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  • How to deal with ad-hoc mindsets?

    - by Rotian
    I joined a dev team of six two month ago. People are nice, all is good. But more and more I observe an ad-hoc mindset. Stuff gets quick fixed, at the cost of future usability, there is little testing and two people happily admitted, that they like to carry the knowledge around in their head, rather than to write it down. How to deal with this? I'd like to lead by example, but time is limited - I like architecting and actually implementing the stuff. But I'm afraid the ad-hoc mindset infects me and rather than striving for clearness and simplicity in design and code - which isn't simple to establish - I get pulled down the drain of an endless spiral of hacks on hacks - which no outsider can uncouple - just for schedule's and management's sake.

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  • What should I learn to create web-services like ones listed? [closed]

    - by Gerald Blizz
    I am very inspired by websites like imgur, dropbox, screencloud, maybe w3schools...you get my point. Fresh web-services with some new idea, not big portals but something simple yet useful and used by many people, something simple and new. What aspects of my developer career should I focus to be able to build such things on my own if I have enough ideas? (Sure if it ends up being popular I can get more developers to help me and so on, but at first I can do it alone, right?) I am currently a PHP web-developer, I know HTML+CSS+JS+AJAX+JQuery. But even like that there still is web-design, there are a lot of paths: websites for enterprise, startups, webservices, entertainment websites and serious bank/document flow systems, frameworks used for big systems, different approaches for little ones, etcetcetc. Which path should I take to be able to start my own projects like the ones that I listed on top which inspire me?

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  • Do employers prefer software engineering over CS majors?

    - by Joey Green
    I'm in grad school at a university that was one of the first to have a software engineering accredited program. My undergrad is in CS. An employer recently recruited at our university and hired 5 SE majors. None of them were CS. Do employers prefer software engineering majors? The reason I ask is because I can focus on many different areas during my graduate studies and really want to take the classes that will help me land a great job. Right now I'm either going to use CUDA and parallelize an advanced ray-tracer for a graduate project or do research on non-photo-realistic rendering in augmented reality. Pursuing these would leave very little SE classes in my schedule. If I went the software engineering route, I would probably either do research into data-oriented programming or software design complexity. Sometimes I think when I'm 40 and look back will it matter at all? For some reason I'm thinking not.

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  • Speaking at Windows Phone 7 Developer Day Sarasota.NET Group - 1/19/2010

    - by Nikita Polyakov
    SarasotaDev January 2011 Meeting Windows Phone 7 Developer Day [note: this meeting starts at 4pm] The meeting date is Wednesday, January 19, 2011 at 4:00pm - 8:00pm. Location: Sarasota Community Foundation, at 2635 Fruitville Rd., Sarasota, FL 34237 (just west of Tuttle on the north side of Fruitville). We will have 3 speakers, including 2 Microsoft MVPs: Kevin Wolf and Nikita Polyakov, and joined by Russ Fustino. They will present various aspects of WinPhone 7 development, from Silverlight UI design, to instrumenting your apps for run-time analytics, through putting your application into the WinPhone Marketplace. There will be plenty of time for questions and discussion, and we're working on a sponsor for pizza. This will be a great session, even if you're not currently developing phone apps.   http://sarasotadev.net

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  • Why We Should Learn to Stop Worrying and Love Millennials

    - by HCM-Oracle
    By Christine Mellon Much is said and written about the new generations of employees entering our workforce, as though they are a strange specimen, a mysterious life form to be “figured out,” accommodated and engaged – at a safe distance, of course.  At its worst, this talk takes a critical and disapproving tone, with baby boomer employees adamantly refusing to validate this new breed of worker, let alone determine how to help them succeed and achieve their potential.   The irony of our baby-boomer resentments and suspicions is that they belie the fact that we created the very vision that younger employees are striving to achieve.  From our frustrations with empty careers that did not fulfill us, from our opposition to “the man,” from our sharp memories of our parents’ toiling for 30 years just for the right to retire, from the simple desire not to live our lives in a state of invisibility, came the seeds of hope for something better. One characteristic of Millennial workers that grew from these seeds is the desire to experience as much as possible.  They are the “Experiential Employee”, with a passion for growing in diverse ways and expanding personal and professional horizons.  Rather than rooting themselves in a single company for a career, or even in a single career path, these employees are committed to building a broad portfolio of experiences and capabilities that will enable them to make a difference and to leave a mark of significance in the world.  How much richer is the organization that nurtures and leverages this inclination?  Our curmudgeonly ways must be surrendered and our focus redirected toward building the next generation of talent ecosystems, if we are to optimize what future generations have to offer.   Accelerating Professional Development In spite of our Boomer grumblings about Millennials’ “unrealistic” expectations, the truth is that we have a well-matched set of circumstances.  We have executives-in-waiting who want to learn quickly and a concurrent, urgent need to ramp up their development time, based on anticipated high levels of retirement in the next 10+ years.  Since we need to rapidly skill up these heirs to the corporate kingdom, isn’t it a fortunate coincidence that they are hungry to learn, develop and move fluidly throughout our organizations??  So our challenge now is to efficiently operationalize the wisdom we have acquired about effective learning and development.   We have already evolved from classroom-based models to diverse instructional methods.  The next step is to find the best approaches to help younger employees learn quickly and apply new learnings in an impactful way.   Creating temporary or even permanent functional partnerships among Millennial employees is one way to maximize outcomes.  This might take the form of 2 or more employees owning aspects of what once fell under a single role.  While one might argue this would mean duplication of resources, it could be a short term cost while employees come up to speed.  And the potential benefits would be numerous:  leveraging and validating the inherent sense of community of new generations, creating cross-functional skills with broad applicability, yielding additional perspectives and approaches to traditional work outcomes, and accelerating the performance curve for incumbents through Cooperative Learning (Johnson, D. and Johnson R., 1989, 1999).  This well-researched teaching strategy, where students support each other in the absorption and application of new information, has been shown to deliver faster, more efficient learning, and greater retention. Alternately, perhaps short term contracts with exiting retirees, or former retirees, to help facilitate the development of following generations may have merit.  Again, a short term cost, certainly.  However, the gains realized in shortening the learning curve, and strengthening engagement are substantial and lasting. Ultimately, there needs to be creative thinking applied for each organization on how to accelerate the capabilities of our future leaders in unique ways that mesh with current culture. The manner in which performance is evaluated must finally shift as well.  Employees will need to be assessed on how well they have developed key skills and capabilities vs. end-to-end mastery of functional positions they have no interest in keeping for an entire career. As we become more comfortable in placing greater and greater weight on competencies vs. tasks, we will realize increased organizational agility via this new generation of workers, which will be further enhanced by their natural flexibility and appetite for change. Revisiting Succession  For many years, organizations have failed to deliver desired succession planning outcomes.  According to CEB’s 2013 research, only 28% of current leaders were pre-identified in a succession plan. These disappointing results, along with the entrance of the experiential, Millennial employee into the workforce, may just provide the needed impetus for HR to reinvent succession processes.   We have recognized that the best professional development efforts are not always linear, and the time has come to fully adopt this philosophy in regard to succession as well.  Paths to specific organizational roles will not look the same for newer generations who seek out unique learning opportunities, without consideration of a singular career destination.  Rather than charting particular jobs as precursors for key positions, the experiences and skills behind what makes an incumbent successful must become essential in succession mapping.  And the multitude of ways in which those experiences and skills may be acquired must be factored into the process, along with the individual employee’s level of learning agility. While this may seem daunting, it is necessary and long overdue.  We have talked about the criticality of competency-based succession, however, we have not lived up to our own rhetoric.  Many Boomers have experienced the same frustration in our careers; knowing we are capable of shining in a particular role, but being denied the opportunity due to how our career history lined up, on paper, with documented job requirements.  These requirements usually emphasized past jobs/titles and specific tasks, versus capabilities, drive and willingness (let alone determination) to learn new things.  How satisfying would it be for us to leave a legacy where such narrow thinking no longer applies and potential is amplified? Realizing Diversity Another bloom from the seeds we Boomers have tried to plant over the past decades is a completely evolved view of diversity.  Millennial employees assume a diverse workforce, and are startled by anything less.  Their social tolerance, nurtured by wide and diverse networks, is unprecedented.  College graduates expect a similar landscape in the “real world” to what they experienced throughout their lives.  They appreciate and seek out divergent points of view and experiences without needing any persuasion.  The face of our U.S. workforce will likely see dramatic change as Millennials apply their fresh take on hiring and building strong teams, with an inherent sense of inclusion.  This wonderful aspect of the Millennial wave should be celebrated and strongly encouraged, as it is the fulfillment of our own aspirations. Future Perfect The Experiential Employee is operating more as a free agent than a long term player, and their commitment will essentially last as long as meaningful organizational culture and personal/professional opportunities keep their interest.  As Boomers, we have laid the foundation for this new, spirited employment attitude, and we should take pride in knowing that.  Generations to come will challenge organizations to excel in how they identify, manage and nurture talent. Let’s support and revel in the future that we’ve helped invent, rather than lament what we think has been lost.  After all, the future is always connected to the past.  And as so eloquently phrased by Antoine Lavoisier, French nobleman, chemist and politico:  “Nothing is Lost, Nothing is Created, and Everything is Transformed.” Christine has over 25 years of diverse HR experience.  She has held HR consulting and corporate roles, including CHRO positions for Echostar in Denver, a 6,000+ employee global engineering firm, and Aepona, a startup software firm, successfully acquired by Intel. Christine is a resource to Oracle clients, to assist in Human Capital Management strategy development and implementation, compensation practices, talent development initiatives, employee engagement, global HR management, and integrated HR systems and processes that support the full employee lifecycle. 

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  • How are buttons made to be clicked?

    - by Johnny
    I just want to ask a general question. According to that answer, Ill continue thinking. You know in games there are lots of clickable items. Play button, exit, comboboxes maybe etc. My question is are those buttons drawn in same canvas with background and all other things, or for every different thing there is another canvas object? My question is about for general. Im not asking about a specific game, im asking how they are made generally. Im planning to start a game on Android, and Im confused actually how to design buttons, and other object. Probably Im going to use View/SurfaceView for now. I don't have much experience with OpenGL yet. Thanks in advance.

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  • How much to charge Ruby on Rails Website [closed]

    - by eWizardII
    I figured it be appropriate to ask this question on webmasters, over the stackoverflow site seeing as there are similar questions here. I am freelancing for a client in the Boston area, who has the html/css templates for their site made by another web designer. They are basically looking for someone to set up the template, and then make the backend so that a user can purchase music on their site (they are musicians). I am wondering then what would be an appropriate amount to charge them to develop such a system, I am a student, and this would be my 3rd Ruby on Rails project, but probably at least the 20 web design project I have been hired to do and I have other programming knowledge, Python, C, etc. I am thinking of suggesting that they pay 1000usd to set up such a system, but I don't know if this is appropriate. To me it seems justifiable given my experience, and the low end of RoR developers I have seen charging 25usd/hr all the way up to 150usd/hr. Any advice would be appreciated.

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  • Game Formula/Mechanic

    - by Georgiadis Abraam
    i am trying to design a game for a project i have, The main idea is a 3 Type of Heroes 3 Stat per Hero There are no levels involved so the differences must be located on Stats. Flogic)The logic of fight is that type1hero has good chances winning type2hero, type2hero has good chances type3hero and type3hero has good chances winning type1hero. For over a week i am trying to find a stats based formula that will allow me to fix this but i cant, i was meddling with numbers yesterday and it was decent but i cant extract the formula out of it. Could you plz guide me or give me hints on how should i start creating formulas on a Non lvl game that fulfills the fLogic?

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  • Client/Server Application Using Google App Engine

    - by Kevin Zhang
    Can someone please advise me what is the possible solution of using GAE to make a Client/Serer Application? As far as I know, GAE is designed to do web applications. What I want to do is to have a Java Client(Swing based) deployed on a number of computers and deploy the server on GAE. I found an example on GAE website which teaches how to make a SOAP service using GAE, but I don't know whether using SOAP is a good idea for client/server applications. Can someone give me some hints about how to design this system and what technology should be used? Any advices are welcome. Many thanks.

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  • Do I need a degree in Computer Science to get a Jr Programming job in the world? [closed]

    - by t84
    As above really, do I need to go to Uni to get a job as a Junior C# coder? I'm 26 and have been working in Games (Production) for 6 years and I am thinking of a change, I've had exposure to VB6, VBA, HTML, CSS, PHP, JavaScript over the past few years and did a web design NCFE at College, but other than that, nothing else! I'm teaching myself C# at the moment with books and I was wondering 'how much' I need to learn and also how I can improve my chances of getting a programming job! Am I a late started to learn coding? (I know many people who started at a very young age!) Thanks for the help :)

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  • Which of the following relational database management systems would a company adopt (for migration), if any, MS Access, MS SQL Server or MySQL?

    - by Hassan Hagi
    Dear programmers, as part of my final year university project, I am conducting research into relational database management systems such as Microsoft Office Access 2007, Microsoft SQL Server 2008 and MySQL 5.1. The description does not need to be detailed however; I am trying to find empirical evidence and professional opinion/fact to determine which of the three databases are best suited for the required size of company (stated or unstated). OS: Microsoft windows (XP or newer) Please consider the following, but full details are not necessary: Memory management Migration Design constraints Integrity (data and others) Triggers User constraints Ease of use Performance Crash Recovery (not the operating system) Total Cost of Ownership (TCO) Also any info on Open source (to do with the three RDBMS) Thank you for your time and help. Hassan Hagi

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  • Audiobooks for programmers?

    - by Zoot
    I'm a programmer with a two-hour round trip commute to work each day. I'd like to fill some of that time with audiobooks about software development. Any audiobooks that would help me become a better programmer would be appreciated. I'm thinking that books about design patterns and non-fiction about computing history might be good here, but I'm open to anything. Keeping in mind that I will be listening to this in a car, what are the best audiobooks that I can listen to? EDIT: Many people have also suggested podcasts. This is appreciated, but since podcasts arrive in a constantly arriving stream of data rather than as a finite amount of data, ways to juggle all of these different content streams would also be appreciated. To be more specific to my situation, my commuting vehicle has an MP3 CD player, USB input for MP3 files, and AUX input. I own Android and webOS devices that can be plugged into the AUX input.

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  • SEO Friendly URL for search keywords

    - by Kyojimaru
    I have a website where you can search for a brands, item, and content inside my web. It was designed with tab for each search type, but I want to make the url when changing the tab user friendly and good for SEO. Is it better to have a url for search result like this www.example.com/search/{search_keyword}/{tab} or www.example.com/search/{search_keyword}?tab={tab} or www.example.com/search/?search={search_keyword}&tab={tab} where {search_keyword} is the keyword that user input, and {tab} is either brands / item / content, because when I look at facebook, stackoverflow, and some other website, they use query string for their search keyword Edit My past url is only www.example.com/search/{search_keyword}, and I just added the tab design recently. Consider that I should go with option 1 from the above option, should I make www.example.com/search/{search_keyword} the default for 1 of the 3 tab, and make the other 2 tab with www.example.com/search/{search_keyword}/{tab} to retain the score for the page, or should I make all the tab url with www.example.com/search/{search_keyword}/{tab} and use a permanent redirect from www.example.com/search/{search_keyword} to one of the url tab

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  • I can't program because old coding style. This is normal to programmers?

    - by Renato Dinhani Conceição
    I'm in my first real job as programmer, but I can't solve any problems because of the coding style used. The code here: don't have comments don't have functions (50, 100, 200, 300 or more lines executed in sequence) uses a lot of if statements with a lot of paths has variables that make no sense (eg.: cf_cfop, CF_Natop, lnom, r_procod) uses a language I am unfamiliar with (Visual FoxPro 8 from 2002) I feel like I have gone back to 1970. Is it normal for a programmer familiar with OOP, clean-code, design patterns, etc. to have trouble with coding in this old-fashion way?

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  • Business Logic Layer in MVC Application

    - by Subin Jacob
    In my ASP MVC application I decided to add another Business Layer and made the model only to have properties. All other functionality like save to db, get from db is done on this new Business layer. So now the controller will be calling this business layer and model for various operations. Is it a good approach to design like this? I decided not to use model for this purpose because I would need a number of models for different actions. (for eg, one for edit and other for create)

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  • How to store character moves (sprite animations)?

    - by Saad
    So I'm thinking about making a small rpg, mainly to test out different design patterns I've been learning about. But the one question that I'm not too sure on how to approach is how to store an array of character moves in the best way possible. So let's say I have arrays of different sprites. This is how I'm thinking about implementing it: array attack = new array (10); array attack2 = new array(5); (loop) //blit some image attack.push(imageInstance); (end loop) Now every time I want the animation I call on attack or attack2; is there a better structure? The problem with this is let's say there are 100 different attacks, and a player can have up to 10 attacks equipped. So how do I tell which attack the user has; should I use a hash map?

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  • Verification of UML Class Diagram

    - by Jean Carlos Suárez Marranzini
    This is my UML Class Diagram made in Astah Community, for a tennis scoreboard game. Here's a link to the image (I don't have enough rep to post images): http://i47.tinypic.com/2lsxx90.png Points are calculated based on moves. Moves can be either points (for the player's advantage) or errors (for the opponent's advantage). The Time Machine allows you to travel to previous game states (expressed as scoreboards). The storage component should be able to store matches independently of the serialization format. The serializers and deserializers should be able to do their job regardless of where the storage lies. The GameEngine should be able to apply the rules of the game regardless of the particularities of the game (hence, dependency injection through the Settings class). The outcomes of games, sets and matches should be deducible based on the points and the rules to apply (the logic implementations are there to provide the rules). Could you please verify my design and tell me if there's anything wrong with it? Thanks in advance.

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  • Website content copied - How can I prove that I wrote it?

    - by Remy
    One of our competitors constantly copies all our website content. Now, I assume the trouble is to proof that we wrote the content first and that it is not the other way round. I checked on http://www.archive.org, but there is nothing. Any other way to proof that? FYI: We are a swiss company, so different laws will apply. Solution: [Found later] You can upload your content to this service and that they basically timestamp it. https://myows.com/ Another way we found, is to just print out your copy/design, etc. put it into an envelop and send it to ourself (without actually opening it later of course).

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  • Make my website dynamically loaded data available to Facebook Open Graph Object Scrapper

    - by fvaliquette
    Here is the design of my web site: The user enter myWebsite.com/a/1 .htaccess rules redirect to myWebsite.com/b Now the JavaScript ExtJS library is loading. Extracting the value from the URL (in this case it is “1”) Loading ./xml/1.xml From 1.xml setting the Open Graph data (Title, type, image, etc) Loading data that will be shown to the user from 1.xml into the website. My question is: How can I make the Open Graph data available to Facebook? Facebook do not to load my ExtJS JavaScript Library before extracting the Open Graph Object values from the HTML. Is there an easy solution to this problem? The only solutions I found is to make statics web pages or dynamically pages rendered on the server side but I would like to avoid these since my web page implementation is already finished and I would like to avoid re working on it.

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  • Announcing Four Weeks of SSIS MicroTraining!

    - by andyleonard
    For the next four Tuesdays – 29 Nov, 6 Dec, 13 Dec, and 20 Dec – I will deliver a 30 – 45 minute presentation beginning at 11:00 AM EST on Google+ . Please note Google+ limits attendance to the first ten people who join the Hangout and I have no control over who gets in. The topics will be: 29 Nov – “I See a Control Flow. Now What?” (Creating Your First SSIS Package) 6 Dec – The Incremental Load SSIS Design Pattern 13 Dec – Flat File Fu 20 Dec – SSIS Frameworks Magic Details 29 Nov – “I See a Control...(read more)

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  • Is this how dynamic language copes with dynamic requirement?

    - by Amumu
    The question is in the title. I want to have my thinking verified by experienced people. You can add more or disregard my opinion, but give me a reason. Here is an example requirement: Suppose you are required to implement a fighting game. Initially, the game only includes fighters, who can attack each other. Each fighter can punch, kick or block incoming attacks. Fighters can have various fighting styles: Karate, Judo, Kung Fu... That's it for the simple universe of the game. In an OO like Java, it can be implemented similar to this way: abstract class Fighter { int hp, attack; void punch(Fighter otherFighter); void kick(Fighter otherFighter); void block(Figther otherFighter); }; class KarateFighter extends Fighter { //...implementation...}; class JudoFighter extends Fighter { //...implementation... }; class KungFuFighter extends Fighter { //...implementation ... }; This is fine if the game stays like this forever. But, somehow the game designers decide to change the theme of the game: instead of a simple fighting game, the game evolves to become a RPG, in which characters can not only fight but perform other activities, i.e. the character can be a priest, an accountant, a scientist etc... At this point, to make it more generic, we have to change the structure of our original design: Fighter is not used to refer to a person anymore; it refers to a profession. The specialized classes of Fighter (KaraterFighter, JudoFighter, KungFuFighter) . Now we have to create a generic class named Person. However, to adapt this change, I have to change the method signatures of the original operations: class Person { int hp, attack; List<Profession> skillSet; }; abstract class Profession {}; class Fighter extends Profession { void punch(Person otherFighter); void kick(Person otherFighter); void block(Person otherFighter); }; class KarateFighter extends Fighter { //...implementation...}; class JudoFighter extends Fighter { //...implementation... }; class KungFuFighter extends Fighter { //...implementation ... }; class Accountant extends Profession { void calculateTax(Person p) { //...implementation...}; void calculateTax(Company c) { //...implementation...}; }; //... more professions... Here are the problems: To adapt to the method changes, I have to fix the places where the changed methods are called (refactoring). Every time a new requirement is introduced, the current structural design has to be broken to adapt the changes. This leads to the first problem. Rigid structure makes it hard for code reuse. A function can only accept the predefined types, but it cannot accept future unknown types. A written function is bound to its current universe and has no way to accommodate to the new types, without modifications or rewrite from scratch. I see Java has a lot of deprecated methods. OO is an extreme case because it has inheritance to add up the complexity, but in general for statically typed language, types are very strict. In contrast, a dynamic language can handle the above case as follow: ;;fighter1 punch fighter2 (defun perform-punch (fighter1 fighter2) ...implementation... ) ;;fighter1 kick fighter2 (defun perform-kick (fighter1 fighter2) ...implementation... ) ;;fighter1 blocks attacks from fighter2 (defun perform-block (fighter1 fighter2) ...implementation... ) fighter1 and fighter2 can be anything as long as it has the required data for calculation; or methods (duck typing). You don't have to change from the type Fighter to Person. In the case of Lisp, because Lisp only has a single data structure: list, it's even easier to adapt to changes. However, other dynamic languages can have similar behaviors as well. I work primarily with static languages (mainly C and Java, but working with Java was a long time ago). I started learning Lisp and some other dynamic languages this year. I can see how it helps improving my productivity.

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  • Are there any books dedicated to writing test code? [on hold]

    - by joshin4colours
    There are many programming books dedicated to useful programming and engineering topics, like working with legacy code or particular languages. The best of these books become "standard" or "canonical" references for professional programmers. Are there any books like this (or that could be like this) for writing test code? I don't mean books about Test-Driven Development, nor do I mean books about writing good (clean) code in general. I'm looking for books that discuss test code specifically (unit-level, integration-level, UI-level, design patterns, code structures and organization, etc.)

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  • Books or help on OO Analysis

    - by Pat
    I have this course where we learn about the domain model, use cases, contracts and eventually leap into class diagrams and sequence diagrams to define good software classes. I just had an exam and I got trashed, but part of the reason is we barely have any practical material, I spent at least two good months without drawing a single class diagram by myself from a case study. I'm not here to blame the system or the class I'm in, I'm just wondering if people have some exercise-style books that either provide domain models with glossaries, system sequence diagrams and ask you to use GRASP to make software classes? I could really use some alone-time practicing going from analysis to conception of software entities. I'm almost done with Larman's book called "Applying UML and Patterns An Introduction to Object-Oriented Analysis and Design and Iterative Development, Third Edition". It's a good book, but I'm not doing anything by myself since it doesn't come with exercises. Thanks.

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  • Firefox : Mozilla travaille sur une version sans onglet pour iPad et sur deux autres projets « de rupture » pour son navigateur

    Firefox : Mozilla travaille sur une version sans onglet pour iPad Et sur deux autres projets « de rupture » pour son navigateur Aussi curieux que cela puisse paraitre, Firefox ? un des navigateurs les plus populaires au monde ? n'est pas présent sur la tablette la plus populaire de la planète. Jusqu'ici, Mozilla expliquait cette absence avec plusieurs arguments... qui semblent aujourd'hui être caduques puisque la fondation annonce qu'elle travaille sur un Firefox pour iPad. Une version qui ne sera pas adaptée de celle pour pour bureau, mais bien une version entièrement ré-imaginée « from scratch ». C'est la toute nouvelle équipe « Product Design and Strategy » de Mozi...

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  • Benchmarking MySQL Replication with Multi-Threaded Slaves

    - by Mat Keep
    0 0 1 1145 6530 Homework 54 15 7660 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Cambria; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-ansi-language:EN-US;} The objective of this benchmark is to measure the performance improvement achieved when enabling the Multi-Threaded Slave enhancement delivered as a part MySQL 5.6. As the results demonstrate, Multi-Threaded Slaves delivers 5x higher replication performance based on a configuration with 10 databases/schemas. For real-world deployments, higher replication performance directly translates to: · Improved consistency of reads from slaves (i.e. reduced risk of reading "stale" data) · Reduced risk of data loss should the master fail before replicating all events in its binary log (binlog) The multi-threaded slave splits processing between worker threads based on schema, allowing updates to be applied in parallel, rather than sequentially. This delivers benefits to those workloads that isolate application data using databases - e.g. multi-tenant systems deployed in cloud environments. Multi-Threaded Slaves are just one of many enhancements to replication previewed as part of the MySQL 5.6 Development Release, which include: · Global Transaction Identifiers coupled with MySQL utilities for automatic failover / switchover and slave promotion · Crash Safe Slaves and Binlog · Optimized Row Based Replication · Replication Event Checksums · Time Delayed Replication These and many more are discussed in the “MySQL 5.6 Replication: Enabling the Next Generation of Web & Cloud Services” Developer Zone article  Back to the benchmark - details are as follows. Environment The test environment consisted of two Linux servers: · one running the replication master · one running the replication slave. Only the slave was involved in the actual measurements, and was based on the following configuration: - Hardware: Oracle Sun Fire X4170 M2 Server - CPU: 2 sockets, 6 cores with hyper-threading, 2930 MHz. - OS: 64-bit Oracle Enterprise Linux 6.1 - Memory: 48 GB Test Procedure Initial Setup: Two MySQL servers were started on two different hosts, configured as replication master and slave. 10 sysbench schemas were created, each with a single table: CREATE TABLE `sbtest` (    `id` int(10) unsigned NOT NULL AUTO_INCREMENT,    `k` int(10) unsigned NOT NULL DEFAULT '0',    `c` char(120) NOT NULL DEFAULT '',    `pad` char(60) NOT NULL DEFAULT '',    PRIMARY KEY (`id`),    KEY `k` (`k`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 10,000 rows were inserted in each of the 10 tables, for a total of 100,000 rows. When the inserts had replicated to the slave, the slave threads were stopped. The slave data directory was copied to a backup location and the slave threads position in the master binlog noted. 10 sysbench clients, each configured with 10 threads, were spawned at the same time to generate a random schema load against each of the 10 schemas on the master. Each sysbench client executed 10,000 "update key" statements: UPDATE sbtest set k=k+1 WHERE id = <random row> In total, this generated 100,000 update statements to later replicate during the test itself. Test Methodology: The number of slave workers to test with was configured using: SET GLOBAL slave_parallel_workers=<workers> Then the slave IO thread was started and the test waited for all the update queries to be copied over to the relay log on the slave. The benchmark clock was started and then the slave SQL thread was started. The test waited for the slave SQL thread to finish executing the 100k update queries, doing "select master_pos_wait()". When master_pos_wait() returned, the benchmark clock was stopped and the duration calculated. The calculated duration from the benchmark clock should be close to the time it took for the SQL thread to execute the 100,000 update queries. The 100k queries divided by this duration gave the benchmark metric, reported as Queries Per Second (QPS). Test Reset: The test-reset cycle was implemented as follows: · the slave was stopped · the slave data directory replaced with the previous backup · the slave restarted with the slave threads replication pointer repositioned to the point before the update queries in the binlog. The test could then be repeated with identical set of queries but a different number of slave worker threads, enabling a fair comparison. The Test-Reset cycle was repeated 3 times for 0-24 number of workers and the QPS metric calculated and averaged for each worker count. MySQL Configuration The relevant configuration settings used for MySQL are as follows: binlog-format=STATEMENT relay-log-info-repository=TABLE master-info-repository=TABLE As described in the test procedure, the slave_parallel_workers setting was modified as part of the test logic. The consequence of changing this setting is: 0 worker threads:    - current (i.e. single threaded) sequential mode    - 1 x IO thread and 1 x SQL thread    - SQL thread both reads and executes the events 1 worker thread:    - sequential mode    - 1 x IO thread, 1 x Coordinator SQL thread and 1 x Worker thread    - coordinator reads the event and hands it to the worker who executes 2+ worker threads:    - parallel execution    - 1 x IO thread, 1 x Coordinator SQL thread and 2+ Worker threads    - coordinator reads events and hands them to the workers who execute them Results Figure 1 below shows that Multi-Threaded Slaves deliver ~5x higher replication performance when configured with 10 worker threads, with the load evenly distributed across our 10 x schemas. This result is compared to the current replication implementation which is based on a single SQL thread only (i.e. zero worker threads). Figure 1: 5x Higher Performance with Multi-Threaded Slaves The following figure shows more detailed results, with QPS sampled and reported as the worker threads are incremented. The raw numbers behind this graph are reported in the Appendix section of this post. Figure 2: Detailed Results As the results above show, the configuration does not scale noticably from 5 to 9 worker threads. When configured with 10 worker threads however, scalability increases significantly. The conclusion therefore is that it is desirable to configure the same number of worker threads as schemas. Other conclusions from the results: · Running with 1 worker compared to zero workers just introduces overhead without the benefit of parallel execution. · As expected, having more workers than schemas adds no visible benefit. Aside from what is shown in the results above, testing also demonstrated that the following settings had a very positive effect on slave performance: relay-log-info-repository=TABLE master-info-repository=TABLE For 5+ workers, it was up to 2.3 times as fast to run with TABLE compared to FILE. Conclusion As the results demonstrate, Multi-Threaded Slaves deliver significant performance increases to MySQL replication when handling multiple schemas. This, and the other replication enhancements introduced in MySQL 5.6 are fully available for you to download and evaluate now from the MySQL Developer site (select Development Release tab). You can learn more about MySQL 5.6 from the documentation  Please don’t hesitate to comment on this or other replication blogs with feedback and questions. Appendix – Detailed Results

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