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• Waterfall Model (SDLC) vs. Prototyping Model

  The characters in the fable of the Tortoise and the Hare can easily be used to demonstrate the similarities and differences between the Waterfall and Prototyping software development models. This children fable is about a race between a consistently slow moving but steadfast turtle and an extremely fast but unreliable rabbit. After closely comparing each character’s attributes in correlation with both software development models, a trend seems to appear in that the Waterfall closely resembles the Tortoise in that Waterfall Model is typically a slow moving process that is broken up in to multiple sequential steps that must be executed in a standard linear pattern. The Tortoise can be quoted several times in the story saying “Slow and steady wins the race.” This is the perfect mantra for the Waterfall Model in that this model is seen as a cumbersome and slow moving. Waterfall Model Phases Requirement Analysis & Definition This phase focuses on defining requirements for a project that is to be developed and determining if the project is even feasible. Requirements are collected by analyzing existing systems and functionality in correlation with the needs of the business and the desires of the end users. The desired output for this phase is a list of specific requirements from the business that are to be designed and implemented in the subsequent steps. In addition this phase is used to determine if any value will be gained by completing the project. System Design This phase focuses primarily on the actual architectural design of a system, and how it will interact within itself and with other existing applications. Projects at this level should be viewed at a high level so that actual implementation details are decided in the implementation phase. However major environmental decision like hardware and platform decision are typically decided in this phase. Furthermore the basic goal of this phase is to design an application at the system level in those classes, interfaces, and interactions are defined. Additionally decisions about scalability, distribution and reliability should also be considered for all decisions. The desired output for this phase is a functional  design document that states all of the architectural decisions that have been made in regards to the project as well as a diagrams like a sequence and class diagrams. Software Design This phase focuses primarily on the refining of the decisions found in the functional design document. Classes and interfaces are further broken down in to logical modules based on the interfaces and interactions previously indicated. The output of this phase is a formal design document. Implementation / Coding This phase focuses primarily on implementing the previously defined modules in to units of code. These units are developed independently are intergraded as the system is put together as part of a whole system. Software Integration & Verification This phase primarily focuses on testing each of the units of code developed as well as testing the system as a whole. There are basic types of testing at this phase and they include: Unit Test and Integration Test. Unit Test are built to test the functionality of a code unit to ensure that it preforms its desired task. Integration testing test the system as a whole because it focuses on results of combining specific units of code and validating it against expected results. The output of this phase is a test plan that includes test with expected results and actual results. System Verification This phase primarily focuses on testing the system as a whole in regards to the list of project requirements and desired operating environment. Operation & Maintenance his phase primarily focuses on handing off the competed project over to the customer so that they can verify that all of their requirements have been met based on their original requirements. This phase will also validate the correctness of their requirements and if any changed need to be made. In addition, any problems not resolved in the previous phase will be handled in this section. The Waterfall Model’s linear and sequential methodology does offer a project certain advantages and disadvantages. Advantages of the Waterfall Model Simplistic to implement and execute for projects and/or company wide Limited demand on resources Large emphasis on documentation Disadvantages of the Waterfall Model Completed phases cannot be revisited regardless if issues arise within a project Accurate requirement are never gather prior to the completion of the requirement phase due to the lack of clarification in regards to client’s desires. Small changes or errors that arise in applications may cause additional problems The client cannot change any requirements once the requirements phase has been completed leaving them no options for changes as they see their requirements changes as the customers desires change. Excess documentation Phases are cumbersome and slow moving Learn more about the Major Process in the Sofware Development Life Cycle and Waterfall Model. Conversely, the Hare shares similar traits with the prototyping software development model in that ideas are rapidly converted to basic working examples and subsequent changes are made to quickly align the project with customers desires as they are formulated and as software strays from the customers vision. The basic concept of prototyping is to eliminate the use of well-defined project requirements. Projects are allowed to grow as the customer needs and request grow. Projects are initially designed according to basic requirements and are refined as requirement become more refined. This process allows customer to feel their way around the application to ensure that they are developing exactly what they want in the application This model also works well for determining the feasibility of certain approaches in regards to an application. Prototypes allow for quickly developing examples of implementing specific functionality based on certain techniques. Advantages of Prototyping Active participation from users and customers Allows customers to change their mind in specifying requirements Customers get a better understanding of the system as it is developed Earlier bug/error detection Promotes communication with customers Prototype could be used as final production Reduced time needed to develop applications compared to the Waterfall method Disadvantages of Prototyping Promotes constantly redefining project requirements that cause major system rewrites Potential for increased complexity of a system as scope of the system expands Customer could believe the prototype as the working version. Implementation compromises could increase the complexity when applying updates and or application fixes When companies trying to decide between the Waterfall model and Prototype model they need to evaluate the benefits and disadvantages for both models. Typically smaller companies or projects that have major time constraints typically head for more of a Prototype model approach because it can reduce the time needed to complete the project because there is more of a focus on building a project and less on defining requirements and scope prior to the start of a project. On the other hand, Companies with well-defined requirements and time allowed to generate proper documentation should steer towards more of a waterfall model because they are in a position to obtain clarified requirements and have to design and optimal solution prior to the start of coding on a project.

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• SQL SERVER – Windows File/Folder and Share Permissions – Notes from the Field #029

  - by Pinal Dave

  [Note from Pinal]: This is a 29th episode of Notes from the Field series. Security is the task which we should give it to the experts. If there is a small overlook or misstep, there are good chances that security of the organization is compromised. This is very true, but there are always devils’s advocates who believe everyone should know the security. As a DBA and Administrator, I often see people not taking interest in the Windows Security hiding behind the reason of not expert of Windows Server. We all often miss the important mission statement for the success of any organization – Teamwork. In this blog post Brian tells the story in very interesting lucid language. Read On! In this episode of the Notes from the Field series database expert Brian Kelley explains a very crucial issue DBAs and Developer faces on their production server. Linchpin People are database coaches and wellness experts for a data driven world. Read the experience of Brian in his own words. When I talk security among database professionals, I find that most have at least a working knowledge of how to apply security within a database. When I talk with DBAs in particular, I find that most have at least a working knowledge of security at the server level if we’re speaking of SQL Server. One area I see continually that is weak is in the area of Windows file/folder (NTFS) and share permissions. The typical response is, “I’m a database developer and the Windows system administrator is responsible for that.” That may very well be true – the system administrator may have the primary responsibility and accountability for file/folder and share security for the server. However, if you’re involved in the typical activities surrounding databases and moving data around, you should know these permissions, too. Otherwise, you could be setting yourself up where someone is able to get to data he or she shouldn’t, or you could be opening the door where human error puts bad data in your production system. File/Folder Permission Basics: I wrote about file/folder permissions a few years ago to give the basic permissions that are most often seen. Here’s what you must know as a minimum at the file/folder level: Read - Allows you to read the contents of the file or folder. Having read permissions allows you to copy the file or folder. Write  – Again, as the name implies, it allows you to write to the file or folder. This doesn’t include the ability to delete, however, nothing stops a person with this access from writing an empty file. Delete - Allows the file/folder to be deleted. If you overwrite files, you may need this permission. Modify - Allows read, write, and delete. Full Control - Same as modify + the ability to assign permissions. File/Folder permissions aggregate, unless there is a DENY (where it trumps, just like within SQL Server), meaning if a person is in one group that gives Read and antoher group that gives Write, that person has both Read and Write permissions. As you might expect me to say, always apply the Principle of Least Privilege. This likely means that any additional permission you might add does not need Full Control. Share Permission Basics: At the share level, here are the permissions. Read - Allows you to read the contents on the share. Change - Allows you to read, write, and delete contents on the share. Full control - Change + the ability to modify permissions. Like with file/folder permissions, these permissions aggregate, and DENY trumps. So What Access Does a Person / Process Have? Figuring out what someone or some process has depends on how the location is being accessed: Access comes through the share (\\ServerName\Share) – a combination of permissions is considered. Access is through a drive letter (C:\, E:\, S:\, etc.) – only the file/folder permissions are considered. The only complicated one here is access through the share. Here’s what Windows does: Figures out what the aggregated permissions are at the file/folder level. Figures out what the aggregated permissions are at the share level. Takes the most restrictive of the two sets of permissions. You can test this by granting Full Control over a folder (this is likely already in place for the Users local group) and then setting up a share. Give only Read access through the share, and that includes to Administrators (if you’re creating a share, likely you have membership in the Administrators group). Try to read a file through the share. Now try to modify it. The most restrictive permission is the Share level permissions. It’s set to only allow Read. Therefore, if you come through the share, it’s the most restrictive. Does This Knowledge Really Help Me? In my experience, it does. I’ve seen cases where sensitive files were accessible by every authenticated user through a share. Auditors, as you might expect, have a real problem with that. I’ve also seen cases where files to be imported as part of the nightly processing were overwritten by files intended from development. And I’ve seen cases where a process can’t get to the files it needs for a process because someone changed the permissions. If you know file/folder and share permissions, you can spot and correct these types of security flaws. Given that there are a lot of database professionals that don’t understand these permissions, if you know it, you set yourself apart. And if you’re able to help on critical processes, you begin to set yourself up as a linchpin (link to .pdf) for your organization. If you want to get started with performance tuning and database security with the help of experts, read more over at Fix Your SQL Server. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: Notes from the Field, PostADay, SQL, SQL Authority, SQL Query, SQL Security, SQL Server, SQL Tips and Tricks, T SQL

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• PASS: Election Changes for 2011

  - by Bill Graziano

  Last year after the election, the PASS Board created an Election Review Committee.  This group was charged with reviewing our election procedures and making suggestions to improve the process.  You can read about the formation of the group and review some of the intermediate work on the site – especially in the forums. I was one of the members of the group along with Joe Webb (Chair), Lori Edwards, Brian Kelley, Wendy Pastrick, Andy Warren and Allen White.  This group worked from October to April on our election process.  Along the way we: Interviewed interested parties including former NomCom members, Board candidates and anyone else that came forward. Held a session at the Summit to allow interested parties to discuss the issues Had numerous conference calls and worked through the various topics I can’t thank these people enough for the work they did.  They invested a tremendous number of hours thinking, talking and writing about our elections.  I’m proud to say I was a member of this group and thoroughly enjoyed working with everyone (even if I did finally get tired of all the calls.) The ERC delivered their recommendations to the PASS Board prior to our May Board meeting.  We reviewed those and made a few modifications.  I took their recommendations and rewrote them as procedures while incorporating those changes.  Their original recommendations as well as our final document are posted at the ERC documents page.  Please take a second and read them BEFORE we start the elections.  If you have any questions please post them in the forums on the ERC site. (My final document includes a change log at the end that I decided to leave in.  If you want to know which areas to pay special attention to that’s a good start.) Many of those recommendations were already posted in the forums or in the blogs of individual ERC members.  Hopefully nothing in the ERC document is too surprising. In this post I’m going to walk through some of the key changes and talk about what I remember from both ERC and Board discussions.  I’ll pay a little extra attention to things the Board changed from the ERC.  I’d also encourage any of the Board or ERC members to blog their thoughts on this. The Nominating Committee will continue to exist.  Personally, I was curious to see what the non-Board ERC members would think about the NomCom.  There was broad agreement that a group to vet candidates had value to the organization. The NomCom will be composed of five members.  Two will be Board members and three will be from the membership at large.  The only requirement for the three community members is that you’ve volunteered in some way (and volunteering is defined very broadly).  We expect potential at-large NomCom members to participate in a forum on the PASS site to answer questions from the other PASS members. We’re going to hold an election to determine the three community members.  It will be closer to voting for Summit sessions than voting for Board members.  That means there won’t be multiple dedicated emails.  If you’re at all paying attention it will be easy to participate.  Personally I wanted it easy for those that cared to participate but not overwhelm those that didn’t care.  I think this strikes a good balance. There’s also a clause that in order to be considered a winner in this NomCom election, you must receive 10 votes.  This is something I suggested.  I have no idea how popular the NomCom election is going to be.  I just wanted a fallback that if no one participated and some random person got in with one or two votes.  Any open slots will be filled by the NomCom chair (usually the PASS Immediate Past President).  My assumption is that they would probably take the next highest vote getters unless they were throwing flames in the forums or clearly unqualified.  As a final check, the Board still approves the final NomCom. The NomCom is going to rank candidates instead of rating them.  This has interesting implications.  This was championed by another ERC member and I’m hoping they write something about it.  This will really force the NomCom to make decisions between candidates.  You can’t just rate everyone a 3 and be done with it.  It may also make candidates appear further apart than they actually are.  I’m looking forward talking with the NomCom after this election and getting their feedback on this. The PASS Board added an option to remove a candidate with a unanimous vote of the NomCom.  This was primarily put in place to handle people that lied on their application or had a criminal background or some other unusual situation and we figured it out. We list an explicit goal of three candidate per open slot. We also wanted an easy way to find the NomCom candidate rankings from the ballot.  Hopefully this will satisfy those that want a broad candidate pool and those that want the NomCom to identify the most qualified candidates. The primary spokesperson for the NomCom is the committee chair.  After the issues around the election last year we didn’t have a good communication plan in place.  We should have and that was a failure on the part of the Board.  If there is criticism of the election this year I hope that falls squarely on the Board.  The community members of the NomCom shouldn’t be fielding complaints over the election process.  That said, the NomCom is ranking candidates and we are forcing them to rank some lower than others.  I’m sure you’ll each find someone that you think should have been ranked differently.  I also want to highlight one other change to the process that we started last year and isn’t included in these documents.  I think the candidate forums on the PASS site were tremendously helpful last year in helping people to find out more about candidates.  That gives our members a way to ask hard questions of the candidates and publicly see their answers. This year we have two important groups to fill.  The first is the NomCom.  We need three people from our membership to step up and fill this role.  It won’t be easy.  You will have to make subjective rankings of your fellow community members.  Your actions will be important in deciding who the future leaders of PASS will be.  There’s a 50/50 chance that one of the people you interview will be the President of PASS someday.  This is not a responsibility to be taken lightly. The second is the slate of candidates.  If you’ve ever thought about running for the Board this is the year.  We’ve never had nine candidates on the ballot before.  Your chance of making it through the NomCom are higher than in any previous year.  Unfortunately the more of you that run, the more of you that will lose in the election.  And hopefully that competition will mean more community involvement and better Board members for PASS. Is this the end of changes to the election process?  It isn’t.  Every year that I’ve been on the Board the election process has changed.  Some years there have been small changes and some years there have been large changes.  After this election we’ll look at how the process worked and decide what steps to take – just like we do every year.

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• The Faces in the Crowdsourcing

  - by Applications User Experience

  By Jeff Sauro, Principal Usability Engineer, Oracle Imagine having access to a global workforce of hundreds of thousands of people who can perform tasks or provide feedback on a design quickly and almost immediately. Distributing simple tasks not easily done by computers to the masses is called "crowdsourcing" and until recently was an interesting concept, but due to practical constraints wasn't used often. Enter Amazon.com. For five years, Amazon has hosted a service called Mechanical Turk, which provides an easy interface to the crowds. The service has almost half a million registered, global users performing a quarter of a million human intelligence tasks (HITs). HITs are submitted by individuals and companies in the U.S. and pay from $.01 for simple tasks (such as determining if a picture is offensive) to several dollars (for tasks like transcribing audio). What do we know about the people who toil away in this digital crowd? Can we rely on the work done in this anonymous marketplace? A rendering of the actual Mechanical Turk (from Wikipedia) Knowing who is behind Amazon's Mechanical Turk is fitting, considering the history of the actual Mechanical Turk. In the late 1800's, a mechanical chess-playing machine awed crowds as it beat master chess players in what was thought to be a mechanical miracle. It turned out that the creator, Wolfgang von Kempelen, had a small person (also a chess master) hiding inside the machine operating the arms to provide the illusion of automation. The field of human computer interaction (HCI) is quite familiar with gathering user input and incorporating it into all stages of the design process. It makes sense then that Mechanical Turk was a popular discussion topic at the recent Computer Human Interaction usability conference sponsored by the Association for Computing Machinery in Atlanta. It is already being used as a source for input on Web sites (for example, Feedbackarmy.com) and behavioral research studies. Two papers shed some light on the faces in this crowd. One paper tells us about the shifting demographics from mostly stay-at-home moms to young men in India. The second paper discusses the reliability and quality of work from the workers. Just who exactly would spend time doing tasks for pennies? In "Who are the crowdworkers?" University of California researchers Ross, Silberman, Zaldivar and Tomlinson conducted a survey of Mechanical Turk worker demographics and compared it to a similar survey done two years before. The initial survey reported workers consisting largely of young, well-educated women living in the U.S. with annual household incomes above $40,000. The more recent survey reveals a shift in demographics largely driven by an influx of workers from India. Indian workers went from 5% to over 30% of the crowd, and this block is largely male (two-thirds) with a higher average education than U.S. workers, and 64% report an annual income of less than $10,000 (keeping in mind $1 has a lot more purchasing power in India). This shifting demographic certainly has implications as language and culture can play critical roles in the outcome of HITs. Of course, the demographic data came from paying Turkers $.10 to fill out a survey, so there is some question about both a self-selection bias (characteristics which cause Turks to take this survey may be unrepresentative of the larger population), not to mention whether we can really trust the data we get from the crowd. Crowds can perform tasks or provide feedback on a design quickly and almost immediately for usability testing. (Photo attributed to victoriapeckham Flikr While having immediate access to a global workforce is nice, one major problem with Mechanical Turk is the incentive structure. Individuals and companies that deploy HITs want quality responses for a low price. Workers, on the other hand, want to complete the task and get paid as quickly as possible, so that they can get on to the next task. Since many HITs on Mechanical Turk are surveys, how valid and reliable are these results? How do we know whether workers are just rushing through the multiple-choice responses haphazardly answering? In "Are your participants gaming the system?" researchers at Carnegie Mellon (Downs, Holbrook, Sheng and Cranor) set up an experiment to find out what percentage of their workers were just in it for the money. The authors set up a 30-minute HIT (one of the more lengthy ones for Mechanical Turk) and offered a very high $4 to those who qualified and $.20 to those who did not. As part of the HIT, workers were asked to read an email and respond to two questions that determined whether workers were likely rushing through the HIT and not answering conscientiously. One question was simple and took little effort, while the second question required a bit more work to find the answer. Workers were led to believe other factors than these two questions were the qualifying aspect of the HIT. Of the 2000 participants, roughly 1200 (or 61%) answered both questions correctly. Eighty-eight percent answered the easy question correctly, and 64% answered the difficult question correctly. In other words, about 12% of the crowd were gaming the system, not paying enough attention to the question or making careless errors. Up to about 40% won't put in more than a modest effort to get paid for a HIT. Young men and those that considered themselves in the financial industry tended to be the most likely to try to game the system. There wasn't a breakdown by country, but given the demographic information from the first article, we could infer that many of these young men come from India, which makes language and other cultural differences a factor. These articles raise questions about the role of crowdsourcing as a means for getting quick user input at low cost. While compensating users for their time is nothing new, the incentive structure and anonymity of Mechanical Turk raises some interesting questions. How complex of a task can we ask of the crowd, and how much should these workers be paid? Can we rely on the information we get from these professional users, and if so, how can we best incorporate it into designing more usable products? Traditional usability testing will still play a central role in enterprise software. Crowdsourcing doesn't replace testing; instead, it makes certain parts of gathering user feedback easier. One can turn to the crowd for simple tasks that don't require specialized skills and get a lot of data fast. As more studies are conducted on Mechanical Turk, I suspect we will see crowdsourcing playing an increasing role in human computer interaction and enterprise computing. References: Downs, J. S., Holbrook, M. B., Sheng, S., and Cranor, L. F. 2010. Are your participants gaming the system?: screening mechanical turk workers. In Proceedings of the 28th international Conference on Human Factors in Computing Systems (Atlanta, Georgia, USA, April 10 - 15, 2010). CHI '10. ACM, New York, NY, 2399-2402. Link: http://doi.acm.org/10.1145/1753326.1753688 Ross, J., Irani, L., Silberman, M. S., Zaldivar, A., and Tomlinson, B. 2010. Who are the crowdworkers?: shifting demographics in mechanical turk. In Proceedings of the 28th of the international Conference Extended Abstracts on Human Factors in Computing Systems (Atlanta, Georgia, USA, April 10 - 15, 2010). CHI EA '10. ACM, New York, NY, 2863-2872. Link: http://doi.acm.org/10.1145/1753846.1753873

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• Agile Testing Days 2012 – Day 3 – Agile or agile?

  - by Chris George

  Another early start for my last Lean Coffee of the conference, and again it was not wasted. We had some really interesting discussions around how to determine what test automation is useful, if agile is not faster, why do it? and a rather existential discussion on whether unicorns exist! First keynote of the day was entitled “Fast Feedback Teams” by Ola Ellnestam. Again this relates nicely to the releasing faster talk on day 2, and something that we are looking at and some teams are actively trying. Introducing the notion of feedback, Ola describes a game he wrote for his eldest child. It was a simple game where every time he clicked a button, it displayed “You’ve Won!”. He then changed it to be a Win-Lose-Win-Lose pattern and watched the feedback from his son who then twigged the pattern and got his younger brother to play, alternating turns… genius! (must do that with my children). The idea behind this was that you need that feedback loop to learn and progress. If you are not getting the feedback you need to close that loop. An interesting point Ola made was to solve problems BEFORE writing software. It may be that you don’t have to write anything at all, perhaps it’s a communication/training issue? Perhaps the problem can be solved another way. Writing software, although it’s the business we are in, is expensive, and this should be taken into account. He again mentions frequent releases, and how they should be made as soon as stuff is ready to be released, don’t leave stuff on the shelf cause it’s not earning you anything, money or data. I totally agree with this and it’s something that we will be aiming for moving forwards. “Exceptions, Assumptions and Ambiguity: Finding the truth behind the story” by David Evans started off very promising by making references to ‘Grim up North’ referring to the north of England. Not sure it was appreciated by most of the audience, but it made me laugh! David explained how there are always risks associated with exceptions, giving the example of a one-way road near where he lives, with an exception sign giving rights to coaches to go the wrong way. Therefore you could merrily swing around the corner of the one way road straight into a coach! David showed the danger in making assumptions with lyrical quotes from Lola by The Kinks “I’m glad I’m a man, and so is Lola” and with a picture of a toilet flush that needed instructions to operate the full and half flush. With this particular flush, you pulled the handle all the way down to half flush, and half way down to full flush! hmmm, a bit of a crappy user experience methinks! Then through a clever use of a passage from the Jabberwocky, David then went onto show how mis-translation/ambiguity is the can completely distort the original meaning of something, and this is a real enemy of software development. This was all helping to demonstrate that the term Story is often heavily overloaded in the Agile world, and should really be stripped back to what it is really for, stating a business problem, and offering a technical solution. Therefore a story could be worded as “In order to {make some improvement}, we will { do something}”. The first ‘in order to’ statement is stakeholder neutral, and states the problem through requesting an improvement to the software/process etc. The second part of the story is the verb, the doing bit. So to achieve the ‘improvement’ which is not currently true, we will do something to make this true in the future. My PM is very interested in this, and he’s observed some of the problems of overloading stories so I’m hoping between us we can use some of David’s suggestions to help clarify our stories better. The second keynote of the day (and our last) proved to be the most entertaining and exhausting of the conference for me. “The ongoing evolution of testing in agile development” by Scott Barber. I’ve never had the pleasure of seeing Scott before… OMG I would love to have even half of the energy he has! What struck me during this presentation was Scott’s explanation of how testing has become the role/job that it is (largely) today, and how this has led to the need for ‘methodologies’ to make dev and test work! The argument that we should be trying to converge the roles again is a very valid one, and one that a couple of the teams at work are actively doing with great results. Making developers as responsible for quality as testers is something that has been lost over the years, but something that we are now striving to achieve. The idea that we (testers) should be testing experts/specialists, not testing ‘union members’, supports this idea so the entire team works on all aspects of a feature/product, with the ‘specialists’ taking the lead and advising/coaching the others. This leads to better propagation of information around the team, a greater holistic understanding of the project and it allows the team to continue functioning if some of it’s members are off sick, for example. Feeling somewhat drained from Scott’s keynote (but at the same time excited that alot of the points he raised supported actions we are taking at work), I headed into my last presentation for Agile Testing Days 2012 before having to make my way to Tegel to catch the flight home. “Thinking and working agile in an unbending world” with Pete Walen was a talk I was not going to miss! Having spoken to Pete several times during the past few days, I was looking forward to hearing what he was going to say, and I was not disappointed. Pete started off by trying to separate the definitions of ‘Agile’ as in the methodology, and ‘agile’ as in the adjective by pronouncing them the ‘english’ and ‘american’ ways. So Agile pronounced (Ajyle) and agile pronounced (ajul). There was much confusion around what the hell he was talking about, although I thought it was quite clear. Agile – Software development methodology agile – Marked by ready ability to move with quick easy grace; Having a quick resourceful and adaptable character. Anyway, that aside (although it provided a few laughs during the presentation), the point was that many teams that claim to be ‘Agile’ but are not, in fact, ‘agile’ by nature. Implementing ‘Agile’ methodologies that are so prescriptive actually goes against the very nature of Agile development where a team should anticipate, adapt and explore. Pete made a valid point that very few companies intentionally put up roadblocks to impede work, so if work is being blocked/delayed, why? This is where being agile as a team pays off because the team can inspect what’s going on, explore options and adapt their processes. It is through experimentation (and that means trying and failing as well as trying and succeeding) that a team will improve and grow leading to focussing on what really needs to be done to achieve X. So, that was it, the last talk of our conference. I was gutted that we had to miss the closing keynote from Matt Heusser, as Matt was another person I had spoken too a few times during the conference, but the flight would not wait, and just as well we left when we did because the traffic was a nightmare! My Takeaway Triple from Day 3: Release often and release small – don’t leave stuff on the shelf Keep the meaning of the word ‘agile’ in mind when working in ‘Agile Look at testing as more of a skill than a role  

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• SQL Sentry First Impressions

  - by AjarnMark

  After struggling to defend my SQL Servers from a political attack recently, I realized that I needed better tools to back me up, and SQL Sentry is the leading candidate. A couple of weeks ago, seemingly from out of nowhere, complaints from the business users started coming in that one of the core internal applications was running dramatically slower than normal, and fingers were being pointed at the SQL Server.  Unfortunately, we don’t have a production DBA whose entire job is to monitor and maintain our SQL Servers.  The responsibility falls to me to do the best I can, investing only a small portion of my time, because there are so many other responsibilities to take care of, and our industry is still deep in recession.  I inherited these SQL Servers and have made significant improvements in process and procedure, but I had not yet made the time to take real baseline measurements or keep a really close eye on the performance.  Like many DBAs, I wrote several of my own tools and used the “built-in tools” like Profiler, PerfMon, and sp_who2 (did I mention most of our instances are SQL Server 2000?).  These have all served me well for in-the-moment troubleshooting and maintenance, but they really fell down on the job when I was called upon to “prove” that SQL Server performance was acceptable and more importantly had not degraded recently (i.e. historical comparisons).  I really didn’t have anything from a historical comparison perspective, but I was able to show that current performance was acceptable, and deflect attention back onto other components (which in fact turned out to be the real culprit). That experience dramatically illustrated the need for better monitoring tools.  Coincidentally, I had been talking recently to my boss about the mini nightmare of monitoring several critical and interdependent overnight jobs that operate on separate instances of SQL Server.  Among other tools, I had been using Idera’s SQL Job Manager which is a free tool and did a nice job of showing me job schedules and histories in a nice calendar view.  This worked fairly well, and for the money (did I mention it was free?) it couldn’t be beat.  But it is based on the stored job history in MSDB, and there were other performance problems that we ran into when we started changing the settings for how much job history to retain, in order to be able to look back a month or more in the calendar view.  Another coincidence (if you believe in such things) was that when we had some of those performance challenges, I posted a couple of questions to the #sqlhelp hashtag on Twitter and Greg Gonzalez (@SQLSensei) suggested I check out SQL Sentry’s Event Manager.  At the time, I just thought he worked there, but later found out that he founded the company.  When I took a quick look at the features & benefits, the one that really jumped out at me is Chaining and Queueing which sounded like it would really help with our “interdependent jobs on different servers” issue. I know that is a lot of background story and coincidences, but hopefully you have stuck with me so far, and now we have arrived at the point where last week I downloaded and installed the 30-day trial of the SQL Sentry Power Suite, which is Event Manager plus Performance Advisor.  And I must say that I really like what I see so far.  Here are a few highlights: Great Support.  I had two issues getting the trial setup and monitoring a handful of our servers.  One of which was entirely my fault (missed a security setting in SQL 2008) and the other was mostly my fault (late change to some config settings that were apparently cached and did not get refreshed properly).  In both cases, the support staff at SQL Sentry were very responsive and rather quickly figured out what the cause and fix was for each of them.  This left me with a great impression of the company.  Kudos to them! Chaining and Queueing.  While I have not yet activated this feature, I am very excited about the possibilities.  We have jobs on three different instances of SQL Server that have to be run in a certain order, and each has to finish before the next can successfully begin, and I believe this feature will ensure just that.  It has been a real pain in the backside when one of those jobs runs just a little too long and does not finish before the job on another instance starts, thus triggering a chain reaction of either outright job failures, or worse, successful completion of completely invalid processing. Calendar View.  I really, really like the Event Manager calendar view where I can see all jobs and events across all instances and identify potential resource contention as well as windows of opportunity for maintenance activity.  Very well done, and based on Event Manager’s own database of accumulated historical information rather than querying the source instances every time. Performance Advisor Dashboard History View.  This view let’s me quickly select a date and time range and it displays graphs of key SQL Server and Windows metrics.  This is exactly the thing I needed to answer the “has performance changed recently” question at the beginning of this post. Reporting Services Subscription Jobs with Report Name.  This was a big and VERY pleasant surprise.  If you have ever looked at the list of SQL Server jobs that SQL Server Reporting Services creates when you make a Subscription, you will notice that they all have some sort of GUID as the name of the job.  This is really ugly, and really annoying because when you are just looking at the SQL Agent and Job Activity Monitor, if you see that Job X failed, you really do not have any indication in the name or the properties of the Job itself, as to what Report that was for.  But with SQL Sentry Event Manager you do.  The Jobs list in the Navigator pane in SQL Sentry, amazingly, displays the name of the Report that the Subscription Job is for.  And when you open it to see more details, it shows you the full Reporting Services path to that Report, so you can immediately track it down in the Report Manager in case you want to identify/notify the owner or edit the Subscription information.  I did not expect this at all, but I sure do like it.  HOORAY! That is just my first impressions from using the tools for a few days.  And I haven’t even gotten into how it showed me where I was completely mistaken about one aspect of my SQL Server disk configurations.  I’ll share that lesson in another blog entry.  But I have to say it again, the combination of Event Manager and Performance Advisor working together have really made me a fan.

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• 3D Ball Physics Theory: collision response on ground and against walls?

  - by David

  I'm really struggling to get a strong grasp on how I should be handling collision response in a game engine I'm building around a 3D ball physics concept. Think Monkey Ball as an example of the type of gameplay. I am currently using sphere-to-sphere broad phase, then AABB to OBB testing (the final test I am using right now is one that checks if one of the 8 OBB points crosses the planes of the object it is testing against). This seems to work pretty well, and I am getting back: Plane that object is colliding against (with a point on the plane, the plane's normal, and the exact point of intersection. I've tried what feels like dozens of different high-level strategies for handling these collisions, without any real success. I think my biggest problem is understanding how to handle collisions against walls in the x-y axes (left/right, front/back), which I want to have elasticity, and the ground (z-axis) where I want an elastic reaction if the ball drops down, but then for it to eventually normalize and be kept "on the ground" (not go into the ground, but also not continue bouncing). Without kluging something together, I'm positive there is a good way to handle this, my theories just aren't getting me all the way there. For physics modeling and movement, I am trying to use a Euler based setup with each object maintaining a position (and destination position prior to collision detection), a velocity (which is added onto the position to determine the destination position), and an acceleration (which I use to store any player input being put on the ball, as well as gravity in the z coord). Starting from when I detect a collision, what is a good way to approach the response to get the expected behavior in all cases? Thanks in advance to anyone taking the time to assist... I am grateful for any pointers, and happy to post any additional info or code if it is useful. UPDATE Based on Steve H's and eBusiness' responses below, I have adapted my collision response to what makes a lot more sense now. It was close to right before, but I didn't have all the right pieces together at the right time! I have one problem left to solve, and that is what is causing the floor collision to hit every frame. Here's the collision response code I have now for the ball, then I'll describe the last bit I'm still struggling to understand. // if we are moving in the direction of the plane (against the normal)... if (m_velocity.dot(intersection.plane.normal) <= 0.0f) { float dampeningForce = 1.8f; // eventually create this value based on mass and acceleration // Calculate the projection velocity PVRTVec3 actingVelocity = m_velocity.project(intersection.plane.normal); m_velocity -= actingVelocity * dampeningForce; } // Clamp z-velocity to zero if we are within a certain threshold // -- NOTE: this was an experimental idea I had to solve the "jitter" bug I'll describe below float diff = 0.2f - abs(m_velocity.z); if (diff > 0.0f && diff <= 0.2f) { m_velocity.z = 0.0f; } // Take this object to its new destination position based on... // -- our pre-collision position + vector to the collision point + our new velocity after collision * time // -- remaining after the collision to finish the movement m_destPosition = m_position + intersection.diff + (m_velocity * intersection.tRemaining * GAMESTATE->dt); The above snippet is run after a collision is detected on the ball (collider) with a collidee (floor in this case). With a dampening force of 1.8f, the ball's reflected "upward" velocity will eventually be overcome by gravity, so the ball will essentially be stuck on the floor. THIS is the problem I have now... the collision code is running every frame (since the ball's z-velocity is constantly pushing it a collision with the floor below it). The ball is not technically stuck, I can move it around still, but the movement is really goofy because the velocity and position keep getting affected adversely by the above snippet. I was experimenting with an idea to clamp the z-velocity to zero if it was "close to zero", but this didn't do what I think... probably because the very next frame the ball gets a new gravity acceleration applied to its velocity regardless (which I think is good, right?). Collisions with walls are as they used to be and work very well. It's just this last bit of "stickiness" to deal with. The camera is constantly jittering up and down by extremely small fractions too when the ball is "at rest". I'll keep playing with it... I like puzzles like this, especially when I think I'm close. Any final ideas on what I could be doing wrong here? UPDATE 2 Good news - I discovered I should be subtracting the intersection.diff from the m_position (position prior to collision). The intersection.diff is my calculation of the difference in the vector of position to destPosition from the intersection point to the position. In this case, adding it was causing my ball to always go "up" just a little bit, causing the jitter. By subtracting it, and moving that clamper for the velocity.z when close to zero to being above the dot product (and changing the test from <= 0 to < 0), I now have the following: // Clamp z-velocity to zero if we are within a certain threshold float diff = 0.2f - abs(m_velocity.z); if (diff > 0.0f && diff <= 0.2f) { m_velocity.z = 0.0f; } // if we are moving in the direction of the plane (against the normal)... float dotprod = m_velocity.dot(intersection.plane.normal); if (dotprod < 0.0f) { float dampeningForce = 1.8f; // eventually create this value based on mass and acceleration? // Calculate the projection velocity PVRTVec3 actingVelocity = m_velocity.project(intersection.plane.normal); m_velocity -= actingVelocity * dampeningForce; } // Take this object to its new destination position based on... // -- our pre-collision position + vector to the collision point + our new velocity after collision * time // -- remaining after the collision to finish the movement m_destPosition = m_position - intersection.diff + (m_velocity * intersection.tRemaining * GAMESTATE->dt); UpdateWorldMatrix(m_destWorldMatrix, m_destOBB, m_destPosition, false); This is MUCH better. No jitter, and the ball now "rests" at the floor, while still bouncing off the floor and walls. The ONLY thing left is that the ball is now virtually "stuck". He can move but at a much slower rate, likely because the else of my dot product test is only letting the ball move at a rate multiplied against the tRemaining... I think this is a better solution than I had previously, but still somehow not the right idea. BTW, I'm trying to journal my progress through this problem for anyone else with a similar situation - hopefully it will serve as some help, as many similar posts have for me over the years.

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• 5 Best Practices - Laying the Foundation for WebCenter Projects

  - by Kellsey Ruppel

  Today’s guest post comes from Oracle WebCenter expert John Brunswick. John specializes in enterprise portal and content management solutions and actively contributes to the enterprise software business community and has authored a series of articles about optimal business involvement in portal, business process management and SOA development, examining ways of helping organizations move away from monolithic application development. We’re happy to have John join us today! Maximizing success with Oracle WebCenter portal requires a strategic understanding of Oracle WebCenter capabilities.  The following best practices enable the creation of portal solutions with minimal resource overhead, while offering the greatest flexibility for progressive elaboration. They are inherently project agnostic, enabling a strong foundation for future growth and an expedient return on your investment in the platform.  If you are able to embrace even only a few of these practices, you will materially improve your deployment capability with WebCenter. 1. Segment Duties Around 3Cs - Content, Collaboration and Contextual Data "Agility" is one of the most common business benefits touted by modern web platforms.  It sounds good - who doesn't want to be Agile, right?  How exactly IT organizations go about supplying agility to their business counterparts often lacks definition - hamstrung by ambiguity. Ultimately, businesses want to benefit from reduced development time to deliver a solution to a particular constituent, which is augmented by as much self-service as possible to develop and manage the solution directly. All done in the absence of direct IT involvement. With Oracle WebCenter's depth in the areas of content management, pallet of native collaborative services, enterprise mashup capability and delegated administration, it is very possible to execute on this business vision at a technical level. To realize the benefits of the platform depth we can think of Oracle WebCenter's segmentation of duties along the lines of the 3 Cs - Content, Collaboration and Contextual Data.  All three of which can have their foundations developed by IT, then provisioned to the business on a per role basis. Content – Oracle WebCenter benefits from an extremely mature content repository.  Work flow, audit, notification, office integration and conversion capabilities for documents (HTML & PDF) make this a haven for business users to take control of content within external and internal portals, custom applications and web sites.  When deploying WebCenter portal take time to think of areas in which IT can provide the "harness" for content to reside, then allow the business to manage any content items within the site, using the content foundation to ensure compliance with business rules and process.  This frees IT to work on more mission critical challenges and allows the business to respond in short order to emerging market needs. Collaboration – Native collaborative services and WebCenter spaces are a perfect match for business users who are looking to enable document sharing, discussions and social networking.  The ability to deploy the services is granular and on the basis of roles scoped to given areas of the system - much like the first C “content”.  This enables business analysts to design the roles required and IT to provision with peace of mind that users leveraging the collaborative services are only able to do so in explicitly designated areas of a site. Bottom line - business will not need to wait for IT, but cannot go outside of the scope that has been defined based on their roles. Contextual Data – Collaborative capabilities are most powerful when included within the context of business data.  The ability to supply business users with decision shaping data that they can include in various parts of a portal or portals, just as they would with content items, is one of the most powerful aspects of Oracle WebCenter.  Imagine a discussion about new store selection for a retail chain that re-purposes existing information from business intelligence services about various potential locations and or custom backend systems - presenting it directly in the context of the discussion.  If there are some data sources that are preexisting in your enterprise take a look at how they can be made into discrete offerings within the portal, then scoped to given business user roles for inclusion within collaborative activities. 2. Think Generically, Execute Specifically Constructs.  Anyone who has spent much time around me knows that I am obsessed with this word.  Why? Because Constructs offer immense power - more than APIs, Web Services or other technical capability. Constructs offer organizations the ability to leverage a platform's native characteristics to offer substantial business functionality - without writing code.  This concept becomes more powerful with the additional understanding of the concepts from the platform that an organization learns over time.  Let's take a look at an example of where an Oracle WebCenter construct can substantially reduce the time to get a subscription-based site out the door and into the hands of the end consumer. Imagine a site that allows members to subscribe to specific disciplines to access information and application data around that various discipline.  A space is a collection of secured pages within Oracle WebCenter.  Spaces are not only secured, but also default content stored within it to be scoped automatically to that space. Taking this a step further, Oracle WebCenter’s Activity Stream surfaces events, discussions and other activities that are scoped to the given user on the basis of their space affiliations.  In order to have a portal that would allow users to "subscribe" to information around various disciplines - spaces could be used out of the box to achieve this capability and without using any APIs or low level technical work to achieve this. 3. Make Governance Work for You Imagine driving down the street without the painted lines on the road.  The rules of the road are so ingrained in our minds, we often do not think about the process, but seemingly mundane lane markers are critical enablers. Lane markers allow us to travel at speeds that would be impossible if not for the agreed upon direction of flow. Additionally and more importantly, it allows people to act autonomously - going where they please at any given time. The return on the investment for mobility is high enough for people to buy into globally agreed up governance processes. In Oracle WebCenter we can use similar enablers to lane markers.  Our goal should be to enable the flow of information and provide end users with the ability to arrive at business solutions as needed, not on the basis of cumbersome processes that cannot meet the business needs in a timely fashion. How do we do this? Just as with "Segmentation of Duties" Oracle WebCenter technologies offer the opportunity to compartmentalize various business initiatives from each other within the system due to constructs and security that are available to use within the platform. For instance, when a WebCenter space is created, any content added within that space by default will be secured to that particular space and inherits meta data that is associated with a folder created for the space. Oracle WebCenter content uses meta data to support a broad range of rich ECM functionality and can automatically impart retention, workflow and other policies automatically on the basis of what has been defaulted for that space. Depending on your business needs, this paradigm will also extend to sub sections of a space, offering some interesting possibilities to enable automated management around content. An example may be press releases within a particular area of an extranet that require a five year retention period and need to the reviewed by marketing and legal before release.  The underlying content system will transparently take care of this process on the basis of the above rules, enabling peace of mind over unstructured data - which could otherwise become overwhelming. 4. Make Your First Project Your Second Imagine if Michael Phelps was competing in a swimming championship, but told right before his race that he had to use a brand new stroke.  There is no doubt that Michael is an outstanding swimmer, but chances are that he would like to have some time to get acquainted with the new stroke. New technologies should not be treated any differently.  Before jumping into the deep end it helps to take time to get to know the new approach - even though you may have been swimming thousands of times before. To quickly get a handle on Oracle WebCenter capabilities it can be helpful to deploy a sandbox for the team to use to share project documents, discussions and announcements in an effort to help the actual deployment get under way, while increasing everyone’s knowledge of the platform and its functionality that may be helpful down the road. Oracle Technology Network has made a pre-configured virtual machine available for download that can be a great starting point for this exercise. 5. Get to Know the Community If you are reading this blog post you have most certainly faced a software decision or challenge that was solved on the basis of a small piece of missing critical information - which took substantial research to discover.  Chances were also good that somewhere, someone had already come across this information and would have been excited to share it. There is no denying the power of passionate, connected users, sharing key tips around technology.  The Oracle WebCenter brand has a rich heritage that includes industry-leading technology and practitioners.  With the new Oracle WebCenter brand, opportunities to connect with these experts has become easier. Oracle WebCenter Blog Oracle Social Enterprise LinkedIn WebCenter Group Oracle WebCenter Twitter Oracle WebCenter Facebook Oracle User Groups Additionally, there are various Oracle WebCenter related blogs by an excellent grouping of services partners.

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• Communities - The importance of exchange and discussion

  Communication with your environment is an essential part of everyone's life. And it doesn't matter whether you are actually living in a rural area in the middle of nowhere, within the pulsating heart of a big city, or in my case on a wonderful island in the Indian Ocean. The ability to exchange your thoughts, your experience and your worries with another person helps you to get different points of view and new ideas on how to resolve an issue you might be confronted with. Benefits of community work What happens to be common sense in your daily life, also applies to your work environment. Working in IT, or ICT as it is called in Mauritius, requires a lot of reading and learning. Not only during your lectures at the university but with your colleagues in a project assignment and hopefully with 'unknown' pals in the universe of online communities. At least I can say that I learned quite a lot from other developers code, their responses in various forums, their numerous blog articles, and while attending local user group meetings. When I started to work as a professional software developer (or engineer some may say) years ago I immediately checked the existence of communities on the programming language, the database technology and other vital information on software development in general. Luckily, it wasn't too difficult to find. My employer had a subscription of the monthly magazines and newsletters of a national organisation which also run the biggest forum in that area. Getting in touch with other developers and reading their common problems but also solutions was a huge benefit to my growth. Image courtesy of Michael Kappel (CC BY-NC 2.0) Active participation and regular contribution to this community gave me some nice advantages, too. Within three years I was listed as a conference speaker at the annual developer's conference and provided several sessions on different topics during consecutive years. Back in 2004, I took over the responsibility and management of the monthly meetings of a regional user group, and organised it for more than two years. Furthermore, I was invited to the newly-founded community program of Microsoft Germany (Community Leader/Insider Program - CLIP). My website on Active FoxPro Pages was nominated in the second batch of online communities. Due to my community work and providing advice to others, I had the honour to be awarded as Microsoft Most Valuable Professional (MVP) - Visual Developer for Visual FoxPro in the years 2006 and 2007. It was a great experience to meet with other like-minded people and I'm really grateful for that. Just in case, more details are listed in my Curriculum Vitae. But this all changed when I moved to Mauritius... Cyber island Mauritius? During the first months in Mauritius I was way too busy to think about community activities at all. First of all, there was the new company that had to be set up, the new staff had to be trained and of course the communication work-flows and so on with the project managers back in Germany had to be sorted out, too. Second, I had to get a grip of my private matters like getting the basics for my new household or exploring the neighbourhood, and last but not least I needed a break from the hectic and intensive work prior to my departure. As soon as the sea literally calmed down, I started to have conversations with my colleagues about communities and user groups. Sadly, it turned out that there were none, or at least no one was aware of any at that time. Oh oh, what did I do? Anyway, having this kind of background and very positive experience with off-line and on-line activities I decided for myself that some day I'm going to found a community in Mauritius for all kind of IT/ICT-related fields. The main focus might be on software development but not on a certain technology or methodology. It was clear to me that it should be an open infrastructure and anyone is welcome to join, to experience, to share and to contribute if they would like to. That was the idea at that time... Ok, fast-forward to recent events. At the end of October 2012 I was invited to an event called Open Days organised by Microsoft Indian Ocean Islands together with other local partners and resellers. There I got in touch with local Technical Evangelist Arnaud Meslier and we had a good conversation on communities during the breaks. Eventually, I left a good impression on him, as we are having chats on Facebook or Skype irregularly. Well, seeing that my personal and professional surroundings have been settled and running smooth, having that great exchange and contact with Microsoft IOI (again), and being really eager to re-animate my intentions from 2007, I recently founded a new community: Mauritius Software Craftsmanship Community - #MSCC It took me a while to settle down with the name but it was obvious that the community should not be attached to one single technology, like ie. .NET user group, Oracle developers, or Joomla friends (these are fictitious names). There are several other reasons why I came up with 'Craftsmanship' as the core topic of this community. The expression of 'engineering' didn't feel right with the fields covered. Software development in all kind of facets is a craft, and therefore demands a lot of practice but also guidance from more experienced developers. It also includes the process of designing, modelling and drafting the ideas. Has to deal with various types of tests and test methodologies, and of course should be focused on flexible and agile ways of acting. In order to meet and to excel a customer's request for a solution. Next, I was looking for an easy way to handle the organisation of events and meeting appointments. Using all kind of social media platforms like Google+, LinkedIn, Facebook, Xing, etc. I was never really confident about their features of event handling. More by chance I stumbled upon Meetup.com and in combination with the other entities (G+ Communities, FB Pages or in Groups) I am looking forward to advertise and manage all future activities here: Mauritius Software Craftsmanship Community This is a community for those who care and are proud of what they do. For those developers, regardless how experienced they are, who want to improve and master their craft. This is a community for those who believe that being average is just not good enough. I know, there are not many 'craftsmen' yet but it's a start... Let's see how it looks like by the end of the year. There are free smartphone apps for Android and iOS from Meetup.com that allow you to keep track of meetings and to stay informed on latest updates. And last but not least, there will be a Trello workspace to collect and share ideas and provide downloads of slides, etc. Sharing is caring! As mentioned, the #MSCC is present in various social media networks in order to cover as many people as possible here in Mauritius. Following is an overview of the current networks: Twitter - Latest updates and quickies Google+ - Community channel Facebook - Community Page LinkedIn - Community Group Trello - Collaboration workspace to share and develop ideas Hopefully, this covers the majority of computer-related people in Mauritius. Please spread the word about the #MSCC between your colleagues, your friends and other interested 'geeks'. Your future looks bright Running and participating in a user group or any kind of community usually provides quite a number of advantages for anyone. On the one side it is very joyful for me to organise appointments and get in touch with people that might be interested to present a little demo of their projects or their recent problems they had to tackle down, and on the other side there are lots of companies that have various support programs or sponsorships especially tailored for user groups. At the moment, I already have a couple of gimmicks that I would like to hand out in small contests or raffles during one of the upcoming meetings, and as said, companies provide all kind of goodies, books free of charge, or sometimes even licenses for communities. Meeting other software developers or IT guys also opens up your point of view on the local market and there might be interesting projects or job offers available, too. A community like the Mauritius Software Craftsmanship Community is great for freelancers, self-employed, students and of course employees. Meetings will be organised on a regular basis, and I'm open to all kind of suggestions from you. Please leave a comment here in blog or join the conversations in the above mentioned social networks. Let's get this community up and running, my fellow Mauritians!

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• Christmas in the Clouds

  - by andrewbrust

  I have been spending the last 2 weeks immersing myself in a number of Windows Azure and SQL Azure technologies.  And in setting up a new business (I’ll speak more about that in the future), I have also become a customer of Microsoft’s BPOS (Business Productivity Online Services).  In short, it has been a fortnight of Microsoft cloud computing. On the Azure side, I’ve looked, of course, at Web Roles and Worker Roles.  But I’ve also looked at Azure Storage’s REST API (including coding to it directly), I’ve looked at Azure Drive and the new VM Role; I’ve looked quite a bit at SQL Azure (including the project “Houston” Silverlight UI) and I’ve looked at SQL Azure labs’ OData service too. I’ve also looked at DataMarket and its integration with both PowerPivot and native Excel.  Then there’s AppFabric Caching, SQL Azure Reporting (what I could learn of it) and the Visual Studio tooling for Azure, including the storage of certificate-based credentials.  And to round it out with some user stuff, on the BPOS side, I’ve been working with Exchange Online, SharePoint Online and LiveMeeting. I have to say I like a lot of what I’ve been seeing.  Azure’s not perfect, and BPOS certainly isn’t either.  But there’s good stuff in all these products, and there’s a lot of value. Azure Goes Deep Most people know that Web and Worker roles put the platform in charge of spinning virtual machines up and down, and keeping them up to date. But you can go way beyond that now.  The still-in-beta VM Role gives you the power to craft the machine (much as does Amazon’s EC2), though it takes away the platform’s self-managing attributes.  It still spins instances up and down, making drive storage non-durable, but Azure Drive gives you the ability to store VHD files as blobs and mount them as virtual hard drives that are readable and writeable.  Whether with Azure Storage or SQL Azure, Azure does data.  And OData is everywhere.  Azure Table Storage supports an OData Interface.  So does SQL Azure and so does DataMarket (the former project “Dallas”).  That means that Azure data repositories aren’t just straightforward to provision and configure…they’re also easy to program against, from just about any programming environment, in a RESTful manner.  And for more .NET-centric implementations, Azure AppFabric caching takes the technology formerly known as “Velocity” and throws it up into the cloud, speeding data access even more. Snapping in Place Once you get the hang of it, this stuff just starts to work in a way that becomes natural to understand.  I wasn’t expecting that, and I was really happy to discover it. In retrospect, I am not surprised, because I think the various Azure teams are the center of gravity for Redmond’s innovation right now.  The products belie this and so do my observations of the product teams’ motivation and high morale.  It is really good to see this; Microsoft needs to lead somewhere, and they need to be seen as the underdog while doing so.  With Azure, both requirements are in place.   BPOS: Bad Acronym, Easy Setup BPOS is about products you already know; Exchange, SharePoint, Live Meeting and Office Communications Server.  As such, it’s hard not to be underwhelmed by BPOS.  Until you realize how easy it makes it to get all that stuff set up.  I would say that from sign-up to productive use took me about 45 minutes…and that included the time necessary to wrestle with my DNS provider, set up Outlook and my SmartPhone up to talk to the Exchange account, create my SharePoint site collection, and configure the Outlook Conferencing add-in to talk to the provisioned Live Meeting account. Never before did I think setting up my own Exchange mail could come anywhere close to the simplicity of setting up an SMTP/POP account, and yet BPOS actually made it faster.   What I want from my Azure Christmas Next Year Not everything about Microsoft’s cloud is good.  I close this post with a list of things I’d like to see addressed: BPOS offerings are still based on the 2007 Wave of Microsoft server technologies.  We need to get to 2010, and fast.  Arguably, the 2010 products should have been released to the off-premises channel before the on-premise sone.  Office 365 can’t come fast enough. Azure’s Internet tooling and domain naming, is scattered and confusing.  Deployed ASP.NET applications go to cloudapp.net; SQL Azure and Azure storage work off windows.net.  The Azure portal and Project Houston are at azure.com.  Then there’s appfabriclabs.com and sqlazurelabs.com.  There is a new Silverlight portal that replaces most, but not all of the HTML ones.  And Project Houston is Silvelright-based too, though separate from the Silverlight portal tooling. Microsoft is the king off tooling.  They should not make me keep an entire OneNote notebook full of portal links, account names, access keys, assemblies and namespaces and do so much CTRL-C/CTRL-V work.  I’d like to see more project templates, have them automatically reference the appropriate assemblies, generate the right using/Imports statements and prime my config files with the right markup.  Then I want a UI that lets me log in with my Live ID and pick the appropriate project, database, namespace and key string to get set up fast. Beta programs, if they’re open, should onboard me quickly.  I know the process is difficult and everyone’s going as fast as they can.  But I don’t know why it’s so difficult or why it takes so long.  Getting developers up to speed on new features quickly helps popularize the platform.  Make this a priority. Make Azure accessible from the simplicity platforms, i.e. ASP.NET Web Pages (Razor) and LightSwitch.  Support .NET 4 now.  Make WebMatrix, IIS Express and SQL Compact work with the Azure development fabric. Have HTML helpers make Azure programming easier.  Have LightSwitch work with SQL Azure and not require SQL Express.  LightSwitch has some promising Azure integration now.  But we need more.  WebMatrix has none and that’s just silly, now that the Extra Small Instance is being introduced. The Windows Azure Platform Training Kit is great.  But I want Microsoft to make it even better and I want them to evangelize it much more aggressively.  There’s a lot of good material on Azure development out there, but it’s scattered in the same way that the platform is.   The Training Kit ties a lot of disparate stuff together nicely.  Make it known. Should Old Acquaintance Be Forgot All in all, diving deep into Azure was a good way to end the year.  Diving deeper into Azure should a great way to spend next year, not just for me, but for Microsoft too.

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• Superclass Sensitive Actions

  - by Geertjan

  I've created a small piece of functionality that enables you to create actions for Java classes in the IDE. When the user right-clicks on a Java class, they will see one or more actions depending on the superclass of the selected class. To explain this visually, here I have "BlaTopComponent.java". I right-click on its node in the Projects window and I see "This is a TopComponent": Indeed, when you look at the source code of "BlaTopComponent.java", you'll see that it implements the TopComponent class. Next, in the screenshot below, you see that I have right-click a different class. In this case, there's an action available because the selected class implements the ActionListener class. Then, take a look at this one. Here both TopComponent and ActionListener are superclasses of the current class, hence both the actions are available to be invoked: Finally, here's a class that subclasses neither TopComponent nor ActionListener, hence neither of the actions that I created for doing something that relates to TopComponents or ActionListeners is available, since those actions are irrelevant in this context: How does this work? Well, it's a combination of my blog entries "Generic Node Popup Registration Solution" and "Showing an Action on a TopComponent Node". The cool part is that the definition of the two actions that you see above is remarkably trivial: import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JOptionPane; import org.openide.loaders.DataObject; import org.openide.util.Utilities; public class TopComponentSensitiveAction implements ActionListener { private final DataObject context; public TopComponentSensitiveAction() { context = Utilities.actionsGlobalContext().lookup(DataObject.class); } @Override public void actionPerformed(ActionEvent ev) { //Do something with the context: JOptionPane.showMessageDialog(null, "TopComponent: " + context.getNodeDelegate().getDisplayName()); } } The above is the action that will be available if you right-click a Java class that extends TopComponent. This, in turn, is the action that will be available if you right-click a Java class that implements ActionListener: import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JOptionPane; import org.openide.loaders.DataObject; import org.openide.util.Utilities; public class ActionListenerSensitiveAction implements ActionListener { private final DataObject context; public ActionListenerSensitiveAction() { context = Utilities.actionsGlobalContext().lookup(DataObject.class); } @Override public void actionPerformed(ActionEvent ev) { //Do something with the context: JOptionPane.showMessageDialog(null, "ActionListener: " + context.getNodeDelegate().getDisplayName()); } } Indeed, the classes, at this stage are the same. But, depending on what I want to do with TopComponents or ActionListeners, I now have a starting point, which includes access to the DataObject, from where I can get down into the source code, as shown here. This is how the two ActionListeners that you see defined above are registered in the layer, which could ultimately be done via annotations on the ActionListeners, of course: <folder name="Actions"> <folder name="Tools"> <file name="org-netbeans-sbas-impl-TopComponentSensitiveAction.instance"> <attr stringvalue="This is a TopComponent" name="displayName"/> <attr name="instanceCreate" methodvalue="org.netbeans.sbas.SuperclassSensitiveAction.create"/> <attr name="type" stringvalue="org.openide.windows.TopComponent"/> <attr name="delegate" newvalue="org.netbeans.sbas.impl.TopComponentSensitiveAction"/> </file> <file name="org-netbeans-sbas-impl-ActionListenerSensitiveAction.instance"> <attr stringvalue="This is an ActionListener" name="displayName"/> <attr name="instanceCreate" methodvalue="org.netbeans.sbas.SuperclassSensitiveAction.create"/> <attr name="type" stringvalue="java.awt.event.ActionListener"/> <attr name="delegate" newvalue="org.netbeans.sbas.impl.ActionListenerSensitiveAction"/> </file> </folder> </folder> <folder name="Loaders"> <folder name="text"> <folder name="x-java"> <folder name="Actions"> <file name="org-netbeans-sbas-impl-TopComponentSensitiveAction.shadow"> <attr name="originalFile" stringvalue="Actions/Tools/org-netbeans-sbas-impl-TopComponentSensitiveAction.instance"/> <attr intvalue="150" name="position"/> </file> <file name="org-netbeans-sbas-impl-ActionListenerSensitiveAction.shadow"> <attr name="originalFile" stringvalue="Actions/Tools/org-netbeans-sbas-impl-ActionListenerSensitiveAction.instance"/> <attr intvalue="160" name="position"/> </file> </folder> </folder> </folder> </folder> The most important parts of the layer registration are the lines that are highlighted above. Those lines connect the layer to the generic action that delegates back to the action listeners defined above, as follows: public final class SuperclassSensitiveAction extends AbstractAction implements ContextAwareAction { private final Map map; //This method is called from the layer, via "instanceCreate", //magically receiving a map, which contains all the attributes //that are defined in the layer for the file: static SuperclassSensitiveAction create(Map map) { return new SuperclassSensitiveAction(Utilities.actionsGlobalContext(), map); } public SuperclassSensitiveAction(Lookup context, Map m) { super(m.get("displayName").toString()); this.map = m; String superclass = m.get("type").toString(); //Enable the menu item only if //we're dealing with a class of type superclass: JavaSource javaSource = JavaSource.forFileObject( context.lookup(DataObject.class).getPrimaryFile()); try { javaSource.runUserActionTask(new ScanTask(this, superclass), true); } catch (IOException ex) { Exceptions.printStackTrace(ex); } //Hide the menu item if it isn't enabled: putValue(DynamicMenuContent.HIDE_WHEN_DISABLED, true); } @Override public void actionPerformed(ActionEvent ev) { ActionListener delegatedAction = (ActionListener)map.get("delegate"); delegatedAction.actionPerformed(ev); } @Override public Action createContextAwareInstance(Lookup actionContext) { return new SuperclassSensitiveAction(actionContext, map); } private class ScanTask implements Task<CompilationController> { private SuperclassSensitiveAction action = null; private String superclass; private ScanTask(SuperclassSensitiveAction action, String superclass) { this.action = action; this.superclass = superclass; } @Override public void run(final CompilationController info) throws Exception { info.toPhase(Phase.ELEMENTS_RESOLVED); new EnableIfGivenSuperclassMatches(info, action, superclass).scan( info.getCompilationUnit(), null); } } private static class EnableIfGivenSuperclassMatches extends TreePathScanner<Void, Void> { private CompilationInfo info; private final AbstractAction action; private final String superclassName; public EnableIfGivenSuperclassMatches(CompilationInfo info, AbstractAction action, String superclassName) { this.info = info; this.action = action; this.superclassName = superclassName; } @Override public Void visitClass(ClassTree t, Void v) { Element el = info.getTrees().getElement(getCurrentPath()); if (el != null) { TypeElement te = (TypeElement) el; List<? extends TypeMirror> interfaces = te.getInterfaces(); if (te.getSuperclass().toString().equals(superclassName)) { action.setEnabled(true); } else { action.setEnabled(false); } for (TypeMirror typeMirror : interfaces) { if (typeMirror.toString().equals(superclassName)){ action.setEnabled(true); } } } return null; } } } This is a pretty cool solution and, as you can see, very generic. Create a new ActionListener, register it in the layer so that it maps to the generic class above, and make sure to set the type attribute, which defines the superclass to which the action should be sensitive.

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• Learnings from trying to write better software: Loud errors from the very start

  - by theo.spears

  Microsoft made a very small number of backwards incompatible changes between .NET 1.1 and 2.0, because they wanted to make it as easy and safe as possible to port applications to the new runtime. (Here’s a list.) However, one thing they did change was what happens when a background thread fails with an unhanded exception - in .NET 1.1 nothing happened, the thread terminated, and the application continued oblivious. Try the same trick in .NET 2.0 and the entire application, including all threads, will rudely terminate. There are three reasons for this. Firstly if a background thread has crashed, it may have left the entire application in an inconsistent state, in a way that will affect other threads. It’s better to terminate the entire application than continue and have the application perform actions based on a broken state, for example take customer orders, or write corrupt files to disk.  Secondly, during software development, it is far better for errors to be loud and obtrusive. Even if you have unit tests and integration tests (and you should), a key part of ensuring software works properly is to actually try using it, both through systematic testing and through the casual use all software gets by its developers during use. Subtle errors are easy to miss if you are not actually doing real work using the application, loud errors are obvious. Thirdly, and most importantly, even if catching and swallowing exceptions indiscriminately doesn't cause any problems in your application, the presence of unexpected exceptions shows you do not fully understand the behavior of your code. The currently released version of your application may be absolutely correct. However, because your mental model of the behavior is wrong, any future change you make to the program could and probably will introduce critical errors.  This applies to more than just exceptions causing threads to exit, any unexpected state should make the application blow up in an un-ignorable way. The worst thing you can do is silently swallow errors and continue. And let's be clear, writing to a log file does not count as blowing up in an un-ignorable way.  This is all simple as long as the call stack only contains your code, but when your functions start to be called by third party or .NET framework code, it's surprisingly easy for exceptions to start vanishing. Let's look at two examples.   1. Windows forms drag drop events  Usually if you throw an exception from a winforms event handler it will bring up the "application has crashed" dialog with abort and continue options. This is a good default behavior - the error is big and loud, but it is possible for the user to ignore the error and hopefully save their data, if somehow this bug makes it past testing. However drag and drop are different - throw an exception from one of these and it will just be silently swallowed with no explanation.  By the way, it's not just drag and drop events. Timer events do it too.  You can research how exceptions are treated in different handlers and code appropriately, but the safest and most user friendly approach is to always catch exceptions in your event handlers and show your own error message. I'll talk about one good approach to handling these exceptions at the end of this post.   2. SSMS integration for SQL Tab Magic  A while back wrote an SSMS add-in called SQL Tab Magic (learn more about the process here). It works by listening to certain SSMS events and remembering what documents are opened and closed. I deployed it internally and it was used for a few months by a number of people without problems, so I was reasonably confident in its quality. Before releasing I made a few cleanups, including introducing error reporting. Bam. A few days later I was looking at over 1,000 error reports in my inbox. In turns out I wasn't handling table designers properly. The exceptions were there, but again SSMS was helpfully swallowing them all for me, so I was blissfully unaware. Had I made my errors loud from the start, I would have noticed these issues long before and fixed them.   Handling exceptions  Now you are systematically catching exceptions throughout your application, you need to do something with them. I've tried 3 options: log them, alert the user, and automatically send them home.  There are a few good options for logging in .NET. The most widespread is Apache log4net, which provides a very capable and configurable logging framework. There is also NLog which has a compatible interface, with a greater emphasis on fluent rather than XML configuration.  Alerting the user serves two purposes. Firstly it means they understand their action has failed to they don't just assume it worked (Silent file copy failure is a problem if you then delete the originals) or that they should keep waiting for a background task to complete. Secondly, it means the users can report the bug to your support team, and then you can fix it. This means the message you show the user should contain the information you need as a developer to identify and fix it. And the user will probably just send you a screenshot of the dialog, so it shouldn't be hidden by scroll bars.  This leads us to the third option, automatically sending error reports home. By automatic I mean with minimal effort on the part of the user, rather than doing it silently behind their backs. The advantage of this is you can send back far more detailed and precise information than you can expect a user to include in an email, and by making it easier to report errors, you make it more likely users will do so.  We do this using a great tool called SmartAssembly (full disclosure: this is a product made by Red Gate). It captures complete stack traces including the values of all local variables and then allows the user to send all this information back with a single click. We also capture log files to help understand what lead up to the error. We then use the free SmartAssembly Sync for Jira to dedupe these reports and raise them as bugs in our bug tracking system.  The combined effect of loud errors during development and then automatic error reporting once software is deployed allows us to find and fix more bugs, correct misunderstandings on how our software works, and overall is a key piece in delivering higher quality software. However it is no substitute for having motivated cunning testers in the building - and we're looking to hire more of those too.   If you found this post interesting you should follow me on twitter.  

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• BRE (Business Rules Engine) Data Services is out...!!!

  - by Vishal

  A few months ago we at Tellago had open sourced the BizTalk Data Services. We were meanwhile working on other artifacts which comes along with BizTalk Server like the “Business Rules Engine”.  We are happy to announce the first version of BRE Data Services. BRE Data Services is a same concept which we covered through BTS Data Services, providing a RESTFul OData – based API to interact with the Business Rules Engine via HTTP using ATOM Publishing Protocol or JSON as the encoding mechanism.   In the first version release, we mainly focused on the browsing, querying and searching BRE artifacts via a RESTFul interface. Also along with that we provide the functionality to execute Business Rules by inserting the Facts for policies via the IUpdatable implementation of WCF Data Services.   The BRE Data Services API provides a lightweight interface for managing Business Rules Engine artifacts such as Policies, Rules, Vocabularies, Conditions, Actions, Facts etc. The following are some examples which details some of the available features in the current version of the API.   Basic Querying: Querying BRE Policies http://localhost/BREDataServices/BREMananagementService.svc/Policies Querying BRE Rules http://localhost/BREDataServices/BREMananagementService.svc/Rules Querying BRE Vocabularies http://localhost/BREDataServices/BREMananagementService.svc/Vocabularies   Navigation: The BRE Data Services API also leverages WCF Data Services to enable navigation across related different BRE objects. Querying a specific Policy http://localhost/BREDataServices/BREMananagementService.svc/Policies(‘PolicyName’) Querying a specific Rule http://localhost/BREDataServices/BREMananagementService.svc/Rules(‘RuleName’) Querying all Rules under a Policy http://localhost/BREDataServices/BREMananagementService.svc/Policies('PolicyName')/Rules Querying all Facts under a Policy http://localhost/BREDataServices/BREMananagementService.svc/Policies('PolicyName')/Facts Querying all Actions for a specific Rule http://localhost/BREDataServices/BREMananagementService.svc/Rules('RuleName')/Actions Querying all Conditions for a specific Rule http://localhost/BREDataServices/BREMananagementService.svc/Rules('RuleName')/Actions Querying a specific Vocabulary: http://localhost/BREDataServices/BREMananagementService.svc/Vocabularies('VocabName')   Implementation: With the BRE Data Services, we also provide the functionality of executing a particular policy via HTTP. There are couple of ways you can do that though the API.   Ø First is though Service Operations feature of WCF Data Services in which you can execute the Facts by passing them in the URL itself. This is a very simple implementations of the executing the policies due to the limitations & restrictions (only primitive types of input parameters which can be passed) currently of the Service Operations of the WCF Data Services. Below is a code sample.                Below is a traced Request/Response message.                                 Ø Second is through the IUpdatable Interface of WCF Data Services. In this method, you can first query the rule which you want to execute and then inserts Facts for that particular Rules and finally when you perform the SaveChanges() call for the IUpdatable Interface API, it executes the policy with the facts which you inserted at runtime. Below is a sample of client side code. Due to the limitations of current version of WCF Data Services where there is no way you can return back the updates happening on the service side back to the client via the SaveChanges() method. Here we are executing the rule passing a serialized XML as Facts and there is no changes made to any data where we can query back to fetch the changes. This is overcome though the first way to executing the policies which is by executing it as a Service Operation call.     This actually generates a AtomPub message shown as below:   POST /Tellago.BRE.REST.ServiceHost/BREMananagementService.svc/$batch HTTP/1.1 User-Agent: Microsoft ADO.NET Data Services DataServiceVersion: 1.0;NetFx MaxDataServiceVersion: 2.0;NetFx Accept: application/atom+xml,application/xml Accept-Charset: UTF-8 Content-Type: multipart/mixed; boundary=batch_6b9a5ced-5ecb-4585-940a-9d5e704c28c7 Host: localhost:8080 Content-Length: 1481 Expect: 100-continue   --batch_6b9a5ced-5ecb-4585-940a-9d5e704c28c7 Content-Type: multipart/mixed; boundary=changeset_184a8c59-a714-4ba9-bb3d-889a88fe24bf   --changeset_184a8c59-a714-4ba9-bb3d-889a88fe24bf Content-Type: application/http Content-Transfer-Encoding: binary   MERGE http://localhost:8080/Tellago.BRE.REST.ServiceHost/BREMananagementService.svc/Facts('TestPolicy') HTTP/1.1 Content-ID: 4 Content-Type: application/atom+xml;type=entry Content-Length: 927   <?xml version="1.0" encoding="utf-8" standalone="yes"?> <entry xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" font-size: x-small"http://www.w3.org/2005/Atom">   <category scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" term="Tellago.BRE.REST.Resources.Fact" />   <title />   <author>     <name />   </author>   <updated>2011-01-31T20:09:15.0023982Z</updated>   <id>http://localhost:8080/Tellago.BRE.REST.ServiceHost/BREMananagementService.svc/Facts('TestPolicy')</id>   <content type="application/xml">     <m:properties>       <d:FactInstance>&lt;ns0:LoanStatus xmlns:ns0="http://tellago.com"&gt;&lt;Age&gt;10&lt;/Age&gt;&lt;Status&gt;true&lt;/Status&gt;&lt;/ns0:LoanStatus&gt;</d:FactInstance>       <d:FactType>TestSchema</d:FactType>       <d:ID>TestPolicy</d:ID>     </m:properties>   </content> </entry> --changeset_184a8c59-a714-4ba9-bb3d-889a88fe24bf-- --batch_6b9a5ced-5ecb-4585-940a-9d5e704c28c7—     Installation: The installation of the BRE Data Services is pretty straight forward. ·         Create a new IIS website say BREDataServices. ·         Download the SourceCode from TellagoCodeplex and copy the content from Tellago.BRE.REST.ServiceHost to the physical location of the above created website.     ·         The appPool account running the website should have admin access to the BizTalkRuleEngineDb database. ·         TheRight click the BREManagementService.svc in the IIS ContentView for the website and wala..     Conclusion: The BRE Data Services API is an experiment intended to bring the capabilities of RESTful/OData based services to the Traditional BTS/BRE Solutions. The future releases will target on technologies like BAM, ESB Toolkit. This version has been tested with various version of BizTalk Server and we have uploaded the source code to our Tellago's DevLabs workspace at Codeplex. I hope you guys enjoy this release. Keep an eye on our new releases @ Tellago Codeplex. We are working on various other Biztalk Artifacts like BAM, ESB Toolkit.     Till than happy BizzRuling…!!!     Thanks,   Vishal Mody

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• External File Upload Optimizations for Windows Azure

  - by rgillen

  [Cross posted from here: http://rob.gillenfamily.net/post/External-File-Upload-Optimizations-for-Windows-Azure.aspx] I’m wrapping up a bit of the work we’ve been doing on data movement optimizations for cloud computing and the latest set of data yielded some interesting points I thought I’d share. The work done here is not really rocket science but may, in some ways, be slightly counter-intuitive and therefore seemed worthy of posting. Summary: for those who don’t like to read detailed posts or don’t have time, the synopsis is that if you are uploading data to Azure, block your data (even down to 1MB) and upload in parallel. Set your block size based on your source file size, but if you must choose a fixed value, use 1MB. Following the above will result in significant performance gains… upwards of 10x-24x and a reduction in overall file transfer time of upwards of 90% (eg, uploading a 1GB file averaged 46.37 minutes prior to optimizations and averaged 1.86 minutes afterwards). Detail: For those of you who want more detail, or think that the claims at the end of the preceding paragraph are over-reaching, what follows is information and code supporting these claims. As the title would indicate, these tests were run from our research facility pointing to the Azure cloud (specifically US North Central as it is physically closest to us) and do not represent intra-cloud results… we have performed intra-cloud tests and the overall results are similar in notion but the data rates are significantly different as well as the tipping points for the various block sizes… this will be detailed separately). We started by building a very simple console application that would loop through a directory and upload each file to Azure storage. This application used the shipping storage client library from the 1.1 version of the azure tools. The only real variation from the client library is that we added code to collect and record the duration (in ms) and size (in bytes) for each file transferred. The code is available here. We then created a directory that had a collection of files for the following sizes: 2KB, 32KB, 64KB, 128KB, 512KB, 1MB, 5MB, 10MB, 25MB, 50MB, 100MB, 250MB, 500MB, 750MB, and 1GB (50 files for each size listed). These files contained randomly-generated binary data and do not benefit from compression (a separate discussion topic). Our file generation tool is available here. The baseline was established by running the application described above against the directory containing all of the data files. This application uploads the files in a random order so as to avoid transferring all of the files of a given size sequentially and thereby spreading the affects of periodic Internet delays across the collection of results.  We then ran some scripts to split the resulting data and generate some reports. The raw data collected for our non-optimized tests is available via the links in the Related Resources section at the bottom of this post. For each file size, we calculated the average upload time (and standard deviation) and the average transfer rate (and standard deviation). As you likely are aware, transferring data across the Internet is susceptible to many transient delays which can cause anomalies in the resulting data. It is for this reason that we randomized the order of source file processing as well as executed the tests 50x for each file size. We expect that these steps will yield a sufficiently balanced set of results. Once the baseline was collected and analyzed, we updated the test harness application with some methods to split the source file into user-defined block sizes and then to upload those blocks in parallel (using the PutBlock() method of Azure storage). The parallelization was handled by simply relying on the Parallel Extensions to .NET to provide a Parallel.For loop (see linked source for specific implementation details in Program.cs, line 173 and following… less than 100 lines total). Once all of the blocks were uploaded, we called PutBlockList() to assemble/commit the file in Azure storage. For each block transferred, the MD5 was calculated and sent ensuring that the bits that arrived matched was was intended. The timer for the blocked/parallelized transfer method wraps the entire process (source file splitting, block transfer, MD5 validation, file committal). A diagram of the process is as follows: We then tested the affects of blocking & parallelizing the transfers by running the updated application against the same source set and did a parameter sweep on the block size including 256KB, 512KB, 1MB, 2MB, and 4MB (our assumption was that anything lower than 256KB wasn’t worth the trouble and 4MB is the maximum size of a block supported by Azure). The raw data for the parallel tests is available via the links in the Related Resources section at the bottom of this post. This data was processed and then compared against the single-threaded / non-optimized transfer numbers and the results were encouraging. The Excel version of the results is available here. Two semi-obvious points need to be made prior to reviewing the data. The first is that if the block size is larger than the source file size you will end up with a “negative optimization” due to the overhead of attempting to block and parallelize. The second is that as the files get smaller, the clock-time cost of blocking and parallelizing (overhead) is more apparent and can tend towards negative optimizations. For this reason (and is supported in the raw data provided in the linked worksheet) the charts and dialog below ignore source file sizes less than 1MB. (click chart for full size image) The chart above illustrates some interesting points about the results: When the block size is smaller than the source file, performance increases but as the block size approaches and then passes the source file size, you see decreasing benefit to the point of negative gains (see the values for the 1MB file size) For some of the moderately-sized source files, small blocks (256KB) are best As the size of the source file gets larger (see values for 50MB and up), the smallest block size is not the most efficient (presumably due, at least in part, to the increased number of blocks, increased number of individual transfer requests, and reassembly/committal costs). Once you pass the 250MB source file size, the difference in rate for 1MB to 4MB blocks is more-or-less constant The 1MB block size gives the best average improvement (~16x) but the optimal approach would be to vary the block size based on the size of the source file.    (click chart for full size image) The above is another view of the same data as the prior chart just with the axis changed (x-axis represents file size and plotted data shows improvement by block size). It again highlights the fact that the 1MB block size is probably the best overall size but highlights the benefits of some of the other block sizes at different source file sizes. This last chart shows the change in total duration of the file uploads based on different block sizes for the source file sizes. Nothing really new here other than this view of the data highlights the negative affects of poorly choosing a block size for smaller files.   Summary What we have found so far is that blocking your file uploads and uploading them in parallel results in significant performance improvements. Further, utilizing extension methods and the Task Parallel Library (.NET 4.0) make short work of altering the shipping client library to provide this functionality while minimizing the amount of change to existing applications that might be using the client library for other interactions.   Related Resources Source code for upload test application Source code for random file generator ODatas feed of raw data from non-optimized transfer tests Experiment Metadata Experiment Datasets 2KB Uploads 32KB Uploads 64KB Uploads 128KB Uploads 256KB Uploads 512KB Uploads 1MB Uploads 5MB Uploads 10MB Uploads 25MB Uploads 50MB Uploads 100MB Uploads 250MB Uploads 500MB Uploads 750MB Uploads 1GB Uploads Raw Data OData feeds of raw data from blocked/parallelized transfer tests Experiment Metadata Experiment Datasets Raw Data 256KB Blocks 512KB Blocks 1MB Blocks 2MB Blocks 4MB Blocks Excel worksheet showing summarizations and comparisons

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• Spacewalk 2.0 provided to manage Oracle Linux systems

  - by wcoekaer

  Oracle Linux customers have a few options to manage and provision their servers. We provide a license to use Oracle Enterprise Manager's Linux OS management, monitoring and provisioning features without additional cost for every server that has an Oracle Linux support subscription. So there is no additional pack to license and no additional per server cost, it's all included in our Basic, Premier and Systems support subscriptions. The nice thing with Oracle Enterprise Manager is that you end up with a single management product that can manage all aspects of your software stack. You have complete insight into the applications running, you have roles and responsibilities, you have third party connectors for storage or other products and it makes it very easy and convenient to correlate data and events when something happens. If you use Oracle VM as well, you end up with a complete cloud portal with selfservice, chargeback, etc... Another, much simpler option, is just using yum. It is very easy to take a server and create directories and expose these through apache as repositories. You can have a simple yum config on each server pointing to a few specific repositories. It requires some manual effort in terms of creating directories, downloading packages and creating local repo files but it's easy to do and for many people a preferred solution. There are also a good number of customers that just connect their servers directly to ULN or to our free update server public-yum. Just to re-iterate, our public-yum servers have all the errata and updates available for free. Now we added another option. Many of our customers have switched from a competing Linux vendor and they had familiarity with their management tools. Switching to Oracle for support is very easy since we don't require changes to the installed servers but we also want to make sure there is a very easy and almost transparent switch for the management tools as well. While Oracle Enterprise Manager is our preferred way of managing systems, we now are offering Spacewalk 2.0 to our customers. The community project can be found here. We have made a few changes to ensure easy and complete support for Oracle Linux, tested it with public-yum, etc.. You can find the rpms in our public-yum repos at http://public-yum.oracle.com/repo/OracleLinux/OL6/. There are repositories for spacewalk server and then for each version (OL5,OL6) and architecture (x86 and x86-64) we have the client repositories as well. Spacewalk itself is only made available for OL6 x86-64. Documentation can be found here. I set it up myself and here are some quick steps on how you can get going in just a matter of minutes: Spacewalk Server Installation : 1) Installing an Oracle Database Use an existing Oracle Database or install a new Oracle Database (Standard or Enterprise Edition) [at this time use 11g, we will add support for 12c in the near future]. This database can be installed on the spacewalk server or on a separate remote server. While Oracle XE might work to create a small sample POC, we do not support the use of Oracle XE, spacewalk repositories can become large and create a significant database workload. Customers can use their existing database licenses, they can download the database with a trial licence from http://edelivery.oracle.com or Oracle Linux subscribers (customers) will be allowed to use the Oracle Database as a spacewalk repository as part of their Oracle Linux subscription at no additional cost. |NOTE : spacewalk requires the database to be configured with the UTF8 characterset. |Installation will fail if your database does not use UTF8. |To verify if your database is configured correctly, run the following command in sqlplus: | |select value from nls_database_parameters where parameter='NLS_CHARACTERSET'; |This should return 'AL32UTF8' 2) Configure the database schema for spacewalk Ideally, create a tablespace in the database to hold the spacewalk schema tables/data; create tablespace spacewalk datafile '/u01/app/oracle/oradata/orcl/spacewalk.dbf' size 10G autoextend on; Create the database user spacewalk (or use some other schema name) in sqlplus. example : create user spacewalk identified by spacewalk; grant connect, resource to spacewalk; grant create table, create trigger, create synonym, create view, alter session to spacewalk; grant unlimited tablespace to spacewalk; alter user spacewalk default tablespace spacewalk; 4) Spacewalk installation and configuration Spacewalk server requires an Oracle Linux 6 x86-64 system. Clients can be Oracle Linux 5 or 6, both 32- and 64bit. The server is only supported on OL6/64bit. The easiest way to get started is to do a 'Minimal' install of Oracle Linux on a server and configure the yum repository to include the spacewalk repo from public-yum. Once you have a system with a minimal install, modify your yum repo to include the spacewalk repo. Example : edit /etc/yum.repos.d/public-yum-ol.repo and add the following lines at the end of the file : [spacewalk] name=spacewalk baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL6/spacewalk20/server/$basearch/ gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 gpgcheck=1 enabled=1 Install the following pre-requisite packages on your spacewalk server : oracle-instantclient11.2-basic-11.2.0.3.0-1.x86_64 oracle-instantclient11.2-sqlplus-11.2.0.3.0-1.x86_64 rpm -ivh oracle-instantclient11.2-basic-11.2.0.3.0-1.x86_64 rpm -ivh oracle-instantclient11.2-sqlplus-11.2.0.3.0-1.x86_64 The above RPMs can be found on the Oracle Technology Network website : http://www.oracle.com/technetwork/topics/linuxx86-64soft-092277.html As the root user, configure the library path to include the Oracle Instant Client libraries : cd /etc/ld.so.conf.d echo /usr/lib/oracle/11.2/client64/lib oracle-instantclient11.2.conf ldconfig Install spacewalk : # yum install spacewalk-oracle The above yum command should download and install all required packages to run spacewalk on your local server. | NOTE : if you did a full, desktop or workstation installation, | you have to remove the JTA package | BEFORE installing spacewalk-oracle (rpm -e --nodeps jta) Once the installation completes, simply run the spacewalk configuration tool and you are all set. (make sure to run the command with the 2 arguments) spacewalk-setup --disconnected --external-db Answer the questions during the setup, ensure you provide the current database user (example : spacewalk) and password (example : spacewalk) and database server hostname (the standard hostname of the server on which you have deployed the Oracle database) At the end of the setup script, your spacewalk server should be fully configured and you can log into the web portal. Use your favorite browser to connect to the website : http://[spacewalkserverhostname] The very first action will be to create the main admin account.

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• The Sensemaking Spectrum for Business Analytics: Translating from Data to Business Through Analysis

  - by Joe Lamantia

  One of the most compelling outcomes of our strategic research efforts over the past several years is a growing vocabulary that articulates our cumulative understanding of the deep structure of the domains of discovery and business analytics. Modes are one example of the deep structure we’ve found.  After looking at discovery activities across a very wide range of industries, question types, business needs, and problem solving approaches, we've identified distinct and recurring kinds of sensemaking activity, independent of context.  We label these activities Modes: Explore, compare, and comprehend are three of the nine recognizable modes.  Modes describe *how* people go about realizing insights.  (Read more about the programmatic research and formal academic grounding and discussion of the modes here: https://www.researchgate.net/publication/235971352_A_Taxonomy_of_Enterprise_Search_and_Discovery) By analogy to languages, modes are the 'verbs' of discovery activity.  When applied to the practical questions of product strategy and development, the modes of discovery allow one to identify what kinds of analytical activity a product, platform, or solution needs to support across a spread of usage scenarios, and then make concrete and well-informed decisions about every aspect of the solution, from high-level capabilities, to which specific types of information visualizations better enable these scenarios for the types of data users will analyze. The modes are a powerful generative tool for product making, but if you've spent time with young children, or had a really bad hangover (or both at the same time...), you understand the difficult of communicating using only verbs.  So I'm happy to share that we've found traction on another facet of the deep structure of discovery and business analytics.  Continuing the language analogy, we've identified some of the ‘nouns’ in the language of discovery: specifically, the consistently recurring aspects of a business that people are looking for insight into.  We call these discovery Subjects, since they identify *what* people focus on during discovery efforts, rather than *how* they go about discovery as with the Modes. Defining the collection of Subjects people repeatedly focus on allows us to understand and articulate sense making needs and activity in more specific, consistent, and complete fashion.  In combination with the Modes, we can use Subjects to concretely identify and define scenarios that describe people’s analytical needs and goals.  For example, a scenario such as ‘Explore [a Mode] the attrition rates [a Measure, one type of Subject] of our largest customers [Entities, another type of Subject] clearly captures the nature of the activity — exploration of trends vs. deep analysis of underlying factors — and the central focus — attrition rates for customers above a certain set of size criteria — from which follow many of the specifics needed to address this scenario in terms of data, analytical tools, and methods. We can also use Subjects to translate effectively between the different perspectives that shape discovery efforts, reducing ambiguity and increasing impact on both sides the perspective divide.  For example, from the language of business, which often motivates analytical work by asking questions in business terms, to the perspective of analysis.  The question posed to a Data Scientist or analyst may be something like “Why are sales of our new kinds of potato chips to our largest customers fluctuating unexpectedly this year?” or “Where can innovate, by expanding our product portfolio to meet unmet needs?”.  Analysts translate questions and beliefs like these into one or more empirical discovery efforts that more formally and granularly indicate the plan, methods, tools, and desired outcomes of analysis.  From the perspective of analysis this second question might become, “Which customer needs of type ‘A', identified and measured in terms of ‘B’, that are not directly or indirectly addressed by any of our current products, offer 'X' potential for ‘Y' positive return on the investment ‘Z' required to launch a new offering, in time frame ‘W’?  And how do these compare to each other?”.  Translation also happens from the perspective of analysis to the perspective of data; in terms of availability, quality, completeness, format, volume, etc. By implication, we are proposing that most working organizations — small and large, for profit and non-profit, domestic and international, and in the majority of industries — can be described for analytical purposes using this collection of Subjects.  This is a bold claim, but simplified articulation of complexity is one of the primary goals of sensemaking frameworks such as this one.  (And, yes, this is in fact a framework for making sense of sensemaking as a category of activity - but we’re not considering the recursive aspects of this exercise at the moment.) Compellingly, we can place the collection of subjects on a single continuum — we call it the Sensemaking Spectrum — that simply and coherently illustrates some of the most important relationships between the different types of Subjects, and also illuminates several of the fundamental dynamics shaping business analytics as a domain.  As a corollary, the Sensemaking Spectrum also suggests innovation opportunities for products and services related to business analytics. The first illustration below shows Subjects arrayed along the Sensemaking Spectrum; the second illustration presents examples of each kind of Subject.  Subjects appear in colors ranging from blue to reddish-orange, reflecting their place along the Spectrum, which indicates whether a Subject addresses more the viewpoint of systems and data (Data centric and blue), or people (User centric and orange).  This axis is shown explicitly above the Spectrum.  Annotations suggest how Subjects align with the three significant perspectives of Data, Analysis, and Business that shape business analytics activity.  This rendering makes explicit the translation and bridging function of Analysts as a role, and analysis as an activity. Subjects are best understood as fuzzy categories [http://georgelakoff.files.wordpress.com/2011/01/hedges-a-study-in-meaning-criteria-and-the-logic-of-fuzzy-concepts-journal-of-philosophical-logic-2-lakoff-19731.pdf], rather than tightly defined buckets.  For each Subject, we suggest some of the most common examples: Entities may be physical things such as named products, or locations (a building, or a city); they could be Concepts, such as satisfaction; or they could be Relationships between entities, such as the variety of possible connections that define linkage in social networks.  Likewise, Events may indicate a time and place in the dictionary sense; or they may be Transactions involving named entities; or take the form of Signals, such as ‘some Measure had some value at some time’ - what many enterprises understand as alerts.   The central story of the Spectrum is that though consumers of analytical insights (represented here by the Business perspective) need to work in terms of Subjects that are directly meaningful to their perspective — such as Themes, Plans, and Goals — the working realities of data (condition, structure, availability, completeness, cost) and the changing nature of most discovery efforts make direct engagement with source data in this fashion impossible.  Accordingly, business analytics as a domain is structured around the fundamental assumption that sense making depends on analytical transformation of data.  Analytical activity incrementally synthesizes more complex and larger scope Subjects from data in its starting condition, accumulating insight (and value) by moving through a progression of stages in which increasingly meaningful Subjects are iteratively synthesized from the data, and recombined with other Subjects.  The end goal of  ‘laddering’ successive transformations is to enable sense making from the business perspective, rather than the analytical perspective.Synthesis through laddering is typically accomplished by specialized Analysts using dedicated tools and methods. Beginning with some motivating question such as seeking opportunities to increase the efficiency (a Theme) of fulfillment processes to reach some level of profitability by the end of the year (Plan), Analysts will iteratively wrangle and transform source data Records, Values and Attributes into recognizable Entities, such as Products, that can be combined with Measures or other data into the Events (shipment of orders) that indicate the workings of the business.  More complex Subjects (to the right of the Spectrum) are composed of or make reference to less complex Subjects: a business Process such as Fulfillment will include Activities such as confirming, packing, and then shipping orders.  These Activities occur within or are conducted by organizational units such as teams of staff or partner firms (Networks), composed of Entities which are structured via Relationships, such as supplier and buyer.  The fulfillment process will involve other types of Entities, such as the products or services the business provides.  The success of the fulfillment process overall may be judged according to a sophisticated operating efficiency Model, which includes tiered Measures of business activity and health for the transactions and activities included.  All of this may be interpreted through an understanding of the operational domain of the businesses supply chain (a Domain).   We'll discuss the Spectrum in more depth in succeeding posts.

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• Moving from Tortoise to TFS

  - by MarkPearl

  The Past A few years ago my small software company made the jump from storing code on a shared folder to source code control. At the time we had evaluated a few of the options and settled on Tortoise SVN. The main motivation for going the SVN route was that we found a great plugin for Visual Studio that allowed us to avoid the command prompt for uploading changes (like I said we are windows programmers… command prompt bad!! ) and it was free. Up to now we have been pretty happy with SVN as it removed many of the worries that I had about how safe my code was on a shared folder and also gave us the opportunity to safely have several developers work on the same project at the same time. The only times when we have been unhappy has been when we have had SVN hell days – which pretty much occur when you are doing something out of the norm and suddenly SVN just won’t resolve conflicts or something along those lines. This happens once every 4 or 5 months and is not necessarily a problem caused directly by SVN – but a problem augmented by SVN. When you have SVN hell days you want to curse SVN! With that in mind I recently have been relooking at our source code control. I have explored using GIT and was very impressed by it and have also looked at TFS. From a source code control perspective I don’t want to get into a heated discussion on which one is better – but I do want to mention that I wear two hats in my organization – software developer & manager, and with the manager hat on I tend to sway the TFS route. So when I was given a coupon to test DiscountASP.Net Team Foundation Server Service for a year, I thought it was the perfect opportunity to try TFS in a distributed environment and also make the first step towards having an integrated development management system. Some of the things that appeal to me about DiscountASP’s offering are the following… Basic management / planning facilities like to do lists inside Visual Studio Daily backup of data on the server – we are developers, not IT managers and so the more of this I could outsource the better Distributed solution – all of us work remotely and so this was a big one as well. Registering and Setting Up with DiscountASP.NET The whole registration process was simple and intuitive. The web interface is not the most visually impressive one, but it is functional and a few seconds after I clicked the last submit button a email was sitting in my inbox giving me my control panel username and suggesting that I read the “Getting Started” article. The getting started article was easy to read and understand so no complaints there either. Next to set my dev environment to work. With a few references to the getting started article I had completed the whole setup process in a matter of minutes. Ten minutes after initiating the whole thing I was logged into VS2010 and creating my first TFS project. With the service that I signed up for, I have access for 5 users – which is sufficient for my internal needs. So from what I can tell, to set the rest of us up on the system I just need to supply them with their user credentials and url. My Concerns Resolved 1) Security So, a few concerns I had about the service. First and foremost – is it secure? I would hate for someone to get access to our code and the whole idea of putting it up on the internet is a concern for me. Turning to the Knowledge Base on the DiscountASP website this is one of the first question I can see answered. According to them it is secure. I have extracted their comment below regarding this. Our TFS hosting service is secure. We only accept HTTPS connections ensuring that any client-server data transmission is encrypted. At the network level, all of our systems are protected by multiple Juniper firewalls, Tipping Point's Intrusion Detection System (see Tipping Point's case study of our use here), and we also employ DDoS mitigation to add extra layers of security. Additionally, physical access to the servers is tightly restricted. Please see the security section of this Knowledge Base article for further details. 2) Web Portal Access The other big concern I have is regarding web portal access. In the ideal world I would like to be able to give my end users access to a web portal for reporting bugs etc. When I initially read through the FAQ of the site it mentioned that there was web portal access – but from what I can see this is just for “users”. Since I am limited to 5 users for the account, it would not be practical to set up external users that we could get feedback from on bugs etc. I would be interested if this is possible – and if so if someone could post it in the comments it would be much appreciated. If this isn’t possible, it is a slight let down as we rely heavily on end user feedback to get feedback and it would have been ideal to have gotten this within the service. Other than those two items, I didn’t have any real concerns that were unresolved. So where do I go from here? So time passed by from the initial writing of this post and as work whirred in and out of my inbox I have still not had a proper opportunity to give the service a test run. Recently though things have began to slow down and then surprise surprise I had another SVN Hell day. With that experience I had a new found resolve to get our team on TFS and so today we are going to start to use the service as a team. I am hoping that I do not have TFS hell days – but if I do, I will be sure to write about them. In short - the verdict is still out on whether this service is going to be invaluable to my business or whether it will create more headaches than it is worth BUT I am hopping it will be an invaluable service. I will only really be able to determine that in a few months… till then!

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• Refactoring Part 1 : Intuitive Investments

  - by Wes McClure

  Fear, it’s what turns maintaining applications into a nightmare.  Technology moves on, teams move on, someone is left to operate the application, what was green is now perceived brown.  Eventually the business will evolve and changes will need to be made.  The approach to those changes often dictates the long term viability of the application.  Fear of change, lack of passion and a lack of interest in understanding the domain often leads to a paranoia to do anything that doesn’t involve duct tape and bailing twine.  Don’t get me wrong, those have a place in the short term viability of a project but they don’t have a place in the long term.  Add to it “us versus them” in regards to the original team and those that maintain it, internal politics and other factors and you have a recipe for disaster.  This results in code that quickly becomes unmanageable.  Even the most clever of designs will eventually become sub optimal and debt will amount that exponentially makes changes difficult.  This is where refactoring comes in, and it’s something I’m very passionate about.  Refactoring is about improving the process whereby we make change, it’s an exponential investment in the process of change. Without it we will incur exponential complexity that halts productivity. Investments, especially in the long term, require intuition and reflection.  How can we tackle new development effectively via evolving the original design and paying off debt that has been incurred? The longer we wait to ask and answer this question, the more it will cost us.  Small requests don’t warrant big changes, but realizing when changes now will pay off in the long term, and especially in the short term, is valuable. I have done my fair share of maintaining applications and continuously refactoring as needed, but recently I’ve begun work on a project that hasn’t had much debt, if any, paid down in years.  This is the first in a series of blog posts to try to capture the process which is largely driven by intuition of smaller refactorings from other projects. Signs that refactoring could help: Testability How can decreasing test time not pay dividends? One of the first things I found was that a very important piece often takes 30+ minutes to test.  I can only imagine how much time this has cost historically, but more importantly the time it might cost in the coming weeks: I estimate at least 10-20 hours per person!  This is simply unacceptable for almost any situation.  As it turns out, about 6 hours of working with this part of the application and I was able to cut the time down to under 30 seconds!  In less than the lost time of one week, I was able to fix the problem for all future weeks! If we can’t test fast then we can’t change fast, nor with confidence. Code is used by end users and it’s also used by developers, consider your own needs in terms of the code base.  Adding logic to enable/disable features during testing can help decouple parts of an application and lead to massive improvements.  What exactly is so wrong about test code in real code?  Often, these become features for operators and sometimes end users.  If you cannot run an integration test within a test runner in your IDE, it’s time to refactor. Readability Are variables named meaningfully via a ubiquitous language? Is the code segmented functionally or behaviorally so as to minimize the complexity of any one area? Are aspects properly segmented to avoid confusion (security, logging, transactions, translations, dependency management etc) Is the code declarative (what) or imperative (how)?  What matters, not how.  LINQ is a great abstraction of the what, not how, of collection manipulation.  The Reactive framework is a great example of the what, not how, of managing streams of data. Are constants abstracted and named, or are they just inline? Do people constantly bitch about the code/design? If the code is hard to understand, it will be hard to change with confidence.  It’s a large undertaking if the original designers didn’t pay much attention to readability and as such will never be done to “completion.”  Make sure not to go over board, instead use this as you change an application, not in lieu of changes (like with testability). Complexity Simplicity will never be achieved, it’s highly subjective.  That said, a lot of code can be significantly simplified, tidy it up as you go.  Refactoring will often converge upon a simplification step after enough time, keep an eye out for this. Understandability In the process of changing code, one often gains a better understanding of it.  Refactoring code is a good way to learn how it works.  However, it’s usually best in combination with other reasons, in effect killing two birds with one stone.  Often this is done when readability is poor, in which case understandability is usually poor as well.  In the large undertaking we are making with this legacy application, we will be replacing it.  Therefore, understanding all of its features is important and this refactoring technique will come in very handy. Unused code How can deleting things not help? This is a freebie in refactoring, it’s very easy to detect with modern tools, especially in statically typed languages.  We have VCS for a reason, if in doubt, delete it out (ok that was cheesy)! If you don’t know where to start when refactoring, this is an excellent starting point! Duplication Do not pray and sacrifice to the anti-duplication gods, there are excellent examples where consolidated code is a horrible idea, usually with divergent domains.  That said, mediocre developers live by copy/paste.  Other times features converge and aren’t combined.  Tools for finding similar code are great in the example of copy/paste problems.  Knowledge of the domain helps identify convergent concepts that often lead to convergent solutions and will give intuition for where to look for conceptual repetition. 80/20 and the Boy Scouts It’s often said that 80% of the time 20% of the application is used most.  These tend to be the parts that are changed.  There are also parts of the code where 80% of the time is spent changing 20% (probably for all the refactoring smells above).  I focus on these areas any time I make a change and follow the philosophy of the Boy Scout in cleaning up more than I messed up.  If I spend 2 hours changing an application, in the 20%, I’ll always spend at least 15 minutes cleaning it or nearby areas. This gives a huge productivity edge on developers that don’t. Ironically after a short period of time the 20% shrinks enough that we don’t have to spend 80% of our time there and can move on to other areas.   Refactoring is highly subjective, never attempt to refactor to completion!  Learn to be comfortable with leaving one part of the application in a better state than others.  It’s an evolution, not a revolution.  These are some simple areas to look into when making changes and can help get one started in the process.  I’ve often found that refactoring is a convergent process towards simplicity that sometimes spans a few hours but often can lead to massive simplifications over the timespan of weeks and months of regular development.

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• Not attending the LUGM mini-meetup - 05. Oct 2013

  Not attending a meeting of the LUGM can be fun, too. It's getting a bit of a habit that Ish is organising small gatherings, aka mini-meetups, of the Linux User Group Mauritius/Meta (LUGM) almost every Saturday. There they mainly discuss and talk about various elements of using Linux as ones main operating systems and the possibilities you are going to have. On top of course, some tips & tricks about mastering the command line and initial steps in scripting or even writing HTML. In general, sounds like a good portion of fun and great spirit of community. Unfortunately, I'm usually quite busy with private and family matters during the weekend and so I already signalised that I wouldn't be around. Well, at least not physically... But this Saturday a couple of things worked out faster than expected and so I was hanging out on my machine. I made virtual contact with one of Pawan's messages over on Facebook... And somehow that kicked off some kind of an online game fun on basic configuration of Apache HTTPd 2.2.x, PHP 5.x and how to improve the overall performance of a newly installed blog based on WordPress. Default configuration files Nitin's website finally came alive and despite the dark theme and the hidden Apple 'fanboy' advertisement I was more interested in the technical situation. As with any new installation there is usually quite some adjustment to be done. And Nitin's page was no exception. Unfortunately, out of the box installations of Apache httpd and PHP are too verbose and expose too much information under the hood. You might think that this isn't really a problem at all, well, think about it again after completely reading this article. First, I checked the HTTP response headers - using either Chrome Developer Tools or Firefox Web Developer extension - of Nitin's page and based on that I advised him to lower the noise levels a little bit. It's not really necessary that detailed information about web server software and scripting language has to be published in every response made. Quite a number of script kiddies and exploits actually check for version specifics prior to an attack. So, removing at least version details hardens the system a little bit. In particular, I'm talking about these response values: Server X-Powered-By How to achieve that? By tweaking the configuration files... Namely, we are going to look into the following ones: apache2.conf httpd.conf .htaccess php.ini The above list contains some additional files, I'm talking about in the next paragraphs. Anyway, those are the ones involved. Tweaking Apache Open your favourite text editor and start to modify the apache2.conf. Eventually, you might like to have a quick peak at the file to see whether it is necessary to adjust it or not. Following is a handy combination of commands to get an overview of your active directives: # sudo grep -v '#' /etc/apache2/apache2.conf | grep -v '^$' | less There you keep an eye on those two Apache directives: ServerSignature Off ServerTokens Prod If that's not the case, change them as highlighted above. In order to activate your modifications you have to restart Apache httpd server. On Debian and Ubuntu you might use apache2ctl for that, on other distributions you might have to use service or run the init-scripts again: # sudo apache2ctl configtestSyntax OK# sudo apache2ctl restart Refresh your website and check the HTTP response header. Tweaking PHP5 (a little bit) Next, check your php.ini file with the following statement: # sudo grep -v ';' /etc/php5/apache2/php.ini | grep -v '^$' | less And check the value of expose_php = Off Again, if it's not as highlighted, change it... Some more Apache love Okay, back to Apache it might also be interesting to improve the situation about browser caching and removing more obsolete information. When you run your website against the usual performance checks like Google Page Speed and Yahoo YSlow you might see those check points with bad grades on a standard, default configuration. Well, this can be done easily. Configure entity tags (ETags) ETags are only interesting when you run your websites on a farm of multiple web servers. Removing this data for your static resources is very simple in Apache. As we are going to deal with the HTTP response header information you have to ensure that Apache is capable to manipulate them. First, check your enabled modules: # sudo ls -al /etc/apache2/mods-enabled/ | grep headers And in case that the 'headers' module is not listed, you have to enable it from the available ones: # sudo a2enmod headers Second, check your httpd.conf file (in case it exists): # sudo grep -v '#' /etc/apache2/httpd.conf | grep -v '^$' | less In newer (better said fresh) installations you might have to create a new configuration file below your conf.d folder with your favourite text editor like so: # sudo nano /etc/apache2/conf.d/headers.conf Then, in order to tweak your HTTP responses either check for those lines or add them: Header unset ETagFileETag None In case that your file doesn't exist or those lines are missing, feel free to create/add them. Afterwards, check your Apache configuration syntax and restart your running instances as already shown above: # sudo apache2ctl configtestSyntax OK# sudo apache2ctl restart Add Expires headers To improve the loading performance of your website, you should take some care into the proper configuration of how to leverage the browser's ability to cache certain resources and files. This is done by adding an Expires: value to the HTTP response header. Generally speaking it is advised that you specify a near-future, read: 1 week or a little bit more, for your static content like JavaScript files or Cascading Style Sheets. One solution to adjust this is to put some instructions into the .htaccess file in the root folder of your web site. Of course, this could also be placed into a more generic location of your Apache installation but honestly, I'd like to keep this at the web site level. Following some adjustments I'm currently using on this blog site: # Turn on Expires and set default to 0ExpiresActive OnExpiresDefault A0 # Set up caching on media files for 1 year (forever?)<FilesMatch "\.(flv|ico|pdf|avi|mov|ppt|doc|mp3|wmv|wav)$">ExpiresDefault A29030400Header append Cache-Control "public"</FilesMatch> # Set up caching on media files for 1 week<FilesMatch "\.(js|css)$">ExpiresDefault A604800Header append Cache-Control "public"</FilesMatch> # Set up caching on media files for 31 days<FilesMatch "\.(gif|jpg|jpeg|png|swf)$">ExpiresDefault A2678400Header append Cache-Control "public"</FilesMatch> As we are editing the .htaccess files, it is not necessary to restart Apache. In case that your web site doesn't load anymore or you're experiencing an error while trying to restart your httpd, check that the 'expires' module is actually an enabled module: # ls -al /etc/apache2/mods-enabled/ | grep expires# sudo a2enmod expires Of course, the instructions above a re not feature complete but I hope that they might provide a better default configuration for your LAMP stack. Resume of the day Within a couple of hours, and while being occupied with an eLearning course on SQL Server 2012, I had some good fun in helping and assisting other LUGM members while they were some kilometers away at Bagatelle. According to other blog articles it seems that Nitin had quite some moments of desperation. Just for the records: At no time it was my intention to either kick his butt or pull a leg on him. Simply, providing some input based on the lessons I've learned over the last couple of years configuring Apache HTTPd and PHP. Check out the other blogs, too: LUGM mini-meetup... Epic! Superb Saturday Linux Meetup And last but not least, the man himself: The end of a new beginning Cheers, and happy community'ing! Updates Due to our weekly Code & Coffee sessions in the MSCC community, I had a chance to talk to Nitin directly and he showed me the problems directly on his machine. This led to update this article hence the paragraphs on enabling the modules 'headers' and 'expires'.

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• When is a Seek not a Seek?

  - by Paul White

  The following script creates a single-column clustered table containing the integers from 1 to 1,000 inclusive. IF OBJECT_ID(N'tempdb..#Test', N'U') IS NOT NULL DROP TABLE #Test ; GO CREATE TABLE #Test ( id INTEGER PRIMARY KEY CLUSTERED ); ; INSERT #Test (id) SELECT V.number FROM master.dbo.spt_values AS V WHERE V.[type] = N'P' AND V.number BETWEEN 1 AND 1000 ; Let’s say we need to find the rows with values from 100 to 170, excluding any values that divide exactly by 10.  One way to write that query would be: SELECT T.id FROM #Test AS T WHERE T.id IN ( 101,102,103,104,105,106,107,108,109, 111,112,113,114,115,116,117,118,119, 121,122,123,124,125,126,127,128,129, 131,132,133,134,135,136,137,138,139, 141,142,143,144,145,146,147,148,149, 151,152,153,154,155,156,157,158,159, 161,162,163,164,165,166,167,168,169 ) ; That query produces a pretty efficient-looking query plan: Knowing that the source column is defined as an INTEGER, we could also express the query this way: SELECT T.id FROM #Test AS T WHERE T.id >= 101 AND T.id <= 169 AND T.id % 10 > 0 ; We get a similar-looking plan: If you look closely, you might notice that the line connecting the two icons is a little thinner than before.  The first query is estimated to produce 61.9167 rows – very close to the 63 rows we know the query will return.  The second query presents a tougher challenge for SQL Server because it doesn’t know how to predict the selectivity of the modulo expression (T.id % 10 > 0).  Without that last line, the second query is estimated to produce 68.1667 rows – a slight overestimate.  Adding the opaque modulo expression results in SQL Server guessing at the selectivity.  As you may know, the selectivity guess for a greater-than operation is 30%, so the final estimate is 30% of 68.1667, which comes to 20.45 rows. The second difference is that the Clustered Index Seek is costed at 99% of the estimated total for the statement.  For some reason, the final SELECT operator is assigned a small cost of 0.0000484 units; I have absolutely no idea why this is so, or what it models.  Nevertheless, we can compare the total cost for both queries: the first one comes in at 0.0033501 units, and the second at 0.0034054.  The important point is that the second query is costed very slightly higher than the first, even though it is expected to produce many fewer rows (20.45 versus 61.9167). If you run the two queries, they produce exactly the same results, and both complete so quickly that it is impossible to measure CPU usage for a single execution.  We can, however, compare the I/O statistics for a single run by running the queries with STATISTICS IO ON: Table '#Test'. Scan count 63, logical reads 126, physical reads 0. Table '#Test'. Scan count 01, logical reads 002, physical reads 0. The query with the IN list uses 126 logical reads (and has a ‘scan count’ of 63), while the second query form completes with just 2 logical reads (and a ‘scan count’ of 1).  It is no coincidence that 126 = 63 * 2, by the way.  It is almost as if the first query is doing 63 seeks, compared to one for the second query. In fact, that is exactly what it is doing.  There is no indication of this in the graphical plan, or the tool-tip that appears when you hover your mouse over the Clustered Index Seek icon.  To see the 63 seek operations, you have click on the Seek icon and look in the Properties window (press F4, or right-click and choose from the menu): The Seek Predicates list shows a total of 63 seek operations – one for each of the values from the IN list contained in the first query.  I have expanded the first seek node to show the details; it is seeking down the clustered index to find the entry with the value 101.  Each of the other 62 nodes expands similarly, and the same information is contained (even more verbosely) in the XML form of the plan. Each of the 63 seek operations starts at the root of the clustered index B-tree and navigates down to the leaf page that contains the sought key value.  Our table is just large enough to need a separate root page, so each seek incurs 2 logical reads (one for the root, and one for the leaf).  We can see the index depth using the INDEXPROPERTY function, or by using the a DMV: SELECT S.index_type_desc, S.index_depth FROM sys.dm_db_index_physical_stats ( DB_ID(N'tempdb'), OBJECT_ID(N'tempdb..#Test', N'U'), 1, 1, DEFAULT ) AS S ; Let’s look now at the Properties window when the Clustered Index Seek from the second query is selected: There is just one seek operation, which starts at the root of the index and navigates the B-tree looking for the first key that matches the Start range condition (id >= 101).  It then continues to read records at the leaf level of the index (following links between leaf-level pages if necessary) until it finds a row that does not meet the End range condition (id <= 169).  Every row that meets the seek range condition is also tested against the Residual Predicate highlighted above (id % 10 > 0), and is only returned if it matches that as well. You will not be surprised that the single seek (with a range scan and residual predicate) is much more efficient than 63 singleton seeks.  It is not 63 times more efficient (as the logical reads comparison would suggest), but it is around three times faster.  Let’s run both query forms 10,000 times and measure the elapsed time: DECLARE @i INTEGER, @n INTEGER = 10000, @s DATETIME = GETDATE() ; SET NOCOUNT ON; SET STATISTICS XML OFF; ; WHILE @n > 0 BEGIN SELECT @i = T.id FROM #Test AS T WHERE T.id IN ( 101,102,103,104,105,106,107,108,109, 111,112,113,114,115,116,117,118,119, 121,122,123,124,125,126,127,128,129, 131,132,133,134,135,136,137,138,139, 141,142,143,144,145,146,147,148,149, 151,152,153,154,155,156,157,158,159, 161,162,163,164,165,166,167,168,169 ) ; SET @n -= 1; END ; PRINT DATEDIFF(MILLISECOND, @s, GETDATE()) ; GO DECLARE @i INTEGER, @n INTEGER = 10000, @s DATETIME = GETDATE() ; SET NOCOUNT ON ; WHILE @n > 0 BEGIN SELECT @i = T.id FROM #Test AS T WHERE T.id >= 101 AND T.id <= 169 AND T.id % 10 > 0 ; SET @n -= 1; END ; PRINT DATEDIFF(MILLISECOND, @s, GETDATE()) ; On my laptop, running SQL Server 2008 build 4272 (SP2 CU2), the IN form of the query takes around 830ms and the range query about 300ms.  The main point of this post is not performance, however – it is meant as an introduction to the next few parts in this mini-series that will continue to explore scans and seeks in detail. When is a seek not a seek?  When it is 63 seeks © Paul White 2011 email: [email protected] twitter: @SQL_kiwi

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• DTracing TCP congestion control

  - by user12820842

  In a previous post, I showed how we can use DTrace to probe TCP receive and send window events. TCP receive and send windows are in effect both about flow-controlling how much data can be received - the receive window reflects how much data the local TCP is prepared to receive, while the send window simply reflects the size of the receive window of the peer TCP. Both then represent flow control as imposed by the receiver. However, consider that without the sender imposing flow control, and a slow link to a peer, TCP will simply fill up it's window with sent segments. Dealing with multiple TCP implementations filling their peer TCP's receive windows in this manner, busy intermediate routers may drop some of these segments, leading to timeout and retransmission, which may again lead to drops. This is termed congestion, and TCP has multiple congestion control strategies. We can see that in this example, we need to have some way of adjusting how much data we send depending on how quickly we receive acknowledgement - if we get ACKs quickly, we can safely send more segments, but if acknowledgements come slowly, we should proceed with more caution. More generally, we need to implement flow control on the send side also. Slow Start and Congestion Avoidance From RFC2581, let's examine the relevant variables: "The congestion window (cwnd) is a sender-side limit on the amount of data the sender can transmit into the network before receiving an acknowledgment (ACK). Another state variable, the slow start threshold (ssthresh), is used to determine whether the slow start or congestion avoidance algorithm is used to control data transmission" Slow start is used to probe the network's ability to handle transmission bursts both when a connection is first created and when retransmission timers fire. The latter case is important, as the fact that we have effectively lost TCP data acts as a motivator for re-probing how much data the network can handle from the sending TCP. The congestion window (cwnd) is initialized to a relatively small value, generally a low multiple of the sending maximum segment size. When slow start kicks in, we will only send that number of bytes before waiting for acknowledgement. When acknowledgements are received, the congestion window is increased in size until cwnd reaches the slow start threshold ssthresh value. For most congestion control algorithms the window increases exponentially under slow start, assuming we receive acknowledgements. We send 1 segment, receive an ACK, increase the cwnd by 1 MSS to 2*MSS, send 2 segments, receive 2 ACKs, increase the cwnd by 2*MSS to 4*MSS, send 4 segments etc. When the congestion window exceeds the slow start threshold, congestion avoidance is used instead of slow start. During congestion avoidance, the congestion window is generally updated by one MSS for each round-trip-time as opposed to each ACK, and so cwnd growth is linear instead of exponential (we may receive multiple ACKs within a single RTT). This continues until congestion is detected. If a retransmit timer fires, congestion is assumed and the ssthresh value is reset. It is reset to a fraction of the number of bytes outstanding (unacknowledged) in the network. At the same time the congestion window is reset to a single max segment size. Thus, we initiate slow start until we start receiving acknowledgements again, at which point we can eventually flip over to congestion avoidance when cwnd ssthresh. Congestion control algorithms differ most in how they handle the other indication of congestion - duplicate ACKs. A duplicate ACK is a strong indication that data has been lost, since they often come from a receiver explicitly asking for a retransmission. In some cases, a duplicate ACK may be generated at the receiver as a result of packets arriving out-of-order, so it is sensible to wait for multiple duplicate ACKs before assuming packet loss rather than out-of-order delivery. This is termed fast retransmit (i.e. retransmit without waiting for the retransmission timer to expire). Note that on Oracle Solaris 11, the congestion control method used can be customized. See here for more details. In general, 3 or more duplicate ACKs indicate packet loss and should trigger fast retransmit . It's best not to revert to slow start in this case, as the fact that the receiver knew it was missing data suggests it has received data with a higher sequence number, so we know traffic is still flowing. Falling back to slow start would be excessive therefore, so fast recovery is used instead. Observing slow start and congestion avoidance The following script counts TCP segments sent when under slow start (cwnd ssthresh). #!/usr/sbin/dtrace -s #pragma D option quiet tcp:::connect-request / start[args[1]-cs_cid] == 0/ { start[args[1]-cs_cid] = 1; } tcp:::send / start[args[1]-cs_cid] == 1 && args[3]-tcps_cwnd tcps_cwnd_ssthresh / { @c["Slow start", args[2]-ip_daddr, args[4]-tcp_dport] = count(); } tcp:::send / start[args[1]-cs_cid] == 1 && args[3]-tcps_cwnd args[3]-tcps_cwnd_ssthresh / { @c["Congestion avoidance", args[2]-ip_daddr, args[4]-tcp_dport] = count(); } As we can see the script only works on connections initiated since it is started (using the start[] associative array with the connection ID as index to set whether it's a new connection (start[cid] = 1). From there we simply differentiate send events where cwnd ssthresh (congestion avoidance). Here's the output taken when I accessed a YouTube video (where rport is 80) and from an FTP session where I put a large file onto a remote system. # dtrace -s tcp_slow_start.d ^C ALGORITHM RADDR RPORT #SEG Slow start 10.153.125.222 20 6 Slow start 138.3.237.7 80 14 Slow start 10.153.125.222 21 18 Congestion avoidance 10.153.125.222 20 1164 We see that in the case of the YouTube video, slow start was exclusively used. Most of the segments we sent in that case were likely ACKs. Compare this case - where 14 segments were sent using slow start - to the FTP case, where only 6 segments were sent before we switched to congestion avoidance for 1164 segments. In the case of the FTP session, the FTP data on port 20 was predominantly sent with congestion avoidance in operation, while the FTP session relied exclusively on slow start. For the default congestion control algorithm - "newreno" - on Solaris 11, slow start will increase the cwnd by 1 MSS for every acknowledgement received, and by 1 MSS for each RTT in congestion avoidance mode. Different pluggable congestion control algorithms operate slightly differently. For example "highspeed" will update the slow start cwnd by the number of bytes ACKed rather than the MSS. And to finish, here's a neat oneliner to visually display the distribution of congestion window values for all TCP connections to a given remote port using a quantization. In this example, only port 80 is in use and we see the majority of cwnd values for that port are in the 4096-8191 range. # dtrace -n 'tcp:::send { @q[args[4]-tcp_dport] = quantize(args[3]-tcps_cwnd); }' dtrace: description 'tcp:::send ' matched 10 probes ^C 80 value ------------- Distribution ------------- count -1 | 0 0 |@@@@@@ 5 1 | 0 2 | 0 4 | 0 8 | 0 16 | 0 32 | 0 64 | 0 128 | 0 256 | 0 512 | 0 1024 | 0 2048 |@@@@@@@@@ 8 4096 |@@@@@@@@@@@@@@@@@@@@@@@@@@ 23 8192 | 0

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• Corsair Hackers Reboot

  It wasn't easy for me to attend but it was absolutely worth to go. The Linux User Group of Mauritius (LUGM) organised another get-together for any open source enthusiast here on the island. Strangely named "Corsair Hackers Reboot" but it stands for a positive cause: "Corsair Hackers Reboot Event A collaborative activity involving LUGM, UoM Computer Club, Fortune Way Shopping Mall and several geeks from around the island, striving to put FOSS into homes & offices. The public is invited to discover and explore Free Software & Open Source." And it was a good opportunity for me and the kids to visit the east coast of Mauritius, too. Perfect timing It couldn't have been better... Why? Well, for two important reasons (in terms of IT): End of support for Microsoft Windows XP - 08.04.2014 Release of Ubuntu 14.04 Long Term Support - 17.04.2014 Quite funnily, those two IT dates weren't the initial reasons and only during the weeks of preparations we put those together. And therefore it was even more positive to promote the use of Linux and open source software in general to a broader audience. Getting there ... Thanks to the new motor way M3 and all the additional road work which has been completed recently it was very simple to get across the island in a very quick and relaxed manner. Compared to my trips in the early days of living in Mauritius (and riding on a scooter) it was very smooth and within less than an hour we hit Centrale de Flacq. Well, being in the city doesn't necessarily mean that one has arrived at the destination. But thanks to modern technology I had a quick look on Google Maps, and we finally managed to get a parking behind the huge bus terminal in Flacq. From there it was just a short walk to Fortune Way. The children were trying to count the number of buses... Well, lots and lots of buses - really impressive actually. What was presented? There were different areas set up. Right at the entrance one's attention was directly drawn towards the elevated hacker's stage. Similar to rock stars performing their gig there was bunch of computers, laptops and networking equipment in order to cater the right working conditions for coding/programming challenge(s) on the one hand and for the pen-testing or system hacking competition on the other hand. Personally, I was very impresses that actually Nitin took care of the pen-testing competition. He hardly started one year back with Linux in general, and Kali Linux specifically. Seeing his personal development from absolute newbie to a decent Linux system administrator within such a short period of time, is really impressive. His passion to open source software made him a living. Next, clock-wise seen, was the Kid's Corner with face-painting as the main attraction. Additionally, there were numerous paper print outs to colour. Plus a decent workstation with the educational suite GCompris. Of course, my little ones were into that. They already know GCompris since a while as they are allowed to use it on an IGEL thin client terminal here at home. To simplify my life, I set up GCompris as full-screen guest session on the server, and they can pass the login screen without any further obstacles. And because it's a thin client hooked up to a XDMCP remote session I don't have to worry about the hardware on their desk, too. The next section was the main attraction of the event: BYOD - Bring Your Own Device Well, compared to the usual context of BYOD the corsairs had a completely different intention. Here, you could bring your own laptop and a team of knowledgeable experts - read: geeks and so on - offered to fully convert your system on any Linux distribution of your choice. And even though I came later, I was told that the USB pen drives had been in permanent use. From being prepared via dd command over launching LiveCD session to finally installing a fresh Linux system on bare metal. Most interestingly, I did a similar job already a couple of months ago, while upgrading an existing Windows XP system to Xubuntu 13.10. So far, the female owner is very happy and enjoys her system almost every evening to go shopping online, checking mails, and reading latest news from the Anime world. Back to the Hackers event, Ish told me that they managed approximately 20 conversion during the day. Furthermore, Ajay and others gladly assisted some visitors with some tricky issues and by the end of the day you can call is a success. While I was around, there was a elderly male visitor that got a full-fledged system conversion to a Linux system running completely in French language. A little bit more to the centre it was Yasir's turn to demonstrate his Arduino hardware that he hooked up with an experimental electrical circuit board connected to an LCD matrix display. That's the real spirit of hacking, and he showed some minor adjustments on the fly while demo'ing the system. Also, very interesting there was a thermal sensor around. Personally, I think that platforms like the Arduino as well as the Raspberry Pi have a great potential at a very affordable price in order to bring a better understanding of electronics as well as computer programming to a broader audience. It would be great to see more of those experiments during future activities. And last but not least there were a small number of vendors. Amongst them was Emtel - once again as sponsor of the general internet connectivity - and another hardware supplier from Riche Terre shopping mall. They had a good collection of Android related gimmicks, like a autonomous web cam that can convert any TV with HDMI connector into an online video chat system given WiFi. It's actually kind of awesome to have a Skype or Google hangout video session on the big screen rather than on the laptop. Some pictures of the event LUGM: Great conversations on Linux, open source and free software during the Corsair Hackers Reboot LUGM: Educational workstation running GCompris suite attracted the youngest attendees of the day. Of course, face painting had to be done prior to hacking... LUGM: Nadim demoing some Linux specifics to interested visitors. Everyone was pretty busy during the whole day LUGM: The hacking competition, here pen-testing a wireless connection and access point between multiple machines LUGM: Well prepared workstations to be able to 'upgrade' visitors' machines to any Linux operating system Final thoughts Gratefully, during the preparations of the event I was invited to leave some comments or suggestions, and the team of the LUGM did a great job. The outdoor banner was a eye-catcher, the various flyers and posters for the event were clearly written and as far as I understood from the quick chats I had with Ish, Nadim, Nitin, Ajay, and of course others all were very happy about the event execution. Great job, LUGM! And I'm already looking forward to the next Corsair Hackers Reboot event ... Crossing fingers: Very soon and hopefully this year again :) Update: In the media The event had been announced in local media, too. L'Express: Salon informatique: Hacking Challenge à Flacq

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• Reviewing Retail Predictions for 2011

  - by David Dorf

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} I've been busy thinking about what 2012 and beyond will look like for retail, and I have some interesting predictions to share.  But before I go there, let’s first review this year’s predictions before making new ones for 2012. 1. Alternate Payments We've seen several alternate payment schemes emerge over the last two years, and 2011 may be the year one of them takes hold. Any competition that can drive down fees will be good for everyone. I'm betting that Apple will add NFC chips to their next version of the iPhone, then enable payments in stores using iTunes accounts on the backend. Paypal will continue to make inroads, and Isis will announce a pilot. The iPhone 4S did not contain an NFC chip, so we’ll have to continuing waiting for the iPhone 5. PayPal announced its moving into in-store payments, and Google launched its wallet in selected cities.  Overall I think the payment scene is heating up and that trend will continue. 2. Engineered Systems The industry is moving toward purpose-built appliances that are optimized across the entire stack. Oracle calls these "engineered systems" and the first two examples are Exadata and Exalogic, but there are other examples from other vendors. These are particularly important to the retail industry because of the volume of data that must be processed. There should be continued adoption in 2011. Oracle reports that Exadata is its fasting growing product, and at the recent OpenWorld it announced the SuperCluster and Exalytics products, both continuing the engineered systems trend. SAP’s HANA continues to receive attention, and IBM also seems to be moving in this direction. 3. Social Analytics There are lots of tools that provide insight into how a brand is perceived across popular internet sites, but as far as I know, these tools are not industry specific. The next step needs to mine the data and determine how it should influence retail operations. The data needs to help retailers determine how they create promotions, which products to stock, and how to keep consumers engaged. Social data alone does not provide the answers, but its one more data point that will help retailers make better decisions. Look for some vendor consolidation to help make this happen. In March, Salesforce.com acquired leading social monitoring vendor Radian6 and followed up with acquisitions of Heroku and Model Metrics. The notion of Social CRM seems to be going more mainstream now. 4. 2-D Barcodes Look for more QRCodes on shelf-tags, in newspaper circulars, and on billboards. It's a great portal from the physical world into the digital one that buys us time until augmented reality matures further. Nobody wants to type "www", backslash, and ".com" on their phones. QRCodes are everywhere. ‘Nuff said. 5. In the words of Microsoft, "To the Cloud!" My favorite "cloud application" is Evernote. If you take notes on your work laptop, you will inevitably need those notes on your home PC. And if you manage to solve that problem, you'll need to access them from your mobile phone. Evernote stores your notes in the cloud and provides easy ways to access them. Being able to access a service from anywhere and not having to worry about backups, upgrades, etc. is great. Retailers will start to rely on cloud services, both public and private, in the coming year. There were no shortage of announcements in this area: Amazon’s cloud-based Kindle Fire, Apple’s iCloud, Oracle’s Public Cloud, etc. I saw an interesting presentation showing how BevMo moved their systems to the cloud.  Seems like retailers are starting to consider the cloud for specific uses. 6. F-CommerceTop of Form Move over "E" and "M" so we can introduce "F-Commerce," which should go mainstream in 2011. Already several retailers have created small stores on Facebook, and it won't be long before Facebook becomes a full-fledged channel in the omni-channel world of retail. The battle between Facebook and Google will heat up over retail, where both stand to make lots of money. JCPenney and ASOS both put their entire catalogs on Facebook, and lots of other retailers have connected Facebook to their e-commerce site. I still think selling from the newsfeed is the best approach, and several retailers are trying that approach as well. I just don’t see Google+ as a threat to Facebook, so I think that battle is over.  I called 2011 The Year of F-Commerce, and that was probably accurate. Its good to look back at predictions, but we also have to think about what was missed.  I didn't see Amazon entering the tablet business with such a splash, although in hindsight it was obvious. Nor did I think HP would fall so far so fast.  Look for my 2012 predictions coming soon.

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• Exalogic 2.0.1 Tea Break Snippets - Creating a ModifyJeOS VirtualBox

  - by The Old Toxophilist

  Following on from my previous blog entry "Modifying the Base Template" I decided to put together a quick blog to show how to create a small VirtualBox, guest, that can be used to execute the ModifyJeOS and hence edit you templates. One of the main advantages of this is that Templates can be created away from the Exalogic Environment. For the Guest OS I chose OEL 6u3 and decided to create it as a basic server because I did not require a graphical interface but it's a simple change to create it with a GUI. Required Software Virtual Box. Oracle Enterprise Linux. Creating the VM I'll assume that the reader is experienced with Virtual Box and installing OEL and hence will make this section brief. Create VirtualBox Guest Create a new VirtualBox Guest and select oracle Linux 64 bit. Follow through the create process and select Dynamic Disk Size and the default 12GB disk size. The actual image will be a lot smaller than this but the OEL install will fail with insufficient disk space if you attempt a smaller size. Once the guest has been created attach the previously downloaded OEL 6u3 iso to the cd drive and start the guest. Install OEL On starting the guest the system will boot off the associated OEL 6u3 iso and take you through the standard installation process. Select all the appropriate information but when you reach the installation type select Basic Server because we do not need that additional packages and only need to access through the command line interface. Complete the installation and reboot the Guest. At this point we now have a basic OEL server running. Installing Guest Add-ons Before we can easily access the Guest we will need to add the VirtualBox guest add-ons. These will provide better keyboard and mouse integration and allow access the shared folders on the host machine. Before we can do this we will need to do the following: Enable Networking. Install additional rpms.  To enable the networking (eth0), that appears to be disabled by default, we can execute: ifup eth0 This will start the eth0 connection but once the Guest is rebooted the network will be down again. To resolve this you will need to edit the /etc/sysconfig/network-scripts/ifcfg-eth0 file and change the ONBOOT parameter to "yes". Now we have enabled the network we will need to install a number of addition rpm. First we will need to configure the yum repository as follows: [ol6_latest] name=Oracle Linux $releasever Latest ($basearch) baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL6/latest/$basearch/ gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 gpgcheck=1 enabled=1 [ol6_ga_base] name=Oracle Linux $releasever GA installation media copy ($basearch) baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL6/0/base/$basearch/ gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 gpgcheck=1 enabled=0 [ol6_u1_base] name=Oracle Linux $releasever Update 1 installation media copy ($basearch) baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL6/1/base/$basearch/ gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 gpgcheck=1 enabled=0 [ol6_u2_base] name=Oracle Linux $releasever Update 2 installation media copy ($basearch) baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL6/2/base/$basearch/ gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 gpgcheck=1 enabled=0 [ol6_u3_base] name=Oracle Linux $releasever Update 3 installation media copy ($basearch) baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL6/3/base/$basearch/ gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 gpgcheck=1 enabled=0 [ol6_UEK_latest] name=Latest Unbreakable Enterprise Kernel for Oracle Linux $releasever ($basearch) baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL6/UEK/latest/$basearch/ gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 gpgcheck=1 enabled=1 [ol6_UEK_base] name=Unbreakable Enterprise Kernel for Oracle Linux $releasever ($basearch) baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL6/UEK/base/$basearch/ gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 gpgcheck=1 enabled=0 Once the repository has been edited we will need to execute the following yum commands: yum update yum install gcc yum install kernel-uek-devel yum install kernel-devel yum install createrepo At this point we now have all the additional packages required to install the VirtualBox Guest Add-ons. So select Devices->InstallGuest Additions on you running guest: This will simply place the VirtualBoxGuestAdditions.iso in the virtual cd and we will need to execute the following before we can run them. mkdir /media/cdrom mount -t iso9660 -o ro /dev/cdrom /media/cdrom cd /media/cdrom/ ls ./VBoxLinuxAdditions.run This will initiate the install and kernel rebuild. What you will notice is that during the installation a Failed will be displayed but this is simply because we have no graphical components. At this point we the installation will also have added the vboxsf group to the system and to access any shared folders we will create our user will need to be a member of this group an so the next stage is to add the root user to this group as follows: usermod -G vboxsf root cat /etc/group cat /etc/passwd init 0 Now simply shutdown the guest and add the Shared folder within your guests settings. Install ModifyJeOS Once the shared folder has been added restart the guest and change directory into the shared folder (/media/sf_<folder name>). For the next step I am assuming the ModifyJeOS rpms are located in the shared folder. We can simply execute: rpm -ivh ovm-modify-jeos-1.1.0-17.el5.noarch.rpm # Test with modifyjeos Using ModifyJeOS I have a modified MountSystemImg.sh script that should be copied into the /root/bin directory (you may need to create this) and from here it can be executed from any location: MountSystemImg.sh #!/bin/sh # The script assumes it's being run from the directory containing the System.img # Export for later i.e. during unmount export LOOP=`losetup -f` export SYSTEMIMG=/mnt/elsystem export TEMPLATEDIR=`pwd` # Make Temp Mount Directory mkdir -p $SYSTEMIMG # Create Loop for the System Image losetup $LOOP System.img kpartx -a $LOOP mount /dev/mapper/`basename $LOOP`p2 $SYSTEMIMG #Change Dir into mounted Image cd $SYSTEMIMG echo "######################################################################" echo "### ###" echo "### Starting Bash shell for editing. When completed log out to ###" echo "### Unmount the System.img file. ###" echo "### ###" echo "######################################################################" echo bash cd ~ cd $TEMPLATEDIR umount $SYSTEMIMG kpartx -d $LOOP losetup -d $LOOP rm -rf $SYSTEMIMG This script will simple create a mount directory, mount the System.img and then start a new shell in the mounted directory. On exiting the shell it will unmount the System.img. It only requires that you execute the script in the directory containing the System.img. These can be created under the mounted shared directory. In the example below I have extracted the Base template within the shared folder and then renamed it OEL_40GB_ROOT before changing into that directory and executing the script.

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• Single Key Multiple Values Data Structure for one to many mapping

  - by nijhawan.saurabh

  Dictionaries are good, they are great to store Key / Value pairs but what if you want to store multiple values for a single key? Dictionaries would not allow duplicate keys. I came across a nice way to represent such a Data Structure using one of the Extension Method (ToLookup) present in System.Linq Namespace which converts an IEnumerable<T> to an ILookup<TKey, TElement>.   Now, there are two parameters this method expects (The other overload expects 3 parameters): IEnumerable<TSource> - This list would contain the actual data. Func<TSource, TKey> keySelector - The Delegate which which computes the keys   The method returns the following: ILookup<TKey, TElement>   This DS would store Keys and multiple values along those keys.   Let's see a small example:        12  using System;    13     using System.Collections.Generic;    14     using System.Linq;    15     16     /// <summary>    17     /// </summary>    18     internal class Program    19     {    20         #region Methods    21     22         /// <summary>    23         /// </summary>    24         /// <param name="args">    25         /// The args.    26         /// </param>    27         private static void Main(string[] args)    28         {    29             // Create an array of strings.    30             var list = new List<string> { "IceCream1", "Chocolate Moose", "IceCream2" };    31     32             // Generate a lookup Data Structure    33             ILookup<int, string> lookupDs = list.ToLookup(item => item.Length);    34     35           // Enumerate groupings.    36             foreach (var group in lookupDs)    37             {    38                 foreach (string element in group)    39                 {    40                     Console.WriteLine(element);    41                 }    42             }    43         } Normal 0 false false false EN-US X-NONE 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:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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