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• Cloud Deployment Models

  - by B R Clouse

  Normal 0 false false false EN-US X-NONE X-NONE As the cloud paradigm grows in depth and breadth, more readers are approaching the topic for the first time, or from a new perspective.  This blog is a basic review of  cloud deployment models, to help orient newcomers and neophytes. Most cloud deployments today are either private or public. It is also possible to connect a private cloud and a public cloud to form a hybrid cloud. A private cloud is for the exclusive use of an organization. Enterprises, universities and government agencies throughout the world are using private clouds. Some have designed, built and now manage their private clouds. Others use a private cloud that was built by and is now managed by a provider, hosted either onsite or at the provider’s datacenter. Because private clouds are for exclusive use, they are usually the option chosen by organizations with concerns about data security and guaranteed performance. Public clouds are open to anyone with an Internet connection. Because they require no capital investment from their users, they are particularly attractive to companies with limited resources in less regulated environments and for temporary workloads such as development and test environments. Public clouds offer a range of products, from end-user software packages to more basic services such as databases or operating environments. Public clouds may also offer cloud services such as a disaster recovery for a private cloud, or the ability to “cloudburst” a temporary workload spike from a private cloud to a public cloud. These are examples of a hybrid cloud. These are most feasible when the private and public clouds are built with similar technologies. Usually people think of a public cloud in terms of a user role, e.g., “Which public cloud should I consider using?” But someone needs to own and manage that public cloud. The company who owns and operates a public cloud is known as a public cloud provider. Oracle Database Cloud Service, Amazon RDS, database.com and Savvis Symphony Database are examples of public cloud database services. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} When evaluating deployment models, be aware that you can use any or all of the available options. Some workloads may be best-suited for a private cloud, some for a public or hybrid cloud. And you might deploy multiple private clouds in your organization. If you are going to combine multiple clouds, then you want to make sure that each cloud is based on a consistent technology portfolio and architecture. This simplifies management and gives you the greatest flexibility in moving resources and workloads among your different clouds. Oracle’s portfolio of cloud products and services enables both deployment models. Oracle can manage either model. Universities, government agencies and companies in all types of business everywhere in the world are using clouds built with the Oracle portfolio. By employing a consistent portfolio, these customers are able to run all of their workloads – from test and development to the most mission-critical -- in a consistent manner: One Enterprise Cloud, powered by Oracle.   /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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• 2012&ndash;The End Of The World Review

  - by Tim Murphy

  The end of the world must be coming.  Not because the Mayan calendar says so, but because Microsoft is innovating more than Apple.  It has been a crazy year, with pundits declaring not that the end of the world is coming, but that the end of Microsoft is coming.  Let’s take a look at what 2012 has brought us. The beginning of year is a blur.  I managed to get to TechEd in June which was the first time that I got to take a deep dive into Windows 8 and many other things that had been announced in 2011.  The promise I saw in these products was really encouraging.  The thought of being able to run Windows 8 from a thumb drive or have Hyper-V native to the OS told me that at least for developers good things were coming. I finally got my feet wet with Windows 8 with the developer preview just prior to the RTM.  While the initial experience was a bit of a culture shock I quickly grew to love it.  The media still seems to hold little love for the “reimagined” platform, but I think that once people spend some time with it they will enjoy the experience and what the FUD mongers say will fade into the background.  With the launch of the OS we finally got a look at the Surface.  I think this is a bold entry into the tablet market.  While I wish it was a little more affordable I am already starting to see them in the wild being used by non-techies. I was waiting for Windows Phone 8 at least as much as Windows 8, probably more.  The new hardware, better marketing and new OS features I think are going to finally push us to the point of having a real presence in the smartphone market.  I am seeing a number of iPhone users picking up a Nokia Lumia 920 and getting rid of their brand new iPhone 5.  The only real debacle that I saw around the launch was when they held back the SDK from general developers. Shortly after the launch events came Build 2012.  I was extremely disappointed that I didn’t make it to this year’s Build.  Even if they weren’t handing out Surface and Lumia devices I think the atmosphere and content were something that really needed to be experience in person.  Hopefully there will be a Build next year and it’s schedule will be announced soon.  As you would expect Windows 8 and Windows Phone 8 development were the mainstay of the conference, but improvements in Azure also played a key role.  This movement of services to the cloud will continue and we need to understand where it best fits into the solutions we build. Lower on the radar this year were Office 2013, SQL Server 2012, and Windows Server 2012.  Their glory stolen by the consumer OS and hardware announcements, these new releases are no less important.  Companies will see significant improvements in performance and capabilities if they upgrade.  At TechEd they had shown some of the new features of Windows Server 2012 around hardware integration and Hyper-V performance which absolutely blew me away.  It is our job to bring these important improvements to our company’s attention so that they can be leveraged. Personally, the consulting business in 2012 was the busiest it has been in a long time.  More companies were ready to attack new projects after several years of putting them on the back burner.  I also worked to bring back momentum to the Chicago Information Technology Architects Group.  Both the community and clients are excited about the new technologies that have come out in 2012 and now it is time to deliver. What does 2013 have in store.  I don’t see it be quite as exciting as 2012.  Microsoft will be releasing the Surface Pro in January and it seems that we will see more frequent OS update for Windows.  There are rumors that we may see a Surface phone in 2013.  It has also been announced that there will finally be a rework of the XBox next fall.  The new year will also be a time for us in the development community to take advantage of these new tools and devices.  After all, it is what we build on top of these platforms that will attract more consumers and corporations to using them. Just as I am 99.999% sure that the world is not going to end this year, I am also sure that Microsoft will move on and that most of this negative backlash from the media is actually fear and jealousy.  In the end I think we have a promising year ahead of us. del.icio.us Tags: Microsoft,Pundits,Mayans,Windows 8,Windows Phone 8,Surface

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• Building a Repository Pattern against an EF 5 EDMX Model - Part 1

  - by Juan

  I am part of a year long plus project that is re-writing an existing application for a client.  We have decided to develop the project using Visual Studio 2012 and .NET 4.5.  The project will be using a number of technologies and patterns to include Entity Framework 5, WCF Services, and WPF for the client UI.This is my attempt at documenting some of the successes and failures that I will be coming across in the development of the application.In building the data access layer we have to access a database that has already been designed by a dedicated dba. The dba insists on using Stored Procedures which has made the use of EF a little more difficult.  He will not allow direct table access but we did manage to get him to allow us to use Views.  Since EF 5 does not have good support to do Code First with Stored Procedures, my option was to create a model (EDMX) against the existing database views.   I then had to go select each entity and map the Insert/Update/Delete functions to their respective stored procedure. The next step after I had completed mapping the stored procedures to the entities in the EDMX model was to figure out how to build a generic repository that would work well with Entity Framework 5.  After reading the blog posts below, I adopted much of their code with some changes to allow for the use of Ninject for dependency injection.http://www.tcscblog.com/2012/06/22/entity-framework-generic-repository/ http://www.tugberkugurlu.com/archive/generic-repository-pattern-entity-framework-asp-net-mvc-and-unit-testing-triangle IRepository.cs public interface IRepository : IDisposable where T : class { void Add(T entity); void Update(T entity, int id); T GetById(object key); IQueryable Query(Expression> predicate); IQueryable GetAll(); int SaveChanges(); int SaveChanges(bool validateEntities); } GenericRepository.cs public abstract class GenericRepository : IRepository where T : class { public abstract void Add(T entity); public abstract void Update(T entity, int id); public abstract T GetById(object key); public abstract IQueryable Query(Expression> predicate); public abstract IQueryable GetAll(); public int SaveChanges() { return SaveChanges(true); } public abstract int SaveChanges(bool validateEntities); public abstract void Dispose(); } One of the issues I ran into was trying to do an update. I kept receiving errors so I posted a question on Stack Overflow http://stackoverflow.com/questions/12585664/an-object-with-the-same-key-already-exists-in-the-objectstatemanager-the-object and came up with the following hack. If someone has a better way, please let me know. DbContextRepository.cs public class DbContextRepository : GenericRepository where T : class { protected DbContext Context; protected DbSet DbSet; public DbContextRepository(DbContext context) { if (context == null) throw new ArgumentException("context"); Context = context; DbSet = Context.Set(); } public override void Add(T entity) { if (entity == null) throw new ArgumentException("Cannot add a null entity."); DbSet.Add(entity); } public override void Update(T entity, int id) { if (entity == null) throw new ArgumentException("Cannot update a null entity."); var entry = Context.Entry(entity); if (entry.State == EntityState.Detached) { var attachedEntity = DbSet.Find(id); // Need to have access to key if (attachedEntity != null) { var attachedEntry = Context.Entry(attachedEntity); attachedEntry.CurrentValues.SetValues(entity); } else { entry.State = EntityState.Modified; // This should attach entity } } } public override T GetById(object key) { return DbSet.Find(key); } public override IQueryable Query(Expression> predicate) { return DbSet.Where(predicate); } public override IQueryable GetAll() { return Context.Set(); } public override int SaveChanges(bool validateEntities) { Context.Configuration.ValidateOnSaveEnabled = validateEntities; return Context.SaveChanges(); } #region IDisposable implementation public override void Dispose() { if (Context != null) { Context.Dispose(); GC.SuppressFinalize(this); } } #endregion IDisposable implementation } At this point I am able to start creating individual repositories that are needed and add a Unit of Work.  Stay tuned for the next installment in my path to creating a Repository Pattern against EF5.

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• How do I dig myself out of this DEEP hole? [closed]

  - by user74847

  I may be a bit bias in the way i word this but any opinions and suggestions are welcome. I should start by saying i have a MSc in CS and a degree in new media +6 years expereince and im probably around a middleweight developer. I started a web development company with my friend from uni a year ago, there was a 4 month gap in the middle where i went miles away work on a big project. Ive since returned and picked up where we left off. A year on though i find im still staying up til 5am and getting up at 9 sometimes 2-3 days without sleep. While i was away i was working 9-5 and struggling to keep up with doing stuff for my clients 8 hours ahead, after work, so things stagnated. We currently have about 12 active projects, with one other part time developer and a full time freelancer who is dealing with one of our major projects. I am solely responsible for concurrently developing 2 big sites similar to gumtree in functionality, at the same time as about 5-6+ small WordPress based 5-10page sites. a lot of the content isnt in yet or the client is delaying so i chop and change project every other day which does my head in. Is it reasonable to expect myself to remember the intricate details of each project when i come back to it a week later? and remember the details of a task which hasnt been written down? my business partner seems to think so. or am i just forgetful? Im particularly bad at estimating timescales which doesnt help, added to that a lot of the technologies im am using are new to me (a magento site took weeks to theme rather than days and was full of bugs, even after 1000's of google searches and hours reading forums) im still trying to learn and find the best CMS for us to use and getting my head around the likes of Bootstrap and jquery, Cpanel / Linux (we just got a blank vps for me to set up with no experience) even installing an SSL certificate caused everyone's mail clients to go down which was more stress for me to sort out. I find the pressure of the workload and timescales and trying to learn this stuff so fast is beginning to turn me against my career path. The fact that i never seem to get anything done really winds up my business partner and iv come to associate him with the stress and pain of the whole situation especially when I get berated or a look that says "oh you retard" when I forget something. Even today i spent hours learning how a particular themeforest theme worked with wordpress and how i could twist it to work for our partiuclar needs, on the surface had done no work, that triggered a 30 minute tirade of anger and stress and questioning what i had done from my business partner. had i taken too long to work on that? shoudl i have done it in 2 hours instead of 6? i told him i would take 2 hours. i was wrong. I feel like im running myself into the ground. My sleeping pattern has got so bad that when im working im half asleep and making mistakes, my eyes are constantly purple underneath, i literally fall asleep at my desk, its affecting my social life too, ive not slept more than lightly for the last year and grind through impossible code puzzles in my half sleep wich keeps me awake, when im already exhausted. plus the work is rushed and buggy when it does get done so drags on into the next project. I also procrastinate quite badly, pacing the livingroom, looking out the window when Im alone for three days straight in the flat and start to get cabin fever which means i do even less work and the negative feedback loop continues. I get told im the only one with the problem when i say that i cant work from home any more, and examples of other freelancers get brought up. an office wouldnt bring any extra cash in to the company but im convinced having that moving more than 2 meters away from my bed to go to "work" would get me working, at the moment i feel guilty like i should be working 24-7. It is important that we do all this work to raise enough cash to get our business to the next level but every month still feels like a struggle to pay the rent (there is about £20K coming in by Jan) and i have to borrow money from friends often to buy food or get a taxi to a meeting, so it is vital the money keeps coming in. (im also 20 mins late for nearly all meetings but thats a different issue) have you experienced anything similar? how can i deal with the issues ive raised? is it realistic to develop 10 sites at once? how can i improve my relationship with my business partner? do you struggle to work at home? how do you deal with that? i think if i dont get my life on track by feb i will seriously consider giving it all up, but that seems like such a waste. any ideas!!? i need help! Thanks.

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• Revisiting the Generations

  - by Row Henson

  I was asked earlier this year to contribute an article to the IHRIM publication – Workforce Solutions Review.  My topic focused on the reality of the Gen Y population 10 years after their entry into the workforce.  Below is an excerpt from that article: It seems like yesterday that we were all talking about the entry of the Gen Y'ers into the workforce and what a radical change that would have on how we attract, retain, motivate, reward, and engage this new, younger segment of the workforce.  We all heard and read that these youngsters would be more entrepreneurial than their predecessors – the Gen X'ers – who were said to be more loyal to their profession than their employer. And, we heard that these “youngsters” would certainly be far less loyal to their employers than the Baby Boomers or even earlier Traditionalists. It was also predicted that – at least for the developed parts of the world – they would be more interested in work/life balance than financial reward; they would need constant and immediate reinforcement and recognition and we would be lucky to have them in our employment for two to three years. And, to keep them longer than that we would need to promote them often so they would be continuously learning since their long-term (10-year) goal would be to own their own business or be an independent consultant.  Well, it occurred to me recently that the first of the Gen Y'ers are now in their early 30s and it is time to look back on some of these predictions. Many really believed the Gen Y'ers would enter the workforce with an attitude – expect everything to be easy for them – have their employers meet their demands or move to the next employer, and I believe that we can now say that, generally, has not been the case. Speaking from personal experience, I have mentored a number of Gen Y'ers and initially felt that with a 40-year career in Human Resources and Human Resources Technology – I could share a lot with them. I found out very quickly that I was learning at least as much from them! Some of the amazing attributes I found from these under-30s was their fearlessness, ease of which they were able to multi-task, amazing energy and great technical savvy. They were very comfortable with collaborating with colleagues from both inside the company and peers outside their organization to problem-solve quickly. Most were eager to learn and willing to work hard.  This brings me to the generation that will follow the Gen Y'ers – the Generation Z'ers – those born after 1998. We have come full circle. If we look at the Silent Generation or Traditionalists, we find a workforce that preceded the television and even very early telephones. We Baby Boomers (as I fall right squarely in this category) remembered the invention of the television and telephone – but laptop computers and personal digital assistants (PDAs) were a thing of “StarTrek” and other science fiction movies and publications. Certainly, the Gen X'ers and Gen Y'ers grew up with the comfort of these devices just as we did with calculators. But, what of those under the age of 10 – how will the workplace look in 15 more years and what type of workforce will be required to operate in the mobile, global, virtual world. I spoke to a friend recently who had her four-year-old granddaughter for a visit. She said she found her in the den in front of the TV trying to use her hand to get the screen to move! So, you see – we have come full circle. The under-70 Traditionalist grew up in a world without TV and the Generation Z'er may never remember the TV we knew just a few years ago. As with every generation – we spend much time generalizing on their characteristics. The most important thing to remember is every generation – just like every individual – is different. The important thing for those of us in Human Resources to remember is that one size doesn’t fit all. What motivates one employee to come to work for you and stay there and be productive is very different than what the next employee is looking for and the organization that can provide this fluidity and flexibility will be the survivor for generations to come. And, finally, just when we think we have it figured out, a multitude of external factors such as the economy, world politics, industries, and technologies we haven’t even thought about will come along and change those predictions. As I reach retirement age – I do so believing that our organizations are in good hands with the generations to follow – energetic, collaborative and capable of working hard while still understanding the need for balance at work, at home and in the community! 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• IE9, LightSwitch Beta 2 and Zune HD: A Study in Risk Management?

  - by andrewbrust

  Photo by parl, 'Risk.’ Under Creative Commons Attribution-NonCommercial-NoDerivs License This has been a busy week for Microsoft, and for me as well.  On Monday, Microsoft launched Internet Explorer 9 at South by Southwest (SXSW) in Austin, TX.  That evening I flew from New York to Seattle.  On Tuesday morning, Microsoft launched Visual Studio LightSwitch, Beta 2 with a Go-Live license, in Redmond, and I had the privilege of speaking at the keynote presentation where the announcement was made.  Readers of this blog know I‘m a fan of LightSwitch, so I was happy to tell the app dev tools partners in the audience that I thought the LightSwitch extensions ecosystem represented a big opportunity – comparable to the opportunity when Visual Basic 1.0 was entering its final beta roughly 20 years ago.  On Tuesday evening, I flew back to New York (and wrote most of this post in-flight). Two busy, productive days.  But there was a caveat that impacts the accomplishments, because Monday was also the day reports surfaced from credible news agencies that Microsoft was discontinuing its dedicated Zune hardware efforts.  While the Zune brand, technology and service will continue to be a component of Windows Phone and a piece of the Xbox puzzle as well, speculation is that Microsoft will no longer be going toe-to-toe with iPod touch in the portable music player market. If we take all three of these developments together (even if one of them is based on speculation), two interesting conclusions can reasonably be drawn, one good and one less so. Microsoft is doubling down on technologies it finds strategic and de-emphasizing those that it does not.  HTML 5 and the Web are strategic, so here comes IE9, and it’s a very good browser.  Try it and see.  Silverlight is strategic too, as is SQL Server, Windows Azure and SQL Azure, so here comes Visual Studio LightSwitch Beta 2 and a license to deploy its apps to production.  Downloads of that product have exceeded Microsoft’s projections by more than 50%, and the company is even citing analyst firms’ figures covering the number of power-user developers that might use it. (I happen to think the product will be used by full-fledged developers as well, but that’s a separate discussion.) Windows Phone is strategic too…I wasn’t 100% positive of that before, but the Nokia agreement has made me confident.  Xbox as an entertainment appliance is also strategic.  Standalone music players are not strategic – and even if they were, selling them has been a losing battle for Microsoft.  So if Microsoft has consolidated the Zune content story and the ZunePass subscription into Xbox and Windows Phone, it would make sense, and would be a smart allocation of resources.  Essentially, it would be for the greater good. But it’s not all good.  In this scenario, Zune player customers would lose out.  Unless they wanted to switch to Windows Phone, and then use their phone’s battery for the portable media needs, they’re going to need a new platform.  They’re going to feel abandoned.  Even if Zune lives, there have been other such cul de sacs for customers.  Remember SPOT watches?  Live Spaces?  The original Live Mesh?  Microsoft discontinued each of these products.  The company is to be commended for cutting its losses, as admitting a loss isn’t easy.  But Redmond won’t be well-regarded by the victims of those decisions.  Instead, it gets black marks. What’s the answer?  I think it’s a bit like the 1980’s New York City “don’t block the box” gridlock rules: don’t enter an intersection unless you see a clear path through it.  If the light turns red and you’re blocking the perpendicular traffic, that’s your fault in judgment.  You get fined and get points on your license and you don’t get to shrug it off as beyond your control.  Accountability is key.  The same goes for Microsoft.  If it decides to enter a market, it should see a reasonable path through success in that market. Switching analogies, Microsoft shouldn’t make investments haphazardly, and it certainly shouldn’t ask investors to buy into a high-risk fund that is sold as safe and which offers only moderate returns.  People won’t continue to invest with a fund manager with a track record of over-zealous, imprudent, sub-prime investments.  The same is true on the product side for Microsoft, and not just with music players and geeky wrist watches.  It’s true of Web browsers, and line-of-business app dev tools, and smartphones, and cloud platforms and operating systems too.  When Microsoft is casual about its own risk, it raises risk for its customers, and weakens its reputation, market share and credibility.  That doesn’t mean all risk is bad, but it does mean no product team’s risk should be taken lightly. For mutual fund companies, it’s the CEO’s job to give his fund managers autonomy, but to make sure they’re conforming to a standard of rational risk management.  Because all those funds carry the same brand, and many of them serve the same investors. The same goes for Microsoft, its product portfolio, its executive ranks and its product managers.

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• Are there Negative Impact of opensource on commercial environment?

  - by Lostsoul

  I know this is not a good fit for Stack Overflow but wasn't sure if it was good for this site also so let me know if its not and I'll delete it. I love programming for fun but my role in my company is not technical. I have always loved the hacker culture and have been trying to drive that openness within my company from day one. My company has a very broad range of products and there are a few that are not strategic to us so I wanted to open source them (so we can focus on what makes us unique and open source the products that every firm has). Our industry does not open source(we would be the first firm to try this) and the feedback I'm getting from my management team is either 1) we'll destroy the industry or 2) all competitive commercial firms will unite against us and we'll be wiped out either way. I disagreed on both points because I think transparency will only grow our industry and our firm (think of McDonalds/KFC sharing their recipe openly, people may copy you, competitors may target you, but customers also may feel more comfortable buying your product. The value add, I believe, is in the delivery and experience not in hoarding the recipe). It's a big battle in my firm right now between the IT people who have seen the positive effects of sharing and the business people who think we'll be giving up everything (they prefer we sell parts we want to opensource, but in their defense this is standard when divesting something). Our industry is very secretive and I don't want to put anyone(even my competitors employees) out of a job yet I don't want to protect inefficient people by not being open with everyone. Yet I've seen so many amazing technologies created in interesting ways just by giving people freedom to take apart code and put it back together. I'm interested in hearing people's thoughts(doesn't have to be to my specific situation, I'm looking for the general lessons). Its a very stressful decision(but one I feel I must make) because if we go the open source route then there will be no going back. So what are your thoughts? Does open sourcing apply generally or is it only really applicable to software? Is it overall good for people in the industry and outside? I'm actually more interested in the negativeness effects(although positive are welcomed as well) Update: Long story short, although code is involved this is not so much about code as it is more about the idea of open sourcing. We are a mid sized quant hedge fund. We have some unique strategies but also have the standard long/short, arbitrage, global macro, etc.. funds. We are keeping the unique funds we have but the other stuff that everyone else has we are considering open sourcing (We have put in years of work & millions of dollars into. Our funds is pretty popular and our performance is either in first or second quartile so I suspect there will be interest but I don't know to what extent). The goal is not to get a community to work for us or anything, the goal is to let anyone who wants to tinker with it do so and create anything they want (it will not be part of our product line although I may unofficially allocate some our of staff's time to assist any community that grows). Although the code base is quite large, the value in this is the industry knowledge and approaches we have acquired (there are many books on artificial intelligence and quant trading but they are often years behind what's really going on as most firms forbid their staff from discussing what they are doing). We are also considering after we move our clients out to let the software still run and output the resulting portfolios for free as well so people can at least see the results(as long as we have avail. infrastructure). I think our main choices are, we can continue to fight for market share in a products that are becoming commoditized, we can shut the funds/products down(and keep the code but no one outside of our firm will ever learn from it) or we can open source it and let people do what they want. By open sourcing it, my idea is that the talent pool in the industry will grow because right now most of our hires have the same background (CFA, MBA, similar school, same experience,etc.. because we can't spend time training people so the industry 'standardizes' most people and thus the firms themselves start to look/act similar) but this may allow us to identify talent that has never been in the industry before (if we put a GPU license then as people learn from what we did, we can learn from what they do as well and maybe apply it to other areas of our firm). I see a lot of benefits but not many negatives while my peers at the company see the opposite.

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• Trying to install mysql then lots of brew doctor errors

  - by gdi2290

  I couldn't install mysql I get this brew install mysql Error: You must `brew link cmake' before mysql can be installed so then I type brew ink cmake Linking /usr/local/Cellar/cmake/2.8.8... Error: Could not symlink file: /usr/local/Cellar/cmake/2.8.8/share/doc/cmake /usr/local/share/doc is not writable. You should change its permissions. when I typed brew doctor I get this Error: Some directories in /usr/local/share/locale aren't writable. This can happen if you "sudo make install" software that isn't managed by Homebrew. If a brew tries to add locale information to one of these directories, then the install will fail during the link step. You should probably chown them: /usr/local/share/locale/ar /usr/local/share/locale/ar/LC_MESSAGES /usr/local/share/locale/be /usr/local/share/locale/be/LC_MESSAGES /usr/local/share/locale/bg /usr/local/share/locale/bg/LC_MESSAGES /usr/local/share/locale/bs /usr/local/share/locale/bs/LC_MESSAGES /usr/local/share/locale/ca /usr/local/share/locale/ca/LC_MESSAGES /usr/local/share/locale/cs /usr/local/share/locale/cs/LC_MESSAGES /usr/local/share/locale/da /usr/local/share/locale/da/LC_MESSAGES /usr/local/share/locale/de /usr/local/share/locale/de/LC_MESSAGES /usr/local/share/locale/de_AT /usr/local/share/locale/de_AT/LC_MESSAGES /usr/local/share/locale/de_CH /usr/local/share/locale/de_CH/LC_MESSAGES /usr/local/share/locale/de_DE /usr/local/share/locale/de_DE/LC_MESSAGES /usr/local/share/locale/el /usr/local/share/locale/el/LC_MESSAGES /usr/local/share/locale/en_AU /usr/local/share/locale/en_AU/LC_MESSAGES /usr/local/share/locale/en_CA /usr/local/share/locale/en_CA/LC_MESSAGES /usr/local/share/locale/en_GB /usr/local/share/locale/en_GB/LC_MESSAGES /usr/local/share/locale/eo /usr/local/share/locale/eo/LC_MESSAGES /usr/local/share/locale/es /usr/local/share/locale/es/LC_MESSAGES /usr/local/share/locale/es_ES /usr/local/share/locale/es_ES/LC_MESSAGES /usr/local/share/locale/es_PE /usr/local/share/locale/es_PE/LC_MESSAGES /usr/local/share/locale/et /usr/local/share/locale/et/LC_MESSAGES /usr/local/share/locale/fi /usr/local/share/locale/fi/LC_MESSAGES /usr/local/share/locale/fr /usr/local/share/locale/fr/LC_MESSAGES /usr/local/share/locale/fr_FR /usr/local/share/locale/fr_FR/LC_MESSAGES /usr/local/share/locale/gl /usr/local/share/locale/gl/LC_MESSAGES /usr/local/share/locale/he /usr/local/share/locale/he/LC_MESSAGES /usr/local/share/locale/hi /usr/local/share/locale/hi/LC_MESSAGES /usr/local/share/locale/hr /usr/local/share/locale/hr/LC_MESSAGES /usr/local/share/locale/hu /usr/local/share/locale/hu/LC_MESSAGES /usr/local/share/locale/hu_HU /usr/local/share/locale/hu_HU/LC_MESSAGES /usr/local/share/locale/id /usr/local/share/locale/id/LC_MESSAGES /usr/local/share/locale/it /usr/local/share/locale/it/LC_MESSAGES /usr/local/share/locale/ja /usr/local/share/locale/ja/LC_MESSAGES /usr/local/share/locale/ka /usr/local/share/locale/ka/LC_MESSAGES /usr/local/share/locale/ko /usr/local/share/locale/ko/LC_MESSAGES /usr/local/share/locale/lv /usr/local/share/locale/lv/LC_MESSAGES /usr/local/share/locale/mr /usr/local/share/locale/mr/LC_MESSAGES /usr/local/share/locale/nb /usr/local/share/locale/nb/LC_MESSAGES /usr/local/share/locale/nds /usr/local/share/locale/nds/LC_MESSAGES /usr/local/share/locale/nl /usr/local/share/locale/nl/LC_MESSAGES /usr/local/share/locale/nn /usr/local/share/locale/nn/LC_MESSAGES /usr/local/share/locale/oc /usr/local/share/locale/oc/LC_MESSAGES /usr/local/share/locale/pl /usr/local/share/locale/pl/LC_MESSAGES /usr/local/share/locale/pt /usr/local/share/locale/pt/LC_MESSAGES /usr/local/share/locale/pt_BR /usr/local/share/locale/pt_BR/LC_MESSAGES /usr/local/share/locale/pt_PT /usr/local/share/locale/pt_PT/LC_MESSAGES /usr/local/share/locale/ro /usr/local/share/locale/ro/LC_MESSAGES /usr/local/share/locale/ru /usr/local/share/locale/ru/LC_MESSAGES /usr/local/share/locale/sk /usr/local/share/locale/sk/LC_MESSAGES /usr/local/share/locale/sr /usr/local/share/locale/sr/LC_MESSAGES /usr/local/share/locale/sv /usr/local/share/locale/sv/LC_MESSAGES /usr/local/share/locale/ta /usr/local/share/locale/ta/LC_MESSAGES /usr/local/share/locale/te /usr/local/share/locale/te/LC_MESSAGES /usr/local/share/locale/tr /usr/local/share/locale/tr/LC_MESSAGES /usr/local/share/locale/uk /usr/local/share/locale/uk/LC_MESSAGES /usr/local/share/locale/vi /usr/local/share/locale/vi/LC_MESSAGES /usr/local/share/locale/zh_CN /usr/local/share/locale/zh_CN/LC_MESSAGES /usr/local/share/locale/zh_HK /usr/local/share/locale/zh_HK/LC_MESSAGES /usr/local/share/locale/zh_TW /usr/local/share/locale/zh_TW/LC_MESSAGES Error: The /usr/local directory is not writable. Even if this directory was writable when you installed Homebrew, other software may change permissions on this directory. Some versions of the "InstantOn" component of Airfoil are known to do this. You should probably change the ownership and permissions of /usr/local back to your user account. Error: "config" scripts exist outside your system or Homebrew directories. ./configure scripts often look for *-config scripts to determine if software packages are installed, and what additional flags to use when compiling and linking. Having additional scripts in your path can confuse software installed via Homebrew if the config script overrides a system or Homebrew provided script of the same name. We found the following "config" scripts: /opt/sm/pkg/active/bin/curl-config /opt/sm/pkg/active/bin/ncurses5-config /opt/sm/pkg/active/bin/ncursesw5-config /opt/sm/pkg/active/bin/pkg-config /opt/sm/pkg/active/bin/xml2-config /opt/sm/pkg/active/bin/xslt-config Error: gettext was detected in your PREFIX. The gettext provided by Homebrew is "keg-only", meaning it does not get linked into your PREFIX by default. If you brew link gettext then a large number of brews that don't otherwise have a depends_on 'gettext' will pick up gettext anyway during the ./configure step. If you have a non-Homebrew provided gettext, other problems will happen especially if it wasn't compiled with the proper architectures. Error: Unbrewed dylibs were found in /usr/local/lib. If you didn't put them there on purpose they could cause problems when building Homebrew formulae, and may need to be deleted. Unexpected dylibs: /usr/local/lib/libboost_filesystem-mt.dylib /usr/local/lib/libboost_serialization-mt.dylib /usr/local/lib/libboost_system-mt.dylib /usr/local/lib/libencfs.6.dylib /usr/local/lib/libintl.8.dylib /usr/local/lib/libmacfuse_i32.2.dylib /usr/local/lib/libmacfuse_i64.2.dylib /usr/local/lib/libosxfuse_i32.2.dylib /usr/local/lib/libosxfuse_i64.2.dylib /usr/local/lib/librlog.5.0.0.dylib Error: Unbrewed .la files were found in /usr/local/lib. If you didn't put them there on purpose they could cause problems when building Homebrew formulae, and may need to be deleted. Unexpected .la files: /usr/local/lib/libosxfuse_i32.la /usr/local/lib/libosxfuse_i64.la Error: Unbrewed .pc files were found in /usr/local/lib/pkgconfig. If you didn't put them there on purpose they could cause problems when building Homebrew formulae, and may need to be deleted. Unexpected .pc files: /usr/local/lib/pkgconfig/osxfuse.pc Error: You have unlinked kegs in your Cellar Leaving kegs unlinked can lead to build-trouble and cause brews that depend on those kegs to fail to run properly once built. cmake Error: Your pkg-config is not checking "/usr/X11/lib/pkgconfig" for packages. Earlier versions of the pkg-config formula did not add this path to the search path, which means that other formula may not be able to find certain dependencies. To resolve this issue, re-brew pkg-config with: brew rm pkg-config && brew install pkg-config Error: You have a non-Homebrew 'pkg-config' in your PATH: /opt/sm/pkg/active/bin/pkg-config ./configure may have problems finding brew-installed packages using this other pkg-config. Error: Your Xcode is configured with an invalid path. You should change it to the correct path. Please note that there is no correct path at this time if you have only installed the Command Line Tools for Xcode. If your Xcode is pre-4.3 or you installed the whole of Xcode 4.3 then one of these is (probably) what you want: sudo xcode-select -switch /Developer sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer DO NOT SET / OR EVERYTHING BREAKS!

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• Python CGI on Amazon AWS EC2 micro-instance -- a how-to!

  - by user595585

  How can you make an EC2 micro instance serve CGI scripts from lighthttpd? For instance Python CGI? Well, it took half a day, but I have gotten Python cgi running on a free Amazon AWS EC2 micro-instance, using the lighttpd server. I think it will help my fellow noobs to put all the steps in one place. Armed with the simple steps below, it will take you only 15 minutes to set things up! My question for the more experienced users reading this is: Are there any security flaws in what I've done? (See file and directory permissions.) Step 1: Start your EC2 instance and ssh into it. [Obviously, you'll need to sign up for Amazon EC2 and save your key pairs to a *.pem file. I won't go over this, as Amazon tells you how to do it.] Sign into your AWS account and start your EC2 instance. The web has tutorials on doing this. Notice that default instance-size that Amazon presents to you is "small." This is not "micro" and so it will cost you money. Be sure to manually choose "micro." (Micro instances are free only for the first year...) Find the public DNS code for your running instance. To do this, click on the instance in the top pane of the dashboard and you'll eventually see the "Public DNS" field populated in the bottom pane. (You may need to fiddle a bit.) The Public DNS looks something like: ec2-174-129-110-23.compute-1.amazonaws.com Start your Unix console program. (On Max OS X, it's called Terminal, and lives in the Applications - Utilities folder.) cd to the directory on your desktop system that has your *.pem file containing your AWS keypairs. ssh to your EC2 instance using a command like: ssh -i <<your *.pem filename>> ec2-user@<< Public DNS address >> So, for me, this was: ssh -i amzn_ec2_keypair.pem [email protected] Your EC2 instance should let you in. Step 2: Download lighttpd to your EC2 instance. To install lighttpd, you will need root access on your EC2 instance. The problem is: Amazon will not let you sign in as root. (Not straightforwardly, at least.) But there is a workaround. Type this command: sudo /bin/bash The system prompt-character will change from $ to #. We won't exit from "sudo" until the very last step in this whole process. Install the lighttpd application (version 1.4.28-1.3.amzn1 for me): yum install lighttpd Install the FastCGI libraries for lighttpd (not needed, but why not?): yum install lighttpd-fastcgi Test that your server is working: /etc/init.d/lighttpd start Step 3: Let the outside world see your server. If you now tried to hit your server from the browser on your desktop, it would fail. The reason: By default, Amazon AWS does not open any ports to your EC2 instance. So, you have to open the ports manually. Go to your EC2 dashboard in your desktop's browser. Click on "Security Groups" in the left pane. One or more security groups will appear in the upper right pane. Choose the one that was assigned to your EC2 instance when you launched your instance. A table called "Allowed Connections" will appear in the lower right pane. A pop-up menu will let you choose "HTTP" as the connection method. The other values in that line of the table should be: tcp, 80, 80, 0.0.0.0/0 Now hit your EC2 instance's server from the desktop in your browser. Use the Public DNS address that you used earlier to SSH in. You should see the lighttpd generic web page. If you don't, I can't help you because I am such a noob. :-( Step 4: Configure lighttpd to serve CGI. Back in the console program, cd to the configuration directory for lighttpd: cd /etc/lighttpd To enable CGI, you want to uncomment one line in the < modules.conf file. (I could have enabled Fast CGI, but baby steps are best!) You can do this with the "ed" editor as follows: ed modules.conf /include "conf.d\/cgi.conf"/ s/#// w q Create the directory where CGI programs will live. (The /etc/lighttpd/lighttpd.conf file determines where this will be.) We'll create our directory in the default location, so we don't have to do any editing of configuration files: cd /var/www/lighttpd mkdir cgi-bin chmod 755 cgi-bin Almost there! Of course you need to put a test CGI program into the cgi-bin directory. Here is one: cd cgi-bin ed a #!/usr/bin/python print "Content-type: text/html\n\n" print "<html><body>Hello, pyworld.</body></html>" . w hellopyworld.py q chmod 655 hellopyworld.py Restart your lighttpd server: /etc/init.d/lighttpd restart Test your CGI program. In your desktop's browser, hit this URL, substituting your EC2 instance's public DNS address: http://<<Public DNS>>/cgi-bin/hellopyworld.py For me, this was: http://ec2-174-129-110-23.compute-1.amazonaws.com/cgi-bin/hellopyworld.py Step 5: That's it! Clean up, and give thanks! To exit from the "sudo /bin/bash" command given earlier, type: exit Acknowledgements: Heaps of thanks to: wiki.vpslink.com/Install_and_Configure_lighttpd www.cyberciti.biz/tips/lighttpd-howto-setup-cgi-bin-access-for-perl-programs.html aws.typepad.com/aws/2010/06/building-three-tier-architectures-with-security-groups.html Good luck, amigos! I apologize for the non-traditional nature of this "question" but I have gotten so much help from Stackoverflow that I was eager to give something back.

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• tmux: Suddenly, cannot horizontally split

  - by A__A__0

  As root, using a reasonably default .profile and .shrc and an empty tmux.conf, I am unable to split the window horizontally. There are a number of cases to consider so I'll list them clearly. Using the keybinding + empty configuration: nothing happens Using the keybinding + my configuration: a bell is generated, nothing else; occasionally, the split will appear and disappear immediately (maybe it always does this, but I'm connecting over ssh so it may not make it through) Using tmux split-window -h with any config: tmux immediately exits I've posted here in order the server and client verbose logs generated by tmux -v during the third case: server started, pid 9523 socket path /tmp/tmux-0/default new client 7 got 100 from client 7 got 101 from client 7 got 102 from client 7 got 103 from client 7 got 104 from client 7 got 105 from client 7 got 105 from client 7 got 105 from client 7 got 105 from client 7 got 105 from client 7 got 105 from client 7 got 105 from client 7 got 105 from client 7 got 105 from client 7 got 105 from client 7 got 105 from client 7 got 105 from client 7 got 105 from client 7 got 105 from client 7 got 105 from client 7 got 105 from client 7 got 106 from client 7 got 200 from client 7 cmdq 0x801c6e080: new-session (client 7) new term: xterm xterm override: XT xterm override: Ms ]52;%p1%s;%p2%s xterm override: Cs ]12;%p1%s xterm override: Cr ]112 xterm override: Ss [%p1%d q xterm override: Se [2 q new key Oo: 0x1021 (KP/) new key Oj: 0x1022 (KP*) new key Om: 0x1023 (KP-) new key Ow: 0x1024 (KP7) new key Ox: 0x1025 (KP8) new key Oy: 0x1026 (KP9) new key Ok: 0x1027 (KP+) new key Ot: 0x1028 (KP4) new key Ou: 0x1029 (KP5) new key Ov: 0x102a (KP6) new key Oq: 0x102b (KP1) new key Or: 0x102c (KP2) new key Os: 0x102d (KP3) new key OM: 0x102e (KPEnter) new key Op: 0x102f (KP0) new key On: 0x1030 (KP.) new key OA: 0x101d (Up) new key OB: 0x101e (Down) new key OC: 0x1020 (Right) new key OD: 0x101f (Left) new key [A: 0x101d (Up) new key [B: 0x101e (Down) new key [C: 0x1020 (Right) new key [D: 0x101f (Left) new key OH: 0x1018 (Home) new key OF: 0x1019 (End) new key [H: 0x1018 (Home) new key [F: 0x1019 (End) new key Oa: 0x501d (C-Up) new key Ob: 0x501e (C-Down) new key Oc: 0x5020 (C-Right) new key Od: 0x501f (C-Left) new key [a: 0x901d (S-Up) new key [b: 0x901e (S-Down) new key [c: 0x9020 (S-Right) new key [d: 0x901f (S-Left) new key [11^: 0x5002 (C-F1) new key [12^: 0x5003 (C-F2) new key [13^: 0x5004 (C-F3) new key [14^: 0x5005 (C-F4) new key [15^: 0x5006 (C-F5) new key [17^: 0x5007 (C-F6) new key [18^: 0x5008 (C-F7) new key [19^: 0x5009 (C-F8) new key [20^: 0x500a (C-F9) new key [21^: 0x500b (C-F10) new key [23^: 0x500c (C-F11) new key [24^: 0x500d (C-F12) new key [25^: 0x500e (C-F13) new key [26^: 0x500f (C-F14) new key [28^: 0x5010 (C-F15) new key [29^: 0x5011 (C-F16) new key [31^: 0x5012 (C-F17) new key [32^: 0x5013 (C-F18) new key [33^: 0x5014 (C-F19) new key [34^: 0x5015 (C-F20) new key [2^: 0x5016 (C-IC) new key [3^: 0x5017 (C-DC) new key [7^: 0x5018 (C-Home) new key [8^: 0x5019 (C-End) new key [6^: 0x501a (C-NPage) new key [5^: 0x501b (C-PPage) new key [11$: 0x9002 (S-F1) new key [12$: 0x9003 (S-F2) new key [13$: 0x9004 (S-F3) new key [14$: 0x9005 (S-F4) new key [15$: 0x9006 (S-F5) new key [17$: 0x9007 (S-F6) new key [18$: 0x9008 (S-F7) new key [19$: 0x9009 (S-F8) new key [20$: 0x900a (S-F9) new key [21$: 0x900b (S-F10) new key [23$: 0x900c (S-F11) new key [24$: 0x900d (S-F12) new key [25$: 0x900e (S-F13) new key [26$: 0x900f (S-F14) new key [28$: 0x9010 (S-F15) new key [29$: 0x9011 (S-F16) new key [31$: 0x9012 (S-F17) new key [32$: 0x9013 (S-F18) new key [33$: 0x9014 (S-F19) new key [34$: 0x9015 (S-F20) new key [2$: 0x9016 (S-IC) new key [3$: 0x9017 (S-DC) new key [7$: 0x9018 (S-Home) new key [8$: 0x9019 (S-End) new key [6$: 0x901a (S-NPage) new key [5$: 0x901b (S-PPage) new key [11@: 0xd002 (C-S-F1) new key [12@: 0xd003 (C-S-F2) new key [13@: 0xd004 (C-S-F3) new key [14@: 0xd005 (C-S-F4) new key [15@: 0xd006 (C-S-F5) new key [17@: 0xd007 (C-S-F6) new key [18@: 0xd008 (C-S-F7) new key [19@: 0xd009 (C-S-F8) new key [20@: 0xd00a (C-S-F9) new key [21@: 0xd00b (C-S-F10) new key [23@: 0xd00c (C-S-F11) new key [24@: 0xd00d (C-S-F12) new key [25@: 0xd00e (C-S-F13) new key [26@: 0xd00f (C-S-F14) new key [28@: 0xd010 (C-S-F15) new key [29@: 0xd011 (C-S-F16) new key [31@: 0xd012 (C-S-F17) new key [32@: 0xd013 (C-S-F18) new key [33@: 0xd014 (C-S-F19) new key [34@: 0xd015 (C-S-F20) new key [2@: 0xd016 (C-S-IC) new key [3@: 0xd017 (C-S-DC) new key [7@: 0xd018 (C-S-Home) new key [8@: 0xd019 (C-S-End) new key [6@: 0xd01a (C-S-NPage) new key [5@: 0xd01b (C-S-PPage) new key [I: 0x1031 ((null)) new key [O: 0x1032 ((null)) new key OP: 0x1002 (F1) new key OQ: 0x1003 (F2) new key OR: 0x1004 (F3) new key OS: 0x1005 (F4) new key [15~: 0x1006 (F5) new key [17~: 0x1007 (F6) new key [18~: 0x1008 (F7) new key [19~: 0x1009 (F8) new key [20~: 0x100a (F9) new key [21~: 0x100b (F10) new key [23~: 0x100c (F11) new key [24~: 0x100d (F12) new key [2~: 0x1016 (IC) new key [3~: 0x1017 (DC) replacing key OH: 0x1018 (Home) replacing key OF: 0x1019 (End) new key [6~: 0x101a (NPage) new key [5~: 0x101b (PPage) new key [Z: 0x101c (BTab) replacing key OA: 0x101d (Up) replacing key OB: 0x101e (Down) replacing key OD: 0x101f (Left) replacing key OC: 0x1020 (Right) spawn: /bin/sh -- session 0 created writing 207 to client 7 got 208 from client 7 input_parse: '#' ground input_parse: ' ' ground keys are 7 ([?1;2c) received service class 1 complete key [?1;2c 0xfff keys are 1 (t) complete key t 0x74 input_parse: 't' ground keys are 1 (m) complete key m 0x6d input_parse: 'm' ground keys are 1 (u) complete key u 0x75 input_parse: 'u' ground keys are 1 (x) complete key x 0x78 input_parse: 'x' ground keys are 1 ( ) complete key 0x20 input_parse: ' ' ground keys are 1 (s) complete key s 0x73 input_parse: 's' ground keys are 1 (p) complete key p 0x70 input_parse: 'p' ground keys are 1 (l) complete key l 0x6c input_parse: 'l' ground keys are 1 (i) complete key i 0x69 input_parse: 'i' ground keys are 1 (t) complete key t 0x74 input_parse: 't' ground keys are 1 (-) complete key - 0x2d input_parse: '-' ground keys are 1 (d) complete key d 0x64 input_parse: 'd' ground keys are 1 () complete key 0x7f input_parse: '' ground input_c0_dispatch: ' input_parse: '' ground input_parse: '[' esc_enter input_parse: 'K' csi_enter input_csi_dispatch: 'K' "" "" keys are 1 (w) complete key w 0x77 input_parse: 'w' ground keys are 1 (i) complete key i 0x69 input_parse: 'i' ground keys are 1 (n) complete key n 0x6e input_parse: 'n' ground keys are 1 (d) complete key d 0x64 input_parse: 'd' ground keys are 1 (o) complete key o 0x6f input_parse: 'o' ground keys are 1 (w) complete key w 0x77 input_parse: 'w' ground keys are 1 ( ) complete key 0x20 input_parse: ' ' ground keys are 1 (-) complete key - 0x2d input_parse: '-' ground keys are 1 (h) complete key h 0x68 input_parse: 'h' ground keys are 1 ( ) complete key 0xd input_parse: ' ' ground input_c0_dispatch: ' input_parse: ' ' ground input_c0_dispatch: ' new client 13 got 100 from client 13 got 101 from client 13 got 102 from client 13 got 103 from client 13 got 104 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 105 from client 13 got 106 from client 13 got 200 from client 13 cmdq 0x801c6e160: split-window -h (client 13) spawn: /bin/sh -- writing 203 to client 13 input_parse: '#' ground input_parse: ' ' ground input_parse: '#' ground input_parse: ' ' ground lost client 13 session 0 destroyed writing 203 to client 7 got 205 from client 7 writing 204 to client 7 lost client 7 got 207 from server got 203 from server got 204 from server There are some other peculiarities: With a newly created user (from which I overwrote root's .profile and .shrc, tmux works perfectly. Occasionally (twice out of the 50 or so times I've tested it), the splitting will work fine once in a session. (This happened for example when I ran ktrace on tmux, which I can also post) To explain the 'suddenly' part of the title: when I started my newly updated mysql56-server, tmux immediately exited and lost the session. Recently I changed architectures, from FreeBSD 10.0 i386 to amd64, and I am still working through shared library incompatibilities. I suspect that this could be involved, but I can't imagine how an incompatibility of this sort could result in such a specific, isolated failure.

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• PTLQueue : a scalable bounded-capacity MPMC queue

  - by Dave

  Title: Fast concurrent MPMC queue -- I've used the following concurrent queue algorithm enough that it warrants a blog entry. I'll sketch out the design of a fast and scalable multiple-producer multiple-consumer (MPSC) concurrent queue called PTLQueue. The queue has bounded capacity and is implemented via a circular array. Bounded capacity can be a useful property if there's a mismatch between producer rates and consumer rates where an unbounded queue might otherwise result in excessive memory consumption by virtue of the container nodes that -- in some queue implementations -- are used to hold values. A bounded-capacity queue can provide flow control between components. Beware, however, that bounded collections can also result in resource deadlock if abused. The put() and take() operators are partial and wait for the collection to become non-full or non-empty, respectively. Put() and take() do not allocate memory, and are not vulnerable to the ABA pathologies. The PTLQueue algorithm can be implemented equally well in C/C++ and Java. Partial operators are often more convenient than total methods. In many use cases if the preconditions aren't met, there's nothing else useful the thread can do, so it may as well wait via a partial method. An exception is in the case of work-stealing queues where a thief might scan a set of queues from which it could potentially steal. Total methods return ASAP with a success-failure indication. (It's tempting to describe a queue or API as blocking or non-blocking instead of partial or total, but non-blocking is already an overloaded concurrency term. Perhaps waiting/non-waiting or patient/impatient might be better terms). It's also trivial to construct partial operators by busy-waiting via total operators, but such constructs may be less efficient than an operator explicitly and intentionally designed to wait. A PTLQueue instance contains an array of slots, where each slot has volatile Turn and MailBox fields. The array has power-of-two length allowing mod/div operations to be replaced by masking. We assume sensible padding and alignment to reduce the impact of false sharing. (On x86 I recommend 128-byte alignment and padding because of the adjacent-sector prefetch facility). Each queue also has PutCursor and TakeCursor cursor variables, each of which should be sequestered as the sole occupant of a cache line or sector. You can opt to use 64-bit integers if concerned about wrap-around aliasing in the cursor variables. Put(null) is considered illegal, but the caller or implementation can easily check for and convert null to a distinguished non-null proxy value if null happens to be a value you'd like to pass. Take() will accordingly convert the proxy value back to null. An advantage of PTLQueue is that you can use atomic fetch-and-increment for the partial methods. We initialize each slot at index I with (Turn=I, MailBox=null). Both cursors are initially 0. All shared variables are considered "volatile" and atomics such as CAS and AtomicFetchAndIncrement are presumed to have bidirectional fence semantics. Finally T is the templated type. I've sketched out a total tryTake() method below that allows the caller to poll the queue. tryPut() has an analogous construction. Zebra stripping : alternating row colors for nice-looking code listings. See also google code "prettify" : https://code.google.com/p/google-code-prettify/ Prettify is a javascript module that yields the HTML/CSS/JS equivalent of pretty-print. -- pre:nth-child(odd) { background-color:#ff0000; } pre:nth-child(even) { background-color:#0000ff; } border-left: 11px solid #ccc; margin: 1.7em 0 1.7em 0.3em; background-color:#BFB; font-size:12px; line-height:65%; " // PTLQueue : Put(v) : // producer : partial method - waits as necessary assert v != null assert Mask = 1 && (Mask & (Mask+1)) == 0 // Document invariants // doorway step // Obtain a sequence number -- ticket // As a practical concern the ticket value is temporally unique // The ticket also identifies and selects a slot auto tkt = AtomicFetchIncrement (&PutCursor, 1) slot * s = &Slots[tkt & Mask] // waiting phase : // wait for slot's generation to match the tkt value assigned to this put() invocation. // The "generation" is implicitly encoded as the upper bits in the cursor // above those used to specify the index : tkt div (Mask+1) // The generation serves as an epoch number to identify a cohort of threads // accessing disjoint slots while s-Turn != tkt : Pause assert s-MailBox == null s-MailBox = v // deposit and pass message Take() : // consumer : partial method - waits as necessary auto tkt = AtomicFetchIncrement (&TakeCursor,1) slot * s = &Slots[tkt & Mask] // 2-stage waiting : // First wait for turn for our generation // Acquire exclusive "take" access to slot's MailBox field // Then wait for the slot to become occupied while s-Turn != tkt : Pause // Concurrency in this section of code is now reduced to just 1 producer thread // vs 1 consumer thread. // For a given queue and slot, there will be most one Take() operation running // in this section. // Consumer waits for producer to arrive and make slot non-empty // Extract message; clear mailbox; advance Turn indicator // We have an obvious happens-before relation : // Put(m) happens-before corresponding Take() that returns that same "m" for T v = s-MailBox if v != null : s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 // unlock slot to admit next producer and consumer return v Pause tryTake() : // total method - returns ASAP with failure indication for auto tkt = TakeCursor slot * s = &Slots[tkt & Mask] if s-Turn != tkt : return null T v = s-MailBox // presumptive return value if v == null : return null // ratify tkt and v values and commit by advancing cursor if CAS (&TakeCursor, tkt, tkt+1) != tkt : continue s-MailBox = null ST-ST barrier s-Turn = tkt + Mask + 1 return v The basic idea derives from the Partitioned Ticket Lock "PTL" (US20120240126-A1) and the MultiLane Concurrent Bag (US8689237). The latter is essentially a circular ring-buffer where the elements themselves are queues or concurrent collections. You can think of the PTLQueue as a partitioned ticket lock "PTL" augmented to pass values from lock to unlock via the slots. Alternatively, you could conceptualize of PTLQueue as a degenerate MultiLane bag where each slot or "lane" consists of a simple single-word MailBox instead of a general queue. Each lane in PTLQueue also has a private Turn field which acts like the Turn (Grant) variables found in PTL. Turn enforces strict FIFO ordering and restricts concurrency on the slot mailbox field to at most one simultaneous put() and take() operation. PTL uses a single "ticket" variable and per-slot Turn (grant) fields while MultiLane has distinct PutCursor and TakeCursor cursors and abstract per-slot sub-queues. Both PTL and MultiLane advance their cursor and ticket variables with atomic fetch-and-increment. PTLQueue borrows from both PTL and MultiLane and has distinct put and take cursors and per-slot Turn fields. Instead of a per-slot queues, PTLQueue uses a simple single-word MailBox field. PutCursor and TakeCursor act like a pair of ticket locks, conferring "put" and "take" access to a given slot. PutCursor, for instance, assigns an incoming put() request to a slot and serves as a PTL "Ticket" to acquire "put" permission to that slot's MailBox field. To better explain the operation of PTLQueue we deconstruct the operation of put() and take() as follows. Put() first increments PutCursor obtaining a new unique ticket. That ticket value also identifies a slot. Put() next waits for that slot's Turn field to match that ticket value. This is tantamount to using a PTL to acquire "put" permission on the slot's MailBox field. Finally, having obtained exclusive "put" permission on the slot, put() stores the message value into the slot's MailBox. Take() similarly advances TakeCursor, identifying a slot, and then acquires and secures "take" permission on a slot by waiting for Turn. Take() then waits for the slot's MailBox to become non-empty, extracts the message, and clears MailBox. Finally, take() advances the slot's Turn field, which releases both "put" and "take" access to the slot's MailBox. Note the asymmetry : put() acquires "put" access to the slot, but take() releases that lock. At any given time, for a given slot in a PTLQueue, at most one thread has "put" access and at most one thread has "take" access. This restricts concurrency from general MPMC to 1-vs-1. We have 2 ticket locks -- one for put() and one for take() -- each with its own "ticket" variable in the form of the corresponding cursor, but they share a single "Grant" egress variable in the form of the slot's Turn variable. Advancing the PutCursor, for instance, serves two purposes. First, we obtain a unique ticket which identifies a slot. Second, incrementing the cursor is the doorway protocol step to acquire the per-slot mutual exclusion "put" lock. The cursors and operations to increment those cursors serve double-duty : slot-selection and ticket assignment for locking the slot's MailBox field. At any given time a slot MailBox field can be in one of the following states: empty with no pending operations -- neutral state; empty with one or more waiting take() operations pending -- deficit; occupied with no pending operations; occupied with one or more waiting put() operations -- surplus; empty with a pending put() or pending put() and take() operations -- transitional; or occupied with a pending take() or pending put() and take() operations -- transitional. The partial put() and take() operators can be implemented with an atomic fetch-and-increment operation, which may confer a performance advantage over a CAS-based loop. In addition we have independent PutCursor and TakeCursor cursors. Critically, a put() operation modifies PutCursor but does not access the TakeCursor and a take() operation modifies the TakeCursor cursor but does not access the PutCursor. This acts to reduce coherence traffic relative to some other queue designs. It's worth noting that slow threads or obstruction in one slot (or "lane") does not impede or obstruct operations in other slots -- this gives us some degree of obstruction isolation. PTLQueue is not lock-free, however. The implementation above is expressed with polite busy-waiting (Pause) but it's trivial to implement per-slot parking and unparking to deschedule waiting threads. It's also easy to convert the queue to a more general deque by replacing the PutCursor and TakeCursor cursors with Left/Front and Right/Back cursors that can move either direction. Specifically, to push and pop from the "left" side of the deque we would decrement and increment the Left cursor, respectively, and to push and pop from the "right" side of the deque we would increment and decrement the Right cursor, respectively. We used a variation of PTLQueue for message passing in our recent OPODIS 2013 paper. ul { list-style:none; padding-left:0; padding:0; margin:0; margin-left:0; } ul#myTagID { padding: 0px; margin: 0px; list-style:none; margin-left:0;} -- -- There's quite a bit of related literature in this area. I'll call out a few relevant references: Wilson's NYU Courant Institute UltraComputer dissertation from 1988 is classic and the canonical starting point : Operating System Data Structures for Shared-Memory MIMD Machines with Fetch-and-Add. Regarding provenance and priority, I think PTLQueue or queues effectively equivalent to PTLQueue have been independently rediscovered a number of times. See CB-Queue and BNPBV, below, for instance. But Wilson's dissertation anticipates the basic idea and seems to predate all the others. Gottlieb et al : Basic Techniques for the Efficient Coordination of Very Large Numbers of Cooperating Sequential Processors Orozco et al : CB-Queue in Toward high-throughput algorithms on many-core architectures which appeared in TACO 2012. Meneghin et al : BNPVB family in Performance evaluation of inter-thread communication mechanisms on multicore/multithreaded architecture Dmitry Vyukov : bounded MPMC queue (highly recommended) Alex Otenko : US8607249 (highly related). John Mellor-Crummey : Concurrent queues: Practical fetch-and-phi algorithms. Technical Report 229, Department of Computer Science, University of Rochester Thomasson : FIFO Distributed Bakery Algorithm (very similar to PTLQueue). Scott and Scherer : Dual Data Structures I'll propose an optimization left as an exercise for the reader. Say we wanted to reduce memory usage by eliminating inter-slot padding. Such padding is usually "dark" memory and otherwise unused and wasted. But eliminating the padding leaves us at risk of increased false sharing. Furthermore lets say it was usually the case that the PutCursor and TakeCursor were numerically close to each other. (That's true in some use cases). We might still reduce false sharing by incrementing the cursors by some value other than 1 that is not trivially small and is coprime with the number of slots. Alternatively, we might increment the cursor by one and mask as usual, resulting in a logical index. We then use that logical index value to index into a permutation table, yielding an effective index for use in the slot array. The permutation table would be constructed so that nearby logical indices would map to more distant effective indices. (Open question: what should that permutation look like? Possibly some perversion of a Gray code or De Bruijn sequence might be suitable). As an aside, say we need to busy-wait for some condition as follows : "while C == 0 : Pause". Lets say that C is usually non-zero, so we typically don't wait. But when C happens to be 0 we'll have to spin for some period, possibly brief. We can arrange for the code to be more machine-friendly with respect to the branch predictors by transforming the loop into : "if C == 0 : for { Pause; if C != 0 : break; }". Critically, we want to restructure the loop so there's one branch that controls entry and another that controls loop exit. A concern is that your compiler or JIT might be clever enough to transform this back to "while C == 0 : Pause". You can sometimes avoid this by inserting a call to a some type of very cheap "opaque" method that the compiler can't elide or reorder. On Solaris, for instance, you could use :"if C == 0 : { gethrtime(); for { Pause; if C != 0 : break; }}". It's worth noting the obvious duality between locks and queues. If you have strict FIFO lock implementation with local spinning and succession by direct handoff such as MCS or CLH,then you can usually transform that lock into a queue. Hidden commentary and annotations - invisible : * And of course there's a well-known duality between queues and locks, but I'll leave that topic for another blog post. * Compare and contrast : PTLQ vs PTL and MultiLane * Equivalent : Turn; seq; sequence; pos; position; ticket * Put = Lock; Deposit Take = identify and reserve slot; wait; extract & clear; unlock * conceptualize : Distinct PutLock and TakeLock implemented as ticket lock or PTL Distinct arrival cursors but share per-slot "Turn" variable provides exclusive role-based access to slot's mailbox field put() acquires exclusive access to a slot for purposes of "deposit" assigns slot round-robin and then acquires deposit access rights/perms to that slot take() acquires exclusive access to slot for purposes of "withdrawal" assigns slot round-robin and then acquires withdrawal access rights/perms to that slot At any given time, only one thread can have withdrawal access to a slot at any given time, only one thread can have deposit access to a slot Permissible for T1 to have deposit access and T2 to simultaneously have withdrawal access * round-robin for the purposes of; role-based; access mode; access role mailslot; mailbox; allocate/assign/identify slot rights; permission; license; access permission; * PTL/Ticket hybrid Asymmetric usage ; owner oblivious lock-unlock pairing K-exclusion add Grant cursor pass message m from lock to unlock via Slots[] array Cursor performs 2 functions : + PTL ticket + Assigns request to slot in round-robin fashion Deconstruct protocol : explication put() : allocate slot in round-robin fashion acquire PTL for "put" access store message into slot associated with PTL index take() : Acquire PTL for "take" access // doorway step seq = fetchAdd (&Grant, 1) s = &Slots[seq & Mask] // waiting phase while s-Turn != seq : pause Extract : wait for s-mailbox to be full v = s-mailbox s-mailbox = null Release PTL for both "put" and "take" access s-Turn = seq + Mask + 1 * Slot round-robin assignment and lock "doorway" protocol leverage the same cursor and FetchAdd operation on that cursor FetchAdd (&Cursor,1) + round-robin slot assignment and dispersal + PTL/ticket lock "doorway" step waiting phase is via "Turn" field in slot * PTLQueue uses 2 cursors -- put and take. Acquire "put" access to slot via PTL-like lock Acquire "take" access to slot via PTL-like lock 2 locks : put and take -- at most one thread can access slot's mailbox Both locks use same "turn" field Like multilane : 2 cursors : put and take slot is simple 1-capacity mailbox instead of queue Borrow per-slot turn/grant from PTL Provides strict FIFO Lock slot : put-vs-put take-vs-take at most one put accesses slot at any one time at most one put accesses take at any one time reduction to 1-vs-1 instead of N-vs-M concurrency Per slot locks for put/take Release put/take by advancing turn * is instrumental in ... * P-V Semaphore vs lock vs K-exclusion * See also : FastQueues-excerpt.java dice-etc/queue-mpmc-bounded-blocking-circular-xadd/ * PTLQueue is the same as PTLQB - identical * Expedient return; ASAP; prompt; immediately * Lamport's Bakery algorithm : doorway step then waiting phase Threads arriving at doorway obtain a unique ticket number Threads enter in ticket order * In the terminology of Reed and Kanodia a ticket lock corresponds to the busy-wait implementation of a semaphore using an eventcount and a sequencer It can also be thought of as an optimization of Lamport's bakery lock was designed for fault-tolerance rather than performance Instead of spinning on the release counter, processors using a bakery lock repeatedly examine the tickets of their peers --

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• cannt run phpunit tests on bash ubuntu 11.10

  - by Mohamad Elbialy

  i'm working with ubuntu 11.10 as root on my local machine, i've installed xampp 1.7.7 and i'm a newbie to ubuntu, while following a tutorial on sitepoint(http://www.sitepoint.com/getting-started-with-pear/) on how to install pear to use PhpUnit, i didnt notice it then, but it seems that i installed or used an existing php version 5.3.6 in CL to do that, also the pear installation was built on this version, while xampp being installed,i now have two versions of php,xampp's 5.3.8 and the 5.3.6, anyway, what i want to do is to use the existing xampp php version and build pear on that, to make all my work through xampp.so my questions are: how to uninstall the php V5.3.6 and it's pear installation? how to link the CL with the php ver. of xampp? how to build the next pear installation on the php ver. of xampp? i want all my web dev. work through xampp, is there anything else i need to unistall, to avoid this confusion? 4. i did the following in attampet to solve the problem: i wrote this in bash: gedit ~/.bashrc i added that to the end of ~/.bashrc file in attempt to change environment path: export PATH=/opt/lampp/bin:$PATH export PATH=/opt/lampp/lib/php:$PATH export PATH=/opt/lampp/lib/php/PHPUnit/pearcmd.php:$PATH i checked the php and pear version using 'php -v' and 'pear list' i got an ouput of: PHP 5.3.8 (cli) (built: Sep 19 2011 13:29:27) Copyright (c) 1997-2011 The PHP Group Zend Engine v2.3.0, Copyright (c) 1998-2011 Zend Technologies and for pear: Installed packages, channel pear.php.net: ========================================= Package Version State Archive_Tar 1.3.9 stable Console_Getopt 1.3.1 stable PEAR 1.9.4 stable PHPUnit 1.3.2 stable Structures_Graph 1.0.4 stable XML_Util 1.2.1 stable when i run: 'phpunit MessageTest.php': i get PHP Warning: require_once(PHP/CodeCoverage/Filter.php): failed to open stream: No such file or directory in /usr/bin/phpunit on line 38 Warning: require_once(PHP/CodeCoverage/Filter.php): failed to open stream: No such file or directory in /usr/bin/phpunit on line 38 PHP Fatal error: require_once(): Failed opening required 'PHP/CodeCoverage/Filter.php' (include_path='.:/php/includes:/opt/lampp/lib/php:/opt/lampp/bin:/opt/lampp/lib/php/PEAR') in /usr/bin/phpunit on line 38 5.i ran the following commands as reported in other questions as a solution to that error: sudo apt-get remove phpunit sudo pear channel-discover pear.phpunit.de sudo pear channel-discover pear.symfony-project.com sudo pear channel-discover components.ez.no sudo pear update-channels sudo pear upgrade-all sudo pear install --alldeps phpunit/PHPUnit sudo apt-get install phpunit and updated include path of php.ini to be: include_path = ".:/php/includes:/opt/lampp/lib/php:/opt/lampp/bin:/opt/lampp/lib/php/PEAR" the php file MessageTest.php: <?php require 'PHPUnit/Autoload.php'; $path = '/opt/lampp/lib/php/PEAR'; set_include_path(get_include_path() . PATH_SEPARATOR . $path); require_once 'PHPUnit/Framework/TestCase.php'; require_once 'Message/Controller/MessageController.php'; class MessageTest extends PHPUnit_Framework_TestCase{ private $message; public function setUp() { $this->message = new MessageController(); } public function tearDown() { } public function testRepeat(){ $yell = "Hello, Any One Out There?"; $this->message->repeat($yell); //sending a request $returnedMessage = $this->message->repeat($yell);//get a response $this->assertEquals($returnedMessage, $yell); } } ?> MessageController class from MessageController.php that i'm trying to test <?php class MessageController { public function actionHelloWorld() { echo 'helloWorld'; } public function repeat($inputString){ return $inputString; } } $msg = new MessageController; ?> I'm not using any PHP framework, i just made the files and classes sounds like it that's all. and still i get the same error: PHP Warning: require_once(PHP/CodeCoverage/Filter.php): failed to open stream: No such file or directory in /usr/bin/phpunit on line Warning: require_once(PHP/CodeCoverage/Filter.php): failed to open stream: No such file or directory in /usr/bin/phpunit on line 38 PHP Fatal error: require_once(): Failed opening required 'PHP/CodeCoverage/Filter.php' (include_path='.:/php/includes:/opt/lampp/lib/php:/opt/lampp/bin:/opt/lampp/lib/php/PEAR') in /usr/bin/phpunit on line 38 sure, i'm getting demanding here, i've wasted a lot of time and got really frustrated over this, hope you guys dont get bored reading through my questions, i appreciate your help thanks in advance, Mohamad elbialy

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• Network authentication + roaming home directory - which technology should I look into using?

  - by Brian

  I'm looking into software which provides a user with a single identity across multiple computers. That is, a user should have the same permissions on each computer, and the user should have access to all of his or her files (roaming home directory) on each computer. There seem to be many solutions for this general idea, but I'm trying to determine the best one for me. Here are some details along with requirements: The network of machines are Amazon EC2 instances running Ubuntu. We access the machines with SSH. Some machines on this LAN may have different uses, but I am only discussing machines for a certain use (running a multi-tenancy platform). The system will not necessarily have a constant amount of machines. We may have to permanently or temporarily alter the amount of machines running. This is the the reason why I'm looking into centralized authentication/storage. The implementation of this effect should be a secure one. We're unsure if users will have direct shell access, but their software will potentially be running (under restricted Linux user names, of course) on our systems, which is as good as direct shell access. Let's assume that their software could potentially be malicious for the sake of security. I have heard of several technologies/combinations to achieve my goal, but I'm unsure of the ramifications of each. An older ServerFault post recommended NFS & NIS, though the combination has security problems according to this old article by Symantec. The article suggests moving to NIS+, but, as it is old, this Wikipedia article has cited statements suggesting a trending away from NIS+ by Sun. The recommended replacement is another thing I have heard of... LDAP. It looks like LDAP can be used to save user information in a centralized location on a network. NFS would still need to be used to cover the 'roaming home folder' requirement, but I see references of them being used together. Since the Symantec article pointed out security problems in both NIS and NFS, is there software to replace NFS, or should I heed that article's suggestions for locking it down? I'm tending toward LDAP because another fundamental piece of our architecture, RabbitMQ, has a authentication/authorization plugin for LDAP. RabbitMQ will be accessible in a restricted manner to users on the system, so I would like to tie the security systems together if possible. Kerberos is another secure authentication protocol that I have heard of. I learned a bit about it some years ago in a cryptography class but don't remember much about it. I have seen suggestions online that it can be combined with LDAP in several ways. Is this necessary? What are the security risks of LDAP without Kerberos? I also remember Kerberos being used in another piece of software developed by Carnegie Mellon University... Andrew File System, or AFS. OpenAFS is available for use, though its setup seems a bit complicated. At my university, AFS provides both requirements... I can log in to any machine, and my "AFS folder" is always available (at least when I acquire an AFS token). Along with suggestions for which path I should look into, does anybody have any guides which were particularly helpful? As the bold text pointed out, LDAP looks to be the best choice, but I'm particularly interested in the implementation details (Keberos? NFS?) with respect to security.

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• Recommendations for distributed processing/distributed storage systems

  - by Eddie

  At my organization we have a processing and storage system spread across two dozen linux machines that handles over a petabyte of data. The system right now is very ad-hoc; processing automation and data management is handled by a collection of large perl programs on independent machines. I am looking at distributed processing and storage systems to make it easier to maintain, evenly distribute load and data with replication, and grow in disk space and compute power. The system needs to be able to handle millions of files, varying in size between 50 megabytes to 50 gigabytes. Once created, the files will not be appended to, only replaced completely if need be. The files need to be accessible via HTTP for customer download. Right now, processing is automated by perl scripts (that I have complete control over) which call a series of other programs (that I don't have control over because they are closed source) that essentially transforms one data set into another. No data mining happening here. Here is a quick list of things I am looking for: Reliability: These data must be accessible over HTTP about 99% of the time so I need something that does data replication across the cluster. Scalability: I want to be able to add more processing power and storage easily and rebalance the data on across the cluster. Distributed processing: Easy and automatic job scheduling and load balancing that fits with processing workflow I briefly described above. Data location awareness: Not strictly required but desirable. Since data and processing will be on the same set of nodes I would like the job scheduler to schedule jobs on or close to the node that the data is actually on to cut down on network traffic. Here is what I've looked at so far: Storage Management: GlusterFS: Looks really nice and easy to use but doesn't seem to have a way to figure out what node(s) a file actually resides on to supply as a hint to the job scheduler. GPFS: Seems like the gold standard of clustered filesystems. Meets most of my requirements except, like glusterfs, data location awareness. Ceph: Seems way to immature right now. Distributed processing: Sun Grid Engine: I have a lot of experience with this and it's relatively easy to use (once it is configured properly that is). But Oracle got its icy grip around it and it no longer seems very desirable. Both: Hadoop/HDFS: At first glance it looked like hadoop was perfect for my situation. Distributed storage and job scheduling and it was the only thing I found that would give me the data location awareness that I wanted. But I don't like the namename being a single point of failure. Also, I'm not really sure if the MapReduce paradigm fits the type of processing workflow that I have. It seems like you need to write all your software specifically for MapReduce instead of just using Hadoop as a generic job scheduler. OpenStack: I've done some reading on this but I'm having trouble deciding if it fits well with my problem or not. Does anyone have opinions or recommendations for technologies that would fit my problem well? Any suggestions or advise would be greatly appreciated. Thanks!

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• How to set up a centralized backup server with lots of offsite workstations, intermittent internet connectivity, and stubborn users?

  - by Zac B

  This might be an impossible question. Context: We have a bunch of computers across around 1000 users. We have a centralized office where 900 of the users work, most of the time. Most of the computers are laptops. They are very frequently coming on and off the network for hours at a time. Users often take their computers home and do lots of work from home. In addition, there are a handful of users who work elsewhere in the country, who are offline (no internet connection whatsoever) for more than half of the time they use their machines. All of the machines are Windows 7/XP. Problem: People are always losing data. One day someone accidentally deletes a bunch of files. The next day someone else installs a bad driver or tries to mess with something in system32 and needs a personal data backup/reinstall of Windows. Because of how many of our business operations are done without an internet connection, and how frequently computers come on- and offline, it's unfeasible to make users use network storage for all of their data. We tried giving them Dropboxes, and they stored their files elsewhere. We bought and deployed Altiris, and they uninstalled it and blamed us when they couldn't get files back that they accidentally deleted while they were offline and hadn't taken a backup in months. We tried teaching them backup best-practices, and using scheduled sync tools to upload things to the network drives, and they turned them off because they "looked like viruses". It doesn't help that many of these users are pretty high up in the business and are not amicable to any sort of "you need to do something regularly because we say so" solution. Question: Other than finding another job where IT is treated differently and users are willing to follow best practices, how would people recommend I implement a file backup solution that supports the following: Backs up to a centralized server over LAN or WAN whenever a network link becomes available, or on a schedule. Supports interrupted/resumed backups (and hopefully file-delta only backups), since connections to the network (WAN or LAN) are often slow and only open for half an hour or so. Supports relatively rapid, "I accidentally deleted the TPS reports! Oh no!" single-file recovery, ideally administered from the central backup server rather than the client PC. Supports local-to-local file delta backup on a schedule, so that users without a network connection for a few days can still retrieve accidental deletions or whatnot. Ideally, the local stored backups would be pushed up to the server whenever network link is available. Isn't configurable on the clients without certain credentials. Because the CFOs (who won't give up their admin rights on the domain) will disable it if they can. Backs up the entire hard drive. There are people who are self-righteous about storing things in C:\, or in the recycle bin, or in the C:\Windows dir (yes, I know). I'm fine integrating multiple products/solutions, or scripting different programs together myself (I'm a somewhat competent programmer), but I've been drawing a blank on where to start. Dropbox is folder-specific, Altiris doesn't cope with LAN outages or interrupted/resumed backups, Volume Shadow Copy is awesome for a local-to-local solution, but I don't know how to push days of stored shadow copies up to a server in a 2 hour window of network access. The company is fine with spending decent money on this, thousands (USD) on a server, and hundreds on clients, if necessary. I want to emphasize that this isn't a shopping list request. While I wish there was a program out there that did what I want, I've looked pretty hard, and not found anything that fits the bill. Instead, I'm hoping for ideas on where to start hacking things together from scratch/from different technologies to make something stable that works. Cheers!

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• Can't sync filesystem without reboot

  - by Fabio

  I'm having an issue with a linux server. Once a week the running mysql instance hangs and there is no way to fully stop it. If I kill it, it remains in zombie status and init does not reap its pid. The server is used for staging deployments and some internal tools, so it's not under heavy load. The only process constantly used id mysql and for this I think that it's the only process which suffer of this issue. I've searched system logs for errors and the only thing I found is this error (repeated a couple of times) in dmesg output: [706560.640085] INFO: task mysqld:31965 blocked for more than 120 seconds. [706560.640198] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [706560.640312] mysqld D ffff88032fd93f40 0 31965 1 0x00000000 [706560.640317] ffff880242a27d18 0000000000000086 ffff88031a50dd00 ffff880242a27fd8 [706560.640321] ffff880242a27fd8 ffff880242a27fd8 ffff88031e549740 ffff88031a50dd00 [706560.640325] ffff88031a50dd00 ffff88032fd947f8 0000000000000002 ffffffff8112f250 [706560.640328] Call Trace: [706560.640338] [<ffffffff8112f250>] ? __lock_page+0x70/0x70 [706560.640344] [<ffffffff816cb1b9>] schedule+0x29/0x70 [706560.640347] [<ffffffff816cb28f>] io_schedule+0x8f/0xd0 [706560.640350] [<ffffffff8112f25e>] sleep_on_page+0xe/0x20 [706560.640353] [<ffffffff816c9900>] __wait_on_bit+0x60/0x90 [706560.640356] [<ffffffff8112f390>] wait_on_page_bit+0x80/0x90 [706560.640360] [<ffffffff8107dce0>] ? autoremove_wake_function+0x40/0x40 [706560.640363] [<ffffffff8112f891>] filemap_fdatawait_range+0x101/0x190 [706560.640366] [<ffffffff81130975>] filemap_write_and_wait_range+0x65/0x70 [706560.640371] [<ffffffff8122e441>] ext4_sync_file+0x71/0x320 [706560.640376] [<ffffffff811c3e6d>] do_fsync+0x5d/0x90 [706560.640379] [<ffffffff811c40d0>] sys_fsync+0x10/0x20 [706560.640383] [<ffffffff816d495d>] system_call_fastpath+0x1a/0x1f When this happens the only way to make everything working again is a full reboot, but in order to do that I'm forced to use this command after I've manually stopped all running processes echo b > /proc/sysrq-trigger otherwise normal reboot process hangs forever. I've tracked reboots script and I've found out that also the reboot process hangs on a sync call, this one in /etc/init.d/sendsigs (I'm on ubuntu) # Flush the kernel I/O buffer before we start to kill # processes, to make sure the IO of already stopped services to # not slow down the remaining processes to a point where they # are accidentily killed with SIGKILL because they did not # manage to shut down in time. sync I'm almost sure that the cause of this is an hardware issue (the RAID controller???) also because I've other two machines with the same hardware and software configuration and they don't suffer of this, but I can't find any hint in syslog or dmesg. I've also installed smartmontools and mcelog packages but none of them did report any issue. What can I do to track the cause of this issue? Today is happened again, here is the status of system after triggering a reboot init---console-kit-dae---64*[{console-kit-dae}] +-dbus-daemon +-mcelog +-mysqld---{mysqld} +-newrelic-daemon---newrelic-daemon---11*[{newrelic-daemon}] +-ntpd +-polkitd---{polkitd} +-python3 +-rpc.idmapd +-rpc.statd +-rpcbind +-sh---rc---S20sendsigs---sync +-smartd +-snmpd +-sshd---sshd---zsh---sudo---zsh---pstree +-sshd---sshd---zsh---sudo---zsh And here is the status of sync process # ps aux | grep sync root 3637 0.1 0.0 4352 372 ? D 05:53 0:00 sync i.e. Uninterruptible sleep... Hardware specs as reported by lshw I think the raid controller is a fake raid. I usually don't deal with hardware (and for the record I don't have physical access to it) description: Computer product: X7DBP () vendor: Supermicro version: 0123456789 serial: 0123456789 width: 64 bits capabilities: smbios-2.4 dmi-2.4 vsyscall32 configuration: administrator_password=disabled boot=normal frontpanel_password=unknown keyboard_password=unknown power-on_password=disabled uuid=53D19F64-D663-A017-8922-0030487C1FEE *-core description: Motherboard product: X7DBP vendor: Supermicro physical id: 0 version: PCB Version serial: 0123456789 *-firmware description: BIOS vendor: Phoenix Technologies LTD physical id: 0 version: 6.00 date: 05/29/2007 size: 106KiB capacity: 960KiB capabilities: pci pnp upgrade shadowing escd cdboot bootselect edd int13floppy2880 acpi usb ls120boot zipboot biosbootspecification *-storage description: RAID bus controller product: 631xESB/632xESB SATA RAID Controller vendor: Intel Corporation physical id: 1f.2 bus info: pci@0000:00:1f.2 version: 09 width: 32 bits clock: 66MHz capabilities: storage pm bus_master cap_list configuration: driver=ahci latency=0 resources: irq:19 ioport:18a0(size=8) ioport:1874(size=4) ioport:1878(size=8) ioport:1870(size=4) ioport:1880(size=32) memory:d8500400-d85007ff

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• redhat Apache fast-cgi selinux permissions

  - by Alejo JM

  My apache installation is running php as fastcgi, and the virtual hosts are pointing to /home/*/public_html. and the fastcgi are home/*/cgi-bin/php.fcgi the public_html setup with selinux was: /usr/sbin/setsebool -P httpd_enable_homedirs 1 chcon -R -t httpd_sys_content_t /home/someuser/public_html The owner and group are the user, for example the user "someuser": ls -all /home/someuser/cgi-bin/ drwxr-xr-x 2 someuser someuser 4096 Sep 7 13:14 . drwx--x--x 6 someuser someuser 4096 Sep 6 18:17 .. -rwxr-xr-x 1 someuser someuser 308 Sep 7 13:14 php.fcgi ls -all /home/someuser/public_html/ | greep info.php -rw-r--r-- 1 someuser someuser 24 Sep 3 16:24 info.php When is visits the site I get "Forbidden ..." and the log said: [Fri Sep 07 12:02:51 2012] [error] [client x.x.x.x] (13)Permission denied: access to /cgi-bin/php.fcgi/info.php denied My selinux conf is: SELINUX=enforcing SELINUXTYPE=targeted SETLOCALDEFS=0 So I kill Selinux (SELINUX=disabled), reboot the system and everything works !!!!! The problem is Selinux, I don't want disable Selinux. I trying this with no success: setsebool -P httpd_enable_cgi 1 chcon -t httpd_sys_script_exec_t /home/someuser/cgi-bin/php.fcgi chcon -R -t httpd_sys_content_t /home/someuser/cgi-bin Or maybe is better change Selinux SELINUX=enforcing to SELINUX=permissive And disable selinux for httpd ? (I think I better find the correct configuration) Thanks for any suggestion on this matter My environment: Red Hat Enterprise Linux Server release 5.8 (Tikanga) Server version: Apache/2.2.3 PHP 5.1.6 (cli) (built: Jun 22 2012 06:20:25) Copyright (c) 1997-2006 The PHP Group Zend Engine v2.1.0, Copyright (c) 1998-2006 Zend Technologies Some logs: ps -ZC httpd LABEL PID TTY TIME CMD system_u:system_r:httpd_t 2822 ? 00:00:00 httpd system_u:system_r:httpd_t 2823 ? 00:00:00 httpd system_u:system_r:httpd_t 2824 ? 00:00:00 httpd system_u:system_r:httpd_t 2825 ? 00:00:00 httpd system_u:system_r:httpd_t 2826 ? 00:00:00 httpd system_u:system_r:httpd_t 2836 ? 00:00:00 httpd system_u:system_r:httpd_t 2837 ? 00:00:00 httpd system_u:system_r:httpd_t 2838 ? 00:00:00 httpd system_u:system_r:httpd_t 2839 ? 00:00:00 httpd system_u:system_r:httpd_t 2840 ? 00:00:00 httpd getsebool -a | grep httpd allow_httpd_anon_write --> off allow_httpd_bugzilla_script_anon_write --> off allow_httpd_cvs_script_anon_write --> off allow_httpd_mod_auth_pam --> off allow_httpd_nagios_script_anon_write --> off allow_httpd_prewikka_script_anon_write --> off allow_httpd_squid_script_anon_write --> off allow_httpd_sys_script_anon_write --> off httpd_builtin_scripting --> on httpd_can_network_connect --> off httpd_can_network_connect_db --> off httpd_can_network_relay --> off httpd_can_sendmail --> on httpd_disable_trans --> off httpd_enable_cgi --> on httpd_enable_ftp_server --> off httpd_enable_homedirs --> on httpd_execmem --> off httpd_read_user_content --> off httpd_rotatelogs_disable_trans --> off httpd_setrlimit --> off httpd_ssi_exec --> off httpd_suexec_disable_trans --> off httpd_tty_comm --> on httpd_unified --> on httpd_use_cifs --> off httpd_use_nfs --> off

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• How to install ia32-libs on Wheezy?

  - by javano

  I have seen a couple of questions on ServerFault relating to installing ia32-libs on a 64bit machine but the solutions aren't working for me (I don't think any of these questions where for Wheezy specifically I'm not sure how to proceed); root@server:/home/# apt-get install -f ia32-libs Reading package lists... Done Building dependency tree Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: ia32-libs : Depends: ia32-libs-i386 php5 : Depends: libapache2-mod-php5 (>= 5.4.4-14+deb7u2) but it is not going to be installed or libapache2-mod-php5filter (>= 5.4.4-14+deb7u2) but it is not going to be installed or php5-cgi (>= 5.4.4-14+deb7u2) but it is not going to be installed or php5-fpm (>= 5.4.4-14+deb7u2) but it is not going to be installed php5-mysql : Depends: phpapi-20100525 E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages. root@server:/home/# sudo apt-get install ia32-libs-i386 Reading package lists... Done Building dependency tree Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: ia32-libs-i386:i386 : Depends: freeglut3:i386 (>= 2.6.0-1) but it is not going to be installed Depends: lesstif2:i386 (>= 1:0.95.2-1) but it is not going to be installed Depends: libacl1:i386 (>= 2.2.49-4) but it is not going to be installed Depends: libasyncns0:i386 (>= 0.3-1.1) but it is not going to be installed Depends: libattr1:i386 (>= 1:2.4.44-2) but it is not going to be installed Depends: libaudio2:i386 (>= 1.9.2-4) but it is not going to be installed Depends: libaudiofile1:i386 (>= 0.2.6-8) but it is not going to be installed Depends: libavahi-client3:i386 (>= 0.6.27-2+squeeze1) but it is not going to be installed Depends: libavahi-common3:i386 (>= 0.6.27-2+squeeze1) but it is not going to be installed Depends: libbsd0:i386 (>= 0.2.0-1) but it is not going to be installed Depends: libcap2:i386 (>= 1:2.19-3) but it is not going to be installed Depends: libcomerr2:i386 (>= 1.41.12-4stable1) but it is not going to be installed Depends: libcups2:i386 (>= 1.4.4-7+squeeze1) but it is not going to be installed Depends: libcurl3:i386 (>= 7.21.0-2) but it is not going to be installed Depends: libdbus-1-3:i386 (>= 1.2.24-4+squeeze1) but it is not going to be installed Depends: libdirectfb-1.2-9:i386 (>= 1.2.10.0-4) but it is not going to be installed Depends: libdrm-intel1:i386 (>= 2.4.21-1~squeeze3) but it is not going to be installed Depends: libdrm-radeon1:i386 (>= 2.4.21-1~squeeze3) but it is not going to be installed Depends: libdrm2:i386 (>= 2.4.21-1~squeeze3) but it is not going to be installed Depends: libedit2:i386 (>= 2.11-20080614-2) but it is not going to be installed Depends: libesd0:i386 (>= 0.2.41-8) but it is not going to be installed Depends: libexif12:i386 (>= 0.6.19-1) but it is not going to be installed Depends: libexpat1:i386 (>= 2.0.1-7) but it is not going to be installed Depends: libflac8:i386 (>= 1.2.1-2+b1) but it is not going to be installed Depends: libfltk1.1:i386 (>= 1.1.10-2+b1) but it is not going to be installed Depends: libfontconfig1:i386 (>= 2.8.0-2.1) but it is not going to be installed Depends: libfreetype6:i386 (>= 2.4.2-2.1+squeeze3) but it is not going to be installed Depends: libgcrypt11:i386 (>= 1.4.5-2) but it is not going to be installed Depends: libgdbm3:i386 (>= 1.8.3-9) but it is not going to be installed Depends: libgl1-mesa-dri:i386 (>= 7.7.1-5) but it is not going to be installed Depends: libgl1-mesa-glx:i386 (>= 7.7.1-5) but it is not going to be installed Depends: libglu1-mesa:i386 (>= 7.7.1-5) but it is not going to be installed Depends: libgnutls26:i386 (>= 2.8.6-1) but it is not going to be installed Depends: libgpg-error0:i386 (>= 1.6-1) but it is not going to be installed Depends: libgphoto2-2:i386 (>= 2.4.6-3) but it is not going to be installed Depends: libgphoto2-port0:i386 (>= 2.4.6-3) but it is not going to be installed Depends: libgssapi-krb5-2:i386 (>= 1.8.3+dfsg-4squeeze2) but it is not going to be installed Depends: libice6:i386 (>= 2:1.0.6-2) but it is not going to be installed Depends: libidn11:i386 (>= 1.15-2) but it is not going to be installed Depends: libieee1284-3:i386 (>= 0.2.11-6) but it is not going to be installed Depends: libjack-jackd2-0:i386 (>= 1.9.5~dfsg-14) but it is not going to be installed or libjack0:i386 (>= 1:0.118+svn3796-7) but it is not going to be installed Depends: libjpeg62:i386 (>= 6b1-1) but it is not going to be installed Depends: libjpeg8:i386 (>= 8b-1) but it is not going to be installed Depends: libk5crypto3:i386 (>= 1.8.3+dfsg-4squeeze2) but it is not going to be installed Depends: libkeyutils1:i386 (>= 1.4-1) but it is not going to be installed Depends: libkrb5-3:i386 (>= 1.8.3+dfsg-4squeeze2) but it is not going to be installed Depends: libkrb5support0:i386 (>= 1.8.3+dfsg-4squeeze2) but it is not going to be installed Depends: liblcms1:i386 (>= 1.18.dfsg-1.2+b3) but it is not going to be installed Depends: libltdl7:i386 (>= 2.2.6b-2) but it is not going to be installed Depends: liblzo2-2:i386 (>= 2.03-2) but it is not going to be installed Depends: libmpg123-0:i386 (>= 1.12.1-3) but it is not going to be installed Depends: libnspr4-0d:i386 (>= 4.8.6-1) but it is not going to be installed Depends: libnss3-1d:i386 (>= 3.12.8-1+squeeze4) but it is not going to be installed Depends: libogg0:i386 (>= 1.2.0~dfsg-1) but it is not going to be installed Depends: libopenal1:i386 (>= 1:1.12.854-2) but it is not going to be installed Depends: libpam0g:i386 (>= 1.1.1-6.1+squeeze1) but it is not going to be installed Depends: libpng12-0:i386 (>= 1.2.44-1+squeeze1) but it is not going to be installed Depends: libpopt0:i386 (>= 1.16-1) but it is not going to be installed Depends: libpulse0:i386 (>= 0.9.21-3+squeeze1) but it is not going to be installed Depends: libsamplerate0:i386 (>= 0.1.7-3) but it is not going to be installed Depends: libsane:i386 (>= 1.0.21-9) but it is not going to be installed Depends: libsasl2-2:i386 (>= 2.1.23.dfsg1-7) but it is not going to be installed Depends: libsdl1.2debian:i386 (>= 1.2.15) but it is not going to be installed Depends: libselinux1:i386 (>= 2.0.96-1) but it is not going to be installed Depends: libsigc++-2.0-0c2a:i386 (>= 2.2.4.2-1) but it is not going to be installed Depends: libsm6:i386 (>= 2:1.1.1-1) but it is not going to be installed Depends: libsndfile1:i386 (>= 1.0.21-3+squeeze1) but it is not going to be installed Depends: libsqlite3-0:i386 (>= 3.7.3-1) but it is not going to be installed Depends: libssh2-1:i386 (>= 1.2.6-1) but it is not going to be installed Depends: libssl1.0.0:i386 (>= 1) but it is not going to be installed Depends: libstdc++5:i386 (>= 1:3.3.6-20) but it is not going to be installed Depends: libsvga1:i386 (>= 1:1.4.3-29) but it is not going to be installed Depends: libsysfs2:i386 (>= 2.1.0+repack-1) but it is not going to be installed Depends: libtasn1-3:i386 (>= 2.7-1) but it is not going to be installed Depends: libtdb1:i386 (>= 1.2.1-2+b1) but it is not going to be installed Depends: libtiff4:i386 (>= 3.9.4-5+squeeze3) but it is not going to be installed Depends: libts-0.0-0:i386 (>= 1.0-7) but it is not going to be installed Depends: libusb-0.1-4:i386 (>= 2:0.1.12-16) but it is not going to be installed Depends: libuuid1:i386 (>= 2.17.2-9) but it is not going to be installed Depends: libvorbis0a:i386 (>= 1.3.1-1) but it is not going to be installed Depends: libvorbisenc2:i386 (>= 1.3.1-1) but it is not going to be installed Depends: libvorbisfile3:i386 (>= 1.3.1-1) but it is not going to be installed Depends: libwrap0:i386 (>= 7.6.q-19) but it is not going to be installed Depends: libx11-6:i386 (>= 2:1.3.3-4) but it is not going to be installed Depends: libx86-1:i386 (>= 1.1+ds1-6) but it is not going to be installed Depends: libxau6:i386 (>= 1:1.0.6-1) but it is not going to be installed Depends: libxaw7:i386 (>= 2:1.0.7-1) but it is not going to be installed Depends: libxcb-render-util0:i386 (>= 0.3.6-1) but it is not going to be installed Depends: libxcb-render0:i386 (>= 1.6-1) but it is not going to be installed Depends: libxcb1:i386 (>= 1.6-1) but it is not going to be installed Depends: libxcomposite1:i386 (>= 1:0.4.2-1) but it is not going to be installed Depends: libxcursor1:i386 (>= 1:1.1.10-2) but it is not going to be installed Depends: libxdamage1:i386 (>= 1:1.1.3-1) but it is not going to be installed Depends: libxdmcp6:i386 (>= 1:1.0.3-2) but it is not going to be installed Depends: libxext6:i386 (>= 2:1.1.2-1) but it is not going to be installed Depends: libxfixes3:i386 (>= 1:4.0.5-1) but it is not going to be installed Depends: libxft2:i386 (>= 2.1.14-2) but it is not going to be installed Depends: libxi6:i386 (>= 2:1.3-6) but it is not going to be installed Depends: libxinerama1:i386 (>= 2:1.1-3) but it is not going to be installed Depends: libxml2:i386 (>= 2.7.8.dfsg-2+squeeze1) but it is not going to be installed Depends: libxmu6:i386 (>= 2:1.0.5-2) but it is not going to be installed Depends: libxmuu1:i386 (>= 2:1.0.5-2) but it is not going to be installed Depends: libxp6:i386 (>= 1:1.0.0.xsf1-2) but it is not going to be installed Depends: libxpm4:i386 (>= 1:3.5.8-1) but it is not going to be installed Depends: libxrandr2:i386 (>= 2:1.3.0-3) but it is not going to be installed Depends: libxrender1:i386 (>= 1:0.9.6-1) but it is not going to be installed Depends: libxslt1.1:i386 (>= 1.1.26-6) but it is not going to be installed Depends: libxss1:i386 (>= 1:1.2.0-2) but it is not going to be installed Depends: libxt6:i386 (>= 1:1.0.7-1) but it is not going to be installed Depends: libxtst6:i386 (>= 2:1.1.0-3) but it is not going to be installed Depends: libxv1:i386 (>= 2:1.0.5-1) but it is not going to be installed Depends: libxxf86vm1:i386 (>= 1:1.1.0-2) but it is not going to be installed Depends: odbcinst1debian2:i386 (>= 2.2.14p2-1) but it is not going to be installed Depends: libodbc1:i386 but it is not going to be installed Depends: xaw3dg:i386 (>= 1.5+E-18) but it is not going to be installed php5 : Depends: libapache2-mod-php5 (>= 5.4.4-14+deb7u2) but it is not going to be installed or libapache2-mod-php5filter (>= 5.4.4-14+deb7u2) but it is not going to be installed or php5-cgi (>= 5.4.4-14+deb7u2) but it is not going to be installed or php5-fpm (>= 5.4.4-14+deb7u2) but it is not going to be installed php5-mysql : Depends: phpapi-20100525 E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages. root@server:/home/# dpkg --print-architecture amd64 root@server:/home/# dpkg --print-foreign-architectures i386 root@server:/home/# lsb_release -a No LSB modules are available. Distributor ID: Debian Description: Debian GNU/Linux 7.1 (wheezy) Release: 7.1 Codename: wheezy root@server:/home/# uname -a Linux servername 3.2.0-4-amd64 #1 SMP Debian 3.2.46-1 x86_64 GNU/Linux root@server:/home/# cat /etc/apt/sources.list deb http://ftp.us.debian.org/debian stable main contrib non-free

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• phpMyAdmin setup issues

  - by EquinoX

  I am trying to follow the tutorial here to setup the user and pass. It says there that "this section is only applicable if your MySQL server is running with --skip-show-database". First question is, how do I check if MySQl server is running with --skip-show-database? Is there any way I can access phpMyAdmin SQL query window without logging in? Otherwise I'd have to execute this SQL from command line. I am also getting this: Cannot load mcrypt extension. Please check your PHP configuration. I have added mcrypt.so to php.ini and doing the following command proves that I have it. [root@DT html]# rpm -qa | grep mcrypt mcrypt-2.6.8-1.el5 php-mcrypt-5.3.5-1.1.w5 libmcrypt-2.5.8-4.el5.centos [root@DT html]# php -v PHP 5.3.5 (cli) (built: Feb 19 2011 13:10:09) Copyright (c) 1997-2010 The PHP Group Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies Now when I go to phpinfo() and search for mcrypt it can find it inside the Configure Command row ('--with-mcrypt=shared,/usr'). So, what to do next?. UPDATE: I didn't put extension=mcrypt.so in php.ini as it will complain the following: PHP Warning: Module 'mcrypt' already loaded in Unknown on line 0 Here's my nginx.conf: #user nobody; worker_processes 2; #error_log logs/error.log; #error_log logs/error.log notice; #error_log logs/error.log info; #pid logs/nginx.pid; events { worker_connections 1024; } http { include mime.types; default_type application/octet-stream; #log_format main '$remote_addr - $remote_user [$time_local] "$request" ' # '$status $body_bytes_sent "$http_referer" ' # '"$http_user_agent" "$http_x_forwarded_for"'; #access_log logs/access.log main; sendfile on; #tcp_nopush on; #keepalive_timeout 0; keepalive_timeout 65; gzip on; server { listen 80; root /usr/share/nginx/html; server_name localhost; #charset koi8-r; #access_log logs/host.access.log main; location / { #root html; index index.html index.htm; } #error_page 404 /404.html; # redirect server error pages to the static page /50x.html # error_page 500 502 503 504 /50x.html; location = /50x.html { #root html; } # proxy the PHP scripts to Apache listening on 127.0.0.1:80 # #location ~ \.php$ { # proxy_pass http://127.0.0.1; #} # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000 # location ~ \.php$ { #root /usr/local/nginx/html; fastcgi_pass 127.0.0.1:9000; fastcgi_index index.php; fastcgi_param SCRIPT_FILENAME /usr/share/nginx/html$fastcgi_script _name; include fastcgi_params; } # deny access to .htaccess files, if Apache's document root # concurs with nginx's one location ~ /\.ht { deny all; } } # another virtual host using mix of IP-, name-, and port-based configuration # #server { # listen 8000; # listen somename:8080; # server_name somename alias another.alias; # location / { # root html; # index index.html index.htm; # } #} # HTTPS server # #server { # listen 443; # server_name localhost; # ssl on; # ssl_certificate cert.pem; # ssl_certificate_key cert.key; # ssl_session_timeout 5m; # ssl_protocols SSLv2 SSLv3 TLSv1; # ssl_ciphers ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP; # ssl_prefer_server_ciphers on; # location / { # root html; # index index.html index.htm; # } #} }

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• IPv6: Should I have private addresses?

  - by AlReece45

  Right now, we have a rack of servers. Every server right now has at least 2 IP addresses, one for the public interface, another for the private. The servers that have SSL websites on them have more IP addresses. We also have virtual servers, that are configured similarly. Private Network The private range is currently just used for backups and monitoring. Its a gigabit port, the interface usage does not usually get very high. There are other technologies we're considering using that would use this port: iSCSI (implementations usually recommends dedicating an interface to it, which would be yet another IP network), VPN to get access to the private range (something I'd rather avoid) dedicated database servers LDAP centralized configuration (like puppet) centralized logging We don't have any private addresses in our DNS records (only public addresses). For our servers to utilize the correct IP address for the right interface (and not hard code the IP address) probably requires setting up a private DNS server (So now we add 2 different dns entries to 2 different systems). Public Network Our public range has a variety of services include web, email, and ftp. There is a hardware firewall between our network and the "public" network. We have (relatively secure) method to instruct the firewall to open and close administrative access (web interfaces, ssh, etc) for our current IP address. With either solution discussed, the host-based firewalls will be configured as well. The public network currently runs at a dedicated 20Mbps link. There are a couple of legacy servers with fast-ethernet ports, but they are scheduled for decommissioning. All of the other production boxes have at least 2 Gigabit Ethernet ports. The more traffic-heavy servers have 4-6 available (none is using more than the 2 Gigabit ports right now). IPv6 I want to get an IPv6 prefix from our ISP. So at least every "server" has at least one IPv6 interface. We'll still need to keep the IPv4 addressees up and available for legacy clients (web servers and email at the very least). We have two IP networks right now. Adding the public IPv6 address would make it three. Just use IPv6? I'm thinking about just dumping the private IPv4 range and using the IPv6 range as the primary means of all communications. If an interface starts reaching its capacity, utilize the newly free interfaces to create a trunk. It has the advantage that if either the public or private traffic needs to exceed 1Gbps. The traffic for each interface is already analyzed on a regular basis to predict future bandwidth use. In the rare instances where bandwidth unexpected peaks: utilize QoS to ensure traffic (like our limited SSH access) is prioritized correctly so the problem can be corrected (if possible, our WAN is the bottleneck right now). It also has the advantage of not needing to make an entry for every private address. We may have private DNS (or just LDAP), but it'll be much more limited in scope with less entries to duplicate. Summary I'm trying to make this network as "simple" as possible. At the same time, I want to make sure its reliable, upgradeable, scalable, and (eventually) redundant. Having one IPv6 network, and a legacy IPv4 network seems to be the best solution to me. Regarding using assigned IPv6 addresses for both networks, sharing the available bandwidth on one (more trunked if needed): Are there any technical disadvantages (limitations, buffers, scalability)? Are there any other security considerations (asides from firewalls mentioned above) to consider? Are there regulations or other security requirements (like PCI-DSS) that this doesn't meet? Is there typical software for setting up a Linux network that doesn't have IPv6 support yet? (logging, ldap, puppet) Some other thing I didn't consider?

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• Vista 64-bit, DISK BOOT FAILURE

  - by weka

  So I have this Acer Aspire AX3200-U3600A with Windows Vista (64-bit). Every night I turn it off and turn it back on in the morning. Around three weeks ago, I did a fresh factory reimage. Good as new. Then around two days ago, when I turned it on, I noticed it was running extremly slow. As in, it would often freeze up while I had multiple applications open when it usually never froze up. So I decided to restart my computer. Big mistake. My computer froze right after I clicked shut-down. I waited a while. Nothing. Waited some minutes. Nope. I decided to shut it down by pressing the power button. Here is where the problems begin. When I turned it back on, I saw the Windows logo and loading bar and then it loaded to black. I turned it off again forcefully by power button and then once more... then I got: AMD Data Change... Update New Data to DMI! then later the screen clears and I get: AHCI Option ROM BIOS Revision: 01.05.92 Date: 02-19-2008 Copyright (c) 2006-2008 Phoenix Technologies, LTD Port 01: Reset Port Error!! Port 02: then the screen clears again but this time, this loads from the bottom: Nvidia Boot Agent 249.0542 (copyright stuff... blah blah) PXE-E61: Media test failure, check cable. PXE-M0F: Exiting Nvidia Boot Agent DISK BOOT FAILURE, INSERT SYSTEM DISK AND PRESS ENTER. So I try to go into Safe Mode. Well, first of all it doesn't load as fast. After it loads disk.sys from windows/drivers, it will wait a while (2-3 mins) THEN load. However it loads the Acer eRecovery Management Tool. I have three options: Reset computer to factory default, Restore computer from user's backup, or Exit. However, the top two options are gray and disabled where as the Exit is in blue and definitely clickable. So obviously safe mode is not there... A strong thing to note: In the beginning when all of this started, I did a Boot Windows Normal from pressing f8 and I got to my desktop! It logged me in. I could see the icons on my files. However my desktop was extremely slow as in when I clicked on the Start menu, it would wait a while, then load up the menu with JUST the gradient, no text or icons... so as you can see... it saw my HDD? Also, before anyone says, I have NO USB plugged in. My mouse and keyboard are not USB inputs, I assure you. And this came without a recovery CD AND when I went in BIOS, to change the BOOT ORDER, I did NOT see a CD-ROM option. And when I tried pressing ALT+F10 to get into Acer eRecovery Management, the top two options were disabled as well. But sometimes on start-up, I get: Windows has encountered a problem communicating with a device connected to your computer. This error can be caused by unplugging a removable storage device such as an external USB drive while the device is in use, or by faulty hardware such as a hard drive or CD-ROM drive that is failing. Make sure any removeable storage is properly connected and then restart your computer. If you continue to receive this error message, contact the hardware manufacturer. Status: 0xc00000e9 Info: An unexpected I/O error has occured. Then I tried Last Known Good Configuration Settings, that gives me a BSOD. What should I do/

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• Trying to prevent Windows from hibernating/sleeping automatically

  - by user328821

  My Dell XPS 8700 (Win 7) suddenly began putting itself to sleep at 6pm daily, even if I'm typing. I don't know what caused this to occur, except possibly a windows update that took place in the middle of the night. I initially went into settings for power and saw 2 plans set up, one from Dell and the other window's Power saver plan. I set both to never for sleep and hibernate yet it still occurred. I have current drivers and a fairly new UPS that has software to set to shutdown only after power loss. Dell is of little help, can anyone point me in the right direction? I did do the powerdfg -energy program and came up with this: Power Efficiency Diagnostics Report Scan Time 2014-05-08T19:21:48Z Scan Duration 60 seconds System Manufacturer Dell Inc. System Product Name XPS 8700 BIOS Date 08/23/2013 BIOS Version A04 OS Build 7601 Platform Role PlatformRoleDesktop Plugged In true Process Count 115 Thread Count 1631 Report GUID {097caf99-039b-44c3-b154-d797bfbfdfcc} Analysis Results Errors Power Policy:Sleep timeout is disabled (Plugged In) The computer is not configured to automatically sleep after a period of inactivity. System Availability Requests:System Required Request The device or driver has made a request to prevent the system from automatically entering sleep. Requesting Driver Instance HDAUDIO\FUNC_01&VEN_10EC&DEV_0899&SUBSYS_102805B7&REV_1000\4&220b1bbc&0&0001 Requesting Driver Device Realtek High Definition Audio CPU Utilization:Processor utilization is high The average processor utilization during the trace was high. The system will consume less power when the average processor utilization is very low. Review processor utilization for individual processes to determine which applications and services contribute the most to total processor utilization. Average Utilization (%) 9.48 Warnings Platform Timer Resolution:Platform Timer Resolution The default platform timer resolution is 15.6ms (15625000ns) and should be used whenever the system is idle. If the timer resolution is increased, processor power management technologies may not be effective. The timer resolution may be increased due to multimedia playback or graphical animations. Current Timer Resolution (100ns units) 10000 Maximum Timer Period (100ns units) 156001 Platform Timer Resolution:Outstanding Kernel Timer Request A kernel component or device driver has requested a timer resolution smaller than the platform maximum timer resolution. Requested Period 10000 Request Count 2 Platform Timer Resolution:Outstanding Timer Request A program or service has requested a timer resolution smaller than the platform maximum timer resolution. Requested Period 10000 Requesting Process ID 8672 Requesting Process Path \Device\HarddiskVolume3\Program Files (x86)\Mozilla Firefox\firefox.exe Platform Timer Resolution:Outstanding Timer Request A program or service has requested a timer resolution smaller than the platform maximum timer resolution. Requested Period 100000 Requesting Process ID 1212 Requesting Process Path \Device\HarddiskVolume3\Windows\System32\svchost.exe Power Policy:802.11 Radio Power Policy is Maximum Performance (Plugged In) The current power policy for 802.11-compatible wireless network adapters is not configured to use low-power modes. CPU Utilization:Individual process with significant processor utilization. This process is responsible for a significant portion of the total processor utilization recorded during the trace. Process Name audiodg.exe PID 1304 Average Utilization (%) 4.73 Module Average Module Utilization (%) \Device\HarddiskVolume3\Windows\System32\msvcrt.dll 1.88 \Device\HarddiskVolume3\Windows\System32\MaxxAudioAPO5064.dll 1.77 \Device\HarddiskVolume3\Windows\System32\AudioEng.dll 0.80 CPU Utilization:Individual process with significant processor utilization. This process is responsible for a significant portion of the total processor utilization recorded during the trace. Process Name thunderbird.exe PID 6036 Average Utilization (%) 0.35 Module Average Module Utilization (%) \Device\HarddiskVolume3\Program Files (x86)\Mozilla Thunderbird\xul.dll 0.16 \Device\HarddiskVolume3\Program Files (x86)\Mozilla Thunderbird\mozjs.dll 0.05 \SystemRoot\System32\win32k.sys 0.03 CPU Utilization:Individual process with significant processor utilization. This process is responsible for a significant portion of the total processor utilization recorded during the trace. Process Name dwm.exe PID 1340 Average Utilization (%) 0.25 Module Average Module Utilization (%) \Device\HarddiskVolume3\Windows\System32\dwmcore.dll 0.08 \Device\HarddiskVolume3\Windows\System32\nvwgf2umx.dll 0.05 \SystemRoot\system32\ntoskrnl.exe 0.03 CPU Utilization:Individual process with significant processor utilization. This process is responsible for a significant portion of the total processor utilization recorded during the trace.

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• Computer science undergraduate project ideas

  - by Mehrdad Afshari

  Hopefully, I'm going to finish my undergraduate studies next semester and I'm thinking about the topic of my final project. And yes, I've read the questions with duplicate title. I'm asking this from a bit different viewpoint, so it's not an exact dupe. I've spent at least half of my life coding stuff in different languages and frameworks so I'm not looking at this project as a way to learn much about coding and preparing for real world apps or such. I've done lots of those already. But since I have to do it to complete my degree, I felt I should spend my time doing something useful instead of throwing the whole thing out. I'm planning to make it an open source project or a hosted Web app (depending on the type) if I can make a high quality thing out of it, so I decided to ask StackOverflow what could make a useful project. Situation I've plenty of freedom about the topic. They also require 30-40 pages of text describing the project. I have the following points in mind (the more satisfied, the better): Something useful for software development Something that benefits the community Having academic value is great Shouldn't take more than a month of development (I know I'm lazy). Shouldn't be related to advanced theoretical stuff (soft computing, fuzzy logic, neural networks, ...). I've been a business-oriented software developer. It should be software oriented. While I love hacking microcontrollers and other fun embedded electronic things, I'm not really good at soldering and things like that. I'm leaning toward a Web application (think StackOverflow, PasteBin, NerdDinner, things like those). Technology It's probably going to be done in .NET (C#, F#) and Windows platform. If I really like the project (cool low level hacking), I might actually slip to C/C++. But really, C# is what I'm efficient at. Ideas Programming language, parsing and compiler related stuff: Designing a domain specific programming language and compiler Templating language compiled to C# or IL Database tools and related code generation stuff Web related technologies: ASP.NET MVC View engine doing something cool (don't know what exactly...) Specific-purpose, small, fast ASP.NET-based Web framework Applications: Visual Studio plugin to integrate with Bazaar (it's too much work, I think). ASP.NET based, jQuery-powered issue tracker (and possibly, project lifecycle management as a whole - poor man's TFS) Others: Something related to GPGPU Looking forward for great ideas! Unfortunately, I can't help on a currently existing project. I need to start my own to prevent further problems (as it's an undergrad project, nevertheless).

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• Interesting issue with WCF wsHttpBinding through a Firewall

  - by Marko

  I have a web application deployed in an internet hosting provider. This web application consumes a WCF Service deployed at an IIS server located at my company’s application server, in order to have data access to the company’s database, the network guys allowed me to expose this WCF service through a firewall for security reasons. A diagram would look like this. [Hosted page] --- (Internet) --- |Firewall <Public IP>:<Port-X >| --- [IIS with WCF Service <Comp. Network Ip>:<Port-Y>] link text I also wanted to use wsHttpBinding to take advantage of its security features, and encrypt sensible information. After trying it out I get the following error: Exception Details: System.ServiceModel.EndpointNotFoundException: The message with To 'http://<IP>:<Port>/service/WCFService.svc' cannot be processed at the receiver, due to an AddressFilter mismatch at the EndpointDispatcher. Check that the sender and receiver's EndpointAddresses agree. Doing some research I found out that wsHttpBinding uses WS-Addressing standards, and reading about this standard I learned that the SOAP header is enhanced to include tags like ‘MessageID’, ‘ReplyTo’, ‘Action’ and ‘To’. So I’m guessing that, because the client application endpoint specifies the Firewall IP address and Port, and the service replies with its internal network address which is different from the Firewall’s IP, then WS-Addressing fires the above message. Which I think it’s a very good security measure, but it’s not quite useful in my scenario. Quoting the WS-Addressing standard submission (http://www.w3.org/Submission/ws-addressing/) "Due to the range of network technologies currently in wide-spread use (e.g., NAT, DHCP, firewalls), many deployments cannot assign a meaningful global URI to a given endpoint. To allow these ‘anonymous’ endpoints to initiate message exchange patterns and receive replies, WS-Addressing defines the following well-known URI for use by endpoints that cannot have a stable, resolvable URI. http://schemas.xmlsoap.org/ws/2004/08/addressing/role/anonymous" HOW can I configure my wsHttpBinding Endpoint to address my Firewall’s IP and to ignore or bypass the address specified in the ‘To’ WS-Addressing tag in the SOAP message header? Or do I have to change something in my service endpoint configuration? Help and guidance will be much appreciated. Marko. P.S.: While I find any solution to this, I’m using basicHttpBinding with absolutely no problem of course.

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• Application Architecture using WCF and System.AddIn

  - by Silverhalide

  A little background -- we're designing an application that uses a client/server architecture consisting of: A server which loads server-side modules, potentially developed by other teams. A client which loads corresponding client-side modules (also potentially developed by those other teams; each client module corresponds with a server module). The client side communicates with the server side for general coordination, and as well as module specific tasks. (At this point, I think that means client talks to server, client modules talk to server modules.) Environment is .NET 3.5, and client side is WPF. The deployment scenario introduces the potential to upgrade the server, any server-side module, the client, and any client-side module independently. However, being able to "work" using mismatched versions is required. I'm therefore concerned about versioning issues. My thinking so far: A Windows Service for the server. Using System.AddIn for the server to load and communicate with the server modules will give us the greatest flexibility in terms of version compatability between server and server modules. The server and each server module vend WCF services for communication to the client side; communication between the server and a server module, or between two server modules use the AddIn contracts. (One advantage of this is that a module can expose a different interface within the server and outside it.) Similarly, the client uses System.AddIn to find, load, and communicate with the client modules. Client communications with client modules is via the AddIn interface; communications from the client and from client modules to the server side are via WCF. For maximum resilience, each module will run in a separate app-domain. In general, the system has modest performance requirements, so marshalling and crossing process boundaries is not expected to be a performance concern. (Performance requirement is basically summed up by: don't get in the way of the other parts of the system not described here.) My questions are around the idea of having two different communication and versioning models to work with which will be an added burden on our developers. System.AddIn seems quite powerful, but also a little unwieldly. (I'm also unsure of Microsoft's commitment to it in the future.) On the other hand, I'm not thrilled with WCF's versioning capabilities. I have a feeling that it would be possible to implement the System.AddIn view/adapter/contract system within WCF, but being fairly new to both technologies, I would have no idea of where to start. So... Am I on the right track here? Am I doing this the hard way? Are there gotchas I need to be aware of on this road? Thanks.

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