Search Results

Search found 11396 results on 456 pages for 'simply denis'.

Page 388/456 | < Previous Page | 384 385 386 387 388 389 390 391 392 393 394 395  | Next Page >

  • Getting Started with Cloud Computing

    - by juanlarios
    You’ve likely heard about how Office 365 and Windows Intune are great applications to get you started with Cloud Computing. Many of you emailed me asking for more info on what Cloud Computing is, including the distinction between "Public Cloud" and "Private Cloud". I want to address these questions and help you get started. Let's begin with a brief set of definitions and some places to find more info; however, an excellent place where you can always learn more about Cloud Computing is the Microsoft Virtual Academy. Public Cloud computing means that the infrastructure to run and manage the applications users are taking advantage of is run by someone else and not you. In other words, you do not buy the hardware or software to run your email or other services being used in your organization – that is done by someone else. Users simply connect to these services from their computers and you pay a monthly subscription fee for each user that is taking advantage of the service. Examples of Public Cloud services include Office 365, Windows Intune, Microsoft Dynamics CRM Online, Hotmail, and others. Private Cloud computing generally means that the hardware and software to run services used by your organization is run on your premises, with the ability for business groups to self-provision the services they need based on rules established by the IT department. Generally, Private Cloud implementations today are found in larger organizations but they are also viable for small and medium-sized businesses since they generally allow an automation of services and reduction in IT workloads when properly implemented. Having the right management tools, like System Center 2012, to implement and operate Private Cloud is important in order to be successful. So – how do you get started? The first step is to determine what makes the most sense to your organization. The nice thing is that you do not need to pick Public or Private Cloud – you can use elements of both where it makes sense for your business – the choice is yours. When you are ready to try and purchase Public Cloud technologies, the Microsoft Volume Licensing web site is a good place to find links to each of the online services. In particular, if you are interested in a trial for each service, you can visit the following pages: Office 365, CRM Online, Windows Intune, and Windows Azure. For Private Cloud technologies, start with some of the courses on Microsoft Virtual Academy and then download and install the Microsoft Private Cloud technologies including Windows Server 2008 R2 Hyper-V and System Center 2012 in your own environment and take it for a spin. Also, keep up to date with the Canadian IT Pro blog to learn about events Microsoft is delivering such as the IT Virtualization Boot Camps and more to get you started with these technologies hands on. Finally, I want to ask for your help to allow the team at Microsoft to continue to provide you what you need. Twice a year through something we call "The Global Relationship Study" – they reach out and contact you to see how they're doing and what Microsoft could do better. If you get an email from "Microsoft Feedback" with the subject line "Help Microsoft Focus on Customers and Partners" between March 5th and April 13th, please take a little time to tell them what you think. Cloud Computing Resources: Microsoft Server and Cloud Computing site – information on Microsoft's overall cloud strategy and products. Microsoft Virtual Academy – for free online training to help improve your IT skillset. Office 365 Trial/Info page – get more information or try it out for yourself. Office 365 Videos – see how businesses like yours have used Office 365 to transition to the cloud. Windows Intune Trial/Info – get more information or try it out for yourself. Microsoft Dynamics CRM Online page – information on trying and licensing Microsoft Dynamics CRM Online. Additional Resources You May Find Useful: Springboard Series Your destination for technical resources, free tools and expert guidance to ease the deployment and management of your Windows-based client infrastructure. TechNet Evaluation Center Try some of our latest Microsoft products for free, Like System Center 2012 Pre-Release Products, and evaluate them before you buy. AlignIT Manager Tech Talk Series A monthly streamed video series with a range of topics for both infrastructure and development managers. Ask questions and participate real-time or watch the on-demand recording. Tech·Days Online Discover what's next in technology and innovation with Tech·Days session recordings, hands-on labs and Tech·Days TV.

    Read the article

  • Why is x=x++ undefined?

    - by ugoren
    It's undefined because the it modifies x twice between sequence points. The standard says it's undefined, therefore it's undefined. That much I know. But why? My understanding is that forbidding this allows compilers to optimize better. This could have made sense when C was invented, but now seems like a weak argument. If we were to reinvent C today, would we do it this way, or can it be done better? Or maybe there's a deeper problem, that makes it hard to define consistent rules for such expressions, so it's best to forbid them? So suppose we were to reinvent C today. I'd like to suggest simple rules for expressions such as x=x++, which seem to me to work better than the existing rules. I'd like to get your opinion on the suggested rules compared to the existing ones, or other suggestions. Suggested Rules: Between sequence points, order of evaluation is unspecified. Side effects take place immediately. There's no undefined behavior involved. Expressions evaluate to this value or that, but surely won't format your hard disk (strangely, I've never seen an implementation where x=x++ formats the hard disk). Example Expressions x=x++ - Well defined, doesn't change x. First, x is incremented (immediately when x++ is evaluated), then it's old value is stored in x. x++ + ++x - Increments x twice, evaluates to 2*x+2. Though either side may be evaluated first, the result is either x + (x+2) (left side first) or (x+1) + (x+1) (right side first). x = x + (x=3) - Unspecified, x set to either x+3 or 6. If the right side is evaluated first, it's x+3. It's also possible that x=3 is evaluated first, so it's 3+3. In either case, the x=3 assignment happens immediately when x=3 is evaluated, so the value stored is overwritten by the other assignment. x+=(x=3) - Well defined, sets x to 6. You could argue that this is just shorthand for the expression above. But I'd say that += must be executed after x=3, and not in two parts (read x, evaluate x=3, add and store new value). What's the Advantage? Some comments raised this good point. It's not that I'm after the pleasure of using x=x++ in my code. It's a strange and misleading expression. What I want is to be able to understand complicated expressions. Normally, a complicated expression is no more than the sum of its parts. If you understand the parts and the operators combining them, you can understand the whole. C's current behavior seems to deviate from this principle. One assignment plus another assignment suddenly doesn't make two assignments. Today, when I look at x=x++, I can't say what it does. With my suggested rules, I can, by simply examining its components and their relations.

    Read the article

  • How'd they do it: Millions of tiles in Terraria

    - by William 'MindWorX' Mariager
    I've been working up a game engine similar to Terraria, mostly as a challenge, and while I've figured out most of it, I can't really seem to wrap my head around how they handle the millions of interactable/harvestable tiles the game has at one time. Creating around 500.000 tiles, that is 1/20th of what's possible in Terraria, in my engine causes the frame-rate to drop from 60 to around 20, even tho I'm still only rendering the tiles in view. Mind you, I'm not doing anything with the tiles, only keeping them in memory. Update: Code added to show how I do things. This is part of a class, which handles the tiles and draws them. I'm guessing the culprit is the "foreach" part, which iterates everything, even empty indexes. ... public void Draw(SpriteBatch spriteBatch, GameTime gameTime) { foreach (Tile tile in this.Tiles) { if (tile != null) { if (tile.Position.X < -this.Offset.X + 32) continue; if (tile.Position.X > -this.Offset.X + 1024 - 48) continue; if (tile.Position.Y < -this.Offset.Y + 32) continue; if (tile.Position.Y > -this.Offset.Y + 768 - 48) continue; tile.Draw(spriteBatch, gameTime); } } } ... Also here is the Tile.Draw method, which could also do with an update, as each Tile uses four calls to the SpriteBatch.Draw method. This is part of my autotiling system, which means drawing each corner depending on neighboring tiles. texture_* are Rectangles, are set once at level creation, not each update. ... public virtual void Draw(SpriteBatch spriteBatch, GameTime gameTime) { if (this.type == TileType.TileSet) { spriteBatch.Draw(this.texture, this.realm.Offset + this.Position, texture_tl, this.BlendColor); spriteBatch.Draw(this.texture, this.realm.Offset + this.Position + new Vector2(8, 0), texture_tr, this.BlendColor); spriteBatch.Draw(this.texture, this.realm.Offset + this.Position + new Vector2(0, 8), texture_bl, this.BlendColor); spriteBatch.Draw(this.texture, this.realm.Offset + this.Position + new Vector2(8, 8), texture_br, this.BlendColor); } } ... Any critique or suggestions to my code is welcome. Update: Solution added. Here's the final Level.Draw method. The Level.TileAt method simply checks the inputted values, to avoid OutOfRange exceptions. ... public void Draw(SpriteBatch spriteBatch, GameTime gameTime) { Int32 startx = (Int32)Math.Floor((-this.Offset.X - 32) / 16); Int32 endx = (Int32)Math.Ceiling((-this.Offset.X + 1024 + 32) / 16); Int32 starty = (Int32)Math.Floor((-this.Offset.Y - 32) / 16); Int32 endy = (Int32)Math.Ceiling((-this.Offset.Y + 768 + 32) / 16); for (Int32 x = startx; x < endx; x += 1) { for (Int32 y = starty; y < endy; y += 1) { Tile tile = this.TileAt(x, y); if (tile != null) tile.Draw(spriteBatch, gameTime); } } } ...

    Read the article

  • Obfuscation is not a panacea

    - by simonc
    So, you want to obfuscate your .NET application. My question to you is: Why? What are your aims when your obfuscate your application? To protect your IP & algorithms? Prevent crackers from breaking your licensing? Your boss says you need to? To give you a warm fuzzy feeling inside? Obfuscating code correctly can be tricky, it can break your app if applied incorrectly, it can cause problems down the line. Let me be clear - there are some very good reasons why you would want to obfuscate your .NET application. However, you shouldn't be obfuscating for the sake of obfuscating. Security through Obfuscation? Once your application has been installed on a user’s computer, you no longer control it. If they do not want to pay for your application, then nothing can stop them from cracking it, even if the time cost to them is much greater than the cost of actually paying for it. Some people will not pay for software, even if it takes them a month to crack a $30 app. And once it is cracked, there is nothing stopping them from putting the result up on the internet. There should be nothing suprising about this; there is no software protection available for general-purpose computers that cannot be cracked by a sufficiently determined attacker. Only by completely controlling the entire stack – software, hardware, and the internet connection, can you have even a chance to be uncrackable. And even then, someone somewhere will still have a go, and probably succeed. Even high-end cryptoprocessors have known vulnerabilities that can be exploited by someone with a scanning electron microscope and lots of free time. So, then, why use obfuscation? Well, the primary reason is to protect your IP. What obfuscation is very good at is hiding the overall structure of your program, so that it’s very hard to figure out what exactly the code is doing at any one time, what context it is running in, and how it fits in with the rest of the application; all of which you need to do to understand how the application operates. This is completely different to cracking an application, where you simply have to find a single toggle that determines whether the application is licensed or not, and flip it without the rest of the application noticing. However, again, there are limitations. An obfuscated application still has to run in the same way, and do the same thing, as the original unobfuscated application. This means that some of the protections applied to the obfuscated assembly have to be undone at runtime, else it would not run on the CLR and do the same thing. And, again, since we don’t control the environment the application is run on, there is nothing stopping a user from undoing those protections manually, and reversing some of the obfuscation. It’s a perpetual arms race, and it always will be. We have plenty of ideas lined about new protections, and the new protections added in SA 6.6 (method parent obfuscation and a new control flow obfuscation level) are specifically designed to be harder to reverse and reconstruct the original structure. So then, by all means, obfuscate your application if you want to protect the algorithms and what the application does. That’s what SmartAssembly is designed to do. But make sure you are clear what a .NET obfuscator can and cannot protect you against, and don’t expect your obfuscated application to be uncrackable. Someone, somewhere, will crack your application if they want to and they don’t have anything better to do with their time. The best we can do is dissuade the casual crackers and make it much more difficult for the serious ones. Cross posted from Simple Talk.

    Read the article

  • JEP 124: Enhance the Certificate Revocation-Checking API

    - by smullan
    Revocation checking is the mechanism to determine the revocation status of a certificate. If it is revoked, it is considered invalid and should not be used. Currently as of JDK 7, the PKIX implementation of java.security.cert.CertPathValidator  includes a revocation checking implementation that supports both OCSP and CRLs, the two main methods of checking revocation. However, there are very few options that allow you to configure the behavior. You can always implement your own revocation checker, but that's a lot of work. JEP 124 (Enhance the Certificate Revocation-Checking API) is one of the 11 new security features in JDK 8. This feature enhances the java.security.cert API to support various revocation settings such as best-effort checking, end-entity certificate checking, and mechanism-specific options and parameters. Let's describe each of these in more detail and show some examples. The features are provided through a new class named PKIXRevocationChecker. A PKIXRevocationChecker instance is returned by a PKIX CertPathValidator as follows: CertPathValidator cpv = CertPathValidator.getInstance("PKIX"); PKIXRevocationChecker prc = (PKIXRevocationChecker)cpv.getRevocationChecker(); You can now set various revocation options by calling different methods of the returned PKIXRevocationChecker object. For example, the best-effort option (called soft-fail) allows the revocation check to succeed if the status cannot be obtained due to a network connection failure or an overloaded server. It is enabled as follows: prc.setOptions(Enum.setOf(Option.SOFT_FAIL)); When the SOFT_FAIL option is specified, you can still obtain any exceptions that may have been thrown due to network issues. This can be useful if you want to log this information or treat it as a warning. You can obtain these exceptions by calling the getSoftFailExceptions method: List<CertPathValidatorException> exceptions = prc.getSoftFailExceptions(); Another new option called ONLY_END_ENTITY allows you to only check the revocation status of the end-entity certificate. This can improve performance, but you should be careful using this option, as the revocation status of CA certificates will not be checked. To set more than one option, simply specify them together, for example: prc.setOptions(Enum.setOf(Option.SOFT_FAIL, Option.ONLY_END_ENTITY)); By default, PKIXRevocationChecker will try to check the revocation status of a certificate using OCSP first, and then CRLs as a fallback. However, you can switch the order using the PREFER_CRLS option, or disable the fallback altogether using the NO_FALLBACK option. For example, here is how you would only use CRLs to check the revocation status: prc.setOptions(Enum.setOf(Option.PREFER_CRLS, Option.NO_FALLBACK)); There are also a number of other useful methods which allow you to specify various options such as the OCSP responder URI, the trusted OCSP responder certificate, and OCSP request extensions. However, one of the most useful features is the ability to specify a cached OCSP response with the setOCSPResponse method. This can be quite useful if the OCSPResponse has already been obtained, for example in a protocol that uses OCSP stapling. After you have set all of your preferred options, you must add the PKIXRevocationChecker to your PKIXParameters object as one of your custom CertPathCheckers before you validate the certificate chain, as follows: PKIXParameters params = new PKIXParameters(keystore); params.addCertPathChecker(prc); CertPathValidatorResult result = cpv.validate(path, params); Early access binaries of JDK 8 can be downloaded from http://jdk8.java.net/download.html

    Read the article

  • Introducing the Metro User Interface on Windows 2012

    - by andywe
    Although I am a big fan of using PowerShell to do many of my server operations, that aspect is well covered by those far more knowledgeable than I, and there is vast information around the web already on that. The new Metro interface, and getting around both Windows 8 and Windows Server 2012 though is relatively new, even for those whop ran the previews. What is this? A blank Desktop!   Where did the start button go? Well, it is still there...sort of. It is hidden, and acts like an auto hidden component that appear only when the mouse is hovered over the lower left corner of the screen. Those familiar with Gnome or OSX can relate this to the "Hot Corners" functions. To get to the start button, hover your mouse in the very left corner of the task bar. Let it sit there a moment, and a small blue square with colored tiles in it called start will appear. Click it. I clicked it and now I have all the tiles..What is this?   Welcome to the Metro interface. This is a much more modern look, and although at first seems weird and cumbersome, I have actually found that it is a bit more extensible, allowing greater organization and customization than the older explorer desktop. If you look closely, you'll see each box represents either a program, or program group. First, a few basics about using the start view. First and foremost, a right mouse click will bring up a bar on the bottom, with an icon towards the right. Notice it is titled “All Apps”. An even easier way in many places is to hover your mouse in the exact opposite corner, in the upper right. A sidebar will open and expose what used to be a widget bar (remember Vista?), and there are options for Search, Start, and Settings.   Ok Great, but where is everything? It’s all there…Click the All Apps icon.   Look better? Notice the scroll bar at the bottom. Move it right..your desktop is sized to your content..so you can have a smaller, or larger amount of programs exposed. Each icon can be secondary clicked (right mouse click for most of us, and an options bar at the bottom, rather than the old small context menu, is opened with some very familiar options.   Notice the top of the Windows Explorer window has some new features. You still have your right mouse click functions, but since the shortcuts for these items already exist..just copy them. There are many ways, but here is a long way to show you more of the interface. 1. Right mouse click a program icon, and select the Open File Location option. 2. Trusty file manager opens…but if you look closely up at top edge of the window, you’ll see a nifty enhancement. An orange colored box that is titled Shortcut Tools and another lavender box Title Application tools. Each of these adds options at the top of the file manager window to make selection easy. Of course, you can still secondary click an item in the listing window too. 3. Click shortcut tools, right click your app shortcut and copy it. Then simply paste it into the desktop outside the File Explorer window Also note some of the newer features. The large icons up top below the menu that has many common operations. The options change as you select each menu item. Well, that’s it for this installment. I hope this helps you out.

    Read the article

  • Pinterest and the Rising Power of Imagery

    - by Mike Stiles
    If images keep you glued to a screen, you’re hardly alone. Countless social users are letting their eyes do the walking, waiting for that special photo to grab their attention. And perhaps more than any other social network, Pinterest has been giving those eyes plenty of room to walk. Pinterest came along in 2010. Its play was that users could simply create topic boards and pin pictures to the appropriate boards for sharing. Yes there are some words, captions mostly, but not many. The speed of its growth raised eyebrows. Traffic quadrupled in the last quarter of 2011, with 7.51 million unique visitors in December alone. It now gets 1.9 billion monthly page views. And it was sticky. In the US, the average time a user spends strolling through boards and photos on Pinterest is 15 minutes, 50 seconds. Proving the concept of browsing a catalogue is not dead, it became a top 5 referrer for several apparel retailers like Land’s End, Nordstrom, and Bergdorfs. Now a survey of online shoppers by BizRate Insights says that Pinterest is responsible for more purchases online than Facebook. Over 70% of its users are going there specifically to keep up with trends and get shopping ideas. And when they buy, the average order value is $179. Pinterest is also scoring better in terms of user engagement. 66% of pinners regularly follow and repin retailers, whereas 17% of Facebook fans turn to that platform for purchase ideas. (Facebook still wins when it comes to reach and driving traffic to 3rd-party sites by the way). Social posting best practices have consistently shown that posts with photos are rewarded with higher engagement levels. You may be downright Shakespearean in your writing, but what makes images in the digital world so much more powerful than prose? 1. They transcend language barriers. 2. They’re fun and addictive to look at. 3. They can be consumed in fractions of a second, important considering how fast users move through their social content (admit it, you do too). 4. They’re efficient gateways. A good picture might get them to the headline. A good headline might then get them to the written content. 5. The audience for them surpasses demographic limitations. 6. They can effectively communicate and trigger an emotion. 7. With mobile use soaring, photos are created on those devices and easily consumed and shared on them. Pinterest’s iPad app hit #1 in the Apple store in 1 day. Even as far back as 2009, over 2.5 billion devices with cameras were on the streets generating in just 1 year, 10% of the number of photos taken…ever. But let’s say you’re not a retailer. What if you’re a B2B whose products or services aren’t visual? Should you worry about your presence on Pinterest? As with all things, you need a keen awareness of who your audience is, where they reside online, and what they want to do there. If it doesn’t make sense to put a tent stake in Pinterest, fine. But ignore the power of pictures at your own peril. If not visually, how are you going to attention-grab social users scrolling down their News Feeds at top speed? You’re competing with every other cool image out there from countless content sources. Bore us and we’ll fly right past you.

    Read the article

  • How to handle multi-processing of libraries which already spawn sub-processes?

    - by exhuma
    I am having some trouble coming up with a good solution to limit sub-processes in a script which uses a multi-processed library and the script itself is also multi-processed. Both, the library and script are modifiable by us. I believe the question is more about design than actual code, but for what it's worth, it's written in Python. The goal of the library is to hide implementation details of various internet routers. For that reason, the library has a "Proxy" factory method which takes the IP of a router as parameter. The factory then probes the device using a set of possible proxies. Usually, there is one proxy which immediately knows that is is able to send commands to this device. All others usually take some time to return (given a timeout). One thought was already to simply query the device for an identifier, and then select the proper proxy using that, but in order to do so, you would already need to know how to query the device. Abstracting this knowledge is one of the main purposes of the library, so that becomes a little bit of a "circular-requirement"/deadlock: To connect to a device, you need to know what proxy to use, and to know what proxy to create, you need to connect to a device. So probing the device is - as we can see - the best solution so far, apart from keeping a lookup-table somewhere. The library currently kills all remaining processes once a valid proxy has been found. And yes, there is always only one good proxy per device. Currently there are about 12 proxies. So if one create a proxy instance using the factory, 12 sub-processes are spawned. So far, this has been really useful and worked very well. But recently someone else wanted to use this library to "broadcast" a command to all devices. So he took the library, and wrote his own multi-processed script. This obviously spawned 12 * n processes where n is the number of IPs to which he broadcasted. This has given us two problems: The host on which the command was executed slowed down to a near halt. Aborting the script with CTRL+C ground the system to a total halt. Not even the hardware console responded anymore! This may be due to some Python strangeness which still needs to be investigated. Maybe related to http://bugs.python.org/issue8296 The big underlying question, is how to design a library which does multi-processing, so other applications which use this library and want to be multi-processed themselves do not run into system limitations. My first thought was to require a pool to be passed to the library, and execute all tasks in that pool. In that way, the person using the library has control over the usage of system resources. But my gut tells me that there must be a better solution. Disclaimer: My experience with multiprocessing is fairly limited. I have implemented a few straightforward which did not require access control to resources. So I have not yet any practical experience with semaphores or mutexes. p.s.: In the future, we may have enough information to do this without the probing. But the database which would contain the proper information is not yet operational. Also, the design about multiprocessing a multiprocessed library intrigues me :)

    Read the article

  • Editing files without race conditions?

    - by user2569445
    I have a CSV file that needs to be edited by multiple processes at the same time. My question is, how can I do this without introducing race conditions? It's easy to write to the end of the file without race conditions by open(2)ing it in "a" (O_APPEND) mode and simply write to it. Things get more difficult when removing lines from the file. The easiest solution is to read the file into memory, make changes to it, and overwrite it back to the file. If another process writes to it after it is in memory, however, that new data will be lost upon overwriting. To further complicate matters, my platform does not support POSIX record locks, checking for file existence is a race condition waiting to happen, rename(2) replaces the destination file if it exists instead of failing, and editing files in-place leaves empty bytes in it unless the remaining bytes are shifted towards the beginning of the file. My idea for removing a line is this (in pseudocode): filename = "/home/user/somefile"; file = open(filename, "r"); tmp = open(filename+".tmp", "ax") || die("could not create tmp file"); //"a" is O_APPEND, "x" is O_EXCL|O_CREAT while(write(tmp, read(file)); //copy the $file to $file+".new" close(file); //edit tmp file unlink(filename) || die("could not unlink file"); file = open(filename, "wx") || die("another process must have written to the file after we copied it."); //"w" is overwrite, "x" is force file creation while(write(file, read(tmp))); //copy ".tmp" back to the original file unlink(filename+".tmp") || die("could not unlink tmp file"); Or would I be better off with a simple lock file? Appender process: lock = open(filename+".lock", "wx") || die("could not lock file"); file = open(filename, "a"); write(file, "stuff"); close(file); close(lock); unlink(filename+".lock"); Editor process: lock = open(filename+".lock", "wx") || die("could not lock file"); file = open(filename, "rw"); while(contents += read(file)); //edit "contents" write(file, contents); close(file); close(lock); unlink(filename+".lock"); Both of these rely on an additional file that will be left over if a process terminates before unlinking it, causing other processes to refuse to write to the original file. In my opinion, these problems are brought on by the fact that the OS allows multiple writable file descriptors to be opened on the same file at the same time, instead of failing if a writable file descriptor is already open. It seems that O_CREAT|O_EXCL is the closest thing to a real solution for preventing filesystem race conditions, aside from POSIX record locks. Another possible solution is to separate the file into multiple files and directories, so that more granular control can be gained over components (lines, fields) of the file using O_CREAT|O_EXCL. For example, "file/$id/$field" would contain the value of column $field of the line $id. It wouldn't be a CSV file anymore, but it might just work. Yes, I know I should be using a database for this as databases are built to handle these types of problems, but the program is relatively simple and I was hoping to avoid the overhead. So, would any of these patterns work? Is there a better way? Any insight into these kinds of problems would be appreciated.

    Read the article

  • How to place rooms proceduraly (rule based) on in a game word

    - by gardian06
    I am trying to design the algorithm for my level generation which is a rule driven system. I have created all the rules for the system. I have taken care to insure that all rooms make sense in a grid type setup. for example: these rooms could make this configuration The logic flow code that I have so far Door{ Vector3 position; POD orient; // 5 possible values (up is not an option) bool Open; } Room{ String roomRule; Vector3 roomPos; Vector3 dimensions; POD roomOrient; // 4 possible values List doors<Door>; } LevelManager{ float scale = 18f; List usedRooms<Room>; List openDoors<Door> bool Grid[][][]; Room CreateRoom(String rule, Vector3 position, POD Orient){ place recieved values based on rule fill in other data } Vector3 getDimenstions(String rule){ return dimensions of the room } RotateRoom(POD rotateAmount){ rotate all items in the room } MoveRoom(Room toBeMoved, POD orientataion, float distance){ move the position of the room based on inputs } GenerateMap(Vector3 size, Vector3 start, Vector3 end){ Grid = array[size.y][size.x][size.z]; Room floatingRoom; floatingRoom = Room.CreateRoom(S01, start, rand(4)); usedRooms.Add(floatingRoom); for each Door in floatingRoom.doors{ openDoors.Add(door); } // fill used grid spaces floatingRoom = Room.CreateRoom(S02, end, rand(4); usedRooms.Add(floatingRoom); for each Door in floatingRoom.doors{ openDoors.Add(door); } Vector3 nRoomLocation; Door workingDoor; string workingRoom; // fill used grid spaces // pick random door on the openDoors list workingDoor = /*randomDoor*/ // get a random rule nRoomLocation = workingDoor.position; // then I'm lost } } I know that I have to make sure for convergence (namely the end is reachable), and to do this until there are no more doors on the openDoors list. right now I am simply trying to get this to work in 2D (there are rules that introduce 3D), but I am working on a presumption that a rigorous algorithm can be trivially extended to 3D. EDIT: my thought pattern so far is to take an existing open door and then pick a random room (restrictions can be put in later) place that room's center at the doors location move the room in the direction of the doors orientation half the rooms dimension w/respect to that axis then test against the 3D array to see if all the grid points are open, or have been used, or if there is even space to put the room (caseEdge) if caseEdge (which can also occur in between rooms) then put the door on a toBeClosed list, and remove it from the open list (placing a wall or something there). then to do some kind of test that both the start, and the goal are connected, and reachable from each other (each room has nodes for AI, but I don't want to "have" to pull those out to accomplish this). but this logic has the problem for say the U, or L shaped rooms in my example, and then I also have a problem conceptually if the room needs to be rotated.

    Read the article

  • Upgrade to Xubuntu 13.10 - Saucy Salamander

    As a common 'fashion' it is possible to upgrade an existing installation of Ubuntu or one of its derivates every six months. Of course, you might opt-in for the adventure and directly keep your system always on the latest version (including alphas and betas), or you might like to play safe and stay on the long-term support (LTS) versions which are updated every two years only. As for me, I'd like to jump from release to release on my main desktop machine. And since 17th October Saucy Salamander or also known as Ubuntu 13.10 has been released for general use. The following paragraphs document the steps I went in order to upgrade my system to the recent version. Don't worry about the fact that I'm actually using Xubuntu. It's mainly a flavoured version of Ubuntu running Xfce 4.10 as default X Window manager. Well, I have Gnome and LXDE on the same system... just out of couriosity. Preparing the system Before you think about upgrading you have to ensure that your current system is running on the latest packages. This can be done easily via a terminal like so: $ sudo apt-get update && sudo apt-get -y dist-upgrade --fix-missing Next, we are going to initiate the upgrade itself: $ sudo update-manager As a result the graphical Software Updater should inform you that a newer version of Ubuntu is available for installation. Ubuntu's Software Updater informs you whether an upgrade is available Running the upgrade After clicking 'Upgrade...' you will be presented with information about the new version. Details about Ubuntu 13.10 (Saucy Salamander) Simply continue with the procedure and your system will be analysed for the next steps. Analysing the existing system and preparing the actual upgrade to 13.10 Next, we are at the point of no return. Last confirmation dialog before having a coffee break while your machine is occupied to download the necessary packages. Not the best bandwidth at hand after all... yours might be faster. Are you really sure that you want to start the upgrade? Let's go and have fun! Anyway, bye bye Raring Ringtail and Welcome Saucy Salamander! In case that you added any additional repositories like Medibuntu or PPAs you will be informed that they are going to be disabled during the upgrade and they might require some manual intervention after completion. Ubuntu is playing safe and third party repositories are disabled during the upgrade Well, depending on your internet bandwidth this might take something between a couple of minutes and some hours to download all the packages and then trigger the actual installation process. In my case I left my PC unattended during the night. Time to reboot Finally, it's time to restart your system and see what's going to happen... In my case absolutely nothing unexpected. The system booted the new kernel 3.11.0 as usual and I was greeted by a new login screen. Honestly, 'same' system as before - which is good and I love that fact of consistency - and I can continue to work productively. And also Software Updater confirms that we just had a painless upgrade: System is running Ubuntu 13.10 - Saucy Salamander - and up to date See you in six months again... ;-) Post-scriptum In case that you would to upgrade to the latest development version of Ubuntu, run the following command in a console: $ sudo update-manager -d And repeat all steps as described above.

    Read the article

  • Selective Suppression of Log Messages

    - by Duncan Mills
    Those of you who regularly read this blog will probably have noticed that I have a strange predilection for logging related topics, so why break this habit I ask?  Anyway here's an issue which came up recently that I thought was a good one to mention in a brief post.  The scenario really applies to production applications where you are seeing entries in the log files which are harmless, you know why they are there and are happy to ignore them, but at the same time you either can't or don't want to risk changing the deployed code to "fix" it to remove the underlying cause. (I'm not judging here). The good news is that the logging mechanism provides a filtering capability which can be applied to a particular logger to selectively "let a message through" or suppress it. This is the technique outlined below. First Create Your Filter  You create a logging filter by implementing the java.util.logging.Filter interface. This is a very simple interface and basically defines one method isLoggable() which simply has to return a boolean value. A return of false will suppress that particular log message and not pass it onto the handler. The method is passed the log record of type java.util.logging.LogRecord which provides you with access to everything you need to decide if you want to let this log message pass through or not, for example  getLoggerName(), getMessage() and so on. So an example implementation might look like this if we wanted to filter out all the log messages that start with the string "DEBUG" when the logging level is not set to FINEST:  public class MyLoggingFilter implements Filter {     public boolean isLoggable(LogRecord record) {         if ( !record.getLevel().equals(Level.FINEST) && record.getMessage().startsWith("DEBUG")){          return false;            }         return true;     } } Deploying   This code needs to be put into a JAR and added to your WebLogic classpath.  It's too late to load it as part of an application, so instead you need to put the JAR file into the WebLogic classpath using a mechanism such as the PRE_CLASSPATH setting in your domain setDomainEnv script. Then restart WLS of course. Using The final piece if to actually assign the filter.  The simplest way to do this is to add the filter attribute to the logger definition in the logging.xml file. For example, you may choose to define a logger for a specific class that is raising these messages and only apply the filter in that case.  <logger name="some.vendor.adf.ClassICantChange"         filter="oracle.demo.MyLoggingFilter"/> You can also apply the filter using WLST if you want a more script-y solution.

    Read the article

  • Is the Leptonica implementation of 'Modified Median Cut' not using the median at all?

    - by TheCodeJunkie
    I'm playing around a bit with image processing and decided to read up on how color quantization worked and after a bit of reading I found the Modified Median Cut Quantization algorithm. I've been reading the code of the C implementation in Leptonica library and came across something I thought was a bit odd. Now I want to stress that I am far from an expert in this area, not am I a math-head, so I am predicting that this all comes down to me not understanding all of it and not that the implementation of the algorithm is wrong at all. The algorithm states that the vbox should be split along the lagest axis and that it should be split using the following logic The largest axis is divided by locating the bin with the median pixel (by population), selecting the longer side, and dividing in the center of that side. We could have simply put the bin with the median pixel in the shorter side, but in the early stages of subdivision, this tends to put low density clusters (that are not considered in the subdivision) in the same vbox as part of a high density cluster that will outvote it in median vbox color, even with future median-based subdivisions. The algorithm used here is particularly important in early subdivisions, and 3is useful for giving visible but low population color clusters their own vbox. This has little effect on the subdivision of high density clusters, which ultimately will have roughly equal population in their vboxes. For the sake of the argument, let's assume that we have a vbox that we are in the process of splitting and that the red axis is the largest. In the Leptonica algorithm, on line 01297, the code appears to do the following Iterate over all the possible green and blue variations of the red color For each iteration it adds to the total number of pixels (population) it's found along the red axis For each red color it sum up the population of the current red and the previous ones, thus storing an accumulated value, for each red note: when I say 'red' I mean each point along the axis that is covered by the iteration, the actual color may not be red but contains a certain amount of red So for the sake of illustration, assume we have 9 "bins" along the red axis and that they have the following populations 4 8 20 16 1 9 12 8 8 After the iteration of all red bins, the partialsum array will contain the following count for the bins mentioned above 4 12 32 48 49 58 70 78 86 And total would have a value of 86 Once that's done it's time to perform the actual median cut and for the red axis this is performed on line 01346 It iterates over bins and check they accumulated sum. And here's the part that throws me of from the description of the algorithm. It looks for the first bin that has a value that is greater than total/2 Wouldn't total/2 mean that it is looking for a bin that has a value that is greater than the average value and not the median ? The median for the above bins would be 49 The use of 43 or 49 could potentially have a huge impact on how the boxes are split, even though the algorithm then proceeds by moving to the center of the larger side of where the matched value was.. Another thing that puzzles me a bit is that the paper specified that the bin with the median value should be located, but does not mention how to proceed if there are an even number of bins.. the median would be the result of (a+b)/2 and it's not guaranteed that any of the bins contains that population count. So this is what makes me thing that there are some approximations going on that are negligible because of how the split actually takes part at the center of the larger side of the selected bin. Sorry if it got a bit long winded, but I wanted to be as thoroughas I could because it's been driving me nuts for a couple of days now ;)

    Read the article

  • Is hidden content (display: none;) -indexed- by search engines? [closed]

    - by user568458
    Possible Duplicate: How bad is it to use display: none in CSS? We've established on this site before (in this question) that, since there are so many legitimate uses for hiding content with display: none; when creating interactive features, that sites aren't automatically penalised for content that is hidden this way (so long as it doesn't look algorithmically spammy). Google's Webmaster guidelines also make clear that a good practice when using content that is initially legitimately hidden for interactivity purposes is to also include the same content in a <noscript> tag, and Google recommend that if you design and code for users including users with screen readers or javascript disabled, then 9 times out of 10 good relevant search rankings will follow (though their specific advice seems more written for cases where javascript writes new content to the page). JavaScript: Place the same content from the JavaScript in a tag. If you use this method, ensure the contents are exactly the same as what’s contained in the JavaScript, and that this content is shown to visitors who do not have JavaScript enabled in their browser. So, best practice seems pretty clear. What I can't find out is, however, the simple factual matter of whether hidden content is indexed by search engines (but with potential penalties if it looks 'spammy'), or, whether it is ignored, or, whether it is indexed but with a lower weighting (like <noscript> content is, apparently). (for bonus points it would be great to know if this varies or is consistent between display: none;, visibility: hidden;, etc, but that isn't crucial). This is different to the other questions on display:none; and SEO - those are about good and bad practice and the answers are discussions of good and bad practice, I'm interested simply in the factual 'Yes or no' question of whether search engines index, or ignore, content that is in display: none; - something those other questions' answers aren't totally clear on. One other question has an answer, "Yes", supported by a link to an article that doesn't really clear things up: it establishes that search engines can spot that text is hidden, it discusses (again) whether hidden text causes sites to be marked as spam, and ultimately concludes that in mid 2011, Google's policy on hidden text was evolving, and that they hadn't at that time started automatically penalising display:none; or marking it as spam. It's clear that display: none; isn't always spam and isn't always treated as spam (many Google sites use it...): but this doesn't clear up how, or if, it is indexed. What I will do will be to follow the guidelines and make sure that all the content that is initially hidden which regular users can explore using javascript-driven interactivity is also structured in way that noscript/screenreader users can use. So I'm not interested in best practice, opinions etc because best practice seems to be really clear: accessibility best practices boosts SEO. But I'd like to know what exactly will happen: whether any display: none; content I have alongside <noscript> or otherwise accessibility-optimised content will be be ignored, or indexed again, or picked up to compare against the <noscript> content but not indexed... etc.

    Read the article

  • Entity System with C++ templates

    - by tommaisey
    I've been getting interested in the Entity/Component style of game programming, and I've come up with a design in C++ which I'd like a critique of. I decided to go with a fairly pure Entity system, where entities are simply an ID number. Components are stored in a series of vectors - one for each Component type. However, I didn't want to have to add boilerplate code for every new Component type I added to the game. Nor did I want to use macros to do this, which frankly scare me. So I've come up with a system based on templates and type hinting. But there are some potential issues I'd like to check before I spend ages writing this (I'm a slow coder!) All Components derive from a Component base class. This base class has a protected constructor, that takes a string parameter. When you write a new derived Component class, you must initialise the base with the name of your new class in a string. When you first instantiate a new DerivedComponent, it adds the string to a static hashmap inside Component mapped to a unique integer id. When you subsequently instantiate more Components of the same type, no action is taken. The result (I think) should be a static hashmap with the name of each class derived from Component that you instantiate at least once, mapped to a unique id, which can by obtained with the static method Component::getTypeId ("DerivedComponent"). Phew. The next important part is TypedComponentList<typename PropertyType>. This is basically just a wrapper to an std::vector<typename PropertyType> with some useful methods. It also contains a hashmap of entity ID numbers to slots in the array so we can find Components by their entity owner. Crucially TypedComponentList<> is derived from the non-template class ComponentList. This allows me to maintain a list of pointers to ComponentList in my main ComponentManager, which actually point to TypedComponentLists with different template parameters (sneaky). The Component manager has template functions such as: template <typename ComponentType> void addProperty (ComponentType& component, int componentTypeId, int entityId) and: template <typename ComponentType> TypedComponentList<ComponentType>* getComponentList (int componentTypeId) which deal with casting from ComponentList to the correct TypedComponentList for you. So to get a list of a particular type of Component you call: TypedComponentList<MyComponent>* list = componentManager.getComponentList<MyComponent> (Component::getTypeId("MyComponent")); Which I'll admit looks pretty ugly. Bad points of the design: If a user of the code writes a new Component class but supplies the wrong string to the base constructor, the whole system will fail. Each time a new Component is instantiated, we must check a hashed string to see if that component type has bee instantiated before. Will probably generate a lot of assembly because of the extensive use of templates. I don't know how well the compiler will be able to minimise this. You could consider the whole system a bit complex - perhaps premature optimisation? But I want to use this code again and again, so I want it to be performant. Good points of the design: Components are stored in typed vectors but they can also be found by using their entity owner id as a hash. This means we can iterate them fast, and minimise cache misses, but also skip straight to the component we need if necessary. We can freely add Components of different types to the system without having to add and manage new Component vectors by hand. What do you think? Do the good points outweigh the bad?

    Read the article

  • Upgrading to 9.2 - Info You Can Use (part 1)

    - by John Webb
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Rebekah Jackson joins our blog with a series of helpful hints on planning your upgrade to PeopleSoft 9.2.   Find Features & Capabilities There are many ways that you might learn about new features and capabilities within our releases, but if you aren’t sure where to start or how best to go about it, we recommend: Go to www.peoplesoftinfo.com Select the product line you are interested in, and go to the ‘Release Content’ tab Use the Video Feature Overviews (VFOs) on YouTube and the Cumulative Feature Overview (CFO) tool to find features and functions. The VFOs are brief recordings that summarize some of our most popular capabilities. These recordings are great tools for learning about new features, or helping others to visualize the value they can bring to your organization. The VFOs focus on some of our highest value and most compelling new capabilities. We also provide summarized ‘Why Upgrade to 9.2’ VFOs for HCM, Financials, and Supply Chain. The CFO is a spreadsheet based tool that allows you to select the release you are currently on, and compare it to the new release. It will return the list of all new features and capabilities, by product. You can browse the full list and / or highlight areas that look particularly interesting. Once you have a list of features by product, use the Release Value Proposition, Pre-Release Notes, and the Release Notes documents to get more details on and supporting value statements about why those features will be helpful. Gather additional data and supporting information, including: Go to the Product Data Sheets tab, and review the respective data sheets. These summarize the capabilities in the product, and provide succinct value statements for the product and capabilities. The PeopleSoft 9.2 Upgrade page, which has many helpful resources. Important Notes:   -  We recommend that you go through the above steps for the application areas of interest, as well as for PeopleTools. There are many areas in PeopleTools 8.53 and the 9.2 application releases that combine technical and functional capabilities to deliver transformative value.    - We also recommend that you review the Portal Solutions content. With your license to PeopleSoft applications, you have access to many of the most powerful capabilities within the Interaction Hub.    -  If you have recently upgraded to PeopleSoft 9.1, and an immediate upgrade to 9.2 is simply not realistic, you can apply the same approaches described here to find untapped capabilities in your current products. Many of the features in 9.2 were delivered first in our 9.1 Feature Packs. To find the Release Value Proposition, Pre-Release Notes, and Release Notes for these releases, search on ‘PeopleSoft 9.1 Documentation Home Page’ on My Oracle Support, and select your desired product area. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";}

    Read the article

  • Using 3rd Party JavaScript Plugins Hardwired With &lsquo;document.write&rsquo;

    - by ToStringTheory
    Introduction Have you ever had the need to implement a 3rd party JavaScript plugin, but your needs didn’t fit the model and usage defined by the API or documentation of the plugin?  Recently I ran into this issue when I was trying to implement a web snapshot plugin into our site.  To use their plugin, you had to include a script tag to the plugin on their server with an API key.  The second part of the usage was to include a <script> tag around a function call wherever you wanted a snapshot to appear. The Problem When trying to use the service, the images did not display.  I checked a couple of things and didn’t find anything wrong at first..  It wasn’t until I looked at the function that was called by the inline script did I find the issue – a call to the webservice, followed by a call to ‘document.write’ in its callback.  The solution in which I was trying to implement the plugin happened to be in response to an AJAX call after the document had completely loaded.  After the page has loaded, document.write does nothing. My first thought for a solution was to just cache the script from the service, and edit it do something like a return function or callback that I could use to edit the document from.  However, I quickly discovered that there is no way to cache the script from the service, as it had a hash in the function where it would call the server.  The hash was updated every few seconds/minutes, expiring old hashes.  This meant that I wouldn’t be able to edit the script and upload a new version to my server, as the script would not work after a few minutes from originally getting the script from the service. Solution The solution eluded me until I realized that this was JavaScript I was dealing with.  A language designed so that you could do just about anything to any library, function, or object…  At this point, the solution was simple – take control of the document.write function.  Using a buffer variable, and a simple function call, it is eerily simple to perform: //what would have been output to the document var buffer = ""; //store a reference to the real document.write var dw = document.write; //redefine document.write to store to our buffer document.write = function (str) {buffer += str;} //execute the function containing calls to document.write eval('{function encapsulated in <script></script> tags}'); //restore the original document.write function (just in case) document.write = dw; That’s it.  Instead of using the script tags where I wanted to include a snapshot, I called a function passing in the URL to the page I wanted a snapshot of.  After that last line of code, what would have been output to the document (or not in the case of the ajax call) was instead stored in buffer. Conclusion While the solution itself is simple, coming from a background much more footed in the .Net platform, I believe that this is a prime example of always keeping the language that you are working in in mind.  While this may seem obvious at first, as I KNEW I was in JavaScript, I never thought of taking control of the document.write function because I am more accustomed to the .Net world.  I can’t simply replace the functionality of Console.WriteLine.

    Read the article

  • How to introduce a computer illiterate 50-year old to programming [closed]

    - by sunday
    The other day my dad asked me a question that I would have never expected from him. "How can I learn C++?" My dad is turning 56 this year and computers are a distant concept for him. He doesn't know how to use a phone very well besides calling numbers (no speed dial or contacts); though he has started to learn computers a little better - to the point that he knows how to open the internet (in Windows) and browse around (and has successfully completed several job applications entirely on his own online, of which he was offered positions too). But still, these are too narrow-windowed experiences to mean much, really. While he may not have the background, my dad knows how to read. And I mean reading as a skill, not just an ability. He has little to no college education (financial problems, family, etc.) and was fortunate enough to finish high school, but still taught himself to become a master electrician and has been one for almost 30 years now. He did the same with guitar, learning to play at a very professional level and has been praised for his skill. In high school, he picked up a weight lifting book - and was the only person in his high school at the time to qualify officially as an "athlete" by national standards. In all cases, he just needed something to read. Something to teach him. He absorbs information like a sponge. I have no doubt in my dad's motivation or capability of doing this, so my general goal is simply: Get my dad into the world of computers, and get him on the road to programming. I strongly believe that once I get him through the fundamentals, his drive and reading skill will keep him going on this own. So I'm asking you all: where should I start with all this? And what are the best resources out there? Should I get him to start Linux instead of Windows? Is C++ a bad idea? Remember, he needs to (IMO) learn computers first, and then get that first grasp (the "Hello world" experience) of programming. For money's sake and at top preference, I'd like free online resources that he can read, but by all means any good suggestions in print or paid-for-online are welcome (that I could possibly look into later to purchase). And also, I intend to start him off with C++ (no Python, Java, etc.), because I know it the best and will be able to help him along the way with code. (I have minimal knowledge right now in other languages). Edit: I'm getting a lot of persistent suggestions to use Python. The only reason I wanted to do C++ is that I KNOW it and can be THERE when my dad needs help. My VERY FIRST exposure to programming ever was Java. I learned Java, and I got good at it. I open to other suggestions, but please provide an effective application of your suggestions. EDIT #2: I understand my approach/thinking/knowledge could be lacking here. I'm a sophomore level undergraduate CS major. If you don't agree with anything in my post, tell me why - give me ideas, information - that's why I'm asking in the first place. To narrow down my general goal to specific reachable goals.

    Read the article

  • Changing the Operating System with only Ubuntu installed

    - by Games Brainiac
    I really wanted to dive into the world of Open Source operating systems, so I downloaded the latest version of Ubuntu (13.10), and installed it on a clean(no operating system installed, absolutely nothing) Lenovo ThinkPad machine. After a few days, I wanted to try out a different Operating System (Elementary OS). I downloaded the ISO file, burned it to a USB, tested that the USB booted from a different computer (I have 2, one is the Lenovo, the other a HP). I was able to get the bootscreen, and everything worked like a charm after I set the BIOS to boot from USB Disk Drive instead of HD. After this, I went back to Lenovo, and tried to open up the boot menu, by pressing F12, so that I could load from a temporary device. To my surprise, nothing but the HD was listed. There was no Optical Drive, No USB Drive, absolutely nothing. So, I thought that these devices were probably disabled. So I went into my BIOS and checked to see what was the case. I saw that all my devices were enabled. USB and all the other devices such as network cable and the rest were all enabled. So, I thought this probably had something to do wit UEFI and Legacy Boot options. So, I made sure that both were enabled. This did not solve the problem either. Again, I got nothing but the option to boot from my Hard Disk. I thought the USB had to be at fault. I tried different ports, but to no avail. Next, I tried with a Live CD, which had Ubuntu on it. This failed too. I simply could not boot from anything other than my hard disk. Okay, so at this point, I was pretty desperate, so I installed Boot-Repair through: sudo add-apt-repository ppa:yannubuntu/boot-repair sudo apt-get update sudo apt-get install boot-repair What this did is lead me to GRUB. Ideally, its just a screen that gives me the option to load from Ubuntu or Advanced Settings. The Advanced settings had nothing but Ubuntu options in it. So, I kept on pressing ESC and that led me to the the grub console, and thats where I am right now with my Lenovo. I've also tried updating the BIOS, but Lenovo only has packages for Red Hat and Windows. So, a dead end there too. Right now, I need to know if there is any way that I can just delete everything from my Lenovo? I want to revert it back to its blank factory condition. How can I achieve this? I have tried to elaborate my problem as best I could. If there is any important information that I've missed out, please do not hesitate to leave a comment. I would have included some screen shots, but BIOS screen shots are a little hard to manage. However, I can provide a camera Image of the boot screen if needed (doing that as we speak).

    Read the article

  • Rethinking Oracle Optimizer Statistics for P6 Part 2

    - by Brian Diehl
    In the previous post (Part 1), I tried to draw some key insights about the relationship between P6 and Oracle Optimizer Statistics.  The first is that average cardinality has the greatest impact on query optimization and that the particular queries generated by P6 are more likely to use this average during calculations. The second is that these are statistics that are unlikely to change greatly over the life of the application. Ultimately, our goal is to get the best query optimization possible.  Or is it? Stability No application administrator wants to get the call at 9am that their application users cannot get there work done because everything is running slow. This is a possibility with a regularly scheduled nightly collection of statistics. It may not just be slow performance, but a complete loss of service because one or more queries are optimized poorly. Ideally, this should not be the case. The database optimizer should make better decisions with more up-to-date data. Better statistics may give incremental performance benefit. However, this benefit must be balanced against the potential cost of system down time.  It is stability that we ultimately desire and not absolute optimal performance. We do want the benefit from more accurate statistics and better query plans, but not at the risk of an unusable system. As a result, I've developed the following methodology around managing database statistics for the P6 database.  1. No Automatic Re-Gathering - The daily, weekly, or other interval of statistic gathering is unlikely to be beneficial. Quite the opposite. It is more likely to cause problems. 2. Smart Re-Gathering - The time to collect statistics is when things have changed significantly. For a new installation of P6, this is happening more often because the data is growing from a few rows to thousands and more. But for a mature system, the data is not changing significantly from week-to-week. There are times to collect statistics: New releases of the application Changes in the underlying hardware or software versions (ex. new Oracle RDBMS version) When additional user groups are added. The new groups may use the software in significantly different ways. After significant changes in the data. This may be monthly, quarterly or yearly.  3. Always Test - If you take away one thing from this post, it would be to always have a plan to test after changing statistics. In reality, statistics can be collected as often as you desire provided there are tests in place to verify that performance is the same or better. These might be automated tests or simply a manual script of application functions. 4. Have a Way Out - Never change the statistics without a way to return to the previous set. Think of the statistics as one part of the overall application code that also includes the source code--both application and RDBMS. It would be foolish to change to the new code without a way to get back to the previous version. In the final post, I will talk about the actual script I created for P6 PMDB and possible future direction for managing query performance. 

    Read the article

  • How do you go from a so so programmer to a great one? [closed]

    - by Cervo
    How do you go from being an okay programmer to being able to write maintainable clean code? For example David Hansson was writing Basecamp when in the process he created Rails as part of writing Basecamp in a clean/maintainable way. But how do you know when there is value in a side project like that? I have a bachelors in computer science, and I am about to get a masters and I will say that colleges teach you to write code to solve problems, not neatly or anything. Basically you think of a problem, come up with a solution, and write it down...not necessarily the most maintainable way in the world. Also my first job was in a startup, and now my third is in a small team in a large company where the attitude was/is get it done yesterday (also most of my jobs are mainly database development with SQL with a few ASP.NET web pages/.NET apps on the side). So of course cut/paste is more favored than making things more cleanly. And they would rather have something yesterday even if you have to rewrite it next month rather than to have something in a week that lasts for a year. Also spaghetti code turns up all over the place, and it takes very smart people to write/understand/maintain spaghetti code...However it would be better to do things so simple/clean that even a caveman/woman could do maintenance. Also I get very bored/unmotivated having to go modify the same things cut/pasted in a few locations. Is this the type of skill that you need to learn by working with a serious software organization that has an emphasis on maintenance and maybe even an architect who designs a system architecture and reviews code? Could you really learn it by volunteering on an open source project (it seems to me that a full time programmer job is way more practice than a few hours a week on an open source project)? Is there some course where you can learn this? I can attest that graduate school and undergraduate school do not really emphasize clean software at all. They just teach the structures/algorithms and then send you off into the world to solve problems. Overall I think the first thing is learning to write clean/maintainable code within the bounds of the project in order to become a good programmer. Then the next thing is learning when you need to do a side project (like a framework) to make things more maintainable/clean even while you still deliver things for the deadline in order to become a great programmer. For example, you are making an SQL report and someone gives you 100 calculations for individual columns. At what point does it make sense to construct a domain specific language to encode the rules in simply and then generate all the SQL as opposed to cut/pasting the query from the table a bunch of times and then adjusting each query to do the appropriate calculations. This is the type of thing I would say a great programmer would know. He/she would maybe even know ways to avoid the domain specific language and to still do all the calculations without creating an unmaintainable mess or a ton of repetitive code to cut/paste everywhere.

    Read the article

  • Making user input/math on data fast, unlike excel type programs

    - by proGrammar
    I'm creating a research platform solely for myself to do some research on data. Programs like excel are terribly slow for me so I'm trying to come up with another solution. Originally I used excel. A1 was the cell that contained the data and all other cells in use calculated something on A1, or on other cells, that all could be in the end traced to A1. A1 was like an element of an array, I then I incremented it to go through all my data. This was way too slow. So the only other option I found originally was to hand code in c# the calculations inside a loop. Then I simply recompiled each time I changed my math. This was terribly slow to do and I had to order everything correctly so things would update correctly (dependencies). I could have also used events, but hand coding events for each cell like calculation would also be very slow. Next I created an application to read Excel and to perfectly imitate it. Which is what I now use. Basically I write formulas onto a fraction of my data to get live results inside excel. Then my program reads excel, writes another c# program, compiles it, and runs that program which runs my excel created formulas through a lot more data a whole lot faster. The advantage being my application dependency sorts everything (or I could use events) so I don't have to (like excel does) And of course the speed. But now its not a single application anymore. Instead its 2 applications, one which only reads my formulas and writes another program. The other one being the result which only lives for a short while before I do other runs through my data with different formulas / settings. So I can't see multiple results at one time without introducing even more programs like a database or at least having the 2 applications talking to each other. My idea was to have a dll that would be written, compiled, loaded, and unloaded again and again. So a self-updating program, sort of. But apparently that's not possible without another appdomain which means data has to be marshaled to be moved between the appdomains. Which would slow things down, not for summaries, but for other stuff I need to do with all my data. I'm also forgetting to mention a huge problem with restarting an application again and again which is having to reload ALL my data into memory again and again. But its still a whole lot faster than excel. I'm really super puzzled as to what people do when they want to research data fast. I'm completely unable to have a program accept user input and having it fast. My understanding is that it would have to do things like excel which is to evaluate strings again and again. So my only option is to repeatedly compile applications. Do I have a correct understanding on computer science? I've only just began programming, and didn't think I would have to learn much to do some simple math on data. My understanding is its either compiling my user defined stuff to a program or evaluating them from a string or something stupid again and again. And my only option is to probably switch operating systems or something to be able to have a program compile and run itself without stopping (writing/compiling dll, loading dll to program, unloading, and repeating). Can someone give me some idea on how computers work? Is anything better possible? Like a running program, that can accept user input and compile it and then unload it later? I mean heck operating systems dont need to be RESTARTED with every change to user input. What is this the cave man days? Sorry, it's just so super frustrating not knowing what one can do, and can't do. If only I could understand and learn this stuff fast enough.

    Read the article

  • Disabling the right-click sub menu using JQuery

    - by nikolaosk
    Recently I needed to disable the right-click contextual menu in an HTML page for a very simple HTML application I was creating for a friend.This is going to be a short post where I will demonstrate how to disable the right-click contextual menu.I will use the very popular JQuery Library. Please download the library (minified version) from http://jquery.com/downloadPlease find here all my posts regarding JQuery.In this hands-on example I will be using Expression Web 4.0.This application is not a free application. You can use any HTML editor you like.You can use Visual Studio 2012 Express edition. You can download it here. I am going to create a very simple HTML 5 page with some text and an image. The HTML markup for the page follows. <!DOCTYPE html><html lang="en">  <head>    <title>HTML 5, CSS3 and JQuery</title>        <meta http-equiv="Content-Type" content="text/html;charset=utf-8" >    <link rel="stylesheet" type="text/css" href="style.css">     <script type="text/javascript" src="jquery-1.8.2.min.js">        </script><script type="text/javascript"> (function ($) { $(document).bind('contextmenu', function () { return false;}); })(jQuery); </script>       </head>  <body>      <div id="header">      <h1>Learn cutting edge technologies</h1>      <h2>HTML 5, JQuery, CSS3</h2>    </div>      <figure>  <img src="html5.png" alt="HTML 5"></figure>        <div id="main">          <h2>HTML 5</h2>                        <article>          <p>            HTML5 is the latest version of HTML and XHTML. The HTML standard defines a single language that can be written in HTML and XML. It attempts to solve issues found in previous iterations of HTML and addresses the needs of Web Applications, an area previously not adequately covered by HTML.          </p>          </article>      </div>             </body>  </html> This is the JQuery code, I use (function ($) { $(document).bind('contextmenu', function () { return false;}); })(jQuery); I simply disable/cancel the contextmenu event.When I load the simple page on the browser and I right-click the context menu does not appear.Hope it helps!!!

    Read the article

  • nginx php5-fpm "File not found" -- FastCGI sent in stderr: "Primary script unknown"

    - by jmfayard
    so I'm trying to run for the first time the nginx web server with php5-fpm on a debian wheezy server Hitting a php file display simply File not found I have done my research (waste a lot of hours actually ;), there are a lot of people that have similar problems, yet I didn't succeed to correct it with what worked for them. I still have the same error : $ tail /var/log/nginx/access.log /var/log/nginx/error.log /var/log/php5-fpm.log | less == /var/log/nginx/error.log <== 2013/10/26 21:36:00 [error] 6900#0: *1971 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, I have tried a lot of things, it's hard to remember what. I have put my config files on github my /etc/nginx/nginx.conf my /etc/php5/fpm/php-fpm.conf Currently, the nginx.conf configuration uses this... server { server_name mydomain.tld; root /srv/data1/test; location ~ \.php$ { try_files $uri =404; fastcgi_pass 127.0.0.1:9000; fastcgi_index index.php; fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; include fastcgi_params; } } /etc/php5/fpm/pool.d/www.conf contains listen = 127.0.0.1:9000 I have tried the unix socket version, same thing. fastcgi_pass unix:/var/run/php5-fpm.sock; I made sure the server is started $ netstat -alnp | grep LISTEN tcp 0 0 127.0.0.1:9000 0.0.0.0:* LISTEN 6913/php-fpm.conf) tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 4785/mysqld tcp 0 0 0.0.0.0:842 0.0.0.0:* LISTEN 2286/inetd tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN 2812/rpcbind tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 5710/nginx tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 2560/sshd tcp 0 0 0.0.0.0:443 0.0.0.0:* LISTEN 5710/nginx tcp6 0 0 :::111 :::* LISTEN 2812/rpcbind unix 2 [ ACC ] STREAM LISTENING 323648 6574/tmux /tmp//tmux-1000/default unix 2 [ ACC ] STREAM LISTENING 619072 6790/fcgiwrap /var/run/fcgiwrap.socket unix 2 [ ACC ] SEQPACKET LISTENING 323 464/udevd /run/udev/control unix 2 [ ACC ] STREAM LISTENING 610686 2812/rpcbind /var/run/rpcbind.sock unix 2 [ ACC ] STREAM LISTENING 318633 4785/mysqld /var/run/mysqld/mysqld.sock Each time I modify the nginx.conf file, I make sure to relaunch this command nginx -t && nginx -s reload && echo "nginx configuration reloaded" and same thing for php5-fpm /etc/init.d/php5-fpm restart Thanks for your help :-)

    Read the article

  • Windows Server 2012 Branchcache vs. DFS-R

    - by TheCleaner
    Warning, subjective question ahead! But hopefully a good one that won't get closed. SCENARIO: I have a branch office that currently has no on-premise server. They access everything including a DC across a 12Mbps WAN link (MPLS). The link isn't saturated, averaging around 20% utilization. The circuit is very stable and has a high SLA and excellent uptime. However, large file transfers (mainly reads, not writes) from the file server across the WAN can be slow. We don't currently utilize DFS. RESEARCH DONE: I'm aware of WAN acceleration, using either dedicated hardware (Riverbed) or a dedicated software VM (Silver Peak) for example. But the pricing is outside of our current budget and the need isn't quite there yet from our perspective (since the issue is mainly in a "pull" scenario not necessarily push/pull). I'm mainly looking at deploying a Windows server at this branch office and either utilizing DFS-R or BranchCache. Looking at a table comparison and assuming we are looking at a "hosted branchcache server" and not simply distributed: It would appear there are benefits to both, even if both are "hosted" on a server. QUESTIONS I ACTUALLY HAVE: In what scenarios do each of these techs shine and where do you choose one over the other? Looking at a hosted Branchcache server, can you set "pre-fetching" of certain folders/files on the central file server so that they are immediately accessible locally at the branch? Do you have to do this on a schedule (if it is possible)? Looking at DFS-R my concern (and apparently solved with 3rd party apps) is file locking and making sure the file gets updated properly during a write operation (ie, making sure if both copies are accessed and both are written to, which file takes precedence and what happens to the changes?). Ideal it would seem would be to lock any alternate replicas of the data, but is it really that big of an issue? Does Branchcache lock the central file for editing? Does branchcache only transmit the deltas back to the central file of what has changed? Would either technology be ill advised if the branch office server was going to be utilized as a domain controller as well?

    Read the article

< Previous Page | 384 385 386 387 388 389 390 391 392 393 394 395  | Next Page >