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• Java threads not working correctly with linkedlist

  - by user69514

  Hi I am working on the sleeping barber problem. with the addition of having priority customer when they arrive they go in the front of the line and they are the next ones to get a haircut. I'm using a linkedlist and if I see a priority customer I put him in the beginning of the list, if the customer is not priority he goes to the end of the list. then I call the wantHaircut method getting the first element of the list. my problem is that the customer are being processed in the order they arrive, and the priority customer have to wait. here is the code where it all happens. any ideas what I am doing wrong? thanks public void arrivedBarbershop(Customer c){ if(waiting < numChairs && c.isPriority()){ System.out.println("Customer " + c.getID() + ": is a priority customer - SITTING -"); mutex.up(); customer_list.addFirst(c); } else if(waiting >= numChairs && c.isPriority()){ System.out.println("Customer " + c.getID() + ": is a priority customer - STANDING -"); mutex.up(); customer_list.addFirst(c); } else if(waiting < numChairs && !c.isPriority()){ waiting++; System.out.println("Customer " + c.getID() + ": arrived, sitting in the waiting room"); customer_list.addLast(c); customers.up(); // increment waiting customers } else if(waiting >= numChairs && !c.isPriority()) { System.out.println("Customer " + c.getID() + ": went to another barber because waiting room was full - " + waiting + " waiting"); mutex.up(); } if(!customer_list.isEmpty()){ this.wantHairCut(customer_list.removeFirst()); } } public void wantHairCut(Customer c) { mutex.up(); barber.down(); // waits for being allowed in barber chair System.out.println("Customer " + c.getID() + ": getting haircut"); try { /** haircut takes between 1 and 2 seconds **/ Thread.sleep(Barbershop.randomInt(1, 2) * 1000); } catch (InterruptedException e) { } System.out.println("Barber: finished cutting customer " + c.getID() + "'s hair"); c.gotHaircut = true; cutting.up(); // signals cutting has finished /** customer must pay now **/ this.wantToCashout(c); }

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• Wake up thread blocked on accept() call

  - by selbie

  Sockets on Linux question I have a worker thread that is blocked on an accept() call. It simply waits for an incoming network connection, handles it, and then returns to listening for the next connection. When it is time for the program to exit, how do I signal this network worker thread (from the main thread) to return from the accept() call while still being able to gracefully exit its loop and handle it's cleanup code. Some things I tried: 1. pthread_kill to send a signal. Feels kludgy to do this, plus it doesn't reliably allow the thread to do it's shutdown logic. Also makes the program terminate as well. I'd like to avoid signals if at all possible. pthread_cancel. Same as above. It's a harsh kill on the thread. That, and the thread may be doing something else. Closing the listen socket from the main thread in order to make accept() abort. This doesn't reliably work. Some constraints: If the solution involves making the listen socket non-blocking, that is fine. But I don't want to accept a solution that involves the thread waking up via a select call every few seconds to check the exit condition. The thread condition to exit may not be tied to the process exiting. Essentially, the logic I am going for looks like this. void* WorkerThread(void* args) { DoSomeImportantInitialization(); // initialize listen socket and some thread specific stuff while (HasExitConditionBeenSet()==false) { listensize = sizeof(listenaddr); int sock = accept(listensocket, &listenaddr, &listensize); // check if exit condition has been set using thread safe semantics if (HasExitConditionBeenSet()) { break; } if (sock < 0) { printf("accept returned %d (errno==%d)\n", sock, errno); } else { HandleNewNetworkCondition(sock, &listenaddr); } } DoSomeImportantCleanup(); // close listen socket, close connections, cleanup etc.. return NULL; } void SignalHandler(int sig) { printf("Caught CTRL-C\n"); } void NotifyWorkerThreadToExit(pthread_t thread_handle) { // signal thread to exit } int main() { void* ptr_ret= NULL; pthread_t workerthread_handle = 0; pthread_create(&workerthread, NULL, WorkerThread, NULL); signal(SIGINT, SignalHandler); sleep((unsigned int)-1); // sleep until the user hits ctrl-c printf("Returned from sleep call...\n"); SetThreadExitCondition(); // sets global variable with barrier that worker thread checks on // this is the function I'm stalled on writing NotifyWorkerThreadToExit(workerthread_handle); // wait for thread to exit cleanly pthread_join(workerthread_handle, &ptr_ret); DoProcessCleanupStuff(); }

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• Calling a webservice synchronously from a Silverlight 3 application?

  - by Lasse V. Karlsen

  I am trying to reuse some .NET code that performs some calls to a data-access-layer type service. I have managed to package up both the input to the method and the output from the method, but unfortunately the service is called from inside code that I really don't want to rewrite in order to be asynchronous. Unfortunately, the webservice code generated in Silverlight only produces asynchronous methods, so I was wondering if anyone had working code that managed to work around this? I tried the recipe found here: The Easy Way To Synchronously Call WCF Services In Silverlight, but unfortunately it times out and never completes the call. Or rather, what seems to happen is that the completed event handler is called, but only after the method returns. I am suspecting that the event handler is called from a dispatcher or similar, and since I'm blocking the main thread here, it never completes until the code is actually back into the GUI loop. Or something like that. Here's my own version that I wrote before I found the above recipe, but it suffers from the same problem: public static object ExecuteRequestOnServer(Type dalInterfaceType, string methodName, object[] arguments) { string securityToken = "DUMMYTOKEN"; string input = "DUMMYINPUT"; object result = null; Exception resultException = null; object evtLock = new object(); var evt = new System.Threading.ManualResetEvent(false); try { var client = new MinGatServices.DataAccessLayerServiceSoapClient(); client.ExecuteRequestCompleted += (s, e) => { resultException = e.Error; result = e.Result; lock (evtLock) { if (evt != null) evt.Set(); } }; client.ExecuteRequestAsync(securityToken, input); try { var didComplete = evt.WaitOne(10000); if (!didComplete) throw new TimeoutException("A data access layer web service request timed out (" + dalInterfaceType.Name + "." + methodName + ")"); } finally { client.CloseAsync(); } } finally { lock (evtLock) { evt.Close(); evt = null; } } if (resultException != null) throw resultException; else return result; } Basically, both recipes does this: Set up a ManualResetEvent Hook into the Completed event The event handler grabs the result from the service call, and signals the event The main thread now starts the web service call asynchronously It then waits for the event to become signalled However, the event handler is not called until the method above has returned, hence my code that checks for evt != null and such, to avoid TargetInvocationException from killing my program after the method has timed out. Does anyone know: ... if it is possible at all in Silverlight 3 ... what I have done wrong above?

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• How do i return integers from a string ?

  - by kannan.ambadi

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Suppose you are passing a string(for e.g.: “My name has 1 K, 2 A and 3 N”)  which may contain integers, letters or special characters. I want to retrieve only numbers from the input string. We can implement it in many ways such as splitting the string into an array or by using TryParse method. I would like to share another idea, that’s by using Regular expressions. All you have to do is, create an instance of Regular Expression with a specified pattern for integer. Regular expression class defines a method called Split, which splits the specified input string based on the pattern provided during object initialization.     We can write the code as given below:   public static int[] SplitIdSeqenceValues(object combinedArgs)         {             var _argsSeperator = new Regex(@"\D+", RegexOptions.Compiled);               string[] splitedIntegers = _argsSeperator.Split(combinedArgs.ToString());               var args = new int[splitedIntegers.Length];               for (int i = 0; i < splitedIntegers.Length; i++)                 args[i] = MakeSafe.ToSafeInt32(splitedIntegers[i]);                           return args;         }    It would be better, if we set to RegexOptions.Compiled so that the regular expression will have performance boost by faster compilation.   Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Happy Programming  :))   

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• Developer’s Life – Summary of Superhero Articles

  - by Pinal Dave

  Earlier this year, I wrote an article series where I talked about developer’s life and compared it with Superhero. I have got amazing response to this series and I have been receiving quite a lots of email suggesting that I should write more blog post about them. Currently I am not planning to write more blog post but I will soon continue another series. In this blog post, I have summarized the entire series. Let me know if you want me to write about any superhero. I will see what I can do about that hero. Developer’s Life – Every Developer is a Captain America Captain America was first created as a comic book character in the 1940’s as a way to boost morale during World War II.  Aimed at a children’s audience, his legacy faded away when the war ended.  However, he has recently has a major reboot to become a popular movie character that deals with modern issues. Developer’s Life – Every Developer is the Incredible Hulk The Incredible Hulk is possibly one of the scariest superheroes out there.  All superheroes are meant to be “out of this world” and awe-inspiring, but I think most people will agree with I say The Hulk takes this to the next level.  He is the result of an industrial accident, which is scary enough in it’s own right.  Plus, when mild-mannered Bruce Banner is angered, he goes completely out-of-control and transforms into a destructive monster that he cannot control and has no memories of. Developer’s Life – Every Developer is a Wonder Woman We have focused a lot lately on this “superhero series.”  I love fantasy books and movies, and I feel like there is a lot to be learned from them.  As I am writing this series, though, I have noticed that every super hero I write about is a man.  So today, I would like to talk about the major female super hero – Wonder Woman. Developer’s Life – Every Developer is a Harry Potter Harry Potter might not be a superhero in the traditional sense, but I believe he still has a lot to teach us and show us about life as a developer.  If you have been living under a rock for the last 17 years, you might not know that Harry Potter is the main character in an extremely popular series of books and movies documenting the education and tribulation of a young wizard (and his friends). Developer’s Life – Every Developer is Like Transformers Transformers may not be superheroes – they don’t wear capes, they don’t have amazing powers outside of their size and folding ability, they’re not even human (technically).  Part of their enduring popularity is that while we are enjoying over-the-top movies, we are learning about good leadership and strong personal skills. Developer’s Life – Every Developer is a Iron Man Iron Man is another superhero who is not naturally “super,” but relies on his brain (and money) to turn him into a fighting machine.  While traditional superheroes are still popular, a three-movie franchise and incorporation into the new Avengers series shows that Iron Man is popular enough on his own. Developer’s Life – Every Developer is a Sherlock Holmes I have been thinking a lot about how developers are like super heroes, and I have written two blog posts now comparing them to Spiderman and Superman.  I have a lot of love and respect for developers, and I hope that they are enjoying these articles, and others are learning a little bit about the profession.  There is another fictional character who, while not technically asuper hero, is very powerful, and I also think stands as a good example of a developer. That character is Sherlock Holmes.  Sherlock Holmes is a British detective, first made popular at the turn of the 19thcentury by author Sir Arthur Conan Doyle.  The original Sherlock Holmes was a brilliant detective who could solve the most mind-boggling crime through simple observations and deduction. Developer’s Life – Every Developer is a Chhota Bheem Chhota Bheem is a cartoon character that is extremely popular where I live.  He is my daughter’s favorite characters.  I like to say that children love Chhota Bheem more than their parents – it is lucky for us he is not real!  Children love Chhota Bheem because he is the absolute “good guy.”  He is smart, loyal, and strong.  He and his friends live in Dholakpur and fight off their many enemies – and always win – in every episode.  In each episode, they learn something about friendship, bravery, and being kind to others.  Chhota Bheem is a good role model for children, and I think that he is a good role model for developers are well. Developer’s Life – Every Developer is a Batman Batman is one of the darkest superheroes in the fantasy canon.  He does not come to his powers through any sort of magical coincidence or radioactive insect, but through a lot of psychological scarring caused by witnessing the death of his parents.  Despite his dark back story, he possesses a lot of admirable abilities that I feel bear comparison to developers. Developer’s Life – Every Developer is a Superman I enjoyed comparing developers to Spiderman so much, that I have decided to continue the trend and encourage some of my favorite people (developers) with another favorite superhero – Superman.  Superman is probably the most famous superhero – and one of the most inspiring. Developer’s Life – Every Developer is a Spiderman I have to admit, Spiderman is my favorite superhero.  The most recent movie recently was released in theaters, so it has been at the front of my mind for some time. Spiderman was my favorite superhero even before the latest movie came out, but of course I took my whole family to see the movie as soon as I could!  Every one of us loved it, including my daughter.  We all left the movie thinking how great it would be to be Spiderman.  So, with that in mind, I started thinking about how we are like Spiderman in our everyday lives, especially developers. I would like to know which Superhero is your favorite hero! Reference: Pinal Dave (http://blog.SQLAuthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: Developer, Superhero

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• Commercial Drupal Modules & Themes

  - by Ravish

  A discussion at Drupal.org forums prompted me to give my input about commercial ecosystem around Open Source Content Management Systems. WordPress and Joomla have been growing rapidly since past few years. But, growth rate of Drupal seems to be almost flat. Despite being the most powerful CMS around, Drupal is still not being adopted by masses. Many people will argue that Drupal is not targeted towards masses, but developers. I agree, Drupal is more of a development platform than a consumer CMS. Drupal is ‘many things to many people’, and I can build almost any type of website with it. Drupal is being used for building blogs, corporate websites, Intranet portals, social networking and even a project management system. Looking at the wide array of Drupal implementations, it deserves to be the most widely adopted CMS. I believe there are few challenges that Drupal community needs to overcome. To understand these challenges, I surveyed some webmasters who use Joomla or WordPress but not Drupal. I asked them why they don’t want to use Drupal, following are the responses I got from them: Drupal is too complicated, takes time to learn. Drupal is great, but its admin panel is overwhelming. I couldn’t find any nice themes for Drupal. There is no WYSIWYG editor in Drupal. Most Drupal modules do not work out of the box. There aren’t enough modules like Ubercart which provides any out of the box functionality. I tried modules like CCK, Views and Panels. After wasting several hours struggling with them, I decided to give up on Drupal. I don’t use Drupal because of pushbutton and Garland theme. I had hard time trying to customize Garland and it messed up the whole layout. There are no premium modules and themes for Drupal. Joomla has tons of awesome themes and modules. I don’t want a million hacks like CCK, Views, Tokens, Pathauto, ImageCache and CTools just to run a simple website. Most of the complaints from users are related to the learning and development curve involved with Drupal, and the lack of ecosystem. While most of the problems will be gone in Drupal 7, ecosystem is something that needs to be built by the Drupal community. Drupal distributions are a great step forward. There are few awesome Drupal distributions available like Open Publish, Open Atrium and Drupal Commons. I predict, there will be a wave of many powerful Drupal distributions after Drupal 7 release. Many of them will be user-friendly and commercial supported. Following is my post at Drupal.org forums: Quote from: http://drupal.org/node/863776#comment-3313836 Brian Gardner (StudioPress) and Woo Themes launched premium WordPress themes in 2007, the developer community did not accept it at first. Moreover, they were not even GPL licensed. There was an outcry in WordPress community against them. Following that, most premium theme providers switched to GPL licensing. Despite controversies, users voted for premium theme and plugins by buying them. Inspired by their success, hundreds of other developers started to sell premium themes and plugins. It is now the acceptable and in fact most popular business model among WordPress community. Matt Mullenweg once told me, they would not support premium themes. If he supported, developers would no more give out free GPL themes & plugins. He pointed me towards Joomla, there were hardly any nice free themes & modules available. Now two years forward, premium products are not just accepted but embraced by the WordPress community – http://wordpress.org/extend/themes/commercial/ The quality and number of themes & modules has increased, even the free ones. This also helped to boost the adoption and ecosystem of WordPress. Today, state of Drupal is like WordPress was in 2007. There are hardly any out of the box solutions available for Drupal. Ubercart, Open Publish and Open Atrium are the only ones I can think of. Many of the popular Drupal modules are patches and hole-fillers. Thankfully, these hole-filler modules are going to be in Drupal 7 core. Drupal 7 and distributions will spawn a new array of solutions built upon Drupal. Soon, we will have more like Ubercarts and Open Atriums. If commercial solutions can help fuel this ecosystem and growth, Drupal community will accept them eventually. This debate will not stop your customers from buying your product. If your product is awesome, they will vote for you by buying your product.

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• Information Indepth Newsletter - Linux Edition

  - by Paulo Folgado

  INFORMATION INDEPTH NEWSLETTERLinux Edition February 2011 Stay Connected:  NEWS Now Available: Oracle Linux 6 Get the latest release of Oracle Linux 6, which includes Unbreakable Enterprise Kernel.Download Oracle Linux 6 Read More Customers Succeed by Using Oracle Exadata with Oracle Linux Watch IT executives from Bank of America, Linkshare, and Johns Hopkins as they talk about the business challenges they faced and why they chose to use Oracle Linux along with Oracle Exadata as the solution. Watch Now Video Interview: Oracle Senior Vice President Wim Coekaerts Watch Wim Coekaerts, senior vice president, Linux and Virtualization Engineering, as he talks about use cases for Oracle VM Templates as well as the Unbreakable Enterprise Kernel for Linux.Watch Now Hot Off the Press: Migrate Your IBM AIX Environment to Oracle Linux This new white paper provides recommendations for planning and implementing the migration of applications from an IBM Power System running AIX to Oracle's Sun Fire X4800 Server with Intel Xeon 7560 Processor running Oracle Linux 5.5.Read More  Back to Top BLOGOSPHERE Just Launched: The Oracle Linux Blog Follow our new Oracle Linux blog  to hear the latest updates, product news, upcoming events, and all the latest happenings, directly from the Linux team at Oracle. Back to Top TECH DIVE NEW: Linux/Oracle Solaris CommandComparo Site from Oracle Technology NetworkThis site gives equivalent command syntax in Oracle Solaris 10 and Oracle Enterprise Linux 5 for common administrative tasks--focusing particularly on tasks that have tricky syntax or that you frequently need to double check. It acts as a quick reference for administrators who operate in these two OS environments. Free Download: Oracle Linux Release 5.6Did you know that by using Oracle Linux 5.5 or 5.6 along with the Unbreakable Enterprise Kernel, you can get all the benefits of Linux mainline kernel 2.6.32 and more, right now, without the need to reinstall or migrate to a new operating system such as RHEL6?Read Release NotesDownload Oracle Linux 5.6 LSB 4.0 Certification Completed for Oracle Linux 5.5Oracle Linux 5.5 with Unbreakable Enterprise Kernel successfully completed the LSB 4.0 certification.  Back to Top WEBCASTS Boost Your Linux Performance with Oracle's Enhancements in Infiniband and RDSRegister to hear Director of Kernel Engineering Chris Mason cover scalability and performance improvements in Linux environment. Get the Facts Oracle's Unbreakable Enterprise KernelSVP Wim Coekaerts and Senior Director Monica Kumar cover the facts about and benefits of using Unbreakable Enterprise Kernel.  View Other Webcasts on Demand   Back to Top EVENTS Collaborate 2011April 10-14 Orlando, Florida Cloud Summit Events, WorldwideVarious dates (check the city for date/time of event) Datacenter Efficiency Events WorldwideThese events include Linux and Oracle VM sessions.Various dates (check the city for date/time of event) Virtualization Events in North America Find an Oracle Event  Back to Top EDUCATION Get Oracle Linux Certified from Oracle University Oracle University offers courses in both Oracle Linux and the administration of Oracle Database on Linux.  Back to Top CUSTOMER SPOTLIGHT Pella Corporation Improves IT Performance and Efficiency with Oracle Linux and Oracle VM To improve IT performance and efficiency and lower operational costs, Pella Corporation, has standardized on Oracle VM and Oracle Linux. Read More Disney Store Deploys POS in 330 Stores and 7 Countries on Oracle Linux Disney Store is running 1,500 registers worldwide on a broad Oracle technology software stack including Oracle Database 11g, Oracle Fusion Middleware, and Oracle Linux. Read More Back to Top PARTNER SPOTLIGHT Emulex and Oracle Announce Data Integrity Features The Unbreakable Enterprise Kernel provides data integrity checking between Oracle Database applications and Emulex 8Gb/s LightPulse Fibre Channel Host Bus Adapters. Read More Dell Inc. Dell Inc. tested and validated configurations support Oracle Linux. Back to Top STAY IN TOUCH Follow @ORCL_Linux on Twitter for the latest penguin tweets Bookmark Oracle.com/Linux Read the Oracle Linux blog Back to Top  Oracle Information InDepth newsletters bring targeted news, articles, customer stories, and special offers to business people who want to find out how to streamline enterprise information management, measure results, improve business processes, and communicate a single truth to their constituents. Please send questions or comments to [email protected]. For answers to questions about subscribing, unsubscribing, and managing your Oracle e-mail communications preferences, please see the Oracle E-Mail Communications page. Copyright © 2011, Oracle Corporation and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. This document is provided for information purposes only, and the contents hereof are subject to change without notice. This document is not warranted to be error-free, nor is it subject to any other warranties or conditions, whether expressed orally or implied in law, including implied warranties and conditions of merchantability or fitness for a particular purpose. We specifically disclaim any liability with respect to this document, and no contractual obligations are formed either directly or indirectly by this document. This document may not be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without our prior written permission. 

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• SQL SERVER – CXPACKET – Parallelism – Usual Solution – Wait Type – Day 6 of 28

  - by pinaldave

  CXPACKET has to be most popular one of all wait stats. I have commonly seen this wait stat as one of the top 5 wait stats in most of the systems with more than one CPU. Books On-Line: Occurs when trying to synchronize the query processor exchange iterator. You may consider lowering the degree of parallelism if contention on this wait type becomes a problem. CXPACKET Explanation: When a parallel operation is created for SQL Query, there are multiple threads for a single query. Each query deals with a different set of the data (or rows). Due to some reasons, one or more of the threads lag behind, creating the CXPACKET Wait Stat. There is an organizer/coordinator thread (thread 0), which takes waits for all the threads to complete and gathers result together to present on the client’s side. The organizer thread has to wait for the all the threads to finish before it can move ahead. The Wait by this organizer thread for slow threads to complete is called CXPACKET wait. Note that not all the CXPACKET wait types are bad. You might experience a case when it totally makes sense. There might also be cases when this is unavoidable. If you remove this particular wait type for any query, then that query may run slower because the parallel operations are disabled for the query. Reducing CXPACKET wait: We cannot discuss about reducing the CXPACKET wait without talking about the server workload type. OLTP: On Pure OLTP system, where the transactions are smaller and queries are not long but very quick usually, set the “Maximum Degree of Parallelism” to 1 (one). This way it makes sure that the query never goes for parallelism and does not incur more engine overhead. EXEC sys.sp_configure N'cost threshold for parallelism', N'1' GO RECONFIGURE WITH OVERRIDE GO Data-warehousing / Reporting server: As queries will be running for long time, it is advised to set the “Maximum Degree of Parallelism” to 0 (zero). This way most of the queries will utilize the parallel processor, and long running queries get a boost in their performance due to multiple processors. EXEC sys.sp_configure N'cost threshold for parallelism', N'0' GO RECONFIGURE WITH OVERRIDE GO Mixed System (OLTP & OLAP): Here is the challenge. The right balance has to be found. I have taken a very simple approach. I set the “Maximum Degree of Parallelism” to 2, which means the query still uses parallelism but only on 2 CPUs. However, I keep the “Cost Threshold for Parallelism” very high. This way, not all the queries will qualify for parallelism but only the query with higher cost will go for parallelism. I have found this to work best for a system that has OLTP queries and also where the reporting server is set up. Here, I am setting ‘Cost Threshold for Parallelism’ to 25 values (which is just for illustration); you can choose any value, and you can find it out by experimenting with the system only. In the following script, I am setting the ‘Max Degree of Parallelism’ to 2, which indicates that the query that will have a higher cost (here, more than 25) will qualify for parallel query to run on 2 CPUs. This implies that regardless of the number of CPUs, the query will select any two CPUs to execute itself. EXEC sys.sp_configure N'cost threshold for parallelism', N'25' GO EXEC sys.sp_configure N'max degree of parallelism', N'2' GO RECONFIGURE WITH OVERRIDE GO Read all the post in the Wait Types and Queue series. Additionally a must read comment of Jonathan Kehayias. Note: The information presented here is from my experience and I no way claim it to be accurate. I suggest you all to read the online book for further clarification. All the discussion of Wait Stats over here is generic and it varies from system to system. It is recommended that you test this on the development server before implementing on the production server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: DMV, Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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• Optimizing collision engine bottleneck

  - by Vittorio Romeo

  Foreword: I'm aware that optimizing this bottleneck is not a necessity - the engine is already very fast. I, however, for fun and educational purposes, would love to find a way to make the engine even faster. I'm creating a general-purpose C++ 2D collision detection/response engine, with an emphasis on flexibility and speed. Here's a very basic diagram of its architecture: Basically, the main class is World, which owns (manages memory) of a ResolverBase*, a SpatialBase* and a vector<Body*>. SpatialBase is a pure virtual class which deals with broad-phase collision detection. ResolverBase is a pure virtual class which deals with collision resolution. The bodies communicate to the World::SpatialBase* with SpatialInfo objects, owned by the bodies themselves. There currenly is one spatial class: Grid : SpatialBase, which is a basic fixed 2D grid. It has it's own info class, GridInfo : SpatialInfo. Here's how its architecture looks: The Grid class owns a 2D array of Cell*. The Cell class contains two collection of (not owned) Body*: a vector<Body*> which contains all the bodies that are in the cell, and a map<int, vector<Body*>> which contains all the bodies that are in the cell, divided in groups. Bodies, in fact, have a groupId int that is used for collision groups. GridInfo objects also contain non-owning pointers to the cells the body is in. As I previously said, the engine is based on groups. Body::getGroups() returns a vector<int> of all the groups the body is part of. Body::getGroupsToCheck() returns a vector<int> of all the groups the body has to check collision against. Bodies can occupy more than a single cell. GridInfo always stores non-owning pointers to the occupied cells. After the bodies move, collision detection happens. We assume that all bodies are axis-aligned bounding boxes. How broad-phase collision detection works: Part 1: spatial info update For each Body body: Top-leftmost occupied cell and bottom-rightmost occupied cells are calculated. If they differ from the previous cells, body.gridInfo.cells is cleared, and filled with all the cells the body occupies (2D for loop from the top-leftmost cell to the bottom-rightmost cell). body is now guaranteed to know what cells it occupies. For a performance boost, it stores a pointer to every map<int, vector<Body*>> of every cell it occupies where the int is a group of body->getGroupsToCheck(). These pointers get stored in gridInfo->queries, which is simply a vector<map<int, vector<Body*>>*>. body is now guaranteed to have a pointer to every vector<Body*> of bodies of groups it needs to check collision against. These pointers are stored in gridInfo->queries. Part 2: actual collision checks For each Body body: body clears and fills a vector<Body*> bodiesToCheck, which contains all the bodies it needs to check against. Duplicates are avoided (bodies can belong to more than one group) by checking if bodiesToCheck already contains the body we're trying to add. const vector<Body*>& GridInfo::getBodiesToCheck() { bodiesToCheck.clear(); for(const auto& q : queries) for(const auto& b : *q) if(!contains(bodiesToCheck, b)) bodiesToCheck.push_back(b); return bodiesToCheck; } The GridInfo::getBodiesToCheck() method IS THE BOTTLENECK. The bodiesToCheck vector must be filled for every body update because bodies could have moved meanwhile. It also needs to prevent duplicate collision checks. The contains function simply checks if the vector already contains a body with std::find. Collision is checked and resolved for every body in bodiesToCheck. That's it. So, I've been trying to optimize this broad-phase collision detection for quite a while now. Every time I try something else than the current architecture/setup, something doesn't go as planned or I make assumption about the simulation that later are proven to be false. My question is: how can I optimize the broad-phase of my collision engine maintaining the grouped bodies approach? Is there some kind of magic C++ optimization that can be applied here? Can the architecture be redesigned in order to allow for more performance? Actual implementation: SSVSCollsion Body.h, Body.cpp World.h, World.cpp Grid.h, Grid.cpp Cell.h, Cell.cpp GridInfo.h, GridInfo.cpp

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• OpenWorld: Spotlight on Fusion CRM

  - by Tony Berk

  Oracle OpenWorld is less than 2 weeks away, so you need to start figuring out how you are going to maximize your week. I don't want to discourage you, but I'm pretty sure it is impossible to attend all 2000+ sessions. So you need to focus on what's important to you. Many of our CRM customers will be interested in Fusion CRM, since they have already started Fusion implementations or determining when to start. If that's you, or you are just looking for an overview of Fusion CRM, we've got you covered! Let's start at the top! For an overview of what is in Fusion CRM and where it is going, you should attend the general session and roadmap session: General Session: Oracle Fusion CRM—Improving Sales Effectiveness, Efficiency, and Ease of Use (Session ID: GEN9674) - Oct 2, 11:45 AM. Anthony Lye, Senior VP, Oracle leads this general session focused on Oracle Fusion CRM. Oracle Fusion CRM optimizes territories, combines quota management and incentive compensation, integrates sales and marketing, and cleanses and enriches data—all within a single application platform. Oracle Fusion can be configured, changed, and extended at runtime by end users, business managers, IT, and developers. Oracle Fusion CRM can be used from the Web, from a smartphone, from Microsoft Outlook, or from an iPad. Deloitte, sponsor of the CRM Track, will also present key concepts on CRM implementations. Oracle Fusion Customer Relationship Management: Overview/Strategy/Customer Experiences/Roadmap (CON9407) - Oct 1, 3:15PM. In this session, learn how Oracle Fusion CRM enables companies to create better sales plans, generate more quality leads, and achieve higher win rates and find out why customers are adopting Oracle Fusion CRM. Gain a deeper understanding of the unique capabilities only Oracle Fusion CRM provides, and learn how Oracle’s commitment to CRM innovation is driving a wide range of future enhancements. There is also a General Session for all Fusion Applications providing insight into the current strategy of the full product line and a high-level roadmap for each product area: Oracle Fusion Applications—Overview, Strategy, and Roadmap (GEN9433) - Oct 1, 10:45AM. This session will be repeated on Oct 3, 10:15AM. Now, if you want to drill down into some more detail, there are a lot more sessions with Oracle product management and customers. I'll highlight a few, but suggest you review the Fusion CRM Focus On document, or the search in the Content Catalog or Session Builder.  Driving Sales Performance with Oracle Fusion CRM (CON9744) - Oct 3, 10:15AM. Demonstrates how sales executives can gain instant visibility into their business, deliver pervasive coaching to their reps, maximize their sales pipeline, and drive team alignment. The result is increased sales performance that enables sales executives to deliver more revenue without increasing their resources or expenses. Maximize Your Revenue Potential with Oracle Fusion CRM Sales Planning (CON9751) - Oct 2, 1:15PM. Learn how Oracle Fusion CRM helps companies intelligently optimize sales planning and manage sales performance including the ability to predict their future sales opportunities and use those predictions in conjunction with past sales data to optimally define their sales territories, sales quotas, and incentive compensation plans. Boost Marketing’s Contribution to Revenue with Oracle Fusion CRM Marketing (CON9746) - Oct 3, 11:45AM. Learn how Oracle Fusion CRM can help your organization integrate sales and marketing, using one CRM platform. See how Oracle Fusion CRM can help your organization learn where to invest its precious marketing dollars; drive more revenue with cross-channel marketing and prospecting capabilities, including and not limited to e-mail, Web, and social media; improve lead conversion with integrated lead management functionality; and do more with less by automating many manual tasks. Oracle Fusion CRM: Social Marketing (CON11559) - Oct 1, 3:15PM. Learn how Oracle’s acquisition of Collective Intellect, Vitrue, and Involver extends Oracle Fusion Marketing as a world-class social marketing solution. Oracle Fusion Social CRM Strategy and Roadmap: Future of Collaboration and Social Engagement (CON9750) - Oct 4, 11:15AM. Hear how Oracle can help you know your customers better, encourage brand affinity, and improve collaboration within your ecosystem. This session reviews Oracle's social media solution and shows how you can discover hidden insights buried in your enterprise and social data. Also learn how Oracle Social Network revolutionizes how enterprise users work, collaborate, and share to achieve successful outcomes. Of course, we recommend you hear from the current Fusion CRM customers too. So, don't miss Oracle Fusion Customer Relationship Management: Customer Adoption and Experiences (CON9415) on Oct 3 at 10:15AM for panel of customers discussing implementation experiences, best practices and benefits.  After listening to all of this great information, you are probably going to have questions. Well, the experts will be on hand to help answer your questions and plan how your organization can get going with Fusion CRM. Be sure to head down to the DEMOgrounds and CRM Pavilion in the Moscone West Exhibit Hall. And finally, there is the always popular Meet the Experts session focused on Fusion CRM (MTE9658) on Oct 2 at 5PM (pre-registration via Schedule Builder is recommended.) In addition, there are more sessions on Mobility, Extensibility, Incentive Compensation, Fusion Customer Hub and other key components of the Fusion Applications infrastructure, Oracle Cloud and much, much more! For a full list, utilize the Fusion CRM Focus On document and Content Catalog. Enjoy!

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• Selling Visual Studio ALM

  - by Tarun Arora

  Introduction As a consultant I have been selling Application Lifecycle Management services using Visual Studio and Team Foundation Server. I’ve been contacted various times by friends working in organization telling me that ALM processes in their company were benchmarked when dinosaurs walked the earth. Most of these individuals already know the great features Microsoft ALM tools offer and are keen to start a conversation with the CIO but don’t exactly know where to start. It is very important how you engage in your first conversation, if you start the conversation with ‘There is this great tooling from Microsoft which offers amazing features to boost developer productivity, … ‘ from experience I can tell you the reply from your CIO would be ‘I already know! Our existing landscape has a combination of bleeding edge open source and cutting edge licensed tools which already cover these features quite well, more over Microsoft products have a high licensing cost associated to them.’ You will always find it harder to sell by feature, the trick is to highlight the gap in the existing processes & tools and then highlight the impact of these gaps to the overall development processes, by now you would have captured enough attention to show off how the ALM tooling offered by Microsoft not only fills those gaps but offers great value adds to take their development practices to the next level. Rangers ALM Assessment Guide Image 1 – Welcome! First look at the Rangers ALM assessment guide Most organization already have some processes in place to cover aspects of ALM. How do you go about proving that there isn’t enough cover in place? This is where Visual Studio ALM Rangers ALM Assessment guide can help. The ALM assessment guide is really a tool that helps you gather information about Development practices and processes within a customer's environment. Several questionnaires are used to identify the current state of individual development lifecycle areas and decide on a desired state for those processes. It also presents guidance and roll-up summaries to help with recommendations moving forward. The ALM Rangers assessment guide can be downloaded from here. Image 2 – ALM Assessment guide divided into different functions of SDLC The assessment guide is divided into different functions of Software Development Lifecycle (listed below), this gives you the ability to access how mature the company is in different areas of SDLC. Architecture & Design Requirement Engineering & UX Development Software Configuration Management Governance Deployment & Operations Testing & Quality Assurance Project Planning & Management Each section has a set of questions, fill in the assessment by selecting “Never/Sometimes/Always” from the Answer column in the question sheets.  Each answer has weightage to the overall score. Each question has a link next to it, clicking the link takes you to the Reference sheet which gives you more details about the question along with a reason for “why you need to ask this question?”, “other ways to phrase the question” and “what to expect as an answer from the customer”. The trick is to engage the customer in a discussion. You need to probe a lot, listen to the customer and have a discussion with several team members, preferably without management to ensure that you receive candid feedback. This reminds me of a funny incident when during an ALM review a customer told me that they have a sophisticated semi-automated application deployment process, further discussions revealed that deployment actually involved 72 manual configuration steps per production node. Such observations can be recorded in the Issue Brainstorming worksheet for further consideration later. It is also worth mentioning the different levels of ALM maturity to the customer. By default the desired state of ALM maturity is set to Standard, it is possible to set a desired state by area, you should strive for Advanced or Dynamic, it always helps by explaining the classification and advantages. Image 3 – ALM levels by description The ALM assessment guide helps you arrive at a quantitative measure of the company’s ALM maturity. The resultant graph plotted on a spider’s web shows you the company’s current state of ALM maturity and the desired state of ALM maturity. Further since the results are classified by area you can immediately spot the areas where the customer needs immediate help. Image 4 – The spiders web! The red cross icons are areas shouting out for immediate attention, the yellow exclamation icons are areas that need improvement. These icons are calculated on the difference between the Current State of ALM maturity VS the Desired state of ALM maturity. Image 5 – Results by area Conclusion To conclude the Rangers ALM assessment guide gives you the ability to, Measure the customer’s current ALM maturity level Understand the ALM maturity level the customer desires to achieve Capture a healthy list of issues the customer wants to brainstorm further Now What’s next…? Download and get started with the Rangers ALM Assessment Guide. If you have successfully captured the above listed three pieces of information you are in a great state to make recommendations on the identified areas highlighting the benefits that Visual Studio ALM tools would offer. In the next post I will be covering how to take the ALM assessment results as the base to actually convert your recommendation into a sell.  Remember to subscribe to http://feeds.feedburner.com/TarunArora. I would love to hear your feedback! If you have any recommendations on things that I should consider or any questions or feedback, feel free to leave a comment. *** A special thanks goes out to fellow ranges Willy, Ethem and Philip for reviewing the blog post and providing valuable feedback. ***

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• problem occur during installation of moses scripts

  - by lenny99

  we got error when compile moses-script. process of it as follows: minakshi@minakshi-Vostro-3500:~/Desktop/monu/moses/scripts$ make release # Compile the parts make all make[1]: Entering directory `/home/minakshi/Desktop/monu/moses/scripts' # Building memscore may fail e.g. if boost is not available. # We ignore this because traditional scoring will still work and memscore isn't used by default. cd training/memscore ; \ ./configure && make \ || ( echo "WARNING: Building memscore failed."; \ echo 'training/memscore/memscore' >> ../../release-exclude ) checking for a BSD-compatible install... /usr/bin/install -c checking whether build environment is sane... yes checking for gawk... no checking for mawk... mawk checking whether make sets $(MAKE)... yes checking for g++... g++ checking whether the C++ compiler works... yes checking for C++ compiler default output file name... a.out checking for suffix of executables... checking whether we are cross compiling... no checking for suffix of object files... o checking whether we are using the GNU C++ compiler... yes checking whether g++ accepts -g... yes checking for style of include used by make... GNU checking dependency style of g++... gcc3 checking for gcc... gcc checking whether we are using the GNU C compiler... yes checking whether gcc accepts -g... yes checking for gcc option to accept ISO C89... none needed checking dependency style of gcc... gcc3 checking for boostlib >= 1.31.0... yes checking for cos in -lm... yes checking for gzopen in -lz... yes checking for cblas_dgemm in -lgslcblas... no checking for gsl_blas_dgemm in -lgsl... no checking how to run the C++ preprocessor... g++ -E checking for grep that handles long lines and -e... /bin/grep checking for egrep... /bin/grep -E checking for ANSI C header files... yes checking for sys/types.h... yes checking for sys/stat.h... yes checking for stdlib.h... yes checking for string.h... yes checking for memory.h... yes checking for strings.h... yes checking for inttypes.h... yes checking for stdint.h... yes checking for unistd.h... yes checking n_gram.h usability... no checking n_gram.h presence... no checking for n_gram.h... no checking for size_t... yes checking for ptrdiff_t... yes configure: creating ./config.status config.status: creating Makefile config.status: creating config.h config.status: config.h is unchanged config.status: executing depfiles commands make[2]: Entering directory `/home/minakshi/Desktop/monu/moses/scripts/training/memscore' make all-am make[3]: Entering directory `/home/minakshi/Desktop/monu/moses/scripts/training/memscore' make[3]: Leaving directory `/home/minakshi/Desktop/monu/moses/scripts/training/memscore' make[2]: Leaving directory `/home/minakshi/Desktop/monu/moses/scripts/training/memscore' touch release-exclude # No files excluded by default pwd=`pwd`; \ for subdir in cmert-0.5 phrase-extract symal mbr lexical-reordering; do \ make -C training/$subdir || exit 1; \ echo "### Compiler $subdir"; \ cd $pwd; \ done make[2]: Entering directory `/home/minakshi/Desktop/monu/moses/scripts/training/cmert-0.5' make[2]: Nothing to be done for `all'. make[2]: Leaving directory `/home/minakshi/Desktop/monu/moses/scripts/training/cmert-0.5' ### Compiler cmert-0.5 make[2]: Entering directory `/home/minakshi/Desktop/monu/moses/scripts/training/phrase-extract' make[2]: Nothing to be done for `all'. make[2]: Leaving directory `/home/minakshi/Desktop/monu/moses/scripts/training/phrase-extract' ### Compiler phrase-extract make[2]: Entering directory `/home/minakshi/Desktop/monu/moses/scripts/training/symal' make[2]: Nothing to be done for `all'. make[2]: Leaving directory `/home/minakshi/Desktop/monu/moses/scripts/training/symal' ### Compiler symal make[2]: Entering directory `/home/minakshi/Desktop/monu/moses/scripts/training/mbr' make[2]: Nothing to be done for `all'. make[2]: Leaving directory `/home/minakshi/Desktop/monu/moses/scripts/training/mbr' ### Compiler mbr make[2]: Entering directory `/home/minakshi/Desktop/monu/moses/scripts/training/lexical-reordering' make[2]: Nothing to be done for `all'. make[2]: Leaving directory `/home/minakshi/Desktop/monu/moses/scripts/training/lexical-reordering' ### Compiler lexical-reordering ## All files that need compilation were compiled make[1]: Leaving directory `/home/minakshi/Desktop/monu/moses/scripts' /bin/sh: ./check-dependencies.pl: not found make: *** [release] Error 127 We don't know why this error occurs? check-dependencies.pl file existed in scripts folder ...

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• Unexpected advantage of Engineered Systems

  - by user12244672

  It's not surprising that Engineered Systems accelerate the debugging and resolution of customer issues. But what has surprised me is just how much faster issue resolution is with Engineered Systems such as SPARC SuperCluster. These are powerful, complex, systems used by customers wanting extreme database performance, app performance, and cost saving server consolidation. A SPARC SuperCluster consists or 2 or 4 powerful T4-4 compute nodes, 3 or 6 extreme performance Exadata Storage Cells, a ZFS Storage Appliance 7320 for general purpose storage, and ultra fast Infiniband switches.  Each with its own firmware. It runs Solaris 11, Solaris 10, 11gR2, LDoms virtualization, and Zones virtualization on the T4-4 compute nodes, a modified version of Solaris 11 in the ZFS Storage Appliance, a modified and highly tuned version of Oracle Linux running Exadata software on the Storage Cells, another Linux derivative in the Infiniband switches, etc. It has an Infiniband data network between the components, a 10Gb data network to the outside world, and a 1Gb management network. And customers can run whatever middleware and apps they want on it, clustered in whatever way they want. In one word, powerful.  In another, complex. The system is highly Engineered.  But it's designed to run general purpose applications. That is, the physical components, configuration, cabling, virtualization technologies, switches, firmware, Operating System versions, network protocols, tunables, etc. are all preset for optimum performance and robustness. That improves the customer experience as what the customer runs leverages our technical know-how and best practices and is what we've tested intensely within Oracle. It should also make debugging easier by fixing a large number of variables which would otherwise be in play if a customer or Systems Integrator had assembled such a complex system themselves from the constituent components.  For example, there's myriad network protocols which could be used with Infiniband.  Myriad ways the components could be interconnected, myriad tunable settings, etc. But what has really surprised me - and I've been working in this area for 15 years now - is just how much easier and faster Engineered Systems have made debugging and issue resolution. All those error opportunities for sub-optimal cabling, unusual network protocols, sub-optimal deployment of virtualization technologies, issues with 3rd party storage, issues with 3rd party multi-pathing products, etc., are simply taken out of the equation. All those error opportunities for making an issue unique to a particular set-up, the "why aren't we seeing this on any other system ?" type questions, the doubts, just go away when we or a customer discover an issue on an Engineered System. It enables a really honed response, getting to the root cause much, much faster than would otherwise be the case. Here's a couple of examples from the last month, one found in-house by my team, one found by a customer: Example 1: We found a node eviction issue running 11gR2 with Solaris 11 SRU 12 under extreme load on what we call our ExaLego test system (mimics an Exadata / SuperCluster 11gR2 Exadata Storage Cell set-up).  We quickly established that an enhancement in SRU12 enabled an 11gR2 process to query Infiniband's Subnet Manager, replacing a fallback mechanism it had used previously.  Under abnormally heavy load, the query could return results which were misinterpreted resulting in node eviction.  In several daily joint debugging sessions between the Solaris, Infiniband, and 11gR2 teams, the issue was fully root caused, evaluated, and a fix agreed upon.  That fix went back into all Solaris releases the following Monday.  From initial issue discovery to the fix being put back into all Solaris releases was just 10 days. Example 2: A customer reported sporadic performance degradation.  The reasons were unclear and the information sparse.  The SPARC SuperCluster Engineered Systems support teams which comprises both SPARC/Solaris and Database/Exadata experts worked to root cause the issue.  A number of contributing factors were discovered, including tunable parameters.  An intense collaborative investigation between the engineering teams identified the root cause to a CPU bound networking thread which was being starved of CPU cycles under extreme load.  Workarounds were identified.  Modifications have been put back into 11gR2 to alleviate the issue and a development project already underway within Solaris has been sped up to provide the final resolution on the Solaris side.  The fixed SPARC SuperCluster configuration greatly aided issue reproduction and dramatically sped up root cause analysis, allowing the correct workarounds and fixes to be identified, prioritized, and implemented.  The customer is now extremely happy with performance and robustness.  Since the configuration is common to other customers, the lessons learned are being proactively rolled out to other customers and incorporated into the installation procedures for future customers.  This effectively acts as a turbo-boost to performance and reliability for all SPARC SuperCluster customers.  If this had occurred in a "home grown" system of this complexity, I expect it would have taken at least 6 months to get to the bottom of the issue.  But because it was an Engineered System, known, understood, and qualified by both the Solaris and Database teams, we were able to collaborate closely to identify cause and effect and expedite a solution for the customer.  That is a key advantage of Engineered Systems which should not be underestimated.  Indeed, the initial issue mitigation on the Database side followed by final fix on the Solaris side, highlights the high degree of collaboration and excellent teamwork between the Oracle engineering teams.  It's a compelling advantage of the integrated Oracle Red Stack in general and Engineered Systems in particular.

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• On Reflector Pricing

  - by Nick Harrison

  I have heard a lot of outrage over Red Gate's decision to charge for Reflector. In the interest of full disclosure, I am a fan of Red Gate. I have worked with them on several usability tests. They also sponsor Simple Talk where I publish articles. They are a good company. I am also a BIG fan of Reflector. I have used it since Lutz originally released it. I have written my own add-ins. I have written code to host reflector and use its object model in my own code. Reflector is a beautiful tool. The care that Lutz took to incorporate extensibility is amazing. I have never had difficulty convincing my fellow developers that it is a wonderful tool. Almost always, once anyone sees it in action, it becomes their favorite tool. This wide spread adoption and usability has made it an icon and pivotal pillar in the DotNet community. Even folks with the attitude that if it did not come out of Redmond then it must not be any good, still love it. It is ironic to hear everyone clamoring for it to be released as open source. Reflector was never open source, it was free, but you never were able to peruse the source code and contribute your own changes. You could not even use Reflector to view the source code. From the very beginning, it was never anyone's intention for just anyone to examine the source code and make their own contributions aside from the add-in model. Lutz chose to hand over the reins to Red Gate because he believed that they would be able to build on his original vision and keep the product viable and effective. He did not choose to make it open source, hoping that the community would be up to the challenge. The simplicity and elegance may well have been lost with the "design by committee" nature of open source. Despite being a wonderful and beloved tool, Reflector cannot be an easy tool to maintain. Maybe because it is so wonderful and beloved, it is even more difficult to maintain. At any rate, we have high expectations. Reflector must continue to be able to reasonably disassemble every language construct that the framework and core languages dream up. We want it to be fast, and we also want it to continue to be simple to use. No small order. Red Gate tried to keep the core product free. Sadly there was not enough interest in the Pro version to subsidize the rest of the expenses. $35 is a reasonable cost, more than reasonable. I have read the blog posts and forum posts complaining about the time associated with getting the expense approved. I have heard people complain about the cost being unreasonable if you are a developer from certain countries. Let's do the math. How much of a productivity boost is Reflector? How many hours do you think it saves you in a typical project? The next question is a little easier if you are a contractor or a consultant, but what is your hourly rate? If you are not a contractor, you can probably figure out an hourly rate. How long does it take to get a return on your investment? The value added proposition is not a difficult one to make. I have read people clamoring that Red Gate sucks and is evil. They complain about broken promises and conflicts of interest. Relax! Red Gate is not evil. The world is not coming to an end. The sun will come up tomorrow. I am sure that Red Gate will come up with options for volume licensing or site licensing for companies that want to get a licensed copy for their entire team. Don't panic, and I am sure that many great improvements are on the horizon. Switching the UI to WPF and including a tabbed interface opens up lots of possibilities.

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• Multiple Audio Issues

  - by Lerp

  I am having issues with my audio on Ubuntu 12.04, I will try and give as much detail as possible so sorry if there's too much detail. The Problem Audio plays from both speakers and headphone regardless of what connector I choose and regardless of the profile I use. The microphone is constantly being played through headphones & speakers. The headphone audio is extremely quiet but plays from both ears when I select "Headphones" for the connector in Sound Settings. The headphone audio only plays from one ear and is quiet (but not as quiet as above) when I select "Analogue Output" for the connector in Sound Settings. I can only select "Headphones" as the connector in Sound Settings if I set the profile to either "Analogue Stereo Output/Duplex", all others only allow me to choose "Analogue Output" for the connector. Despite the headphone sound issues, the speaker sound is fine apart from the fact that I am not able to select which output is used, they just both play. My headphone and microphone are plugged into the front and my speakers are plugged into the back. What I have tried I have put everything in alsamixer to 100 apart from "Front Mic Boost" which I have set to 0. Command Output aplay -l **** List of PLAYBACK Hardware Devices **** card 0: Intel [HDA Intel], device 0: AD198x Analog [AD198x Analog] Subdevices: 0/1 Subdevice #0: subdevice #0 card 0: Intel [HDA Intel], device 1: AD198x Digital [AD198x Digital] Subdevices: 1/1 Subdevice #0: subdevice #0 card 0: Intel [HDA Intel], device 2: AD198x Headphone [AD198x Headphone] Subdevices: 1/1 Subdevice #0: subdevice #0 arecord -l **** List of CAPTURE Hardware Devices **** card 0: Intel [HDA Intel], device 0: AD198x Analog [AD198x Analog] Subdevices: 2/3 Subdevice #0: subdevice #0 Subdevice #1: subdevice #1 Subdevice #2: subdevice #2 cat /proc/asound/cards 0 [Intel ]: HDA-Intel - HDA Intel HDA Intel at 0xf7ff8000 irq 70 cat /proc/asound/modules 0 snd_hda_intel cat /proc/asound/card*/codec* | grep "Codec" Codec: Analog Devices AD1989B cat /etc/modprobe.d/alsa-base.conf # autoloader aliases install sound-slot-0 /sbin/modprobe snd-card-0 install sound-slot-1 /sbin/modprobe snd-card-1 install sound-slot-2 /sbin/modprobe snd-card-2 install sound-slot-3 /sbin/modprobe snd-card-3 install sound-slot-4 /sbin/modprobe snd-card-4 install sound-slot-5 /sbin/modprobe snd-card-5 install sound-slot-6 /sbin/modprobe snd-card-6 install sound-slot-7 /sbin/modprobe snd-card-7 # Cause optional modules to be loaded above generic modules install snd /sbin/modprobe --ignore-install snd $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist snd-ioctl32 ; /sbin/modprobe --quiet --use-blacklist snd-seq ; } # # Workaround at bug #499695 (reverted in Ubuntu see LP #319505) install snd-pcm /sbin/modprobe --ignore-install snd-pcm $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist snd-pcm-oss ; : ; } install snd-mixer /sbin/modprobe --ignore-install snd-mixer $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist snd-mixer-oss ; : ; } install snd-seq /sbin/modprobe --ignore-install snd-seq $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist snd-seq-midi ; /sbin/modprobe --quiet --use-blacklist snd-seq-oss ; : ; } # install snd-rawmidi /sbin/modprobe --ignore-install snd-rawmidi $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist snd-seq-midi ; : ; } # Cause optional modules to be loaded above sound card driver modules install snd-emu10k1 /sbin/modprobe --ignore-install snd-emu10k1 $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist snd-emu10k1-synth ; } install snd-via82xx /sbin/modprobe --ignore-install snd-via82xx $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist snd-seq ; } # Load saa7134-alsa instead of saa7134 (which gets dragged in by it anyway) install saa7134 /sbin/modprobe --ignore-install saa7134 $CMDLINE_OPTS && { /sbin/modprobe --quiet --use-blacklist saa7134-alsa ; : ; } # Prevent abnormal drivers from grabbing index 0 options bt87x index=-2 options cx88_alsa index=-2 options saa7134-alsa index=-2 options snd-atiixp-modem index=-2 options snd-intel8x0m index=-2 options snd-via82xx-modem index=-2 options snd-usb-audio index=-2 options snd-usb-caiaq index=-2 options snd-usb-ua101 index=-2 options snd-usb-us122l index=-2 options snd-usb-usx2y index=-2 # Ubuntu #62691, enable MPU for snd-cmipci options snd-cmipci mpu_port=0x330 fm_port=0x388 # Keep snd-pcsp from being loaded as first soundcard options snd-pcsp index=-2 # Keep snd-usb-audio from beeing loaded as first soundcard options snd-usb-audio index=-2 Hopefully I have provided enough information, I will happily provide anymore information needed. Thank you. Update Reinstalling alsa-base and pulseaudio fixed the headphone issues I was having.

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• A Patent for Workload Management Based on Service Level Objectives

  - by jsavit

  I'm very pleased to announce that after a tiny :-) wait of about 5 years, my patent application for a workload manager was finally approved. Background Many operating systems have a resource manager which lets you control machine resources. For example, Solaris provides controls for CPU with several options: shares for proportional CPU allocation. If you have twice as many shares as me, and we are competing for CPU, you'll get about twice as many CPU cycles), dedicated CPU allocation in which a number of CPUs are exclusively dedicated to an application's use. You can say that a zone or project "owns" 8 CPUs on a 32 CPU machine, for example. And, capped CPU in which you specify the upper bound, or cap, of how much CPU an application gets. For example, you can throttle an application to 0.125 of a CPU. (This isn't meant to be an exhaustive list of Solaris RM controls.) Workload management Useful as that is (and tragic that some other operating systems have little resource management and isolation, and frighten people into running only 1 app per OS instance - and wastefully size every server for the peak workload it might experience) that's not really workload management. With resource management one controls the resources, and hope that's enough to meet application service objectives. In fact, we hold resource distribution constant, see if that was good enough, and adjust resource distribution if that didn't meet service level objectives. Here's an example of what happens today: Let's try 30% dedicated CPU. Not enough? Let's try 80% Oh, that's too much, and we're achieving much better response time than the objective, but other workloads are starving. Let's back that off and try again. It's not the process I object to - it's that we to often do this manually. Worse, we sometimes identify and adjust the wrong resource and fiddle with that to no useful result. Back in my days as a customer managing large systems, one of my users would call me up to beg for a "CPU boost": Me: "it won't make any difference - there's plenty of spare CPU to be had, and your application is completely I/O bound." User: "Please do it anyway." Me: "oh, all right, but it won't do you any good." (I did, because he was a friend, but it didn't help.) Prior art There are some operating environments that take a stab about workload management (rather than resource management) but I find them lacking. I know of one that uses synthetic "service units" composed of the sum of CPU, I/O and memory allocations multiplied by weighting factors. A workload is set to make a target rate of service units consumed per second. But this seems to be missing a key point: what is the relationship between artificial 'service units' and actually meeting a throughput or response time objective? What if I get plenty of one of the components (so am getting enough service units), but not enough of the resource whose needed to remove the bottleneck? Actual workload management That's not really the answer either. What is needed is to specify a workload's service levels in terms of externally visible metrics that are meaningful to a business, such as response times or transactions per second, and have the workload manager figure out which resources are not being adequately provided, and then adjust it as needed. If an application is not meeting its service level objectives and the reason is that it's not getting enough CPU cycles, adjust its CPU resource accordingly. If the reason is that the application isn't getting enough RAM to keep its working set in memory, then adjust its RAM assignment appropriately so it stops swapping. Simple idea, but that's a task we keep dumping on system administrators. In other words - don't hold the number of CPU shares constant and watch the achievement of service level vary. Instead, hold the service level constant, and dynamically adjust the number of CPU shares (or amount of other resources like RAM or I/O bandwidth) in order to meet the objective. Instrumenting non-instrumented applications There's one little problem here: how do I measure application performance in a way relating to a service level. I don't want to do it based on internal resources like number of CPU seconds it received per minute - We need to make resource decisions based on externally visible and meaningful measures of performance, not synthetic items or internal resource counters. If I have a way of marking the beginning and end of a transaction, I can then measure whether or not the application is meeting an objective based on it. If I can observe the delay factors for an application, I can see which resource shortages are slowing an application enough to keep it from meeting its objectives. I can then adjust resource allocations to relieve those shortages. Fortunately, Solaris provides facilities for both marking application progress and determining what factors cause application latency. The Solaris DTrace facility let's me introspect on application behavior: in particular I can see events like "receive a web hit" and "respond to that web hit" so I can get transaction rate and response time. DTrace (and tools like prstat) let me see where latency is being added to an application, so I know which resource to adjust. Summary After a delay of a mere few years, I am the proud creator of a patent (advice to anyone interested in going through the process: don't hold your breath!). The fundamental idea is fairly simple: instead of holding resource constant and suffering variable levels of success meeting service level objectives, properly characterise the service level objective in meaningful terms, instrument the application to see if it's meeting the objective, and then have a workload manager change resource allocations to remove delays preventing service level attainment. I've done it by hand for a long time - I think that's what a computer should do for me.

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• Why bother writing an Windows 8 app?

  - by Dennis Vroegop

  So you want to know more about development for Window 8. Great! There are lots of reasons you should be excited about this. Since I don’t know why YOU are interested in this, I’ll make a list of reasons people can choose from. (as a side note: whenever I talk about Win8 development I am referring to the Metro Style / WinRt side of things. Apps for the ‘classic’ desktop side of Win8 on Intel are business as usual…) So… Why would you care about making an app for Windows 8? 1. It’s cool. Let’s not beat around the bush: if you like development for a hobby then you’ll love to work on this new platform. You can create apps in a relative short time (short time as in compared to writing a new CRM system) and that makes it great for a hobby product. 2. You’ll stand out. Hey, we all need an ego boost every now and then. We all need to feel special. So if you can manage to be one of the first to have you app in the Store then you’ll likely to be noticed. Just close your eyes for a moment and image you standing in a bar. It’s crowded, and then you casually say “Oh yeah, I just had my app certified and it’s in the Win8 store now”. People will stop talking, will offer you drinks and beautiful women / gorgeous man / furry creatures from Alpha Centauri (whatever your preferences are) will propose. Or maybe not. Anyway…. 3. Make some cash! IDC predicts there will be about 350,000,000 Windows 8 licenses sold in the next year. Think about that number. 350,000,000. And they all have access to the Store. Where you’re app will be. With one little click they can select it, download and somehow magically $1.00 or $2.00 from their bank account is transferred to yours. Now, I am not saying that all of those people will download and buy your app but what if only 1% of them did? Remember: there aren’t that many apps available yet….. 4. Learn. Creating new small apps is a great way to learn new stuff. Yes, you could read about it (on this blog for instance) but the only way to learn something is to do it. So be prepared for the future and learn something new by doing it.Write an app! Now! 5. The biggie (for me at least): it’s fun. Even if you remove the points above it’s still fun to write for these devices and this platform. Now some of you will say : “But why not write a great app for IOS or Android?” I think this is a valid question. Of course the novelty of the platform wears out and points 2 and 3 from above list will not be as relevant as it is today. But still 1 4 and 5 remain. And don’t forget: if you already work on the Microsoft platform it’s not that hard to learn this new Win8 stuff. If you have done some XAML development (be it WPF or Silverlight) you are almost there in becoming a good Win8 developer. So you’ll be more productive much sooner than when you have to learn Objective C or Java. Even if you’re a HTML / Javascript developer (I say developer here, not designer) you’ll be up to speed on Win8 development pretty soon. Yes, you, that funky Web Developer who lives and breathes HTML5, CSS3 and JavaScript / Node.Js / JQuery: you too can be a Win8 developer. A first class Win8 developer! So.. Download the stuff you need from http://dev.windows.com install Windows 8 and Visual Studio 12 and by the time you’re ready I’ll be working on the next article: how to do all this? Happy coding!

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• From the Classroom to the Boardroom

  - by Maria Sandu

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Pens and Paper...these are the only things being a student and being a graduate / professional have in common. Walking in to the offices of Oracle South Africa as a graduate the first thing you notice is how polished and sleek all the people who work here look. 80% of the ladies wear sky-scraper heels and walk with the greatest grace. This was the first of many rude awakenings to remind me that I am no longer a student but a graduate. My first struggle was having to wake up at wee hours of the morning to prepare for work. As a student going to class was almost an optional thing, if you missed a morning class you could always attend an evening class to make up for it or simply attend with another group. But in the workplace, you HAVE to show up every single morning at the same time, with no option of coming in when it suits you and there is definitely no coming in with the evening class/shift. As a student, the earliest hour I ever woke up was 7:00am, anything earlier than that was considered inhumane torture. My reason for waking up every morning as a student was “you have a degree to go get” but as a graduate having to go to work I have to say to myself “here’s to a new day of learning and growing”. My second struggle has come in having to change my beloved wardrobe. Everyone who knows me knows how passionate I am about fashion and shopping. For me Shopping is a BASIC HUMAN RIGHT, that should not be messed with. Therefore it was with great sadness that I swopped my rippled skinny jeans for pin-striped formal pants, my long chandelier earrings for simple studs, my flat shoes for heels, my sheer blouses for crisp white shirts, even my beloved wild hair had to make way for a simple ponytail. Our looks as ladies also came under great scrutiny, we had to acquaint ourselves with some serious grooming tools: the mascara, blush, lip-gloss, blush, a touch of lipstick and a manicure set. Language was a struggle of its own as well. Being a student you learn to relate to your peers in a informal way. In the workplace you have to address everyone with the same respect, including your peers. Words like “Hey buddy” had to make way for “good morning friend”. The month long winter school holiday was one of the things I looked forward to as a student. This was a time where we got to be at home and avoid the coldest month of the year, July. It was the most amazing thing ever, just sleeping and snuggling up to all sorts of warm things but sadly it is now a thing of the past. It is currently winter in South Africa and going to work has become the most unfashionable thing with all the jackets, boots, scarves and gloves. But summer is coming and I will miss those holidays too. As a student the school holidays were like a gift for us to catch a break and not think for a while which was why it was imaginable how someone would go on for the entire year without a break, with only the promise of a mere 21 days annual leave!! Right now I am sure we are all looking forward to taking that annual leave when the time is right. The worst rude awakening I must say, has to be presenting in front of clients and managers. As a student you have the same class mates for almost four years therefore presenting in front of them becomes the norm over the years and your lecturer will always go gently on you. What they don’t tell you at University is that in the real world, time is money and clients pay money to see you present therefore there is no room for error. Clients are not there to give you a score and boost your ego, they expect nothing less than 100% and they will let you know without a second thought. For a graduate this can feel like you are being fed to the sharks, you either get eaten or you swim for your life. At the end of the day, it is all an experience that is meant to groom us into better professional and make us a part of the Red Team. All the sacrifices are worth it and they lead us to being better and more polished professionals. So if you are interested in joining the ECEMEA Sales and Presales Internship Programme, please have a look at http://campus.oracle.com for more information and for our latest vacancies and internships. /* 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:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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• Key Windows Phone Development Concepts

  - by Tim Murphy

  As I am doing more development in and out of the enterprise arena for Windows Phone I decide I would study for the 70-599 test.  I generally take certification tests as a way to force me to dig deeper into a technology.  Between the development and studying I decided it would be good to put a post together of key development features in Windows Phone 7 environment.  Contrary to popular belief the launch of Windows Phone 8 will not obsolete Windows Phone 7 development.  With the launch of 7.8 coming shortly and people who will remain on 7.X for the foreseeable future there are still consumers needing these apps so don’t throw out the baby with the bath water. PhoneApplicationService This is a class that every Windows Phone developer needs to become familiar with.  When it comes to application state this is your go to repository.  It also contains events that help with management of your application’s lifecycle.  You can access it like the following code sample. 1: PhoneApplicationService.Current.State["ValidUser"] = userResult; DeviceNetworkInformation This class allows you to determine the connectivity of the device and be notified when something changes with that connectivity.  If you are making web service calls you will want to check here before firing off. I have found that this class doesn’t actually work very well for determining if you have internet access.  You are better of using the following code where IsConnectedToInternet is an App level property. private void Application_Launching(object sender, LaunchingEventArgs e){ // Validate user access if (Microsoft.Phone.Net.NetworkInformation.NetworkInterface.NetworkInterfaceType != Microsoft.Phone.Net.NetworkInformation.NetworkInterfaceType.None) { IsConnectedToInternet = true; } else { IsConnectedToInternet = false; } NetworkChange.NetworkAddressChanged += new NetworkAddressChangedEventHandler(NetworkChange_NetworkAddressChanged);}void NetworkChange_NetworkAddressChanged(object sender, EventArgs e){ IsConnectedToInternet = (Microsoft.Phone.Net.NetworkInformation.NetworkInterface.NetworkInterfaceType != Microsoft.Phone.Net.NetworkInformation.NetworkInterfaceType.None);} Push Notification Push notification allows your application to receive notifications in a way that reduces the application’s power needs. This MSDN article is a good place to get the basics of push notification, but you can see the essential concept in the diagram below.  There are three types of push notification: toast, Tile and raw.  The first two work regardless of the state of the application where as raw messages are discarded if your application is not running.   Live Tiles Live tiles are one of the main differentiators of the Windows Phone platform.  They allow users to find information at a glance from their start screen without navigating into individual apps.  Knowing how to implement them can be a great boost to the attractiveness of your application. The simplest step-by-step explanation for creating live tiles is here. Local Database While your application really only has Isolated Storage as a data store there are some ways of giving you database functionality to develop against.  There are a number of open source ORM style solutions.  Probably the best and most native way I have found is to use LINQ to SQL.  It does take a significant amount of setup, but the ease of use once it is configured is worth the cost.  Rather than repeat the full concepts here I will point you to a post that I wrote previously. Tasks (Bing, Email) Leveraging built in features of the Windows Phone platform is an easy way to add functionality that would be expensive to develop on your own.  The classes that you need to make yourself familiar with are BingMapsDirectionsTask and EmailComposeTask.  This will allow your application to supply directions and give the user an email path to relay information to friends and associates. Event model Because of the ability for users to switch quickly to switch to other apps or the home screen is just one reason why knowing the Windows Phone event model is important.  You need to be able to save data so that if a user gets a phone call they can come back to exactly where they were in your application.  This means that you will need to handle such events as Launching, Activated, Deactivated and Closing at an application level.  You will probably also want to get familiar with the OnNavigatedTo and OnNavigatedFrom events at the page level.  These will give you an opportunity to save data as a user navigates through your app. Summary This is just a small portion of the concepts that you will use while building Windows Phone apps, but these are some of the most critical.  With the launch of Windows Phone 8 this list will probably expand.  Take the time to investigate these topics further and try them out in your apps. del.icio.us Tags: Windows Phone 7,Windows Phone,WP7,Software Development,70-599

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• C++ strongly typed typedef

  - by Kian

  I've been trying to think of a way of declaring strongly typed typedefs, to catch a certain class of bugs in the compilation stage. It's often the case that I'll typedef an int into several types of ids, or a vector to position or velocity: typedef int EntityID; typedef int ModelID; typedef Vector3 Position; typedef Vector3 Velocity; This can make the intent of code more clear, but after a long night of coding one might make silly mistakes like comparing different kinds of ids, or adding a position to a velocity perhaps. EntityID eID; ModelID mID; if ( eID == mID ) // <- Compiler sees nothing wrong { /*bug*/ } Position p; Velocity v; Position newP = p + v; // bug, meant p + v*s but compiler sees nothing wrong Unfortunately, suggestions I've found for strongly typed typedefs include using boost, which at least for me isn't a possibility (I do have c++11 at least). So after a bit of thinking, I came upon this idea, and wanted to run it by someone. First, you declare the base type as a template. The template parameter isn't used for anything in the definition, however: template < typename T > class IDType { unsigned int m_id; public: IDType( unsigned int const& i_id ): m_id {i_id} {}; friend bool operator==<T>( IDType<T> const& i_lhs, IDType<T> const& i_rhs ); }; Friend functions actually need to be forward declared before the class definition, which requires a forward declaration of the template class. We then define all the members for the base type, just remembering that it's a template class. Finally, when we want to use it, we typedef it as: class EntityT; typedef IDType<EntityT> EntityID; class ModelT; typedef IDType<ModelT> ModelID; The types are now entirely separate. Functions that take an EntityID will throw a compiler error if you try to feed them a ModelID instead, for example. Aside from having to declare the base types as templates, with the issues that entails, it's also fairly compact. I was hoping anyone had comments or critiques about this idea? One issue that came to mind while writing this, in the case of positions and velocities for example, would be that I can't convert between types as freely as before. Where before multiplying a vector by a scalar would give another vector, so I could do: typedef float Time; typedef Vector3 Position; typedef Vector3 Velocity; Time t = 1.0f; Position p = { 0.0f }; Velocity v = { 1.0f, 0.0f, 0.0f }; Position newP = p + v*t; With my strongly typed typedef I'd have to tell the compiler that multypling a Velocity by a Time results in a Position. class TimeT; typedef Float<TimeT> Time; class PositionT; typedef Vector3<PositionT> Position; class VelocityT; typedef Vector3<VelocityT> Velocity; Time t = 1.0f; Position p = { 0.0f }; Velocity v = { 1.0f, 0.0f, 0.0f }; Position newP = p + v*t; // Compiler error To solve this, I think I'd have to specialize every conversion explicitly, which can be kind of a bother. On the other hand, this limitation can help prevent other kinds of errors (say, multiplying a Velocity by a Distance, perhaps, which wouldn't make sense in this domain). So I'm torn, and wondering if people have any opinions on my original issue, or my approach to solving it.

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• ubuntu wifi disconnection & frustratingly connects to unavailable wifi

  - by ashishsony

  Hi, i have already posted this here: here This has happened before with ubuntu 9.1 Beta2 build too that my wifi disconnects if im idle for 5 minutes... so i cant leave my lappy to download anything... i have to keep on continuously using it.. as soon i leave it idle for abt 5 minutes... wifi disconnects... and the pop up asking for password for wifi pops up...with the password already filled in... i just click on connect and it connects again... so whats the use of asking the password if the pre filled in pass works correctly... and this is happening on ubuntu 10.04 Beta2 too... and the workaround is that just open any menu like the applications menu in the taskbar and keep it open... under this state the ubuntu idleness never activates and so the wifi gets never disconnected... this has been confirmed by me many times.. this seems to be repeating again and again... i dont know why... and the second thing i want to report is that there is no way to report this bug from ubuntu... the launchpad.net talks of going through bug reporting process which is done against a definite package... now how does a user know which package would be causing this error?? there should be a more clear process of reporting such bugs to ubuntu team... thirdly the apport utility that reports crashing apps is totally uselss on 10.04 beta 2... as it collests information and reports that i cant submit the report because i dont have 100 other packages... without updating which i cant submit the report.... surely on a beta build there would be packages continuously being updated... so no system would be reported as fully updated... and so no practical apport reporting is possible?? please address these issues... really frustrating all this ... im a big fan of ubuntu but these things really bug me... and just to add fourthly... the suspend/hibernate feature has never ever worked on my toshiba m70-113 laptop... on any ubuntu version... always have to hard reboot after putting into suspend/hibernate mode.. on windows this has never been the case... why cant ubuntu beat windows in such cases too?? i would really like to see this soon... most importantly, when the router switches off... the wifi signals go off... then why the hell ubuntu keeps on connecting to that very wifi like hell and when doesnt connect shows the prompt to manually connect... with the wifi key already filled in... whats the use of saving the key when it has to ask the question from me either to connect or not?? and if its isnt available... just wait when its available.. i have only option to cancel and if i cancel it wont auto-connect!! what the heck?? one can see in the image that it says "authentication required by wireless network" when there isnt any.. as router has gone down!!

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• Making sense of S.M.A.R.T

  - by James

  First of all, I think everyone knows that hard drives fail a lot more than the manufacturers would like to admit. Google did a study that indicates that certain raw data attributes that the S.M.A.R.T status of hard drives reports can have a strong correlation with the future failure of the drive. We find, for example, that after their first scan error, drives are 39 times more likely to fail within 60 days than drives with no such errors. First errors in re- allocations, offline reallocations, and probational counts are also strongly correlated to higher failure probabil- ities. Despite those strong correlations, we find that failure prediction models based on SMART parameters alone are likely to be severely limited in their prediction accuracy, given that a large fraction of our failed drives have shown no SMART error signals whatsoever. Seagate seems like it is trying to obscure this information about their drives by claiming that only their software can accurately determine the accurate status of their drive and by the way their software will not tell you the raw data values for the S.M.A.R.T attributes. Western digital has made no such claim to my knowledge but their status reporting tool does not appear to report raw data values either. I've been using HDtune and smartctl from smartmontools in order to gather the raw data values for each attribute. I've found that indeed... I am comparing apples to oranges when it comes to certain attributes. I've found for example that most Seagate drives will report that they have many millions of read errors while western digital 99% of the time shows 0 for read errors. I've also found that Seagate will report many millions of seek errors while Western Digital always seems to report 0. Now for my question. How do I normalize this data? Is Seagate producing millions of errors while Western digital is producing none? Wikipedia's article on S.M.A.R.T status says that manufacturers have different ways of reporting this data. Here is my hypothesis: I think I found a way to normalize (is that the right term?) the data. Seagate drives have an additional attribute that Western Digital drives do not have (Hardware ECC Recovered). When you subtract the Read error count from the ECC Recovered count, you'll probably end up with 0. This seems to be equivalent to Western Digitals reported "Read Error" count. This means that Western Digital only reports read errors that it cannot correct while Seagate counts up all read errors and tells you how many of those it was able to fix. I had a Seagate drive where the ECC Recovered count was less than the Read error count and I noticed that many of my files were becoming corrupt. This is how I came up with my hypothesis. The millions of seek errors that Seagate produces are still a mystery to me. Please confirm or correct my hypothesis if you have additional information. Here is the smart status of my western digital drive just so you can see what I'm talking about: james@ubuntu:~$ sudo smartctl -a /dev/sda smartctl version 5.38 [x86_64-unknown-linux-gnu] Copyright (C) 2002-8 Bruce Allen Home page is http://smartmontools.sourceforge.net/ === START OF INFORMATION SECTION === Device Model: WDC WD1001FALS-00E3A0 Serial Number: WD-WCATR0258512 Firmware Version: 05.01D05 User Capacity: 1,000,204,886,016 bytes Device is: Not in smartctl database [for details use: -P showall] ATA Version is: 8 ATA Standard is: Exact ATA specification draft version not indicated Local Time is: Thu Jun 10 19:52:28 2010 PDT SMART support is: Available - device has SMART capability. SMART support is: Enabled === START OF READ SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED SMART Attributes Data Structure revision number: 16 Vendor Specific SMART Attributes with Thresholds: ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x002f 200 200 051 Pre-fail Always - 0 3 Spin_Up_Time 0x0027 179 175 021 Pre-fail Always - 4033 4 Start_Stop_Count 0x0032 100 100 000 Old_age Always - 270 5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always - 0 7 Seek_Error_Rate 0x002e 200 200 000 Old_age Always - 0 9 Power_On_Hours 0x0032 098 098 000 Old_age Always - 1468 10 Spin_Retry_Count 0x0032 100 100 000 Old_age Always - 0 11 Calibration_Retry_Count 0x0032 100 100 000 Old_age Always - 0 12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 262 192 Power-Off_Retract_Count 0x0032 200 200 000 Old_age Always - 46 193 Load_Cycle_Count 0x0032 200 200 000 Old_age Always - 223 194 Temperature_Celsius 0x0022 105 102 000 Old_age Always - 42 196 Reallocated_Event_Count 0x0032 200 200 000 Old_age Always - 0 197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0030 200 200 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age Always - 0 200 Multi_Zone_Error_Rate 0x0008 200 200 000 Old_age Offline - 0

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• Improving TCP performance over a gigabit network with lots of connections and high traffic of small packets

  - by MinimeDJ

  I’m trying to improve my TCP throughput over a “gigabit network with lots of connections and high traffic of small packets”. My server OS is Ubuntu 11.10 Server 64bit. There are about 50.000 (and growing) clients connected to my server through TCP Sockets (all on the same port). 95% of of my packets have size of 1-150 bytes (TCP header and payload). The rest 5% vary from 150 up to 4096+ bytes. With the config below my server can handle traffic up to 30 Mbps (full duplex). Can you please advice best practice to tune OS for my needs? My /etc/sysctl.cong looks like this: kernel.pid_max = 1000000 net.ipv4.ip_local_port_range = 2500 65000 fs.file-max = 1000000 # net.core.netdev_max_backlog=3000 net.ipv4.tcp_sack=0 # net.core.rmem_max = 16777216 net.core.wmem_max = 16777216 net.core.somaxconn = 2048 # net.ipv4.tcp_rmem = 4096 87380 16777216 net.ipv4.tcp_wmem = 4096 65536 16777216 # net.ipv4.tcp_synack_retries = 2 net.ipv4.tcp_syncookies = 1 net.ipv4.tcp_mem = 50576 64768 98152 # net.core.wmem_default = 65536 net.core.rmem_default = 65536 net.ipv4.tcp_window_scaling=1 # net.ipv4.tcp_mem= 98304 131072 196608 # net.ipv4.tcp_timestamps = 0 net.ipv4.tcp_rfc1337 = 1 net.ipv4.ip_forward = 0 net.ipv4.tcp_congestion_control=cubic net.ipv4.tcp_tw_recycle = 0 net.ipv4.tcp_tw_reuse = 0 # net.ipv4.tcp_orphan_retries = 1 net.ipv4.tcp_fin_timeout = 25 net.ipv4.tcp_max_orphans = 8192 Here are my limits: $ ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 193045 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 1000000 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 8192 cpu time (seconds, -t) unlimited max user processes (-u) 1000000 [ADDED] My NICs are the following: $ dmesg | grep Broad [ 2.473081] Broadcom NetXtreme II 5771x 10Gigabit Ethernet Driver bnx2x 1.62.12-0 (2011/03/20) [ 2.477808] bnx2x 0000:02:00.0: eth0: Broadcom NetXtreme II BCM57711E XGb (A0) PCI-E x4 5GHz (Gen2) found at mem fb000000, IRQ 28, node addr d8:d3:85:bd:23:08 [ 2.482556] bnx2x 0000:02:00.1: eth1: Broadcom NetXtreme II BCM57711E XGb (A0) PCI-E x4 5GHz (Gen2) found at mem fa000000, IRQ 40, node addr d8:d3:85:bd:23:0c [ADDED 2] ethtool -k eth0 Offload parameters for eth0: rx-checksumming: on tx-checksumming: on scatter-gather: on tcp-segmentation-offload: on udp-fragmentation-offload: off generic-segmentation-offload: on generic-receive-offload: on large-receive-offload: on rx-vlan-offload: on tx-vlan-offload: on ntuple-filters: off receive-hashing: off [ADDED 3] sudo ethtool -S eth0|grep -vw 0 NIC statistics: [1]: rx_bytes: 17521104292 [1]: rx_ucast_packets: 118326392 [1]: tx_bytes: 35351475694 [1]: tx_ucast_packets: 191723897 [2]: rx_bytes: 16569945203 [2]: rx_ucast_packets: 114055437 [2]: tx_bytes: 36748975961 [2]: tx_ucast_packets: 194800859 [3]: rx_bytes: 16222309010 [3]: rx_ucast_packets: 109397802 [3]: tx_bytes: 36034786682 [3]: tx_ucast_packets: 198238209 [4]: rx_bytes: 14884911384 [4]: rx_ucast_packets: 104081414 [4]: rx_discards: 5828 [4]: rx_csum_offload_errors: 1 [4]: tx_bytes: 35663361789 [4]: tx_ucast_packets: 194024824 [5]: rx_bytes: 16465075461 [5]: rx_ucast_packets: 110637200 [5]: tx_bytes: 43720432434 [5]: tx_ucast_packets: 202041894 [6]: rx_bytes: 16788706505 [6]: rx_ucast_packets: 113123182 [6]: tx_bytes: 38443961940 [6]: tx_ucast_packets: 202415075 [7]: rx_bytes: 16287423304 [7]: rx_ucast_packets: 110369475 [7]: rx_csum_offload_errors: 1 [7]: tx_bytes: 35104168638 [7]: tx_ucast_packets: 184905201 [8]: rx_bytes: 12689721791 [8]: rx_ucast_packets: 87616037 [8]: rx_discards: 2638 [8]: tx_bytes: 36133395431 [8]: tx_ucast_packets: 196547264 [9]: rx_bytes: 15007548011 [9]: rx_ucast_packets: 98183525 [9]: rx_csum_offload_errors: 1 [9]: tx_bytes: 34871314517 [9]: tx_ucast_packets: 188532637 [9]: tx_mcast_packets: 12 [10]: rx_bytes: 12112044826 [10]: rx_ucast_packets: 84335465 [10]: rx_discards: 2494 [10]: tx_bytes: 36562151913 [10]: tx_ucast_packets: 195658548 [11]: rx_bytes: 12873153712 [11]: rx_ucast_packets: 89305791 [11]: rx_discards: 2990 [11]: tx_bytes: 36348541675 [11]: tx_ucast_packets: 194155226 [12]: rx_bytes: 12768100958 [12]: rx_ucast_packets: 89350917 [12]: rx_discards: 2667 [12]: tx_bytes: 35730240389 [12]: tx_ucast_packets: 192254480 [13]: rx_bytes: 14533227468 [13]: rx_ucast_packets: 98139795 [13]: tx_bytes: 35954232494 [13]: tx_ucast_packets: 194573612 [13]: tx_bcast_packets: 2 [14]: rx_bytes: 13258647069 [14]: rx_ucast_packets: 92856762 [14]: rx_discards: 3509 [14]: rx_csum_offload_errors: 1 [14]: tx_bytes: 35663586641 [14]: tx_ucast_packets: 189661305 rx_bytes: 226125043936 rx_ucast_packets: 1536428109 rx_bcast_packets: 351 rx_discards: 20126 rx_filtered_packets: 8694 rx_csum_offload_errors: 11 tx_bytes: 548442367057 tx_ucast_packets: 2915571846 tx_mcast_packets: 12 tx_bcast_packets: 2 tx_64_byte_packets: 35417154 tx_65_to_127_byte_packets: 2006984660 tx_128_to_255_byte_packets: 373733514 tx_256_to_511_byte_packets: 378121090 tx_512_to_1023_byte_packets: 77643490 tx_1024_to_1522_byte_packets: 43669214 tx_pause_frames: 228 Some info about SACK: When to turn TCP SACK off?

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• "Can't create table" when having to many partitions

  - by Chris

  I am currently having a problem I dont understand. Wherever I look it says mySQL (5.5) / InnoDB doesnt have a table limit. I wanted to test the InnoDB compression and was about to create an empty copy of an existing table and ran into the following problem. this one works: CREATE TABLE `hsc` ( LOTS OF STUFF ) ENGINE=InnoDB CHARSET=utf8 PARTITION BY RANGE (pid) SUBPARTITION BY HASH (cons) SUBPARTITIONS 2 (PARTITION hsc_p0 VALUES LESS THAN (10000) , PARTITION hsc_p1 VALUES LESS THAN (20000) , PARTITION hsc_p2 VALUES LESS THAN (30000) , PARTITION hsc_p3 VALUES LESS THAN (40000) , PARTITION hsc_p4 VALUES LESS THAN (50000) , PARTITION hsc_p40 VALUES LESS THAN (4000000) ); this one doesn't: CREATE TABLE `hsc` ( LOTS OF STUFF ) ENGINE=InnoDB CHARSET=utf8 PARTITION BY RANGE (pid) SUBPARTITION BY HASH (cons) SUBPARTITIONS 2 (PARTITION hsc_p0 VALUES LESS THAN (10000) , PARTITION hsc_p1 VALUES LESS THAN (20000) , PARTITION hsc_p2 VALUES LESS THAN (30000) , PARTITION hsc_p3 VALUES LESS THAN (40000) , PARTITION hsc_p4 VALUES LESS THAN (50000) , PARTITION hsc_p5 VALUES LESS THAN (75000) , PARTITION hsc_p6 VALUES LESS THAN (100000) , PARTITION hsc_p7 VALUES LESS THAN (125000) , PARTITION hsc_p8 VALUES LESS THAN (150000) , PARTITION hsc_p9 VALUES LESS THAN (175000) , PARTITION hsc_p40 VALUES LESS THAN (4000000) ); ERROR 1005 (HY000): Can't create table 'hsc' (errno: 1) Its reproducable by removing the number of partitions and adding them again. it does not have to do anything with the name of the table as i tried various names. there is also enough empty space on the HDD. /dev/simfs 230G 26G 192G 12% /var/lib/mysql.mnt There should be no limit on the partitions http://dev.mysql.com/doc/refman/5.5/en/partitioning-limitations.html Maximum number of partitions. The maximum possible number of partitions for a given table (that does not use the NDB storage engine) is 1024. This number includes subpartitions. i have increased both open_files show variables where variable_name LIKE '%open_files%'; +-------------------+-------+ | Variable_name | Value | +-------------------+-------+ | innodb_open_files | 512 | | open_files_limit | 1536 | +-------------------+-------+ No change. Any clues where should I start looking? UPDATE: the whole thing is running in an openvz environment. i saw in users_beancounters that the numflock was a problem, so i increased it. but the problem still persists. maybe this helps: ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 515011 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 1024 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 10240 cpu time (seconds, -t) unlimited max user processes (-u) 515011 virtual memory (kbytes, -v) unlimited file locks (-x) unlimited cat /proc/user_beancounters Version: 2.5 uid resource held maxheld barrier limit failcnt 200: kmemsize 9309653 13357056 14372700 14790164 0 lockedpages 0 1008 2048 2048 0 privvmpages 675424 686528 1048576 1572864 0 shmpages 33 673 21504 21504 0 dummy 0 0 9223372036854775807 9223372036854775807 0 numproc 49 90 240 240 0 physpages 243761 246945 0 9223372036854775807 0 vmguarpages 0 0 1048576 1048576 0 oomguarpages 81672 83305 1048576 1048576 0 numtcpsock 6 8 360 360 0 numflock 175 188 512 512 8 numpty 1 9 16 16 0 numsiginfo 0 48 256 256 0 tcpsndbuf 104640 263912 1720320 2703360 0 tcprcvbuf 98304 131072 1720320 2703360 0 othersockbuf 32368 89304 1126080 2097152 0 dgramrcvbuf 0 2312 262144 262144 0 numothersock 19 28 360 360 0 dcachesize 2285052 3624426 3409920 3624960 0 numfile 616 870 9312 9312 0 dummy 0 0 9223372036854775807 9223372036854775807 0 dummy 0 0 9223372036854775807 9223372036854775807 0 dummy 0 0 9223372036854775807 9223372036854775807 0 numiptent 24 24 128 128 0

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• Hardware recommendations / parts list for a modern, quiet ZFS NAS box - 2011-Feb edition [closed]

  - by dandv

  I want to build some really reliable storage for my data, and it seems that ZFS is the only filesystem at the moment that does live checksumming. That rules out DroboPro, so I'm looking to building a quiet ZFS NAS that would start with 4 2TB or larger hard drives. I'd like this system to be very reliable and relatively future-proof for 2-3 years, so I'm willing to invest some $$$ and buy higher end components. I did see questions here and on other forums about low-cost servers, but I'm not looking for those. I'd be super happy to go for an off-the-shelf solution, but I haven't found one that's quiet. I started doing the research (summarized on my wiki), but I realized that it just gets too complicated for what I know as a software dude, and I'm entering the analysis paralysis area. At this point, I'm basically looking for a parts list for a configuration that will work (and is modern), and I know there are folks around here who are way more competent than me. I've built computers and am comfortable assembling one and messing with *nix; I can follow guides; I just want to end the decision process for the hardware and software configuration. What I've researched so far (not that these are very modern components): Case: I think I've settled on the Antec Twelve Hundred case because it cools well, is quiet, and simply has 12 bays that allow elastic mounting. The SilverStone Raven is its counter-candidate, but I find its construction quite odd. For the PSU, I'm torn between Antec CP-850 and Nexus RX-8500, but I did this research more than a year ago. The Nexus has a very uniform power profile, and I'd rather not have the Antec spin up and down based on load. On the other hand, I'm not sure how often my file server will draw more than 400W under use. For the hard drives, I've read that WD Black drives are actually WD RE3 with a software setting changed. I'd also like to buy different drive types, not just 4 WDs. Recommendations? Right now I have a 2TB Hitachi Deskstar 7K300. For the motherboard, CPU and RAM I have no idea, other than the RAM must be ECC. I already asked a question here about ECC RAM, but I was misguided and was looking for a motherboard that would support USB 3.0 as well. I've learned to go with eSATA, or worry about USB later. Then there's the (liquid) cooling, Wi-Fi card, and FreeBSD vs. OpenSolaris Express. Lastly, I'm wondering if I can make this PC into a media server by adding a Blu-ray drive and a good sound card. But support for Blu-Ray is spotty on Linux, and I don't know if Windows 7 on VirtualBox would get sufficient hardware access to output HDMI or SPDIFF signals. (Running OpenSolaris virtualized is not an option because of the reliability risk.) Then there are HDCP concerns. Suggestions on that would be appreciated as well, but I don't want us to get sidetracked. A specific shopping list on the core components would be great, so I can start ordering, and in the meantime educate myself with regards to the other issues. Finally, I think this could become a great FAQ for those technically inclined to build their own ZFS server, but confused by the dizzying array of options out there, and I promise to compile the results and share my experience building and benchmarking the server.

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