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  • Talking JavaOne with Rock Star Simon Ritter

    - by Janice J. Heiss
    Oracle’s Java Technology Evangelist Simon Ritter is well known at JavaOne for his quirky and fun-loving sessions, which, this year include: CON4644 -- “JavaFX Extreme GUI Makeover” (with Angela Caicedo on how to improve UIs in JavaFX) CON5352 -- “Building JavaFX Interfaces for the Real World” (Kinect gesture tracking and mind reading) CON5348 -- “Do You Like Coffee with Your Dessert?” (Some cool demos of Java of the Raspberry Pi) CON6375 -- “Custom JavaFX Charts: (How to extend JavaFX Chart controls with some interesting things) I recently asked Ritter about the significance of the Raspberry Pi, the topic of one of his sessions that consists of a credit card-sized single-board computer developed in the UK with the intention of stimulating the teaching of basic computer science in schools. “I don't think there's one definitive thing that makes the RP significant,” observed Ritter, “but a combination of things that really makes it stand out. First, it's the cost: $35 for what is effectively a completely usable computer. OK, so you have to add a power supply, SD card for storage and maybe a screen, keyboard and mouse, but this is still way cheaper than a typical PC. The choice of an ARM processor is also significant, as it avoids problems like cooling (no heat sink or fan) and can use a USB power brick.  Combine these two things with the immense groundswell of community support and it provides a fantastic platform for teaching young and old alike about computing, which is the real goal of the project.”He informed me that he’ll be at the Raspberry Pi meetup on Saturday (not part of JavaOne). Check out the details here.JavaFX InterfacesWhen I asked about how JavaFX can interface with the real world, he said that there are many ways. “JavaFX provides you with a simple set of programming interfaces that can create complex, cool and compelling user interfaces,” explained Ritter. “Because it's just Java code you can combine JavaFX with any other Java library to provide data to display and control the interface. What I've done for my session is look at some of the possible ways of doing this using some of the amazing hardware that's available today at very low cost. The Kinect sensor has added a new dimension to gaming in terms of interaction; there's a Java API to access this so you can easily collect skeleton tracking data from it. Some clever people have also written libraries that can track gestures like swipes, circles, pushes, and so on. We use these to control parts of the UI. I've also experimented with a Neurosky EEG sensor that can in some ways ‘read your mind’ (well, at least measure some of the brain functions like attention and meditation).  I've written a Java library for this that I include as a way of controlling the UI. We're not quite at the stage of just thinking a command though!” Here Comes Java EmbeddedAnd what, from Ritter’s perspective, is the most exciting thing happening in the world of Java today? “I think it's seeing just how Java continues to become more and more pervasive,” he said. “One of the areas that is growing rapidly is embedded systems.  We've talked about the ‘Internet of things’ for many years; now it's finally becoming a reality. With the ability of more and more devices to include processing, storage and networking we need an easy way to write code for them that's reliable, has high performance, and is secure. Java fits all these requirements. With Java Embedded being a conference within a conference, I'm very excited about the possibilities of Java in this space.”Check out Ritter’s sessions or say hi if you run into him.

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  • Multiple URLs Single Server

    - by Amit
    Hi, In the DNS I have setup multiple URLs for my website (all pointing to same server). The entries in DNS looks like as below: Host TTL Numeric IP www .mysite.net 7200 192.168.31.12 @ (None) .mysite.net 7200 192.168.31.12 mycompany .mysite.net 7200 192.168.31.12 I wrote a code on Login.aspx page to check the URL and navigate to appropriate company login page. So if I type www.mysite.net or mysite.net then I am getting navigated to standard login page. But when I type mycompany.mysite.net still I am getting navigated to standard login page. But when I type https://mycompany.mysite.net then I am getting navigated to company specific login page. Why I need to type complete URL with https to get navigated to compay specific login page? Why it is not working just with mycompany.mysite.net? Any help of this is highly appriciated. Thanks, Amit

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  • Using the BackgroundWorker in a Silverlight MVVM Application

    - by axshon
    With Silverlight 4 and the Entity Framework you get a lot of work done on your behalf in terms of standard UI CRUD-style operations. Validations and I/O are pretty easy to accommodate out of the box. But sometimes you need to perform some long running tasks either on the client or on the server via service calls. To prevent your UI from hanging and annoying your users, you should consider placing these operations on a background thread. The BackgroundWorker object is the perfect solution for this...(read more)

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  • Native packaging for JavaFX

    - by igor
    JavaFX 2.2 adds new packaging option for JavaFX applications, allowing you to package your application as a "native bundle". This gives your users a way to install and run your application without any external dependencies on a system JRE or FX SDK. I'd like to give you an overview of what is it, motivation behind it, and finally explain how to get started with it. Screenshots may give you some idea of user experience but first hand experience is always the best. Before we go into all of the boring details, here are few different flavors of Ensemble for you to try: exe, msi, dmg, rpm installers and zip of linux bundle for non-rpm aware systems. Alternatively, check out native packages for JFXtras 2. Whats wrong with existing deployment options? JavaFX 2 applications are easy to distribute as a standalone application or as an application deployed on the web (embedded in the web page or as link to launch application from the webpage). JavaFX packaging tools, such as ant tasks and javafxpackager utility, simplify the creation of deployment packages even further. Why add new deployment options? JavaFX applications have implicit dependency on the availability of Java and JavaFX runtimes, and while existing deployment methods provide a means to validate the system requirements are met -- and even guide user to perform required installation/upgrades -- they do not fully address all of the important scenarios. In particular, here are few examples: the user may not have admin permissions to install new system software if the application was certified to run in the specific environment (fixed version of Java and JavaFX) then it may be hard to ensure user has this environment due to an autoupdate of the system version of Java/JavaFX (to ensure they are secure). Potentially, other apps may have a requirement for a different JRE or FX version that your app is incompatible with. your distribution channel may disallow dependencies on external frameworks (e.g. Mac AppStore) What is a "native package" for JavaFX application? In short it is  A Wrapper for your JavaFX application that makes is into a platform-specific application bundle Each Bundle is self-contained and includes your application code and resources (same set as need to launch standalone application from jar) Java and JavaFX runtimes (private copies to be used by this application only) native application launcher  metadata (icons, etc.) No separate installation is needed for Java and JavaFX runtimes Can be distributed as .zip or packaged as platform-specific installer No application changes, the same jar app binaries can be deployed as a native bundle, double-clickable jar, applet, or web start app What is good about it: Easy deployment of your application on fresh systems, without admin permissions when using .zip or a user-level installer No-hassle compatibility.  Your application is using a private copy of Java and JavaFX. The developer (you!) controls when these are updated. Easily package your application for Mac AppStore (or Windows, or...) Process name of running application is named after your application (and not just java.exe)  Easily deploy your application using enterprise deployment tools (e.g. deploy as MSI) Support is built in into JDK 7u6 (that includes JavaFX 2.2) Is it a silver bullet for the deployment that other deployment options will be deprecated? No.  There are no plans to deprecate other deployment options supported by JavaFX, each approach addresses different needs. Deciding whether native packaging is a best way to deploy your application depends on your requirements. A few caveats to consider: "Download and run" user experienceUnlike web deployment, the user experience is not about "launch app from web". It is more of "download, install and run" process, and the user may need to go through additional steps to get application launched - e.g. accepting a browser security dialog or finding and launching the application installer from "downloads" folder. Larger download sizeIn general size of bundled application will be noticeably higher than size of unbundled app as a private copy of the JRE and JavaFX are included.  We're working to reduce the size through compression and customizable "trimming", but it will always be substantially larger than than an app that depends on a "system JRE". Bundle per target platformBundle formats are platform specific. Currently a native bundle can only be produced for the same system you are building on.  That is, if you want to deliver native app bundles on Windows, Linux and Mac you will have to build your project on all three platforms. Application updates are the responsibility of developerWeb deployed Java applications automatically download application updates from the web as soon as they are available. The Java Autoupdate mechanism takes care of updating the Java and JavaFX runtimes to latest secure version several times every year. There is no built in support for this in for bundled applications. It is possible to use 3rd party libraries (like Sparkle on Mac) to add autoupdate support at application level.  In a future version of JavaFX we may include built-in support for autoupdate (add yourself as watcher for RT-22211 if you are interested in this) Getting started with native bundles First, you need to get the latest JDK 7u6 beta build (build 14 or later is recommended). On Windows/Mac/Linux it comes with JavaFX 2.2 SDK as part of JDK installation and contains JavaFX packaging tools, including: bin/javafxpackagerCommand line utility to produce JavaFX packages. lib/ant-javafx.jar Set of ant tasks to produce JavaFX packages (most recommended way to deploy apps) For general information on how to use them refer to the Deploying JavaFX Application guide. Once you know how use these tools to package your JavaFX application for other deployment methods there are only a few minor tweaks necessary to produce native bundles: make sure java is used from JDK7u6 bundle you have installed adjust your PATH settings if needed  if you are using ant tasks add "nativeBundles=all" attribute to fx:deploy task if you are using javafxpackager pass "-native" option to deploy command or if you are using makeall command then it will try build native packages by default result bundles will be in the "bundles" folder next to other deployment artifacts Note that building some types of native packages (e.g. .exe or .msi) may require additional free 3rd party software to be installed and available on PATH. As of JDK 7u6 build 14 you could build following types of packages: Windows bundle image EXE Inno Setup 5 or later is required Result exe will perform user level installation (no admin permissions are required) At least one shortcut will be created (menu or desktop) Application will be launched at the end of install MSI WiX 3.0 or later is required Result MSI will perform user level installation (no admin permissions are required) At least one shortcut will be created (menu or desktop)  MacOS bundle image dmg (drag and drop) installer Linux bundle image rpm rpmbuild is required shortcut will be added to the programs menu If you are using Netbeans for producing the deployment packages then you will need to add custom build step to the build.xml to execute the fx:deploy task with native bundles enabled. Here is what we do for BrickBreaker sample: <target name="-post-jfx-deploy"> <fx:deploy width="${javafx.run.width}" height="${javafx.run.height}" nativeBundles="all" outdir="${basedir}/${dist.dir}" outfile="${application.title}"> <fx:application name="${application.title}" mainClass="${javafx.main.class}"> <fx:resources> <fx:fileset dir="${basedir}/${dist.dir}" includes="BrickBreaker.jar"/> </fx:resources> <info title="${application.title}" vendor="${application.vendor}"/> </fx:application> </fx:deploy> </target> This is pretty much regular use of fx:deploy task, the only special thing here is nativeBundles="all". Perhaps the easiest way to try building native bundles is to download the latest JavaFX samples bundle and build Ensemble, BrickBreaker or SwingInterop. Please give it a try and share your experience. We need your feedback! BTW, do not hesitate to file bugs and feature requests to JavaFX bug database! Wait! How can i ... This entry is not a comprehensive guide into native bundles, and we plan to post on this topic more. However, I am sure that once you play with native bundles you will have a lot of questions. We may not have all the answers, but please do not hesitate to ask! Knowing all of the questions is the first step to finding all of the answers.

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  • Sun Fire X4800 M2 Posts World Record x86 SPECjEnterprise2010 Result

    - by Brian
    Oracle's Sun Fire X4800 M2 using the Intel Xeon E7-8870 processor and Sun Fire X4470 M2 using the Intel Xeon E7-4870 processor, produced a world record single application server SPECjEnterprise2010 benchmark result of 27,150.05 SPECjEnterprise2010 EjOPS. The Sun Fire X4800 M2 server ran the application tier and the Sun Fire X4470 M2 server was used for the database tier. The Sun Fire X4800 M2 server demonstrated 63% better performance compared to IBM P780 server result of 16,646.34 SPECjEnterprise2010 EjOPS. The Sun Fire X4800 M2 server demonstrated 4% better performance than the Cisco UCS B440 M2 result, both results used the same number of processors. This result used Oracle WebLogic Server 12c, Java HotSpot(TM) 64-Bit Server 1.7.0_02, and Oracle Database 11g. This result was produced using Oracle Linux. Performance Landscape Complete benchmark results are at the SPEC website, SPECjEnterprise2010 Results. The table below compares against the best results from IBM and Cisco. SPECjEnterprise2010 Performance Chart as of 3/12/2012 Submitter EjOPS* Application Server Database Server Oracle 27,150.05 1x Sun Fire X4800 M2 8x 2.4 GHz Intel Xeon E7-8870 Oracle WebLogic 12c 1x Sun Fire X4470 M2 4x 2.4 GHz Intel Xeon E7-4870 Oracle Database 11g (11.2.0.2) Cisco 26,118.67 2x UCS B440 M2 Blade Server 4x 2.4 GHz Intel Xeon E7-4870 Oracle WebLogic 11g (10.3.5) 1x UCS C460 M2 Blade Server 4x 2.4 GHz Intel Xeon E7-4870 Oracle Database 11g (11.2.0.2) IBM 16,646.34 1x IBM Power 780 8x 3.86 GHz POWER 7 WebSphere Application Server V7 1x IBM Power 750 Express 4x 3.55 GHz POWER 7 IBM DB2 9.7 Workgroup Server Edition FP3a * SPECjEnterprise2010 EjOPS, bigger is better. Configuration Summary Application Server: 1 x Sun Fire X4800 M2 8 x 2.4 GHz Intel Xeon processor E7-8870 256 GB memory 4 x 10 GbE NIC 2 x FC HBA Oracle Linux 5 Update 6 Oracle WebLogic Server 11g Release 1 (10.3.5) Java HotSpot(TM) 64-Bit Server VM on Linux, version 1.7.0_02 (Java SE 7 Update 2) Database Server: 1 x Sun Fire X4470 M2 4 x 2.4 GHz Intel Xeon E7-4870 512 GB memory 4 x 10 GbE NIC 2 x FC HBA 2 x Sun StorageTek 2540 M2 4 x Sun Fire X4270 M2 4 x Sun Storage F5100 Flash Array Oracle Linux 5 Update 6 Oracle Database 11g Enterprise Edition Release 11.2.0.2 Benchmark Description SPECjEnterprise2010 is the third generation of the SPEC organization's J2EE end-to-end industry standard benchmark application. The SPECjEnterprise2010 benchmark has been designed and developed to cover the Java EE 5 specification's significantly expanded and simplified programming model, highlighting the major features used by developers in the industry today. This provides a real world workload driving the Application Server's implementation of the Java EE specification to its maximum potential and allowing maximum stressing of the underlying hardware and software systems. The workload consists of an end to end web based order processing domain, an RMI and Web Services driven manufacturing domain and a supply chain model utilizing document based Web Services. The application is a collection of Java classes, Java Servlets, Java Server Pages, Enterprise Java Beans, Java Persistence Entities (pojo's) and Message Driven Beans. The SPECjEnterprise2010 benchmark heavily exercises all parts of the underlying infrastructure that make up the application environment, including hardware, JVM software, database software, JDBC drivers, and the system network. The primary metric of the SPECjEnterprise2010 benchmark is jEnterprise Operations Per Second ("SPECjEnterprise2010 EjOPS"). This metric is calculated by adding the metrics of the Dealership Management Application in the Dealer Domain and the Manufacturing Application in the Manufacturing Domain. There is no price/performance metric in this benchmark. Key Points and Best Practices Sixteen Oracle WebLogic server instances were started using numactl, binding 2 instances per chip. Eight Oracle database listener processes were started, binding 2 instances per chip using taskset. Additional tuning information is in the report at http://spec.org. See Also Oracle Press Release -- SPECjEnterprise2010 Results Page Sun Fire X4800 M2 Server oracle.com OTN Sun Fire X4270 M2 Server oracle.com OTN Sun Storage 2540-M2 Array oracle.com OTN Oracle Linux oracle.com OTN Oracle Database 11g Release 2 Enterprise Edition oracle.com OTN WebLogic Suite oracle.com OTN Disclosure Statement SPEC and the benchmark name SPECjEnterprise are registered trademarks of the Standard Performance Evaluation Corporation. Sun Fire X4800 M2, 27,150.05 SPECjEnterprise2010 EjOPS; IBM Power 780, 16,646.34 SPECjEnterprise2010 EjOPS; Cisco UCS B440 M2, 26,118.67 SPECjEnterprise2010 EjOPS. Results from www.spec.org as of 3/27/2012.

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  • July, the 31 Days of SQL Server DMO’s – Day 23 (sys.dm_db_index_usage_stats)

    - by Tamarick Hill
    The sys.dm_db_index_usage_stats Dynamic Management View is used to return usage information about the various indexes on your SQL Server instance. Let’s have a look at this DMV against our AdventureWorks2012 database so we can examine the information returned. SELECT * FROM sys.dm_db_index_usage_stats WHERE database_id = db_id('AdventureWorks2012') The first three columns in the result set represent the database_id, object_id, and index_id of a given row. You can join these columns back to other system tables to extract the actual database, object, and index names. The next four columns are probably the most beneficial columns within this DMV. First, the user_seeks column represents the number of times that a user query caused a seek operation against a particular index. The user_scans column represents how many times a user query caused a scan operation on a particular index. The user_lookups column represents how many times an index was used to perform a lookup operation. The user_updates column refers to how many times an index had to be updated due to a write operation that effected a particular index. The last_user_seek, last_user_scan, last_user_lookup, and last_user_update columns provide you with DATETIME information about when the last user scan, seek, lookup, or update operation was performed. The remaining columns in the result set are the same as the ones we previously discussed, except instead of the various operations being generated from user requests, they are generated from system background requests. This is an extremely useful DMV and one of my favorites when it comes to Index Maintenance. As we all know, indexes are extremely beneficial with improving the performance of your read operations. But indexes do have a downside as well. Indexes slow down the performance of your write operations, and they also require additional resources for storage. For this reason, in my opinion, it is important to regularly analyze the indexes on your system to make sure the indexes you have are being used efficiently. My AdventureWorks2012 database is only used for demonstrating or testing things, so I dont have a lot of meaningful information here, but for a Production system, if you see an index that is never getting any seeks, scans, or lookups, but is constantly getting a ton of updates, it more than likely would be a good candidate for you to consider removing. You would not be getting much benefit from the index, but yet it is incurring a cost on your system due to it constantly having to be updated for your write operations, not to mention the additional storage it is consuming. You should regularly analyze your indexes to ensure you keep your database systems as efficient and lean as possible. One thing to note is that these DMV statistics are reset every time SQL Server is restarted. Therefore it would not be a wise idea to make decisions about removing indexes after a Server Reboot or a cluster roll. If you restart your SQL Server instances frequently, for example if you schedule weekly/monthly cluster rolls, then you may not capture indexes that are being used for weekly/monthly reports that run for business users. And if you remove them, you may have some upset people at your desk on Monday morning. If you would like to begin analyzing your indexes to possibly remove the ones that your system is not using, I would recommend building a process to load this DMV information into a table on scheduled basis, depending on how frequently you perform an operation that would reset these statistics, then you can analyze the data over a period of time to get a more accurate view of what indexes are really being used and which ones or not. For more information about this DMV, please see the below Books Online link: http://msdn.microsoft.com/en-us/library/ms188755.aspx Follow me on Twitter @PrimeTimeDBA

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  • Télécharger un fichier du Web avec PyQt4 et QThread, un article de Jean-Paul Vidal

    Bonjour, Je vous informe d'un nouveau tuto sur developpez : comment télécharger un fichier sur le Web avec PyQt4. Le code utilise QThread (le thread de Qt4) et, pour le téléchargement, le module urllib. Il permet de montrer comment les threads peuvent communiquer par messages avec l'interface graphique afin de mettre à jour une barre de progression du téléchargement. Il a été développé suite au fil de discussion http://www.developpez.net/forums/d10...s-urlretrieve/. Tyrtamos...

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  • SQL SERVER – PREEMPTIVE and Non-PREEMPTIVE – Wait Type – Day 19 of 28

    - by pinaldave
    In this blog post, we are going to talk about a very interesting subject. I often get questions related to SQL Server 2008 Book-Online about various Preemptive wait types. I got a few questions asking what these wait types are and how they could be interpreted. To get current wait types of the system, you can read this article and run the script: SQL SERVER – DMV – sys.dm_os_waiting_tasks and sys.dm_exec_requests – Wait Type – Day 4 of 28. Before we continue understanding them, let us study first what PREEMPTIVE and Non-PREEMPTIVE waits in SQL Server mean. PREEMPTIVE: Simply put, this wait means non-cooperative. While SQL Server is executing a task, the Operating System (OS) interrupts it. This leads to SQL Server to involuntarily give up the execution for other higher priority tasks. This is not good for SQL Server as it is a particular external process which makes SQL Server to yield. This kind of wait can reduce the performance drastically and needs to be investigated properly. Non-PREEMPTIVE: In simple terms, this wait means cooperative. SQL Server manages the scheduling of the threads. When SQL Server manages the scheduling instead of the OS, it makes sure its own priority. In this case, SQL Server decides the priority and one thread yields to another thread voluntarily. In the earlier version of SQL Server, there was no preemptive wait types mentioned and the associated task status with them was marked as suspended. In SQL Server 2005, preemptive wait types were not listed as well, but their associated task status was marked as running. In SQL Server 2008, preemptive wait types are properly listed and their associated task status is also marked as running. Now, SQL Server is in Non-Preemptive mode by default and it works fine. When CLR, extended Stored Procedures and other external components run, they run in Preemptive mode, leading to the creation of these wait types. There are a wide variety of preemptive wait types. If you see consistent high value in the Preemptive wait types, I strongly suggest that you look into the wait type and try to know the root cause. If you are still not sure, you can send me an email or leave a comment about it and I will do my best to help you reduce this wait type. Read all the post in the Wait Types and Queue series. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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  • Oracle 64-bit assembly throws BadImageFormatException when running unit tests

    - by pjohnson
    We recently upgraded to the 64-bit Oracle client. Since then, Visual Studio 2010 unit tests that hit the database (I know, unit tests shouldn't hit the database--they're not perfect) all fail with this error message:Test method MyProject.Test.SomeTest threw exception: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.BadImageFormatException: Could not load file or assembly 'Oracle.DataAccess, Version=4.112.3.0, Culture=neutral, PublicKeyToken=89b483f429c47342' or one of its dependencies. An attempt was made to load a program with an incorrect format.I resolved this by changing the test settings to run tests in 64-bit. From the Test menu, go to Edit Test Settings, and pick your settings file. Go to Hosts, and change the "Run tests in 32 bit or 64 bit process" dropdown to "Run tests in 64 bit process on 64 bit machine". Now your tests should run.This fix makes me a little nervous. Visual Studio 2010 and earlier seem to change that file for no apparent reason, add more settings files, etc. If you're not paying attention, you could have TestSettings1.testsettings through TestSettings99.testsettings sitting there and never notice the difference. So it's worth making a note of how to change it in case you have to redo it, and being vigilant about files VS tries to add.I'm not entirely clear on why this was even a problem. Isn't that the point of an MSIL assembly, that it's not specific to the hardware it runs on? An IL disassembler can open the Oracle.DataAccess.dll in question, and in its Runtime property, I see the value "v4.0.30319 / x64". So I guess the assembly was specifically build to target 64-bit platforms only, possibly due to a 64-bit-specific difference in the external Oracle client upon which it depends. Most other assemblies, especially in the .NET Framework, list "msil", and a couple list "x86". So I guess this is another entry in the long list of ways Oracle refuses to play nice with Windows and .NET.If this doesn't solve your problem, you can read others' research into this error, and where to change the same test setting in Visual Studio 2012.

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  • Does this file format exist?

    - by Jon Chase
    Is there a file format that handles the following use case... I'd like to create a tar file (or whatever - I'm just using tar here b/c it's a well known file format for containing multiple files) that would be usable even if I only had access to specific chunks of said file. For example, say I tar up my mp3 and photo collection into a 100GB tar file, then put the file into some long term storage somewhere. Later, I want to access a specific mp3 file. I don't want to download the entire 100GB tar file just to get to one mp3. In fact, let's say I can't download the entire 100GB tar file. Instead, I'd like to say "give me megabytes 10 through 19 of the 100GB tar file" and then have the mp3 magically extracted from those 10 megabytes. Does a file format like this exist?

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  • What's The Difference Between Imperative, Procedural and Structured Programming?

    - by daniels
    By researching around (books, Wikipedia, similar questions on SE, etc) I came to understand that Imperative programming is one of the major programming paradigms, where you describe a series of commands (or statements) for the computer to execute (so you pretty much order it to take specific actions, hence the name "imperative"). So far so good. Procedural programming, on the other hand, is a specific type (or subset) of Imperative programming, where you use procedures (i.e., functions) to describe the commands the computer should perform. First question: Is there an Imperative programming language which is not procedural? In other words, can you have Imperative programming without procedures? Update: This first question seems to be answered. A language CAN be imperative without being procedural or structured. An example is pure Assembly language. Then you also have Structured programming, which seems to be another type (or subset) of Imperative programming, which emerged to remove the reliance on the GOTO statement. Second question: What is the difference between procedural and structured programming? Can you have one without the other, and vice-versa? Can we say procedural programming is a subset of structured programming, as in the image?

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  • How to cross-reference many character encodings with ASCII OR UTFx?

    - by Garet Claborn
    I'm working with a binary structure, the goal of which is to index the significance of specific bits for any character encoding so that we may trigger events while doing specific checks against the profile. Each character encoding scheme has an associated system record. This record's leading value will be a C++ unsigned long long binary value and signifies the length, in bits, of encoded characters. Following the length are three values, each is a bit field of that length. offset_mask - defines the occurrence of non-printable characters within the min,max of print_mask range_mask - defines the occurrence of the most popular 50% of printable characters print_mask - defines the occurrence value of printable characters The structure of profiles has changed from the op of this question. Most likely I will try to factorize or compress these values in the long-term instead of starting out with ranges after reading more. I have to write some of the core functionality for these main reasons. It has to fit into a particular event architecture we are using, Better understanding of character encoding. I'm about to need it. Integrating into non-linear design is excluding many libraries without special hooks. I'm unsure if there is a standard, cross-encoding mechanism for communicating such data already. I'm just starting to look into how chardet might do profiling as suggested by @amon. The Unicode BOM would be easily enough (for my current project) if all encodings were Unicode. Of course ideally, one would like to support all encodings, but I'm not asking about implementation - only the general case. How can these profiles be efficiently populated, to produce a set of bitmasks which we can use to match strings with common characters in multiple languages? If you have any editing suggestions please feel free, I am a lightweight when it comes to localization, which is why I'm trying to reach out to the more experienced. Any caveats you may be able to help with will be appreciated.

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  • How to implement curved movement while tracking the appropriate angle?

    - by Vexille
    I'm currently coding a 2D top-down car game which will be turn-based. And since it's turn-based, the cars won't be controlled directly (i.e. with a simple velocity vector that adjusts its angle when the player wants to turn), but instead it's movement path has to be planned beforehand, and then the car needs to follow the path when the turn ends (think Steambirds). This question has some interesting information, but its focus is on homing-missile behaviour, which I kinda had figured out, but doesn't really apply to my case, I think, since I need to show a preview of the path when the player is planning his turn, then have the car follow that path. In that same question, there's an excellent answer by Andrew Russel which mentions Equations of Motion and Bézier's Curve. Some of his other suggestions of implementation are specific to XNA though, so they don't help much (I'm using Marmalade SDK). If I assume Bézier's Curve as the solution of choice, I'm left with one specific problem: I'll have the car's position (the first endpoint) and the target/final position (the last endpoint), but what should I use as the control point (assuming a square/quadratic curve)? And whether I use Bézier's Curve or another parametric equation, I'd still be left with another issue: the car can't just follow the curve, it must turn (i.e. adjust its angle) accordingly. So how can I figure out which way the car should be pointing to at any given point in the curve?

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  • Big Data for Retail

    - by David Dorf
    Right up there with mobile, social, and cloud is the term "big data," which seems to be popping up lots in the press these days.  Companies like Google, Yahoo, and Facebook have popularized a new class of data technologies meant to solve the problem of processing large amounts of data quickly.  I first mentioned this in a posting back in March 2009.  Put simply, big data implies datasets so large they can't normally be processed using a standard transactional database.  The term "noSQL" is often used in this context as well. Actually, using parallel processing within the Oracle database combined with Exadata can achieve impressive results.  Look for more from Oracle at OpenWorld as hinted by Jean-Pierre Dijcks. McKinsey recently released a report on big data in which retail was specifically mentioned as an industry that can benefit from the new technologies.  I won't rehash that report because my friend Rama already did such a good job in his posting, Impact of "Big Data" on Retail. The presentation below does a pretty good job of framing the problem, although it doesn't really get into the available technologies (e.g. Exadata, Hadoop, Cassandra, etc.) and isn't retail specific. Determine the Right Analytic Database: A Survey of New Data Technologies So when a retailer asks me about big data, here's what I say:  Big data refers to a set of technologies for processing large volumes of structured and unstructured data.  Imagine collecting everything uttered by your customers on Facebook and Twitter and combining it with all the data you can find about the products you sell (e.g. reviews, images, demonstration videos), including competitive data.  Assuming you could process all that data, you could then personalize offers to specific customers based on their tastes, ensure prices are competitive, and implement better local assortments.  It's really not that far off.

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  • Wifi ap finder/selector for windows 7

    - by wag2639
    Is there wifi finder program for windows 7 that can let me choose specific access points to connect to? In my school, the wifi network uses the same SSID for numerous access points and usually the default wifi finder in Windows 7 connects to the first one. Even if it connects to the closest one with the best signal, there are times when a specific access point will not work. Machine: Lenovo IdeaPad S10-2 running Windows 7 (32bit) Note: On my ThinkPad, I've got access connection that does the job but that didn't seem to work on the IdeaPad the last time I tried.

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  • SQLAuthority News – 2 Whitepapers Announced – AlwaysOn Architecture Guide: Building a High Availability and Disaster Recovery Solution

    - by pinaldave
    Understanding AlwaysOn Architecture is extremely important when building a solution with failover clusters and availability groups. Microsoft has just released two very important white papers related to this subject. Both the white papers are written by top experts in industry and have been reviewed by excellent panel of experts. Every time I talk with various organizations who are adopting the SQL Server 2012 they are always excited with the concept of the new feature AlwaysOn. One of the requests I often here is the related to detailed documentations which can help enterprises to build a robust high availability and disaster recovery solution. I believe following two white paper now satisfies the request. AlwaysOn Architecture Guide: Building a High Availability and Disaster Recovery Solution by Using AlwaysOn Availability Groups SQL Server 2012 AlwaysOn Availability Groups provides a unified high availability and disaster recovery (HADR) solution. This paper details the key topology requirements of this specific design pattern on important concepts like quorum configuration considerations, steps required to build the environment, and a workflow that shows how to handle a disaster recovery. AlwaysOn Architecture Guide: Building a High Availability and Disaster Recovery Solution by Using Failover Cluster Instances and Availability Groups SQL Server 2012 AlwaysOn Failover Cluster Instances (FCI) and AlwaysOn Availability Groups provide a comprehensive high availability and disaster recovery solution. This paper details the key topology requirements of this specific design pattern on important concepts like asymmetric storage considerations, quorum model selection, quorum votes, steps required to build the environment, and a workflow. If you are not going to implement AlwaysOn feature, this two Whitepapers are still a great reference material to review as it will give you complete idea regarding what it takes to implement AlwaysOn architecture and what kind of efforts needed. One should at least bookmark above two white papers for future reference. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Documentation, SQL Download, SQL Query, SQL Server, SQL Tips and Tricks, SQL White Papers, T SQL, Technology Tagged: AlwaysOn

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  • Programming concepts taken from the arts and humanities

    - by Joey Adams
    After reading Paul Graham's essay Hackers and Painters and Joel Spolsky's Advice for Computer Science College Students, I think I've finally gotten it through my thick skull that I should not be loath to work hard in academic courses that aren't "programming" or "computer science" courses. To quote the former: I've found that the best sources of ideas are not the other fields that have the word "computer" in their names, but the other fields inhabited by makers. Painting has been a much richer source of ideas than the theory of computation. — Paul Graham, "Hackers and Painters" There are certainly other, much stronger reasons to work hard in the "boring" classes. However, it'd also be neat to know that these classes may someday inspire me in programming. My question is: what are some specific examples where ideas from literature, art, humanities, philosophy, and other fields made their way into programming? In particular, ideas that weren't obviously applied the way they were meant to (like most math and domain-specific knowledge), but instead gave utterance or inspiration to a program's design and choice of names. Good examples: The term endian comes from Gulliver's Travels by Tom Swift (see here), where it refers to the trivial matter of which side people crack open their eggs. The terms journal and transaction refer to nearly identical concepts in both filesystem design and double-entry bookkeeping (financial accounting). mkfs.ext2 even says: Writing superblocks and filesystem accounting information: done Off-topic: Learning to write English well is important, as it enables a programmer to document and evangelize his/her software, as well as appear competent to other programmers online. Trigonometry is used in 2D and 3D games to implement rotation and direction aspects. Knowing finance will come in handy if you want to write an accounting package. Knowing XYZ will come in handy if you want to write an XYZ package. Arguably on-topic: The Monad class in Haskell is based on a concept by the same name from category theory. Actually, Monads in Haskell are monads in the category of Haskell types and functions. Whatever that means...

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  • Oracle TimesTen In-Memory Database Performance on SPARC T4-2

    - by Brian
    The Oracle TimesTen In-Memory Database is optimized to run on Oracle's SPARC T4 processor platforms running Oracle Solaris 11 providing unsurpassed scalability, performance, upgradability, protection of investment and return on investment. The following demonstrate the value of combining Oracle TimesTen In-Memory Database with SPARC T4 servers and Oracle Solaris 11: On a Mobile Call Processing test, the 2-socket SPARC T4-2 server outperforms: Oracle's SPARC Enterprise M4000 server (4 x 2.66 GHz SPARC64 VII+) by 34%. Oracle's SPARC T3-4 (4 x 1.65 GHz SPARC T3) by 2.7x, or 5.4x per processor. Utilizing the TimesTen Performance Throughput Benchmark (TPTBM), the SPARC T4-2 server protects investments with: 2.1x the overall performance of a 4-socket SPARC Enterprise M4000 server in read-only mode and 1.5x the performance in update-only testing. This is 4.2x more performance per processor than the SPARC64 VII+ 2.66 GHz based system. 10x more performance per processor than the SPARC T2+ 1.4 GHz server. 1.6x better performance per processor than the SPARC T3 1.65 GHz based server. In replication testing, the two socket SPARC T4-2 server is over 3x faster than the performance of a four socket SPARC Enterprise T5440 server in both asynchronous replication environment and the highly available 2-Safe replication. This testing emphasizes parallel replication between systems. Performance Landscape Mobile Call Processing Test Performance System Processor Sockets/Cores/Threads Tps SPARC T4-2 SPARC T4, 2.85 GHz 2 16 128 218,400 M4000 SPARC64 VII+, 2.66 GHz 4 16 32 162,900 SPARC T3-4 SPARC T3, 1.65 GHz 4 64 512 80,400 TimesTen Performance Throughput Benchmark (TPTBM) Read-Only System Processor Sockets/Cores/Threads Tps SPARC T3-4 SPARC T3, 1.65 GHz 4 64 512 7.9M SPARC T4-2 SPARC T4, 2.85 GHz 2 16 128 6.5M M4000 SPARC64 VII+, 2.66 GHz 4 16 32 3.1M T5440 SPARC T2+, 1.4 GHz 4 32 256 3.1M TimesTen Performance Throughput Benchmark (TPTBM) Update-Only System Processor Sockets/Cores/Threads Tps SPARC T4-2 SPARC T4, 2.85 GHz 2 16 128 547,800 M4000 SPARC64 VII+, 2.66 GHz 4 16 32 363,800 SPARC T3-4 SPARC T3, 1.65 GHz 4 64 512 240,500 TimesTen Replication Tests System Processor Sockets/Cores/Threads Asynchronous 2-Safe SPARC T4-2 SPARC T4, 2.85 GHz 2 16 128 38,024 13,701 SPARC T5440 SPARC T2+, 1.4 GHz 4 32 256 11,621 4,615 Configuration Summary Hardware Configurations: SPARC T4-2 server 2 x SPARC T4 processors, 2.85 GHz 256 GB memory 1 x 8 Gbs FC Qlogic HBA 1 x 6 Gbs SAS HBA 4 x 300 GB internal disks Sun Storage F5100 Flash Array (40 x 24 GB flash modules) 1 x Sun Fire X4275 server configured as COMSTAR head SPARC T3-4 server 4 x SPARC T3 processors, 1.6 GHz 512 GB memory 1 x 8 Gbs FC Qlogic HBA 8 x 146 GB internal disks 1 x Sun Fire X4275 server configured as COMSTAR head SPARC Enterprise M4000 server 4 x SPARC64 VII+ processors, 2.66 GHz 128 GB memory 1 x 8 Gbs FC Qlogic HBA 1 x 6 Gbs SAS HBA 2 x 146 GB internal disks Sun Storage F5100 Flash Array (40 x 24 GB flash modules) 1 x Sun Fire X4275 server configured as COMSTAR head Software Configuration: Oracle Solaris 11 11/11 Oracle TimesTen 11.2.2.4 Benchmark Descriptions TimesTen Performance Throughput BenchMark (TPTBM) is shipped with TimesTen and measures the total throughput of the system. The workload can test read-only, update-only, delete and insert operations as required. Mobile Call Processing is a customer-based workload for processing calls made by mobile phone subscribers. The workload has a mixture of read-only, update, and insert-only transactions. The peak throughput performance is measured from multiple concurrent processes executing the transactions until a peak performance is reached via saturation of the available resources. Parallel Replication tests using both asynchronous and 2-Safe replication methods. For asynchronous replication, transactions are processed in batches to maximize the throughput capabilities of the replication server and network. In 2-Safe replication, also known as no data-loss or high availability, transactions are replicated between servers immediately emphasizing low latency. For both environments, performance is measured in the number of parallel replication servers and the maximum transactions-per-second for all concurrent processes. See Also SPARC T4-2 Server oracle.com OTN Oracle TimesTen In-Memory Database oracle.com OTN Oracle Solaris oracle.com OTN Oracle Database 11g Release 2 Enterprise Edition oracle.com OTN Disclosure Statement Copyright 2012, Oracle and/or its affiliates. All rights reserved. Oracle and Java are registered trademarks of Oracle and/or its affiliates. Other names may be trademarks of their respective owners. Results as of 1 October 2012.

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  • GPLv2 - Multiple AI chess engines to bypass GPL

    - by Dogbert
    I have gone through a number of GPL-related questions, the most recent being this one: http://stackoverflow.com/questions/3248823/legal-question-about-the-gpl-license-net-dlls/3249001#3249001 I'm trying to see how this would work, so bear with me. I have a simple GUI interface for a game of Chess. It essentially can send/receive commands to/from an external chess engine (ie: Tong, Fruit, etc). The application/GUI is similar in nature to XBoard ( http://www.gnu.org/software/xboard/ ), but was independently designed. After going through a number of threads on this topic, it seems that the FSF considers dynamically linking against a GPLv2 library as a derivative work, and that by doing so, the GPLv2 extends to my proprietary code, and I must release the source to my entire project. Other legal precedents indicate the opposite, and that dynamic linking doesn't cause the "viral" effect of the GPL to propagate to my proprietary code. Since there is no official consensus that can give a "hard-and-fast" answer to the dynamic linking question, would this be an acceptable alternative: I build my chess GUI so that it sends/receives the chess engine AI logic as text commands from an external interface library that I write The interface library I wrote itself is then released under the GPL The interface library is only used to communicate via a generic text pipe to external command-line chess engines The chess engine itself would be built as a command-line utility rather than as a library of any sort, and just sends strings in the Universal Chess Interface of Chess Engine Communication Protocol ( http://en.wikipedia.org/wiki/Chess_Engine_Communication_Protocol ) format. The one "gotcha" is that the interface library should not be specific to one single GPL'ed chess engine, otherwise the entire GUI would be "entirely dependent" on it. So, I just make my interface library so that it is able to connect to any command-line chess engine that uses a specific format, rather than just one unique engine. I could then include pre-built command-line-app versions of any of the chess engines I'm using. Would that sort of approach allow me to do the following: NOT release the source for my UI Release the source of the interface library I built (if necessary) Use one or more chess engines and bundle them as external command-line utilities that ship with a binary version of my UI Thank you.

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  • Silverlight Cream for May 13, 2010 -- #861

    - by Dave Campbell
    In this Issue: Sigurd Snørteland, Jeff Prosise, DaveDev, Joe Zhou, Chris Eargle, John Papa(-2-, -3-), and David Anson(-2-). Shoutouts: In with the links I've listed below, Sigurd Snørteland also sent a link to this app he's working on which is actually pretty cool to see: ZuneLight. The code is not yet available. He also has a no-code demo of a Silverlight Media Center Pieter Voloshyn, Luiz Thadeu, and Jhun Iti have a very nice Silverlight image editor up: Thumba From SilverlightCream.com: WP7 - Silverlight on mobile Sigurd Snørteland submitted some links for me that have been translated to English from his blog. I hope the pages come out good because he's got a lot of good stuff on there. This one has a link to a presentation he did, and 4 projects you can load up in the emulator that he's converted to the phone: weather, worldclock, coverflow, and solitaire ... pretty cool... thanks for the links Sigurd! Understanding Page Orientation in Silverlight for Windows Phone Jeff Prosise has a really nice post up on page orientation in WP7 ... what it means to your app, how to detect it, and example code for what to do then... also love a quote by Jeff: "Silverlight for Windows Phone is the hottest thing since color TV" Why you should check out Expression Blend Behaviors when using Silverlight DaveDev has a post up describing Behaviors and why we should use them, plus tons of external links to resources, blogs, videos... all good stuff... Fiddler inspector for WCF Silverlight Polling Duplex and WCF RIA Joe Zhou announces and provides a link to a new Fiddler inspector that understands the framing in Polling Duplex and also raw binary xml and binary SOAP. Windows Phone Controls v0.7 Chris Eargle reports the release of Version 0.7 of the Windows Phone Controls project on CodePlex ... this includes a Pivot Control and a Panorama Control... both very nicely done. Binding to Silverlight ComboBox and Using SelectedValue, SelectedValuePath and DisplayMemberPath John Papa responds to a user question and put up a nice post about binding to a ComboBox and then go from the selected item to some other property ... code included No More Boxes! Exploring the PathListBox (Silverlight TV #25) Silverlight TV 25 went up on Tuesday ... thought it was going to be Thursday?? anyway ... John Papa and Adam Kinney are discussing the PathListBox and looking at some cool demos thereof. Exposing SOAP, OData, and JSON Endpoints for RIA Services (Silverlight TV 26) Since today IS Thursday, we have a new Silverlight TV, number 26, and John Papa is chatting with Deepesh Mohnani of the WCF RIA Services team about exposing all sorts of endpoints... should be something in there for everybody :) Workaround for a Silverlight data binding bug affecting various scenarios - including DataGrid+ContextMenu David Anson details the rabbit-trail he and others on the team followed in response to a problem reported via Twitter where the binding on a DataGrid seemed off by a row(!) ... weird but true, validated, and SL3/4 are bug-for-bug compatible with this too! ... But David wouldn't leave us there.. he also has a workaround. Sharing the code for a simple Silverlight 4 REST-based cloud-oriented file management app for Azure and S3 David Anson had an opportunity to build an app he's wanted to build for a while and shares it with us: Blobstore -- a small, lightweight Silverlight 4 application that acts as a basic front-end for the Windows Azure Simple Data Storage and the Amazon Simple Storage Service (S3) -- and remember I said he shared the source :) Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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  • Java Resources for Windows Azure

    - by BuckWoody
    Windows Azure is a Platform as a Service – a PaaS – that runs code you write. That code doesn’t just mean the languages on the .NET platform – you can run code from multiple languages, including Java. In fact, you can develop for Windows and SQL Azure using not only Visual Studio but the Eclipse Integrated Development Environment (IDE) as well.  Although not an exhaustive list, here are several links that deal with Java and Windows Azure: Resource Link Windows Azure Java Development Center http://www.windowsazure.com/en-us/develop/java/  Java Development Guidance http://msdn.microsoft.com/en-us/library/hh690943(VS.103).aspx  Running a Java Environment on Windows Azure http://blogs.technet.com/b/port25/archive/2010/10/28/running-a-java-environment-on-windows-azure.aspx  Running a Java Environment on Windows Azure http://blogs.technet.com/b/port25/archive/2010/10/28/running-a-java-environment-on-windows-azure.aspx  Run Java with Jetty in Windows Azure http://blogs.msdn.com/b/dachou/archive/2010/03/21/run-java-with-jetty-in-windows-azure.aspx  Using the plugin for Eclipse http://blogs.msdn.com/b/craig/archive/2011/03/22/new-plugin-for-eclipse-to-get-java-developers-off-the-ground-with-windows-azure.aspx  Run Java with GlassFish in Windows Azure http://blogs.msdn.com/b/dachou/archive/2011/01/17/run-java-with-glassfish-in-windows-azure.aspx  Improving experience for Java developers with Windows  Azure http://blogs.msdn.com/b/interoperability/archive/2011/02/23/improving-experience-for-java-developers-with-windows-azure.aspx  Java Access to SQL Azure via the JDBC Driver for SQL  Server http://blogs.msdn.com/b/brian_swan/archive/2011/03/29/java-access-to-sql-azure-via-the-jdbc-driver-for-sql-server.aspx  How to Get Started with Java, Tomcat on Windows Azure http://blogs.msdn.com/b/usisvde/archive/2011/03/04/how-to-get-started-with-java-tomcat-on-windows-azure.aspx  Deploying Java Applications in Azure http://blogs.msdn.com/b/mariok/archive/2011/01/05/deploying-java-applications-in-azure.aspx  Using the Windows Azure Storage Explorer in Eclipse http://blogs.msdn.com/b/brian_swan/archive/2011/01/11/using-the-windows-azure-storage-explorer-in-eclipse.aspx  Windows Azure Tomcat Solution Accelerator http://archive.msdn.microsoft.com/winazuretomcat  Deploying a Java application to Windows Azure with  Command-line Ant http://java.interoperabilitybridges.com/articles/deploying-a-java-application-to-windows-azure-with-command-line-ant  Video: Open in the Cloud: Windows Azure and Java http://channel9.msdn.com/Events/PDC/PDC10/CS10  AzureRunMe  http://azurerunme.codeplex.com/  Windows Azure SDK for Java http://www.interoperabilitybridges.com/projects/windows-azure-sdk-for-java  AppFabric SDK for Java http://www.interoperabilitybridges.com/projects/azure-java-sdk-for-net-services  Information Cards for Java http://www.interoperabilitybridges.com/projects/information-card-for-java  Apache Stonehenge http://www.interoperabilitybridges.com/projects/apache-stonehenge  Channel 9 Case Study on Java and Windows Azure http://www.microsoft.com/casestudies/Windows-Azure/Gigaspaces/Solution-Provider-Streamlines-Java-Application-Deployment-in-the-Cloud/400000000081   

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  • Performance Optimization &ndash; It Is Faster When You Can Measure It

    - by Alois Kraus
    Performance optimization in bigger systems is hard because the measured numbers can vary greatly depending on the measurement method of your choice. To measure execution timing of specific methods in your application you usually use Time Measurement Method Potential Pitfalls Stopwatch Most accurate method on recent processors. Internally it uses the RDTSC instruction. Since the counter is processor specific you can get greatly different values when your thread is scheduled to another core or the core goes into a power saving mode. But things do change luckily: Intel's Designer's vol3b, section 16.11.1 "16.11.1 Invariant TSC The time stamp counter in newer processors may support an enhancement, referred to as invariant TSC. Processor's support for invariant TSC is indicated by CPUID.80000007H:EDX[8]. The invariant TSC will run at a constant rate in all ACPI P-, C-. and T-states. This is the architectural behavior moving forward. On processors with invariant TSC support, the OS may use the TSC for wall clock timer services (instead of ACPI or HPET timers). TSC reads are much more efficient and do not incur the overhead associated with a ring transition or access to a platform resource." DateTime.Now Good but it has only a resolution of 16ms which can be not enough if you want more accuracy.   Reporting Method Potential Pitfalls Console.WriteLine Ok if not called too often. Debug.Print Are you really measuring performance with Debug Builds? Shame on you. Trace.WriteLine Better but you need to plug in some good output listener like a trace file. But be aware that the first time you call this method it will read your app.config and deserialize your system.diagnostics section which does also take time.   In general it is a good idea to use some tracing library which does measure the timing for you and you only need to decorate some methods with tracing so you can later verify if something has changed for the better or worse. In my previous article I did compare measuring performance with quantum mechanics. This analogy does work surprising well. When you measure a quantum system there is a lower limit how accurately you can measure something. The Heisenberg uncertainty relation does tell us that you cannot measure of a quantum system the impulse and location of a particle at the same time with infinite accuracy. For programmers the two variables are execution time and memory allocations. If you try to measure the timings of all methods in your application you will need to store them somewhere. The fastest storage space besides the CPU cache is the memory. But if your timing values do consume all available memory there is no memory left for the actual application to run. On the other hand if you try to record all memory allocations of your application you will also need to store the data somewhere. This will cost you memory and execution time. These constraints are always there and regardless how good the marketing of tool vendors for performance and memory profilers are: Any measurement will disturb the system in a non predictable way. Commercial tool vendors will tell you they do calculate this overhead and subtract it from the measured values to give you the most accurate values but in reality it is not entirely true. After falling into the trap to trust the profiler timings several times I have got into the habit to Measure with a profiler to get an idea where potential bottlenecks are. Measure again with tracing only the specific methods to check if this method is really worth optimizing. Optimize it Measure again. Be surprised that your optimization has made things worse. Think harder Implement something that really works. Measure again Finished! - Or look for the next bottleneck. Recently I have looked into issues with serialization performance. For serialization DataContractSerializer was used and I was not sure if XML is really the most optimal wire format. After looking around I have found protobuf-net which uses Googles Protocol Buffer format which is a compact binary serialization format. What is good for Google should be good for us. A small sample app to check out performance was a matter of minutes: using ProtoBuf; using System; using System.Diagnostics; using System.IO; using System.Reflection; using System.Runtime.Serialization; [DataContract, Serializable] class Data { [DataMember(Order=1)] public int IntValue { get; set; } [DataMember(Order = 2)] public string StringValue { get; set; } [DataMember(Order = 3)] public bool IsActivated { get; set; } [DataMember(Order = 4)] public BindingFlags Flags { get; set; } } class Program { static MemoryStream _Stream = new MemoryStream(); static MemoryStream Stream { get { _Stream.Position = 0; _Stream.SetLength(0); return _Stream; } } static void Main(string[] args) { DataContractSerializer ser = new DataContractSerializer(typeof(Data)); Data data = new Data { IntValue = 100, IsActivated = true, StringValue = "Hi this is a small string value to check if serialization does work as expected" }; var sw = Stopwatch.StartNew(); int Runs = 1000 * 1000; for (int i = 0; i < Runs; i++) { //ser.WriteObject(Stream, data); Serializer.Serialize<Data>(Stream, data); } sw.Stop(); Console.WriteLine("Did take {0:N0}ms for {1:N0} objects", sw.Elapsed.TotalMilliseconds, Runs); Console.ReadLine(); } } The results are indeed promising: Serializer Time in ms N objects protobuf-net   807 1000000 DataContract 4402 1000000 Nearly a factor 5 faster and a much more compact wire format. Lets use it! After switching over to protbuf-net the transfered wire data has dropped by a factor two (good) and the performance has worsened by nearly a factor two. How is that possible? We have measured it? Protobuf-net is much faster! As it turns out protobuf-net is faster but it has a cost: For the first time a type is de/serialized it does use some very smart code-gen which does not come for free. Lets try to measure this one by setting of our performance test app the Runs value not to one million but to 1. Serializer Time in ms N objects protobuf-net 85 1 DataContract 24 1 The code-gen overhead is significant and can take up to 200ms for more complex types. The break even point where the code-gen cost is amortized by its faster serialization performance is (assuming small objects) somewhere between 20.000-40.000 serialized objects. As it turned out my specific scenario involved about 100 types and 1000 serializations in total. That explains why the good old DataContractSerializer is not so easy to take out of business. The final approach I ended up was to reduce the number of types and to serialize primitive types via BinaryWriter directly which turned out to be a pretty good alternative. It sounded good until I measured again and found that my optimizations so far do not help much. After looking more deeper at the profiling data I did found that one of the 1000 calls did take 50% of the time. So how do I find out which call it was? Normal profilers do fail short at this discipline. A (totally undeserved) relatively unknown profiler is SpeedTrace which does unlike normal profilers create traces of your applications by instrumenting your IL code at runtime. This way you can look at the full call stack of the one slow serializer call to find out if this stack was something special. Unfortunately the call stack showed nothing special. But luckily I have my own tracing as well and I could see that the slow serializer call did happen during the serialization of a bool value. When you encounter after much analysis something unreasonable you cannot explain it then the chances are good that your thread was suspended by the garbage collector. If there is a problem with excessive GCs remains to be investigated but so far the serialization performance seems to be mostly ok.  When you do profile a complex system with many interconnected processes you can never be sure that the timings you just did measure are accurate at all. Some process might be hitting the disc slowing things down for all other processes for some seconds as well. There is a big difference between warm and cold startup. If you restart all processes you can basically forget the first run because of the OS disc cache, JIT and GCs make the measured timings very flexible. When you are in need of a random number generator you should measure cold startup times of a sufficiently complex system. After the first run you can try again getting different and much lower numbers. Now try again at least two times to get some feeling how stable the numbers are. Oh and try to do the same thing the next day. It might be that the bottleneck you found yesterday is gone today. Thanks to GC and other random stuff it can become pretty hard to find stuff worth optimizing if no big bottlenecks except bloatloads of code are left anymore. When I have found a spot worth optimizing I do make the code changes and do measure again to check if something has changed. If it has got slower and I am certain that my change should have made it faster I can blame the GC again. The thing is that if you optimize stuff and you allocate less objects the GC times will shift to some other location. If you are unlucky it will make your faster working code slower because you see now GCs at times where none were before. This is where the stuff does get really tricky. A safe escape hatch is to create a repro of the slow code in an isolated application so you can change things fast in a reliable manner. Then the normal profilers do also start working again. As Vance Morrison does point out it is much more complex to profile a system against the wall clock compared to optimize for CPU time. The reason is that for wall clock time analysis you need to understand how your system does work and which threads (if you have not one but perhaps 20) are causing a visible delay to the end user and which threads can wait a long time without affecting the user experience at all. Next time: Commercial profiler shootout.

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  • Speaking at DevReach

    - by Sahil Malik
    Ad:: SharePoint 2007 Training in .NET 3.5 technologies (more information). Next week, I will be speaking at Devreach on the following topics - Authoring custom WCF services in SharePoint Sahil Malik, Level 400 We live in a different world today! Gone are the times when you built your webparts around postbacks! Welcome silverlight, jquery, bing maps, google maps, and many others! And there are many enhancements in SharePoint 2010 that let you build such applications, the question is which is right for you? In this session Sahil compares WCF REST Services in SharePoint, The client object model, and custom WCF services, and then dives deep into the WCF aspects of SharePoint. All code, very few slides!   Scalability and Performance of SharePoint 2010 Sahil Malik, Level 400 If there is a topic that has more misinformation than anything else, it has to be the scalability and performance aspects of SharePoint. Did you know, SharePoint 2010 has some real world, under the covers improvement that help it perform and scale better? This session involves taking a deep look under the covers into the specific improvements Microsoft has made between SharePoint 2007 and SharePoint 2010 that truly qualifies SharePoint 2010 as an enterprise scalable product. This doesn't mean the product doesn't have limits - but this session is a lot more than just limits written on a powerpoint slide. This presentation is a true under the scenes look at specific improvements!   Devreach is a premier conference, check out their very impressive speaker and sessions line up. Comment on the article ....

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  • WCI Analytics Installation / Configuration Support Webinar

    - by brian.harrison
    Based on the success of the OAM / WCI integration webinar, the second in our series of Technical Support "brown bag" webinars will be delivered on Tuesday, March 30 at 8AM Pacific Daylight Time. Please review the details below, if you would like to attend the webinar, please take a moment to send an email to the address provided for registration and you will be enrolled in the meeting. What are the best practices for installing and configuring Analytics for the WebCenter Interaction (formerly "ALUI") Portal Application? What are some of the most common failures that occur in this implementation and what can be done to correct these common issues? What are the most common reasons for the tables to be "empty" when I try to produce utilization reports? These are just some of the main areas that will be covered in this one hour webinar which will demonstrate the WCI Analytics installation and configuration in action. Our demonstration will focus on areas where Technical Support sees the largest numbers of customer questions become support incidents in an effort to help avoid the need to create an incident to get the implementation working properly in the customer environment. We will demonstrate the most recent version of WCI Analytics (10.3.0.1) for this presentation, but naturally specific issues known to specific versions will be covered as well. Please join us for what we know will be a valuable and relevant learning session. If you would like to attend this session please send an email to [email protected] indicating your interest, and we will respond to you with a meeting invitation including all of the required access information.

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