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  • Architect Day: Boston - Agenda Update

    - by Bob Rhubart
    Here's the latest information on the session schedule and content for Oracle Technology Network Architect Day in Boston, MA on September 12, 2012. Registration is open, but seating is limited. When: September 12, 2012 8:30am – 5:00pm Where: Boston Marriott Burlington One Burlington Mall Road Burlington, MA 01803 Register now Agenda Time Session Title Room 8:30 am - 9:00 am Registration and Continental Breakfast Salon E Foyer 9:00 am - 9:15 am Welcome and Opening Comments | Bob Rhubart Salon E 9:15 am - 10:00 am Engineered Systems: Oracle's Vision for the Future | Ralf Dossmann Oracle's Exadata and Exalogic are impressive products in their own right. But working in combination they deliver unparalleled transaction processing performance with up to a 30x increase over existing legacy systems, with the lowest cost of ownership over a 3 or 5 year basis than any other hardware. In this session you'll learn how to leverage Oracle's Engineered Systems within your enterprise to deliver record-breaking performance at the lowest TCO. Salon E 10:00 am - 10:30 am Securing Public and Private Clouds | Anton Nielsen Long before the term "Cloud Computing" existed, Oracle technologies supported and promoted the concept. Centralized data with remote users has been at the core of these technologies for decades. The public cloud, and extending private clouds to the internet, though, has added security challenges never imagined decades ago. This presentation will examine a real life security breach and introduce architecture, technologies and policies to secure public and private clouds.  Salon E 10:30 am - 10:45 am Break 10:45 am - 11:30 am Breakout Sessions (pick one) Cloud Computing - Making IT Simple | Scott Mattoon The road to Cloud Computing is not without a few bumps. This session will help to smooth out your journey by tackling some of the potential complications. We'll examine whether standardization is a prerequisite for the Cloud. We'll look at why refactoring isn't just for application code. We'll check out deployable entities and their simplification via higher levels of abstraction. And we'll close out the session with a look at engineered systems and modular clouds. Salon E Innovations in Grid Computing with Oracle Coherence | Rob Misek Learn how Coherence can increase the availability, scalability and performance of your existing applications with its advanced low-latency data-grid technologies. Also hear some interesting industry-specific use cases that customers had implemented and how Oracle is integrating Coherence into its Enterprise Java stack. Salon C 11:30 am - 12:15 pm Breakout Sessions (pick one) Enterprise Strategy for Cloud Security | Dave Chappelle Security is high on the list of concerns for many organizations as they evaluate their cloud computing options. This session will examine security in the context of the various forms of cloud computing. We'll consider technical and non-technical aspects of security, and discuss several strategies for cloud computing, from both the consumer and producer perspectives. Salon E Oracle Enterprise Manager | Avi Huber Much more than a DB management tool, Oracle Enterprise Manager provides management and monitoring coverage for the entire Oracle stack, and beyond. This session will concentrate on the middleware management functionality in OEM, starting with Real User Experience monitoring, through AppServer management, and into deep-dive Java diagnostics. We’ll discuss Business Driven Application Management (BDAM) and the benefits of top-down monitoring. Lastly, we’ll demonstrate how to trace a specific user experience problem, through a multitier SOA application, to its root cause, deep in the JVM. Salon C 12:15 pm - 1:15 pm Lunch Salon E Foyer 1:15 pm - 2:00 pm Panel Discussion - Q&A with session speakers Salon E 2:00 pm - 2:45 pm Breakout Sessions (pick one) Oracle Cloud Reference Architecture | Anbu Krishnaswamy Cloud initiatives are beginning to dominate enterprise IT roadmaps. Successful adoption of Cloud and the subsequent governance challenges warrant a Cloud reference architecture that is applied consistently across the enterprise. This presentation will answer the important questions: What exactly is a Cloud, why you need it, what changes it will bring to the enterprise, and what are the key capabilities of a Cloud infrastructure are - using Oracle's Cloud Reference Architecture, which is part of the IT Strategies from Oracle (ITSO) Cloud Enterprise Technology Strategy (ETS). Salon E 21st Century SOA | Peter Belknap Service Oriented Architecture has evolved from concept to reality in the last decade. The right methodology coupled with mature SOA technologies has helped customers demonstrate success in both innovation and ROI. In this session you will learn how Oracle SOA Suite's orchestration, virtualization, and governance capabilities provide the infrastructure to run mission critical business and system applications. And we'll take a special look at the convergence of SOA & BPM using Oracle's Unified technology stack. Salon C 2:45 pm - 3:00 pm Break 3:00 pm - 4:00 pm Roundtable Discussion Salon E 4:00 pm - 4:15 pm Closing Comments & Readouts from Roundtables Salon E 4:15 pm - 5:00 pm Networking / Reception Salon E Foyer Note: Session schedule and content subject to change.

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  • Updated Agenda for OTN Architect Day Los Angeles (Oct 25)

    - by Bob Rhubart
    Here's the latest information on the session schedule and content for Oracle Technology Network Architect Day in Los Angeles on October 25, 2012. Registration is open, but seating is limited. When: Thursday October 25 12, 2012 8:30am – 5:00pm Where: Sofitel Los Angeles 8555 Beverly Boulevard Los Angeles, CA 90048 Agenda Time Session Title Room 8:30 am - 9:00 am Registration and Continental Breakfast 9:00 am - 9:15 am Welcome and Opening Comments | Bob Rhubart Beverly Ballroom 9:15 am - 10:00 am Engineered Systems: Oracle's Vision for the Future | Ralf Dossmann Oracle's Exadata and Exalogic are impressive products in their own right. But working in combination they deliver unparalleled transaction processing performance with up to a 30x increase over existing legacy systems, with the lowest cost of ownership over a 3 or 5 year basis than any other hardware. In this session you'll learn how to leverage Oracle's Engineered Systems within your enterprise to deliver record-breaking performance at the lowest TCO. Beverly Ballroom 10:00 am - 10:30 am Monitoring and Managing Applications in the Cloud | Basheer Khan Oracle offers a broad portfolio of software and hardware products and services to enable public, private and hybrid clouds to power the enterprise. However, enterprise cloud computing presents new management challenges, that need to be addressed to realize the economic benefits of cloud computing. In this session you will learn about the methods and tools you can use to proactively monitor your end-to-end Oracle Applications environment in the cloud, define service-level objectives, gain insight into your end users, and troubleshoot performance problems from a single console. Beverly Ballroom 10:30 am - 10:45 am Break 10:45 am - 11:30 am Breakout Sessions (pick one) Cloud Computing - Making IT Simple | Dr. James Baty The road to Cloud Computing is not without a few bumps. This session will help to smooth out your journey by tackling some of the potential complications. We'll examine whether standardization is a prerequisite for the Cloud. We'll look at why refactoring isn't just for application code. We'll check out deployable entities and their simplification via higher levels of abstraction. And we'll close out the session with a look at engineered systems and modular clouds. Beverly Ballroom Innovations in Grid Computing with Oracle Coherence | Ashok Aletty Learn how Oracle Coherence can increase the availability, scalability and performance of your existing applications with its advanced low-latency data-grid technologies. Also hear some interesting industry-specific use cases that customers had implemented and how Oracle is integrating Coherence into its Enterprise Java stack. Hollywood Room 11:30 am - 12:15 pm Breakout Sessions (pick one) Enterprise Strategy for Cloud Security | Dave Chappelle Security is high on the list of concerns for many organizations as they evaluate their cloud computing options. This session will examine security in the context of the various forms of cloud computing. We'll consider technical and non-technical aspects of security, and discuss several strategies for cloud computing, from both the consumer and producer perspectives. Beverly Ballroom Oracle Enterprise Manager | Perren Walker This session examines new Oracle Enterprise Manager monitoring, administration, and management features for Oracle Exalogic. It focuses on two management themes: cloud management related to virtualization and applications-to-disk management. For private cloud management, it discusses virtualization management features providing an enhanced set of application deployment capabilities enabling IaaS as well as PaaS interactions. Then from an end-to-end perspective, it covers the specific capabilities and—where applicable—best practices for machine, cloud, middleware, and application administration. Hollywood Room 12:15 pm - 1:15 pm Lunch Beverly Ballroom Lounge 1:15 pm - 2:00 pm Panel Discussion - Q&A with session speakers Beverly Ballroom 2:00 pm - 2:45 pm Breakout Sessions (pick one) Oracle Cloud Reference Architecture | Anbu Krishnaswamy Cloud initiatives are beginning to dominate enterprise IT roadmaps. Successful adoption of Cloud and the subsequent governance challenges warrant a Cloud reference architecture that is applied consistently across the enterprise. This presentation will answer the important questions: What exactly is a Cloud, why you need it, what changes it will bring to the enterprise, and what are the key capabilities of a Cloud infrastructure are - using Oracle's Cloud Reference Architecture, which is part of the IT Strategies from Oracle (ITSO) Cloud Enterprise Technology Strategy ETS). Beverly Ballroom 21st Century SOA | Jeff Davies Service Oriented Architecture has evolved from concept to reality in the last decade. The right methodology coupled with mature SOA technologies has helped customers demonstrate success in both innovation and ROI. In this session you will learn how Oracle SOA Suite's orchestration, virtualization, and governance capabilities provide the infrastructure to run mission critical business and system applications. We'll also take a special look at the convergence of SOA & BPM using Oracle's Unified technology stack. Hollywood Room 2:45 pm - 3:00 pm Break 3:00 pm - 4:00 pm Roundtable Discussion Beverly Ballroom 4:00 pm - 4:15 pm Closing Comments & Readouts from Roundtables Beverly Ballroom 4:15 pm - 5:00 pm Networking / Reception Beverly Ballroom Lounge Note: Session schedule and content subject to change.

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  • Password-protected sharing allows access to users who have no account?

    - by romkyns
    Running Win7 on two computers in my LAN. Computer A has password-protected sharing enabled, and shares a folder. It has a single user account "Bob", and the Guest account is turned off. The network is workgroup-based. According to the descriptions of the "password-protected sharing" I could find, the only people who can access the shared folder via the LAN are those who know the username+password for the "Bob" account. However a second computer on the LAN is able to view this shared folder by simply browsing to Computer A. They don't need to enter any passwords or anything. The only user account registered on that PC is called "Jim", and has a different password from "Bob". How on earth is computer B able to view this shared folder? Is the popular description of the "password-protected sharing" feature inaccurate / did I misunderstand it big time? P.S. There is a possibility that the password for "Bob" has been entered on that PC once, and possibly the "remember password" box was checked. I've looked in the "Credential Manager" on both computers and there is nothing saved anywhere.

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  • The Inkremental Architect&acute;s Napkin - #4 - Make increments tangible

    - by Ralf Westphal
    Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/06/12/the-inkremental-architectacutes-napkin---4---make-increments-tangible.aspxThe driver of software development are increments, small increments, tiny increments. With an increment being a slice of the overall requirement scope thin enough to implement and get feedback from a product owner within 2 days max. Such an increment might concern Functionality or Quality.[1] To make such high frequency delivery of increments possible, the transition from talking to coding needs to be as easy as possible. A user story or some other documentation of what´s supposed to get implemented until tomorrow evening at latest is one side of the medal. The other is where to put the logic in all of the code base. To implement an increment, only logic statements are needed. Functionality like Quality are just about expressions and control flow statements. Think of Assembler code without the CALL/RET instructions. That´s all is needed. Forget about functions, forget about classes. To make a user happy none of that is really needed. It´s just about the right expressions and conditional executions paths plus some memory allocation. Automatic function inlining of compilers which makes it clear how unimportant functions are for delivering value to users at runtime. But why then are there functions? Because they were invented for optimization purposes. We need them for better Evolvability and Production Efficiency. Nothing more, nothing less. No software has become faster, more secure, more scalable, more functional because we gathered logic under the roof of a function or two or a thousand. Functions make logic easier to understand. Functions make us faster in producing logic. Functions make it easier to keep logic consistent. Functions help to conserve memory. That said, functions are important. They are even the pivotal element of software development. We can´t code without them - whether you write a function yourself or not. Because there´s always at least one function in play: the Entry Point of a program. In Ruby the simplest program looks like this:puts "Hello, world!" In C# more is necessary:class Program { public static void Main () { System.Console.Write("Hello, world!"); } } C# makes the Entry Point function explicit, not so Ruby. But still it´s there. So you can think of logic always running in some function. Which brings me back to increments: In order to make the transition from talking to code as easy as possible, it has to be crystal clear into which function you should put the logic. Product owners might be content once there is a sticky note a user story on the Scrum or Kanban board. But developers need an idea of what that sticky note means in term of functions. Because with a function in hand, with a signature to run tests against, they have something to focus on. All´s well once there is a function behind whose signature logic can be piled up. Then testing frameworks can be used to check if the logic is correct. Then practices like TDD can help to drive the implementation. That´s why most code katas define exactly how the API of a solution should look like. It´s a function, maybe two or three, not more. A requirement like “Write a function f which takes this as parameters and produces such and such output by doing x” makes a developer comfortable. Yes, there are all kinds of details to think about, like which algorithm or technology to use, or what kind of state and side effects to consider. Even a single function not only must deliver on Functionality, but also on Quality and Evolvability. Nevertheless, once it´s clear which function to put logic in, you have a tangible starting point. So, yes, what I´m suggesting is to find a single function to put all the logic in that´s necessary to deliver on a the requirements of an increment. Or to put it the other way around: Slice requirements in a way that each increment´s logic can be located under the roof of a single function. Entry points Of course, the logic of a software will always be spread across many, many functions. But there´s always an Entry Point. That´s the most important function for each increment, because that´s the root to put integration or even acceptance tests on. A batch program like the above hello-world application only has a single Entry Point. All logic is reached from there, regardless how deep it´s nested in classes. But a program with a user interface like this has at least two Entry Points: One is the main function called upon startup. The other is the button click event handler for “Show my score”. But maybe there are even more, like another Entry Point being a handler for the event fired when one of the choices gets selected; because then some logic could check if the button should be enabled because all questions got answered. Or another Entry Point for the logic to be executed when the program is close; because then the choices made should be persisted. You see, an Entry Point to me is a function which gets triggered by the user of a software. With batch programs that´s the main function. With GUI programs on the desktop that´s event handlers. With web programs that´s handlers for URL routes. And my basic suggestion to help you with slicing requirements for Spinning is: Slice them in a way so that each increment is related to only one Entry Point function.[2] Entry Points are the “outer functions” of a program. That´s where the environment triggers behavior. That´s where hardware meets software. Entry points always get called because something happened to hardware state, e.g. a key was pressed, a mouse button clicked, the system timer ticked, data arrived over a wire.[3] Viewed from the outside, software is just a collection of Entry Point functions made accessible via buttons to press, menu items to click, gestures, URLs to open, keys to enter. Collections of batch processors I´d thus say, we haven´t moved forward since the early days of software development. We´re still writing batch programs. Forget about “event-driven programming” with its fancy GUI applications. Software is just a collection of batch processors. Earlier it was just one per program, today it´s hundreds we bundle up into applications. Each batch processor is represented by an Entry Point as its root that works on a number of resources from which it reads data to process and to which it writes results. These resources can be the keyboard or main memory or a hard disk or a communication line or a display. Together many batch processors - large and small - form applications the user perceives as a single whole: Software development that way becomes quite simple: just implement one batch processor after another. Well, at least in principle ;-) Features Each batch processor entered through an Entry Point delivers value to the user. It´s an increment. Sometimes its logic is trivial, sometimes it´s very complex. Regardless, each Entry Point represents an increment. An Entry Point implemented thus is a step forward in terms of Agility. At the same time it´s a tangible unit for developers. Therefore, identifying the more or less numerous batch processors in a software system is a rewarding task for product owners and developers alike. That´s where user stories meet code. In this example the user story translates to the Entry Point triggered by clicking the login button on a dialog like this: The batch then retrieves what has been entered via keyboard, loads data from a user store, and finally outputs some kind of response on the screen, e.g. by displaying an error message or showing the next dialog. This is all very simple, but you see, there is not just one thing happening, but several. Get input (email address, password) Load user for email address If user not found report error Check password Hash password Compare hash to hash stored in user Show next dialog Viewed from 10,000 feet it´s all done by the Entry Point function. And of course that´s technically possible. It´s just a bunch of logic and calling a couple of API functions. However, I suggest to take these steps as distinct aspects of the overall requirement described by the user story. Such aspects of requirements I call Features. Features too are increments. Each provides some (small) value of its own to the user. Each can be checked individually by a product owner. Instead of implementing all the logic behind the Login() entry point at once you can move forward increment by increment, e.g. First implement the dialog, let the user enter any credentials, and log him/her in without any checks. Features 1 and 4. Then hard code a single user and check the email address. Features 2 and 2.1. Then check password without hashing it (or use a very simple hash like the length of the password). Features 3. and 3.2 Replace hard coded user with a persistent user directoy, but a very simple one, e.g. a CSV file. Refinement of feature 2. Calculate the real hash for the password. Feature 3.1. Switch to the final user directory technology. Each feature provides an opportunity to deliver results in a short amount of time and get feedback. If you´re in doubt whether you can implement the whole entry point function until tomorrow night, then just go for a couple of features or even just one. That´s also why I think, you should strive for wrapping feature logic into a function of its own. It´s a matter of Evolvability and Production Efficiency. A function per feature makes the code more readable, since the language of requirements analysis and design is carried over into implementation. It makes it easier to apply changes to features because it´s clear where their logic is located. And finally, of course, it lets you re-use features in different context (read: increments). Feature functions make it easier for you to think of features as Spinning increments, to implement them independently, to let the product owner check them for acceptance individually. Increments consist of features, entry point functions consist of feature functions. So you can view software as a hierarchy of requirements from broad to thin which map to a hierarchy of functions - with entry points at the top.   I like this image of software as a self-similar structure on many levels of abstraction where requirements and code match each other. That to me is true agile design: the core tenet of Agility to move forward in increments is carried over into implementation. Increments on paper are retained in code. This way developers can easily relate to product owners. Elusive and fuzzy requirements are not tangible. Software production is moving forward through requirements one increment at a time, and one function at a time. In closing Product owners and developers are different - but they need to work together towards a shared goal: working software. So their notions of software need to be made compatible, they need to be connected. The increments of the product owner - user stories and features - need to be mapped straightforwardly to something which is relevant to developers. To me that´s functions. Yes, functions, not classes nor components nor micro services. We´re talking about behavior, actions, activities, processes. Their natural representation is a function. Something has to be done. Logic has to be executed. That´s the purpose of functions. Later, classes and other containers are needed to stay on top of a growing amount of logic. But to connect developers and product owners functions are the appropriate glue. Functions which represent increments. Can there always be such a small increment be found to deliver until tomorrow evening? I boldly say yes. Yes, it´s always possible. But maybe you´ve to start thinking differently. Maybe the product owner needs to start thinking differently. Completion is not the goal anymore. Neither is checking the delivery of an increment through the user interface of a software. Product owners need to become comfortable using test beds for certain features. If it´s hard to slice requirements thin enough for Spinning the reason is too little knowledge of something. Maybe you don´t yet understand the problem domain well enough? Maybe you don´t yet feel comfortable with some tool or technology? Then it´s time to acknowledge this fact. Be honest about your not knowing. And instead of trying to deliver as a craftsman officially become a researcher. Research an check back with the product owner every day - until your understanding has grown to a level where you are able to define the next Spinning increment. ? Sometimes even thin requirement slices will cover several Entry Points, like “Add validation of email addresses to all relevant dialogs.” Validation then will it put into a dozen functons. Still, though, it´s important to determine which Entry Points exactly get affected. That´s much easier, if strive for keeping the number of Entry Points per increment to 1. ? If you like call Entry Point functions event handlers, because that´s what they are. They all handle events of some kind, whether that´s palpable in your code or note. A public void btnSave_Click(object sender, EventArgs e) {…} might look like an event handler to you, but public static void Main() {…} is one also - for then event “program started”. ?

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  • How to report a crash bug with nothing on screen

    - by winniemiel05
    I would like to report an installation bug, but I can't launch ubuntu-bug : On my tablet (LDLC Janus, an Intel based tablet without OS installed by default), I have a problem when I install Ubuntu 11.04 or 11.10. Once the installation is finished, when I reboot, there is ABSOLUTELY nothing on screen, but Ubuntu boot correctly anyway : I choosed auto-login mode and I can hear the login sound. Even if I Ctrl+Alt+F1 or F2... there is nothing. But the livecd works fine (even touch screen even if without multi touch). I tried to install 10.10 it works, but as soon as I upgrade the same problem occure. i installed Fedora 15 and then Fedora 16 (because of other problems) and no problems with them. I would like to report this bug on launchpad but I don't know how to do to give devs logs files and other useful files which could help debug. Thanks a lot for your answer, I would really prefer using my tablet with Ubuntu (I miss U1, USC, Unity)

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  • Best Practices in Preventing Locks in File sharing in Windows?

    - by crosenblum
    We have a web development server, that has our source control on it. That we use via mapped drives to open/edit/save/create files on to it. But I have noticed a lot of weird glitches with either the file lock/sharing/etc For example, if i have a file open on my local pc, and try to check out that file via my source control on dev, it error's out. The source control I use is QCVS by Qumasoft. Or If I use cuteftp to download something to dev, via my local pc, it won't download unless I close that file. So my brain sniff's and figures this is either an issue with folder/network/sharing, or an issue of permissions. Has anyone else had similar issues, and what did they do to fix it permanently? Thank you...

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  • No file sharing between two server 2008 R2 machines.

    - by ProfKaos
    I have just replaced XP with Server 2008 R2 on my test sever, and have been running 2008 R2 on my dev laptop. When my server was still XP, file sharing just worked, but now it just doesn't. I've enabled everything I can about sharing, and I can ping the server by machine name, but if I try an access a share, I get asked for a password. The passowrd dialog assumes a domain for this user, but neither my laptop admin user nor my server admin user can get past this login. What am I doing wrong?

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  • The Incremental Architect&rsquo;s Napkin - #5 - Design functions for extensibility and readability

    - by Ralf Westphal
    Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/08/24/the-incremental-architectrsquos-napkin---5---design-functions-for.aspx The functionality of programs is entered via Entry Points. So what we´re talking about when designing software is a bunch of functions handling the requests represented by and flowing in through those Entry Points. Designing software thus consists of at least three phases: Analyzing the requirements to find the Entry Points and their signatures Designing the functionality to be executed when those Entry Points get triggered Implementing the functionality according to the design aka coding I presume, you´re familiar with phase 1 in some way. And I guess you´re proficient in implementing functionality in some programming language. But in my experience developers in general are not experienced in going through an explicit phase 2. “Designing functionality? What´s that supposed to mean?” you might already have thought. Here´s my definition: To design functionality (or functional design for short) means thinking about… well, functions. You find a solution for what´s supposed to happen when an Entry Point gets triggered in terms of functions. A conceptual solution that is, because those functions only exist in your head (or on paper) during this phase. But you may have guess that, because it´s “design” not “coding”. And here is, what functional design is not: It´s not about logic. Logic is expressions (e.g. +, -, && etc.) and control statements (e.g. if, switch, for, while etc.). Also I consider calling external APIs as logic. It´s equally basic. It´s what code needs to do in order to deliver some functionality or quality. Logic is what´s doing that needs to be done by software. Transformations are either done through expressions or API-calls. And then there is alternative control flow depending on the result of some expression. Basically it´s just jumps in Assembler, sometimes to go forward (if, switch), sometimes to go backward (for, while, do). But calling your own function is not logic. It´s not necessary to produce any outcome. Functionality is not enhanced by adding functions (subroutine calls) to your code. Nor is quality increased by adding functions. No performance gain, no higher scalability etc. through functions. Functions are not relevant to functionality. Strange, isn´t it. What they are important for is security of investment. By introducing functions into our code we can become more productive (re-use) and can increase evolvability (higher unterstandability, easier to keep code consistent). That´s no small feat, however. Evolvable code can hardly be overestimated. That´s why to me functional design is so important. It´s at the core of software development. To sum this up: Functional design is on a level of abstraction above (!) logical design or algorithmic design. Functional design is only done until you get to a point where each function is so simple you are very confident you can easily code it. Functional design an logical design (which mostly is coding, but can also be done using pseudo code or flow charts) are complementary. Software needs both. If you start coding right away you end up in a tangled mess very quickly. Then you need back out through refactoring. Functional design on the other hand is bloodless without actual code. It´s just a theory with no experiments to prove it. But how to do functional design? An example of functional design Let´s assume a program to de-duplicate strings. The user enters a number of strings separated by commas, e.g. a, b, a, c, d, b, e, c, a. And the program is supposed to clear this list of all doubles, e.g. a, b, c, d, e. There is only one Entry Point to this program: the user triggers the de-duplication by starting the program with the string list on the command line C:\>deduplicate "a, b, a, c, d, b, e, c, a" a, b, c, d, e …or by clicking on a GUI button. This leads to the Entry Point function to get called. It´s the program´s main function in case of the batch version or a button click event handler in the GUI version. That´s the physical Entry Point so to speak. It´s inevitable. What then happens is a three step process: Transform the input data from the user into a request. Call the request handler. Transform the output of the request handler into a tangible result for the user. Or to phrase it a bit more generally: Accept input. Transform input into output. Present output. This does not mean any of these steps requires a lot of effort. Maybe it´s just one line of code to accomplish it. Nevertheless it´s a distinct step in doing the processing behind an Entry Point. Call it an aspect or a responsibility - and you will realize it most likely deserves a function of its own to satisfy the Single Responsibility Principle (SRP). Interestingly the above list of steps is already functional design. There is no logic, but nevertheless the solution is described - albeit on a higher level of abstraction than you might have done yourself. But it´s still on a meta-level. The application to the domain at hand is easy, though: Accept string list from command line De-duplicate Present de-duplicated strings on standard output And this concrete list of processing steps can easily be transformed into code:static void Main(string[] args) { var input = Accept_string_list(args); var output = Deduplicate(input); Present_deduplicated_string_list(output); } Instead of a big problem there are three much smaller problems now. If you think each of those is trivial to implement, then go for it. You can stop the functional design at this point. But maybe, just maybe, you´re not so sure how to go about with the de-duplication for example. Then just implement what´s easy right now, e.g.private static string Accept_string_list(string[] args) { return args[0]; } private static void Present_deduplicated_string_list( string[] output) { var line = string.Join(", ", output); Console.WriteLine(line); } Accept_string_list() contains logic in the form of an API-call. Present_deduplicated_string_list() contains logic in the form of an expression and an API-call. And then repeat the functional design for the remaining processing step. What´s left is the domain logic: de-duplicating a list of strings. How should that be done? Without any logic at our disposal during functional design you´re left with just functions. So which functions could make up the de-duplication? Here´s a suggestion: De-duplicate Parse the input string into a true list of strings. Register each string in a dictionary/map/set. That way duplicates get cast away. Transform the data structure into a list of unique strings. Processing step 2 obviously was the core of the solution. That´s where real creativity was needed. That´s the core of the domain. But now after this refinement the implementation of each step is easy again:private static string[] Parse_string_list(string input) { return input.Split(',') .Select(s => s.Trim()) .ToArray(); } private static Dictionary<string,object> Compile_unique_strings(string[] strings) { return strings.Aggregate( new Dictionary<string, object>(), (agg, s) => { agg[s] = null; return agg; }); } private static string[] Serialize_unique_strings( Dictionary<string,object> dict) { return dict.Keys.ToArray(); } With these three additional functions Main() now looks like this:static void Main(string[] args) { var input = Accept_string_list(args); var strings = Parse_string_list(input); var dict = Compile_unique_strings(strings); var output = Serialize_unique_strings(dict); Present_deduplicated_string_list(output); } I think that´s very understandable code: just read it from top to bottom and you know how the solution to the problem works. It´s a mirror image of the initial design: Accept string list from command line Parse the input string into a true list of strings. Register each string in a dictionary/map/set. That way duplicates get cast away. Transform the data structure into a list of unique strings. Present de-duplicated strings on standard output You can even re-generate the design by just looking at the code. Code and functional design thus are always in sync - if you follow some simple rules. But about that later. And as a bonus: all the functions making up the process are small - which means easy to understand, too. So much for an initial concrete example. Now it´s time for some theory. Because there is method to this madness ;-) The above has only scratched the surface. Introducing Flow Design Functional design starts with a given function, the Entry Point. Its goal is to describe the behavior of the program when the Entry Point is triggered using a process, not an algorithm. An algorithm consists of logic, a process on the other hand consists just of steps or stages. Each processing step transforms input into output or a side effect. Also it might access resources, e.g. a printer, a database, or just memory. Processing steps thus can rely on state of some sort. This is different from Functional Programming, where functions are supposed to not be stateful and not cause side effects.[1] In its simplest form a process can be written as a bullet point list of steps, e.g. Get data from user Output result to user Transform data Parse data Map result for output Such a compilation of steps - possibly on different levels of abstraction - often is the first artifact of functional design. It can be generated by a team in an initial design brainstorming. Next comes ordering the steps. What should happen first, what next etc.? Get data from user Parse data Transform data Map result for output Output result to user That´s great for a start into functional design. It´s better than starting to code right away on a given function using TDD. Please get me right: TDD is a valuable practice. But it can be unnecessarily hard if the scope of a functionn is too large. But how do you know beforehand without investing some thinking? And how to do this thinking in a systematic fashion? My recommendation: For any given function you´re supposed to implement first do a functional design. Then, once you´re confident you know the processing steps - which are pretty small - refine and code them using TDD. You´ll see that´s much, much easier - and leads to cleaner code right away. For more information on this approach I call “Informed TDD” read my book of the same title. Thinking before coding is smart. And writing down the solution as a bunch of functions possibly is the simplest thing you can do, I´d say. It´s more according to the KISS (Keep It Simple, Stupid) principle than returning constants or other trivial stuff TDD development often is started with. So far so good. A simple ordered list of processing steps will do to start with functional design. As shown in the above example such steps can easily be translated into functions. Moving from design to coding thus is simple. However, such a list does not scale. Processing is not always that simple to be captured in a list. And then the list is just text. Again. Like code. That means the design is lacking visuality. Textual representations need more parsing by your brain than visual representations. Plus they are limited in their “dimensionality”: text just has one dimension, it´s sequential. Alternatives and parallelism are hard to encode in text. In addition the functional design using numbered lists lacks data. It´s not visible what´s the input, output, and state of the processing steps. That´s why functional design should be done using a lightweight visual notation. No tool is necessary to draw such designs. Use pen and paper; a flipchart, a whiteboard, or even a napkin is sufficient. Visualizing processes The building block of the functional design notation is a functional unit. I mostly draw it like this: Something is done, it´s clear what goes in, it´s clear what comes out, and it´s clear what the processing step requires in terms of state or hardware. Whenever input flows into a functional unit it gets processed and output is produced and/or a side effect occurs. Flowing data is the driver of something happening. That´s why I call this approach to functional design Flow Design. It´s about data flow instead of control flow. Control flow like in algorithms is of no concern to functional design. Thinking about control flow simply is too low level. Once you start with control flow you easily get bogged down by tons of details. That´s what you want to avoid during design. Design is supposed to be quick, broad brush, abstract. It should give overview. But what about all the details? As Robert C. Martin rightly said: “Programming is abot detail”. Detail is a matter of code. Once you start coding the processing steps you designed you can worry about all the detail you want. Functional design does not eliminate all the nitty gritty. It just postpones tackling them. To me that´s also an example of the SRP. Function design has the responsibility to come up with a solution to a problem posed by a single function (Entry Point). And later coding has the responsibility to implement the solution down to the last detail (i.e. statement, API-call). TDD unfortunately mixes both responsibilities. It´s just coding - and thereby trying to find detailed implementations (green phase) plus getting the design right (refactoring). To me that´s one reason why TDD has failed to deliver on its promise for many developers. Using functional units as building blocks of functional design processes can be depicted very easily. Here´s the initial process for the example problem: For each processing step draw a functional unit and label it. Choose a verb or an “action phrase” as a label, not a noun. Functional design is about activities, not state or structure. Then make the output of an upstream step the input of a downstream step. Finally think about the data that should flow between the functional units. Write the data above the arrows connecting the functional units in the direction of the data flow. Enclose the data description in brackets. That way you can clearly see if all flows have already been specified. Empty brackets mean “no data is flowing”, but nevertheless a signal is sent. A name like “list” or “strings” in brackets describes the data content. Use lower case labels for that purpose. A name starting with an upper case letter like “String” or “Customer” on the other hand signifies a data type. If you like, you also can combine descriptions with data types by separating them with a colon, e.g. (list:string) or (strings:string[]). But these are just suggestions from my practice with Flow Design. You can do it differently, if you like. Just be sure to be consistent. Flows wired-up in this manner I call one-dimensional (1D). Each functional unit just has one input and/or one output. A functional unit without an output is possible. It´s like a black hole sucking up input without producing any output. Instead it produces side effects. A functional unit without an input, though, does make much sense. When should it start to work? What´s the trigger? That´s why in the above process even the first processing step has an input. If you like, view such 1D-flows as pipelines. Data is flowing through them from left to right. But as you can see, it´s not always the same data. It get´s transformed along its passage: (args) becomes a (list) which is turned into (strings). The Principle of Mutual Oblivion A very characteristic trait of flows put together from function units is: no functional units knows another one. They are all completely independent of each other. Functional units don´t know where their input is coming from (or even when it´s gonna arrive). They just specify a range of values they can process. And they promise a certain behavior upon input arriving. Also they don´t know where their output is going. They just produce it in their own time independent of other functional units. That means at least conceptually all functional units work in parallel. Functional units don´t know their “deployment context”. They now nothing about the overall flow they are place in. They are just consuming input from some upstream, and producing output for some downstream. That makes functional units very easy to test. At least as long as they don´t depend on state or resources. I call this the Principle of Mutual Oblivion (PoMO). Functional units are oblivious of others as well as an overall context/purpose. They are just parts of a whole focused on a single responsibility. How the whole is built, how a larger goal is achieved, is of no concern to the single functional units. By building software in such a manner, functional design interestingly follows nature. Nature´s building blocks for organisms also follow the PoMO. The cells forming your body do not know each other. Take a nerve cell “controlling” a muscle cell for example:[2] The nerve cell does not know anything about muscle cells, let alone the specific muscel cell it is “attached to”. Likewise the muscle cell does not know anything about nerve cells, let a lone a specific nerve cell “attached to” it. Saying “the nerve cell is controlling the muscle cell” thus only makes sense when viewing both from the outside. “Control” is a concept of the whole, not of its parts. Control is created by wiring-up parts in a certain way. Both cells are mutually oblivious. Both just follow a contract. One produces Acetylcholine (ACh) as output, the other consumes ACh as input. Where the ACh is going, where it´s coming from neither cell cares about. Million years of evolution have led to this kind of division of labor. And million years of evolution have produced organism designs (DNA) which lead to the production of these different cell types (and many others) and also to their co-location. The result: the overall behavior of an organism. How and why this happened in nature is a mystery. For our software, though, it´s clear: functional and quality requirements needs to be fulfilled. So we as developers have to become “intelligent designers” of “software cells” which we put together to form a “software organism” which responds in satisfying ways to triggers from it´s environment. My bet is: If nature gets complex organisms working by following the PoMO, who are we to not apply this recipe for success to our much simpler “machines”? So my rule is: Wherever there is functionality to be delivered, because there is a clear Entry Point into software, design the functionality like nature would do it. Build it from mutually oblivious functional units. That´s what Flow Design is about. In that way it´s even universal, I´d say. Its notation can also be applied to biology: Never mind labeling the functional units with nouns. That´s ok in Flow Design. You´ll do that occassionally for functional units on a higher level of abstraction or when their purpose is close to hardware. Getting a cockroach to roam your bedroom takes 1,000,000 nerve cells (neurons). Getting the de-duplication program to do its job just takes 5 “software cells” (functional units). Both, though, follow the same basic principle. Translating functional units into code Moving from functional design to code is no rocket science. In fact it´s straightforward. There are two simple rules: Translate an input port to a function. Translate an output port either to a return statement in that function or to a function pointer visible to that function. The simplest translation of a functional unit is a function. That´s what you saw in the above example. Functions are mutually oblivious. That why Functional Programming likes them so much. It makes them composable. Which is the reason, nature works according to the PoMO. Let´s be clear about one thing: There is no dependency injection in nature. For all of an organism´s complexity no DI container is used. Behavior is the result of smooth cooperation between mutually oblivious building blocks. Functions will often be the adequate translation for the functional units in your designs. But not always. Take for example the case, where a processing step should not always produce an output. Maybe the purpose is to filter input. Here the functional unit consumes words and produces words. But it does not pass along every word flowing in. Some words are swallowed. Think of a spell checker. It probably should not check acronyms for correctness. There are too many of them. Or words with no more than two letters. Such words are called “stop words”. In the above picture the optionality of the output is signified by the astrisk outside the brackets. It means: Any number of (word) data items can flow from the functional unit for each input data item. It might be none or one or even more. This I call a stream of data. Such behavior cannot be translated into a function where output is generated with return. Because a function always needs to return a value. So the output port is translated into a function pointer or continuation which gets passed to the subroutine when called:[3]void filter_stop_words( string word, Action<string> onNoStopWord) { if (...check if not a stop word...) onNoStopWord(word); } If you want to be nitpicky you might call such a function pointer parameter an injection. And technically you´re right. Conceptually, though, it´s not an injection. Because the subroutine is not functionally dependent on the continuation. Firstly continuations are procedures, i.e. subroutines without a return type. Remember: Flow Design is about unidirectional data flow. Secondly the name of the formal parameter is chosen in a way as to not assume anything about downstream processing steps. onNoStopWord describes a situation (or event) within the functional unit only. Translating output ports into function pointers helps keeping functional units mutually oblivious in cases where output is optional or produced asynchronically. Either pass the function pointer to the function upon call. Or make it global by putting it on the encompassing class. Then it´s called an event. In C# that´s even an explicit feature.class Filter { public void filter_stop_words( string word) { if (...check if not a stop word...) onNoStopWord(word); } public event Action<string> onNoStopWord; } When to use a continuation and when to use an event dependens on how a functional unit is used in flows and how it´s packed together with others into classes. You´ll see examples further down the Flow Design road. Another example of 1D functional design Let´s see Flow Design once more in action using the visual notation. How about the famous word wrap kata? Robert C. Martin has posted a much cited solution including an extensive reasoning behind his TDD approach. So maybe you want to compare it to Flow Design. The function signature given is:string WordWrap(string text, int maxLineLength) {...} That´s not an Entry Point since we don´t see an application with an environment and users. Nevertheless it´s a function which is supposed to provide a certain functionality. The text passed in has to be reformatted. The input is a single line of arbitrary length consisting of words separated by spaces. The output should consist of one or more lines of a maximum length specified. If a word is longer than a the maximum line length it can be split in multiple parts each fitting in a line. Flow Design Let´s start by brainstorming the process to accomplish the feat of reformatting the text. What´s needed? Words need to be assembled into lines Words need to be extracted from the input text The resulting lines need to be assembled into the output text Words too long to fit in a line need to be split Does sound about right? I guess so. And it shows a kind of priority. Long words are a special case. So maybe there is a hint for an incremental design here. First let´s tackle “average words” (words not longer than a line). Here´s the Flow Design for this increment: The the first three bullet points turned into functional units with explicit data added. As the signature requires a text is transformed into another text. See the input of the first functional unit and the output of the last functional unit. In between no text flows, but words and lines. That´s good to see because thereby the domain is clearly represented in the design. The requirements are talking about words and lines and here they are. But note the asterisk! It´s not outside the brackets but inside. That means it´s not a stream of words or lines, but lists or sequences. For each text a sequence of words is output. For each sequence of words a sequence of lines is produced. The asterisk is used to abstract from the concrete implementation. Like with streams. Whether the list of words gets implemented as an array or an IEnumerable is not important during design. It´s an implementation detail. Does any processing step require further refinement? I don´t think so. They all look pretty “atomic” to me. And if not… I can always backtrack and refine a process step using functional design later once I´ve gained more insight into a sub-problem. Implementation The implementation is straightforward as you can imagine. The processing steps can all be translated into functions. Each can be tested easily and separately. Each has a focused responsibility. And the process flow becomes just a sequence of function calls: Easy to understand. It clearly states how word wrapping works - on a high level of abstraction. And it´s easy to evolve as you´ll see. Flow Design - Increment 2 So far only texts consisting of “average words” are wrapped correctly. Words not fitting in a line will result in lines too long. Wrapping long words is a feature of the requested functionality. Whether it´s there or not makes a difference to the user. To quickly get feedback I decided to first implement a solution without this feature. But now it´s time to add it to deliver the full scope. Fortunately Flow Design automatically leads to code following the Open Closed Principle (OCP). It´s easy to extend it - instead of changing well tested code. How´s that possible? Flow Design allows for extension of functionality by inserting functional units into the flow. That way existing functional units need not be changed. The data flow arrow between functional units is a natural extension point. No need to resort to the Strategy Pattern. No need to think ahead where extions might need to be made in the future. I just “phase in” the remaining processing step: Since neither Extract words nor Reformat know of their environment neither needs to be touched due to the “detour”. The new processing step accepts the output of the existing upstream step and produces data compatible with the existing downstream step. Implementation - Increment 2 A trivial implementation checking the assumption if this works does not do anything to split long words. The input is just passed on: Note how clean WordWrap() stays. The solution is easy to understand. A developer looking at this code sometime in the future, when a new feature needs to be build in, quickly sees how long words are dealt with. Compare this to Robert C. Martin´s solution:[4] How does this solution handle long words? Long words are not even part of the domain language present in the code. At least I need considerable time to understand the approach. Admittedly the Flow Design solution with the full implementation of long word splitting is longer than Robert C. Martin´s. At least it seems. Because his solution does not cover all the “word wrap situations” the Flow Design solution handles. Some lines would need to be added to be on par, I guess. But even then… Is a difference in LOC that important as long as it´s in the same ball park? I value understandability and openness for extension higher than saving on the last line of code. Simplicity is not just less code, it´s also clarity in design. But don´t take my word for it. Try Flow Design on larger problems and compare for yourself. What´s the easier, more straightforward way to clean code? And keep in mind: You ain´t seen all yet ;-) There´s more to Flow Design than described in this chapter. In closing I hope I was able to give you a impression of functional design that makes you hungry for more. To me it´s an inevitable step in software development. Jumping from requirements to code does not scale. And it leads to dirty code all to quickly. Some thought should be invested first. Where there is a clear Entry Point visible, it´s functionality should be designed using data flows. Because with data flows abstraction is possible. For more background on why that´s necessary read my blog article here. For now let me point out to you - if you haven´t already noticed - that Flow Design is a general purpose declarative language. It´s “programming by intention” (Shalloway et al.). Just write down how you think the solution should work on a high level of abstraction. This breaks down a large problem in smaller problems. And by following the PoMO the solutions to those smaller problems are independent of each other. So they are easy to test. Or you could even think about getting them implemented in parallel by different team members. Flow Design not only increases evolvability, but also helps becoming more productive. All team members can participate in functional design. This goes beyon collective code ownership. We´re talking collective design/architecture ownership. Because with Flow Design there is a common visual language to talk about functional design - which is the foundation for all other design activities.   PS: If you like what you read, consider getting my ebook “The Incremental Architekt´s Napkin”. It´s where I compile all the articles in this series for easier reading. I like the strictness of Function Programming - but I also find it quite hard to live by. And it certainly is not what millions of programmers are used to. Also to me it seems, the real world is full of state and side effects. So why give them such a bad image? That´s why functional design takes a more pragmatic approach. State and side effects are ok for processing steps - but be sure to follow the SRP. Don´t put too much of it into a single processing step. ? Image taken from www.physioweb.org ? My code samples are written in C#. C# sports typed function pointers called delegates. Action is such a function pointer type matching functions with signature void someName(T t). Other languages provide similar ways to work with functions as first class citizens - even Java now in version 8. I trust you find a way to map this detail of my translation to your favorite programming language. I know it works for Java, C++, Ruby, JavaScript, Python, Go. And if you´re using a Functional Programming language it´s of course a no brainer. ? Taken from his blog post “The Craftsman 62, The Dark Path”. ?

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  • The Incremental Architect&acute;s Napkin - #1 - It&acute;s about the money, stupid

    - by Ralf Westphal
    Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/05/24/the-incremental-architectacutes-napkin---1---itacutes-about-the.aspx Software development is an economic endeavor. A customer is only willing to pay for value. What makes a software valuable is required to become a trait of the software. We as software developers thus need to understand and then find a way to implement requirements. Whether or in how far a customer really can know beforehand what´s going to be valuable for him/her in the end is a topic of constant debate. Some aspects of the requirements might be less foggy than others. Sometimes the customer does not know what he/she wants. Sometimes he/she´s certain to want something - but then is not happy when that´s delivered. Nevertheless requirements exist. And developers will only be paid if they deliver value. So we better focus on doing that. Although is might sound trivial I think it´s important to state the corollary: We need to be able to trace anything we do as developers back to some requirement. You decide to use Go as the implementation language? Well, what´s the customer´s requirement this decision is linked to? You decide to use WPF as the GUI technology? What´s the customer´s requirement? You decide in favor of a layered architecture? What´s the customer´s requirement? You decide to put code in three classes instead of just one? What´s the customer´s requirement behind that? You decide to use MongoDB over MySql? What´s the customer´s requirement behind that? etc. I´m not saying any of these decisions are wrong. I´m just saying whatever you decide be clear about the requirement that´s driving your decision. You have to be able to answer the question: Why do you think will X deliver more value to the customer than the alternatives? Customers are not interested in romantic ideals of hard working, good willing, quality focused craftsmen. They don´t care how and why you work - as long as what you deliver fulfills their needs. They want to trust you to recognize this as your top priority - and then deliver. That´s all. Fundamental aspects of requirements If you´re like me you´re probably not used to such scrutinization. You want to be trusted as a professional developer - and decide quite a few things following your gut feeling. Or by relying on “established practices”. That´s ok in general and most of the time - but still… I think we should be more conscious about our decisions. Which would make us more responsible, even more professional. But without further guidance it´s hard to reason about many of the myriad decisions we´ve to make over the course of a software project. What I found helpful in this situation is structuring requirements into fundamental aspects. Instead of one large heap of requirements then there are smaller blobs. With them it´s easier to check if a decisions falls in their scope. Sure, every project has it´s very own requirements. But all of them belong to just three different major categories, I think. Any requirement either pertains to functionality, non-functional aspects or sustainability. For short I call those aspects: Functionality, because such requirements describe which transformations a software should offer. For example: A calculator software should be able to add and multiply real numbers. An auction website should enable you to set up an auction anytime or to find auctions to bid for. Quality, because such requirements describe how functionality is supposed to work, e.g. fast or secure. For example: A calculator should be able to calculate the sinus of a value much faster than you could in your head. An auction website should accept bids from millions of users. Security of Investment, because functionality and quality need not just be delivered in any way. It´s important to the customer to get them quickly - and not only today but over the course of several years. This aspect introduces time into the “requrements equation”. Security of Investments (SoI) sure is a non-functional requirement. But I think it´s important to not subsume it under the Quality (Q) aspect. That´s because SoI has quite special properties. For one, SoI for software means something completely different from what it means for hardware. If you buy hardware (a car, a hair blower) you find that a worthwhile investment, if the hardware does not change it´s functionality or quality over time. A car still running smoothly with hardly any rust spots after 10 years of daily usage would be a very secure investment. So for hardware (or material products, if you like) “unchangeability” (in the face of usage) is desirable. With software you want the contrary. Software that cannot be changed is a waste. SoI for software means “changeability”. You want to be sure that the software you buy/order today can be changed, adapted, improved over an unforseeable number of years so as fit changes in its usage environment. But that´s not the only reason why the SoI aspect is special. On top of changeability[1] (or evolvability) comes immeasurability. Evolvability cannot readily be measured by counting something. Whether the changeability is as high as the customer wants it, cannot be determined by looking at metrics like Lines of Code or Cyclomatic Complexity or Afferent Coupling. They may give a hint… but they are far, far from precise. That´s because of the nature of changeability. It´s different from performance or scalability. Also it´s because a customer cannot tell upfront, “how much” evolvability he/she wants. Whether requirements regarding Functionality (F) and Q have been met, a customer can tell you very quickly and very precisely. A calculation is missing, the calculation takes too long, the calculation time degrades with increased load, the calculation is accessible to the wrong users etc. That´s all very or at least comparatively easy to determine. But changeability… That´s a whole different thing. Nevertheless over time the customer will develop a feedling if changeability is good enough or degrading. He/she just has to check the development of the frequency of “WTF”s from developers ;-) F and Q are “timeless” requirement categories. Customers want us to deliver on them now. Just focusing on the now, though, is rarely beneficial in the long run. So SoI adds a counterweight to the requirements picture. Customers want SoI - whether they know it or not, whether they state if explicitly or not. In closing A customer´s requirements are not monolithic. They are not all made the same. Rather they fall into different categories. We as developers need to recognize these categories when confronted with some requirement - and take them into account. Only then can we make true professional decisions, i.e. conscious and responsible ones. I call this fundamental trait of software “changeability” and not “flexibility” to distinguish to whom it´s a concern. “Flexibility” to me means, software as is can easily be adapted to a change in its environment, e.g. by tweaking some config data or adding a library which gets picked up by a plug-in engine. “Flexibiltiy” thus is a matter of some user. “Changeability”, on the other hand, to me means, software can easily be changed in its structure to adapt it to new requirements. That´s a matter of the software developer. ?

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  • The Incremental Architect&acute;s Napkin - #2 - Balancing the forces

    - by Ralf Westphal
    Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/06/02/the-incremental-architectacutes-napkin---2---balancing-the-forces.aspxCategorizing requirements is the prerequisite for ecconomic architectural decisions. Not all requirements are created equal. However, to truely understand and describe the requirement forces pulling on software development, I think further examination of the requirements aspects is varranted. Aspects of Functionality There are two sides to Functionality requirements. It´s about what a software should do. I call that the Operations it implements. Operations are defined by expressions and control structures or calls to frameworks of some sort, i.e. (business) logic statements. Operations calculate, transform, aggregate, validate, send, receive, load, store etc. Operations are about behavior; they take input and produce output by considering state. I´m not using the term “function” here, because functions - or methods or sub-programs - are not necessary to implement Operations. Functions belong to a different sub-aspect of requirements (see below). Operations alone are not enough, though, to make a customer happy with regard to his/her Functionality requirements. Only correctly implemented Operations provide full value. This should make clear, why testing is so important. And not just manual tests during development of some operational feature, but automated tests. Because only automated tests scale when over time the number of operations increases. Without automated tests there is no guarantee formerly correct operations are still correct after more got added. To retest all previous operations manually is infeasible. So whoever relies just on manual tests is not really balancing the two forces Operations and Correctness. With manual tests more weight is put on the side of the scale of Operations. That might be ok for a short period of time - but in the long run it will bite you. You need to plan for Correctness in the long run from the first day of your project on. Aspects of Quality As important as Functionality is, it´s not the driver for software development. No software has ever been written to just implement some operation in code. We don´t need computers just to do something. All computers can do with software we can do without them. Well, at least given enough time and resources. We could calculate the most complex formulas without computers. We could do auctions with millions of people without computers. The only reason we want computers to help us with this and a million other Operations is… We don´t want to wait for the results very long. Or we want less errors. Or we want easier accessability to complicated solutions. So the main reason for customers to buy/order software is some Quality. They want some Functionality with a higher Quality (e.g. performance, scalability, usability, security…) than without the software. But Qualities come in at least two flavors: Most important are Primary Qualities. That´s the Qualities software truely is written for. Take an online auction website for example. Its Primary Qualities are performance, scalability, and usability, I´d say. Auctions should come within reach of millions of people; setting up an auction should be very easy; finding a suitable auction and bidding on it should be as fast as possible. Only if those Qualities have been implemented does security become relevant. A secure auction website is important - but not as important as a fast auction website. Nobody would want to use the most secure auction website if it was unbearably slow. But there would be people willing to use the fastest auction website even it was lacking security. That´s why security - with regard to online auction software - is not a Primary Quality, but just a Secondary Quality. It´s a supporting quality, so to speak. It does not deliver value by itself. With a password manager software this might be different. There security might be a Primary Quality. Please get me right: I don´t want to denigrate any Quality. There´s a long list of non-functional requirements at Wikipedia. They are all created equal - but that does not mean they are equally important for all software projects. When confronted with Quality requirements check with the customer which are primary and which are secondary. That will help to make good economical decisions when in a crunch. Resources are always limited - but requirements are a bottomless ocean. Aspects of Security of Investment Functionality and Quality are traditionally the requirement aspects cared for most - by customers and developers alike. Even today, when pressure rises in a project, tunnel vision will focus on them. Any measures to create and hold up Security of Investment (SoI) will be out of the window pretty quickly. Resistance to customers and/or management is futile. As long as SoI is not placed on equal footing with Functionality and Quality it´s bound to suffer under pressure. To look closer at what SoI means will help to become more conscious about it and make customers and management aware of the risks of neglecting it. SoI to me has two facets: Production Efficiency (PE) is about speed of delivering value. Customers like short response times. Short response times mean less money spent. So whatever makes software development faster supports this requirement. This must not lead to duct tape programming and banging out features by the dozen, though. Because customers don´t just want Operations and Quality, but also Correctness. So if Correctness gets compromised by focussing too much on Production Efficiency it will fire back. Customers want PE not just today, but over the whole course of a software´s lifecycle. That means, it´s not just about coding speed, but equally about code quality. If code quality leads to rework the PE is on an unsatisfactory level. Also if code production leads to waste it´s unsatisfactory. Because the effort which went into waste could have been used to produce value. Rework and waste cost money. Rework and waste abound, however, as long as PE is not addressed explicitly with management and customers. Thanks to the Agile and Lean movements that´s increasingly the case. Nevertheless more could and should be done in many teams. Each and every developer should keep in mind that Production Efficiency is as important to the customer as Functionality and Quality - whether he/she states it or not. Making software development more efficient is important - but still sooner or later even agile projects are going to hit a glas ceiling. At least as long as they neglect the second SoI facet: Evolvability. Delivering correct high quality functionality in short cycles today is good. But not just any software structure will allow this to happen for an indefinite amount of time.[1] The less explicitly software was designed the sooner it´s going to get stuck. Big ball of mud, monolith, brownfield, legacy code, technical debt… there are many names for software structures that have lost the ability to evolve, to be easily changed to accomodate new requirements. An evolvable code base is the opposite of a brownfield. It´s code which can be easily understood (by developers with sufficient domain expertise) and then easily changed to accomodate new requirements. Ideally the costs of adding feature X to an evolvable code base is independent of when it is requested - or at least the costs should only increase linearly, not exponentially.[2] Clean Code, Agile Architecture, and even traditional Software Engineering are concerned with Evolvability. However, it seems no systematic way of achieving it has been layed out yet. TDD + SOLID help - but still… When I look at the design ability reality in teams I see much room for improvement. As stated previously, SoI - or to be more precise: Evolvability - can hardly be measured. Plus the customer rarely states an explicit expectation with regard to it. That´s why I think, special care must be taken to not neglect it. Postponing it to some large refactorings should not be an option. Rather Evolvability needs to be a core concern for every single developer day. This should not mean Evolvability is more important than any of the other requirement aspects. But neither is it less important. That´s why more effort needs to be invested into it, to bring it on par with the other aspects, which usually are much more in focus. In closing As you see, requirements are of quite different kinds. To not take that into account will make it harder to understand the customer, and to make economic decisions. Those sub-aspects of requirements are forces pulling in different directions. To improve performance might have an impact on Evolvability. To increase Production Efficiency might have an impact on security etc. No requirement aspect should go unchecked when deciding how to allocate resources. Balancing should be explicit. And it should be possible to trace back each decision to a requirement. Why is there a null-check on parameters at the start of the method? Why are there 5000 LOC in this method? Why are there interfaces on those classes? Why is this functionality running on the threadpool? Why is this function defined on that class? Why is this class depending on three other classes? These and a thousand more questions are not to mean anything should be different in a code base. But it´s important to know the reason behind all of these decisions. Because not knowing the reason possibly means waste and having decided suboptimally. And how do we ensure to balance all requirement aspects? That needs practices and transparency. Practices means doing things a certain way and not another, even though that might be possible. We´re dealing with dangerous tools here. Like a knife is a dangerous tool. Harm can be done if we use our tools in just any way at the whim of the moment. Over the centuries rules and practices have been established how to use knifes. You don´t put them in peoples´ legs just because you´re feeling like it. You hand over a knife with the handle towards the receiver. You might not even be allowed to cut round food like potatos or eggs with it. The same should be the case for dangerous tools like object-orientation, remote communication, threads etc. We need practices to use them in a way so requirements are balanced almost automatically. In addition, to be able to work on software as a team we need transparency. We need means to share our thoughts, to work jointly on mental models. So far our tools are focused on working with code. Testing frameworks, build servers, DI containers, intellisense, refactoring support… That´s all nice and well. I don´t want to miss any of that. But I think it´s not enough. We´re missing mental tools, tools for making thinking and talking about software (independently of code) easier. You might think, enough of such tools already exist like all those UML diagram types or Flow Charts. But then, isn´t it strange, hardly any team is using them to design software? Or is that just due to a lack of education? I don´t think so. It´s a matter value/weight ratio: the current mental tools are too heavy weight compared to the value they deliver. So my conclusion is, we need lightweight tools to really be able to balance requirements. Software development is complex. We need guidance not to forget important aspects. That´s like with flying an airplane. Pilots don´t just jump in and take off for their destination. Yes, there are times when they are “flying by the seats of their pants”, when they are just experts doing thing intuitively. But most of the time they are going through honed practices called checklist. See “The Checklist Manifesto” for very enlightening details on this. Maybe then I should say it like this: We need more checklists for the complex businss of software development.[3] But that´s what software development mostly is about: changing software over an unknown period of time. It needs to be corrected in order to finally provide promised operations. It needs to be enhanced to provide ever more operations and qualities. All this without knowing when it´s going to stop. Probably never - until “maintainability” hits a wall when the technical debt is too large, the brownfield too deep. Software development is not a sprint, is not a marathon, not even an ultra marathon. Because to all this there is a foreseeable end. Software development is like continuously and foreever running… ? And sometimes I dare to think that costs could even decrease over time. Think of it: With each feature a software becomes richer in functionality. So with each additional feature the chance of there being already functionality helping its implementation increases. That should lead to less costs of feature X if it´s requested later than sooner. X requested later could stand on the shoulders of previous features. Alas, reality seems to be far from this despite 20+ years of admonishing developers to think in terms of reusability.[1] ? Please don´t get me wrong: I don´t want to bog down the “art” of software development with heavyweight practices and heaps of rules to follow. The framework we need should be lightweight. It should not stand in the way of delivering value to the customer. It´s purpose is even to make that easier by helping us to focus and decreasing waste and rework. ?

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  • Flaws in my PHP development setup - sharing sources causing lags

    - by Wiktor
    I have following development setup for my PHP projects: Working station running on Windows 7 with PhpStorm IDE. GIT for version controlling. CentOS on virtual machine (VirtualBox) with Apache and MySQL (copy of production server). So far, I've been sharing project's source folders between host and guest systems and it was working quite well only really slow. The reason behind this is that Apache was reading files from remote folder (mounted locally). After doing some research, I found out that this set up can be improved by using disk mapping (Samba) instead of folder sharing. So I did that change. I configured my PhpStorm to automatically deploy files to mapped drive. Everything works like a charm now, except for one problem - when I change branches I need to synchronize project's local folder with the one on mapped drive and that takes time, a lot of time (like branching in SVN). Is there another way to handle this than just working on files directly on mapped drive?

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  • In Enterprise Architect I modified an interface, how to update the realizing classes?

    - by Timo
    I've created an interface in a class model. This interface has two methods, A and B and method A takes an argument (a) and method B does not take an argument (yet). Additionally I've created a class that implements this interface, overriding both methods. After a discussing the model method B now should also take a parameter (b), so I modified the interface to reflect this change. However the class realizing this interface is not updated automatically. For one class it's possible to add the method by re-creating the link between the interface, specify the which method should be implemented and deleting this link again. Then the OLD method signature has to be removed as well. This is a lot of work if there is more then one class implementing the modified interface, not to mention error-prone. Does anybody know how to make an entire class model update this type of dependency?

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  • Podcast Show Notes: Architect Meet-Up

    - by Bob Rhubart
    What happens when you get bunch of architects together and just let them talk? The latest ArchBeat Podcast features just such a conversation. The four participants in this conversation responded to a general invitation to my list of some three dozen Usual Suspects to join me on Skype for what I call a virtual meet-up. That conversation took place on March 20, 2012. The Participants Basheer Khan: Oracle ACE Director; Founder, President & CEO at Innowave Technology Lucas Jellema: Oracle ACE Director; CTO of AMIS Services Eric Stephens: a director of Enterprise Architecture at Oracle Derek Sharpe: director of Oracle’s Fusion Middleware Architecture Team The Conversation Listen to Part 1: Meeting the Mobile Challenge The conversation focuses on Oracle ADF Mobile and the challenges of defining a mobile strategy for the enterprise. Listen to Part 2: Mobile Security, Availability, and Usability (April 4) The conversation turns to the security, availability, and usability challenges in the evolution of the mobile enterprise. Listen to Part 3 Evolving Software Development Roles (April 11) The panel closes out the discussion with a look at the interplay between developers and architects, and the evolving nature of both roles.

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  • Welcome to ubiquitous file sharing (December 08, 2009)

    - by user12612012
    The core of any file server is its file system and ZFS provides the foundation on which we have built our ubiquitous file sharing and single access control model.  ZFS has a rich, Windows and NFSv4 compatible, ACL implementation (ZFS only uses ACLs), it understands both UNIX IDs and Windows SIDs and it is integrated with the identity mapping service; it knows when a UNIX/NIS user and a Windows user are equivalent, and similarly for groups.  We have a single access control architecture, regardless of whether you are accessing the system via NFS or SMB/CIFS.The NFS and SMB protocol services are also integrated with the identity mapping service and shares are not restricted to UNIX permissions or Windows permissions.  All access control is performed by ZFS, the system can always share file systems simultaneously over both protocols and our model is native access to any share from either protocol.Modal architectures have unnecessary restrictions, confusing rules, administrative overhead and weird deployments to try to make them work; they exist as a compromise not because they offer a benefit.  Having some shares that only support UNIX permissions, others that only support ACLs and some that support both in a quirky way really doesn't seem like the sort of thing you'd want in a multi-protocol file server.  Perhaps because the server has been built on a file system that was designed for UNIX permissions, possibly with ACL support bolted on as an add-on afterthought, or because the protocol services are not truly integrated with the operating system, it may not be capable of supporting a single integrated model.With a single, integrated sharing and access control model: If you connect from Windows or another SMB/CIFS client: The system creates a credential containing both your Windows identity and your UNIX/NIS identity.  The credential includes UNIX/NIS IDs and SIDs, and UNIX/NIS groups and Windows groups. If your Windows identity is mapped to an ephemeral ID, files created by you will be owned by your Windows identity (ZFS understands both UNIX IDs and Windows SIDs). If your Windows identity is mapped to a real UNIX/NIS UID, files created by you will be owned by your UNIX/NIS identity. If you access a file that you previously created from UNIX, the system will map your UNIX identity to your Windows identity and recognize that you are the owner.  Identity mapping also supports access checking if you are being assessed for access via the ACL. If you connect via NFS (typically from a UNIX client): The system creates a credential containing your UNIX/NIS identity (including groups). Files you create will be owned by your UNIX/NIS identity. If you access a file that you previously created from Windows and the file is owned by your UID, no mapping is required. Otherwise the system will map your Windows identity to your UNIX/NIS identity and recognize that you are the owner.  Again, mapping is fully supported during ACL processing. The NFS, SMB/CIFS and ZFS services all work cooperatively to ensure that your UNIX identity and your Windows identity are equivalent when you access the system.  This, along with the single ACL-based access control implementation, results in a system that provides that elusive ubiquitous file sharing experience.

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  • My wireless has suddenly became disabled by hardware switch, BIOS, rfkill, fn+f8 do nothing

    - by cwwk
    I have a toshiba l655d-s5145. There is no physical toggle for the wireless, although the f8 key is supposed to do the trick. It doesn't. The wireless has been working since October, and suddenly, nothing. RFKILL reports that the wireless is hard blocked, but unblock wifi, unblock 0, unblock all do nothing. I inserted a usb dongle, and that is also disabled by hardware switch, although rfkill reports that it is neither hard nor soft blocked. My onboard wireless is 02:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8188CE 802.11b/g/n WiFi Adapter (rev 01) according to lspci. Lsmod reports that these drivers are loaded. rtl8192c_common 75767 1 rtl8192ce rtlwifi 110972 1 rtl8192ce I resorted to reformatting the drive and reinstalling, but that also did not work. In BIOS I restored system defaults as there is no specific entry for wifi. Before reinstalling a pure xubuntu I went into Unity and saw that the airplane mode was on and despite being toggled off, it returned to the on position. I'm not sure where to find airplane mode in Xubuntu. What else can I do? I need my wireless.

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  • how to architect this to make it unit testable

    - by SOfanatic
    I'm currently working on a project where I'm receiving an object via web service (WSDL). The overall process is the following: Receive object - add/delete/update parts (or all) of it - and return the object with the changes made. The thing is that sometimes these changes are complicated and there is some logic involved, other databases, other web services, etc. so to facilitate this I'm creating a custom object that mimics the original one but has some enhanced functionality to make some things easier. So I'm trying to have this process: Receive original object - convert/copy it to custom object - add/delete/update - convert/copy it back to original object - return original object. Example: public class Row { public List<Field> Fields { get; set; } public string RowId { get; set; } public Row() { this.Fields = new List<Field>(); } } public class Field { public string Number { get; set; } public string Value { get; set; } } So for example, one of the "actions" to perform on this would be to find all Fields in a Row that match a Value equal to something, and update them with some other value. I have a CustomRow class that represents the Row class, how can I make this class unit testable? Do I have to create an interface ICustomRow to mock it in the unit test? If one of the actions is to sum all of the Values in the Fields that have a Number equal to 10, like this function, how can design the custom class to facilitate unit tests. Sample function: public int Sum(FieldNumber number) { return row.Fields.Where(x => x.FieldNumber.Equals(number)).Sum(x => x.FieldValue); } Am I approaching this the wrong way?

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