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  • Routes on a sphere surface - Find geodesic?

    - by CaNNaDaRk
    I'm working with some friends on a browser based game where people can move on a 2D map. It's been almost 7 years and still people play this game so we are thinking of a way to give them something new. Since then the game map was a limited plane and people could move from (0, 0) to (MAX_X, MAX_Y) in quantized X and Y increments (just imagine it as a big chessboard). We believe it's time to give it another dimension so, just a couple of weeks ago, we began to wonder how the game could look with other mappings: Unlimited plane with continous movement: this could be a step forward but still i'm not convinced. Toroidal World (continous or quantized movement): sincerely I worked with torus before but this time I want something more... Spherical world with continous movement: this would be great! What we want Users browsers are given a list of coordinates like (latitude, longitude) for each object on the spherical surface map; browsers must then show this in user's screen rendering them inside a web element (canvas maybe? this is not a problem). When people click on the plane we convert the (mouseX, mouseY) to (lat, lng) and send it to the server which has to compute a route between current user's position to the clicked point. What we have We began writing a Java library with many useful maths to work with Rotation Matrices, Quaternions, Euler Angles, Translations, etc. We put it all together and created a program that generates sphere points, renders them and show them to the user inside a JPanel. We managed to catch clicks and translate them to spherical coords and to provide some other useful features like view rotation, scale, translation etc. What we have now is like a little (very little indeed) engine that simulates client and server interaction. Client side shows points on the screen and catches other interactions, server side renders the view and does other calculus like interpolating the route between current position and clicked point. Where is the problem? Obviously we want to have the shortest path to interpolate between the two route points. We use quaternions to interpolate between two points on the surface of the sphere and this seemed to work fine until i noticed that we weren't getting the shortest path on the sphere surface: We though the problem was that the route is calculated as the sum of two rotations about X and Y axis. So we changed the way we calculate the destination quaternion: We get the third angle (the first is latitude, the second is longitude, the third is the rotation about the vector which points toward our current position) which we called orientation. Now that we have the "orientation" angle we rotate Z axis and then use the result vector as the rotation axis for the destination quaternion (you can see the rotation axis in grey): What we got is the correct route (you can see it lays on a great circle), but we get to this ONLY if the starting route point is at latitude, longitude (0, 0) which means the starting vector is (sphereRadius, 0, 0). With the previous version (image 1) we don't get a good result even when startin point is 0, 0, so i think we're moving towards a solution, but the procedure we follow to get this route is a little "strange" maybe? In the following image you get a view of the problem we get when starting point is not (0, 0), as you can see starting point is not the (sphereRadius, 0, 0) vector, and as you can see the destination point (which is correctly drawn!) is not on the route. The magenta point (the one which lays on the route) is the route's ending point rotated about the center of the sphere of (-startLatitude, 0, -startLongitude). This means that if i calculate a rotation matrix and apply it to every point on the route maybe i'll get the real route, but I start to think that there's a better way to do this. Maybe I should try to get the plane through the center of the sphere and the route points, intersect it with the sphere and get the geodesic? But how? Sorry for being way too verbose and maybe for incorrect English but this thing is blowing my mind! EDIT: This code version is related to the first image: public void setRouteStart(double lat, double lng) { EulerAngles tmp = new EulerAngles ( Math.toRadians(lat), 0, -Math.toRadians(lng)); //set route start Quaternion qtStart.setInertialToObject(tmp); //do other stuff like drawing start point... } public void impostaDestinazione(double lat, double lng) { EulerAngles tmp = new AngoliEulero( Math.toRadians(lat), 0, -Math.toRadians(lng)); qtEnd.setInertialToObject(tmp); //do other stuff like drawing dest point... } public V3D interpolate(double totalTime, double t) { double _t = t/totalTime; Quaternion q = Quaternion.Slerp(qtStart, qtEnd, _t); RotationMatrix.inertialQuatToIObject(q); V3D p = matInt.inertialToObject(V3D.Xaxis.scale(sphereRadius)); //other stuff, like drawing point ... return p; } //mostly taken from a book! public static Quaternion Slerp(Quaternion q0, Quaternion q1, double t) { double cosO = q0.dot(q1); double q1w = q1.w; double q1x = q1.x; double q1y = q1.y; double q1z = q1.z; if (cosO < 0.0f) { q1w = -q1w; q1x = -q1x; q1y = -q1y; q1z = -q1z; cosO = -cosO; } double sinO = Math.sqrt(1.0f - cosO*cosO); double O = Math.atan2(sinO, cosO); double oneOverSinO = 1.0f / senoOmega; k0 = Math.sin((1.0f - t) * O) * oneOverSinO; k1 = Math.sin(t * O) * oneOverSinO; // Interpolate return new Quaternion( k0*q0.w + k1*q1w, k0*q0.x + k1*q1x, k0*q0.y + k1*q1y, k0*q0.z + k1*q1z ); } A little dump of what i get (again check image 1): Route info: Sphere radius and center: 200,000, (0.0, 0.0, 0.0) Route start: lat 0,000 °, lng 0,000 ° @v: (200,000, 0,000, 0,000), |v| = 200,000 Route end: lat 30,000 °, lng 30,000 ° @v: (150,000, 86,603, 100,000), |v| = 200,000 Qt dump: (w, x, y, z), rot. angle°, (x, y, z) rot. axis Qt start: (1,000, 0,000, -0,000, 0,000); 0,000 °; (1,000, 0,000, 0,000) Qt end: (0,933, 0,067, -0,250, 0,250); 42,181 °; (0,186, -0,695, 0,695) Route start: lat 30,000 °, lng 10,000 ° @v: (170,574, 30,077, 100,000), |v| = 200,000 Route end: lat 80,000 °, lng -50,000 ° @v: (22,324, -26,604, 196,962), |v| = 200,000 Qt dump: (w, x, y, z), rot. angle°, (x, y, z) rot. axis Qt start: (0,962, 0,023, -0,258, 0,084); 31,586 °; (0,083, -0,947, 0,309) Qt end: (0,694, -0,272, -0,583, -0,324); 92,062 °; (-0,377, -0,809, -0,450)

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  • Contracting as a Software Developer in the UK

    - by Frez
    Normal 0 false false false EN-GB X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;} Having had some 15 years’ experience of working as a software contractor, I am often asked by developers who work as permanent employees (permies) about the pros and cons of working as a software consultant through my own limited company and whether the move would be a good one for them. Whilst it is possible to contract using other financial vehicles such as umbrella companies, this article will only consider limited companies as that is what I have experience of using. Contracting or consultancy requires a different mind-set from being a permanent member of staff, and not all developers are capable of this shift in attitude. Whilst you can look forward to an increase in the money you take home, there are real risks and expenses you would not normally be exposed to as a permie. So let us have a look at the pros and cons: Pros: More money There is no doubt that whilst you are working on contracts you will earn significantly more than you would as a permanent employee. Furthermore, working through a limited company is more tax efficient. Less politics You really have no need to involve yourself in office politics. When the end of the day comes you can go home and not think or worry about the power struggles within the company you are contracted to. Your career progression is not tied to the company. Expenses from gross income All your expenses of trading as a business will come out of your company’s gross income, i.e. before tax. This covers travelling expenses provided you have not been at the same client/location for more than two years, internet subscriptions, professional subscriptions, software, hardware, accountancy services and so on. Cons: Work is more transient Contracts typically range from a couple of weeks to a year, although will most likely start at 3 months. However, most contracts are extended either because the project you have been brought in to help with takes longer to deliver than expected, the client decides they can use you on other aspects of the project, or the client decides they would like to use you on other projects. The temporary nature of the work means that you will have down-time between contracts while you secure new opportunities during which time your company will have no income. You may need to attend several interviews before securing a new contract. Accountancy expenses Your company is a separate entity and there are accountancy requirements which, unless you like paperwork, means your company will need to appoint an accountant to prepare your company’s accounts. It may also be worth purchasing some accountancy software, so talk to your accountant about this as they may prefer you to use a particular software package so they can integrate it with their systems. VAT You will need to register your company for VAT. This is tax neutral for you as the VAT you charge your clients you will pass onto the government less any VAT you are reclaiming from expenses, but it is additional paperwork to undertake each quarter. It is worth checking out the Fixed Rate VAT Scheme that is available, particularly after the initial expenses of setting up your company are over. No training Clients take you on based on your skills, not to train you when they will lose that investment at the end of the contract, so understand that it is unlikely you will receive any training funded by a client. However, learning new skills during a contract is possible and you may choose to accept a contract on a lower rate if this is guaranteed as it will help secure future contracts. No financial extras You will have no free pension, life, accident, sickness or medical insurance unless you choose to purchase them yourself. A financial advisor can give you all the necessary advice in this area, and it is worth taking seriously. A year after I started as a consultant I contracted a serious illness, this kept me off work for over two months, my client was very understanding and it could have been much worse, so it is worth considering what your options might be in the case of illness, death and retirement. Agencies Whilst it is possible to work directly for end clients there are pros and cons of working through an agency.  The main advantage is cash flow, you invoice the agency and they typically pay you within a week, whereas working directly for a client could have you waiting up to three months to be paid. The downside of working for agencies, especially in the current difficult times, is that they may go out of business and you then have difficulty getting the money you are owed. Tax investigation It is possible that the Inland Revenue may decide to investigate your company for compliance with tax law. Insurance is available to cover you for this. My personal recommendation would be to join the PCG as this insurance is included as a benefit of membership, Professional Indemnity Some agencies require that you are covered by professional indemnity insurance; this is a cost you would not incur as a permie. Travel Unless you live in an area that has an abundance of opportunities, such as central London, it is likely that you will be travelling further, longer and with more expense than if you were permanently employed at a local company. This not only affects you monetarily, but also your quality of life and the ability to keep fit and healthy. Obtaining finance If you want to secure a mortgage on a property it can be more difficult or expensive, especially if you do not have three years of audited accounts to show a mortgage lender.   Caveat This post is my personal opinion and should not be used as a definitive guide or recommendation to contracting and whether it is suitable for you as an individual, i.e. I accept no responsibility if you decide to take up contracting based on this post and you fare badly for whatever reason.

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  • SQL University: What and why of database testing

    - by Mladen Prajdic
    This is a post for a great idea called SQL University started by Jorge Segarra also famously known as SqlChicken on Twitter. It’s a collection of blog posts on different database related topics contributed by several smart people all over the world. So this week is mine and we’ll be talking about database testing and refactoring. In 3 posts we’ll cover: SQLU part 1 - What and why of database testing SQLU part 2 - What and why of database refactoring SQLU part 2 – Tools of the trade With that out of the way let us sharpen our pencils and get going. Why test a database The sad state of the industry today is that there is very little emphasis on testing in general. Test driven development is still a small niche of the programming world while refactoring is even smaller. The cause of this is the inability of developers to convince themselves and their managers that writing tests is beneficial. At the moment they are mostly viewed as waste of time. This is because the average person (let’s not fool ourselves, we’re all average) is unable to think about lower future costs in relation to little more current work. It’s orders of magnitude easier to know about the current costs in relation to current amount of work. That’s why programmers convince themselves testing is a waste of time. However we have to ask ourselves what tests are really about? Maybe finding bugs? No, not really. If we introduce bugs, we’re likely to write test around those bugs too. But yes we can find some bugs with tests. The main point of tests is to have reproducible repeatability in our systems. By having a code base largely covered by tests we can know with better certainty what a small code change can break in other parts of the system. By having repeatability we can make code changes with confidence, since we know we’ll see what breaks in other tests. And here comes the inability to estimate future costs. By spending just a few more hours writing those tests we’d know instantly what broke where. Imagine we fix a reported bug. We check-in the code, deploy it and the users are happy. Until we get a call 2 weeks later about a certain monthly process has stopped working. What we don’t know is that this process was developed by a long gone coworker and for some reason it relied on that same bug we’ve happily fixed. There’s no way we could’ve known that. We say OK and go in and fix the monthly process. But what we have no clue about is that there’s this ETL job that relied on data from that monthly process. Now that we’ve fixed the process it’s giving unexpected (yet correct since we fixed it) data to the ETL job. So we have to fix that too. But there’s this part of the app we coded that relies on data from that exact ETL job. And just like that we enter the “Loop of maintenance horror”. With the loop eventually comes blame. Here’s a nice tip for all developers and DBAs out there: If you make a mistake man up and admit to it. All of the above is valid for any kind of software development. Keeping this in mind the database is nothing other than just a part of the application. But a big part! One reason why testing a database is even more important than testing an application is that one database is usually accessed from multiple applications and processes. This makes it the central and vital part of the enterprise software infrastructure. Knowing all this can we really afford not to have tests? What to test in a database Now that we’ve decided we’ll dive into this testing thing we have to ask ourselves what needs to be tested? The short answer is: everything. The long answer is: read on! There are 2 main ways of doing tests: Black box and White box testing. Black box testing means we have no idea how the system internals are built and we only have access to it’s inputs and outputs. With it we test that the internal changes to the system haven’t caused the input/output behavior of the system to change. The most important thing to test here are the edge conditions. It’s where most programs break. Having good edge condition tests we can be more confident that the systems changes won’t break. White box testing has the full knowledge of the system internals. With it we test the internal system changes, different states of the application, etc… White and Black box tests should be complementary to each other as they are very much interconnected. Testing database routines includes testing stored procedures, views, user defined functions and anything you use to access the data with. Database routines are your input/output interface to the database system. They count as black box testing. We test then for 2 things: Data and schema. When testing schema we only care about the columns and the data types they’re returning. After all the schema is the contract to the out side systems. If it changes we usually have to change the applications accessing it. One helpful T-SQL command when doing schema tests is SET FMTONLY ON. It tells the SQL Server to return only empty results sets. This speeds up tests because it doesn’t return any data to the client. After we’ve validated the schema we have to test the returned data. There no other way to do this but to have expected data known before the tests executes and comparing that data to the database routine output. Testing Authentication and Authorization helps us validate who has access to the SQL Server box (Authentication) and who has access to certain database objects (Authorization). For desktop applications and windows authentication this works well. But the biggest problem here are web apps. They usually connect to the database as a single user. Please ensure that that user is not SA or an account with admin privileges. That is just bad. Load testing ensures us that our database can handle peak loads. One often overlooked tool for load testing is Microsoft’s OSTRESS tool. It’s part of RML utilities (x86, x64) for SQL Server and can help determine if our database server can handle loads like 100 simultaneous users each doing 10 requests per second. SQL Profiler can also help us here by looking at why certain queries are slow and what to do to fix them.   One particular problem to think about is how to begin testing existing databases. First thing we have to do is to get to know those databases. We can’t test something when we don’t know how it works. To do this we have to talk to the users of the applications accessing the database, run SQL Profiler to see what queries are being run, use existing documentation to decipher all the object relationships, etc… The way to approach this is to choose one part of the database (say a logical grouping of tables that go together) and filter our traces accordingly. Once we’ve done that we move on to the next grouping and so on until we’ve covered the whole database. Then we move on to the next one. Database Testing is a topic that we can spent many hours discussing but let this be a nice intro to the world of database testing. See you in the next post.

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  • More Great Improvements to the Windows Azure Management Portal

    - by ScottGu
    Over the last 3 weeks we’ve released a number of enhancements to the new Windows Azure Management Portal.  These new capabilities include: Localization Support for 6 languages Operation Log Support Support for SQL Database Metrics Virtual Machine Enhancements (quick create Windows + Linux VMs) Web Site Enhancements (support for creating sites in all regions, private github repo deployment) Cloud Service Improvements (deploy from storage account, configuration support of dedicated cache) Media Service Enhancements (upload, encode, publish, stream all from within the portal) Virtual Networking Usability Enhancements Custom CNAME support with Storage Accounts All of these improvements are now live in production and available to start using immediately.  Below are more details on them: Localization Support The Windows Azure Portal now supports 6 languages – English, German, Spanish, French, Italian and Japanese. You can easily switch between languages by clicking on the Avatar bar on the top right corner of the Portal: Selecting a different language will automatically refresh the UI within the portal in the selected language: Operation Log Support The Windows Azure Portal now supports the ability for administrators to review the “operation logs” of the services they manage – making it easy to see exactly what management operations were performed on them.  You can query for these by selecting the “Settings” tab within the Portal and then choosing the “Operation Logs” tab within it.  This displays a filter UI that enables you to query for operations by date and time: As of the most recent release we now show logs for all operations performed on Cloud Services and Storage Accounts.  You can click on any operation in the list and click the “Details” button in the command bar to retrieve detailed status about it.  This now makes it possible to retrieve details about every management operation performed. In future updates you’ll see us extend the operation log capability to apply to all Windows Azure Services – which will enable great post-mortem and audit support. Support for SQL Database Metrics You can now monitor the number of successful connections, failed connections and deadlocks in your SQL databases using the new “Dashboard” view provided on each SQL Database resource: Additionally, if the database is added as a “linked resource” to a Web Site or Cloud Service, monitoring metrics for the linked SQL database are shown along with the Web Site or Cloud Service metrics in the dashboard. This helps with viewing and managing aggregated information across both resources in your application. Enhancements to Virtual Machines The most recent Windows Azure Portal release brings with it some nice usability improvements to Virtual Machines: Integrated Quick Create experience for Windows and Linux VMs Creating a new Windows or Linux VM is now easy using the new “Quick Create” experience in the Portal: In addition to Windows VM templates you can also now select Linux image templates in the quick create UI: This makes it incredibly easy to create a new Virtual Machine in only a few seconds. Enhancements to Web Sites Prior to this past month’s release, users were forced to choose a single geographical region when creating their first site.  After that, subsequent sites could only be created in that same region.  This restriction has now been removed, and you can now create sites in any region at any time and have up to 10 free sites in each supported region: One of the new regions we’ve recently opened up is the “East Asia” region.  This allows you to now deploy sites to North America, Europe and Asia simultaneously.  Private GitHub Repository Support This past week we also enabled Git based continuous deployment support for Web Sites from private GitHub and BitBucket repositories (previous to this you could only enable this with public repositories).  Enhancements to Cloud Services Experience The most recent Windows Azure Portal release brings with it some nice usability improvements to Cloud Services: Deploy a Cloud Service from a Windows Azure Storage Account The Windows Azure Portal now supports deploying an application package and configuration file stored in a blob container in Windows Azure Storage. The ability to upload an application package from storage is available when you custom create, or upload to, or update a cloud service deployment. To upload an application package and configuration, create a Cloud Service, then select the file upload dialog, and choose to upload from a Windows Azure Storage Account: To upload an application package from storage, click the “FROM STORAGE” button and select the application package and configuration file to use from the new blob storage explorer in the portal. Configure Windows Azure Caching in a caching enabled cloud service If you have deployed the new dedicated cache within a cloud service role, you can also now configure the cache settings in the portal by navigating to the configuration tab of for your Cloud Service deployment. The configuration experience is similar to the one in Visual Studio when you create a cloud service and add a caching role.  The portal now allows you to add or remove named caches and change the settings for the named caches – all from within the Portal and without needing to redeploy your application. Enhancements to Media Services You can now upload, encode, publish, and play your video content directly from within the Windows Azure Portal.  This makes it incredibly easy to get started with Windows Azure Media Services and perform common tasks without having to write any code. Simply navigate to your media service and then click on the “Content” tab.  All of the media content within your media service account will be listed here: Clicking the “upload” button within the portal now allows you to upload a media file directly from your computer: This will cause the video file you chose from your local file-system to be uploaded into Windows Azure.  Once uploaded, you can select the file within the content tab of the Portal and click the “Encode” button to transcode it into different streaming formats: The portal includes a number of pre-set encoding formats that you can easily convert media content into: Once you select an encoding and click the ok button, Windows Azure Media Services will kick off an encoding job that will happen in the cloud (no need for you to stand-up or configure a custom encoding server).  When it’s finished, you can select the video in the “Content” tab and then click PUBLISH in the command bar to setup an origin streaming end-point to it: Once the media file is published you can point apps against the public URL and play the content using Windows Azure Media Services – no need to setup or run your own streaming server.  You can also now select the file and click the “Play” button in the command bar to play it using the streaming endpoint directly within the Portal: This makes it incredibly easy to try out and use Windows Azure Media Services and test out an end-to-end workflow without having to write any code.  Once you test things out you can of course automate it using script or code – providing you with an incredibly powerful Cloud Media platform that you can use. Enhancements to Virtual Network Experience Over the last few months, we have received feedback on the complexity of the Virtual Network creation experience. With these most recent Portal updates, we have added a Quick Create experience that makes the creation experience very simple. All that an administrator now needs to do is to provide a VNET name, choose an address space and the size of the VNET address space. They no longer need to understand the intricacies of the CIDR format or walk through a 4-page wizard or create a VNET / subnet. This makes creating virtual networks really simple: The portal also now has a “Register DNS Server” task that makes it easy to register DNS servers and associate them with a virtual network. Enhancements to Storage Experience The portal now lets you register custom domain names for your Windows Azure Storage Accounts.  To enable this, select a storage resource and then go to the CONFIGURE tab for a storage account, and then click MANAGE DOMAIN on the command bar: Clicking “Manage Domain” will bring up a dialog that allows you to register any CNAME you want: Summary The above features are all now live in production and available to use immediately.  If you don’t already have a Windows Azure account, you can sign-up for a free trial and start using them today.  Visit the Windows Azure Developer Center to learn more about how to build apps with it. One of the other cool features that is now live within the portal is our new Windows Azure Store – which makes it incredibly easy to try and purchase developer services from a variety of partners.  It is an incredibly awesome new capability – and something I’ll be doing a dedicated post about shortly. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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  • Big Visible Charts

    - by Robert May
    An important part of Agile is the concept of transparency and visibility. In proper functioning teams, stakeholders can look at any team at any time in the iteration or release and see how that team is doing by simply looking at what we call Big Visible Charts. If you’ve done Scrum, you’ve seen these charts. However, interpreting these charts can often be an art form. There are several different charts that can be useful. In this newsletter, I’ll focus on the Iteration Burndown and Cumulative Flow charts. I’ve included a copy of the spreadsheet that I used to create the charts, and if you don’t have a tool that creates them for you, you can use this spreadsheet to do so. Our preferred tool for managing Scrum projects is Rally. Rally creates all of these charts for you, saving you quite a bit of time. The Iteration Burndown and Cumulative Flow Charts This is the main chart that teams use. Although less useful to stakeholders, this chart is critical to the team and provides quite a bit of information to the team about how their iteration is going. Most charts are a combination of the charts below, so you may need to combine aspects of each section to understand what is happening in your iterations. Ideal Ah, isn’t that a pretty picture? Unfortunately, it’s also very unrealistic. I’ve seen iterations that come close to ideal, but never that match perfectly. If your iteration matches perfectly, chances are, someone is playing with the numbers. Reality is just too difficult to have a burndown chart that matches this exactly. Late Planning Iteration started, but the team didn’t. You can tell this by the fact that the real number of estimated hours didn’t appear until day two. In the cumulative flow, you can also see that nothing was defined in Day one and two. You want to avoid situations like this. You’ll note that the team had to burn faster than is ideal to meet the iteration because of the late planning. This often results in long weeks and days. Testing Starved Determining whether or not testing is starved is difficult without the cumulative flow. The pattern in the burndown could be nothing more that developers not completing stories early enough or could be caused by stories being too big. With the cumulative flow, however, you see that only small bites are in progress and stories were completed early, but testing didn’t start testing until the end of the iteration, and didn’t complete testing all stories in the iteration. When this happens, question whether or not your testing resources are sufficient for your team and whether or not acceptance is adequately defined. No Testing With this one, both graphs show the same thing; the team needs testers and testing! Without testing, what was completed cannot be verified to make sure that it is acceptable to the business. If you find yourself in this situation, review your testing practices and acceptance testing process and make changes today. Late Development With this situation, both graphs tell a story. In the top graph, you can see that the hours failed to burn down as quickly as the team expected. This could be caused by the team not correctly estimating their hours or the team could have had illness or some other issue that affected them. Often, when teams are tackling something that is more unknown, they’ll run into technical barriers that cause the burn down to happen slower than expected. In the cumulative flow graph, you can see that not much was completed in the first few days. This could be because of illness or technical barriers or simply poor estimation. Testing was able to keep up with everything that was completed, however. No Tool Updating When you see graphs that look like this, you can be assured that it’s because the team is not updating the tool that generates the graphs. Review your policy for when they are to update. On the teams that I run, I require that each team member updates the tool at least once daily. You should also check to see how well the team is breaking down stories into tasks. If they’re creating few large tasks, graphs can look similar to this. As a general rule, I never allow tasks, other than Unit Testing and Uncertainty, to be greater than eight hours in duration. Scope Increase I always encourage team members to enter in however much time they think they have left on a task, even if that means increasing the total amount of time left to do. You get a much better and more realistic picture this way. Increasing time remaining could explain the burndown graph, but by looking at the cumulative flow graph, we can see that stories were added to the iteration and scope was increased. Since planning should consume all of the hours in the iteration, this is almost always a bad thing. If the scope change happened late in the iteration and the hours remaining were well below the ideal burn, then increasing scope is probably o.k., but estimation needs to get better. However, with the charts above, that’s clearly not what happened and the team was required to do extra work to make the iteration. If you find this happening, your product owner and ScrumMasters need training. The team also needs to learn to say no. Scope Decrease Scope decreases are just as bad as scope increases. Usually, graphs above show that the team did a poor job of estimating their stories and part way through had to reduce scope to change the iteration. This will happen once in a while, but if you find it’s a pattern on your team, you need to re-evaluate planning. Some teams are hopelessly optimistic. In those cases, I’ll introduce a task I call “Uncertainty.” With Uncertainty, the team estimates how many hours they might need if things don’t go well with the tasks they’ve defined. They try to estimate things that could go poorly and increase the time appropriately. Having an Uncertainty task allows them to have a low and high estimate. Uncertainty should not just be an arbitrary buffer. It must correlate to real uncertainty in the tasks that have been defined. Stories are too Big Often, we see graphs like the ones above. Note that the burndown looks fairly good, other than the chunky acceptance of stories. However, when you look at cumulative flow, you can see that at one point, everything is in progress. This is a bad thing. When you see graphs like this, you’re in one of two states. You may just have a very small team and can only handle one or two stories in your iteration. If you have more than one or two people, then the most likely problem is that your stories are far too big. To combat this, break large high hour stories into smaller pieces that can be completed independently and accepted independently. If you don’t, you’ll likely be requiring your testers to do heroic things to complete testing on the last day of the iteration and you’re much more likely to have the entire iteration fail, because of the limited amount of things that can be completed. Summary There are other charts that can be useful when doing scrum. If you don’t have any big visible charts, you really need to evaluate your process and change. These charts can provide the team a wealth of information and help you write better software. If you have any questions about charts that you’re seeing on your team, contact me with a screen capture of the charts and I’ll tell you what I’m seeing in those charts. I always want this information to be useful, so please let me know if you have other questions. Technorati Tags: Agile

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  • DBCC CHECKDB on VVLDB and latches (Or: My Pain is Your Gain)

    - by Argenis
      Does your CHECKDB hurt, Argenis? There is a classic blog series by Paul Randal [blog|twitter] called “CHECKDB From Every Angle” which is pretty much mandatory reading for anybody who’s even remotely considering going for the MCM certification, or its replacement (the Microsoft Certified Solutions Master: Data Platform – makes my fingers hurt just from typing it). Of particular interest is the post “Consistency Options for a VLDB” – on it, Paul provides solid, timeless advice (I use the word “timeless” because it was written in 2007, and it all applies today!) on how to perform checks on very large databases. Well, here I was trying to figure out how to make CHECKDB run faster on a restored copy of one of our databases, which happens to exceed 7TB in size. The whole thing was taking several days on multiple systems, regardless of the storage used – SAS, SATA or even SSD…and I actually didn’t pay much attention to how long it was taking, or even bothered to look at the reasons why - as long as it was finishing okay and found no consistency errors. Yes – I know. That was a huge mistake, as corruption found in a database several days after taking place could only allow for further spread of the corruption – and potentially large data loss. In the last two weeks I increased my attention towards this problem, as we noticed that CHECKDB was taking EVEN LONGER on brand new all-flash storage in the SAN! I couldn’t really explain it, and were almost ready to blame the storage vendor. The vendor told us that they could initially see the server driving decent I/O – around 450Mb/sec, and then it would settle at a very slow rate of 10Mb/sec or so. “Hum”, I thought – “CHECKDB is just not pushing the I/O subsystem hard enough”. Perfmon confirmed the vendor’s observations. Dreaded @BlobEater What was CHECKDB doing all the time while doing so little I/O? Eating Blobs. It turns out that CHECKDB was taking an extremely long time on one of our frankentables, which happens to be have 35 billion rows (yup, with a b) and sucks up several terabytes of space in the database. We do have a project ongoing to purge/split/partition this table, so it’s just a matter of time before we deal with it. But the reality today is that CHECKDB is coming to a screeching halt in performance when dealing with this particular table. Checking sys.dm_os_waiting_tasks and sys.dm_os_latch_stats showed that LATCH_EX (DBCC_OBJECT_METADATA) was by far the top wait type. I remembered hearing recently about that wait from another post that Paul Randal made, but that was related to computed-column indexes, and in fact, Paul himself reminded me of his article via twitter. But alas, our pathologic table had no non-clustered indexes on computed columns. I knew that latches are used by the database engine to do internal synchronization – but how could I help speed this up? After all, this is stuff that doesn’t have a lot of knobs to tweak. (There’s a fantastic level 500 talk by Bob Ward from Microsoft CSS [blog|twitter] called “Inside SQL Server Latches” given at PASS 2010 – and you can check it out here. DISCLAIMER: I assume no responsibility for any brain melting that might ensue from watching Bob’s talk!) Failed Hypotheses Earlier on this week I flew down to Palo Alto, CA, to visit our Headquarters – and after having a great time with my Monkey peers, I was relaxing on the plane back to Seattle watching a great talk by SQL Server MVP and fellow MCM Maciej Pilecki [twitter] called “Masterclass: A Day in the Life of a Database Transaction” where he discusses many different topics related to transaction management inside SQL Server. Very good stuff, and when I got home it was a little late – that slow DBCC CHECKDB that I had been dealing with was way in the back of my head. As I was looking at the problem at hand earlier on this week, I thought “How about I set the database to read-only?” I remembered one of the things Maciej had (jokingly) said in his talk: “if you don’t want locking and blocking, set the database to read-only” (or something to that effect, pardon my loose memory). I immediately killed the CHECKDB which had been running painfully for days, and set the database to read-only mode. Then I ran DBCC CHECKDB against it. It started going really fast (even a bit faster than before), and then throttled down again to around 10Mb/sec. All sorts of expletives went through my head at the time. Sure enough, the same latching scenario was present. Oh well. I even spent some time trying to figure out if NUMA was hurting performance. Folks on Twitter made suggestions in this regard (thanks, Lonny! [twitter]) …Eureka? This past Friday I was still scratching my head about the whole thing; I was ready to start profiling with XPERF to see if I could figure out which part of the engine was to blame and then get Microsoft to look at the evidence. After getting a bunch of good news I’ll blog about separately, I sat down for a figurative smack down with CHECKDB before the weekend. And then the light bulb went on. A sparse column. I thought that I couldn’t possibly be experiencing the same scenario that Paul blogged about back in March showing extreme latching with non-clustered indexes on computed columns. Did I even have a non-clustered index on my sparse column? As it turns out, I did. I had one filtered non-clustered index – with the sparse column as the index key (and only column). To prove that this was the problem, I went and setup a test. Yup, that'll do it The repro is very simple for this issue: I tested it on the latest public builds of SQL Server 2008 R2 SP2 (CU6) and SQL Server 2012 SP1 (CU4). First, create a test database and a test table, which only needs to contain a sparse column: CREATE DATABASE SparseColTest; GO USE SparseColTest; GO CREATE TABLE testTable (testCol smalldatetime SPARSE NULL); GO INSERT INTO testTable (testCol) VALUES (NULL); GO 1000000 That’s 1 million rows, and even though you’re inserting NULLs, that’s going to take a while. In my laptop, it took 3 minutes and 31 seconds. Next, we run DBCC CHECKDB against the database: DBCC CHECKDB('SparseColTest') WITH NO_INFOMSGS, ALL_ERRORMSGS; This runs extremely fast, as least on my test rig – 198 milliseconds. Now let’s create a filtered non-clustered index on the sparse column: CREATE NONCLUSTERED INDEX [badBadIndex] ON testTable (testCol) WHERE testCol IS NOT NULL; With the index in place now, let’s run DBCC CHECKDB one more time: DBCC CHECKDB('SparseColTest') WITH NO_INFOMSGS, ALL_ERRORMSGS; In my test system this statement completed in 11433 milliseconds. 11.43 full seconds. Quite the jump from 198 milliseconds. I went ahead and dropped the filtered non-clustered indexes on the restored copy of our production database, and ran CHECKDB against that. We went down from 7+ days to 19 hours and 20 minutes. Cue the “Argenis is not impressed” meme, please, Mr. LaRock. My pain is your gain, folks. Go check to see if you have any of such indexes – they’re likely causing your consistency checks to run very, very slow. Happy CHECKDBing, -Argenis ps: I plan to file a Connect item for this issue – I consider it a pretty serious bug in the engine. After all, filtered indexes were invented BECAUSE of the sparse column feature – and it makes a lot of sense to use them together. Watch this space and my twitter timeline for a link.

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  • Windows Phone Developer Spotlight: Nikolai Joukov

    - by Lori Lalonde
    Originally posted on: http://geekswithblogs.net/lorilalonde/archive/2014/06/04/windows-phone-developer-spotlight-nikolai-joukov.aspxAs part of an ongoing series, I plan to include a spotlight post on people within the community that are stars in their field and area of expertise. For my first spotlight post, I interviewed Nikolai Joukov, who is a regular attendee at my local area .NET User Group (CTTDNUG), and has also participated in many of the Mobile and Cloud workshops we have hosted over the past few years. Nikolai stood out immediately, because of his passion for developing mobile apps, his interest in continuous learning, and his drive to publish quality apps that people will find useful and entertaining. Background: Nikolai immigrated to Canada in 1995, and has been working in IT since 1997. He moved on to become an independent contractor in 2005, and has worked at various large scale organizations over the course of his career, including BMO, Enbridge, Economical Insurance, Equitable Life, Manulife and Sun Life. Nikolai is an accomplished Windows Phone and Windows Store publisher, with 11 published Windows Phone apps, and 8 published Windows Store apps. He has almost 6000 downloads and favourable reviews. Q & A with Nikolai How many years have you been developing Windows Phone apps? 2 years When did you develop your very first Windows Phone app, and what was it about? Actually, the very first app I wrote was for the Microsoft “Smart Phone” back in 2004. This phone was given to me by Microsoft during the Developers Days Conference in Toronto. It was some kind of experimental model named Smart Phone, but you had to use VB 3 to develop the applications. Needless to say, this was not very successful at that time. My app was a Stock Trades Calculator. Very primitive, but it was working for me. The phone was heavy and the battery barely lasted 4 hours. Microsoft stopped supporting it few months later and the phone stopped working shortly after, but I still have it as a souvenir. For Windows Phone, my first app was “Trip Packing Assistant”. This is a simple trip packing check list that allows you to list items by category, set required quantity of items, and mark off the item in the list when it is packed. I designed it for me and my wife Galina, since we love to travel and this program helps manage our list for us. How did you get started in Windows Phone development? I have to say thanks to our .NET User Group for introducing me to Windows Phone development. I was intrigued and decided to give it a try. In October 2012 during a 2 day training event that ObjectSharp hosted in London, I met Bruce Johnson. On his advice, I registered for Developer Movement, and it is was a good push to actually complete the apps that I started. You have a great series of travel guide apps both for Windows Phone and Windows Store. Tell us about how you came up with the idea to develop those apps and what process you went through to put it all together. Like I said earlier, my wife and I love to travel. Before I created Trip Packing Assistant, every time we were planning to travel somewhere new, Galina would spend 3-4 weeks doing research. She would create a Word document with all of the information. We didn’t want to have to carry our laptop with us all the time, so we printed out the Word document she created, and would take it with us. After we returned from the trip, we would bring back tons of pictures and materials. Then our friends started to ask us about our materials before they planned their trips to the same places we had visited. So I decided to give it a try and started making apps for Windows Phone and for Windows 8. I hope these applications will help people who are planning to travel. So, all of the pictures used in the travel apps you created were actually taken by you during these amazing trips? Yes Do you have another Windows Store/Windows Phone project in development right now? If so, can you give us a hint at what it will be about? I want to stay with travel apps for now. But this time I will try to write an app for us (Galina and I). Usually we go on the trip, then I write the apps after we have all this beautiful pictures in our hands. We are planning a trip to Rome. This app will not have the pictures, but I want to add a map with points of interest and all information that can be useful for us. Then we will go on our trip and test it on location. As well I am planning to work on my existing apps to make them better. What learning resources would you recommend for other developers that want to get started in Window Store and Windows Phone development? I would start with dev.windowsphone.com to get all tools and samples, also links to training materials. I like MVA (Microsoft Virtual Academy). Their videos are really useful and it is free. Pluralsight is good too but it is not free and I do not have a subscription anymore. Our .NET User Group meetings give good insights too. I went to all meetings and full day training events. When you start to develop your app, you need to do research for specific questions that arise during development. The Developer Portal and Nokia Developer are good resources too. Wrap Up Thanks Nikolai for participating in my first Spotlight blog post! Shown below is Nikolai’s publisher page in the Windows Phone Store and his publisher page in the Windows Store. Simply click on it to be taken to there to check out his portfolio of apps. Be sure to download his apps and try them out! They are all free! Nikolai’s Windows Phone apps   Nikolai’s Windows Store Apps

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  • Mobile BI Comes of Age

    - by rich.clayton(at)oracle.com
    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-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} 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-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} One of the hot topics in the Business Intelligence industry is mobility.  More specifically the question is how business can be transformed by the iPhone and the iPad.  In June 2003, Gartner predicted that Mobile BI would be obsolete and that the technology was headed for the 'trough of disillusionment'.  I agreed with them at that time.  Many vendors like MicroStrategy and Business Objects jumped into the fray attempting to show how PDA's like Palm Pilots could be integrated with BI.  Their investments resulted in interesting demos with no commercial traction.  Why, because wireless networks and mobile operating systems were primitive, immature and slow. In my opinion, Apple's iOS has changed everything in Mobile BI.  Yes Blackberry, Android and Symbian and all the rest have their place in the market but I believe that increasingly consumers (not IT departments) influence BI decision making processes.  Consumers are choosing the iPhone and the iPad. The number of iPads I see in business meetings now is staggering.  Some use it for email and note taking and others are starting to use corporate applications.  The possibilities for Mobile BI are countless and I would expect to see iPads enterprise-wide over the next few years.   These new devices will provide just-in-time access to critical business information.  Front-line managers interacting with customers, suppliers, patients or citizens will have information literally at their fingertips. I've experimented with several mobile BI tools.  They look cool but like their Executive Information System (EIS) predecessors of the 1990's these tools lack a backbone and a plausible integration strategy.  EIS was a viral technology in the early 1990's.  Executives from every industry and job function were showcasing their dashboards to fellow co-workers and colleagues at the country club.  Just like the iPad, every senior manager wanted one.  EIS wasn't a device however, it was a software application.   EIS quickly faded into the software sunset as it lacked integration with corporate information systems.  BI servers  replaced EIS because the technology focused on the heavy data lifting of integrating, normalizing, aggregating and managing large, complex data volumes.  The devices are here to stay. The cute stand-alone mobile BI tools, not so much. If all you're looking to do is put Excel files on your iPad, there are plenty of free tools on the market.  You'll look cool at your next management meeting but after a few weeks, the cool factor will fade away and you'll be wondering how you will ever maintain it.  If however you want secure, consistent, reliable information on your iPad, you need an integration strategy and a way to model the data.  BI Server technologies like the Oracle BI Foundation is a market leading approach to tackle that issue. I liken the BI mobility frenzy to buying classic cars.  Classic Cars have two buying groups - teenagers and middle-age folks looking to tinker.  Teenagers look at the pin-stripes and the paint job while middle-agers (like me)  kick the tires a bit and look under the hood to check out the quality and reliability of the engine.  Mobile BI tools sure look sexy but don't go very far without an engine and a transmission or an integration strategy. The strategic question in Mobile BI is can these startups build a motor and transmission faster than Oracle can re-paint the car?  Oracle has a great engine and a transmission that connects to all enterprise information assets.  We're working on the new paint job and are excited about the possibilities.  Just as vertical integration worked in the automotive business, it too works in the technology industry.

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  • SQL Sentry First Impressions

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

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  • Building an Infrastructure Cloud with Oracle VM for x86 + Enterprise Manager 12c

    - by Richard Rotter
    Cloud Computing? Everyone is talking about Cloud these days. Everyone is explaining how the cloud will help you to bring your service up and running very fast, secure and with little effort. You can find these kinds of presentations at almost every event around the globe. But what is really behind all this stuff? Is it really so simple? And the answer is: Yes it is! With the Oracle SW Stack it is! In this post, I will try to bring this down to earth, demonstrating how easy it could be to build a cloud infrastructure with Oracle's solution for cloud computing.But let me cover some basics first: How fast can you build a cloud?How elastic is your cloud so you can provide new services on demand? How much effort does it take to monitor and operate your Cloud Infrastructure in order to meet your SLAs?How easy is it to chargeback for your services provided? These are the critical success factors of Cloud Computing. And Oracle has an answer to all those questions. By using Oracle VM for X86 in combination with Enterprise Manager 12c you can build and control your cloud environment very fast and easy. What are the fundamental building blocks for your cloud? Oracle Cloud Building Blocks #1 Hardware Surprise, surprise. Even the cloud needs to run somewhere, hence you will need hardware. This HW normally consists of servers, storage and networking. But Oracles goes beyond that. There are Optimized Solutions available for your cloud infrastructure. This is a cookbook to build your HW cloud platform. For example, building your cloud infrastructure with blades and our network infrastructure will reduce complexity in your datacenter (Blades with switch network modules, splitter cables to reduce the amount of cables, TOR (Top Of the Rack) switches which are building the interface to your infrastructure environment. Reducing complexity even in the cabling will help you to manage your environment more efficient and with less risk. Of course, our engineered systems fit into the cloud perfectly too. Although they are considered as a PaaS themselves, having the database SW (for Exadata) and the application development environment (for Exalogic) already deployed on them, in general they are ideal systems to enable you building your own cloud and PaaS infrastructure. #2 Virtualization The next missing link in the cloud setup is virtualization. For me personally, it's one of the most hidden "secret", that oracle can provide you with a complete virtualization stack in terms of a hypervisor on both architectures: X86 and Sparc CPUs. There is Oracle VM for X86 and Oracle VM for Sparc available at no additional  license costs if your are running this virtualization stack on top of Oracle HW (and with Oracle Premier Support for HW). This completes the virtualization portfolio together with Solaris Zones introduced already with Solaris 10 a few years ago. Let me explain how Oracle VM for X86 works: Oracle VM for x86 consists of two main parts: - The Oracle VM Server: Oracle VM Server is installed on bare metal and it is the hypervisor which is able to run virtual machines. It has a very small footprint. The ISO-Image of Oracle VM Server is only 200MB large. It is very small but efficient. You can install a OVM-Server in less than 5 mins by booting the Server with the ISO-Image assigned and providing the necessary configuration parameters (like installing an Linux distribution). After the installation, the OVM-Server is ready to use. That's all. - The Oracle VM-Manager: OVM-Manager is the central management tool where you can control your OVM-Servers. OVM-Manager provides the graphical user interface, which is an Application Development Framework (ADF) application, with a familiar web-browser based interface, to manage Oracle VM Servers, virtual machines, and resources. The Oracle VM Manager has the following capabilities: Create virtual machines Create server pools Power on and off virtual machines Manage networks and storage Import virtual machines, ISO files, and templates Manage high availability of Oracle VM Servers, server pools, and virtual machines Perform live migration of virtual machines I want to highlight one of the goodies which you can use if you are running Oracle VM for X86: Preconfigured, downloadable Virtual Machine Templates form edelivery With these templates, you can download completely preconfigured Virtual Machines in your environment, boot them up, configure them at first time boot and use it. There are templates for almost all Oracle SW and Applications (like Fusion Middleware, Database, Siebel, etc.) available. #3) Cloud Management The management of your cloud infrastructure is key. This is a day-to-day job. Acquiring HW, installing a virtualization layer on top of it is done just at the beginning and if you want to expand your infrastructure. But managing your cloud, keeping it up and running, deploying new services, changing your chargeback model, etc, these are the daily jobs. These jobs must be simple, secure and easy to manage. The Enterprise Manager 12c Cloud provides this functionality from one management cockpit. Enterprise Manager 12c uses Oracle VM Manager to control OVM Serverpools. Once you registered your OVM-Managers in Enterprise Manager, then you are able to setup your cloud infrastructure and manage everything from Enterprise Manager. What you need to do in EM12c is: ">Register your OVM Manager in Enterprise ManagerAfter Registering your OVM Manager, all the functionality of Oracle VM for X86 is also available in Enterprise Manager. Enterprise Manager works as a "Manger" of the Manager. You can register as many OVM-Managers you want and control your complete virtualization environment Create Roles and Users for your Self Service Portal in Enterprise ManagerWith this step you allow users to logon on the Enterprise Manager Self Service Portal. Users can request Virtual Machines in this portal. Setup the Cloud InfrastructureSetup the Quotas for your self service users. How many VMs can they request? How much of your resources ( cpu, memory, storage, network, etc. etc.)? Which SW components (templates, assemblys) can your self service users request? In this step, you basically set up the complete cloud infrastructure. Setup ChargebackOnce your cloud is set up, you need to configure your chargeback mechanism. The Enterprise Manager collects the resources metrics, which are used in a very deep level. Almost all collected Metrics could be used in the chargeback module. You can define chargeback plans based on configurations (charge for the amount of cpu, memory, storage is assigned to a machine, or for a specific OS which is installed) or chargeback on resource consumption (% of cpu used, storage used, etc). Or you can also define a combination of configuration and consumption chargeback plans. The chargeback module is very flexible. Here is a overview of the workflow how to handle infrastructure cloud in EM: Summary As you can see, setting up an Infrastructure Cloud Service with Oracle VM for X86 and Enterprise Manager 12c is really simple. I personally configured a complete cloud environment with three X86 servers and a small JBOD san box in less than 3 hours. There is no magic in it, it is all straightforward. Of course, you have to have some experience with Oracle VM and Enterprise Manager. Experience in setting up Linux environments helps as well. I plan to publish a technical cookbook in the next few weeks. I hope you found this post useful and will see you again here on our blog. Any hints, comments are welcome!

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  • Christmas in the Clouds

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

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  • Developing Schema Compare for Oracle (Part 1)

    - by Simon Cooper
    SQL Compare is one of Red Gate's most successful SQL Server tools; it allows developers and DBAs to compare and synchronize the contents of their databases. Although similar tools exist for Oracle, they are quite noticeably lacking in the usability and stability that SQL Compare is known for in the SQL Server world. We could see a real need for a usable schema comparison tools for Oracle, and so the Schema Compare for Oracle project was born. Over the next few weeks, as we come up to release of v1, I'll be doing a series of posts on the development of Schema Compare for Oracle. For the first post, I thought I would start with the main pitfalls that we stumbled across when developing the product, especially from a SQL Server background. 1. Schemas and Databases The most obvious difference is that the concept of a 'database' is quite different between Oracle and SQL Server. On SQL Server, one server instance has multiple databases, each with separate schemas. There is typically little communication between separate databases, and most databases are no more than about 1000-2000 objects. This means SQL Compare can register an entire database in a reasonable amount of time, and cross-database dependencies probably won't be an issue. It is a quite different scene under Oracle, however. The terms 'database' and 'instance' are used interchangeably, (although technically 'database' refers to the datafiles on disk, and 'instance' the running Oracle process that reads & writes to the database), and a database is a single conceptual entity. This immediately presents problems, as it is infeasible to register an entire database as we do in SQL Compare; in my Oracle install, using the standard recommended options, there are 63975 system objects. If we tried to register all those, not only would it take hours, but the client would probably run out of memory before we finished. As a result, we had to allow people to specify what schemas they wanted to register. This decision had quite a few knock-on effects for the design, which I will cover in a future post. 2. Connecting to Oracle The next obvious difference is in actually connecting to Oracle – in SQL Server, you can specify a server and database, and off you go. On Oracle things are slightly more complicated. SIDs, Service Names, and TNS A database (the files on disk) must have a unique identifier for the databases on the system, called the SID. It also has a global database name, which consists of a name (which doesn't have to match the SID) and a domain. Alternatively, you can identify a database using a service name, which normally has a 1-to-1 relationship with instances, but may not if, for example, using RAC (Real Application Clusters) for redundancy and failover. You specify the computer and instance you want to connect to using TNS (Transparent Network Substrate). The user-visible parts are a config file (tnsnames.ora) on the client machine that specifies how to connect to an instance. For example, the entry for one of my test instances is: SC_11GDB1 = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = simonctest)(PORT = 1521)) ) (CONNECT_DATA = (SID = 11gR1db1) ) ) This gives the hostname, port, and SID of the instance I want to connect to, and associates it with a name (SC_11GDB1). The tnsnames syntax also allows you to specify failover, multiple descriptions and address lists, and client load balancing. You can then specify this TNS identifier as the data source in a connection string. Although using ODP.NET (the .NET dlls provided by Oracle) was fine for internal prototype builds, once we released the EAP we discovered that this simply wasn't an acceptable solution for installs on other people's machines. Due to .NET assembly strong naming, users had to have installed on their machines the exact same version of the ODP.NET dlls as we had on our build server. We couldn't ship the ODP.NET dlls with our installer as the Oracle license agreement prohibited this, and we didn't want to force users to install another Oracle client just so they can run our program. To be able to list the TNS entries in the connection dialog, we also had to locate and parse the tnsnames.ora file, which was complicated by users with several Oracle client installs and intricate TNS entries. After much swearing at our computers, we eventually decided to use a third party Oracle connection library from Devart that we could ship with our program; this could use whatever client version was installed, parse the TNS entries for us, and also had the nice feature of being able to connect to an Oracle server without having any client installed at all. Unfortunately, their current license agreement prevents us from shipping an Oracle SDK, but that's a bridge we'll cross when we get to it. 3. Running synchronization scripts The most important difference is that in Oracle, DDL is non-transactional; you cannot rollback DDL statements like you can on SQL Server. Although we considered various solutions to this, including using the flashback archive or recycle bin, or generating an undo script, no reliable method of completely undoing a half-executed sync script has yet been found; so in this case we simply have to trust that the DBA or developer will check and verify the script before running it. However, before we got to that stage, we had to get the scripts to run in the first place... To run a synchronization script from SQL Compare we essentially pass the script over to the SqlCommand.ExecuteNonQuery method. However, when we tried to do the same for an OracleConnection we got a very strange error – 'ORA-00911: invalid character', even when running the most basic CREATE TABLE command. After much hair-pulling and Googling, we discovered that Oracle has got some very strange behaviour with semicolons at the end of statements. To understand what's going on, we need to take a quick foray into SQL and PL/SQL. PL/SQL is not T-SQL In SQL Server, T-SQL is the language used to interface with the database. It has DDL, DML, control flow, and many other nice features (like Turing-completeness) that you can mix and match in the same script. In Oracle, DDL SQL and PL/SQL are two completely separate languages, with different syntax, different datatypes and different execution engines within the instance. Oracle SQL is much more like 'pure' ANSI SQL, with no state, no control flow, and only the basic DML commands. PL/SQL is the Turing-complete language, but can only do DML and DCL (i.e. BEGIN TRANSATION commands). Any DDL or SQL commands that aren't recognised by the PL/SQL engine have to be passed back to the SQL engine via an EXECUTE IMMEDIATE command. In PL/SQL, a semicolons is a valid token used to delimit the end of a statement. In SQL, a semicolon is not a valid token (even though the Oracle documentation gives them at the end of the syntax diagrams) . When you execute the command CREATE TABLE table1 (COL1 NUMBER); in SQL*Plus the semicolon on the end is a command to SQL*Plus to execute the preceding statement on the server; it strips off the semicolon before passing it on. SQL Developer does a similar thing. When executing a PL/SQL block, however, the syntax is like so: BEGIN INSERT INTO table1 VALUES (1); INSERT INTO table1 VALUES (2); END; / In this case, the semicolon is accepted by the PL/SQL engine as a statement delimiter, and instead the / is the command to SQL*Plus to execute the current block. This explains the ORA-00911 error we got when trying to run the CREATE TABLE command – the server is complaining about the semicolon on the end. This also means that there is no SQL syntax to execute more than one DDL command in the same OracleCommand. Therefore, we would have to do a round-trip to the server for every command we want to execute. Obviously, this would cause lots of network traffic and be very slow on slow or congested networks. Our first attempt at a solution was to wrap every SQL statement (without semicolon) inside an EXECUTE IMMEDIATE command in a PL/SQL block and pass that to the server to execute. One downside of this solution is that we get no feedback as to how the script execution is going; we're currently evaluating better solutions to this thorny issue. Next up: Dependencies; how we solved the problem of being unable to register the entire database, and the knock-on effects to the whole product.

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  • Corsair Hackers Reboot

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

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  • MapRedux - PowerShell and Big Data

    - by Dittenhafer Solutions
    MapRedux – #PowerShell and #Big Data Have you been hearing about “big data”, “map reduce” and other large scale computing terms over the past couple of years and been curious to dig into more detail? Have you read some of the Apache Hadoop online documentation and unfortunately concluded that it wasn't feasible to setup a “test” hadoop environment on your machine? More recently, I have read about some of Microsoft’s work to enable Hadoop on the Azure cloud. Being a "Microsoft"-leaning technologist, I am more inclinded to be successful with experimentation when on the Windows platform. Of course, it is not that I am "religious" about one set of technologies other another, but rather more experienced. Anyway, within the past couple of weeks I have been thinking about PowerShell a bit more as the 2012 PowerShell Scripting Games approach and it occured to me that PowerShell's support for Windows Remote Management (WinRM), and some other inherent features of PowerShell might lend themselves particularly well to a simple implementation of the MapReduce framework. I fired up my PowerShell ISE and started writing just to see where it would take me. Quite simply, the ScriptBlock feature combined with the ability of Invoke-Command to create remote jobs on networked servers provides much of the plumbing of a distributed computing environment. There are some limiting factors of course. Microsoft provided some default settings which prevent PowerShell from taking over a network without administrative approval first. But even with just one adjustment, a given Windows-based machine can become a node in a MapReduce-style distributed computing environment. Ok, so enough introduction. Let's talk about the code. First, any machine that will participate as a remote "node" will need WinRM enabled for remote access, as shown below. This is not exactly practical for hundreds of intended nodes, but for one (or five) machines in a test environment it does just fine. C:> winrm quickconfig WinRM is not set up to receive requests on this machine. The following changes must be made: Set the WinRM service type to auto start. Start the WinRM service. Make these changes [y/n]? y Alternatively, you could take the approach described in the Remotely enable PSRemoting post from the TechNet forum and use PowerShell to create remote scheduled tasks that will call Enable-PSRemoting on each intended node. Invoke-MapRedux Moving on, now that you have one or more remote "nodes" enabled, you can consider the actual Map and Reduce algorithms. Consider the following snippet: $MyMrResults = Invoke-MapRedux -MapReduceItem $Mr -ComputerName $MyNodes -DataSet $dataset -Verbose Invoke-MapRedux takes an instance of a MapReduceItem which references the Map and Reduce scriptblocks, an array of computer names which are the remote nodes, and the initial data set to be processed. As simple as that, you can start working with concepts of big data and the MapReduce paradigm. Now, how did we get there? I have published the initial version of my PsMapRedux PowerShell Module on GitHub. The PsMapRedux module provides the Invoke-MapRedux function described above. Feel free to browse the underlying code and even contribute to the project! In a later post, I plan to show some of the inner workings of the module, but for now let's move on to how the Map and Reduce functions are defined. Map Both the Map and Reduce functions need to follow a prescribed prototype. The prototype for a Map function in the MapRedux module is as follows. A simple scriptblock that takes one PsObject parameter and returns a hashtable. It is important to note that the PsObject $dataset parameter is a MapRedux custom object that has a "Data" property which offers an array of data to be processed by the Map function. $aMap = { Param ( [PsObject] $dataset ) # Indicate the job is running on the remote node. Write-Host ($env:computername + "::Map"); # The hashtable to return $list = @{}; # ... Perform the mapping work and prepare the $list hashtable result with your custom PSObject... # ... The $dataset has a single 'Data' property which contains an array of data rows # which is a subset of the originally submitted data set. # Return the hashtable (Key, PSObject) Write-Output $list; } Reduce Likewise, with the Reduce function a simple prototype must be followed which takes a $key and a result $dataset from the MapRedux's partitioning function (which joins the Map results by key). Again, the $dataset is a MapRedux custom object that has a "Data" property as described in the Map section. $aReduce = { Param ( [object] $key, [PSObject] $dataset ) Write-Host ($env:computername + "::Reduce - Count: " + $dataset.Data.Count) # The hashtable to return $redux = @{}; # Return Write-Output $redux; } All Together Now When everything is put together in a short example script, you implement your Map and Reduce functions, query for some starting data, build the MapReduxItem via New-MapReduxItem and call Invoke-MapRedux to get the process started: # Import the MapRedux and SQL Server providers Import-Module "MapRedux" Import-Module “sqlps” -DisableNameChecking # Query the database for a dataset Set-Location SQLSERVER:\sql\dbserver1\default\databases\myDb $query = "SELECT MyKey, Date, Value1 FROM BigData ORDER BY MyKey"; Write-Host "Query: $query" $dataset = Invoke-SqlCmd -query $query # Build the Map function $MyMap = { Param ( [PsObject] $dataset ) Write-Host ($env:computername + "::Map"); $list = @{}; foreach($row in $dataset.Data) { # Write-Host ("Key: " + $row.MyKey.ToString()); if($list.ContainsKey($row.MyKey) -eq $true) { $s = $list.Item($row.MyKey); $s.Sum += $row.Value1; $s.Count++; } else { $s = New-Object PSObject; $s | Add-Member -Type NoteProperty -Name MyKey -Value $row.MyKey; $s | Add-Member -type NoteProperty -Name Sum -Value $row.Value1; $list.Add($row.MyKey, $s); } } Write-Output $list; } $MyReduce = { Param ( [object] $key, [PSObject] $dataset ) Write-Host ($env:computername + "::Reduce - Count: " + $dataset.Data.Count) $redux = @{}; $count = 0; foreach($s in $dataset.Data) { $sum += $s.Sum; $count += 1; } # Reduce $redux.Add($s.MyKey, $sum / $count); # Return Write-Output $redux; } # Create the item data $Mr = New-MapReduxItem "My Test MapReduce Job" $MyMap $MyReduce # Array of processing nodes... $MyNodes = ("node1", "node2", "node3", "node4", "localhost") # Run the Map Reduce routine... $MyMrResults = Invoke-MapRedux -MapReduceItem $Mr -ComputerName $MyNodes -DataSet $dataset -Verbose # Show the results Set-Location C:\ $MyMrResults | Out-GridView Conclusion I hope you have seen through this article that PowerShell has a significant infrastructure available for distributed computing. While it does take some code to expose a MapReduce-style framework, much of the work is already done and PowerShell could prove to be the the easiest platform to develop and run big data jobs in your corporate data center, potentially in the Azure cloud, or certainly as an academic excerise at home or school. Follow me on Twitter to stay up to date on the continuing progress of my Powershell MapRedux module, and thanks for reading! Daniel

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  • SQL Server Developer Tools &ndash; Codename Juneau vs. Red-Gate SQL Source Control

    - by Ajarn Mark Caldwell
    So how do the new SQL Server Developer Tools (previously code-named Juneau) stack up against SQL Source Control?  Read on to find out. At the PASS Community Summit a couple of weeks ago, it was announced that the previously code-named Juneau software would be released under the name of SQL Server Developer Tools with the release of SQL Server 2012.  This replacement for Database Projects in Visual Studio (also known in a former life as Data Dude) has some great new features.  I won’t attempt to describe them all here, but I will applaud Microsoft for making major improvements.  One of my favorite changes is the way database elements are broken down.  Previously every little thing was in its own file.  For example, indexes were each in their own file.  I always hated that.  Now, SSDT uses a pattern similar to Red-Gate’s and puts the indexes and keys into the same file as the overall table definition. Of course there are really cool features to keep your database model in sync with the actual source scripts, and the rename refactoring feature is now touted as being more than just a search and replace, but rather a “semantic-aware” search and replace.  Funny, it reminds me of SQL Prompt’s Smart Rename feature.  But I’m not writing this just to criticize Microsoft and argue that they are late to the party with this feature set.  Instead, I do see it as a viable alternative for folks who want all of their source code to be version controlled, but there are a couple of key trade-offs that you need to know about when you choose which tool set to use. First, the basics Both tool sets integrate with a wide variety of source control systems including the most popular: Subversion, GIT, Vault, and Team Foundation Server.  Both tools have integrated functionality to produce objects to upgrade your target database when you are ready (DACPACs in SSDT, integration with SQL Compare for SQL Source Control).  If you regularly live in Visual Studio or the Business Intelligence Development Studio (BIDS) then SSDT will likely be comfortable for you.  Like BIDS, SSDT is a Visual Studio Project Type that comes with SQL Server, and if you don’t already have Visual Studio installed, it will install the shell for you.  If you already have Visual Studio 2010 installed, then it will just add this as an available project type.  On the other hand, if you regularly live in SQL Server Management Studio (SSMS) then you will really enjoy the SQL Source Control integration from within SSMS.  Both tool sets store their database model in script files.  In SSDT, these are on your file system like other source files; in SQL Source Control, these are stored in the folder structure in your source control system, and you can always GET them to your file system if you want to browse them directly. For me, the key differentiating factors are 1) a single, unified check-in, and 2) migration scripts.  How you value those two features will likely make your decision for you. Unified Check-In If you do a continuous-integration (CI) style of development that triggers an automated build with unit testing on every check-in of source code, and you use Visual Studio for the rest of your development, then you will want to really consider SSDT.  Because it is just another project in Visual Studio, it can be added to your existing Solution, and you can then do a complete, or unified single check-in of all changes whether they are application or database changes.  This is simply not possible with SQL Source Control because it is in a different development tool (SSMS instead of Visual Studio) and there is no way to do one unified check-in between the two.  You CAN do really fast back-to-back check-ins, but there is the possibility that the automated build that is triggered from the first check-in will cause your unit tests to fail and the CI tool to report that you broke the build.  Of course, the automated build that is triggered from the second check-in which contains the “other half” of your changes should pass and so the amount of time that the build was broken may be very, very short, but if that is very, very important to you, then SQL Source Control just won’t work; you’ll have to use SSDT. Refactoring and Migrations If you work on a mature system, or on a not-so-mature but also not-so-well-designed system, where you want to refactor the database schema as you go along, but you can’t have data suddenly disappearing from your target system, then you’ll probably want to go with SQL Source Control.  As I wrote previously, there are a number of changes which you can make to your database that the comparison tools (both from Microsoft and Red Gate) simply cannot handle without the possibility (or probability) of data loss.  Currently, SSDT only offers you the ability to inject PRE and POST custom deployment scripts.  There is no way to insert your own script in the middle to override the default behavior of the tool.  In version 3.0 of SQL Source Control (Early Access version now available) you have that ability to create your own custom migration script to take the place of the commands that the tool would have done, and ensure the preservation of your data.  Or, even if the default tool behavior would have worked, but you simply know a better way then you can take control and do things your way instead of theirs. You Decide In the environment I work in, our automated builds are not triggered off of check-ins, but off of the clock (currently once per night) and so there is no point at which the automated build and unit tests will be triggered without having both sides of the development effort already checked-in.  Therefore having a unified check-in, while handy, is not critical for us.  As for migration scripts, these are critically important to us.  We do a lot of new development on systems that have already been in production for years, and it is not uncommon for us to need to do a refactoring of the database.  Because of the maturity of the existing system, that often involves data migrations or other additional SQL tasks that the comparison tools just can’t detect on their own.  Therefore, the ability to create a custom migration script to override the tool’s default behavior is very important to us.  And so, you can see why we will continue to use Red Gate SQL Source Control for the foreseeable future.

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  • Unable to connect to Wireless after installing Ubuntu 12.10

    - by Moulik
    I am using Asus U56E laptop and after installing Ubuntu 12.10 alongside Windows 8, I am unable to connect to the Wireless. I have been trying to solve this problem since two weeks and couldn't solve it. Please help. Any answer would be appreciated. Here are some command-line results. lspci -v | grep -iA 7 network ubuntu@ubuntu:~$ lspci -v | grep -iA 7 network 02:00.0 Network controller: Intel Corporation Centrino Wireless-N + WiMAX 6150 (rev 67) Subsystem: Intel Corporation Centrino Wireless-N + WiMAX 6150 BGN Flags: bus master, fast devsel, latency 0, IRQ 52 Memory at de800000 (64-bit, non-prefetchable) [size=8K] Capabilities: <access denied> Kernel driver in use: iwlwifi Kernel modules: iwlwifi lsmod | grep iwlwifi ubuntu@ubuntu:~$ lsmod | grep iwlwifi iwlwifi 386826 0 mac80211 539908 1 iwlwifi cfg80211 206566 2 iwlwifi,mac80211 ubuntu@ubuntu:~$ dmesg | grep iwlwifi [ 57.846261] iwlwifi: Intel(R) Wireless WiFi Link AGN driver for Linux, in-tree: [ 57.846264] iwlwifi: Copyright(c) 2003-2012 Intel Corporation [ 57.846336] iwlwifi 0000:02:00.0: >pci_resource_len = 0x00002000 [ 57.846338] iwlwifi 0000:02:00.0: >pci_resource_base = ffffc90000c7c000 [ 57.846341] iwlwifi 0000:02:00.0: >HW Revision ID = 0x67 [ 57.846438] iwlwifi 0000:02:00.0: >irq 52 for MSI/MSI-X [ 59.558335] iwlwifi 0000:02:00.0: >loaded firmware version 41.28.5.1 build 33926 [ 59.558514] iwlwifi 0000:02:00.0: >CONFIG_IWLWIFI_DEBUG disabled [ 59.558516] iwlwifi 0000:02:00.0: >CONFIG_IWLWIFI_DEBUGFS enabled [ 59.558517] iwlwifi 0000:02:00.0: >CONFIG_IWLWIFI_DEVICE_TRACING enabled [ 59.558519] iwlwifi 0000:02:00.0: >CONFIG_IWLWIFI_DEVICE_TESTMODE enabled [ 59.558520] iwlwifi 0000:02:00.0: >CONFIG_IWLWIFI_P2P disabled [ 59.558522] iwlwifi 0000:02:00.0: >Detected Intel(R) Centrino(R) Wireless-N + WiMAX 6150 BGN, REV=0x84 [ 59.558583] iwlwifi 0000:02:00.0: >L1 Disabled; Enabling L0S [ 59.569083] iwlwifi 0000:02:00.0: >device EEPROM VER=0x557, CALIB=0x6 [ 59.569085] iwlwifi 0000:02:00.0: >Device SKU: 0x150 [ 59.569087] iwlwifi 0000:02:00.0: >Valid Tx ant: 0x1, Valid Rx ant: 0x3 [ 59.569100] iwlwifi 0000:02:00.0: >Tunable channels: 13 802.11bg, 0 802.11a channels [ 70.208469] iwlwifi 0000:02:00.0: >L1 Disabled; Enabling L0S [ 70.208648] iwlwifi 0000:02:00.0: >Radio type=0x1-0x2-0x0 [ 70.366319] iwlwifi 0000:02:00.0: >L1 Disabled; Enabling L0S [ 70.366470] iwlwifi 0000:02:00.0: >Radio type=0x1-0x2-0x0 sudo lshw -c network ubuntu@ubuntu:~$ sudo lshw -c network *-network description: Wireless interface product: Centrino Wireless-N + WiMAX 6150 vendor: Intel Corporation physical id: 0 bus info: pci@0000:02:00.0 logical name: wlan0 version: 67 serial: 40:25:c2:84:99:c4 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=iwlwifi driverversion=3.5.0-17-generic firmware=41.28.5.1 build 33926 latency=0 link=no multicast=yes wireless=IEEE 802.11bgn resources: irq:52 memory:de800000-de801fff *-network description: Ethernet interface product: AR8151 v2.0 Gigabit Ethernet vendor: Atheros Communications Inc. physical id: 0 bus info: pci@0000:04:00.0 logical name: eth0 version: c0 serial: 54:04:a6:2b:6a:ef capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress vpd bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=atl1c driverversion=1.0.1.0-NAPI latency=0 link=no multicast=yes port=twisted pair resources: irq:54 memory:dd400000-dd43ffff ioport:a000(size=128) ifconfig ubuntu@ubuntu:~$ ifconfig eth0 Link encap:Ethernet HWaddr 54:04:a6:2b:6a:ef UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:176 errors:0 dropped:0 overruns:0 frame:0 TX packets:176 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:14368 (14.3 KB) TX bytes:14368 (14.3 KB) wlan0 Link encap:Ethernet HWaddr 40:25:c2:84:99:c4 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) iwconfig ubuntu@ubuntu:~$ iwconfig eth0 no wireless extensions. lo no wireless extensions. wlan0 IEEE 802.11bgn ESSID:off/any Mode:Managed Access Point: Not-Associated Tx-Power=15 dBm Retry long limit:7 RTS thr:off Fragment thr:off Power Management:off iwlist scan ubuntu@ubuntu:~$ iwlist scan eth0 Interface doesn't support scanning. lo Interface doesn't support scanning. wlan0 No scan results nm-tool ubuntu@ubuntu:~$ nm-tool NetworkManager Tool State: disconnected - Device: eth0 ----------------------------------------------------------------- Type: Wired Driver: atl1c State: unavailable Default: no HW Address: 54:04:A6:2B:6A:EF Capabilities: Carrier Detect: yes Wired Properties Carrier: off - Device: wlan0 ---------------------------------------------------------------- Type: 802.11 WiFi Driver: iwlwifi State: disconnected Default: no HW Address: 40:25:C2:84:99:C4 Capabilities: Wireless Properties WEP Encryption: yes WPA Encryption: yes WPA2 Encryption: yes Wireless Access Points hypeness2: Infra, 00:21:29:DA:08:4F, Freq 2462 MHz, Rate 54 Mb/s, Strength 42 WPA love: Infra, 68:7F:74:17:02:66, Freq 2412 MHz, Rate 54 Mb/s, Strength 19 WPA WPA2 DIRECT-MwSCX-3400Pamela: Infra, 02:15:99:A3:3F:AC, Freq 2412 MHz, Rate 54 Mb/s, Strength 22 WPA2 router: Infra, 1C:AF:F7:D6:76:F3, Freq 2417 MHz, Rate 54 Mb/s, Strength 20 WPA2 wing: Infra, E8:40:F2:34:E4:F7, Freq 2437 MHz, Rate 54 Mb/s, Strength 20 WPA WPA2 132LINKSYS: Infra, 00:1A:70:80:1F:E9, Freq 2437 MHz, Rate 54 Mb/s, Strength 57 WEP VMITTAL: Infra, E0:46:9A:3C:F0:C4, Freq 2412 MHz, Rate 54 Mb/s, Strength 27 WEP HP-Print-10-LaserJet 1025: Infra, 7C:E9:D3:7E:F8:10, Freq 2437 MHz, Rate 54 Mb/s, Strength 59 ACNBB: Infra, 00:26:75:22:A6:2F, Freq 2437 MHz, Rate 54 Mb/s, Strength 20 SATKAIVAL: Infra, 00:18:E7:CE:69:A6, Freq 2412 MHz, Rate 54 Mb/s, Strength 69 WPA WPA2 hypeness: Infra, B8:E6:25:24:C3:B1, Freq 2437 MHz, Rate 54 Mb/s, Strength 54 WPA WPA2 CSNetwork: Infra, BC:14:01:58:C5:88, Freq 2437 MHz, Rate 54 Mb/s, Strength 25 WPA WPA2 tharma: Infra, BC:14:01:E2:06:18, Freq 2412 MHz, Rate 54 Mb/s, Strength 15 WPA WPA2 Active2.4: Infra, 10:6F:3F:0E:F3:8E, Freq 2462 MHz, Rate 54 Mb/s, Strength 17 WPA WPA2 ACNBB: Infra, 00:26:75:58:4E:7A, Freq 2437 MHz, Rate 54 Mb/s, Strength 85 KO: Infra, BC:14:01:2E:AF:A8, Freq 2452 MHz, Rate 54 Mb/s, Strength 22 WPA WPA2 FEAR: Infra, 00:18:4D:C0:BC:58, Freq 2462 MHz, Rate 54 Mb/s, Strength 17 WPA Pamela: Infra, BC:14:01:52:F6:F8, Freq 2412 MHz, Rate 54 Mb/s, Strength 24 WPA WPA2 bvrk2: Infra, 78:CD:8E:7B:3C:79, Freq 2457 MHz, Rate 54 Mb/s, Strength 19 WPA WPA2 BELL030: Infra, D8:6C:E9:17:AF:09, Freq 2462 MHz, Rate 54 Mb/s, Strength 22 WPA2 Desai: Infra, 00:1D:7E:52:FB:C5, Freq 2437 MHz, Rate 54 Mb/s, Strength 14 WEP Sritharan: Infra, BC:14:01:E5:59:78, Freq 2462 MHz, Rate 54 Mb/s, Strength 19 WPA WPA2 PFN: Infra, 00:13:10:8B:CF:45, Freq 2437 MHz, Rate 54 Mb/s, Strength 19 WEP rfkill list all ubuntu@ubuntu:~$ rfkill list all 0: asus-wlan: Wireless LAN Soft blocked: no Hard blocked: no 1: asus-wimax: WiMAX Soft blocked: yes Hard blocked: no 2: phy0: Wireless LAN Soft blocked: no Hard blocked: no so these are some more results sudo modprobe -r iwlwifi ubuntu@ubuntu:~$ sudo modprobe -r iwlwifi sudo modprobe iwlwifi 11n_disable=1 ubuntu@ubuntu:~$ sudo modprobe iwlwifi 11n_disable=1 echo "blacklist asus_wmi" | sudo tee -a /etcmodprobe.d/blacklist.conf ubuntu@ubuntu:~$ echo "blacklist asus_wmi" | sudo tee -a /etc/modprobe.d/blacklist.conf blacklist asus_wmi echo "options iwlwifi 11n_disable=1" | sudo tee /etc/modprobe.d/iwlwifi.conf ubuntu@ubuntu:~$ echo "options iwlwifi 11n_disable=1" | sudo tee /etc/modprobe.d/iwlwifi.conf options iwlwifi 11n_disable=1 sudo modprobe -rfv iwlwifi ubuntu@ubuntu:~$ sudo modprobe -rfv iwlwifi rmmod /lib/modules/3.5.0-17-generic/kernel/drivers/net/wireless/iwlwifi/iwlwifi.ko rmmod /lib/modules/3.5.0-17-generic/kernel/net/mac80211/mac80211.ko rmmod /lib/modules/3.5.0-17-generic/kernel/net/wireless/cfg80211.ko sudo modprobe -v iwlwifi ubuntu@ubuntu:~$ sudo modprobe -v iwlwifi insmod /lib/modules/3.5.0-17-generic/kernel/net/wireless/cfg80211.ko insmod /lib/modules/3.5.0-17-generic/kernel/net/mac80211/mac80211.ko insmod /lib/modules/3.5.0-17-generic/kernel/drivers/net/wireless/iwlwifi/iwlwifi.ko 11n_disable=1

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  • Advice for a distracted, unhappy, recently graduated programmer? [closed]

    - by Re-Invent
    I graduated 4 months ago. I had offers from a few good places to work at. At the same time I wanted to stick to building a small software business of my own, still have some ideas with good potential, some half done projects frozen in my github. But due to social pressures, I chose a job, the pay is great, but I am half-passionate about it. A small team of smart folks building useful product, working out contracts across the world. I've started finding it extremely boring. Boring to the extent that I skip 2-3 days a week together not doing work. Neither do I spend that time progressing any of my own projects. Yes, I feel stupid at the way I'm wasting time, but I don't understand exactly why is it happening. It's as if all the excitement has been drained. What can I do about it? Long version: School - I was in third standard. Only students, 6th grade had access to computer labs. I once peeked into the lab from the little door opening. No hard-disks, MS DOS on 5 1/2 inch floppies. I asked a senior student to play some sound in BASIC. He used PLAY to compose a tune. Boy! I was so excited, I was jumping from within. Back home, asked my brother to teach me some programming. We bought a book "MODERN All About GW-BASIC for Schools & Colleges". The book had everything, right from printing, to taking input, file i/o, game programming, machine level support, etc. I was in 6th standard, wrote my first game - a wheel of fortune, rotated the wheel by manipulating 16 color palette's definition. Got internet soon, got hooked to QuickBasic programming community. Made some more games "007 in Danger", "Car Crush 2" for submission to allbasiccode archives. I was extremely excited about all this. My interests now swayed into "hacking" (computer security). Taught myself some perl, found it annoying, learnt PHP and a bit of SQL. Also taught myself Visual Basic one of the winters and wrote a pacman clone with Direct X. By the time I was in 10th standard, I created some evil tools using visual basic, php and mysql and eventually landed myself into an unpaid side-job at a government facility, building evil tools for them. It was a dream come true for crackers of that time. And so was I, still very excited. Things changed soon, last two years of school were not so great as I was balancing preps for college, work at govt. and studies for school at same time. College - College was opposite of all I had wished it to be. I imagined it to be a place where I'd spend my 4 years building something awesome. It was rather an epitome of rote learning, attendance, rules, busy schedules, ban on personal laptops, hardly any hackers surrounding you and shit like that. We had to take permissions to even introduce some cultural/creative activities in our annual schedule. The labs won't be open on weekends because the lab employees had to have their leaves. Yes, a horrible place for someone like me. I still managed to pull out a project with a friend over 2 months. Showed it to people high in the academia hierarchy. They were immensely impressed, we proposed to allow personal computers for students. They made up half-assed reasons and didn't agree. We felt frustrated. And so on, I still managed to teach myself new languages, do new projects of my own, do an intern at the same govt. facility, start a small business for sometime, give a talk at a conference I'm passionate about, win game-dev and hacking contest at most respected colleges, solve good deal of programming contest problems, etc. At the same time I was not content with all these restrictions, great emphasis on rote learning, and sheer wastage of time due to college. I never felt I was overdoing, but now I feel I burnt myself out. During my last days at college, I did an intern at a bigco. While I spent my time building prototypes for certain LBS, the other interns around me, even a good friend, was just skipping time. I thought maybe, in a few weeks he would put in some serious efforts at work assigned to him, but all he did was to find creative ways to skip work, hide his face from manager, engage people in talks if they try to question his progress, etc. I tried a few time to get him on track, but it seems all he wanted was to "not to work hard at all and still reap the fruits". I don't know how others take such people, but I find their vicinity very very poisonous to one's own motivation and productivity. Over that, the place where I come from, HRs don't give much value to what have you done past 4 years. So towards the end of out intern, we all were offered work at the bigco, but the slacker, even after not writing more than 200 lines of code was made a much better offer. I felt enraged instantly - "Is this how the corp world treats someone who does fruitful, if not extra-ordinary work form them for past 6 months?". Yes, I did try to negotiate and debate. The bigcos seem blind due to departmentalization of responsibilities and many layers of management. I decided not to be in touch with any characters of that depressing play. Probably the busy time I had at college, ignoring friends, ignoring fun and squeezing every bit of free time for myself is also responsible. Probably this is what has drained all my willingness to work for anyone. I find my day job boring, at the same time I with to maintain it for financial reasons. I feel a bit burnt out, unsatisfied and at the same time an urge to quit working for someone else and start finishing my frozen side-projects (which may be profitable). Though I haven't got much to support myself with food, office, internet bills, etc in savings. I still have my day job, but I don't find it very interesting, even though the pay is higher than the slacker, I don't find money to be a great motivator here. I keep comparing myself to my past version. I wonder how to get rid of this and reboot myself back to the way I was in school days - excited about it, tinkering, building, learning new things daily, and NOT BORED?

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  • BI Applications overview

    - by sv744
    Welcome to Oracle BI applications blog! This blog will talk about various features, general roadmap, description of functionality and implementation steps related to Oracle BI applications. In the first post we start with an overview of the BI apps and will delve deeper into some of the topics below in the upcoming weeks and months. If there are other topics you would like us to talk about, pl feel free to provide feedback on that. The Oracle BI applications are a set of pre-built applications that enable pervasive BI by providing role-based insight for each functional area, including sales, service, marketing, contact center, finance, supplier/supply chain, HR/workforce, and executive management. For example, Sales Analytics includes role-based applications for sales executives, sales management, as well as front-line sales reps, each of whom have different needs. The applications integrate and transform data from a range of enterprise sources—including Siebel, Oracle, PeopleSoft, SAP, and others—into actionable intelligence for each business function and user role. This blog  starts with the key benefits and characteristics of Oracle BI applications. In a series of subsequent blogs, each of these points will be explained in detail. Why BI apps? Demonstrate the value of BI to a business user, show reports / dashboards / model that can answer their business questions as part of the sales cycle. Demonstrate technical feasibility of BI project and significantly lower risk and improve success Build Vs Buy benefit Don’t have to start with a blank sheet of paper. Help consolidate disparate systems Data integration in M&A situations Insulate BI consumers from changes in the OLTP Present OLTP data and highlight issues of poor data / missing data – and improve data quality and accuracy Prebuilt Integrations BI apps support prebuilt integrations against leading ERP sources: Fusion Applications, E- Business Suite, Peoplesoft, JD Edwards, Siebel, SAP Co-developed with inputs from functional experts in BI and Applications teams. Out of the box dimensional model to source model mappings Multi source and Multi Instance support Rich Data Model    BI apps have a very rich dimensionsal data model built over 10 years that incorporates best practises from BI modeling perspective as well as reflect the source system complexities  Thanks for reading a long post, and be on the lookout for future posts.  We will look forward to your valuable feedback on these topics as well as suggestions on what other topics would you like us to cover. I Conformed dimensional model across all business subject areas allows cross functional reporting, e.g. customer / supplier 360 Over 360 fact tables across 7 product areas CRM – 145, SCM – 47, Financials – 28, Procurement – 20, HCM – 27, Projects – 18, Campus Solutions – 21, PLM - 56 Supported by 300 physical dimensions Support for extensive calendars; Gregorian, enterprise and ledger based Conformed data model and metrics for real time vs warehouse based reporting  Multi-tenant enabled Extensive BI related transformations BI apps ETL and data integration support various transformations required for dimensional models and reporting requirements. All these have been distilled into common patterns and abstracted logic which can be readily reused across different modules Slowly Changing Dimension support Hierarchy flattening support Row / Column Hybrid Hierarchy Flattening As Is vs. As Was hierarchy support Currency Conversion :-  Support for 3 corporate, CRM, ledger and transaction currencies UOM conversion Internationalization / Localization Dynamic Data translations Code standardization (Domains) Historical Snapshots Cycle and process lifecycle computations Balance Facts Equalization of GL accounting chartfields/segments Standardized values for categorizing GL accounts Reconciliation between GL and subledgers to track accounted/transferred/posted transactions to GL Materialization of data only available through costly and complex APIs e.g. Fusion Payroll, EBS / Fusion Accruals Complex event Interpretation of source data – E.g. o    What constitutes a transfer o    Deriving supervisors via position hierarchy o    Deriving primary assignment in PSFT o    Categorizing and transposition to measures of Payroll Balances to specific metrics to support side by side comparison of measures of for example Fixed Salary, Variable Salary, Tax, Bonus, Overtime Payments. o    Counting of Events – E.g. converting events to fact counters so that for example the number of hires can easily be added up and compared alongside the total transfers and terminations. Multi pass processing of multiple sources e.g. headcount, salary, promotion, performance to allow side to side comparison. Adding value to data to aid analysis through banding, additional domain classifications and groupings to allow higher level analytical reporting and data discovery Calculation of complex measures examples: o    COGs, DSO, DPO, Inventory turns  etc o    Transfers within a Hierarchy or out of / into a hierarchy relative to view point in hierarchy. Configurability and Extensibility support  BI apps offer support for extensibility for various entities as automated extensibility or part of extension methodology Key Flex fields and Descriptive Flex support  Extensible attribute support (JDE)  Conformed Domains ETL Architecture BI apps offer a modular adapter architecture which allows support of multiple product lines into a single conformed model Multi Source Multi Technology Orchestration – creates load plan taking into account task dependencies and customers deployment to generate a plan based on a customers of multiple complex etl tasks Plan optimization allowing parallel ETL tasks Oracle: Bit map indexes and partition management High availability support    Follow the sun support. TCO BI apps support several utilities / capabilities that help with overall total cost of ownership and ensure a rapid implementation Improved cost of ownership – lower cost to deploy On-going support for new versions of the source application Task based setups flows Data Lineage Functional setup performed in Web UI by Functional person Configuration Test to Production support Security BI apps support both data and object security enabling implementations to quickly configure the application as per the reporting security needs Fine grain object security at report / dashboard and presentation catalog level Data Security integration with source systems  Extensible to support external data security rules Extensive Set of KPIs Over 7000 base and derived metrics across all modules Time series calculations (YoY, % growth etc) Common Currency and UOM reporting Cross subject area KPIs (analyzing HR vs GL data, drill from GL to AP/AR, etc) Prebuilt reports and dashboards 3000+ prebuilt reports supporting a large number of industries Hundreds of role based dashboards Dynamic currency conversion at dashboard level Highly tuned Performance The BI apps have been tuned over the years for both a very performant ETL and dashboard performance. The applications use best practises and advanced database features to enable the best possible performance. Optimized data model for BI and analytic queries Prebuilt aggregates& the ability for customers to create their own aggregates easily on warehouse facts allows for scalable end user performance Incremental extracts and loads Incremental Aggregate build Automatic table index and statistics management Parallel ETL loads Source system deletes handling Low latency extract with Golden Gate Micro ETL support Bitmap Indexes Partitioning support Modularized deployment, start small and add other subject areas seamlessly Source Specfic Staging and Real Time Schema Support for source specific operational reporting schema for EBS, PSFT, Siebel and JDE Application Integrations The BI apps also allow for integration with source systems as well as other applications that provide value add through BI and enable BI consumption during operational decision making Embedded dashboards for Fusion, EBS and Siebel applications Action Link support Marketing Segmentation Sales Predictor Dashboard Territory Management External Integrations The BI apps data integration choices include support for loading extenral data External data enrichment choices : UNSPSC, Item class etc. Extensible Spend Classification Broad Deployment Choices Exalytics support Databases :  Oracle, Exadata, Teradata, DB2, MSSQL ETL tool of choice : ODI (coming), Informatica Extensible and Customizable Extensible architecture and Methodology to add custom and external content Upgradable across releases

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  • HTG Explains: Should You Buy Extended Warranties?

    - by Chris Hoffman
    Buy something at an electronics store and you’ll be confronted by a pushy salesperson who insists you need an extended warranty. You’ll also see extended warranties pushed hard when shopping online. But are they worth it? There’s a reason stores push extended warranties so hard. They’re almost always pure profit for the store involved. An electronics store may live on razor-thin product margins and make big profits on extended warranties and overpriced HDMI cables. You’re Already Getting Multiple Warranties First, back up. The product you’re buying already includes a warranty. In fact, you’re probably getting several different types of warranties. Store Return and Exchange: Most electronics stores allow you to return a malfunctioning product within the first 15 or 30 days and they’ll provide you with a new one. The exact period of time will vary from store to store. If you walk out of the store with a defective product and have to swap it for a new one within the first few weeks, this should be easy. Manufacturer Warranty: A device’s manufacturer — whether the device is a laptop, a television, or a graphics card — offers their own warranty period. The manufacturer warranty covers you after the store refuses to take the product back and exchange it. The length of this warranty depends on the type of product. For example, a cheap laptop may only offer a one-year manufacturer warranty, while a more expensive laptop may offer a two-year warranty. Credit Card Warranty Extension: Many credit cards offer free extended warranties on products you buy with that credit card. Credit card companies will often give you an additional year of warranty. For example, if you buy a laptop with a two year warranty and it fails in the third year, you could then contact your credit card company and they’d cover the cost of fixing or replacing it. Check your credit card’s benefits and fine print for more information. Why Extended Warranties Are Bad You’re already getting a fairly long warranty period, especially if you have a credit card that offers you a free extended warranty — these are fairly common. If the product you get is a “lemon” and has a manufacturing error, it will likely fail pretty soon — well within your warranty period. The extended warranty matters after all your other warranties are exhausted. In the case of a laptop with a two-year warranty that you purchase with a credit card giving you a one-year warranty extension, your extended warranty will kick in three years after you purchase the laptop. In that many years, your current laptop will likely feel pretty old and laptops that are as good — or better — will likely be pretty cheap. If it’s a television, better television displays will be available at a lower price point. You’ll either want to upgrade to a newer model or you’ll be able to buy a new, just-as-good product for very cheap. You’ll only have to pay out-of-pocket if your device fails after the normal warranty period — in over two or three years for typical laptops purchased with a decent credit card. Save the money you would have spent on the warranty and put it towards a future upgrade. How Much Do Extended Warranties Cost? Let’s look at an example from a typical pushy retail outlet, Best Buy. We went to Best Buy’s website and found a pretty standard $600 Samsung laptop. This laptop comes with a one-year warranty period. If purchased with a fairly common credit card, you can easily get a two-year warranty period on this laptop without spending an additional penny. (Yes, such credit cards are available with no yearly fees.) During the check-out process, Best Buy tries to sell you a Geek Squad “Accidental Protection Plan.” To get an additional year of Best Buy’s extended warranty, you’d have to pay $324.98 for a “3-Year Accidental Protection Plan”. You’d basically be paying more than half the price of your laptop for an additional year of warranty — remember, the standard warranties would cover you anyway for the first two years. If this laptop did break sometime between two and three years from now, we wouldn’t be surprised if you could purchase a comparable laptop for about $325 anyway. And, if you don’t need to replace it, you’ve saved that money. Best Buy would object that this isn’t a standard extended warranty. It’s a supercharged warranty plan that will also provide coverage if you spill something on your laptop or drop it and break it. You just have to ask yourself a question. What are the odds that you’ll drop your laptop or spill something on it? They’re probably pretty low if you’re a typical human being. Is it worth spending more than half the price of the laptop just in case you’ll make an uncommon mistake? Probably not. There may be occasional exceptions to this — some Apple users swear by Apple’s AppleCare, for example — but you should generally avoid buying these things. There’s a reason stores are so pushy about extended warranties, and it’s not because they want to help protect you. It’s because they’re making lots of profit from these plans, and they’re making so much profit because they’re not a good deal for customers. Image Credit: Philip Taylor on Flickr     

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  • Java EE 7 Survey Results!

    - by reza_rahman
    On November 8th, the Java EE EG posted a survey to gather broad community feedback on a number of critical open issues. For reference, you can find the original survey here. We kept the survey open for about three weeks until November 30th. To our delight, over 1100 developers took time out of their busy lives to let their voices be heard! The results of the survey were sent to the EG on December 12th. The subsequent EG discussion is available here. The exact summary sent to the EG is available here. We would like to take this opportunity to thank each and every one the individuals who took the survey. It is very appreciated, encouraging and worth it's weight in gold. In particular, I tried to capture just some of the high-quality, intelligent, thoughtful and professional comments in the summary to the EG. I highly encourage you to continue to stay involved, perhaps through the Adopt-a-JSR program. We would also like to sincerely thank java.net, JavaLobby, TSS and InfoQ for helping spread the word about the survey. Below is a brief summary of the results... APIs to Add to Java EE 7 Full/Web Profile The first question asked which of the four new candidate APIs (WebSocket, JSON-P, JBatch and JCache) should be added to the Java EE 7 Full and Web profile respectively. As the following graph shows, there was significant support for adding all the new APIs to the full profile: Support is relatively the weakest for Batch 1.0, but still good. A lot of folks saw WebSocket 1.0 as a critical technology with comments such as this one: "A modern web application needs Web Sockets as first class citizens" While it is clearly seen as being important, a number of commenters expressed dissatisfaction with the lack of a higher-level JSON data binding API as illustrated by this comment: "How come we don't have a Data Binding API for JSON" JCache was also seen as being very important as expressed with comments like: "JCache should really be that foundational technology on which other specs have no fear to depend on" The results for the Web Profile is not surprising. While there is strong support for adding WebSocket 1.0 and JSON-P 1.0 to the Web Profile, support for adding JCache 1.0 and Batch 1.0 is relatively weak. There was actually significant opposition to adding Batch 1. 0 (with 51.8% casting a 'No' vote). Enabling CDI by Default The second question asked was whether CDI should be enabled in Java EE environments by default. A significant majority of 73.3% developers supported enabling CDI, only 13.8% opposed. Comments such as these two reflect a strong general support for CDI as well as a desire for better Java EE alignment with CDI: "CDI makes Java EE quite valuable!" "Would prefer to unify EJB, CDI and JSF lifecycles" There is, however, a palpable concern around the performance impact of enabling CDI by default as exemplified by this comment: "Java EE projects in most cases use CDI, hence it is sensible to enable CDI by default when creating a Java EE application. However, there are several issues if CDI is enabled by default: scanning can be slow - not all libs use CDI (hence, scanning is not needed)" Another significant concern appears to be around backwards compatibility and conflict with other JSR 330 implementations like Spring: "I am leaning towards yes, however can easily imagine situations where errors would be caused by automatically activating CDI, especially in cases of backward compatibility where another DI engine (such as Spring and the like) happens to use the same mechanics to inject dependencies and in that case there would be an overlap in injections and probably an uncertain outcome" Some commenters such as this one attempt to suggest solutions to these potential issues: "If you have Spring in use and use javax.inject.Inject then you might get some unexpected behavior that could be equally confusing. I guess there will be a way to switch CDI off. I'm tempted to say yes but am cautious for this reason" Consistent Usage of @Inject The third question was around using CDI/JSR 330 @Inject consistently vs. allowing JSRs to create their own injection annotations. A slight majority of 53.3% developers supported using @Inject consistently across JSRs. 28.8% said using custom injection annotations is OK, while 18.0% were not sure. The vast majority of commenters were strongly supportive of CDI and general Java EE alignment with CDI as illistrated by these comments: "Dependency Injection should be standard from now on in EE. It should use CDI as that is the DI mechanism in EE and is quite powerful. Having a new JSR specific DI mechanism to deal with just means more reflection, more proxies. JSRs should also be constructed to allow some of their objects Injectable. @Inject @TransactionalCache or @Inject @JMXBean etc...they should define the annotations and stereotypes to make their code less procedural. Dog food it. If there is a shortcoming in CDI for a JSR fix it and we will all be grateful" "We're trying to make this a comprehensive platform, right? Injection should be a fundamental part of the platform; everything else should build on the same common infrastructure. Each-having-their-own is just a recipe for chaos and having to learn the same thing 10 different ways" Expanding the Use of @Stereotype The fourth question was about expanding CDI @Stereotype to cover annotations across Java EE beyond just CDI. A significant majority of 62.3% developers supported expanding the use of @Stereotype, only 13.3% opposed. A majority of commenters supported the idea as well as the theme of general CDI/Java EE alignment as expressed in these examples: "Just like defining new types for (compositions of) existing classes, stereotypes can help make software development easier" "This is especially important if many EJB services are decoupled from the EJB component model and can be applied via individual annotations to Java EE components. @Stateless is a nicely compact annotation. Code will not improve if that will have to be applied in the future as @Transactional, @Pooled, @Secured, @Singlethreaded, @...." Some, however, expressed concerns around increased complexity such as this commenter: "Could be very convenient, but I'm afraid if it wouldn't make some important class annotations less visible" Expanding Interceptor Use The final set of questions was about expanding interceptors further across Java EE... A very solid 96.3% of developers wanted to expand interceptor use to all Java EE components. 35.7% even wanted to expand interceptors to other Java EE managed classes. Most developers (54.9%) were not sure if there is any place that injection is supported that should not support interceptors. 32.8% thought any place that supports injection should also support interceptors. Only 12.2% were certain that there are places where injection should be supported but not interceptors. The comments reflected the diversity of opinions, generally supportive of interceptors: "I think interceptors are as fundamental as injection and should be available anywhere in the platform" "The whole usage of interceptors still needs to take hold in Java programming, but it is a powerful technology that needs some time in the Sun. Basically it should become part of Java SE, maybe the next step after lambas?" A distinct chain of thought separated interceptors from filters and listeners: "I think that the Servlet API already provides a rich set of possibilities to hook yourself into different Servlet container events. I don't find a need to 'pollute' the Servlet model with the Interceptors API"

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  • "power limit notification" clobbering on 12G Dell servers with RHEL6

    - by Andrew B
    Server: Poweredge r620 OS: RHEL 6.4 Kernel: 2.6.32-358.18.1.el6.x86_64 I'm experiencing application alarms in my production environment. Critical CPU hungry processes are being starved of resources and causing a processing backlog. The problem is happening on all the 12th Generation Dell servers (r620s) in a recently deployed cluster. As near as I can tell, instances of this happening are matching up to peak CPU utilization, accompanied by massive amounts of "power limit notification" spam in dmesg. An excerpt of one of these events: Nov 7 10:15:15 someserver [.crit] CPU12: Core power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU0: Core power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU6: Core power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU14: Core power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU18: Core power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU2: Core power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU4: Core power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU16: Core power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU0: Package power limit notification (total events = 11) Nov 7 10:15:15 someserver [.crit] CPU6: Package power limit notification (total events = 13) Nov 7 10:15:15 someserver [.crit] CPU14: Package power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU18: Package power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU20: Core power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU8: Core power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU2: Package power limit notification (total events = 12) Nov 7 10:15:15 someserver [.crit] CPU10: Core power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU22: Core power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU4: Package power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU16: Package power limit notification (total events = 13) Nov 7 10:15:15 someserver [.crit] CPU20: Package power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU8: Package power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU10: Package power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU22: Package power limit notification (total events = 14) Nov 7 10:15:15 someserver [.crit] CPU15: Core power limit notification (total events = 369) Nov 7 10:15:15 someserver [.crit] CPU3: Core power limit notification (total events = 369) Nov 7 10:15:15 someserver [.crit] CPU1: Core power limit notification (total events = 369) Nov 7 10:15:15 someserver [.crit] CPU5: Core power limit notification (total events = 369) Nov 7 10:15:15 someserver [.crit] CPU17: Core power limit notification (total events = 369) Nov 7 10:15:15 someserver [.crit] CPU13: Core power limit notification (total events = 369) Nov 7 10:15:15 someserver [.crit] CPU15: Package power limit notification (total events = 375) Nov 7 10:15:15 someserver [.crit] CPU3: Package power limit notification (total events = 374) Nov 7 10:15:15 someserver [.crit] CPU1: Package power limit notification (total events = 376) Nov 7 10:15:15 someserver [.crit] CPU5: Package power limit notification (total events = 376) Nov 7 10:15:15 someserver [.crit] CPU7: Core power limit notification (total events = 369) Nov 7 10:15:15 someserver [.crit] CPU19: Core power limit notification (total events = 369) Nov 7 10:15:15 someserver [.crit] CPU17: Package power limit notification (total events = 377) Nov 7 10:15:15 someserver [.crit] CPU9: Core power limit notification (total events = 369) Nov 7 10:15:15 someserver [.crit] CPU21: Core power limit notification (total events = 369) Nov 7 10:15:15 someserver [.crit] CPU23: Core power limit notification (total events = 369) Nov 7 10:15:15 someserver [.crit] CPU11: Core power limit notification (total events = 369) Nov 7 10:15:15 someserver [.crit] CPU13: Package power limit notification (total events = 376) Nov 7 10:15:15 someserver [.crit] CPU7: Package power limit notification (total events = 375) Nov 7 10:15:15 someserver [.crit] CPU19: Package power limit notification (total events = 375) Nov 7 10:15:15 someserver [.crit] CPU9: Package power limit notification (total events = 374) Nov 7 10:15:15 someserver [.crit] CPU21: Package power limit notification (total events = 375) Nov 7 10:15:15 someserver [.crit] CPU23: Package power limit notification (total events = 374) A little Google Fu reveals that this is typically associated with the CPU running hot, or voltage regulation kicking in. I don't think that's what is happening though. Temperature sensors for all servers in the cluster are running fine, Power Cap Policy is disabled in the iDRAC, and my System Profile is set to "Performance" on all of these servers: # omreport chassis biossetup | grep -A10 'System Profile' System Profile Settings ------------------------------------------ System Profile : Performance CPU Power Management : Maximum Performance Memory Frequency : Maximum Performance Turbo Boost : Enabled C1E : Disabled C States : Disabled Monitor/Mwait : Enabled Memory Patrol Scrub : Standard Memory Refresh Rate : 1x Memory Operating Voltage : Auto Collaborative CPU Performance Control : Disabled A Dell mailing list post describes the symptoms almost perfectly. Dell suggested that the author try using the Performance profile, but that didn't help. He ended up applying some settings in Dell's guide for configuring a server for low latency environments and one of those settings (or a combination thereof) seems to have fixed the problem. Kernel.org bug #36182 notes that power-limit interrupt debugging was enabled by default, which is causing performance degradation in scenarios where CPU voltage regulation is kicking in. A RHN KB article (RHN login required) mentions a problem impacting PE r620 and r720 servers not running the Performance profile, and recommends an update to a kernel released two weeks ago. ...Except we are running the Performance profile... Everything I can find online is running me in circles here. What's the heck is going on?

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  • Skipping scheduled self-tests and predicting drive EOL

    - by Steve Madsen
    For a few weeks now, smartd has been reporting that it is skipping some of its scheduled self-tests on the weekends: Apr 24 18:29:32 calvin smartd[4758]: Device: /dev/sda, skip scheduled Offline Immediate Test; 40% remaining of current Self-Test. Apr 24 18:29:33 calvin smartd[4758]: Device: /dev/sdb, skip scheduled Offline Immediate Test; 50% remaining of current Self-Test. The drives in this RAID-1 array are set to run an offline test four times a day, a short self-test at 2am every day, and a long self-test on Saturdays at 2am. For some reason, it looks like the long self-test is taking longer, causing the other scheduled tests to be skipped. First question: is this a sign of likely drive failure? Then today, smartd reported that a self-test failed. Here is the output of smartctl -a /dev/sdb: smartctl version 5.38 [i686-pc-linux-gnu] Copyright (C) 2002-8 Bruce Allen Home page is http://smartmontools.sourceforge.net/ === START OF INFORMATION SECTION === Model Family: Seagate Barracuda 7200.8 family Device Model: ST3250823AS Serial Number: 3ND1GNBC Firmware Version: 3.03 User Capacity: 250,059,350,016 bytes Device is: In smartctl database [for details use: -P show] ATA Version is: 7 ATA Standard is: Exact ATA specification draft version not indicated Local Time is: Sun Apr 25 13:15:34 2010 EDT SMART support is: Available - device has SMART capability. SMART support is: Enabled === START OF READ SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED General SMART Values: Offline data collection status: (0x82) Offline data collection activity was completed without error. Auto Offline Data Collection: Enabled. Self-test execution status: ( 0) The previous self-test routine completed without error or no self-test has ever been run. Total time to complete Offline data collection: ( 430) seconds. Offline data collection capabilities: (0x5b) SMART execute Offline immediate. Auto Offline data collection on/off support. Suspend Offline collection upon new command. Offline surface scan supported. Self-test supported. No Conveyance Self-test supported. Selective Self-test supported. SMART capabilities: (0x0003) Saves SMART data before entering power-saving mode. Supports SMART auto save timer. Error logging capability: (0x01) Error logging supported. General Purpose Logging supported. Short self-test routine recommended polling time: ( 1) minutes. Extended self-test routine recommended polling time: ( 84) minutes. SMART Attributes Data Structure revision number: 10 Vendor Specific SMART Attributes with Thresholds: ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x000f 047 039 006 Pre-fail Always - 168450357 3 Spin_Up_Time 0x0003 098 098 000 Pre-fail Always - 0 4 Start_Stop_Count 0x0032 100 100 020 Old_age Always - 33 5 Reallocated_Sector_Ct 0x0033 100 100 036 Pre-fail Always - 9 7 Seek_Error_Rate 0x000f 087 060 030 Pre-fail Always - 654745480 9 Power_On_Hours 0x0032 055 055 000 Old_age Always - 40141 10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0 12 Power_Cycle_Count 0x0032 100 100 020 Old_age Always - 51 194 Temperature_Celsius 0x0022 037 062 000 Old_age Always - 37 (0 17 0 0) 195 Hardware_ECC_Recovered 0x001a 047 039 000 Old_age Always - 168450357 197 Current_Pending_Sector 0x0012 100 100 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0010 100 100 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age Always - 0 200 Multi_Zone_Error_Rate 0x0000 100 253 000 Old_age Offline - 0 202 TA_Increase_Count 0x0032 100 253 000 Old_age Always - 0 SMART Error Log Version: 1 No Errors Logged SMART Self-test log structure revision number 1 Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error # 1 Short offline Completed without error 00% 40131 - # 2 Extended offline Completed: read failure 30% 40129 379795511 # 3 Short offline Completed without error 00% 40084 - # 4 Short offline Completed without error 00% 40060 - # 5 Short offline Completed without error 00% 40036 - # 6 Short offline Completed without error 00% 40013 - # 7 Short offline Completed without error 00% 39990 - # 8 Extended offline Completed without error 00% 39977 - # 9 Short offline Completed without error 00% 39919 - #10 Short offline Completed without error 00% 39895 - #11 Short offline Completed without error 00% 39872 - #12 Short offline Completed without error 00% 39848 - #13 Short offline Completed without error 00% 39824 - #14 Short offline Completed without error 00% 39801 - #15 Extended offline Completed without error 00% 39789 - #16 Short offline Completed without error 00% 39754 - #17 Short offline Completed without error 00% 39732 - #18 Short offline Completed without error 00% 39707 - #19 Short offline Completed without error 00% 39683 - #20 Short offline Completed without error 00% 39660 - #21 Short offline Completed without error 00% 39636 - SMART Selective self-test log data structure revision number 1 SPAN MIN_LBA MAX_LBA CURRENT_TEST_STATUS 1 0 0 Not_testing 2 0 0 Not_testing 3 0 0 Not_testing 4 0 0 Not_testing 5 0 0 Not_testing Selective self-test flags (0x0): After scanning selected spans, do NOT read-scan remainder of disk. If Selective self-test is pending on power-up, resume after 0 minute delay. Given that this drive is about 4.5 years old, I am probably tempting fate by keeping it in service. SMART doesn't seem to get much respect as a reliable way to predict drive failure. What else can I use to get an early indication of drive failure?

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  • Creating Persistent Drive Labels With UDEV Using /dev/disk/by-path

    - by Matt
    I have a new BackBlaze Pod (BackBlaze Pod 2.0). It has 45 3TB drives and they when I first set it up they were labeled /dev/sda through /dev/sdz and /dev/sdaa through /dev/sdas. I used mdadm to setup three really big 15 drive RAID6 arrays. However, since first setup a few weeks ago I had a couple of the hard drives fail on me. I've replaced them but now the arrays are complaining because they can't find the missing drives. When I list the the disks... ls -l /dev/sd* I see that /dev/sda /dev/sdf /dev/sdk /dev/sdp no longer appear and now there are 4 new ones... /dev/sdau /dev/sdav /dev/sdaw /dev/sdax I also just found that I can do this... ls -l /dev/disk/by-path/ total 0 lrwxrwxrwx 1 root root 10 Sep 19 18:08 pci-0000:02:04.0-scsi-0:0:0:0 -> ../../sdau lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:02:04.0-scsi-0:1:0:0 -> ../../sdb lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:02:04.0-scsi-0:2:0:0 -> ../../sdc lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:02:04.0-scsi-0:3:0:0 -> ../../sdd lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:02:04.0-scsi-0:4:0:0 -> ../../sde lrwxrwxrwx 1 root root 10 Sep 19 18:08 pci-0000:02:04.0-scsi-2:0:0:0 -> ../../sdae lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:02:04.0-scsi-2:1:0:0 -> ../../sdg lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:02:04.0-scsi-2:2:0:0 -> ../../sdh lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:02:04.0-scsi-2:3:0:0 -> ../../sdi lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:02:04.0-scsi-2:4:0:0 -> ../../sdj lrwxrwxrwx 1 root root 10 Sep 19 18:08 pci-0000:02:04.0-scsi-3:0:0:0 -> ../../sdav lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:02:04.0-scsi-3:1:0:0 -> ../../sdl lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:02:04.0-scsi-3:2:0:0 -> ../../sdm lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:02:04.0-scsi-3:3:0:0 -> ../../sdn lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:02:04.0-scsi-3:4:0:0 -> ../../sdo lrwxrwxrwx 1 root root 10 Sep 19 18:08 pci-0000:04:04.0-scsi-0:0:0:0 -> ../../sdax lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:04:04.0-scsi-0:1:0:0 -> ../../sdq lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:04:04.0-scsi-0:2:0:0 -> ../../sdr lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:04:04.0-scsi-0:3:0:0 -> ../../sds lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:04:04.0-scsi-0:4:0:0 -> ../../sdt lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:04:04.0-scsi-2:0:0:0 -> ../../sdu lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:04:04.0-scsi-2:1:0:0 -> ../../sdv lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:04:04.0-scsi-2:2:0:0 -> ../../sdw lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:04:04.0-scsi-2:3:0:0 -> ../../sdx lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:04:04.0-scsi-2:4:0:0 -> ../../sdy lrwxrwxrwx 1 root root 9 Sep 19 18:08 pci-0000:04:04.0-scsi-3:0:0:0 -> ../../sdz I didn't list them all....you can see the problem above. They're sorted by scsi id here but sda is missing...replaced by sdau...etc... So obviously the arrays are complaining. Is it possible to get Linux to reread the drive labels in the correct order or am I screwed? My initial design with 15 drive arrays is not ideal. With 3TB drives the rebuild times were taking 3 or 4 days....maybe more. I'm scrapping the whole design and I think I am going to go with 6 x 7 RAID5 disk arrays and 3 hot spares to make the arrays a bit easier to manage and shorten the rebuild times. But I'd like to clean up the drive labels so they aren't out of order. I haven't figured out how to do this yet. Does anyone know how to get this straightened out? Thanks, Matt

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  • VFS: file-max limit 1231582 reached

    - by Rick Koshi
    I'm running a Linux 2.6.36 kernel, and I'm seeing some random errors. Things like ls: error while loading shared libraries: libpthread.so.0: cannot open shared object file: Error 23 Yes, my system can't consistently run an 'ls' command. :( I note several errors in my dmesg output: # dmesg | tail [2808967.543203] EXT4-fs (sda3): re-mounted. Opts: (null) [2837776.220605] xv[14450] general protection ip:7f20c20c6ac6 sp:7fff3641b368 error:0 in libpng14.so.14.4.0[7f20c20a9000+29000] [4931344.685302] EXT4-fs (md16): re-mounted. Opts: (null) [4982666.631444] VFS: file-max limit 1231582 reached [4982666.764240] VFS: file-max limit 1231582 reached [4982767.360574] VFS: file-max limit 1231582 reached [4982901.904628] VFS: file-max limit 1231582 reached [4982964.930556] VFS: file-max limit 1231582 reached [4982966.352170] VFS: file-max limit 1231582 reached [4982966.649195] top[31095]: segfault at 14 ip 00007fd6ace42700 sp 00007fff20746530 error 6 in libproc-3.2.8.so[7fd6ace3b000+e000] Obviously, the file-max errors look suspicious, being clustered together and recent. # cat /proc/sys/fs/file-max 1231582 # cat /proc/sys/fs/file-nr 1231712 0 1231582 That also looks a bit odd to me, but the thing is, there's no way I have 1.2 million files open on this system. I'm the only one using it, and it's not visible to anyone outside the local network. # lsof | wc 16046 148253 1882901 # ps -ef | wc 574 6104 44260 I saw some documentation saying: file-max & file-nr: The kernel allocates file handles dynamically, but as yet it doesn't free them again. The value in file-max denotes the maximum number of file- handles that the Linux kernel will allocate. When you get lots of error messages about running out of file handles, you might want to increase this limit. Historically, the three values in file-nr denoted the number of allocated file handles, the number of allocated but unused file handles, and the maximum number of file handles. Linux 2.6 always reports 0 as the number of free file handles -- this is not an error, it just means that the number of allocated file handles exactly matches the number of used file handles. Attempts to allocate more file descriptors than file-max are reported with printk, look for "VFS: file-max limit reached". My first reading of this is that the kernel basically has a built-in file descriptor leak, but I find that very hard to believe. It would imply that any system in active use needs to be rebooted every so often to free up the file descriptors. As I said, I can't believe this would be true, since it's normal to me to have Linux systems stay up for months (even years) at a time. On the other hand, I also can't believe that my nearly-idle system is holding over a million files open. Does anyone have any ideas, either for fixes or further diagnosis? I could, of course, just reboot the system, but I don't want this to be a recurring problem every few weeks. As a stopgap measure, I've quit Firefox, which was accounting for almost 2000 lines of lsof output (!) even though I only had one window open, and now I can run 'ls' again, but I doubt that will fix the problem for long. (edit: Oops, spoke too soon. By the time I finished typing out this question, the symptom was/is back) Thanks in advance for any help. And another update: My system was basically unusable, so I decided I had no option but to reboot. But before I did, I carefully quit one process at a time, checking /proc/sys/fs/file-nr after each termination. I found that, predictably, the number of open files gradually went down as I closed things down. Unfortunately, it wasn't a large effect. Yes, I was able to clear up 5000-10000 open files, but there were still over 1.2 million left. I shut down just about everything. All interactive shells, except for the one ssh I left open to finish closing down, httpd, even nfs service. Basically everything in the process table that wasn't a kernel process, and there were still an appalling number of files apparently left open. After the reboot, I found that /proc/sys/fs/file-nr showed about 2000 files open, which is much more reasonable. Starting up 2 Xvnc sessions as usual, along with the dozen or so monitoring windows I like to keep open, brought the total up to about 4000 files. I can see nothing wrong with that, of course, but I've obviously failed to identify the root cause. I'm still looking for ideas, since I definitely expect it to happen again. And another update, the next day: I watched the system carefully, and discovered that /proc/sys/fs/file-nr showed a growth of about 900 open files per hour. I shut down the system's only NFS client for the night, and the growth stopped. Mind you, it didn't free up the resources, but it did at least stop consuming more. Is this a known bug with NFS? I'll be bringing the NFS client back online today, and I'll narrow it down further. If anyone is familiar with this behavior, feel free to jump in with "Yeah, NFS4 has this problem, go back to NFS3" or something like that.

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  • Resolve Wrong IP from Domain Name only on certain networks

    - by Godric Seer
    I host a personal website on an old desktop that is LAMP based. There are several strange things about this problem so I will break it down into steps. Since I have a dynamic IP, I use no-ip to make sure I have a working domain name at all times. I use the automatic update client, but logged in and checked and my no-ip domain has the proper IP tied to it. Here is a link to the homepage through the no-ip domain for reference. Also, I do a ping and a traceroute on the no-ip domain and get: [eckertzs@localhost ~]$ ping -c 1 endradil.noip.me PING endradil.noip.me (65.24.215.99) 56(84) bytes of data. 64 bytes from endradil.noip.me (65.24.215.99): icmp_seq=1 ttl=64 time=2.23 ms --- endradil.noip.me ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 104ms rtt min/avg/max/mdev = 2.233/2.233/2.233/0.000 ms [eckertzs@localhost ~]$ traceroute endradil.noip.me traceroute to endradil.noip.me (65.24.215.99), 30 hops max, 60 byte packets 1 . (192.168.2.1) 1.755 ms 5.409 ms 5.380 ms 2 endradil.noip.me (65.24.215.99) 6.297 ms 9.543 ms 10.324 ms Using this domain, I can connect to my webserver without issue or interruption(the https is required to avoid a redirect serverside, but it works). I also have a domain I have bought on GoDaddy where I have a CNAME record forwarding the www subdomain to my no-ip domain. CNAME Record Host: www Points to: endradil.noip.me TTL: 1 hour For the past several weeks, I never had an issue using the GoDaddy domain to connect (ssh or https). As of the past few days, however, the GoDaddy domain has only worked intermittently, for a few minutes at a time and then will go down for hours at a time. I get server not found errors most of the time. Also, if I happen to be using the GoDaddy domain for an ssh connection, the connection will freeze. I have run online tests of the DNS and have seen that the website is visible by external servers and resolved to the correct IP. I also contacted GoDaddy support but they had no issues connecting to the website, and therefore did not see any issues. My personal computers (Windows desktop, linux laptop, android phone) all fail to connect when on my personal wifi. If I disconnect my phone from the wifi and use my AT&T wireless data, it can connect with both domains without issue. When I attempt to use Google webmaster tools to crawl the site using the GoDaddy domain, Google can not find the site. From my linux laptop, I have found some interesting results when I ping or traceroute the domain. The results from these: [eckertzs@localhost ~]$ ping -c 1 www.endradil.com PING www.endradil.com.Belkin (198.105.244.228) 56(84) bytes of data. --- www.endradil.com.Belkin ping statistics --- 1 packets transmitted, 0 received, 100% packet loss, time 10000ms [eckertzs@localhost ~]$ traceroute www.endradil.com traceroute to www.endradil.com (198.105.244.228), 30 hops max, 60 byte packets 1 . (192.168.2.1) 1.918 ms 2.806 ms 2.772 ms 2 cpe-65-24-208-1.insight.res.rr.com (65.24.208.1) 29.247 ms 29.654 ms 30.094 ms 3 cpe-69-23-24-117.new.res.rr.com (69.23.24.117) 15.597 ms 23.218 ms 23.581 ms 4 agg24.clmcohib01r.midwest.rr.com (65.29.1.52) 30.581 ms 30.556 ms 31.192 ms 5 be27.clevohek01r.midwest.rr.com (65.29.1.38) 30.580 ms 31.062 ms 31.038 ms 6 bu-ether25.atlngamq47w-bcr01.tbone.rr.com (107.14.19.38) 37.863 ms 68.844 ms 43.773 ms 7 107.14.17.178 (107.14.17.178) 51.866 ms 51.019 ms 50.989 ms 8 ae0.pr1.dca10.tbone.rr.com (107.14.17.200) 48.467 ms ae-4-0.a0.lax91.tbone.rr.com (66.109.1.113) 49.912 ms * 9 v413.core1.ash1.he.net (209.51.175.33) 60.270 ms 50.842 ms 50.819 ms 10 100ge5-1.core1.nyc4.he.net (184.105.223.166) 55.597 ms 56.045 ms 56.020 ms 11 xerocole-inc.10gigabitethernet12-4.core1.nyc4.he.net (216.66.41.242) 56.001 ms 55.969 ms 55.992 ms 12 * * * both show the incorrect IP. Also, the traceroute timesout on hops 12 through 255 (output truncated above). The traceroute using site24x7 works and shows reasonable results when run from their california server. From another linux box on a different network but in the same city as me (10 miles away), I still get timeout for traceroute, however the IP resolves correctly for the domain. From this I believe that the DNS result is incorrectly cached in either my router/modem or perhaps even at my ISP level. My question is, first, how do I find out exactly what is wrong, and second, how do I resolve it.

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