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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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• 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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• Emtel Knowledge Series - Q2/2014

  From Cyber Island to Smart Mauritius Cyber Island? Smart Mauritius? - What is Emtel talking about? "With the majority of the population living in urban environments today, the concept of "Smart Cities" has become an urgent necessity. "Smart Cities" refer to an urban transformation which, by using latest ICT technologies makes cities more efficient. Many Governments are setting out ambitious plans to build the cities of the future based on massive connectivity, high bandwidth communications, intelligent sensors and analysis of huge volumes of data. Various researches have shown four key enablers for smart city success - Government leadership, suitable technology infrastructure, solid public-private partnerships and engaged citizens. It is around these enabling factors that telecoms companies can play a vital role in assisting governments to deliver on the smart city vision." The Emtel Knowledge Series goes in compliance with Emtel's 25th anniversary celebrations throughout the year and the master of ceremony, Kim Andersen, mentioned that there will be more upcoming events on a quarterly base. As a representative of the Mauritius Software Craftsmanship Community (MSCC) there was absolutely no hesitation to join in again. Following my visit to the first Emtel Knowledge Series workshop back in February this year, it was great to have another opportunity to meet and exchange with technology experts. But quite frankly what is it with those buzz words... As far as I remember and how it was mentioned "Cyber Island" is an old initiative from around 2005/2006 which has been refreshed in 2010. It implies the empowerment of Information & Communication Technologies (ICT) as an essential factor of growth by the government here in Mauritius. Actually, the first promotional period of Cyber Island brought me here but that's another story. The venue and its own problems Like last time the event was organised and held at the Conference Hall at Cyber Tower I in Ebene. As I've been working there for some years, I know about the frustrating situation of finding a proper parking. So, does Smart Island include better solutions for the search of parking spaces? Maybe, let's see whether I will be able to answer that question at the end of the article. Anyway, after circling around the tower almost two times, I finally got a decent space to put the car, without risking to get a ticket or damage actually. International speakers and their experience Once again, Emtel did a great job to get international expertise onto the stage to share their experience and vision on this kind of embarkment. Personally, I really appreciated the fact they were speakers of global reach and could provide own-experience knowledge. Johan Gott spoke about the fundamental change that the Swedish government ignited in order to move their society and workers' environment away from heavy industry towards a knowledge-based approach. Additionally, we spoke about the effort and transformation of New York City into a greener and more efficient Smart City. Given modern technology he also advised that any kind of available Big Data should be opened to the general public - this openness would provide a playground for anyone to garner new ideas and most probably solid solutions of which no one else thought about before. Emtel Knowledge Series on moving from Cyber Island to Smart Mauritus Later during the afternoon that exact statement regarding openness to and transparency of government-owned Big Data has been emphasised again by the Danish speaker Kim Andersen and his former colleague Mika Jantunen from Finland. Mika continued to underline the important role of the government to provide a solid foundation for a knowledge-based society and mentioned that Finnish citizens have a constitutional right to broadband connectivity. Next to free higher (tertiary) education Finland already produced a good number of innovations, among them are: First country to grant voting rights to women Free higher education Constitutional right to broadband connectivity Nokia Linux Angry Birds Sauna and others...  General access to internet via broadband and/or mobile connectivity is surely a key factor towards Smart Cities, or better said Smart Mauritius given the area dimensions and size of population. CTO Paul Valette gave the audience a brief overview of the essential role that Emtel will have to move Mauritius forward towards a knowledge-based and innovation-driven environment for its citizen. What I have seen looks really promising and with recently published information that Mauritians have 127% of mobile capacity - meaning more than 1 mobile, smartphone or tablet per person - it will be crucial to have the right infrastructure for these connected devices. How would it be possible to achieve a knowledge-based society? YouTube to the rescue!Seriously, gaining more knowledge will require to have fast access to educational course material as explained by Dr Kaviraj Sukon, General Director of the Open University of Mauritius. According to him a good number of high-profile universities in the world have opened their course libraries to the general public, among them EDX, Coursera and Open University. Nowadays, you're actually able and enabled to learn for and earn a BSc or even MSc certification on your own pace - no need to attend classed on campus. It was really impressive to see the number of available hours - more than enough for a life-long learning experience! {loadposition content_adsense} Networking in the name of MSCC As briefly mentioned above I was about to combine two approaches for this workshop. Of course, getting latest information and updates on Emtel services available, especially for my business here on the west coast of the island, but also to meet and greet new people for the MSCC. And I think it was very positive on both sides. Let me quickly describe some of the key aspects that happened during the day: Met with Arnaud Meslier and Kellie, both Microsoft to swap latest information on IT events. Hereby, I got an invite to Microsoft Windows Phone 8.1 Dev Camp. Got in touch with Arvin Lockee, Emtel to check our options to meet with the data team, and seizing the opportunity to have a visiting tour at the Emtel Data Centre. Had a great chat with Avinash Meetoo, Knowledge 7, Kim Andersen and Mika Jantunen about the situation of teaching and learning in general and specifically in the private sector here in Mauritius. Additionally, a number of various other interesting chats... Once again, I'm catching up on a couple of business cards in order to provide more background information about the MSCC, and to create a better awareness of MSCC within the local IT businesses. There is more to come soon!  Resume of the day The number of attendees during this event has been doubled or even tripled this time. The whole organisation has been improved massively and the combination of presentation and summarizing panel discussions was better than during the previous workshop back in February. Overall, once again a well-organised workshop and I'm already looking forward to join the next workshop in Q3. Update End of July we finally managed to visit the Emtel Data Centre in Arsenal. It was an interesting opportunity for some of our MSCC members.

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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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• elffile: ELF Specific File Identification Utility

  - by user9154181

  Solaris 11 has a new standard user level command, /usr/bin/elffile. elffile is a variant of the file utility that is focused exclusively on linker related files: ELF objects, archives, and runtime linker configuration files. All other files are simply identified as "non-ELF". The primary advantage of elffile over the existing file utility is in the area of archives — elffile examines the archive members and can produce a summary of the contents, or per-member details. The impetus to add elffile to Solaris came from the effort to extend the format of Solaris archives so that they could grow beyond their previous 32-bit file limits. That work introduced a new archive symbol table format. Now that there was more than one possible format, I thought it would be useful if the file utility could identify which format a given archive is using, leading me to extend the file utility: % cc -c ~/hello.c % ar r foo.a hello.o % file foo.a foo.a: current ar archive, 32-bit symbol table % ar r -S foo.a hello.o % file foo.a foo.a: current ar archive, 64-bit symbol table In turn, this caused me to think about all the things that I would like the file utility to be able to tell me about an archive. In particular, I'd like to be able to know what's inside without having to unpack it. The end result of that train of thought was elffile. Much of the discussion in this article is adapted from the PSARC case I filed for elffile in December 2010: PSARC 2010/432 elffile Why file Is No Good For Archives And Yet Should Not Be Fixed The standard /usr/bin/file utility is not very useful when applied to archives. When identifying an archive, a user typically wants to know 2 things: Is this an archive? Presupposing that the archive contains objects, which is by far the most common use for archives, what platform are the objects for? Are they for sparc or x86? 32 or 64-bit? Some confusing combination from varying platforms? The file utility provides a quick answer to question (1), as it identifies all archives as "current ar archive". It does nothing to answer the more interesting question (2). To answer that question, requires a multi-step process: Extract all archive members Use the file utility on the extracted files, examine the output for each file in turn, and compare the results to generate a suitable summary description. Remove the extracted files It should be easier and more efficient to answer such an obvious question. It would be reasonable to extend the file utility to examine archive contents in place and produce a description. However, there are several reasons why I decided not to do so: The correct design for this feature within the file utility would have file examine each archive member in turn, applying its full abilities to each member. This would be elegant, but also represents a rather dramatic redesign and re-implementation of file. Archives nearly always contain nothing but ELF objects for a single platform, so such generality in the file utility would be of little practical benefit. It is best to avoid adding new options to standard utilities for which other implementations of interest exist. In the case of the file utility, one concern is that we might add an option which later appears in the GNU version of file with a different and incompatible meaning. Indeed, there have been discussions about replacing the Solaris file with the GNU version in the past. This may or may not be desirable, and may or may not ever happen. Either way, I don't want to preclude it. Examining archive members is an O(n) operation, and can be relatively slow with large archives. The file utility is supposed to be a very fast operation. I decided that extending file in this way is overkill, and that an investment in the file utility for better archive support would not be worth the cost. A solution that is more narrowly focused on ELF and other linker related files is really all that we need. The necessary code for doing this already exists within libelf. All that is missing is a small user-level wrapper to make that functionality available at the command line. In that vein, I considered adding an option for this to the elfdump utility. I examined elfdump carefully, and even wrote a prototype implementation. The added code is small and simple, but the conceptual fit with the rest of elfdump is poor. The result complicates elfdump syntax and documentation, definite signs that this functionality does not belong there. And so, I added this functionality as a new user level command. The elffile Command The syntax for this new command is elffile [-s basic | detail | summary] filename... Please see the elffile(1) manpage for additional details. To demonstrate how output from elffile looks, I will use the following files: FileDescription configA runtime linker configuration file produced with crle dwarf.oAn ELF object /etc/passwdA text file mixed.aArchive containing a mixture of ELF and non-ELF members mixed_elf.aArchive containing ELF objects for different machines not_elf.aArchive containing no ELF objects same_elf.aArchive containing a collection of ELF objects for the same machine. This is the most common type of archive. The file utility identifies these files as follows: % file config dwarf.o /etc/passwd mixed.a mixed_elf.a not_elf.a same_elf.a config: Runtime Linking Configuration 64-bit MSB SPARCV9 dwarf.o: ELF 64-bit LSB relocatable AMD64 Version 1 /etc/passwd: ascii text mixed.a: current ar archive, 32-bit symbol table mixed_elf.a: current ar archive, 32-bit symbol table not_elf.a: current ar archive same_elf.a: current ar archive, 32-bit symbol table By default, elffile uses its "summary" output style. This output differs from the output from the file utility in 2 significant ways: Files that are not an ELF object, archive, or runtime linker configuration file are identified as "non-ELF", whereas the file utility attempts further identification for such files. When applied to an archive, the elffile output includes a description of the archive's contents, without requiring member extraction or other additional steps. Applying elffile to the above files: % elffile config dwarf.o /etc/passwd mixed.a mixed_elf.a not_elf.a same_elf.a config: Runtime Linking Configuration 64-bit MSB SPARCV9 dwarf.o: ELF 64-bit LSB relocatable AMD64 Version 1 /etc/passwd: non-ELF mixed.a: current ar archive, 32-bit symbol table, mixed ELF and non-ELF content mixed_elf.a: current ar archive, 32-bit symbol table, mixed ELF content not_elf.a: current ar archive, non-ELF content same_elf.a: current ar archive, 32-bit symbol table, ELF 64-bit LSB relocatable AMD64 Version 1 The output for same_elf.a is of particular interest: The vast majority of archives contain only ELF objects for a single platform, and in this case, the default output from elffile answers both of the questions about archives posed at the beginning of this discussion, in a single efficient step. This makes elffile considerably more useful than file, within the realm of linker-related files. elffile can produce output in two other styles, "basic", and "detail". The basic style produces output that is the same as that from 'file', for linker-related files. The detail style produces per-member identification of archive contents. This can be useful when the archive contents are not homogeneous ELF object, and more information is desired than the summary output provides: % elffile -s detail mixed.a mixed.a: current ar archive, 32-bit symbol table mixed.a(dwarf.o): ELF 32-bit LSB relocatable 80386 Version 1 mixed.a(main.c): non-ELF content mixed.a(main.o): ELF 64-bit LSB relocatable AMD64 Version 1 [SSE]

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• Computer Networks UNISA - Chap 10 &ndash; In Depth TCP/IP Networking

  - by MarkPearl

  After reading this section you should be able to Understand methods of network design unique to TCP/IP networks, including subnetting, CIDR, and address translation Explain the differences between public and private TCP/IP networks Describe protocols used between mail clients and mail servers, including SMTP, POP3, and IMAP4 Employ multiple TCP/IP utilities for network discovery and troubleshooting Designing TCP/IP-Based Networks The following sections explain how network and host information in an IPv4 address can be manipulated to subdivide networks into smaller segments. Subnetting Subnetting separates a network into multiple logically defined segments, or subnets. Networks are commonly subnetted according to geographic locations, departmental boundaries, or technology types. A network administrator might separate traffic to accomplish the following… Enhance security Improve performance Simplify troubleshooting The challenges of Classful Addressing in IPv4 (No subnetting) The simplest type of IPv4 is known as classful addressing (which was the Class A, Class B & Class C network addresses). Classful addressing has the following limitations. Restriction in the number of usable IPv4 addresses (class C would be limited to 254 addresses) Difficult to separate traffic from various parts of a network Because of the above reasons, subnetting was introduced. IPv4 Subnet Masks Subnetting depends on the use of subnet masks to identify how a network is subdivided. A subnet mask indicates where network information is located in an IPv4 address. The 1 in a subnet mask indicates that corresponding bits in the IPv4 address contain network information (likewise 0 indicates the opposite) Each network class is associated with a default subnet mask… Class A = 255.0.0.0 Class B = 255.255.0.0 Class C = 255.255.255.0 An example of calculating  the network ID for a particular device with a subnet mask is shown below.. IP Address = 199.34.89.127 Subnet Mask = 255.255.255.0 Resultant Network ID = 199.34.89.0 IPv4 Subnetting Techniques Subnetting breaks the rules of classful IPv4 addressing. Read page 490 for a detailed explanation Calculating IPv4 Subnets Read page 491 – 494 for an explanation Important… Subnetting only applies to the devices internal to your network. Everything external looks at the class of the IP address instead of the subnet network ID. This way, traffic directed to your network externally still knows where to go, and once it has entered your internal network it can then be prioritized and segmented. CIDR (classless Interdomain Routing) CIDR is also known as classless routing or supernetting. In CIDR conventional network class distinctions do not exist, a subnet boundary can move to the left, therefore generating more usable IP addresses on your network. A subnet created by moving the subnet boundary to the left is known as a supernet. With CIDR also came new shorthand for denoting the position of subnet boundaries known as CIDR notation or slash notation. CIDR notation takes the form of the network ID followed by a forward slash (/) followed by the number of bits that are used for the extended network prefix. To take advantage of classless routing, your networks routers must be able to interpret IP addresses that don;t adhere to conventional network class parameters. Routers that rely on older routing protocols (i.e. RIP) are not capable of interpreting classless IP addresses. Internet Gateways Gateways are a combination of software and hardware that enable two different network segments to exchange data. A gateway facilitates communication between different networks or subnets. Because on device cannot send data directly to a device on another subnet, a gateway must intercede and hand off the information. Every device on a TCP/IP based network has a default gateway (a gateway that first interprets its outbound requests to other subnets, and then interprets its inbound requests from other subnets). The internet contains a vast number of routers and gateways. If each gateway had to track addressing information for every other gateway on the Internet, it would be overtaxed. Instead, each handles only a relatively small amount of addressing information, which it uses to forward data to another gateway that knows more about the data’s destination. The gateways that make up the internet backbone are called core gateways. Address Translation An organizations default gateway can also be used to “hide” the organizations internal IP addresses and keep them from being recognized on a public network. A public network is one that any user may access with little or no restrictions. On private networks, hiding IP addresses allows network managers more flexibility in assigning addresses. Clients behind a gateway may use any IP addressing scheme, regardless of whether it is recognized as legitimate by the Internet authorities but as soon as those devices need to go on the internet, they must have legitimate IP addresses to exchange data. When a clients transmission reaches the default gateway, the gateway opens the IP datagram and replaces the client’s private IP address with an Internet recognized IP address. This process is known as NAT (Network Address Translation). TCP/IP Mail Services All Internet mail services rely on the same principles of mail delivery, storage, and pickup, though they may use different types of software to accomplish these functions. Email servers and clients communicate through special TCP/IP application layer protocols. These protocols, all of which operate on a variety of operating systems are discussed below… SMTP (Simple Mail transfer Protocol) The protocol responsible for moving messages from one mail server to another over TCP/IP based networks. SMTP belongs to the application layer of the ODI model and relies on TCP as its transport protocol. Operates from port 25 on the SMTP server Simple sub-protocol, incapable of doing anything more than transporting mail or holding it in a queue MIME (Multipurpose Internet Mail Extensions) The standard message format specified by SMTP allows for lines that contain no more than 1000 ascii characters meaning if you relied solely on SMTP you would have very short messages and nothing like pictures included in an email. MIME us a standard for encoding and interpreting binary files, images, video, and non-ascii character sets within an email message. MIME identifies each element of a mail message according to content type. MIME does not replace SMTP but works in conjunction with it. Most modern email clients and servers support MIME POP (Post Office Protocol) POP is an application layer protocol used to retrieve messages from a mail server POP3 relies on TCP and operates over port 110 With POP3 mail is delivered and stored on a mail server until it is downloaded by a user Disadvantage of POP3 is that it typically does not allow users to save their messages on the server because of this IMAP is sometimes used IMAP (Internet Message Access Protocol) IMAP is a retrieval protocol that was developed as a more sophisticated alternative to POP3 The single biggest advantage IMAP4 has over POP3 is that users can store messages on the mail server, rather than having to continually download them Users can retrieve all or only a portion of any mail message Users can review their messages and delete them while the messages remain on the server Users can create sophisticated methods of organizing messages on the server Users can share a mailbox in a central location Disadvantages of IMAP are typically related to the fact that it requires more storage space on the server. Additional TCP/IP Utilities Nearly all TCP/IP utilities can be accessed from the command prompt on any type of server or client running TCP/IP. The syntaxt may differ depending on the OS of the client. Below is a list of additional TCP/IP utilities – research their use on your own! Ipconfig (Windows) & Ifconfig (Linux) Netstat Nbtstat Hostname, Host & Nslookup Dig (Linux) Whois (Linux) Traceroute (Tracert) Mtr (my traceroute) Route

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• Simplifying Human Capital Management with Mobile Applications

  - by HCM-Oracle

  By Aaron Green If you're starting to think 'mobility' is a recurring theme in your reading, you'd be right. For those who haven't started to build organisational capabilities to leverage it, it's fair to say you're late to the party. The good news: better late than never. Research firm eMarketer says the worldwide smartphone audience will total 1.75 billion this year, while communications technology and services provider Ericsson suggests smartphones will triple to 5.6 billion globally by 2019. It should be no surprise, smart phone adoption is reaching the farthest corners of the globe; the subsequent impact of enterprise applications enabled by these devices is driving business performance improvement and will continue to do so. Companies using advanced workforce analytics can add significantly to the bottom line, while impacting customer satisfaction, quality and productivity. It's a statement that makes most business leaders sit forward in their chairs. Achieving these three standards is like sipping The Golden Elixir for the business world. No-one would argue their importance. So what are 'advanced workforce analytics?' Simply, they're unprecedented access to workforce trends and performance markers. Many are made possible by a mobile world and the enterprise applications that come with it on smart devices. Some refer to it as 'the consumerisation of IT'. As this phenomenon has matured and become more widely appreciated it has impacted the spectrum of functional units within an enterprise differently, but powerfully. Whether it's sales, HR, marketing, IT, or operations, all have benefited from a more mobile approach. It has been the catalyst for improvement in, and management of, the employee experience. The net result of which is happier customers. The obvious benefits but the lesser realised impact Most people understand that mobility allows for greater efficiency and productivity, collaboration and flexibility, but how that translates into business outcomes within the various functional groups is lesser known. In actuality mobility has helped galvanise partnerships between cross-functional groups within the enterprise. Where in some quarters it was once feared mobility could fragment a workforce, its rallying cry of support is coming from what you might describe as an unlikely source - HR. As the bedrock of an enterprise, it is conceivable HR might contemplate the possible negative impact of a mobile workforce that no-longer sits in an office, at the same desks every day. After all, who would know what they were doing or saying? How would they collaborate? It's reasonable to see why HR might have a legitimate claim to try and retain as much 'perceived control' as possible. The reality however is mobility has emancipated human capital and its management. Mobility and enterprise applications are expediting decision making. Google calls it Zero Moment of Truth, or ZMOT. It enables smoother operation and can contribute to faster growth. From a collaborative perspective, with the growing use of enterprise social media, which in many cases is being driven by HR, workforce planning and the tangible impact of change is much easier to map. This in turn provides a platform from which individuals and teams can thrive. With more agility and ability to anticipate, staff satisfaction and retention is higher, and real time feedback constant. The management team can save time, energy and costs with more accurate data, which is then intelligently applied across the workforce to truly engage with staff, customers and partners. From a human capital management (HCM) perspective, mobility can help you close the loop on true talent management. It can enhance what managers can offer and what employees can provide in return. It can create nested relationships and powerful partnerships. IT and HR - partners and stewards of mobility One effect of enterprise mobility is an evolution in the nature of the relationship between HR and IT from one of service provision to partnership. The reason for the dynamic shift is largely due to the 'bring your own device' (BYOD) movement, which is transitioning to a 'bring your own application' (BYOA) scenario. As enterprise technology has in some ways reverse-engineered its solutions to help manage this situation, the partnership between IT (the functional owner) and HR (the strategic enabler) is deeply entrenched. And it has to be. The CIO and the HR leader are faced with compliance and regulatory issues and concerns around information security and personal privacy on a daily basis, complicated by global reach and varied domestic legislation. There are tens of thousands of new mobile apps entering the market each month and, unlike many consumer applications which get downloaded but are often never opened again after initial perusal, enterprise applications are being relied upon by functional groups, not least by HR to enhance people management. It requires a systematic approach across all applications in use within the enterprise in order to ensure they're used to best effect. No turning back, and no desire to With real time analytics on performance and the ability for immediate feedback, there is no turning back for managers. In my experience with Oracle, our customers' operational efficiency is at record levels. It's clear as a result of the combination of individual KPIs and organisational goals, CIOs have been able to give HR leaders the ability to build predictive models that feed into an enterprise organisations' evolving strategy. It also helps them ensure regulatory compliance much more easily. Once an arduous task, with mobile enabled automation and quality data, compliance is simpler. Their world has changed for the better. For the CIO, mobility also assists them to optimise performance. While it doesn't come without challenges, mobile-enabled applications and the native experience users have with them means employees don't need high-level technical expertise to train users. It reduces the training and engagement required from the IT team so they can focus on other things that deliver value to the bottom line; all the while lowering the cost of assets and related maintenance work by simplifying processes. Rewards of a mobile enterprise outweigh risks With mobile tools allowing us to increasingly integrate our personal and professional lives, terms like "office hours" are becoming irrelevant, so work/life balance is a cultural must. Enterprises are expected to offer tools that enable workers to access information from anywhere, at any time, from any device. Employees want simplicity and convenience but it doesn't stop at private enterprise. This is a societal shift. Governments, which traditionally have been known to be slower to adopt newer technology, are also offering support for local businesses to go mobile. Several state government websites have advice on how to create mobile apps and more. And as recently as last week the Victorian Minister for Technology Gordon Rich-Phillips unveiled his State government's ICT roadmap for the next two years, which details an increased use of the public cloud, as well as mobile communications, and improved access to online data-sets. Tech giants are investing significantly in solutions designed to simplify mobile deployment and enablement. The mobility trend is creating a wave of change in the industry and driving transformation in the enterprise. If you're not on that wave, the business risk continues to rise as your competitiveness drops. Aaron is the Vice President of HCM Strategy at Oracle Corporation where he is responsible for researching and identifying emerging trends in the practice of Human Resources and works to deliver industry-leading technology solutions. Other responsibilities include, ownership of Oracle's innovative HCM solutions across JAPAC and enabling organisations to transform and modernise their workforce tools. Follow him on Twitter @aaronjgreen

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• Delight and Excite

  - by Applications User Experience

  Mick McGee, CEO & President, EchoUser Editor’s Note: EchoUser is a User Experience design firm in San Francisco and a member of the Oracle Usability Advisory Board. Mick and his staff regularly consult on Oracle Applications UX projects. Being part of a user experience design firm, we have the luxury of working with a lot of great people across many great companies. We get to help people solve their problems.  At least we used to. The basic design challenge is still the same; however, the goal is not necessarily to solve “problems” anymore; it is, “I want our products to delight and excite!” The question for us as UX professionals is how to design to those goals, and then how to assess them from a usability perspective. I’m not sure where I first heard “delight and excite” (A book? blog post? Facebook  status? Steve Jobs quote?), but now I hear these listed as user experience goals all the time. In particular, somewhat paradoxically, I routinely hear them in enterprise software conversations. And when asking these same enterprise companies what will make the project successful, we very often hear, “Make it like Apple.” In past days, it was “make it like Yahoo (or Amazon or Google“) but now Apple is the common benchmark. Steve Jobs and Apple were not secrets, but with Jobs’ passing and Apple becoming the world’s most valuable company in the last year, the impact of great design and experience is suddenly very widespread. In particular, users’ expectations have gone way up. Being an enterprise company is no shield to the general expectations that users now have, for all products. Designing a “Minimum Viable Product” The user experience challenge has historically been, to echo the words of Eric Ries (author of Lean Startup) , to create a “minimum viable product”: the proverbial, “make it good enough”. But, in our profession, the “minimum viable” part of that phrase has oftentimes, unfortunately, referred to the design and user experience. Technology typically dominated the focus of the biggest, most successful companies. Few have had the laser focus of Apple to also create and sell design and user experience alongside great technology. But now that Apple is the most valuable company in the world, copying their success is a common undertaking. Great design is now a premium offering that everyone wants, from the one-person startup to the largest companies, consumer and enterprise. This emerging business paradigm will have significant impact across the user experience design process and profession. One area that particularly interests me is, how are we going to evaluate these new emerging “delight and excite” experiences, which are further customized to each particular domain? How to Measure “Delight and Excite” Traditional usability measures of task completion rate, assists, time, and errors are still extremely useful in many situations; however, they are too blunt to offer much insight into emerging experiences “Satisfaction” is usually assessed in user testing, in roughly equivalent importance to the above objective metrics. Various surveys and scales have provided ways to measure satisfying UX, with whatever questions they include. However, to meet the demands of new business goals and keep users at the center of design and development processes, we have to explore new methods to better capture custom-experience goals and emotion-driven user responses. We have had success assessing custom experiences, including “delight and excite”, by employing a variety of user testing methods that tend to combine formative and summative techniques (formative being focused more on identifying usability issues and ways to improve design, and summative focused more on metrics). Our most successful tool has been one we’ve been using for a long time, Magnitude Estimation Technique (MET). But it’s not necessarily about MET as a measure, rather how it is created. Caption: For one client, EchoUser did two rounds of testing.  Each test was a mix of performing representative tasks and gathering qualitative impressions. Each user participated in an in-person moderated 1-on-1 session for 1 hour, using a testing set-up where they held the phone. The primary goal was to identify usability issues and recommend design improvements. MET is based on a definition of the desired experience, which users will then use to rate items of interest (usually tasks in a usability test). In other words, a custom experience definition needs to be created. This can then be used to measure satisfaction in accomplishing tasks; “delight and excite”; or anything else from strategic goals, user demands, or elsewhere. For reference, our standard MET definition in usability testing is: “User experience is your perception of how easy to use, well designed and productive an interface is to complete tasks.” Articulating the User Experience We’ve helped construct experience definitions for several clients to better match their business goals. One example is a modification of the above that was needed for a company that makes medical-related products: “User experience is your perception of how easy to use, well-designed, productive and safe an interface is for conducting tasks. ‘Safe’ is how free an environment (including devices, software, facilities, people, etc.) is from danger, risk, and injury.” Another example is from a company that is pushing hard to incorporate “delight” into their enterprise business line: “User experience is your perception of a product’s ease of use and learning, satisfaction and delight in design, and ability to accomplish objectives.” I find the last one particularly compelling in that there is little that identifies the experience as being for a highly technical enterprise application. That definition could easily be applied to any number of consumer products. We have gone further than the above, including “sexy” and “cool” where decision-makers insisted they were part of the desired experience. We also applied it to completely different experiences where the “interface” was, for example, riding public transit, the “tasks” were train rides, and we followed the participants through the train-riding journey and rated various aspects accordingly: “A good public transportation experience is a cost-effective way of reliably, conveniently, and safely getting me to my intended destination on time.” To construct these definitions, we’ve employed both bottom-up and top-down approaches, depending on circumstances. For bottom-up, user inputs help dictate the terms that best fit the desired experience (usually by way of cluster and factor analysis). Top-down depends on strategic, visionary goals expressed by upper management that we then attempt to integrate into product development (e.g., “delight and excite”). We like a combination of both approaches to push the innovation envelope, but still be mindful of current user concerns. Hopefully the idea of crafting your own custom experience, and a way to measure it, can provide you with some ideas how you can adapt your user experience needs to whatever company you are in. Whether product-development or service-oriented, nearly every company is ultimately providing a user experience. The Bottom Line Creating great experiences may have been popularized by Steve Jobs and Apple, but I’ll be honest, it’s a good feeling to be moving from “good enough” to “delight and excite,” despite the challenge that entails. In fact, it’s because of that challenge that we will expand what we do as UX professionals to help deliver and assess those experiences. I’m excited to see how we, Oracle, and the rest of the industry will live up to that challenge.

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• Oracle HRMS API – Update Employee Assignment

  - by PRajkumar

  To Update Supervisor, Manager Flag, Bargaining Unit, Labour Union Member Flag, Gre, Time Card, Work Schedule, Normal Hours, Frequency, Time Normal Finish, Time Normal Start, Default Code Combination, Set of Books Id API -- hr_assignment_api.update_emp_asg   To Update Grade, Location, Job, Payroll, Organization, Employee Category, People Group API -- hr_assignment_api.update_emp_asg_criteria   Example --   DECLARE    -- Local Variables    -- -----------------------    lc_dt_ud_mode           VARCHAR2(100)    := NULL;    ln_assignment_id       NUMBER                  := 33561;    ln_supervisor_id        NUMBER                  := 2;    ln_object_number       NUMBER                  := 1;    ln_people_group_id  NUMBER                  := 1;      -- Out Variables for Find Date Track Mode API    -- -----------------------------------------------------------------    lb_correction                           BOOLEAN;    lb_update                                 BOOLEAN;    lb_update_override              BOOLEAN;    lb_update_change_insert   BOOLEAN;       -- Out Variables for Update Employee Assignment API    -- ----------------------------------------------------------------------------    ln_soft_coding_keyflex_id       HR_SOFT_CODING_KEYFLEX.SOFT_CODING_KEYFLEX_ID%TYPE;    lc_concatenated_segments       VARCHAR2(2000);    ln_comment_id                             PER_ALL_ASSIGNMENTS_F.COMMENT_ID%TYPE;    lb_no_managers_warning        BOOLEAN;  -- Out Variables for Update Employee Assgment Criteria  -- -------------------------------------------------------------------------------  ln_special_ceiling_step_id                    PER_ALL_ASSIGNMENTS_F.SPECIAL_CEILING_STEP_ID%TYPE;  lc_group_name                                          VARCHAR2(30);  ld_effective_start_date                             PER_ALL_ASSIGNMENTS_F.EFFECTIVE_START_DATE%TYPE;  ld_effective_end_date                              PER_ALL_ASSIGNMENTS_F.EFFECTIVE_END_DATE%TYPE;  lb_org_now_no_manager_warning   BOOLEAN;  lb_other_manager_warning                  BOOLEAN;  lb_spp_delete_warning                          BOOLEAN;  lc_entries_changed_warning                VARCHAR2(30);  lb_tax_district_changed_warn             BOOLEAN;   BEGIN    -- Find Date Track Mode    -- --------------------------------    dt_api.find_dt_upd_modes    (    p_effective_date                  => TO_DATE('12-JUN-2011'),         p_base_table_name            => 'PER_ALL_ASSIGNMENTS_F',         p_base_key_column           => 'ASSIGNMENT_ID',         p_base_key_value               => ln_assignment_id,          -- Output data elements          -- --------------------------------          p_correction                          => lb_correction,          p_update                                => lb_update,          p_update_override              => lb_update_override,          p_update_change_insert   => lb_update_change_insert      );      IF ( lb_update_override = TRUE OR lb_update_change_insert = TRUE )    THEN        -- UPDATE_OVERRIDE        -- ---------------------------------        lc_dt_ud_mode := 'UPDATE_OVERRIDE';    END IF;     IF ( lb_correction = TRUE )   THEN       -- CORRECTION       -- ----------------------      lc_dt_ud_mode := 'CORRECTION';   END IF;     IF ( lb_update = TRUE )   THEN       -- UPDATE       -- --------------       lc_dt_ud_mode := 'UPDATE';    END IF;     -- Update Employee Assignment   -- ---------------------------------------------  hr_assignment_api.update_emp_asg  ( -- Input data elements   -- ------------------------------   p_effective_date                              => TO_DATE('12-JUN-2011'),   p_datetrack_update_mode         => lc_dt_ud_mode,   p_assignment_id                            => ln_assignment_id,   p_supervisor_id                              => NULL,   p_change_reason                           => NULL,   p_manager_flag                              => 'N',   p_bargaining_unit_code              => NULL,   p_labour_union_member_flag   => NULL,   p_segment1                                       => 204,   p_segment3                                       => 'N',   p_normal_hours                              => 10,   p_frequency                                       => 'W',   -- Output data elements   -- -------------------------------   p_object_version_number             => ln_object_number,   p_soft_coding_keyflex_id              => ln_soft_coding_keyflex_id,   p_concatenated_segments             => lc_concatenated_segments,   p_comment_id                                   => ln_comment_id,   p_effective_start_date                      => ld_effective_start_date,   p_effective_end_date                        => ld_effective_end_date,   p_no_managers_warning               => lb_no_managers_warning,   p_other_manager_warning            => lb_other_manager_warning  );    -- Find Date Track Mode for Second API   -- ------------------------------------------------------   dt_api.find_dt_upd_modes   (  p_effective_date                   => TO_DATE('12-JUN-2011'),      p_base_table_name            => 'PER_ALL_ASSIGNMENTS_F',      p_base_key_column           => 'ASSIGNMENT_ID',      p_base_key_value               => ln_assignment_id,      -- Output data elements      -- -------------------------------      p_correction                           => lb_correction,      p_update                                 => lb_update,      p_update_override               => lb_update_override,      p_update_change_insert    => lb_update_change_insert   );     IF ( lb_update_override = TRUE OR lb_update_change_insert = TRUE )   THEN     -- UPDATE_OVERRIDE     -- --------------------------------     lc_dt_ud_mode := 'UPDATE_OVERRIDE';   END IF;      IF ( lb_correction = TRUE )    THEN      -- CORRECTION      -- ----------------------      lc_dt_ud_mode := 'CORRECTION';   END IF;      IF ( lb_update = TRUE )    THEN      -- UPDATE      -- --------------      lc_dt_ud_mode := 'UPDATE';    END IF;    -- Update Employee Assgment Criteria  -- -----------------------------------------------------  hr_assignment_api.update_emp_asg_criteria  ( -- Input data elements   -- ------------------------------   p_effective_date                                   => TO_DATE('12-JUN-2011'),   p_datetrack_update_mode               => lc_dt_ud_mode,   p_assignment_id                                 => ln_assignment_id,   p_location_id                                        => 204,   p_grade_id                                             => 29,   p_job_id                                                  => 16,   p_payroll_id                                          => 52,   p_organization_id                               => 239,   p_employment_category                    => 'FR',   -- Output data elements   -- -------------------------------   p_people_group_id                              => ln_people_group_id,   p_object_version_number                   => ln_object_number,   p_special_ceiling_step_id                  => ln_special_ceiling_step_id,   p_group_name                                        => lc_group_name,   p_effective_start_date                           => ld_effective_start_date,   p_effective_end_date                             => ld_effective_end_date,   p_org_now_no_manager_warning  => lb_org_now_no_manager_warning,   p_other_manager_warning                 => lb_other_manager_warning,   p_spp_delete_warning                         => lb_spp_delete_warning,   p_entries_changed_warning              => lc_entries_changed_warning,   p_tax_district_changed_warning     => lb_tax_district_changed_warn  );    COMMIT; EXCEPTION          WHEN OTHERS THEN                       ROLLBACK;                       dbms_output.put_line(SQLERRM); END; / SHOW ERR;    

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• Controlling the Sizing of the af:messages Dialog

  - by Duncan Mills

  Over the last day or so a small change in behaviour between 11.1.2.n releases of ADF and earlier versions has come to my attention. This has concerned the default sizing of the dialog that the framework automatically generates to handle the display of JSF messages being handled by the <af:messages> component. Unlike a normal popup, you don't have a physical <af:dialog> or <af:window> to set the sizing on in your page definition, so you're at the mercy of what the framework provides. In this case the framework now defines a fixed 250x250 pixel content area dialog for these messages, which can look a bit weird if the message is either very short, or very long. Unfortunately this is not something that you can control through the skin, instead you have to be a little more creative. Here's the solution I've come up with.  Unfortunately, I've not found a supportable way to reset the dialog so as to say  just size yourself based on your contents, it is actually possible to do this by tweaking the correct DOM objects, but I wanted to start with a mostly supportable solution that only uses the best practice of working through the ADF client side APIs. The Technique The basic approach I've taken is really very simple.  The af:messages dialog is just a normal richDialog object, it just happens to be one that is pre-defined for you with a particular known name "msgDlg" (which hopefully won't change). Knowing this, you can call the accepted APIs to control the content width and height of that dialog, as our meerkat friends would say, "simples" 1 The JavaScript For this example I've defined three JavaScript functions.   The first does all the hard work and is designed to be called from server side Java or from a page load event to set the default. The second is a utility function used by the first to validate the values you're about to use for height and width. The final function is one that can be called from the page load event to set an initial default sizing if that's all you need to do. Function resizeDefaultMessageDialog() /**  * Function that actually resets the default message dialog sizing.  * Note that the width and height supplied define the content area  * So the actual physical dialog size will be larger to account for  * the chrome containing the header / footer etc.  * @param docId Faces component id of the document  * @param contentWidth - new content width you need  * @param contentHeight - new content height  */ function resizeDefaultMessageDialog(docId, contentWidth, contentHeight) {   // Warning this value may change from release to release   var defMDName = "::msgDlg";   //Find the default messages dialog   msgDialogComponent = AdfPage.PAGE.findComponentByAbsoluteId(docId + defMDName); // In your version add a check here to ensure we've found the right object!   // Check the new width is supplied and is a positive number, if so apply it.   if (dimensionIsValid(contentWidth)){       msgDialogComponent.setContentWidth(contentWidth);   }   // Check the new height is supplied and is a positive number, if so apply it.   if (dimensionIsValid(contentHeight)){       msgDialogComponent.setContentHeight(contentHeight);   } }  Function dimensionIsValid()  /**  * Simple function to check that sensible numeric values are   * being proposed for a dimension  * @param sampleDimension   * @return booolean  */ function dimensionIsValid(sampleDimension){     return (!isNaN(sampleDimension) && sampleDimension > 0); } Function  initializeDefaultMessageDialogSize() /**  * This function will re-define the default sizing applied by the framework   * in 11.1.2.n versions  * It is designed to be called with the document onLoad event  */ function initializeDefaultMessageDialogSize(loadEvent){   //get the configuration information   var documentId = loadEvent.getSource().getProperty('documentId');   var newWidth = loadEvent.getSource().getProperty('defaultMessageDialogContentWidth');   var newHeight = loadEvent.getSource().getProperty('defaultMessageDialogContentHeight');   resizeDefaultMessageDialog(documentId, newWidth, newHeight); } Wiring in the Functions As usual, the first thing we need to do when using JavaScript with ADF is to define an af:resource  in the document metaContainer facet <af:document>   ....     <f:facet name="metaContainer">     <af:resource type="javascript" source="/resources/js/hackMessagedDialog.js"/>    </f:facet> </af:document> This makes the script functions available to call.  Next if you want to use the option of defining an initial default size for the dialog you use a combination of <af:clientListener> and <af:clientAttribute> tags like this. <af:document title="MyApp" id="doc1">   <af:clientListener method="initializeDefaultMessageDialogSize" type="load"/>   <af:clientAttribute name="documentId" value="doc1"/>   <af:clientAttribute name="defaultMessageDialogContentWidth" value="400"/>   <af:clientAttribute name="defaultMessageDialogContentHeight" value="150"/>  ...   Just in Time Dialog Sizing  So  what happens if you have a variety of messages that you might add and in some cases you need a small dialog and an other cases a large one? Well in that case you can re-size these dialogs just before you submit the message. Here's some example Java code: FacesContext ctx = FacesContext.getCurrentInstance();          //reset the default dialog size for this message ExtendedRenderKitService service =              Service.getRenderKitService(ctx, ExtendedRenderKitService.class); service.addScript(ctx, "resizeDefaultMessageDialog('doc1',100,50);");          FacesMessage msg = new FacesMessage("Short message"); msg.setSeverity(FacesMessage.SEVERITY_ERROR); ctx.addMessage(null, msg);  So there you have it. This technique should, at least, allow you to control the dialog sizing just enough to stop really objectionable whitespace or scrollbars. 1 Don't worry if you don't get the reference, lest's just say my kids watch too many adverts.

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• FreeBSD performance tuning. Sysctls, loader.conf, kernel

  - by SaveTheRbtz

  I wanted to share knowledge of tuning FreeBSD via sysctl.conf/loader.conf/KENCONF. It was initially based on Igor Sysoev's (author of nginx) presentation about FreeBSD tuning up to 100,000-200,000 active connections. Tunings are for FreeBSD-CURRENT. Since 7.2 amd64 some of them are tuned well by default. Prior 7.0 some of them are boot only (set via /boot/loader.conf) or does not exist at all. sysctl.conf: # No zero mapping feature # May break wine # (There are also reports about broken samba3) #security.bsd.map_at_zero=0 # If you have really busy webserver with apache13 you may run out of processes #kern.maxproc=10000 # Same for servers with apache2 / Pound #kern.threads.max_threads_per_proc=4096 # Max. backlog size kern.ipc.somaxconn=4096 # Shared memory // 7.2+ can use shared memory > 2Gb kern.ipc.shmmax=2147483648 # Sockets kern.ipc.maxsockets=204800 # Can cause this on older kernels: # http://old.nabble.com/Significant-performance-regression-for-increased-maxsockbuf-on-8.0-RELEASE-tt26745981.html#a26745981 ) kern.ipc.maxsockbuf=10485760 # Mbuf 2k clusters (on amd64 7.2+ 25600 is default) # For such high value vm.kmem_size must be increased to 3G kern.ipc.nmbclusters=262144 # Jumbo pagesize(_SC_PAGESIZE) clusters # Used as general packet storage for jumbo frames # can be monitored via `netstat -m` #kern.ipc.nmbjumbop=262144 # Jumbo 9k/16k clusters # If you are using them #kern.ipc.nmbjumbo9=65536 #kern.ipc.nmbjumbo16=32768 # For lower latency you can decrease scheduler's maximum time slice # default: stathz/10 (~ 13) #kern.sched.slice=1 # Increase max command-line length showed in `ps` (e.g for Tomcat/Java) # Default is PAGE_SIZE / 16 or 256 on x86 # This avoids commands to be presented as [executable] in `ps` # For more info see: http://www.freebsd.org/cgi/query-pr.cgi?pr=120749 kern.ps_arg_cache_limit=4096 # Every socket is a file, so increase them kern.maxfiles=204800 kern.maxfilesperproc=200000 kern.maxvnodes=200000 # On some systems HPET is almost 2 times faster than default ACPI-fast # Useful on systems with lots of clock_gettime / gettimeofday calls # See http://old.nabble.com/ACPI-fast-default-timecounter,-but-HPET-83--faster-td23248172.html # After revision 222222 HPET became default: http://svnweb.freebsd.org/base?view=revision&revision=222222 kern.timecounter.hardware=HPET # Small receive space, only usable on http-server, on file server this # should be increased to 65535 or even more #net.inet.tcp.recvspace=8192 # This is useful on Fat-Long-Pipes #net.inet.tcp.recvbuf_max=10485760 #net.inet.tcp.recvbuf_inc=65535 # Small send space is useful for http servers that serve small files # Autotuned since 7.x net.inet.tcp.sendspace=16384 # This is useful on Fat-Long-Pipes #net.inet.tcp.sendbuf_max=10485760 #net.inet.tcp.sendbuf_inc=65535 # Turn off receive autotuning # You can play with it. #net.inet.tcp.recvbuf_auto=0 #net.inet.tcp.sendbuf_auto=0 # This should be enabled if you going to use big spaces (>64k) # Also timestamp field is useful when using syncookies net.inet.tcp.rfc1323=1 # Turn this off on high-speed, lossless connections (LAN 1Gbit+) # If you set it there is no need in TCP_NODELAY sockopt (see man tcp) net.inet.tcp.delayed_ack=0 # This feature is useful if you are serving data over modems, Gigabit Ethernet, # or even high speed WAN links (or any other link with a high bandwidth delay product), # especially if you are also using window scaling or have configured a large send window. # Automatically disables on small RTT ( http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet/tcp_subr.c?#rev1.237 ) # This sysctl was removed in 10-CURRENT: # See: http://www.mail-archive.com/[email protected]/msg06178.html #net.inet.tcp.inflight.enable=0 # TCP slowstart algorithm tunings # We assuming we have very fast clients #net.inet.tcp.slowstart_flightsize=100 #net.inet.tcp.local_slowstart_flightsize=100 # Disable randomizing of ports to avoid false RST # Before usage check SA here www.bsdcan.org/2006/papers/ImprovingTCPIP.pdf # (it's also says that port randomization auto-disables at some conn.rates, but I didn't checked it thou) #net.inet.ip.portrange.randomized=0 # Increase portrange # For outgoing connections only. Good for seed-boxes and ftp servers. net.inet.ip.portrange.first=1024 net.inet.ip.portrange.last=65535 # # stops route cache degregation during a high-bandwidth flood # http://www.freebsd.org/doc/en/books/handbook/securing-freebsd.html #net.inet.ip.rtexpire=2 net.inet.ip.rtminexpire=2 net.inet.ip.rtmaxcache=1024 # Security net.inet.ip.redirect=0 net.inet.ip.sourceroute=0 net.inet.ip.accept_sourceroute=0 net.inet.icmp.maskrepl=0 net.inet.icmp.log_redirect=0 net.inet.icmp.drop_redirect=1 net.inet.tcp.drop_synfin=1 # # There is also good example of sysctl.conf with comments: # http://www.thern.org/projects/sysctl.conf # # icmp may NOT rst, helpful for those pesky spoofed # icmp/udp floods that end up taking up your outgoing # bandwidth/ifqueue due to all that outgoing RST traffic. # #net.inet.tcp.icmp_may_rst=0 # Security net.inet.udp.blackhole=1 net.inet.tcp.blackhole=2 # IPv6 Security # For more info see http://www.fosslc.org/drupal/content/security-implications-ipv6 # Disable Node info replies # To see this vulnerability in action run `ping6 -a sglAac ::1` or `ping6 -w ::1` on unprotected node net.inet6.icmp6.nodeinfo=0 # Turn on IPv6 privacy extensions # For more info see proposal http://unix.derkeiler.com/Mailing-Lists/FreeBSD/net/2008-06/msg00103.html net.inet6.ip6.use_tempaddr=1 net.inet6.ip6.prefer_tempaddr=1 # Disable ICMP redirect net.inet6.icmp6.rediraccept=0 # Disable acceptation of RA and auto linklocal generation if you don't use them #net.inet6.ip6.accept_rtadv=0 #net.inet6.ip6.auto_linklocal=0 # Increases default TTL, sometimes useful # Default is 64 net.inet.ip.ttl=128 # Lessen max segment life to conserve resources # ACK waiting time in miliseconds # (default: 30000. RFC from 1979 recommends 120000) net.inet.tcp.msl=5000 # Max bumber of timewait sockets net.inet.tcp.maxtcptw=200000 # Don't use tw on local connections # As of 15 Apr 2009. Igor Sysoev says that nolocaltimewait has some buggy realization. # So disable it or now till get fixed #net.inet.tcp.nolocaltimewait=1 # FIN_WAIT_2 state fast recycle net.inet.tcp.fast_finwait2_recycle=1 # Time before tcp keepalive probe is sent # default is 2 hours (7200000) #net.inet.tcp.keepidle=60000 # Should be increased until net.inet.ip.intr_queue_drops is zero net.inet.ip.intr_queue_maxlen=4096 # Interrupt handling via multiple CPU, but with context switch. # You can play with it. Default is 1; #net.isr.direct=0 # This is for routers only #net.inet.ip.forwarding=1 #net.inet.ip.fastforwarding=1 # This speed ups dummynet when channel isn't saturated net.inet.ip.dummynet.io_fast=1 # Increase dummynet(4) hash #net.inet.ip.dummynet.hash_size=2048 #net.inet.ip.dummynet.max_chain_len # Should be increased when you have A LOT of files on server # (Increase until vfs.ufs.dirhash_mem becomes lower) vfs.ufs.dirhash_maxmem=67108864 # Note from commit http://svn.freebsd.org/base/head@211031 : # For systems with RAID volumes and/or virtualization envirnments, where # read performance is very important, increasing this sysctl tunable to 32 # or even more will demonstratively yield additional performance benefits. vfs.read_max=32 # Explicit Congestion Notification (see http://en.wikipedia.org/wiki/Explicit_Congestion_Notification) net.inet.tcp.ecn.enable=1 # Flowtable - flow caching mechanism # Useful for routers #net.inet.flowtable.enable=1 #net.inet.flowtable.nmbflows=65535 # Extreme polling tuning #kern.polling.burst_max=1000 #kern.polling.each_burst=1000 #kern.polling.reg_frac=100 #kern.polling.user_frac=1 #kern.polling.idle_poll=0 # IPFW dynamic rules and timeouts tuning # Increase dyn_buckets till net.inet.ip.fw.curr_dyn_buckets is lower net.inet.ip.fw.dyn_buckets=65536 net.inet.ip.fw.dyn_max=65536 net.inet.ip.fw.dyn_ack_lifetime=120 net.inet.ip.fw.dyn_syn_lifetime=10 net.inet.ip.fw.dyn_fin_lifetime=2 net.inet.ip.fw.dyn_short_lifetime=10 # Make packets pass firewall only once when using dummynet # i.e. packets going thru pipe are passing out from firewall with accept #net.inet.ip.fw.one_pass=1 # shm_use_phys Wires all shared pages, making them unswappable # Use this to lessen Virtual Memory Manager's work when using Shared Mem. # Useful for databases #kern.ipc.shm_use_phys=1 # ZFS # Enable prefetch. Useful for sequential load type i.e fileserver. # FreeBSD sets vfs.zfs.prefetch_disable to 1 on any i386 systems and # on any amd64 systems with less than 4GB of avaiable memory # For additional info check this nabble thread http://old.nabble.com/Samba-read-speed-performance-tuning-td27964534.html #vfs.zfs.prefetch_disable=0 # On highload servers you may notice following message in dmesg: # "Approaching the limit on PV entries, consider increasing either the # vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable" vm.pmap.shpgperproc=2048 loader.conf: # Accept filters for data, http and DNS requests # Useful when your software uses select() instead of kevent/kqueue or when you under DDoS # DNS accf available on 8.0+ accf_data_load="YES" accf_http_load="YES" accf_dns_load="YES" # Async IO system calls aio_load="YES" # Linux specific devices in /dev # As for 8.1 it only /dev/full #lindev_load="YES" # Adds NCQ support in FreeBSD # WARNING! all ad[0-9]+ devices will be renamed to ada[0-9]+ # 8.0+ only #ahci_load="YES" #siis_load="YES" # FreeBSD 8.2+ # New Congestion Control for FreeBSD # http://caia.swin.edu.au/urp/newtcp/tools/cc_chd-readme-0.1.txt # http://www.ietf.org/proceedings/78/slides/iccrg-5.pdf # Initial merge commit message http://www.mail-archive.com/[email protected]/msg31410.html #cc_chd_load="YES" # Increase kernel memory size to 3G. # # Use ONLY if you have KVA_PAGES in kernel configuration, and you have more than 3G RAM # Otherwise panic will happen on next reboot! # # It's required for high buffer sizes: kern.ipc.nmbjumbop, kern.ipc.nmbclusters, etc # Useful on highload stateful firewalls, proxies or ZFS fileservers # (FreeBSD 7.2+ amd64 users: Check that current value is lower!) #vm.kmem_size="3G" # If your server has lots of swap (>4Gb) you should increase following value # according to http://lists.freebsd.org/pipermail/freebsd-hackers/2009-October/029616.html # Otherwise you'll be getting errors # "kernel: swap zone exhausted, increase kern.maxswzone" # kern.maxswzone="256M" # Older versions of FreeBSD can't tune maxfiles on the fly #kern.maxfiles="200000" # Useful for databases # Sets maximum data size to 1G # (FreeBSD 7.2+ amd64 users: Check that current value is lower!) #kern.maxdsiz="1G" # Maximum buffer size(vfs.maxbufspace) # You can check current one via vfs.bufspace # Should be lowered/upped depending on server's load-type # Usually decreased to preserve kmem # (default is 10% of mem) #kern.maxbcache="512M" # Sendfile buffers # For i386 only #kern.ipc.nsfbufs=10240 # FreeBSD 9+ # HPET "legacy route" support. It should allow HPET to work per-CPU # See http://www.mail-archive.com/[email protected]/msg03603.html #hint.atrtc.0.clock=0 #hint.attimer.0.clock=0 #hint.hpet.0.legacy_route=1 # syncache Hash table tuning net.inet.tcp.syncache.hashsize=1024 net.inet.tcp.syncache.bucketlimit=512 net.inet.tcp.syncache.cachelimit=65536 # Increased hostcache # Later host cache can be viewed via net.inet.tcp.hostcache.list hidden sysctl # Very useful for it's RTT RTTVAR # Must be power of two net.inet.tcp.hostcache.hashsize=65536 # hashsize * bucketlimit (which is 30 by default) # It allocates 255Mb (1966080*136) of RAM net.inet.tcp.hostcache.cachelimit=1966080 # TCP control-block Hash table tuning net.inet.tcp.tcbhashsize=4096 # Disable ipfw deny all # Should be uncommented when there is a chance that # kernel and ipfw binary may be out-of sync on next reboot #net.inet.ip.fw.default_to_accept=1 # # SIFTR (Statistical Information For TCP Research) is a kernel module that # logs a range of statistics on active TCP connections to a log file. # See prerelease notes http://groups.google.com/group/mailing.freebsd.current/browse_thread/thread/b4c18be6cdce76e4 # and man 4 sitfr #siftr_load="YES" # Enable superpages, for 7.2+ only # Also read http://lists.freebsd.org/pipermail/freebsd-hackers/2009-November/030094.html vm.pmap.pg_ps_enabled=1 # Usefull if you are using Intel-Gigabit NIC #hw.em.rxd=4096 #hw.em.txd=4096 #hw.em.rx_process_limit="-1" # Also if you have ALOT interrupts on NIC - play with following parameters # NOTE: You should set them for every NIC #dev.em.0.rx_int_delay: 250 #dev.em.0.tx_int_delay: 250 #dev.em.0.rx_abs_int_delay: 250 #dev.em.0.tx_abs_int_delay: 250 # There is also multithreaded version of em/igb drivers can be found here: # http://people.yandex-team.ru/~wawa/ # # for additional em monitoring and statistics use # sysctl dev.em.0.stats=1 ; dmesg # sysctl dev.em.0.debug=1 ; dmesg # Also after r209242 (-CURRENT) there is a separate sysctl for each stat variable; # Same tunings for igb #hw.igb.rxd=4096 #hw.igb.txd=4096 #hw.igb.rx_process_limit=100 # Some useful netisr tunables. See sysctl net.isr #net.isr.maxthreads=4 #net.isr.defaultqlimit=4096 #net.isr.maxqlimit: 10240 # Bind netisr threads to CPUs #net.isr.bindthreads=1 # # FreeBSD 9.x+ # Increase interface send queue length # See commit message http://svn.freebsd.org/viewvc/base?view=revision&revision=207554 #net.link.ifqmaxlen=1024 # Nicer boot logo =) loader_logo="beastie" And finally here is KERNCONF: # Just some of them, see also # cat /sys/{i386,amd64,}/conf/NOTES # This one useful only on i386 #options KVA_PAGES=512 # You can play with HZ in environments with high interrupt rate (default is 1000) # 100 is for my notebook to prolong it's battery life #options HZ=100 # Polling is goot on network loads with high packet rates and low-end NICs # NB! Do not enable it if you want more than one netisr thread #options DEVICE_POLLING # Eliminate datacopy on socket read-write # To take advantage with zero copy sockets you should have an MTU >= 4k # This req. is only for receiving data. # Read more in man zero_copy_sockets # Also this epic thread on kernel trap: # http://kerneltrap.org/node/6506 # Here Linus says that "anybody that does it that way (FreeBSD) is totally incompetent" #options ZERO_COPY_SOCKETS # Support TCP sign. Used for IPSec options TCP_SIGNATURE # There was stackoverflow found in KAME IPSec stack: # See http://secunia.com/advisories/43995/ # For quick workaround you can use `ipfw add deny proto ipcomp` options IPSEC # This ones can be loaded as modules. They described in loader.conf section #options ACCEPT_FILTER_DATA #options ACCEPT_FILTER_HTTP # Adding ipfw, also can be loaded as modules options IPFIREWALL # On 8.1+ you can disable verbose to see blocked packets on ipfw0 interface. # Also there is no point in compiling verbose into the kernel, because # now there is net.inet.ip.fw.verbose tunable. #options IPFIREWALL_VERBOSE #options IPFIREWALL_VERBOSE_LIMIT=10 options IPFIREWALL_FORWARD # Adding kernel NAT options IPFIREWALL_NAT options LIBALIAS # Traffic shaping options DUMMYNET # Divert, i.e. for userspace NAT options IPDIVERT # This is for OpenBSD's pf firewall device pf device pflog # pf's QoS - ALTQ options ALTQ options ALTQ_CBQ # Class Bases Queuing (CBQ) options ALTQ_RED # Random Early Detection (RED) options ALTQ_RIO # RED In/Out options ALTQ_HFSC # Hierarchical Packet Scheduler (HFSC) options ALTQ_PRIQ # Priority Queuing (PRIQ) options ALTQ_NOPCC # Required for SMP build # Pretty console # Manual can be found here http://forums.freebsd.org/showthread.php?t=6134 #options VESA #options SC_PIXEL_MODE # Disable reboot on Ctrl Alt Del #options SC_DISABLE_REBOOT # Change normal|kernel messages color options SC_NORM_ATTR=(FG_GREEN|BG_BLACK) options SC_KERNEL_CONS_ATTR=(FG_YELLOW|BG_BLACK) # More scroll space options SC_HISTORY_SIZE=8192 # Adding hardware crypto device device crypto device cryptodev # Useful network interfaces device vlan device tap #Virtual Ethernet driver device gre #IP over IP tunneling device if_bridge #Bridge interface device pfsync #synchronization interface for PF device carp #Common Address Redundancy Protocol device enc #IPsec interface device lagg #Link aggregation interface device stf #IPv4-IPv6 port # Also for my notebook, but may be used with Opteron device amdtemp # Same for Intel processors device coretemp # man 4 cpuctl device cpuctl # CPU control pseudo-device # Support for ECMP. More than one route for destination # Works even with default route so one can use it as LB for two ISP # For now code is unstable and panics (panic: rtfree 2) on route deletions. #options RADIX_MPATH # Multicast routing #options MROUTING #options PIM # Debug & DTrace options KDB # Kernel debugger related code options KDB_TRACE # Print a stack trace for a panic options KDTRACE_FRAME # amd64-only(?) options KDTRACE_HOOKS # all architectures - enable general DTrace hooks #options DDB #options DDB_CTF # all architectures - kernel ELF linker loads CTF data # Adaptive spining in lockmgr (8.x+) # See http://www.mail-archive.com/[email protected]/msg10782.html options ADAPTIVE_LOCKMGRS # UTF-8 in console (8.x+) #options TEKEN_UTF8 # FreeBSD 8.1+ # Deadlock resolver thread # For additional information see http://www.mail-archive.com/[email protected]/msg18124.html # (FYI: "resolution" is panic so use with caution) #options DEADLKRES # Increase maximum size of Raw I/O and sendfile(2) readahead #options MAXPHYS=(1024*1024) #options MAXBSIZE=(1024*1024) # For scheduler debug enable following option. # Debug will be available via `kern.sched.stats` sysctl # For more information see http://svnweb.freebsd.org/base/head/sys/conf/NOTES?view=markup #options SCHED_STATS If you are tuning network for maximum performance you may wish to play with ifconfig options like: # You can list all capabilities via `ifconfig -m` ifconfig [-]rxcsum [-]txcsum [-]tso [-]lro mtu In case you've enabled DDB in kernel config, you should edit your /etc/ddb.conf and add something like this to enable automatic reboot (and textdump as bonus): script kdb.enter.panic=textdump set; capture on; show pcpu; bt; ps; alltrace; capture off; call doadump; reset script kdb.enter.default=textdump set; capture on; bt; ps; capture off; call doadump; reset And do not forget to add ddb_enable="YES" to /etc/rc.conf Since FreeBSD 9 you can select to enable/disable flowcontrol on your NIC: # See http://en.wikipedia.org/wiki/Ethernet_flow_control and # http://www.mail-archive.com/[email protected]/msg07927.html for additional info ifconfig bge0 media auto mediaopt flowcontrol PS. Also most of FreeBSD's limits can be monitored by # vmstat -z and # limits PPS. variety of network counters can be monitored via # netstat -s In FreeBSD-9 netstat's -Q option appeared, try following command to display netisr stats # netstat -Q PPPS. also see # man 7 tuning PPPPS. I wanted to thank FreeBSD community, especially author of nginx - Igor Sysoev, nginx-ru@ and FreeBSD-performance@ mailing lists for providing useful information about FreeBSD tuning. FreeBSD WIP * Whats cooking for FreeBSD 7? * Whats cooking for FreeBSD 8? * Whats cooking for FreeBSD 9? So here is the question: What tunings are you using on yours FreeBSD servers? You can also post your /etc/sysctl.conf, /boot/loader.conf, kernel options, etc with description of its' meaning (do not copy-paste from sysctl -d). Don't forget to specify server type (web, smb, gateway, etc) Let's share experience!

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• Kernel oops on Linux running in VirtualBox breaks some IO-related functionality on the server

  - by Kristoffer E

  We are having problems with CentOS release 6.3 running in VirtualBox on Windows 7 machines. The symptoms are the following: Everything works as normal for several hours, even days. Then something happens which breaks the system. What we still can do after this something happens: Access the web server Use existing SSH sessions to run top and free What does not work: Starting new SSH sessions (hangs after username and password is entered) Running ls in existing SSH sessions (hangs) SSI includes from our web servers that fetch data from remote machines probably more What we see on the server when this something happens is the following: Load average go from basically nothing to around 3 CPU usage is still low (5%) Disk activity is low (running iostat) Plenty of memory available Plenty of disk space available In /var/log/messages we get the following: Jun 14 01:10:48 devvm kernel: e1000 0000:00:03.0: eth0: Detected Tx Unit Hang Jun 14 01:10:48 devvm kernel: Tx Queue <0> Jun 14 01:10:48 devvm kernel: TDH <2e> Jun 14 01:10:48 devvm kernel: TDT <30> Jun 14 01:10:48 devvm kernel: next_to_use <30> Jun 14 01:10:48 devvm kernel: next_to_clean <2e> Jun 14 01:10:48 devvm kernel: buffer_info[next_to_clean] Jun 14 01:10:48 devvm kernel: time_stamp <1038284db> Jun 14 01:10:48 devvm kernel: next_to_watch <2f> Jun 14 01:10:48 devvm kernel: jiffies <103828b42> Jun 14 01:10:48 devvm kernel: next_to_watch.status <0> Jun 14 01:10:50 devvm kernel: e1000 0000:00:03.0: eth0: Detected Tx Unit Hang Jun 14 01:10:50 devvm kernel: Tx Queue <0> Jun 14 01:10:50 devvm kernel: TDH <2e> Jun 14 01:10:50 devvm kernel: TDT <30> Jun 14 01:10:50 devvm kernel: next_to_use <30> Jun 14 01:10:50 devvm kernel: next_to_clean <2e> Jun 14 01:10:50 devvm kernel: buffer_info[next_to_clean] Jun 14 01:10:50 devvm kernel: time_stamp <1038284db> Jun 14 01:10:50 devvm kernel: next_to_watch <2f> Jun 14 01:10:50 devvm kernel: jiffies <103829312> Jun 14 01:10:50 devvm kernel: next_to_watch.status <0> Jun 14 01:10:52 devvm kernel: ------------[ cut here ]------------ Jun 14 01:10:52 devvm kernel: WARNING: at net/sched/sch_generic.c:261 dev_watchdog+0x26d/0x280() (Not tainted) Jun 14 01:10:52 devvm kernel: Hardware name: VirtualBox Jun 14 01:10:52 devvm kernel: NETDEV WATCHDOG: eth0 (e1000): transmit queue 0 timed out Jun 14 01:10:52 devvm kernel: Modules linked in: vboxsf(U) ipv6 ppdev parport_pc parport microcode sg vboxguest(U) i2c_piix4 i2c_core e1000 snd_intel8x0 snd_ac97_codec ac97_bus snd_seq snd_seq_device snd_pcm snd_timer snd soundcore snd_page_alloc pcnet32 mii ext4 mbcache jbd2 sd_mod crc_t10dif ahci dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan] Jun 14 01:10:52 devvm kernel: Pid: 0, comm: swapper Not tainted 2.6.32-279.el6.x86_64 #1 Jun 14 01:10:52 devvm kernel: Call Trace: Jun 14 01:10:52 devvm kernel: <IRQ> [<ffffffff8106b747>] ? warn_slowpath_common+0x87/0xc0 Jun 14 01:10:52 devvm kernel: [<ffffffff8106b836>] ? warn_slowpath_fmt+0x46/0x50 Jun 14 01:10:52 devvm kernel: [<ffffffff814595fd>] ? dev_watchdog+0x26d/0x280 Jun 14 01:10:52 devvm kernel: [<ffffffff81099138>] ? sched_clock_cpu+0xb8/0x110 Jun 14 01:10:52 devvm kernel: [<ffffffff81459390>] ? dev_watchdog+0x0/0x280 Jun 14 01:10:52 devvm kernel: [<ffffffff8107e897>] ? run_timer_softirq+0x197/0x340 Jun 14 01:10:52 devvm kernel: [<ffffffff810a21c0>] ? tick_sched_timer+0x0/0xc0 Jun 14 01:10:52 devvm kernel: [<ffffffff8102b40d>] ? lapic_next_event+0x1d/0x30 Jun 14 01:10:52 devvm kernel: [<ffffffff81073ec1>] ? __do_softirq+0xc1/0x1e0 Jun 14 01:10:52 devvm kernel: [<ffffffff81096c50>] ? hrtimer_interrupt+0x140/0x250 Jun 14 01:10:52 devvm kernel: [<ffffffff8100c24c>] ? call_softirq+0x1c/0x30 Jun 14 01:10:52 devvm kernel: [<ffffffff8100de85>] ? do_softirq+0x65/0xa0 Jun 14 01:10:52 devvm kernel: [<ffffffff81073ca5>] ? irq_exit+0x85/0x90 Jun 14 01:10:52 devvm kernel: [<ffffffff81505be0>] ? smp_apic_timer_interrupt+0x70/0x9b Jun 14 01:10:52 devvm kernel: [<ffffffff8100bc13>] ? apic_timer_interrupt+0x13/0x20 Jun 14 01:10:52 devvm kernel: <EOI> [<ffffffff810387cb>] ? native_safe_halt+0xb/0x10 Jun 14 01:10:52 devvm kernel: [<ffffffff810149cd>] ? default_idle+0x4d/0xb0 Jun 14 01:10:52 devvm kernel: [<ffffffff81009e06>] ? cpu_idle+0xb6/0x110 Jun 14 01:10:52 devvm kernel: [<ffffffff814e433a>] ? rest_init+0x7a/0x80 Jun 14 01:10:52 devvm kernel: [<ffffffff81c21f7b>] ? start_kernel+0x424/0x430 Jun 14 01:10:52 devvm kernel: [<ffffffff81c2133a>] ? x86_64_start_reservations+0x125/0x129 Jun 14 01:10:52 devvm kernel: [<ffffffff81c21438>] ? x86_64_start_kernel+0xfa/0x109 Jun 14 01:10:52 devvm kernel: ---[ end trace 2c7bb984812cf120 ]--- Jun 14 01:10:52 devvm kernel: e1000 0000:00:03.0: eth0: Reset adapter Jun 14 01:10:53 devvm abrtd: Directory 'oops-2013-06-14-01:10:53-1537-0' creation detected Jun 14 01:10:53 devvm abrt-dump-oops: Reported 1 kernel oopses to Abrt Jun 14 01:10:53 devvm abrtd: Can't open file '/var/spool/abrt/oops-2013-06-14-01:10:53-1537-0/uid': No such file or directory Jun 14 01:10:55 devvm kernel: Bridge firewalling registered After this we see for a while, every two minutes: Jun 14 01:14:22 devvm kernel: INFO: task events/0:19 blocked for more than 120 seconds. Jun 14 01:14:22 devvm kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Jun 14 01:14:22 devvm kernel: events/0 D 0000000000000000 0 19 2 0x00000000 Jun 14 01:14:22 devvm kernel: ffff880116c4fb90 0000000000000046 00000000ffffffff 0000000000000008 Jun 14 01:14:22 devvm kernel: 0000000000016680 0000000000016680 ffff880028210400 0000000000016680 Jun 14 01:14:22 devvm kernel: ffff880116c4daf8 ffff880116c4ffd8 000000000000fb88 ffff880116c4daf8 Jun 14 01:14:22 devvm kernel: Call Trace: Jun 14 01:14:22 devvm kernel: [<ffffffff8105b483>] ? perf_event_task_sched_out+0x33/0x80 Jun 14 01:14:22 devvm kernel: [<ffffffff814fe6a5>] schedule_timeout+0x215/0x2e0 Jun 14 01:14:22 devvm kernel: [<ffffffff8100975d>] ? __switch_to+0x13d/0x320 Jun 14 01:14:22 devvm kernel: [<ffffffff814fe323>] wait_for_common+0x123/0x180 Jun 14 01:14:22 devvm kernel: [<ffffffff81060250>] ? default_wake_function+0x0/0x20 Jun 14 01:14:22 devvm kernel: [<ffffffff814fe43d>] wait_for_completion+0x1d/0x20 Jun 14 01:14:22 devvm kernel: [<ffffffff8108d093>] __cancel_work_timer+0x1b3/0x1e0 Jun 14 01:14:22 devvm kernel: [<ffffffff8108cbe0>] ? wq_barrier_func+0x0/0x20 Jun 14 01:14:22 devvm kernel: [<ffffffff8108d0f0>] cancel_work_sync+0x10/0x20 Jun 14 01:14:22 devvm kernel: [<ffffffffa01c5ca5>] e1000_down_and_stop+0x25/0x50 [e1000] Jun 14 01:14:22 devvm kernel: [<ffffffffa01cb695>] e1000_down+0x155/0x200 [e1000] Jun 14 01:14:22 devvm kernel: [<ffffffffa01cbcb0>] ? e1000_reset_task+0x0/0xe0 [e1000] Jun 14 01:14:22 devvm kernel: [<ffffffffa01cbd1e>] e1000_reset_task+0x6e/0xe0 [e1000] Jun 14 01:14:22 devvm kernel: [<ffffffff8108c760>] worker_thread+0x170/0x2a0 Jun 14 01:14:22 devvm kernel: [<ffffffff810920d0>] ? autoremove_wake_function+0x0/0x40 Jun 14 01:14:22 devvm kernel: [<ffffffff8108c5f0>] ? worker_thread+0x0/0x2a0 Jun 14 01:14:22 devvm kernel: [<ffffffff81091d66>] kthread+0x96/0xa0 Jun 14 01:14:22 devvm kernel: [<ffffffff8100c14a>] child_rip+0xa/0x20 Jun 14 01:14:22 devvm kernel: [<ffffffff81091cd0>] ? kthread+0x0/0xa0 Jun 14 01:14:22 devvm kernel: [<ffffffff8100c140>] ? child_rip+0x0/0x20 Jun 14 01:14:22 devvm kernel: INFO: task parted:8069 blocked for more than 120 seconds. Jun 14 01:14:22 devvm kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Jun 14 01:14:22 devvm kernel: parted D 0000000000000003 0 8069 7994 0x00000080 Jun 14 01:14:22 devvm kernel: ffff8800908b3bb8 0000000000000082 0000000000000000 ffff88010ab50080 Jun 14 01:14:22 devvm kernel: ffff880116c7d500 0000000000000001 0000000000000000 0000000000000000 Jun 14 01:14:22 devvm kernel: ffff88010ab50638 ffff8800908b3fd8 000000000000fb88 ffff88010ab50638 Jun 14 01:14:22 devvm kernel: Call Trace: Jun 14 01:14:22 devvm kernel: [<ffffffff814fe6a5>] schedule_timeout+0x215/0x2e0 Jun 14 01:14:22 devvm kernel: [<ffffffff814fe323>] wait_for_common+0x123/0x180 Jun 14 01:14:22 devvm kernel: [<ffffffff81060250>] ? default_wake_function+0x0/0x20 Jun 14 01:14:22 devvm kernel: [<ffffffff8112b6d0>] ? lru_add_drain_per_cpu+0x0/0x10 Jun 14 01:14:22 devvm kernel: [<ffffffff814fe43d>] wait_for_completion+0x1d/0x20 Jun 14 01:14:22 devvm kernel: [<ffffffff8108d177>] flush_work+0x77/0xc0 Jun 14 01:14:22 devvm kernel: [<ffffffff8108cbe0>] ? wq_barrier_func+0x0/0x20 Jun 14 01:14:22 devvm kernel: [<ffffffff8108d2f3>] schedule_on_each_cpu+0x133/0x180 Jun 14 01:14:22 devvm kernel: [<ffffffff811ad440>] ? invalidate_bh_lru+0x0/0x50 Jun 14 01:14:22 devvm kernel: [<ffffffff8112ae35>] lru_add_drain_all+0x15/0x20 Jun 14 01:14:22 devvm kernel: [<ffffffff811adf6a>] invalidate_bdev+0x2a/0x50 Jun 14 01:14:22 devvm kernel: [<ffffffff8125e9a4>] blkdev_ioctl+0x3b4/0x6e0 Jun 14 01:14:22 devvm kernel: [<ffffffff811b381c>] block_ioctl+0x3c/0x40 Jun 14 01:14:22 devvm kernel: [<ffffffff8118dec2>] vfs_ioctl+0x22/0xa0 Jun 14 01:14:22 devvm kernel: [<ffffffff8118e064>] do_vfs_ioctl+0x84/0x580 Jun 14 01:14:22 devvm kernel: [<ffffffff8118e5e1>] sys_ioctl+0x81/0xa0 Jun 14 01:14:22 devvm kernel: [<ffffffff8100b0f2>] system_call_fastpath+0x16/0x1b In /var/spool/abrt/oops-2013-06-14-01:10:53-1537-0 we can see the following information: In backtrace: WARNING: at net/sched/sch_generic.c:261 dev_watchdog+0x26d/0x280() (Not tainted) Hardware name: VirtualBox NETDEV WATCHDOG: eth0 (e1000): transmit queue 0 timed out Modules linked in: vboxsf(U) ipv6 ppdev parport_pc parport microcode sg vboxguest(U) i2c_piix4 i2c_core e1000 snd_intel8x0 snd_ac97_codec ac97_bus snd_seq snd_seq_device snd_pcm snd_timer snd soundcore snd_page_alloc pcnet32 mii ext4 mbcache jbd2 sd_mod crc_t10dif ahci dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan] Pid: 0, comm: swapper Not tainted 2.6.32-279.el6.x86_64 #1 Call Trace: <IRQ> [<ffffffff8106b747>] ? warn_slowpath_common+0x87/0xc0 [<ffffffff8106b836>] ? warn_slowpath_fmt+0x46/0x50 [<ffffffff814595fd>] ? dev_watchdog+0x26d/0x280 [<ffffffff81099138>] ? sched_clock_cpu+0xb8/0x110 [<ffffffff81459390>] ? dev_watchdog+0x0/0x280 [<ffffffff8107e897>] ? run_timer_softirq+0x197/0x340 [<ffffffff810a21c0>] ? tick_sched_timer+0x0/0xc0 [<ffffffff8102b40d>] ? lapic_next_event+0x1d/0x30 [<ffffffff81073ec1>] ? __do_softirq+0xc1/0x1e0 [<ffffffff81096c50>] ? hrtimer_interrupt+0x140/0x250 [<ffffffff8100c24c>] ? call_softirq+0x1c/0x30 [<ffffffff8100de85>] ? do_softirq+0x65/0xa0 [<ffffffff81073ca5>] ? irq_exit+0x85/0x90 [<ffffffff81505be0>] ? smp_apic_timer_interrupt+0x70/0x9b [<ffffffff8100bc13>] ? apic_timer_interrupt+0x13/0x20 <EOI> [<ffffffff810387cb>] ? native_safe_halt+0xb/0x10 [<ffffffff810149cd>] ? default_idle+0x4d/0xb0 [<ffffffff81009e06>] ? cpu_idle+0xb6/0x110 [<ffffffff814e433a>] ? rest_init+0x7a/0x80 [<ffffffff81c21f7b>] ? start_kernel+0x424/0x430 [<ffffffff81c2133a>] ? x86_64_start_reservations+0x125/0x129 [<ffffffff81c21438>] ? x86_64_start_kernel+0xfa/0x109 In cmdline: ro root=/dev/mapper/vg_01-lv_root rd_NO_LUKS LANG=en_US.UTF-8 KEYBOARDTYPE=pc KEYTABLE=sv-latin1 rd_NO_MD SYSFONT=latarcyrheb-sun16 rd_LVM_LV=vg_01/lv_root crashkernel=129M@0M rhgb quiet rd_LVM_LV=vg_01/lv_swap rd_NO_DM rhgb quie Additional information: # uname -a Linux devvm 2.6.32-279.el6.x86_64 #1 SMP Fri Jun 22 12:19:21 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux # cat /etc/redhat-release CentOS release 6.3 (Final) VirtualBox version 4.2.6. Any insight in how we can proceed with troubleshooting this is appreciated. If you need more information, just let me know.

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• Application error: fault address 0x00012afb (Expert)

  - by Christian Almeida

  Hi, I need some "light" to get a solution. Probably there are tons of things that cause this problem, but maybe somebody could help me. Scenario: a Windows server running 24/7 a PostgreSQL database and others server applications (for processing tasks on database, etc...). There are differents servers scenarios (~30), with different hardware and windows versions (XP SP3/ WinServer, etc... all NT based). All aplications were written in Delphi7, and link to DLLs (in D7 also). After some days (sometimes a week, sometimes a couple of months), Windows begins to act strange, like not opening start menu, some buttons are missing in dialogs. And soon some applications do not open, raising a event on eventviewer: Faulting application x, version y, faulting module kernel32.dll, version 5.1.2600.5781, fault address 0x00012afb In mean while, others applications open fine, like notepad, iexplore, etc... but SOME of my applications don't, with only event log described above. But if we do not restart system, in a few days even cmd.exe stops open, (and all other applications) with same error on eventlog. I've tried to find 'what' can cause this, but with no sucess. So, and any advice will be welcome. Thanks in advance.

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• C# update GUI continuously from backgroundworker.

  - by Qrew

  I have created a GUI (winforms) and added a backgroundworker to run in a separate thread. The backgroundworker needs to update 2 labels continuously. The backgroundworker thread should start with button1 click and run forever. class EcuData { public int RPM { get; set; } public int MAP { get; set; } } private void button1_Click(object sender, EventArgs e) { EcuData data = new EcuData { RPM = 0, MAP = 0 }; BackWorker1.RunWorkerAsync(data); } private void BackWorker1_DoWork(object sender, DoWorkEventArgs e) { EcuData argumentData = e.Argument as EcuData; int x = 0; while (x<=10) { // // Code for reading in data from hardware. // argumentData.RPM = x; //x is for testing only! argumentData.MAP = x * 2; //x is for testing only! e.Result = argumentData; Thread.Sleep(100); x++; } private void BackWorker1_RunWorkerCompleted_1(object sender, RunWorkerCompletedEventArgs e) { EcuData data = e.Result as EcuData; label1.Text = data.RPM.ToString(); label2.Text = data.MAP.ToString(); } } The above code just updated the GUI when backgroundworker is done with his job, and that's not what I'm looking for.

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• Does Subversion have an analogue to VSS's links?

  - by bta

  I am migrating a Visual SourceSafe code repository to Subversion and I am running into a problem. Here is a simplified layout of our current source code tree (in VSS): project_root\ |-libs\ |-tools\ |-arch_1\ | |-include | |-source |-arch_2\ |-include |-source My problem is in our two arch_ folders. Each arch_ folder will be built for a different hardware architecture, but the contents of the two folders are practically identical. The files in arch_2 are merely VSS links to the files in arch_1, with only a small handful of exceptions. Work is generally checked into and out of the arch_1 folder, and the VSS links make sure that any code checked in here is updated in the arch_2 folder as well. Moving to Subversion, is there anything that will behave like VSS's links? That is, is there a way to have two files in separate folders magically associated with one another such that they will always be in sync with each other (changes to one will affect the other as well)? Note: I know the correct answer here is to fix the build system. The build system on this project was pieced together roughly a decade ago, back when our compiler/build system wasn't intelligent enough to compile the same folder full of source code for two different architectures. Thanks to make and updated compilers, we can re-write the build system to eliminate this dependency on two parallel source folders. However, this will take time that we don't have at the moment (we are losing our license to our VSS server and are being forced to migrate on rather short notice). I am hoping to find a Subversion solution to this problem because at the moment, our time would be much better spent making the migration run smoothly than re-writing the build system (which is next on my to-do list!). Thank you for your help!

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• UIImagePickerController weirdness ...

  - by John Michael Zorko

  Hello, all ... UIImagePickerController is easy to use, but i'm all of a sudden finding it exasperating when I didn't find it so before. What's happening is that sometimes the imagePickerController:didFinishPickingImage:editingInfo delegate method does not seem to work -- the image will not show in the UIImageView even after the assignment was made. Sometimes it will, sometimes not, and furthermore, every single bit of example code i've tried (from the web, from the "Beginning iPhone 3 Development" book, etc.) exhibits the same problem. I'm at a loss as to why, and the problem happens on both my iPhone 3G as well as my 3GS, so I doubt that it's a hardware issue. These devices are running OS 3.1.2. The view controller is loaded from a xib file that contains one button and the UIImageView. I'd really like someone to tell me what stupid thing i'm obviously doing wrong :-) Here is the code -- i've tried to make the smallest app I could that exhibits the problem: #import <UIKit/UIKit.h> #import <Foundation/Foundation.h> @interface imagepickerViewController : UIViewController <UINavigationControllerDelegate, UIImagePickerControllerDelegate> { IBOutlet UIButton *button; IBOutlet UIImageView *imageView; } @property (nonatomic, retain) UIImageView *imageView; - (IBAction)takepic; - (void)usePic:(UIImage *)pic; @end #import "imagepickerViewController.h" @implementation imagepickerViewController @synthesize imageView; - (IBAction)takepic { if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) { UIImagePickerController *picker = [[UIImagePickerController alloc] init]; picker.sourceType = UIImagePickerControllerSourceTypeCamera; picker.delegate = self; [self presentModalViewController:picker animated:YES]; [picker release]; } } - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary *)info { [self usePic:image]; [picker dismissModalViewControllerAnimated:YES]; // after this method returns, the UIImageView should show the image -- yet very often it does not ... } - (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker { [picker dismissModalViewControllerAnimated:YES]; } - (void)usePic:(UIImage *)picture { imageView.image = picture; } @end

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• Really slow obtaining font metrics.

  - by Artur

  So the problem I have is that I start my application by displaying a simple menu. To size and align the text correctly I need to obtain font metrics and I cannot find a way to do it quickly. I tested my program and it looks like whatever method I use to obtain font metrics the first call takes over 500 milliseconds!? Because of it the time it takes to start-up my application is much longer than necessary. I don't know if it is platform specific or not, but just in case, I'm using Mac OS 10.6.2 on MacBook Pro (hardware isn't an issue here). If you know a way of obtaining font metrics quicker please help. I tried these 3 methods for obtaining the font metrics and the first call is always very slow, no matter which method I choose. import java.awt.Font; import java.awt.FontMetrics; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.font.FontRenderContext; import java.awt.font.LineMetrics; import javax.swing.JFrame; public class FontMetricsTest extends JFrame { public FontMetricsTest() { setVisible(true); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } @Override public void paint(Graphics g) { Graphics2D g2 = (Graphics2D) g; Font font = new Font("Dialog", Font.BOLD, 10); long start = System.currentTimeMillis(); FontMetrics fontMetrics = g2.getFontMetrics(font); // LineMetrics fontMetrics1 = // font.getLineMetrics("X", new FontRenderContext(null, false, false)); // FontMetrics fontMetrics2 = g.getFontMetrics(); long end = System.currentTimeMillis(); System.out.println(end - start); g2.setFont(font); } public static void main(String[] args) { new FontMetricsTest(); } }

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• DotNetOpenAuth RelayParty not working on load balanced cluster

  - by Garth

  We're trying to move an ASP.NET MVC application, which uses DotNetOpenAuth OpenID Version 3.4.1, from a single server web garden to a physical server cluster held behind a hardware load balancer. Our old setup (OpenID RP working): Browser = SHTTP = Server = WebGarden = Nonce/Session Store Our new setup (OpenID RP not working): Browser = SHTTP = Load Balancer = HTTP = Cluster Node = WebGarden = Nonce/Session Store DB When we authenticate with the new setup we are correctly redirected to the OpenID Provider but after authenticated we are redirected back to our cluster (relay party) and get the following exception: Exception DotNetOpenAuth.Messaging.ProtocolException: Redirects on POST requests that are to untrusted servers is not supported. at DotNetOpenAuth.Messaging.ErrorUtilities.VerifyProtocol(Boolean condition, String message, Object[] args) in c:\TeamCity\buildAgent\work\bf9e2ca68b75a334\src\DotNetOpenAuth\Messaging\ErrorUtilities.cs:line 235 at DotNetOpenAuth.Messaging.UntrustedWebRequestHandler.GetResponse(HttpWebRequest request, DirectWebRequestOptions options) in c:\TeamCity\buildAgent\work\bf9e2ca68b75a334\src\DotNetOpenAuth\Messaging\UntrustedWebRequestHandler.cs:line 258 at DotNetOpenAuth.OpenId.ChannelElements.OpenIdChannel.GetDirectResponse(HttpWebRequest webRequest) in c:\TeamCity\buildAgent\work\bf9e2ca68b75a334\src\DotNetOpenAuth\OpenId\ChannelElements\OpenIdChannel.cs:line 277 at DotNetOpenAuth.Messaging.Channel.RequestCore(IDirectedProtocolMessage request) in c:\TeamCity\buildAgent\work\bf9e2ca68b75a334\src\DotNetOpenAuth\Messaging\Channel.cs:line 542 at DotNetOpenAuth.Messaging.Channel.Request(IDirectedProtocolMessage requestMessage) in c:\TeamCity\buildAgent\work\bf9e2ca68b75a334\src\DotNetOpenAuth\Messaging\Channel.cs:line 425 at DotNetOpenAuth.Messaging.Channel.Request[TResponse](IDirectedProtocolMessage requestMessage) in c:\TeamCity\buildAgent\work\bf9e2ca68b75a334\src\DotNetOpenAuth\Messaging\Channel.cs:line 405 at DotNetOpenAuth.OpenId.ChannelElements.SigningBindingElement.ProcessIncomingMessage(IProtocolMessage message) in c:\TeamCity\buildAgent\work\bf9e2ca68b75a334\src\DotNetOpenAuth\OpenId\ChannelElements\SigningBindingElement.cs:line 154 at DotNetOpenAuth.Messaging.Channel.ProcessIncomingMessage(IProtocolMessage message) in c:\TeamCity\buildAgent\work\bf9e2ca68b75a334\src\DotNetOpenAuth\Messaging\Channel.cs:line 992 at DotNetOpenAuth.OpenId.ChannelElements.OpenIdChannel.ProcessIncomingMessage(IProtocolMessage message) in c:\TeamCity\buildAgent\work\bf9e2ca68b75a334\src\DotNetOpenAuth\OpenId\ChannelElements\OpenIdChannel.cs:line 172 at DotNetOpenAuth.Messaging.Channel.ReadFromRequest(HttpRequestInfo httpRequest) in c:\TeamCity\buildAgent\work\bf9e2ca68b75a334\src\DotNetOpenAuth\Messaging\Channel.cs:line 386 at DotNetOpenAuth.OpenId.RelyingParty.OpenIdRelyingParty.GetResponse(HttpRequestInfo httpRequestInfo) in c:\TeamCity\buildAgent\work\bf9e2ca68b75a334\src\DotNetOpenAuth\OpenId\RelyingParty\OpenIdRelyingParty.cs:line 501 We have added a machines involved into the trusted machine list and turned off requires ssl but it makes no difference. We even tried removing out nonce store and using a stateless connection, but that didn't work either. We always get the same error. We suspected the issue is arising as a result of the cluster node having a different IP from the load balancer when it connects to the OpenID Provider, but we're not sure. Any ideas?

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• how many types of code signing certificates do I need?

  - by gerryLowry

  in Canada, website SSL certificates can be had for as low as US$10. unfortunately, code signing certificates cost about 10 time as much, one website mentions Vista compatibility ... this seems strange because my assumption is they must support XP, Vista, Windows 7, Server 2003, and Server 2008 or they would be useless. https://secure.ksoftware.net/code_signing.html US$99 Support Platforms Microsoft Authenticode. Sign any Microsoft executable format (32 and 64 bit EXE, DLL, OCX, DLL or any Active X control). Signing hardware drivers is not currently supported. Abode AIR. Sign any Adobe AIR application. Java. Sign any JAR applet Microsoft Office. Sign any MS Office Macro or VBA (Visual Basic for Applications) file. Mozilla. Sign any Mozilla Object file. The implication is that a single code signing certificate can do ALL of the above. ksoftware actually discounts Commodo certificates and the Commode website is unclear. QUESTION: Will ONE code signing certificate be enough or do I need one for Microsoft executables, and a second for things like Word and Excel macros? my main goal is to sign things like vs2008 code snippets so that I can export them securely; however, I would like to be able to use the same code signing certificate for signing other items too. Thank you ~~ regards, Gerry (Lowry)

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• Suggestions for doing async I/O with Task Parallel Library

  - by anelson

  I have some high performance file transfer code which I wrote in C# using the Async Programming Model (APM) idiom (eg, BeginRead/EndRead). This code reads a file from a local disk and writes it to a socket. For best performance on modern hardware, it's important to keep more than one outstanding I/O operation in flight whenever possible. Thus, I post several BeginRead operations on the file, then when one completes, I call a BeginSend on the socket, and when that completes I do another BeginRead on the file. The details are a bit more complicated than that but at the high level that's the idea. I've got the APM-based code working, but it's very hard to follow and probably has subtle concurrency bugs. I'd love to use TPL for this instead. I figured Task.Factory.FromAsync would just about do it, but there's a catch. All of the I/O samples I've seen (most particularly the StreamExtensions class in the Parallel Extensions Extras) assume one read followed by one write. This won't perform the way I need. I can't use something simple like Parallel.ForEach or the Extras extension Task.Factory.Iterate because the async I/O tasks don't spend much time on a worker thread, so Parallel just starts up another task, resulting in potentially dozens or hundreds of pending I/O operations; way too much! You can work around that by Waiting on your tasks, but that causes creation of an event handle (a kernel object), and a blocking wait on a task wait handle, which ties up a worker thread. My APM-based implementation avoids both of those things. I've been playing around with different ways to keep multiple read/write operations in flight, and I've managed to do so using continuations that call a method that creates another task, but it feels awkward, and definitely doesn't feel like idiomatic TPL. Has anyone else grappled with an issue like this with the TPL? Any suggestions?

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• Static IP for dynamic IP

  - by scape279

  I have a dynamic IP address. I would like to have a static IP, but Virgin Media don't allow static IPs for residential broadband services, even if you ask them really nicely and offer to pay for it without switching to a business tariff. I am already registered with a dynamic DNS service which is updated by my router eg me.example.com will always resolve to my dynamic IP. This is fine for some circumstances, but not if you can only enter an IP address into configuration files/hardware etc like firewalls, subversion services etc etc. Is there a way I can have a static IP address 'forwarding' to my dynamic IP? Would a possible solution involve tunnelling? Setting up a private proxy? Please note the following: I am able to buy an IP address from my web host. I have access to a webserver and I am able to create custom DNS zones. I'm happy to have a webserver running at home if necessary also. I do not wish to change broadband providers. I have zero control over the services that require the IP address entering so I cannot tackle the problem that way round (services I need to access are at work). PS I've tried googling this issue, but it is very difficult to search for as most results are related to dynamic dns (which I already have set up and isnt quite what I'm after)

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• [NSLocale currentLocale] always returns "en_US" not user's current language

  - by Prairiedogg

  I'm in the processes of internationalizing an iPhone app - I need to make programmatic changes to certain views based on what the user's current locale is. I'm going nuts because no matter what the language preference on the iPhone simulator or actual hardware are, locale always evaluates to "en_US": NSString *locale = [[NSLocale currentLocale] localeIdentifier]; NSLog(@"current locale: %@", locale); The crazy thing is that the rest of the application behaves as expected. The correct strings are selected from the Localization.strings file and used in the interface, and the correct .xib files for the selected locale are used. I have also tried the following, to no avail and with the same result: NSString *locale = [[NSLocale autoupdatingCurrentLocale] localeIdentifier]; NSLog(@"current locale: %@", locale); Is there something simple I'm missing? A preference or an import perhaps? Update: As Darren's answer suggests, the preference I'm looking for is not in NSLocale, rather it is here: NSUserDefaults* defs = [NSUserDefaults standardUserDefaults]; NSArray* languages = [defs objectForKey:@"AppleLanguages"]; NSString* preferredLang = [languages objectAtIndex:0]; NSLog(@"preferredLang: %@", preferredLang);

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• EAAccessory Notification problem

  - by Deepak

  Hi, I am using a POS device for card swipe. its working good. i have used following codes. (id) init { self = [super init]; if (self != nil) { NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter]; EAAccessoryManager *accessoryMamaner = [EAAccessoryManager sharedAccessoryManager]; [accessoryMamaner registerForLocalNotifications]; [notificationCenter addObserver: self selector: @selector (accessoryDidConnect:) name: EAAccessoryDidConnectNotification object: nil]; [notificationCenter addObserver: self selector: @selector (accessoryDidDisconnect:) name: EAAccessoryDidDisconnectNotification object: nil]; NSArray *accessories = [accessoryMamaner connectedAccessories]; accessory = nil; session = nil; for (EAAccessory *obj in accessories) { if ([[obj protocolStrings] containsObject:@"com.XXXXX"] || [[obj protocolStrings] containsObject:@"com.YYYYYY"] ) { accessory = obj; break; } } if (accessory) { session = [[EASession alloc] initWithAccessory:accessory forProtocol:@"com.dailysystems.DS247"]; if (!session) session = [[EASession alloc] initWithAccessory:accessory forProtocol:@"com.usaepay.ipos"]; if (session) { self.deviceConnected = YES; [[session inputStream] setDelegate:self]; [[session inputStream] scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; [[session inputStream] open]; [[session outputStream] setDelegate:self]; [[session outputStream] scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; [[session outputStream] open]; } else { UIAlertView *accessoryInfo = [[UIAlertView alloc] initWithTitle:@"Alert!" message:@"Hardware is not connected." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [accessoryInfo show]; [accessoryInfo release]; } } } return self; } When i disconnect the accessory it gives me accessoryDidDisconnect and when i connect it gives me accessoryDidConnect, But Problem is after that accessory stop working it does not respond to command. i tried to release the alloc and alloc again but no use. Please tell me if some one have any idea how to get the accessory work again. Thanks in advance.

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• Navigating through a sea of hype

  - by wouldLikeACrystalBall

  This is a vague, open question, so if you have no interest in these, please leave now. A few years ago it seemed everyone thought the death of desktop software was imminent. Web applications were the future. Everyone would move to cloud-based software-as-a-service systems, and developing applications for specific end-user platforms like Windows would soon become something of a ghetto. Joel's "How Microsoft Lost the API War" was but one of many such pieces sounding the death knell for this way of software development. Flash-forward to 2010, and the hype is all around mobile devices, particularly the iPhone. Software-as-a-Service vendors--even small ones such as YCombinator startups--go out of their way to build custom applications for the iPhone and other smart phone devices; applications that can be quite sophisticated, that run only on specific hardware and software architectures and are thus inherently incompatible. Now some of you are probably thinking, "Well, only the decline of desktop software was predicted; mobile devices aren't desktops." But the term was used by those predicting its demise to mean laptops also, and really any platform capable of running a browser. What was promised was a world where HTML and related standards would supplant native applications and their inherent difficulties. We would all code to the browser, not the OS. But here we are in 2010 with the AppStore bulging and development for the iPad just revving up. A few days ago, I saw someone on Hacker News claim that the future of computing was entirely in small, portable devices. Apparently the future is underpowered, requires dexterous thumbs and induces near-sightedness. How do those who so vehemently asserted one thing now assert the opposite with equal vehemence, without making even the slightest admission of error? And further, how are we as developers supposed to sift through all of this? I bought into the whole web-standards utopianism that was in vogue back in '06-'07 and now feel like it was a mistake. Is there some formula one can apply rather than a mere appeal to experience?

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