.1GHz, 2Gb RAM) has become amazingly sluggish.  I only uses for communications and data lookup workflows, so the slowness was tolerable.  But today I finally got fed up with the suckyness and decided to get to the root of the problem (I do have strong performance roots after all). It actually didn't take all that long to figure it out.  About a year ago I converted to Google Chrome (away from FireFox).  One of the great tools Chrome has is a "Task Manager" tool, that gives you Windows Task Manager like details for all the tabs open in the browser (Shift + Esc).  Since every tab runs in its own process, its easy from Task Manager (both Windows or Chrome) to identify and kill a single performance offending tab.  This is unlike IE, where you only get aggregate data about all tabs open.  Anyway, I digress.  Today my laptop sucked.  Windows Task Manager told me that I had two memory hogging Chrome tabs, but couldn't tell me which web page those tabs are showing.  Enter Chrome Task Manager which tells you the page title, along with CPU, memory and network utilization of each tab.  Enter my amazement.  Turns out Facebook was using just shy of half a Gb of RAM.  Half a Gigabyte!  That's 512 Megabytes!524,288 Kilobytes! 536,870,912 Bytes!  Or 4,294,967,296 Bits!  In other words, that's a frackin boat load of memory.  Now consider that Facebook is running on pretty much 96.3% (statistics based on absolutely nothing) of every house hold desktop, laptop, netbook, and mobile device in America, that is pretty horrific! And I wasn't playing any Facebook games like FarmWars or MafiaVille.  I just had my normal, default home page up showing me who just had breakfast, or just got finished with their morning run. I'm sorry...let me say that again...HALF A GIG OF RAM!  That is just unforgivable. I can just see my mom calling me up:  Mom: "John...I think I need a new computer.  Mine is really slow these days" John: "What do you have running?" Mom: "Oh, just Facebook" John: "Ok, close Facebook and tell me how fast your computer feels" Mom: "Well...I don't know how fast it is.  All I do is use Facebook" John: "Ok Mom, I'll send you a new computer by Tuesday" Oh yea...and the other offending web page?  It was Twitter, using a quarter of a Gigabyte. God I love social networks!

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  • Is it evil to model JSON responses to classes when they are mostly smilar?

    - by Aybe
    Here's the problem : While implementing a C# wrapper for an online API (Discogs) I've been faced to a dilemma : quite often the responses returned have mostly similar members and while modeling these responses to classes, some questions surfaces on which way to go would be the best. Example : Querying for a 'release' or a 'master' will return an object that contains an array of 'artist', however these 'artists' do not exactly have the same members. Currently I decided to represent these 'artists' as a single 'Artist' class, against having respective 'ReleaseArtist' and 'MasterArtist' classes which soon becomes very confusing even though another problem arises : when a category (master or release) does not return these members, they will be null. Though it might sound confusing as well I find it less confusing than the former situation as I've tackled the problem by simply not showing null members when visualizing these objects. Is this the right approach to follow ? An example of these differences : public class Artist { public List<Alias> Aliases { get; set; } public string DataQuality { get; set; } public List<Image> Images { get; set; } public string Name { get; set; } public List<string> NameVariations { get; set; } public string Profile { get; set; } public string Realname { get; set; } public string ReleasesUrl { get; set; } public string ResourceUrl { get; set; } public string Uri { get; set; } public List<string> Urls { get; set; } } public class ReleaseArtist { public string Join { get; set; } public string Name { get; set; } public string Anv { get; set; } public string Tracks { get; set; } public string Role { get; set; } public string ResourceUrl { get; set; } public int Id { get; set; } }

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  • At $20/month Windows Azure host my website with 99.97% uptime

    - by Gopinath
    Couple of years ago a reliable and decent performing Windows hosting was not affordable to many enthusiastic developers who want to try a startup idea or build a hobby site. I tried to start an ASP.NET website few years ago to provide services like – Mobile Tracing, Vehicle Tracing. But due to high cost of Windows hosting I developed those services using PHP (not an easy task for .NET developer) and hosted on them Linux servers.  But with recent evolution of Windows Azure, hosting ASP.NET websites on highly reliable servers is affordable. Today anyone can host a high responsive and available ASP.NET website for just $20/month using Windows Azure. My website coziie.com is running on Windows Azure and serves close to quarter millions visitors a month with 99.97% of uptime and most of the page load times are less than 3 seconds. All I spend to run this website is just around $20, if you translate it to India rupees its roughly Rs.1000. The web sever of coziie.com is powered by a single Extra Small Web role instance and the backend is powered by a SQL Azure instance. Azure is quite impressive to provide 99.97% of uptime. Response times during peak are around 3 seconds and on nomarl loads it is around 1.5 seconds. Here is the report of uptime provided by Royal Pingdom over last one year For just $20/month Windows Azure takes care of the following apart from hosting Patches up Windows OS to the latest version Upgrades ASP.NET to the latest version – coziie.com is running on ASP.NET MVC 3 and soon I’ll upgrade it to ASP.NET MVC 4 Hosts data on latest and best version Sql Server database SQL Azure maintains 3 copies of database and automatically recovers in case of server failures and disasters. I never worry about database backups/restore. Provides staging environment for deploying applications for testing purpose and move them to production – I upgrade  twice a month on average With Windows Azure I no longer focus on server maintenance or data backups. They are taken up by Microsoft team and I just focus on building my website. Wish there is a low cost Linux version of Windows Azure so that I can stop worrying about server maintenance of this blog!! If you are looking for a Windows hosting, look no further than Windows Azure. If you find $20/month is a bit expensive to start with you may explore Azure Website (sort of shared hosted environment) which is free to start with and as your traffic grows you can move to paid hosting.

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  • Design pattern to handle queries using multiple models

    - by coderkane
    I am presented with a dilemma while trying to re-designing the class structure for my PHP/MySQL application to make it more elegant and conform it to the SOLID principle. The problem goes like this: Let as assume, there is an abstract class called person which has certain properties to define a generic person, such as name, age, date of birth etc. There are two classes, student, and teacher, that implements this abstract class. They add their own unique properties to it. I have designed all the three classes to include all the operational logic (details of which are not relevant in context of the question). Now, I need to create views/reports/data grids which contain details from multiple classes, for example, say, a list of all students doing projects in Chemistry mentored by a teacher whose name is the parameter to the query. This is just one example of a view, there are many different views in the application, which uses data from 3-4 tables, and each of them have multiple input parameters to generate them. Considering this particular example, I have written the relevant query using JOIN and the results are as expected and proper, now here is the dilemma: Keeping in mind the single responsibility principle, where should I keep this query? It does not belong to either Student class, or Teacher class or any other classes currently present. a) Should I create a new class, say dataView class, and design it as a MVC pattern and keep the query there? What about the other views? how do they fit in this architecture? b) Should I not keep the query in code at all, and make it DB View ? c) Am I completely wrong in the approach? If so what is the right approach? My considerations are as follows: a) should be easy to add new views later on if requirement comes, without having to copy-paste-modify code b) would like to make it as loosely coupled as possible so that if minor db structure changes happen, it does not break I did google searches on report design and OOP report generators, but all the result seem to focus on the visual design of the report rather than fetching the data. I have already taken care of the visual aspect of the report using MVC with html templates. I am sure this is a very fundamental problem with known solution, but I am somehow not able to find it (maybe searching with wrong keyword). Edit1: Modified the title to make it more relevant Edit2: The accepted answer got me thinking in the right direction and identify my design flaws, which eventually led me to find this question and the solution in Stack Overflow which gave me the detailed answer to clear the confusion.

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  • How to make a queue switches from FIFO mode to priority mode?

    - by enzom83
    I would like to implement a queue capable of operating both in the FIFO mode and in the priority mode. This is a message queue, and the priority is first of all based on the message type: for example, if the messages of A type have higher priority than the messages of the B type, as a consequence all messages of A type are dequeued first, and finally the messages of B type are dequeued. Priority mode: my idea consists of using multiple queues, one for each type of message; in this way, I can manage a priority based on the message type: just take first the messages from the queue at a higher priority and progressively from lower priority queues. FIFO mode: how to handle FIFO mode using multiple queues? In other words, the user does not see multiple queues, but it uses the queue as if it were a single queue, so that the messages leave the queue in the order they arrive when the priority mode is disabled. In order to achieve this second goal I have thought to use a further queue to manage the order of arrival of the types of messages: let me explain better with the following code snippet. int NUMBER_OF_MESSAGE_TYPES = 4; int CAPACITY = 50; Queue[] internalQueues = new Queue[NUMBER_OF_MESSAGE_TYPES]; Queue<int> queueIndexes = new Queue<int>(CAPACITY); void Enqueue(object message) { int index = ... // the destination queue (ie its index) is chosen according to the type of message. internalQueues[index].Enqueue(message); queueIndexes.Enqueue(index); } object Dequeue() { if (fifo_mode_enabled) { // What is the next type that has been enqueued? int index = queueIndexes.Dequeue(); return internalQueues[index].Dequeue(); } if (priority_mode_enabled) { for(int i=0; i < NUMBER_OF_MESSAGE_TYPES; i++) { int currentQueueIndex = i; if (!internalQueues[currentQueueIndex].IsEmpty()) { object result = internalQueues[currentQueueIndex].Dequeue(); // The following statement is fundamental to a subsequent switching // from priority mode to FIFO mode: the messages that have not been // dequeued (since they had lower priority) remain in the order in // which they were queued. queueIndexes.RemoveFirstOccurrence(currentQueueIndex); return result; } } } } What do you think about this idea? Are there better or more simple implementations?

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  • Dealing with coworkers when developing, need advice [closed]

    - by Yippie-Kai-Yay
    I developed our current project architecture and started developing it on my own (reaching something like, revision 40). We're developing a simple subway routing framework and my design seemed to be done extremely well - several main models, corresponding views, main logic and data structures were modeled "as they should be" and fully separated from rendering, algorithmic part was also implemented apart from the main models and had a minor number of intersection points. I would call that design scalable, customizable, easy-to-implement, interacting mostly based on the "black box interaction" and, well, very nice. Now, what was done: I started some implementations of the corresponding interfaces, ported some convenient libraries and wrote implementation stubs for some application parts. I had the document describing coding style and examples of that coding style usage (my own written code). I forced the usage of more or less modern C++ development techniques, including no-delete code (wrapped via smart pointers) and etc. I documented the purpose of concrete interface implementations and how they should be used. Unit tests (mostly, integration tests, because there wasn't a lot of "actual" code) and a set of mocks for all the core abstractions. I was absent for 12 days. What do we have now (the project was developed by 4 other members of the team): 3 different coding styles all over the project (I guess, two of them agreed to use the same style :), same applies to the naming of our abstractions (e.g CommonPathData.h, SubwaySchemeStructures.h), which are basically headers declaring some data structures. Absolute lack of documentation for the recently implemented parts. What I could recently call a single-purpose-abstraction now handles at least 2 different types of events, has tight coupling with other parts and so on. Half of the used interfaces now contain member variables (sic!). Raw pointer usage almost everywhere. Unit tests disabled, because "(Rev.57) They are unnecessary for this project". ... (that's probably not everything). Commit history shows that my design was interpreted as an overkill and people started combining it with personal bicycles and reimplemented wheels and then had problems integrating code chunks. Now - the project still does only a small amount of what it has to do, we have severe integration problems, I assume some memory leaks. Is there anything possible to do in this case? I do realize that all my efforts didn't have any benefit, but the deadline is pretty soon and we have to do something. Did someone have a similar situation? Basically I thought that a good (well, I did everything that I could) start for the project would probably lead to something nice, however, I understand that I'm wrong. Any advice would be appreciated, sorry for my bad english.

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  • design a model for a system of dependent variables

    - by dbaseman
    I'm dealing with a modeling system (financial) that has dozens of variables. Some of the variables are independent, and function as inputs to the system; most of them are calculated from other variables (independent and calculated) in the system. What I'm looking for is a clean, elegant way to: define the function of each dependent variable in the system trigger a re-calculation, whenever a variable changes, of the variables that depend on it A naive way to do this would be to write a single class that implements INotifyPropertyChanged, and uses a massive case statement that lists out all the variable names x1, x2, ... xn on which others depend, and, whenever a variable xi changes, triggers a recalculation of each of that variable's dependencies. I feel that this naive approach is flawed, and that there must be a cleaner way. I started down the path of defining a CalculationManager<TModel> class, which would be used (in a simple example) something like as follows: public class Model : INotifyPropertyChanged { private CalculationManager<Model> _calculationManager = new CalculationManager<Model>(); // each setter triggers a "PropertyChanged" event public double? Height { get; set; } public double? Weight { get; set; } public double? BMI { get; set; } public Model() { _calculationManager.DefineDependency<double?>( forProperty: model => model.BMI, usingCalculation: (height, weight) => weight / Math.Pow(height, 2), withInputs: model => model.Height, model.Weight); } // INotifyPropertyChanged implementation here } I won't reproduce CalculationManager<TModel> here, but the basic idea is that it sets up a dependency map, listens for PropertyChanged events, and updates dependent properties as needed. I still feel that I'm missing something major here, and that this isn't the right approach: the (mis)use of INotifyPropertyChanged seems to me like a code smell the withInputs parameter is defined as params Expression<Func<TModel, T>>[] args, which means that the argument list of usingCalculation is not checked at compile time the argument list (weight, height) is redundantly defined in both usingCalculation and withInputs I am sure that this kind of system of dependent variables must be common in computational mathematics, physics, finance, and other fields. Does someone know of an established set of ideas that deal with what I'm grasping at here? Would this be a suitable application for a functional language like F#? Edit More context: The model currently exists in an Excel spreadsheet, and is being migrated to a C# application. It is run on-demand, and the variables can be modified by the user from the application's UI. Its purpose is to retrieve variables that the business is interested in, given current inputs from the markets, and model parameters set by the business.

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  • Workflow 4.5 is Awesome, cant wait for 5.0!

    - by JoshReuben
    About 2 years ago I wrote a blog post describing what I would like to see in Workflow vnext: http://geekswithblogs.net/JoshReuben/archive/2010/08/25/workflow-4.0---not-there-yet.aspx At the time WF 4.0 was a little rough around the edges – the State Machine was on codeplex and people were simulating state machines with Flowcharts. Last year I built a near- realtime machine management system using WF 4.0.1 – its managing the internal operations of this device: http://landanano.com/products/commercial   Well WF 4.5 has come a long way – many of my gripes have been addressed: C# expressions - no more VB 'AndAlso' clauses state machine awesomeness - can query current state many designer improvements - Document Outline is so much more succinct than Designer! Separate WCF Service Contract interfaces and ability to generate activities from contract operations ability to rehydrate to updated flow definitions via DynamicUpdateMap and WorkflowIdentity you can read about the new features here: http://msdn.microsoft.com/en-us/library/hh305677(VS.110).aspx   2013 could be the year of Workflow evangelism for .NET, as it comes together as the DSL language. Eg on Azure it could be used to graphically orchestrate between WebRoles, WorkerRoles and AppFabric Queues and the ServiceBus – that would be grand.   Here’s a list of things I’d like to see in Workflow 5.0: Stronger Parallelism support for true multithreaded workflows . A Workflow executes on a single thread – wouldn’t it be great if we had the ability to model TPL DataFlow? Parallel is not really parallel, just allows AsyncCodeActivity.     support for recursion an ExpressionTree activity with an editor design surface a math activity pack return of application level protocol (3.51 WF services) – automatically expose a state machine as a WCF service with bookmark Receive activities generated from OperationContract automatically placed in state transition triggers. A new HTML5 ActivityDesigner control – support with different CSS3  skinnable hooks,  remote connectivity (had to roll my own) A data flow view – crucial to understanding the big picture Ability to refactor a Sequence to custom activity in a separate .xaml file – like Expression Blend does for UserControl state machine global error handling - if all states goto an error state, you quickly get visual spagetti. Now you could nest a state machine, but what if you want an application level protocol whereby each state exposes certain WCF ops. DSL RAD editing - Make the Document Outline into a DSL editor for adding activities  – For WF to really succeed as a higher level of abstraction, It needs to be more productive than raw coding - drag & drop on the designer is currently too slow compared to just typing code. Extensible Wizard API - for pluggable WF editor experience other execution models beyond Sequence, Flowchart & StateMachine: SSIS, Behavior Trees,  Wolfram Model tool – surprise us! improvements to Designer debugging API - SourceLocation is tied to XAML file line number and char position, and ModelService access seems convoluted - why not leverage WPF LogicalTreeHelper / VisualTreeHelper ? Workflow Team , keep on rocking!

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  • SQL SERVER – Fix: Error: 147 An aggregate may not appear in the WHERE clause unless it is in a subquery contained in a HAVING clause or a select list, and the column being aggregated is an outer reference

    - by pinaldave
    Everybody was beginner once and I always like to get involved in the questions from beginners. There is a big difference between the question from beginner and question from advanced user. I have noticed that if an advanced user gets an error, they usually need just a small hint to resolve the problem. However, when a beginner gets error he sometimes sits on the error for a long time as he/she has no idea about how to solve the problem as well have no idea regarding what is the capability of the product. I recently received a very novice level question. When I received the problem I quickly see how the user was stuck. When I replied him with the solution, he wrote a long email explaining how he was not able to solve the problem. He thanked multiple times in the email. This whole thing inspired me to write this quick blog post. I have modified the user’s question to match the code with AdventureWorks as well simplified so it contains the core content which I wanted to discuss. Problem Statement: Find all the details of SalesOrderHeaders for the latest ShipDate. He comes up with following T-SQL Query: SELECT * FROM [Sales].[SalesOrderHeader] WHERE ShipDate = MAX(ShipDate) GO When he executed above script it gave him following error: Msg 147, Level 15, State 1, Line 3 An aggregate may not appear in the WHERE clause unless it is in a subquery contained in a HAVING clause or a select list, and the column being aggregated is an outer reference. He was not able to resolve this problem, even though the solution was given in the query description itself. Due to lack of experience he came up with another version of above query based on the error message. SELECT * FROM [Sales].[SalesOrderHeader] HAVING ShipDate = MAX(ShipDate) GO When he ran above query it produced another error. Msg 8121, Level 16, State 1, Line 3 Column ‘Sales.SalesOrderHeader.ShipDate’ is invalid in the HAVING clause because it is not contained in either an aggregate function or the GROUP BY clause. What he wanted actually was the SalesOrderHeader all the Sales shipped on the last day. Based on the problem statement what the right solution is as following, which does not generate error. SELECT * FROM [Sales].[SalesOrderHeader] WHERE ShipDate = (SELECT MAX(ShipDate) FROM [Sales].[SalesOrderHeader]) Well, that’s it! Very simple. With SQL Server there are always multiple solution to a single problem. Is there any other solution available to the problem stated? Please share in the comment. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Error Messages, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • ArchBeat Link-o-Rama for 2012-08-29

    - by Bob Rhubart
    ORCLville: OOW 2012 - Crystal BallOracle ACE Director Floyd Teter cooks up some tongue-in-cheek predictions for news and announcements that might come out of Oracle OpenWorld 2012. What's your prediction? Oracle Optimized Solutions at Oracle OpenWorld 2012 | Oracle Hardware Hardware matters, too! The people behind the Oracle Hardware blog have put together a list of Oracle Openworld 2012 sessions focused Oracle Optimized Solutions, "designed, pre-tested, tuned and fully documented architectures for optimal performance and availability." Just plug the session ID numbers into Schedule Builder and you're good to go. AIX Checklist for stable OBIEE deployment | Dick Dunbar "OBIEE is a complicated system with many moving parts and connection points," according to Oracle Business Inteligence escalation engineer Dick Dunbar. "The purpose of this article is to provide a checklist to discuss OBIEE deployment with your systems administrators." Demo for OPN: Coherence Management with EM Cloud Control 12c Oracle Partner Network members can check out a new Coherence Management demo that showcases some of the key capabilities of Management Pack for Oracle Coherence and JVM Diagnostics. "The demo flow showcases the key enhancements made in Enterprise Manager 12c release which includes new customizable performance summary, cache data management and configuration management," according to the WebLogic Partner Community EMEA blog. The Pragmatic Architect: To Boldly Go Where No One Has Gone Before | Frank Buschmann "Many architects have technical knowledge that's both impressive and sound, which is indeed an inevitable basis for design success," says Frank Buschmann. "Yet, a lot of software projects fail or suffer due to severe challenges in their architecture. The key to mastery is how architects approach design, what they value, and where they focus their attention and work." As retail dies, whom will be the winners? | Peter Evans-Greenwood "The problem for many retailers is that how consumers shop has changed but the the retailers haven't adapted, " says Peter Evans-Greenwood. "Their sole virtue was to be the last step in a supply chain delivering somebody else's products to the consumer. However, being the last step in the supply chain is no longer a virtue when consumers skip across channels and can reach around the globe, no longer dependant on or limited to what they can find locally." Thought for the Day "Brains require stimulation. If you're locked into a pattern of work, work, and more work, your brain soon habituates - the same way that it lets you stop hearing a clock ticking. So, if you want to be more effective at work, you must, paradoxically, be less single-minded in your devotion to work. Anything you do—anything—that stimulates new segments of your brain will make you a more effective programmer or analyst. I promise, with a money-back guarantee." — Gerald M. Weinberg Source: SoftwareQuotes.com

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