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• SQL Server devs–what source control system do you use, if any? (answer and maybe win free stuff)

  - by jamiet

  Recently I noticed a tweet from notable SQL Server author and community dude-at-large Steve Jones in which he asked how many SQL Server developers were putting their SQL Server source code (i.e. DDL) under source control (I’m paraphrasing because I can’t remember the exact tweet and Twitter’s search functionality is useless). The question surprised me slightly as I thought a more pertinent question would be “how many SQL Server developers are not using source control?” because I have been doing just that for many years now and I simply assumed that use of source control is a given in this day and age. Then I started thinking about it. “Perhaps I’m wrong” I pondered, “perhaps the SQL Server folks that do use source control in their day-to-day jobs are in the minority”. So, dear reader, I’m interested to know a little bit more about your use of source control. Are you putting your SQL Server code into a source control system? If so, what source control server software (e.g. TFS, Git, SVN, Mercurial, SourceSafe, Perforce) are you using? What source control client software are you using (e.g. TFS Team Explorer, Tortoise, Red Gate SQL Source Control, Red Gate SQL Connect, Git Bash, etc…)? Why did you make those particular software choices? Any interesting anecdotes to share in regard to your use of source control and SQL Server? To encourage you to contribute I have five pairs of licenses for Red Gate SQL Source Control and Red Gate SQL Connect to give away to what I consider to be the five best replies (“best” is totally subjective of course but this is my blog so my decision is final ), if you want to be considered don’t forget to leave contact details; email address, Twitter handle or similar will do. To start you off and to perhaps get the brain cells whirring, here are my answers to the questions above: Are you putting your SQL Server code into a source control system? As I think I’ve already said…yes. Always. If so, what source control server software (e.g. TFS, Git, SVN, Mercurial, SourceSafe, Perforce) are you using? I move around a lot between many clients so it changes on a fairly regular basis; my current client uses Team Foundation Server (aka TFS) and as part of a separate project is trialing the use of Team Foundation Service. I have used SVN extensively in the past which I am a fan of (I generally prefer it to TFS) and am trying to get my head around Git by using it for ObjectStorageHelper. What source control client software are you using (e.g. TFS Team Explorer, Tortoise, Red Gate SQL Source Control, Red Gate SQL Connect, Git Bash, etc…)? On my current project, Team Explorer. In the past I have used Tortoise to connect to SVN. Why did you make those particular software choices? I generally use whatever the client uses and given that I work with SQL Server I find that the majority of my clients use TFS, I guess simply because they are Microsoft development shops. Any interesting anecdotes to share in regard to your use of source control and SQL Server? Not an anecdote as such but I am going to share some frustrations about TFS. In many ways TFS is a great product because it integrates many separate functions (source control, work item tracking, build agents) into one whole and I’m firmly of the opinion that that is a good thing if for no reason other than being able to associate your check-ins with a work-item. However, like many people there are aspects to TFS source control that annoy me day-in, day-out. Chief among them has to be the fact that it uses a file’s read-only property to determine if a file should be checked-out or not and, if it determines that it should, it will happily do that check-out on your behalf without you even asking it to. I didn’t realise how ridiculous this was until I first used SVN about three years ago – with SVN you make any changes you wish and then use your source control client to determine which files have changed and thus be checked-in; the notion of “check-out” doesn’t even exist. That sounds like a small thing but you don’t realise how liberating it is until you actually start working that way. Hoping to hear some more anecdotes and opinions in the comments. Remember….free software is up for grabs! @jamiet 

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• Design a T-shirt for .NET Reflector Pro

  - by Laila

  Win a .NET Reflector Pro license, a box of Red Gate goodies, and a t-shirt printed with your design! Red Gate likes t-shirts. Each of our teams has one. In fact, each individual person has one, numbered according to when they joined the company: Red Gate's 1st, 2nd, and so on right up to Red Gate's 170th, with the slogan "More than just a number". Those t-shirts are important, chiefly because they remind the people wearing them that they are important. But that isn't enough. What really makes us great are the people who choose to use our tools. So we'd like to extend our tradition of t-shirts to include you and put the design of our next shirt entirely in your hands. We'd like you to come up with a witty slogan or create an inventive or simply beautiful t-shirt design for .NET Reflector Pro, our add-in for Visual Studio, which allows you to step into decompiled assemblies whilst debugging in Visual Studio. When you're done, post your masterpiece to Twitter with the hash tag #reflectortees, and @redgate will take a look! We'll pick the best design, and the winner will get a licensed copy of .NET Reflector Pro and a box of Red Gate goodies - not to mention a copy of their t-shirt. The winning design will go into production and be worn and given out at tradeshows, conferences, and user group events across the world, proudly bearing the name of their designer. We'll also pick three runners-up who will receive licenses for .NET Reflector Pro. Red Gate goodie box Interested? If you're up for the challenge, then we've got some resources to get you started. Inside the .zip file you'll find high-quality versions of the following: T-shirt templates: don't forget to design the front and the back! Different versions of the .NET Reflector Pro logo and Red Gate logo. Colour sheets to give you an easy reference to the Red Gate colours, including hex and RGB values. You can create and send us as many designs as you like, and each of them will be considered for the prize. To submit your designs, simply tweet including the competition hash tag, #reflectortees, and a link to somewhere we can see your design: either an image hosting site such as Twitpic, Flickr or Picasa, or a personal blog. You will need to create a Twitter account (which is free), if you don't already have one. You only have three limits: The background colour of the t-shirt should be one of our brand colours (red, light/dark grey or black), though you're welcome to use other colours in the rest of the design. You need to make use of either the .NET Reflector Pro logo OR the Red Gate logo (please keep them as they are) If you include any text or slogan, stick with just one or two colors for it. Apart from that, go wild. Go and do whatever it is you do when you get creative: whether you walk barefoot on the grass with a pencil and paper, sit cross-legged on a pile of cushions with a laptop, or simply close your eyes and float through a mist of ideas, now is your chance. Make sure you enjoy it. We're looking forward to seeing your creations. Terms and conditions 1. The closing date for entries is June 11th, 2010 (4 p.m. UK time). Red Gate Software Ltd reserves the right to extend the competition deadline at its discretion. If there is a revision, the revised date will be published on this blog and the date for announcing the results will be postponed accordingly. 2. The winning designer will be notified on June 14th, 2010 through Twitter. The winner must claim his/her prize by sending us a high-resolution image of their design via email (i.e. Illustrator EPS files or appropriate format, ideally at 300dpi). If the winner does not come forward within 3 days of the announcement, they will forfeit their prize and another winner will be selected from the runners-up. The names of the winner and runners-up will be posted on this blog by June 18th.  3. Entry is completed on the designer posting a link to their entry in a tweet with the correct hash tag, #reflectortees. 4. Red Gate Software needs to hold the rights to using the winning design in order to put the t-shirt into production. We will make sure that this is fine with the winner before we do so, but if you do not want us holding the rights to your design, please do not submit your designs. We reserve the right to slightly alter or adjust any artwork we decide to use (mainly to make it easier to print), but we will make sure we contact the winner for approval first. The winner will also need to allow us the use of his/her name for purposes of promoting your design. 5. Entries must be entirely your own original work and must not breach any copyright or third party rights. Red Gate Software Ltd will not be made partially or fully liable for any non-original work submitted by you. 6. This competition is free: you do not need to buy anything or be an existing customer to enter. 7. This competition is not open to employees of Red Gate Software Ltd, their families, or any other company directly connected with the administration of this promotion.

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• Why lock-free data structures just aren't lock-free enough

  - by Alex.Davies

  Today's post will explore why the current ways to communicate between threads don't scale, and show you a possible way to build scalable parallel programming on top of shared memory. The problem with shared memory Soon, we will have dozens, hundreds and then millions of cores in our computers. It's inevitable, because individual cores just can't get much faster. At some point, that's going to mean that we have to rethink our architecture entirely, as millions of cores can't all access a shared memory space efficiently. But millions of cores are still a long way off, and in the meantime we'll see machines with dozens of cores, struggling with shared memory. Alex's tip: The best way for an application to make use of that increasing parallel power is to use a concurrency model like actors, that deals with synchronisation issues for you. Then, the maintainer of the actors framework can find the most efficient way to coordinate access to shared memory to allow your actors to pass messages to each other efficiently. At the moment, NAct uses the .NET thread pool and a few locks to marshal messages. It works well on dual and quad core machines, but it won't scale to more cores. Every time we use a lock, our core performs an atomic memory operation (eg. CAS) on a cell of memory representing the lock, so it's sure that no other core can possibly have that lock. This is very fast when the lock isn't contended, but we need to notify all the other cores, in case they held the cell of memory in a cache. As the number of cores increases, the total cost of a lock increases linearly. A lot of work has been done on "lock-free" data structures, which avoid locks by using atomic memory operations directly. These give fairly dramatic performance improvements, particularly on systems with a few (2 to 4) cores. The .NET 4 concurrent collections in System.Collections.Concurrent are mostly lock-free. However, lock-free data structures still don't scale indefinitely, because any use of an atomic memory operation still involves every core in the system. A sync-free data structure Some concurrent data structures are possible to write in a completely synchronization-free way, without using any atomic memory operations. One useful example is a single producer, single consumer (SPSC) queue. It's easy to write a sync-free fixed size SPSC queue using a circular buffer*. Slightly trickier is a queue that grows as needed. You can use a linked list to represent the queue, but if you leave the nodes to be garbage collected once you're done with them, the GC will need to involve all the cores in collecting the finished nodes. Instead, I've implemented a proof of concept inspired by this intel article which reuses the nodes by putting them in a second queue to send back to the producer. * In all these cases, you need to use memory barriers correctly, but these are local to a core, so don't have the same scalability problems as atomic memory operations. Performance tests I tried benchmarking my SPSC queue against the .NET ConcurrentQueue, and against a standard Queue protected by locks. In some ways, this isn't a fair comparison, because both of these support multiple producers and multiple consumers, but I'll come to that later. I started on my dual-core laptop, running a simple test that had one thread producing 64 bit integers, and another consuming them, to measure the pure overhead of the queue. So, nothing very interesting here. Both concurrent collections perform better than the lock-based one as expected, but there's not a lot to choose between the ConcurrentQueue and my SPSC queue. I was a little disappointed, but then, the .NET Framework team spent a lot longer optimising it than I did. So I dug out a more powerful machine that Red Gate's DBA tools team had been using for testing. It is a 6 core Intel i7 machine with hyperthreading, adding up to 12 logical cores. Now the results get more interesting. As I increased the number of producer-consumer pairs to 6 (to saturate all 12 logical cores), the locking approach was slow, and got even slower, as you'd expect. What I didn't expect to be so clear was the drop-off in performance of the lock-free ConcurrentQueue. I could see the machine only using about 20% of available CPU cycles when it should have been saturated. My interpretation is that as all the cores used atomic memory operations to safely access the queue, they ended up spending most of the time notifying each other about cache lines that need invalidating. The sync-free approach scaled perfectly, despite still working via shared memory, which after all, should still be a bottleneck. I can't quite believe that the results are so clear, so if you can think of any other effects that might cause them, please comment! Obviously, this benchmark isn't realistic because we're only measuring the overhead of the queue. Any real workload, even on a machine with 12 cores, would dwarf the overhead, and there'd be no point worrying about this effect. But would that be true on a machine with 100 cores? Still to be solved. The trouble is, you can't build many concurrent algorithms using only an SPSC queue to communicate. In particular, I can't see a way to build something as general purpose as actors on top of just SPSC queues. Fundamentally, an actor needs to be able to receive messages from multiple other actors, which seems to need an MPSC queue. I've been thinking about ways to build a sync-free MPSC queue out of multiple SPSC queues and some kind of sign-up mechanism. Hopefully I'll have something to tell you about soon, but leave a comment if you have any ideas.

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• Understanding each other in web development

  - by Pete Hotchkin

  During my career I have been lucky enough to work in several different roles within web development with many extremely talented people, from incredible designers who were passionate about the placement of every pixel right through to server administrators and DBAs who were always measuring the improvements they were making to their queries in the smallest possible unit. The problem I always faced was that more often than not I was stuck in the middle trying to mediate between these different functions and enable each side to understand the other’s point of view. The main areas of contention that there have always been between these functional groups in my experience have been at 2 key points: during the build phase and then when there is a problem post-build. During both of these times it is often easier for someone to pass the buck onto someone else than spend the time to understand the other person’s perspective. Below is a quick look at two upcoming tools that will not only speed up the build phase for each function, but  also help when it comes to the issues faced once a site has been pushed live. In my experience a web project goes through several phases of development. The first of these is design, generally handled as Photoshop files which are then passed onto a front-end developer. This is the first point at which heated discussions can arise. One problem I’ve seen several times is that the designer doesn’t fully understand the platform constraints that need to be considered, and as a result has designed something that does not translate very well or is simply not possible. Working at Red Gate, I am lucky enough to be able to meet some amazing people and this happened just the other day when I was introduced to Neil Kinnish and Pete Nelson, the creators of what I believe could be a great asset in this designer-developer relationship, Mixture. Mixture allows the front end developer to quickly prototype a web page with built-in frameworks such as bootstrap. It’s not an IDE however, it just sits there in the background and monitors the project files in the background so every time you save a file from your favorite IDE, it will compile things like LESS, compact your JavaScript and the automatically refresh your test browser so you can see the changes instantly. I think one of the best parts of this however is a single button that pushes the changed files up to the web so the designer can instantly see how far the developer has got and the problem that he is facing at that time without the need to spend time setting up a remote server. I can see this being a real asset to remote teams where there needs to be a compromise between the designer and the front-end developer, or just to allow the designer to see how the build is progressing and suggest small alterations. Once the design has been built into the front end the designer’s job is generally done and there are no other points of contention between the designer and the other functions involved in building these web projects. As the project moves into the stage of integrating it into the back end and deploying it to the production server other functions start to be pulled in and other issues arise such as the back-end developer understanding the frameworks that they are using such as the routes that are in place in an MVC application or the number of database calls that the ORM layer is actually making. There are many tools out there that can actually help with these problems such as mini profiler that gives you a quick snapshot of what is going on directly in the browser. For a slightly more in-depth look at what is happening and to gain a deeper understanding of an application you may be working on though, you may want to consider Glimpse. Created by Nik and Anthony, it is an application that sits at the bottom of your browser (installed via NuGet) which can show you information about how your application is pieced together and how the information on screen is being delivered as it happens. With a wealth of community-built plugins such as one for nHibernate and linq2SQL (full list of plugins on NuGet). It can be customized directly to your own setup to truly delve into the code to see what is happening, and can help to reduce the number of confusing moments about whether it is your code that is going wrong or whether there is something more sinister happening directly on the server. All the tools that I have mentioned in this post help to do one thing above all, and that is to ease the barrier of understanding between the different functions that are involved in building and maintaining a web application. In my experience it is very easy to say “Well, that’s not my problem”, simply because the two functions involved don’t truly understand the other’s point of view. Software should not only be seen as a way to streamline our own working process or as a debugging tool but also a communication aid to improve the entire lifecycle of a web project. Glimpse is actually the project that I am the designer on and I would love to get your feedback if you do decide to try it out or if you would like to share your own experiences of working on web projects please fill in your details at https://www.surveymk.com/s/joinGlimpse  or add a comment below and I will get in touch with you.

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• Querying Visual Studio project files using T-SQL and Powershell

  - by jamiet

  Earlier today I had a need to get some information out of a Visual Studio project file and in this blog post I’m going to share a couple of ways of going about that because I’m pretty sure I won’t be the only person that ever wants to do this. The specific problem I was trying to solve was finding out how many objects in my database project (i.e. in my .dbproj file) had any warnings suppressed but the techniques discussed below will work pretty well for any Visual Studio project file because every such file is simply an XML document, hence it can be queried by anything that can query XML documents. Ever heard the phrase “when all you’ve got is hammer everything looks like a nail”? Well that’s me with querying stuff – if I can write SQL then I’m writing SQL. Here’s a little noddy database project I put together for demo purposes: Two views and a stored procedure, nothing fancy. I suppressed warnings for [View1] & [Procedure1] and hence the pertinent part my project file looks like this:   <ItemGroup>    <Build Include="Schema Objects\Schemas\dbo\Views\View1.view.sql">      <SubType>Code</SubType>      <SuppressWarnings>4151,3276</SuppressWarnings>    </Build>    <Build Include="Schema Objects\Schemas\dbo\Views\View2.view.sql">      <SubType>Code</SubType>    </Build>    <Build Include="Schema Objects\Schemas\dbo\Programmability\Stored Procedures\Procedure1.proc.sql">      <SubType>Code</SubType>      <SuppressWarnings>4151</SuppressWarnings>    </Build>  </ItemGroup>  <ItemGroup> Note the <SuppressWarnings> elements – those are the bits of information that I am after. With a lot of help from folks on the SQL Server XML forum  I came up with the following query that nailed what I was after. It reads the contents of the .dbproj file into a variable of type XML and then shreds it using T-SQL’s XML data type methods: DECLARE @xml XML; SELECT @xml = CAST(pkgblob.BulkColumn AS XML) FROM   OPENROWSET(BULK 'C:\temp\QueryingProjectFileDemo\QueryingProjectFileDemo.dbproj' -- <-Change this path!                    ,single_blob) AS pkgblob                    ;WITH XMLNAMESPACES( 'http://schemas.microsoft.com/developer/msbuild/2003' AS ns) SELECT  REVERSE(SUBSTRING(REVERSE(ObjectPath),0,CHARINDEX('\',REVERSE(ObjectPath)))) AS [ObjectName]        ,[SuppressedWarnings] FROM   (        SELECT  build.query('.') AS [_node]        ,       build.value('ns:SuppressWarnings[1]','nvarchar(100)') AS [SuppressedWarnings]        ,       build.value('@Include','nvarchar(1000)') AS [ObjectPath]        FROM    @xml.nodes('//ns:Build[ns:SuppressWarnings]') AS R(build)        )q And here’s the output: And that’s it – an easy way of discovering which warnings have been suppressed and for which objects in your database projects. I won’t bother going over the code as it is fairly self-explanatory – peruse it at your leisure.   Once I had the SQL above I figured I’d share it around a little in case it was ever useful to anyone else; hence I’m writing this blog post and I also posted it on the Visual Studio Database Development Tools forum at FYI: Discover which objects have had warnings suppressed. Luckily Kevin Goode saw the thread and he posted a different solution to the same problem, one that uses Powershell. The advantage of Kevin’s Powershell approach is that it is easy to analyse many .dbproj files at the same time. Below is Kevin’s code which I have tweaked ever so slightly so that it produces the same results as my SQL script (I just want any object that had had a warning suppressed whereas Kevin was querying specifically for warning 4151):   cd 'C:\Temp\QueryingProjectFileDemo\' cls $projects = ls -r -i *.dbproj Foreach($project in $projects) { $xml = new-object System.Xml.XmlDocument $xml.set_PreserveWhiteSpace( $true ) $xml.Load($project) #$xpath = @{Start="/e:Project/e:ItemGroup/e:Build[e:SuppressWarnings=4151]/@Include"} #$xpath = @{Start="/e:Project/e:ItemGroup/e:Build[contains(e:SuppressWarnings,'4151')]/@Include"} $xpath = @{Start="/e:Project/e:ItemGroup/e:Build[e:SuppressWarnings]/@Include"} $ns = @{ e = "http://schemas.microsoft.com/developer/msbuild/2003" } $xml | Select-Xml -XPath $xpath.Start -Namespace $ns |Select -Expand Node | Select -expand Value } and here’s the output: Nice reusable Powershell and SQL scripts – not bad for an evening’s work. Thank you to Kevin for allowing me to share his code. Don’t forget that these techniques can easily be adapted to query any Visual Studio project file, they’re only XML documents after all! Doubtless many people out there already have code for doing this but nonetheless here is another offering to the great script library in the sky. Have fun! @Jamiet

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• Frameskipping in Android gameloop causing choppy sprites (Open GL ES 2.0)

  - by user22241

  I have written a simple 2d platform game for Android and am wondering how one deals with frame-skipping? Are there any alternatives? Let me explain further. So, my game loop allows for the rendering to be skipped if game updates and rendering do not fit into my fixed time-slice (16.667ms). This allows my game to run at identically perceived speeds on different devices. And this works great, things do run at the same speed. However, when the gameloop skips a render call for even one frame, the sprite glitches. And thinking about it, why wouldn't it? You're seeing a sprite move say, an average of 10 pixels every 1.6 seconds, then suddenly, there is a pause of 3.2ms, and the sprite then appears to jump 20 pixels. When this happens 3 or 4 times in close succession, the result is very ugly and not something I want in my game. Therfore, my question is how does one deal with these 'pauses' and 'jumps' - I've read every article on game loops I can find (see below) and my loops are even based off of code from these articles. The articles specifically mention frame skipping but they don't make any reference to how to deal with visual glitches that result from it. I've attempted various game-loops. My loop must have a mechanism in-place to allow rendering to be skipped to keep game-speed constant across multiple devices (or alternative, if one exists) I've tried interpolation but this doesn't eliminate this specific problem (although it looks like it may mitigate the issue slightly as when it eventually draws the sprite it 'moves it back' between the old and current positions so the 'jump' isn't so big. I've also tried a form of extrapolation which does seem to keep things smooth considerably, but I find it to be next to completely useless because it plays havoc with my collision detection (even when drawing with a 'display only' coordinate - see extrapolation-breaks-collision-detection) I've tried a loop that uses Thread.sleep when drawing / updating completes with time left over, no frame skipping in this one, again fairly smooth, but runs differently on different devices so no good. And I've tried spawning my own, third thread for logic updates, but this, was extremely messy to deal with and the performance really wasn't good. (upon reading tons of forums, most people seem to agree a 2 thread loops ( so UI and GL threads) is safer / easier). Now if I remove frame skipping, then all seems to run nice and smooth, with or without inter/extrapolation. However, this isn't an option because the game then runs at different speeds on different devices as it falls behind from not being able to render fast enough. I'm running logic at 60 Ticks per second and rendering as fast as I can. I've read, as far as I can see every article out there, I've tried the loops from My Secret Garden and Fix your timestep. I've also read: Against the grain deWITTERS Game Loop Plus various other articles on Game-loops. A lot of the others are derived from the above articles or just copied word for word. These are all great, but they don't touch on the issues I'm experiencing. I really have tried everything I can think of over the course of a year to eliminate these glitches to no avail, so any and all help would be appreciated. A couple of examples of my game loops (Code follows): From My Secret Room public void onDrawFrame(GL10 gl) { //Rre-set loop back to 0 to start counting again loops=0; while(System.currentTimeMillis() > nextGameTick && loops < maxFrameskip) { SceneManager.getInstance().getCurrentScene().updateLogic(); nextGameTick += skipTicks; timeCorrection += (1000d / ticksPerSecond) % 1; nextGameTick += timeCorrection; timeCorrection %= 1; loops++; } extrapolation = (float)(System.currentTimeMillis() + skipTicks - nextGameTick) / (float)skipTicks; render(extrapolation); } And from Fix your timestep double t = 0.0; double dt2 = 0.01; double currentTime = System.currentTimeMillis()*0.001; double accumulator = 0.0; double newTime; double frameTime; @Override public void onDrawFrame(GL10 gl) { newTime = System.currentTimeMillis()*0.001; frameTime = newTime - currentTime; if ( frameTime > (dt*5)) //Allow 5 'skips' frameTime = (dt*5); currentTime = newTime; accumulator += frameTime; while ( accumulator >= dt ) { SceneManager.getInstance().getCurrentScene().updateLogic(); previousState = currentState; accumulator -= dt; } interpolation = (float) (accumulator / dt); render(interpolation); }

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• The Case of the Extra Page: Rendering Reporting Services as PDF

  - by smisner

  I had to troubleshoot a problem with a mysterious extra page appearing in a PDF this week. My first thought was that it was likely to caused by one of the most common problems that people encounter when developing reports that eventually get rendered as PDF is getting blank pages inserted into the PDF document. The cause of the blank pages is usually related to sizing. You can learn more at Understanding Pagination in Reporting Services in Books Online. When designing a report, you have to be really careful with the layout of items in the body. As you move items around, the body will expand to accommodate the space you're using and you might eventually tighten everything back up again, but the body doesn't automatically collapse. One of my favorite things to do in Reporting Services 2005 - which I dubbed the "vacu-pack" method - was to just erase the size property of the Body and let it auto-calculate the new size, squeezing out all the extra space. Alas, that method no longer works beginning with Reporting Services 2008. Even when you make sure the body size is as small as possible (with no unnecessary extra space along the top, bottom, left, or right side of the body), it's important to calculate the body size plus header plus footer plus the margins and ensure that the calculated height and width do not exceed the report's height and width (shown as the page in the illustration above). This won't matter if users always render reports online, but they'll get extra pages in a PDF document if the report's height and width are smaller than the calculate space. Beginning the Investigation In the situation that I was troubleshooting, I checked the properties: Item Property Value Body Height 6.25in   Width 10.5in Page Header Height 1in Page Footer Height 0.25in Report Left Margin 0.1in   Right Margin 0.1in   Top Margin 0.05in   Bottom Margin 0.05in   Page Size - Height 8.5in   Page Size - Width 11in So I calculated the total width using Body Width + Left Margin + Right Margin and came up with a value of 10.7 inches. And then I calculated the total height using Body Height + Page Header Height + Page Footer Height + Top Margin + Bottom Margin and got 7.6 inches. Well, page sizing couldn't be the reason for the extra page in my report because 10.7 inches is smaller than the report's width of 11 inches and 7.6 inches is smaller than the report's height of 8.5 inches. I had to look elsewhere to find the culprit. Conducting the Third Degree My next thought was to focus on the rendering size of the items in the report. I've adapted my problem to use the Adventure Works database. At the top of the report are two charts, and then below each chart is a rectangle that contains a table. In the real-life scenario, there were some graphics present as a background for the tables which fit within the rectangles that were about 3 inches high so the visual space of the rectangles matched the visual space of the charts - also about 3 inches high. But there was also a huge amount of white space at the bottom of the page, and as I mentioned at the beginning of this post, a second page which was blank except for the footer that appeared at the bottom. Placing a textbox beneath the rectangles to see if they would appear on the first page resulted the textbox's appearance on the second page. For some reason, the rectangles wanted a buffer zone beneath them. What's going on? Taking the Suspect into Custody My next step was to see what was really going on with the rectangle. The graphic appeared to be correctly sized, but the behavior in the report indicated the rectangle was growing. So I added a border to the rectangle to see what it was doing. When I added borders, I could see that the size of each rectangle was growing to accommodate the table it contains. The rectangle on the right is slightly larger than the one on the left because the table on the right contains an extra row. The rectangle is trying to preserve the whitespace that appears in the layout, as shown below. Closing the Case Now that I knew what the problem was, what could I do about it? Because of the graphic in the rectangle (not shown), I couldn't eliminate the use of the rectangles and just show the tables. But fortunately, there is a report property that comes to the rescue: ConsumeContainerWhitespace (accessible only in the Properties window). I set the value of this property to True. Problem solved. Now the rectangles remain fixed at the configured size and don't grow vertically to preserve the whitespace. Case closed.

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• Joins in single-table queries

  - by Rob Farley

  Tables are only metadata. They don’t store data. I’ve written something about this before, but I want to take a viewpoint of this idea around the topic of joins, especially since it’s the topic for T-SQL Tuesday this month. Hosted this time by Sebastian Meine (@sqlity), who has a whole series on joins this month. Good for him – it’s a great topic. In that last post I discussed the fact that we write queries against tables, but that the engine turns it into a plan against indexes. My point wasn’t simply that a table is actually just a Clustered Index (or heap, which I consider just a special type of index), but that data access always happens against indexes – never tables – and we should be thinking about the indexes (specifically the non-clustered ones) when we write our queries. I described the scenario of looking up phone numbers, and how it never really occurs to us that there is a master list of phone numbers, because we think in terms of the useful non-clustered indexes that the phone companies provide us, but anyway – that’s not the point of this post. So a table is metadata. It stores information about the names of columns and their data types. Nullability, default values, constraints, triggers – these are all things that define the table, but the data isn’t stored in the table. The data that a table describes is stored in a heap or clustered index, but it goes further than this. All the useful data is going to live in non-clustered indexes. Remember this. It’s important. Stop thinking about tables, and start thinking about indexes. So let’s think about tables as indexes. This applies even in a world created by someone else, who doesn’t have the best indexes in mind for you. I’m sure you don’t need me to explain Covering Index bit – the fact that if you don’t have sufficient columns “included” in your index, your query plan will either have to do a Lookup, or else it’ll give up using your index and use one that does have everything it needs (even if that means scanning it). If you haven’t seen that before, drop me a line and I’ll run through it with you. Or go and read a post I did a long while ago about the maths involved in that decision. So – what I’m going to tell you is that a Lookup is a join. When I run SELECT CustomerID FROM Sales.SalesOrderHeader WHERE SalesPersonID = 285; against the AdventureWorks2012 get the following plan: I’m sure you can see the join. Don’t look in the query, it’s not there. But you should be able to see the join in the plan. It’s an Inner Join, implemented by a Nested Loop. It’s pulling data in from the Index Seek, and joining that to the results of a Key Lookup. It clearly is – the QO wouldn’t call it that if it wasn’t really one. It behaves exactly like any other Nested Loop (Inner Join) operator, pulling rows from one side and putting a request in from the other. You wouldn’t have a problem accepting it as a join if the query were slightly different, such as SELECT sod.OrderQty FROM Sales.SalesOrderHeader AS soh JOIN Sales.SalesOrderDetail as sod on sod.SalesOrderID = soh.SalesOrderID WHERE soh.SalesPersonID = 285; Amazingly similar, of course. This one is an explicit join, the first example was just as much a join, even thought you didn’t actually ask for one. You need to consider this when you’re thinking about your queries. But it gets more interesting. Consider this query: SELECT SalesOrderID FROM Sales.SalesOrderHeader WHERE SalesPersonID = 276 AND CustomerID = 29522; It doesn’t look like there’s a join here either, but look at the plan. That’s not some Lookup in action – that’s a proper Merge Join. The Query Optimizer has worked out that it can get the data it needs by looking in two separate indexes and then doing a Merge Join on the data that it gets. Both indexes used are ordered by the column that’s indexed (one on SalesPersonID, one on CustomerID), and then by the CIX key SalesOrderID. Just like when you seek in the phone book to Farley, the Farleys you have are ordered by FirstName, these seek operations return the data ordered by the next field. This order is SalesOrderID, even though you didn’t explicitly put that column in the index definition. The result is two datasets that are ordered by SalesOrderID, making them very mergeable. Another example is the simple query SELECT CustomerID FROM Sales.SalesOrderHeader WHERE SalesPersonID = 276; This one prefers a Hash Match to a standard lookup even! This isn’t just ordinary index intersection, this is something else again! Just like before, we could imagine it better with two whole tables, but we shouldn’t try to distinguish between joining two tables and joining two indexes. The Query Optimizer can see (using basic maths) that it’s worth doing these particular operations using these two less-than-ideal indexes (because of course, the best indexese would be on both columns – a composite such as (SalesPersonID, CustomerID – and it would have the SalesOrderID column as part of it as the CIX key still). You need to think like this too. Not in terms of excusing single-column indexes like the ones in AdventureWorks2012, but in terms of having a picture about how you’d like your queries to run. If you start to think about what data you need, where it’s coming from, and how it’s going to be used, then you will almost certainly write better queries. …and yes, this would include when you’re dealing with regular joins across multiples, not just against joins within single table queries.

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• Record Screen Activity with CamStudio

  - by Asian Angel

  Sometimes a visual demonstration works much better than a list of instructions. If you need to make a demo video for family and/or friends then you might want to have a look at CamStudio. Using CamStudio To get properly set up you will need to install two different files (the main program followed by the codec). Once that is done you are ready to get started. When you start the program you will see a surprisingly small window. Notice the highlighted Record to text…it serves as a visual indicator for the video type selected for recording. Before you start creating a video it would be a good idea to look through some of the settings. The first one to look at is the region or area that you want to record. Next you will want to look through the video options since these will affect the quality and final size of your video files. The default setting for quality is 70…adjust that to the level that best suits your needs. Note: For our example we maxed out the various video settings for best quality. On our system Microsoft Video 1 was listed as the default compressor but as you can see there were other options available. You can configure the settings for the compressor you want to use if desired. Keep in mind that each compressor will have unique settings of their own, so if you change it, be certain to go back and check. We decided to use the CamStudio Lossless Codec for our example (it gave the best results while trying the software). Going back to the main window you can toggle back and forth between .avi and .swf output using the last button. Once you are satisfied with the settings click on the red record button to start. If you need to pause while recording or stop recording click on the system tray icon and select the appropriate command. When you are finished recording, you will be presented with the save file window. Browse for the desired save location and name your new file. Once you have saved the file the movie player window will automatically open so that you view your new video. Our sample video shown here is at 50% of original size so may look slightly “gritty”. The detail was much better at 100%. If you decide to record and save as .swf the process will be identical to recording in .avi format until the movie player window opens. At that time the conversion process from .avi to .swf will begin. When complete you will have a new flash video and html file that goes with it. Depending on which browser you have set as default, you may run into a small problem when the preview for your new .swf file tries to open. There is a small bug in the generated html file. You can use this work-around or… Just open the .swf file directly in your favorite browser. Conclusion CamStudio may not produce the highest quality videos, but it’s free and does a very nice job nonetheless. If you are working on a tight budget or only need to make an occasional video then CamStudio is a very sensible choice. Links Download CamStudio Stable Version & CamStudio Codec *Download links are approximately half-way down the page. Download CamStudio Stable Version & CamStudio Codec at SourceForge *Beta version also available here. Similar Articles Productive Geek Tips Get the Classic Style Network Activity Indicator Back in Windows 7How To Copy a DVD with VLC 1.0ALLCapture 3.0 [Review]Listen and Record Over 12,000 Online Radio Stations with RadioSureGeek Reviews: Play And Record Internet Radio With Screamer Radio TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Xobni Plus for Outlook All My Movies 5.9 CloudBerry Online Backup 1.5 for Windows Home Server Snagit 10 TimeToMeet is a Simple Online Meeting Planning Tool Easily Create More Bookmark Toolbars in Firefox Filevo is a Cool File Hosting & Sharing Site Get a free copy of WinUtilities Pro 2010 World Cup Schedule Boot Snooze – Reboot and then Standby or Hibernate

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• What should you bring to the table as a Software Architect?

  - by Ahmad Mageed

  There have been many questions with good answers about the role of a Software Architect (SA) on StackOverflow and Programmers SE. I am trying to ask a slightly more focused question than those. The very definition of a SA is broad so for the sake of this question let's define a SA as follows: A Software Architect guides the overall design of a project, gets involved with coding efforts, conducts code reviews, and selects the technologies to be used. In other words, I am not talking about managerial rest and vest at the crest (further rhyming words elided) types of SAs. If I were to pursue any type of SA position I don't want to be away from coding. I might sacrifice some time to interface with clients and Business Analysts etc., but I am still technically involved and I'm not just aware of what's going on through meetings. With these points in mind, what should a SA bring to the table? Should they come in with a mentality of "laying down the law" (so to speak) and enforcing the usage of certain tools to fit "their way," i.e., coding guidelines, source control, patterns, UML documentation, etc.? Or should they specify initial direction and strategy then be laid back and jump in as needed to correct the ship's direction? Depending on the organization this might not work. An SA who relies on TFS to enforce everything may struggle to implement their plan at an employer that only uses StarTeam. Similarly, an SA needs to be flexible depending on the stage of the project. If it's a fresh project they have more choices, whereas they might have less for existing projects. Here are some SA stories I have experienced as a way of sharing some background in hopes that answers to my questions might also shed some light on these issues: I've worked with an SA who code reviewed literally every single line of code of the team. The SA would do this for not just our project but other projects in the organization (imagine the time spent on this). At first it was useful to enforce certain standards, but later it became crippling. FxCop was how the SA would find issues. Don't get me wrong, it was a good way to teach junior developers and force them to think of the consequences of their chosen approach, but for senior developers it was seen as somewhat draconian. One particular SA was against the use of a certain library, claiming it was slow. This forced us to write tons of code to achieve things differently while the other library would've saved us a lot of time. Fast forward to the last month of the project and the clients were complaining about performance. The only solution was to change certain functionality to use the originally ignored approach despite early warnings from the devs. By that point a lot of code was thrown out and not reusable, leading to overtime and stress. Sadly the estimates used for the project were based on the old approach which my project was forbidden from using so it wasn't an appropriate indicator for estimation. I would hear the PM say "we've done this before," when in reality they had not since we were using a new library and the devs working on it were not the same devs used on the old project. The SA who would enforce the usage of DTOs, DOs, BOs, Service layers and so on for all projects. New devs had to learn this architecture and the SA adamantly enforced usage guidelines. Exceptions to usage guidelines were made when it was absolutely difficult to follow the guidelines. The SA was grounded in their approach. Classes for DTOs and all CRUD operations were generated via CodeSmith and database schemas were another similar ball of wax. However, having used this setup everywhere, the SA was not open to new technologies such as LINQ to SQL or Entity Framework. I am not using this post as a platform for venting. There were positive and negative aspects to my experiences with the SA stories mentioned above. My questions boil down to: What should an SA bring to the table? How can they strike a balance in their decision making? Should one approach an SA job (as defined earlier) with the mentality that they must enforce certain ground rules? Anything else to consider? Thanks! I'm sure these job tasks are easily extended to people who are senior devs or technical leads, so feel free to answer at that capacity as well.

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• Justifiable Perks.

  - by Phil Factor

      I was once the director of a start-up IT Company, and had the task of recruiting a proportion of the management team. As my background was in IT management, I was rather more familiar with recruiting Geeks for technology jobs, but here, one of my early tasks was interviewing a Marketing Director.  The small group of financiers had suggested a rather strange Irishman called  Halleran.  From my background in City of London dealing-rooms, I was slightly unprepared for the experience of interviewing anyone wearing a pink suit. Many of my older City colleagues would have required resuscitation after seeing his white leather shoes. However, nobody will accuse me of prejudging an interviewee. After all, many Linux experts who I’ve come to rely on have appeared for interview dressed as hobbits. In fact, the interview went well, and we had even settled his salary.  I was somewhat unprepared for the coda.    ‘And I will need to be provided with a Ferrari  by the company.’    ‘Hmm. That seems reasonable.’    Initially, he looked startled, and then a slow smile of victory spread across his face.    ‘What colour would you like?’ I asked genially.    ‘It has to be red.’ He looked very earnest on this point.    ‘Fine. I have to go past Hamleys on the way home this evening, so I’ll pick one up then for you.’    ‘Er.. Hamley’s is a toyshop, not a Ferrari Dealership.’    I stared at him in bafflement for a few seconds. ‘You’re not seriously asking for a real Ferrari are you?’     ‘Well, yes. Not for my own sake, you understand. I’d much prefer a simple run-about, but my position demands it. How could I maintain the necessary status in the office without one? How could I do my job in marketing when my grey Datsun was all too visible in the car Park? It is a tool of the job.’    ‘Excuse me a moment, but I must confer with the MD’    I popped out to see Chris, the MD. ‘Chris, I’m interviewing a lunatic in a pink suit who is trying to demand that a Ferrari is a precondition of his employment. I tried the ‘misunderstanding trick’ but it didn’t faze him.’     ‘Sorry, Phil, but we’ve got to hire him. The VCs insist on it. You’ve got to think of something that doesn’t involve committing to the purchase of a Ferrari. Current funding barely covers the rent for the building.’    ‘OK boss. Leave it to me.’    On return, I slapped O’Halleran’s file on the table with a genial, paternalistic smile. ‘Of course you should have a Ferrari. The only trouble is that it will require a justification document that can be presented to the board. I’m sure you’ll have no problem in preparing this document in the required format.’ The initial look of despair was quickly followed by a bland look of acquiescence. He had, earlier in the interview, argued with great eloquence his skill in preparing the tiresome documents that underpin the essential corporate and government deals that were vital to the success of this new enterprise. The justification of a Ferrari should be a doddle.     After the interview, Chris nervously asked how I’d fared.     ‘I think it is all solved.’    ‘… without promising a Ferrari, I hope.’    ‘Well, I did actually; on condition he justified it in writing.’    Chris issued a stream of invective. The strain of juggling the resources in an underfunded startup was beginning to show.    ‘Don’t worry. In the unlikely event of him coming back with the required document, I’ll give him mine.’    ‘Yours?’ He strode over to the window to stare down at the car park.    He needn’t have worried: I knew that his breed of marketing man could more easily lay an ostrich egg than to prepare a decent justification document. My Ferrari is still there at the back of my garage. Few know of the Ferrari cultivator, a simple inexpensive motorized device designed for the subsistence farmers of southern Italy. It is the very devil to start, but it creates a perfect tilth for the seedbed.

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• WPF: Timers

  - by Ilya Verbitskiy

  I believe, once your WPF application will need to execute something periodically, and today I would like to discuss how to do that. There are two possible solutions. You can use classical System.Threading.Timer class or System.Windows.Threading.DispatcherTimer class, which is the part of WPF. I have created an application to show you how to use the API.     Let’s take a look how you can implement timer using System.Threading.Timer class. First of all, it has to be initialized.   1: private Timer timer; 2:   3: public MainWindow() 4: { 5: // Form initialization code 6: 7: timer = new Timer(OnTimer, null, Timeout.InfiniteTimeSpan, Timeout.InfiniteTimeSpan); 8: }   Timer’s constructor accepts four parameters. The first one is the callback method which is executed when timer ticks. I will show it to you soon. The second parameter is a state which is passed to the callback. It is null because there is nothing to pass this time. The third parameter is the amount of time to delay before the callback parameter invokes its methods. I use System.Threading.Timeout helper class to represent infinite timeout which simply means the timer is not going to start at the moment. And the final fourth parameter represents the time interval between invocations of the methods referenced by callback. Infinite timeout timespan means the callback method will be executed just once. Well, the timer has been created. Let’s take a look how you can start the timer.   1: private void StartTimer(object sender, RoutedEventArgs e) 2: { 3: timer.Change(TimeSpan.Zero, new TimeSpan(0, 0, 1)); 4:   5: // Disable the start buttons and enable the reset button. 6: }   The timer is started by calling its Change method. It accepts two arguments: the amount of time to delay before the invoking the callback method and the time interval between invocations of the callback. TimeSpan.Zero means we start the timer immediately and TimeSpan(0, 0, 1) tells the timer to tick every second. There is one method hasn’t been shown yet. This is the callback method OnTimer which does a simple task: it shows current time in the center of the screen. Unfortunately you cannot simple write something like this:   1: clock.Content = DateTime.Now.ToString("hh:mm:ss");   The reason is Timer runs callback method on a separate thread, and it is not possible to access GUI controls from a non-GUI thread. You can avoid the problem using System.Windows.Threading.Dispatcher class.   1: private void OnTimer(object state) 2: { 3: Dispatcher.Invoke(() => ShowTime()); 4: } 5:   6: private void ShowTime() 7: { 8: clock.Content = DateTime.Now.ToString("hh:mm:ss"); 9: }   You can build similar application using System.Windows.Threading.DispatcherTimer class. The class represents a timer which is integrated into the Dispatcher queue. It means that your callback method is executed on GUI thread and you can write a code which updates your GUI components directly.   1: private DispatcherTimer dispatcherTimer; 2:   3: public MainWindow() 4: { 5: // Form initialization code 6:   7: dispatcherTimer = new DispatcherTimer { Interval = new TimeSpan(0, 0, 1) }; 8: dispatcherTimer.Tick += OnDispatcherTimer; 9: } Dispatcher timer has nicer and cleaner API. All you need is to specify tick interval and Tick event handler. The you just call Start method to start the timer.   private void StartDispatcher(object sender, RoutedEventArgs e) { dispatcherTimer.Start(); // Disable the start buttons and enable the reset button. } And, since the Tick event handler is executed on GUI thread, the code which sets the actual time is straightforward.   1: private void OnDispatcherTimer(object sender, EventArgs e) 2: { 3: ShowTime(); 4: } We’re almost done. Let’s take a look how to stop the timers. It is easy with the Dispatcher Timer.   1: dispatcherTimer.Stop(); And slightly more complicated with the Timer. You should use Change method again.   1: timer.Change(Timeout.InfiniteTimeSpan, Timeout.InfiniteTimeSpan); What is the best way to add timer into an application? The Dispatcher Timer has simple interface, but its advantages are disadvantages at the same time. You should not use it if your Tick event handler executes time-consuming operations. It freezes your window which it is executing the event handler method. You should think about using System.Threading.Timer in this case. The code is available on GitHub.

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• About Me

  - by Jeffrey West

  I’m new to blogging.  This is the second blog post that I have written, and before I go too much further I wanted the readers of my blog to know a bit more about me… Kid’s Stuff By trade, I am a programmer (or coder, developer, engineer, architect, etc).  I started programming when I was 12 years old.  When I was 7, we got our first ‘family’ computer – an Apple IIc.  It was great to play games on, and of course what else was a 7-year-old going to do with it.  I did have one problem with it, though.  When I put in my 5.25” floppy to play a game, sometimes, instead loading my game I would get a mysterious ‘]’ on the screen with a flashing cursor.  This, of course, was not my game.  Much like the standard ‘Microsoft fix’ is to reboot, back then you would take the floppy out, shake it, and restart the computer and pray for a different result. One day, I learned at school that I could topple my nemesis – the ‘]’ and flashing cursor – by typing ‘load’ and pressing enter.  Most of the time, this would load my game and then I would get to play.  Problem solved.  However, I began to wonder – what else can I make it do? When I was in 5th grade my dad got a bright idea to buy me a Tandy 1000HX.  He didn’t know what I was going to do with it, and neither did I.  Least of all, my mom wasn’t happy about buying a 5th grader a $1,000 computer.  Nonetheless, Over time, I learned how to write simple basic programs out of the back of my Math book: 10 x=5 20 y=6 30 PRINT x+y That was fun for all of about 5 minutes.  I needed more – more challenges, more things that I could make the computer do.  In order to quench this thirst my parents sent me to National Computer Camps in Connecticut.  It was one of the best experiences of my childhood, and I spent 3 weeks each summer after that learning BASIC, Pascal, Turbo C and some C++.  There weren’t many kids at the time who knew anything about computers, and lets just say my knowledge of and interest in computers didn’t score me many ‘cool’ points.  My experiences at NCC set me on the path that I find myself on now, and I am very thankful for the experience.  Real Life I have held various positions in the past at different levels within the IT layer cake.  I started out as a Software Developer for a startup in the Dallas, TX area building software for semiconductor testing statistical process control and sampling.  I was the second Java developer that was hired, and the ninth employee overall, so I got a great deal of experience developing software.  Since there weren’t that many people in the organization, I also got a lot of field experience which meant that if I screwed up the code, I got yelled at (figuratively) by both my boss AND the customer.  Fun Times!  What made it better was that I got to help run pilot programs in Taiwan, Singapore, Malaysia and Malta.  Getting yelled at in Taiwan is slightly less annoying that getting yelled at in Dallas… I spent the next 5 years at Accenture doing systems integration in the ‘SOA’ group.  I joined as a Consultant and left as a Senior Manager.  I started out writing code in WebLogic Integration and left after I wrapped up project where I led a team of 25 to develop the next generation of a digital media platform to deliver HD content in a digital format.  At Accenture, I had the pleasure of working with some truly amazing people – mentoring some and learning from many others – and on some incredible real-world IT projects.  Given my background with the BEA stack of products I was often called in to troubleshoot and tune WebLogic, ALBPM and ALSB installations and have logged many hours digging through thread dumps, running performance tests with SoapUI and decompiling Java classes we didn’t have the source for so I could see what was going on in the code. I am now a Senior Principal Product Manager at Oracle in the Application Grid practice.  The term ‘Application Grid’ refers to a collection of software and hardware products within Oracle that enables customers to build horizontally scalable systems.  This collection of products includes WebLogic, GlassFish, Coherence, Tuxedo and the JRockit/HotSpot JVMs (HotSprocket, maybe?).  Now, with the introduction of Exalogic it has grown to include hardware as well. Wrapping it up… I love technology and have a diverse background ranging from software development to HW and network architecture & tuning.  I have held certifications for being an Oracle Certified DBA, MSCE and Cisco Certified Network Professional (CCNP), among others and I have put those to great use over my career.  I am excited about programming & technology and I enjoy helping people learn and be successful.  If you are having challenges with WebLogic, BPM or Service Bus feel free to reach out to me and I’ll be happy to help as I have time. Thanks for stopping by!   --Jeff

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• WIF, ADFS 2 and WCF&ndash;Part 6: Chaining multiple Token Services

  - by Your DisplayName here!

  See the previous posts first. So far we looked at the (simpler) scenario where a client acquires a token from an identity provider and uses that for authentication against a relying party WCF service. Another common scenario is, that the client first requests a token from an identity provider, and then uses this token to request a new token from a Resource STS or a partner’s federation gateway. This sounds complicated, but is actually very easy to achieve using WIF’s WS-Trust client support. The sequence is like this: Request a token from an identity provider. You use some “bootstrap” credential for that like Windows integrated, UserName or a client certificate. The realm used for this request is the identifier of the Resource STS/federation gateway. Use the resulting token to request a new token from the Resource STS/federation gateway. The realm for this request would be the ultimate service you want to talk to. Use this resulting token to authenticate against the ultimate service. Step 1 is very much the same as the code I have shown in the last post. In the following snippet, I use a client certificate to get a token from my STS: private static SecurityToken GetIdPToken() {     var factory = new WSTrustChannelFactory(         new CertificateWSTrustBinding(SecurityMode.TransportWithMessageCredential,         idpEndpoint);     factory.TrustVersion = TrustVersion.WSTrust13;       factory.Credentials.ClientCertificate.SetCertificate(         StoreLocation.CurrentUser,         StoreName.My,         X509FindType.FindBySubjectDistinguishedName,         "CN=Client");       var rst = new RequestSecurityToken     {         RequestType = RequestTypes.Issue,         AppliesTo = new EndpointAddress(rstsRealm),         KeyType = KeyTypes.Symmetric     };       var channel = factory.CreateChannel();     return channel.Issue(rst); } To use a token to request another token is slightly different. First the IssuedTokenWSTrustBinding is used and second the channel factory extension methods are used to send the identity provider token to the Resource STS: private static SecurityToken GetRSTSToken(SecurityToken idpToken) {     var binding = new IssuedTokenWSTrustBinding();     binding.SecurityMode = SecurityMode.TransportWithMessageCredential;       var factory = new WSTrustChannelFactory(         binding,         rstsEndpoint);     factory.TrustVersion = TrustVersion.WSTrust13;     factory.Credentials.SupportInteractive = false;       var rst = new RequestSecurityToken     {         RequestType = RequestTypes.Issue,         AppliesTo = new EndpointAddress(svcRealm),         KeyType = KeyTypes.Symmetric     };       factory.ConfigureChannelFactory();     var channel = factory.CreateChannelWithIssuedToken(idpToken);     return channel.Issue(rst); } For this particular case I chose an ADFS endpoint for issued token authentication (see part 1 for more background). Calling the service now works exactly like I described in my last post. You may now wonder if the same thing can be also achieved using configuration only – absolutely. But there are some gotchas. First of all the configuration files becomes quite complex. As we discussed in part 4, the bindings must be nested for WCF to unwind the token call-stack. But in this case svcutil cannot resolve the first hop since it cannot use metadata to inspect the identity provider. This binding must be supplied manually. The other issue is around the value for the realm/appliesTo when requesting a token for the R-STS. Using the manual approach you have full control over that parameter and you can simply use the R-STS issuer URI. Using the configuration approach, the exact address of the R-STS endpoint will be used. This means that you may have to register multiple R-STS endpoints in the identity provider. Another issue you will run into is, that ADFS does only accepts its configured issuer URI as a known realm by default. You’d have to manually add more audience URIs for the specific endpoints using the ADFS Powershell commandlets. I prefer the “manual” approach. That’s it. Hope this is useful information.

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• Explaining Explain Plan Notes for Auto DOP

  - by jean-pierre.dijcks

  I've recently gotten some questions around "why do I not see a parallel plan" while Auto DOP is on (I think)...? It is probably worthwhile to quickly go over some of the ways to find out what Auto DOP was thinking. In general, there is no need to go tracing sessions and look under the hood. The thing to start with is to do an explain plan on your statement and to look at the parameter settings on the system. Parameter Settings to Look At First and foremost, make sure that parallel_degree_policy = AUTO. If you have that parameter set to LIMITED you will not have queuing and we will only do the auto magic if your objects are set to default parallel (so no degree specified). Next you want to look at the value of parallel_degree_limit. It is typically set to CPU, which in default settings equates to the Default DOP of the system. If you are testing Auto DOP itself and the impact it has on performance you may want to leave it at this CPU setting. If you are running concurrent statements you may want to give this some more thoughts. See here for more information. In general, do stick with either CPU or with a specific number. For now avoid the IO setting as I've seen some mixed results with that... In 11.2.0.2 you should also check that IO Calibrate has been run. Best to simply do a: SQL> select * from V$IO_CALIBRATION_STATUS; STATUS        CALIBRATION_TIME ------------- ---------------------------------------------------------------- READY         04-JAN-11 10.04.13.104 AM You should see that your IO Calibrate is READY and therefore Auto DOP is ready. In any case, if you did not run the IO Calibrate step you will get the following note in the explain plan: Note -----    - automatic DOP: skipped because of IO calibrate statistics are missing One more note on calibrate_io, if you do not have asynchronous IO enabled you will see:  ERROR at line 1: ORA-56708: Could not find any datafiles with asynchronous i/o capability ORA-06512: at "SYS.DBMS_RMIN", line 463 ORA-06512: at "SYS.DBMS_RESOURCE_MANAGER", line 1296 ORA-06512: at line 7 While this is changed in some fixes to the calibrate procedure, you should really consider switching asynchronous IO on for your data warehouse. Explain Plan Explanation To see the notes that are shown and explained here (and the above little snippet ) you can use a simple explain plan mechanism. There should  be no need to add +parallel etc. explain plan for <statement> SELECT PLAN_TABLE_OUTPUT FROM TABLE(DBMS_XPLAN.DISPLAY()); Auto DOP The note structure displaying why Auto DOP did not work (with the exception noted above on IO Calibrate) is like this: Automatic degree of parallelism is disabled: <reason> These are the reason codes: Parameter -  parallel_degree_policy = manual which will not allow Auto DOP to kick in  Hint - One of the following hints are used NOPARALLEL, PARALLEL(1), PARALLEL(MANUAL) Outline - A SQL outline of an older version (before 11.2) is used SQL property restriction - The statement type does not allow for parallel processing Rule-based mode - Instead of the Cost Based Optimizer the system is using the RBO Recursive SQL statement - The statement type does not allow for parallel processing pq disabled/pdml disabled/pddl disabled - For some reason (alter session?) parallelism is disabled Limited mode but no parallel objects referenced - your parallel_degree_policy = LIMITED and no objects in the statement are decorated with the default PARALLEL degree. In most cases all objects have a specific degree in which case Auto DOP will honor that degree. Parallel Degree Limited When Auto DOP does it works you may see the cap you imposed with parallel_degree_limit showing up in the note section of the explain plan: Note -----    - automatic DOP: Computed Degree of Parallelism is 16 because of degree limit This is an obvious indication that your are being capped for this statement. There is one quite interesting one that happens when you are being capped at DOP = 1. First of you get a serial plan and the note changes slightly in that it does not indicate it is being capped (we hope to update the note at some point in time to be more specific). It right now looks like this: Note -----    - automatic DOP: Computed Degree of Parallelism is 1 Dynamic Sampling With 11.2.0.2 you will start seeing another interesting change in parallel plans, and since we are talking about the note section here, I figured we throw this in for good measure. If we deem the parallel (!) statement complex enough, we will enact dynamic sampling on your query. This happens as long as you did not change the default for dynamic sampling on the system. The note looks like this: Note ----- - dynamic sampling used for this statement (level=5)

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• Extreme Optimization – Numerical Algorithm Support

  - by JoshReuben

  Function Delegates Many calculations involve the repeated evaluation of one or more user-supplied functions eg Numerical integration. The EO MathLib provides delegate types for common function signatures and the FunctionFactory class can generate new delegates from existing ones. RealFunction delegate - takes one Double parameter – can encapsulate most of the static methods of the System.Math class, as well as the classes in the Extreme.Mathematics.SpecialFunctions namespace: var sin = new RealFunction(Math.Sin); var result = sin(1); BivariateRealFunction delegate - takes two Double parameters: var atan2 = new BivariateRealFunction (Math.Atan2); var result = atan2(1, 2); TrivariateRealFunction delegate – represents a function takes three Double arguments ParameterizedRealFunction delegate - represents a function taking one Integer and one Double argument that returns a real number. The Pow method implements such a function, but the arguments need order re-arrangement: static double Power(int exponent, double x) { return ElementaryFunctions.Pow(x, exponent); } ... var power = new ParameterizedRealFunction(Power); var result = power(6, 3.2); A ComplexFunction delegate - represents a function that takes an Extreme.Mathematics.DoubleComplex argument and also returns a complex number. MultivariateRealFunction delegate - represents a function that takes an Extreme.Mathematics.LinearAlgebra.Vector argument and returns a real number. MultivariateVectorFunction delegate - represents a function that takes a Vector argument and returns a Vector. FastMultivariateVectorFunction delegate - represents a function that takes an input Vector argument and an output Matrix argument – avoiding object construction  The FunctionFactory class RealFromBivariateRealFunction and RealFromParameterizedRealFunction helper methods - transform BivariateRealFunction or a ParameterizedRealFunction into a RealFunction delegate by fixing one of the arguments, and treating this as a new function of a single argument. var tenthPower = FunctionFactory.RealFromParameterizedRealFunction(power, 10); var result = tenthPower(x); Note: There is no direct way to do this programmatically in C# - in F# you have partial value functions where you supply a subset of the arguments (as a travelling closure) that the function expects. When you omit arguments, F# generates a new function that holds onto/remembers the arguments you passed in and "waits" for the other parameters to be supplied. let sumVals x y = x + y     let sumX = sumVals 10     // Note: no 2nd param supplied.     // sumX is a new function generated from partially applied sumVals.     // ie "sumX is a partial application of sumVals." let sum = sumX 20     // Invokes sumX, passing in expected int (parameter y from original)  val sumVals : int -> int -> int val sumX : (int -> int) val sum : int = 30 RealFunctionsToVectorFunction and RealFunctionsToFastVectorFunction helper methods - combines an array of delegates returning a real number or a vector into vector or matrix functions. The resulting vector function returns a vector whose components are the function values of the delegates in the array. var funcVector = FunctionFactory.RealFunctionsToVectorFunction(     new MultivariateRealFunction(myFunc1),     new MultivariateRealFunction(myFunc2));  The IterativeAlgorithm<T> abstract base class Iterative algorithms are common in numerical computing - a method is executed repeatedly until a certain condition is reached, approximating the result of a calculation with increasing accuracy until a certain threshold is reached. If the desired accuracy is achieved, the algorithm is said to converge. This base class is derived by many classes in the Extreme.Mathematics.EquationSolvers and Extreme.Mathematics.Optimization namespaces, as well as the ManagedIterativeAlgorithm class which contains a driver method that manages the iteration process.  The ConvergenceTest abstract base class This class is used to specify algorithm Termination , convergence and results - calculates an estimate for the error, and signals termination of the algorithm when the error is below a specified tolerance. Termination Criteria - specify the success condition as the difference between some quantity and its actual value is within a certain tolerance – 2 ways: absolute error - difference between the result and the actual value. relative error is the difference between the result and the actual value relative to the size of the result. Tolerance property - specify trade-off between accuracy and execution time. The lower the tolerance, the longer it will take for the algorithm to obtain a result within that tolerance. Most algorithms in the EO NumLib have a default value of MachineConstants.SqrtEpsilon - gives slightly less than 8 digits of accuracy. ConvergenceCriterion property - specify under what condition the algorithm is assumed to converge. Using the ConvergenceCriterion enum: WithinAbsoluteTolerance / WithinRelativeTolerance / WithinAnyTolerance / NumberOfIterations Active property - selectively ignore certain convergence tests Error property - returns the estimated error after a run MaxIterations / MaxEvaluations properties - Other Termination Criteria - If the algorithm cannot achieve the desired accuracy, the algorithm still has to end – according to an absolute boundary. Status property - indicates how the algorithm terminated - the AlgorithmStatus enum values:NoResult / Busy / Converged (ended normally - The desired accuracy has been achieved) / IterationLimitExceeded / EvaluationLimitExceeded / RoundOffError / BadFunction / Divergent / ConvergedToFalseSolution. After the iteration terminates, the Status should be inspected to verify that the algorithm terminated normally. Alternatively, you can set the ThrowExceptionOnFailure to true. Result property - returns the result of the algorithm. This property contains the best available estimate, even if the desired accuracy was not obtained. IterationsNeeded / EvaluationsNeeded properties - returns the number of iterations required to obtain the result, number of function evaluations.  Concrete Types of Convergence Test classes SimpleConvergenceTest class - test if a value is close to zero or very small compared to another value. VectorConvergenceTest class - test convergence of vectors. This class has two additional properties. The Norm property specifies which norm is to be used when calculating the size of the vector - the VectorConvergenceNorm enum values: EuclidianNorm / Maximum / SumOfAbsoluteValues. The ErrorMeasure property specifies how the error is to be measured – VectorConvergenceErrorMeasure enum values: Norm / Componentwise ConvergenceTestCollection class - represent a combination of tests. The Quantifier property is a ConvergenceTestQuantifier enum that specifies how the tests in the collection are to be combined: Any / All  The AlgorithmHelper Class inherits from IterativeAlgorithm<T> and exposes two methods for convergence testing. IsValueWithinTolerance<T> method - determines whether a value is close to another value to within an algorithm's requested tolerance. IsIntervalWithinTolerance<T> method - determines whether an interval is within an algorithm's requested tolerance.

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• 2D Selective Gaussian Blur

  - by Joshua Thomas

  I am attempting to use Gaussian blur on a 2D platform game, selectively blurring specific types of platforms with different amounts. I am currently just messing around with simple test code, trying to get it to work correctly. What I need to eventually do is create three separate render targets, leave one normal, blur one slightly, and blur the last heavily, then recombine on the screen. Where I am now is I have successfully drawn into a new render target and performed the gaussian blur on it, but when I draw it back to the screen everything is purple aside from the platforms I drew to the target. This is my .fx file: #define RADIUS 7 #define KERNEL_SIZE (RADIUS * 2 + 1) //----------------------------------------------------------------------------- // Globals. //----------------------------------------------------------------------------- float weights[KERNEL_SIZE]; float2 offsets[KERNEL_SIZE]; //----------------------------------------------------------------------------- // Textures. //----------------------------------------------------------------------------- texture colorMapTexture; sampler2D colorMap = sampler_state { Texture = <colorMapTexture>; MipFilter = Linear; MinFilter = Linear; MagFilter = Linear; }; //----------------------------------------------------------------------------- // Pixel Shaders. //----------------------------------------------------------------------------- float4 PS_GaussianBlur(float2 texCoord : TEXCOORD) : COLOR0 { float4 color = float4(0.0f, 0.0f, 0.0f, 0.0f); for (int i = 0; i < KERNEL_SIZE; ++i) color += tex2D(colorMap, texCoord + offsets[i]) * weights[i]; return color; } //----------------------------------------------------------------------------- // Techniques. //----------------------------------------------------------------------------- technique GaussianBlur { pass { PixelShader = compile ps_2_0 PS_GaussianBlur(); } } This is the code I'm using for the gaussian blur: public Texture2D PerformGaussianBlur(Texture2D srcTexture, RenderTarget2D renderTarget1, RenderTarget2D renderTarget2, SpriteBatch spriteBatch) { if (effect == null) throw new InvalidOperationException("GaussianBlur.fx effect not loaded."); Texture2D outputTexture = null; Rectangle srcRect = new Rectangle(0, 0, srcTexture.Width, srcTexture.Height); Rectangle destRect1 = new Rectangle(0, 0, renderTarget1.Width, renderTarget1.Height); Rectangle destRect2 = new Rectangle(0, 0, renderTarget2.Width, renderTarget2.Height); // Perform horizontal Gaussian blur. game.GraphicsDevice.SetRenderTarget(renderTarget1); effect.CurrentTechnique = effect.Techniques["GaussianBlur"]; effect.Parameters["weights"].SetValue(kernel); effect.Parameters["colorMapTexture"].SetValue(srcTexture); effect.Parameters["offsets"].SetValue(offsetsHoriz); spriteBatch.Begin(0, BlendState.Opaque, null, null, null, effect); spriteBatch.Draw(srcTexture, destRect1, Color.White); spriteBatch.End(); // Perform vertical Gaussian blur. game.GraphicsDevice.SetRenderTarget(renderTarget2); outputTexture = (Texture2D)renderTarget1; effect.Parameters["colorMapTexture"].SetValue(outputTexture); effect.Parameters["offsets"].SetValue(offsetsVert); spriteBatch.Begin(0, BlendState.Opaque, null, null, null, effect); spriteBatch.Draw(outputTexture, destRect2, Color.White); spriteBatch.End(); // Return the Gaussian blurred texture. game.GraphicsDevice.SetRenderTarget(null); outputTexture = (Texture2D)renderTarget2; return outputTexture; } And this is the draw method affected: public void Draw(SpriteBatch spriteBatch) { device.SetRenderTarget(maxBlur); spriteBatch.Begin(); foreach (Brick brick in blueBricks) brick.Draw(spriteBatch); spriteBatch.End(); blue = gBlur.PerformGaussianBlur((Texture2D) maxBlur, helperTarget, maxBlur, spriteBatch); spriteBatch.Begin(); device.SetRenderTarget(null); foreach (Brick brick in redBricks) brick.Draw(spriteBatch); foreach (Brick brick in greenBricks) brick.Draw(spriteBatch); spriteBatch.Draw(blue, new Rectangle(0, 0, blue.Width, blue.Height), Color.White); foreach (Brick brick in purpleBricks) brick.Draw(spriteBatch); spriteBatch.End(); } I'm sorry about the massive brick of text and images(or not....new user, I tried, it said no), but I wanted to get my problem across clearly as I have been searching for an answer to this for quite a while now. As a side note, I have seen the bloom sample. Very well commented, but overly complicated since it deals in 3D; I was unable to take what I needed to learn form it. Thanks for any and all help.

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• JDK bug migration: components and subcomponents

  - by darcy

  One subtask of the JDK migration from the legacy bug tracking system to JIRA was reclassifying bugs from a three-level taxonomy in the legacy system, (product, category, subcategory), to a fundamentally two-level scheme in our customized JIRA instance, (component, subcomponent). In the JDK JIRA system, there is technically a third project-level classification, but by design a large majority of JDK-related bugs were migrated into a single "JDK" project. In the end, over 450 legacy subcategories were simplified into about 120 subcomponents in JIRA. The 120 subcomponents are distributed among 17 components. A rule of thumb used was that a subcategory had to have at least 50 bugs in it for it to be retained. Below is a listing the component / subcomponent classification of the JDK JIRA project along with some notes and guidance on which OpenJDK email addresses cover different areas. Eventually, a separate incidents project to host new issues filed at bugs.sun.com will use a slightly simplified version of this scheme. The preponderance of bugs and subcomponents for the JDK are in library-related areas, with components named foo-libs and subcomponents primarily named after packages. While there was an overall condensation of subcomponents in the migration, in some cases long-standing informal divisions in core libraries based on naming conventions in the description were promoted to formal subcomponents. For example, hundreds of bugs in the java.util subcomponent whose descriptions started with "(coll)" were moved into java.util:collections. Likewise, java.lang bugs starting with "(reflect)" and "(proxy)" were moved into java.lang:reflect. client-libs (Predominantly discussed on 2d-dev and awt-dev and swing-dev.) 2d demo java.awt java.awt:i18n java.beans (See beans-dev.) javax.accessibility javax.imageio javax.sound (See sound-dev.) javax.swing core-libs (See core-libs-dev.) java.io java.io:serialization java.lang java.lang.invoke java.lang:class_loading java.lang:reflect java.math java.net java.nio (Discussed on nio-dev.) java.nio.charsets java.rmi java.sql java.sql:bridge java.text java.util java.util.concurrent java.util.jar java.util.logging java.util.regex java.util:collections java.util:i18n javax.annotation.processing javax.lang.model javax.naming (JNDI) javax.script javax.script:javascript javax.sql org.openjdk.jigsaw (See jigsaw-dev.) security-libs (See security-dev.) java.security javax.crypto (JCE: includes SunJCE/MSCAPI/UCRYPTO/ECC) javax.crypto:pkcs11 (JCE: PKCS11 only) javax.net.ssl (JSSE, includes javax.security.cert) javax.security javax.smartcardio javax.xml.crypto org.ietf.jgss org.ietf.jgss:krb5 other-libs corba corba:idl corba:orb corba:rmi-iiop javadb other (When no other subcomponent is more appropriate; use judiciously.) Most of the subcomponents in the xml component are related to jaxp. xml jax-ws jaxb javax.xml.parsers (JAXP) javax.xml.stream (JAXP) javax.xml.transform (JAXP) javax.xml.validation (JAXP) javax.xml.xpath (JAXP) jaxp (JAXP) org.w3c.dom (JAXP) org.xml.sax (JAXP) For OpenJDK, most JVM-related bugs are connected to the HotSpot Java virtual machine. hotspot (See hotspot-dev.) build compiler (See hotspot-compiler-dev.) gc (garbage collection, see hotspot-gc-dev.) jfr (Java Flight Recorder) jni (Java Native Interface) jvmti (JVM Tool Interface) mvm (Multi-Tasking Virtual Machine) runtime (See hotspot-runtime-dev.) svc (Servicability) test core-svc (See serviceability-dev.) debugger java.lang.instrument java.lang.management javax.management tools The full JDK bug database contains entries related to legacy virtual machines that predate HotSpot as well as retired APIs. vm-legacy jit (Sun Exact VM) jit_symantec (Symantec VM, before Exact VM) jvmdi (JVM Debug Interface ) jvmpi (JVM Profiler Interface ) runtime (Exact VM Runtime) Notable command line tools in the $JDK/bin directory have corresponding subcomponents. tools appletviewer apt (See compiler-dev.) hprof jar javac (See compiler-dev.) javadoc(tool) (See compiler-dev.) javah (See compiler-dev.) javap (See compiler-dev.) jconsole launcher updaters (Timezone updaters, etc.) visualvm Some aspects of JDK infrastructure directly affect JDK Hg repositories, but other do not. infrastructure build (See build-dev and build-infra-dev.) licensing (Covers updates to the third party readme, licenses, and similar files.) release_eng (Release engineering) staging (Staging of web pages related to JDK releases.) The specification subcomponent encompasses the formal language and virtual machine specifications. specification language (The Java Language Specification) vm (The Java Virtual Machine Specification) The code for the deploy and install areas is not currently included in OpenJDK. deploy deployment_toolkit plugin webstart install auto_update install servicetags In the JDK, there are a number of cross-cutting concerns whose organization is essentially orthogonal to other areas. Since these areas generally have dedicated teams working on them, it is easier to find bugs of interest if these bugs are grouped first by their cross-cutting component rather than by the affected technology. docs doclet guides hotspot release_notes tools tutorial embedded build hotspot libraries globalization locale-data translation performance hotspot libraries The list of subcomponents will no doubt grow over time, but my inclination is to resist that growth since the addition of each subcomponent makes the system as a whole more complicated and harder to use. When the system gets closer to being externalized, I plan to post more blog entries describing recommended use of various custom fields in the JDK project.

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• Cowboy Agile?

  - by Robert May

  In a previous post, I outlined the rules of Scrum.  This post details one of those rules. I’ve often heard similar phrases around Scrum that clue me in to someone who doesn’t understand Scrum.  The phrases go something like this: “We don’t do Agile because the idea of letting people just do whatever they want is wrong.  We believe in a more structured approach.” (i.e. Work is Prison, and I’m the Warden!) “I love Agile.  Agile lets us do whatever we want!” (Cowboy Agile?) “We’re Agile, but we use a process that I’ve created.” (Cowboy Agile?) All of those phrases have one thing in common:  The assumption that Agile, and I mean Scrum, lets you do whatever you want.  This is simply not true. Executing Scrum properly requires more dedication, rigor, and diligence than happens in most traditional development methods. Scrum and Waterfall Compared Since Scrum and Waterfall are two of the most commonly used methodologies, a little bit of contrasting and comparing is in order. Waterfall Scrum A project manager defines all tasks and then manages the tasks that team members are working on. The team members define the tasks and estimates of the stories for the current iteration.  Any team member may work on any task in the iteration. Usually only a few milestones that need to be met, the milestones are measured in months, and these milestones are expected to be missed.  Little work is ever done to improve estimates and poor estimators can hide behind high estimates. Stories must be delivered every iteration, milestones are measured in hours, and the team is expected to figure out why their estimates were wrong, even when they were under.  Repeated misses can get the entire team fired. Partially completed work is normal. Partially completed work doesn’t count. Nobody knows the task you’re working on. Everyone knows what you’re working on, whether or not you’re making progress and how much longer you think its going to take, in hours. Little requirement to show working code.  Prototypes are ok. Working code must be shown each iteration.  No smoke and mirrors allowed.  Testing is done in lengthy cycles at the end of development.  Developers aren’t held accountable. Testing is part of the team.  If the testers don’t accept the story as complete, the team can’t count it.  Complete means that the story’s functionality works as designed.  The team can’t have any open defects on the story. Velocity is rarely truly measured and difficult to evaluate. Velocity is integral to the process and can be seen at a glance and everyone in the company knows what it is. A business analyst writes requirements.  Designers mock up screens.  Developers hide behind “I did it just like the spec doc told me to and made the screen exactly like the picture” Developers are expected to collaborate in real time.  If a design is bad or lacks needed details, the developers are required to get it right in the iteration, because all software must be functional.  Designers and Business Analysts are part of the team and must do their work in iterations slightly ahead of the developers. Upper Management is often surprised.  “You told me things were going well two months ago!” Management receives updates at the end of every iteration showing them exactly what the team did and how that compares to what' is remaining in the backlog.  Managers know every iteration what their money is buying. Status meetings are rare or don’t occur.  Email is a primary form of communication. Teams coordinate every single day with each other and use other high bandwidth communication channels to make sure they’re making progress.  Email is used only as a last resort.  Instead, team members stand up, walk to each other, and talk, face to face.  If that’s not possible, they pick up the phone. IF someone asks what happened, its at the end of a lengthy development cycle measured in months, and nobody really knows why it happened. Someone asks what happened every iteration.  The team talks about what happened, and then adapts to make sure that what happened either never happens again or happens every time.   That’s probably enough for now.  As you can see, a lot is required of Scrum teams! One of the key differences in Scrum is that the burden for many activities is shifted to a group of people who share responsibility, instead of a single person having responsibility.  This is a very good thing, since small groups usually come up with better and more insightful work than single individuals.  This shift also results in better velocity.  Team members can take vacations and the rest of the team simply picks up the slack.  With Waterfall, if a key team member takes a vacation, delays can ensue. Scrum requires much more out of every team member and as a result, Scrum teams outperform non-Scrum teams working 60 hour weeks. Recommended Reading Everyone considering Scrum should read Mike Cohn’s excellent book, User Stories Applied. Technorati Tags: Agile,Scrum,Waterfall

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• Simple Scripting for your Exalogic Storage

  - by Trond Strømme

  As part of my job in Oracle ACS (Advanced Customer Services) I'm handling lots of different systems and customers. Among the recent systems I worked with have been Oracle's Exalogic engineered systems. One of the things I'd never had much exposure to as a system developer/architect/middleware guy/Java dude has been storage; outside of consuming it for my photography needs.. Well, I'm always ready for a new challenge... I'd downloaded the 7000 series storage simulator when it was released in the good old Sun days, found it fun and instructive to play around with, but as I never touched storage in any way (besides consuming it..) I forgot about it. A couple of years ago when I started working with Exalogic engineered systems it again came into light as an invaluable learning and testing tool for the embedded storage in an Exalogic;  Oracle's Sun ZFS Storage 7320 Appliance.  aaaanyway... I've been "booted" into a part-time role as the interim storage/system admin/middleware/Java guy for a client and found I needed to create the occasional report or summary or whatever.. of what's using the storage in the 7320 (as default configured for an Exalogic, 40T of disk in a mirrored configuration, yielding 18T of actual space.) Reading the nice documentation and some articles on the Oracle Technology Network I saw great possibilities with the embedded ECMAScript3/JavaScript engine in the 7000 series.  In my personal opinion anyone who's dealing with Exalogic administration, or exposed to any of the 7000 series of storage appliances and servers that Oracle offers should have a VirtualBox instance of it kicking around. For development and testing it's a fantastic tool. (It can save you from explaining (most) of the embarrassing FAILS you can do if you test something in a production system to your management...) So download, and install.  A small sidestep, if after firing up the 7000 series simulator in VirtualBox you've forgotten what it's IP address is, the following will sort you out if you log in directly via the running VirtualBox VM. So in my case I can ssh to 192.168.56.101 or point a browser to https://192.168.56.101:215 to log into the storage appliance. One simple way of executing a script on the 7320 is to ssh to the device and redirecting a file with the script in it to ssh. ssh [email protected] < myscript.js One question I got from my client and the people who will take over the systems was: "how can we see the quotas and allocations for all projects/shares in one easy go so we don't have to go navigating around in the BUI for all the hundreds of shares the 7320 is hosting just to check if anything is running dry?" Easy! JavaScript time, VirtualBox and emacs! //NOTE! this script is available 'as is' It has ben run on a couple of 7320's, (running 2010.08.17.3.0,1-1.25 & // 2011.04.24.1.0,1-1.8) a 7420 and the VB image, but I personally //offer no guarantee whatsoever that it won't make your server topple, catch fire or in any way go pear shaped.. //run at your own risk or learn from my code and or mistakes.. script run('cd /'); run('shares'); //get all projects: proj = list(); function spaceToGig(bytes){ return bytes/1073741824; //convert bytes to GB } function fullInPercent(quota, space_data){ tmp = (space_data/quota)*100; return tmp; } //print header, slightly good looking printf(" %s/%-15s %8s(GB) %7s(GB) %5s(GB) %7s(GB) %3s\n","Project", "Share","Quota","Ref", "Snap", "Total","%full"); printf("-------------------------------------------------------------------------------\n") //for each project, get all shares. check for quota and calculate percentage and human readable figures.. for (i=0;i<proj.length;i++){ run('select ' + proj[i]); //get all shares for a project var pshares = list(); //for each share get quota properties for (j=0;j<pshares.length;j++){ run('select ' + pshares[j]); quota = get('quota'); //properties associated with a share or inherited from a project spaceData = get('space_data'); spaceSnap = get('space_snapshots'); spaceTotal = get('space_total'); if(quota>0){ //has quota printf(" %s/%-15s \t%4.2fGB\t%.2fGB\t%.2fGB\t%.2fGB\t%5.2f%%\n",proj[i], pshares[j],spaceToGig(quota),spaceToGig(spaceData),spaceToGig(spaceSnap),spaceToGig(spaceTotal),fullInPercent(quota,spaceTotal)); }else{ //no quota printf(" %s/%-15s \t%8s\t%.2fGB\t%.2fGB\t%.2fGB\t%s\n",proj[i],pshares[j], "N/A", spaceToGig(spaceData),spaceToGig(spaceSnap),spaceToGig(spaceTotal),"N/A"); } run('cd ..'); } run('done'); } The resulting output should look something like this: Project/Share Quota(GB) Ref(GB) Snap(GB) Total(GB) %full ------------------------------------------------------------------------------- ACSExalogicSystem/domains N/A 0.04GB 0.00GB 0.04GB N/A ACSExalogicSystem/logs N/A 0.01GB 0.00GB 0.01GB N/A ACSExalogicSystem/nodemgrs N/A 0.00GB 0.00GB 0.00GB N/A ACSExalogicSystem/stores N/A 0.04GB 0.00GB 0.04GB N/A ***_dev/FMW_***_1 133GB 4.24GB 0.01GB 4.25GB 3.19% ***_dev/FMW_***_2 N/A 4.25GB 0.01GB 4.26GB N/A ***_dev/applications 10GB 0.00GB 0.00GB 0.00GB 0.00% ***_dev/domains 50GB 10.75GB 3.55GB 14.30GB 28.61% ***_dev/logs 20GB 0.32GB 0.01GB 0.33GB 1.66% ***_dev/softwaredepot 20GB 4.15GB 0.00GB 4.15GB 20.73% ***_dev/stores 20GB 0.01GB 0.00GB 0.01GB 0.05% ###_dev/FMW_###_1 400GB 17.63GB 0.12GB 17.75GB 4.44% ###_dev/applications N/A 0.00GB 0.00GB 0.00GB N/A ###_dev/domains 120GB 14.21GB 5.53GB 19.74GB 16.45% ###_dev/logs 15GB 0.00GB 0.00GB 0.00GB 0.00% ###_dev/softwaredepot 250GB 73.55GB 0.02GB 73.57GB 29.43% …snip My apologies if the output is a bit mis-aligned here and there, I only bothered making it look good, not perfect :/ I also removed some of the project names (*,#)

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• Professional Development – Difference Between Bio, CV and Resume

  - by Pinal Dave

  Applying for work can be very stressful – you want to put your best foot forward, and it can be very hard to sell yourself to a potential employer while highlighting your best characteristics and answering questions.  On top of that, some jobs require different application materials – a biography (or bio), a curriculum vitae (or CV), or a resume.  These things seem so interchangeable, so what is the difference? Let’s start with the one most of us have heard of – the resume.  A resume is a summary of your job and education history.  If you have ever applied for a job, you will have used a resume.  The ability to write a good resume that highlights your best characteristics and emphasizes your qualifications for a specific job is a skill that will take you a long way in the world.  For such an essential skill, unfortunately it is one that many people struggle with. RESUME So let’s discuss what makes a great resume.  First, make sure that your name and contact information are at the top, in large print (slightly larger font than the rest of the text, size 14 or 16 if the rest is size 12, for example).  You need to make sure that if you catch the recruiter’s attention and they know how to get a hold of you. As for qualifications, be quick and to the point.  Make your job title and the company the headline, and include your skills, accomplishments, and qualifications as bullet points.  Use good action verbs, like “finished,” “arranged,” “solved,” and “completed.”  Include hard numbers – don’t just say you “changed the filing system,” say that you “revolutionized the storage of over 250 files in less than five days.”  Doesn’t that sentence sound much more powerful? Curriculum Vitae (CV) Now let’s talk about curriculum vitae, or “CVs”.  A CV is more like an expanded resume.  The same rules are still true: put your name front and center, keep your contact info up to date, and summarize your skills with bullet points.  However, CVs are often required in more technical fields – like science, engineering, and computer science.  This means that you need to really highlight your education and technical skills. Difference between Resume and CV Resumes are expected to be one or two pages long – CVs can be as many pages as necessary.  If you are one of those people lucky enough to feel limited by the size constraint of resumes, a CV is for you!  On a CV you can expand on your projects, highlight really exciting accomplishments, and include more educational experience – including GPA and test scores from the GRE or MCAT (as applicable).  You can also include awards, associations, teaching and research experience, and certifications.  A CV is a place to really expand on all your experience and how great you will be in this particular position. Biography (Bio) Chances are, you already know what a bio is, and you have even read a few of them.  Think about the one or two paragraphs that every author includes in the back flap of a book.  Think about the sentences under a blogger’s photo on every “About Me” page.  That is a bio.  It is a way to quickly highlight your life experiences.  It is essentially the way you would introduce yourself at a party. Where a bio is required for a job, chances are they won’t want to know about where you were born and how many pets you have, though.  This is a way to summarize your entire job history in quick-to-read format – and sometimes during a job hunt, being able to get to the point and grab the recruiter’s interest is the best way to get your foot in the door.  Think of a bio as your entire resume put into words. Most bios have a standard format.  In paragraph one, talk about your most recent position and accomplishments there, specifically how they relate to the job you are applying for.  If you have teaching or research experience, training experience, certifications, or management experience, talk about them in paragraph two.  Paragraph three and four are for highlighting publications, education, certifications, associations, etc.  To wrap up your bio, provide your contact info and availability (dates and times). Where to use What? For most positions, you will know exactly what kind of application to use, because the job announcement will state what materials are needed – resume, CV, bio, cover letter, skill set, etc.  If there is any confusion, choose whatever the industry standard is (CV for technical fields, resume for everything else) or choose which of your documents is the strongest. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: About Me, PostADay, Professional Development, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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• Infiniband: a highperformance network fabric - Part I

  - by Karoly Vegh

  Introduction:At the OpenWorld this year I managed to chat with interesting people again - one of them answering Infiniband deepdive questions with ease by coffee turned out to be one of Oracle's IB engineers, Ted Kim, who actually actively participates in the Infiniband Trade Association and integrates Oracle solutions with this highspeed network. This is why I love attending OOW. He granted me an hour of his time to talk about IB. This post is mostly based on that tech interview.Start of the actual post: Traditionally datatransfer between servers and storage elements happens in networks with up to 10 gigabit/seconds or in SANs with up to 8 gbps fiberchannel connections. Happens. Well, data rather trickles through.But nowadays data amounts grow well over the TeraByte order of magnitude, and multisocket/multicore/multithread Servers hunger data that these transfer technologies just can't deliver fast enough, causing all CPUs of this world do one thing at the same speed - waiting for data. And once again, I/O is the bottleneck in computing. FC and Ethernet can't keep up. We have half-TB SSDs, dozens of TB RAM to store data to be modified in, but can't transfer it. Can't backup fast enough, can't replicate fast enough, can't synchronize fast enough, can't load fast enough. The bad news is, everyone is used to this, like back in the '80s everyone was used to start compile jobs and go for a coffee. Or on vacation. The good news is, there's an alternative. Not so-called "bleeding-edge" 8gbps, but (as of now) 56. Not layers of overhead, but low latency. And it is available now. It has been for a while, actually. Welcome to the world of Infiniband. Short history:Infiniband was born as a result of joint efforts of HPAQ, IBM, Intel, Sun and Microsoft. They planned to implement a next-generation I/O fabric, in the 90s. In the 2000s Infiniband (from now on: IB) was quite popular in the high-performance computing field, powering most of the top500 supercomputers. Then in the middle of the decade, Oracle realized its potential and used it as an interconnect backbone for the first Database Machine, the first Exadata. Since then, IB has been booming, Oracle utilizes and supports it in a large set of its HW products, it is the backbone of the famous Engineered Systems: Exadata, SPARC SuperCluster, Exalogic, OVCA and even the new DB backup/recovery box. You can also use it to make servers talk highspeed IP to eachother, or to a ZFS Storage Appliance. Following Oracle's lead, even IBM has jumped the wagon, and leverages IB in its PureFlex systems, their first InfiniBand Machines.IB Structural Overview: If you want to use IB in your servers, the first thing you will need is PCI cards, in IB terms Host Channel Adapters, or HCAs. Just like NICs for Ethernet, or HBAs for FC. In these you plug an IB cable, going to an IB switch providing connection to other IB HCAs. Of course you're going to need drivers for those in your OS. Yes, these are long-available for Solaris and Linux. Now, what protocols can you talk over IB? There's a range of choices. See, IB isn't accepting package loss like Ethernet does, and hence doesn't need to rely on TCP/IP as a workaround for resends. That is, you still can run IP over IB (IPoIB), and that is used in various cases for control functionality, but the datatransfer can run over more efficient protocols - like native IB. About PCI connectivity: IB cards, as you see are fast. They bring low latency, which is just as important as their bandwidth. Current IB cards run at 56 gbit/s. That is slightly more than double of the capacity of a PCI Gen2 slot (of ~25 gbit/s). And IB cards are equipped usually with two ports - that is, altogether you'd need 112 gbit/s PCI slots, to be able to utilize FDR IB cards in an active-active fashion. PCI Gen3 slots provide you with around ~50gbps. This is why the most IB cards are configured in an active-standby way if both ports are used. Once again the PCI slot is the bottleneck. Anyway, the new Oracle servers are equipped with Gen3 PCI slots, an the new IB HCAs support those too. Oracle utilizes the QDR HCAs, running at 40gbp/s brutto, which translates to a 32gbp/s net traffic due to the 10:8 signal-to-data information ratio. Consolidation techniques: Technology never stops to evolve. Mellanox is working on the 100 gbps (EDR) version already, which will be optical, since signal technology doesn't allow EDR to be copper. Also, I hear you say "100gbps? I will never use/need that much". Are you sure? Have you considered consolidation scenarios, where (for example with Oracle Virtual Network) you could consolidate your platform to a high densitiy virtualized solution providing many virtual 10gbps interfaces through that 100gbps? Technology never stops to evolve. I still remember when a 10mbps network was impressively fast. Back in those days, 16MB of RAM was a lot. Now we usually run servers with around 100.000 times more RAM. If network infrastrucure speends could grow as fast as main memory capacities, we'd have a different landscape now :) You can utilize SRIOV as well for consolidation. That is, if you run LDoms (aka Oracle VM Server for SPARC) you do not have to add physical IB cards to all your guest LDoms, and you do not need to run VIO devices through the hypervisor either (avoiding overhead). You can enable SRIOV on those IB cards, which practically virtualizes the PCI bus, and you can dedicate Physical- and Virtual Functions of the virtualized HCAs as native, physical HW devices to your guests. See Raghuram's excellent post explaining SRIOV. SRIOV for IB is supported since LDoms 3.1.  This post is getting lengthier, so I will rename it to Part I, and continue it in a second post. 

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• Easy Made Easier

  - by dragonfly

      How easy is it to deploy a 2 node, fully redundant Oracle RAC cluster? Not very. Unless you use an Oracle Database Appliance. The focus of this member of Oracle's Engineered Systems family is to simplify the configuration, management and maintenance throughout the life of the system, while offering pay-as-you-grow scaling. Getting a 2-node RAC cluster up and running in under 2 hours has been made possible by the Oracle Database Appliance. Don't take my word for it, just check out these blog posts from partners and end users. The Oracle Database Appliance Experience - Zip Zoom Zoom http://www.fuadarshad.com/2012/02/oracle-database-appliance-experience.html Off-the-shelf Oracle database servers http://normanweaver.wordpress.com/2011/10/10/off-the-shelf-oracle-database-servers/ Oracle Database Appliance – Deployment Steps http://marcel.vandewaters.nl/oracle/database-appliance/oracle-database-appliance-deployment-steps     See how easy it is to deploy an Oracle Database Appliance for high availability with RAC? Now for the meat of this post, which is the first in a series of posts describing tips for making the deployment of an ODA even easier. The key to the easy deployment of an Oracle Database Appliance is the Appliance Manager software, which does the actual software deployment and configuration, based on best practices. But in order for it to do that, it needs some basic information first, including system name, IP addresses, etc. That's where the Appliance Manager GUI comes in to play, taking a wizard approach to specifying the information needed.     Using the Appliance Manager GUI is pretty straight forward, stepping through several screens of information to enter data in typical wizard style. Like most configuration tasks, it helps to gather the required information before hand. But before you rush out to a committee meeting on what to use for host names, and rely on whatever IP addresses might be hanging around, make sure you are familiar with some of the auto-fill defaults for the Appliance Manager. I'll step through the key screens below to highlight the results of the auto-fill capability of the Appliance Manager GUI.     Depending on which of the 2 Configuration Types (Config Type screen) you choose, you will get a slightly different set of screens. The Typical configuration assumes certain default configuration choices and has the fewest screens, where as the Custom configuration gives you the most flexibility in what you configure from the start. In the examples below, I have used the Custom config type.     One of the first items you are asked for is the System Name (System Info screen). This is used to identify the system, but also as the base for the default hostnames on following screens. In this screen shot, the System Name is "oda".     When you get to the next screen (Generic Network screen), you enter your domain name, DNS IP address(es), and NTP IP address(es). Next up is the Public Network screen, seen below, where you will see the host name fields are automatically filled in with default host names based on the System Name, in this case "oda". The System Name is also the basis for default host names for the extra ethernet ports available for configuration as part of a Custom configuration, as seen in the 2nd screen shot below (Other Network). There is no requirement to use these host names, as you can easily edit any of the host names. This does make filling in the configuration details easier and less prone to "fat fingers" if you are OK with these host names. Here is a full list of the automatically filled in host names. 1 2 1-vip 2-vip -scan 1-ilom 2-ilom 1-net1 2-net1 1-net2 2-net2 1-net3 2-net3     Another auto-fill feature of the Appliance Manager GUI follows a common practice of deploying IP Addresses for a RAC cluster in sequential order. In the screen shot below, I entered the first IP address (Node1-IP), then hit Tab to move to the next field. As a result, the next 5 IP address fields were automatically filled in with the next 5 IP addresses sequentially from the first one I entered. As with the host names, these are not required, and can be changed to whatever your IP address values are. One note of caution though, if the first IP Address field (Node1-IP) is filled out and you click in that field and back out, the following 5 IP addresses will be set to the sequential default. If you don't use the sequential IP addresses, pay attention to where you click that mouse. :-)     In the screen shot below, by entering the netmask value in the Netmask field, in this case 255.255.255.0, the gateway value was auto-filled into the Gateway field, based on the IP addresses and netmask previously entered. As always, you can change this value.     My last 2 screen shots illustrate that the same sequential IP address autofill and netmask to gateway autofill works when entering the IP configuration details for the Integrated Lights Out Manager (ILOM) for both nodes. The time these auto-fill capabilities save in entering data is nice, but from my perspective not as important as the opportunity to avoid data entry errors. In my next post in this series, I will touch on the benefit of using the network validation capability of the Appliance Manager GUI prior to deploying an Oracle Database Appliance.

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• Scripting Part 1

  - by rbishop

  Dynamic Scripting is a large topic, so let me get a couple of things out of the way first. If you aren't familiar with JavaScript, I can suggest CodeAcademy's JavaScript series. There are also many other websites and books that cover JavaScript from every possible angle.The second thing we need to deal with is JavaScript as a programming language versus a JavaScript environment running in a web browser. Many books, tutorials, and websites completely blur these two together but they are in fact completely separate. What does this really mean in relation to DRM? Since DRM isn't a web browser, there are no document, window, history, screen, or location objects. There are no events like mousedown or click. Trying to call alert('hello!') in DRM will just cause an error. Those concepts are all related to an HTML document (web page) and are part of the Browser Object Model or Document Object Model. DRM has its own object model that exposes DRM-related objects. In practice, feel free to use those sorts of tutorials or practice within your browser; Many of the concepts are directly translatable to writing scripts in DRM. Just don't try to call document.getElementById in your property definition!I think learning by example tends to work the best, so let's try getting a list of all the unique property values for a given node and its children. var uniqueValues = {}; var childEnumerator = node.GetChildEnumerator(); while(childEnumerator.MoveNext()) { var propValue = childEnumerator.GetCurrent().PropValue("Custom.testpropstr1"); print(propValue); if(propValue != null && propValue != '' && !uniqueValues[propValue]) uniqueValues[propValue] = true; } var result = ''; for(var value in uniqueValues){ result += "Found value " + value + ","; } return result;  Now lets break this down piece by piece. var uniqueValues = {}; This declares a variable and initializes it as a new empty Object. You could also have written var uniqueValues = new Object(); Why use an object here? JavaScript objects can also function as a list of keys and we'll use that later to store each property value as a key on the object. var childEnumerator = node.GetChildEnumerator(); while(childEnumerator.MoveNext()) { This gets an enumerator for the node's children. The enumerator allows us to loop through the children one by one. If we wanted to get a filtered list of children, we would instead use ChildrenWith(). When we reach the end of the child list, the enumerator will return false for MoveNext() and that will stop the loop. var propValue = childEnumerator.GetCurrent().PropValue("Custom.testpropstr1"); print(propValue); if(propValue != null && propValue != '' && !uniqueValues[propValue]) uniqueValues[propValue] = true; } This gets the node the enumerator is currently pointing at, then calls PropValue() on it to get the value of a property. We then make sure the prop value isn't null or the empty string, then we make sure the value doesn't already exist as a key. Assuming it doesn't we add it as a key with a value (true in this case because it makes checking for an existing value faster when the value exists). A quick word on the print() function. When viewing the prop grid, running an export, or performing normal DRM operations it does nothing. If you have a lot of print() calls with complicated arguments it can slow your script down slightly, but otherwise has no effect. But when using the script editor, all the output of print() will be shown in the Warnings area. This gives you an extremely useful debugging tool to see what exactly a script is doing. var result = ''; for(var value in uniqueValues){ result += "Found value " + value + ","; } return result; Now we build a string by looping through all the keys in uniqueValues and adding that value to our string. The last step is to simply return the result. Hopefully this small example demonstrates some of the core Dynamic Scripting concepts. Next time, we can try checking for node references in other hierarchies to see if they are using duplicate property values.

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• WebSocket API 1.1 released!

  - by Pavel Bucek

  Its my please to announce that JSR 356 – Java API for WebSocket maintenance release ballot vote finished with majority of “yes” votes (actually, only one eligible voter did not vote, all other votes were “yeses”). New release is maintenance release and it addresses only one issue:  WEBSOCKET_SPEC-226. What changed in the 1.1? Version 1.1 is fully backwards compatible with version 1.0, there are only two methods added to javax.websocket.Session: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 /** * Register to handle to incoming messages in this conversation. A maximum of one message handler per * native websocket message type (text, binary, pong) may be added to each Session. I.e. a maximum * of one message handler to handle incoming text messages a maximum of one message handler for * handling incoming binary messages, and a maximum of one for handling incoming pong * messages. For further details of which message handlers handle which of the native websocket * message types please see {@link MessageHandler.Whole} and {@link MessageHandler.Partial}. * Adding more than one of any one type will result in a runtime exception. * * @param clazz   type of the message processed by message handler to be registered. * @param handler whole message handler to be added. * @throws IllegalStateException if there is already a MessageHandler registered for the same native *                               websocket message type as this handler. */ public void addMessageHandler(Class<T> clazz, MessageHandler.Whole<T> handler); /** * Register to handle to incoming messages in this conversation. A maximum of one message handler per * native websocket message type (text, binary, pong) may be added to each Session. I.e. a maximum * of one message handler to handle incoming text messages a maximum of one message handler for * handling incoming binary messages, and a maximum of one for handling incoming pong * messages. For further details of which message handlers handle which of the native websocket * message types please see {@link MessageHandler.Whole} and {@link MessageHandler.Partial}. * Adding more than one of any one type will result in a runtime exception. * * * @param clazz   type of the message processed by message handler to be registered. * @param handler partial message handler to be added. * @throws IllegalStateException if there is already a MessageHandler registered for the same native *                               websocket message type as this handler. */ public void addMessageHandler(Class<T> clazz, MessageHandler.Partial<T> handler); Why do we need to add those methods? Short and not precise version: to support Lambda expressions as MessageHandlers. Longer and slightly more precise explanation: old Session#addMessageHandler method (which is still there and works as it worked till now) does rely on getting the generic parameter during the runtime, which is not (always) possible. The unfortunate part is that it works for some common cases and the expert group did not catch this issue before 1.0 release because of that. The issue is really clearly visible when Lambdas are used as message handlers: 1 2 3 session.addMessageHandler(message -> { System.out.println("### Received: " + message); }); There is no way for the JSR 356 implementation to get the type of the used Lambda expression, thus this call will always result in an exception. Since all modern IDEs do recommend to use Lambda expressions when possible and MessageHandler interfaces are single method interfaces, it basically just scream “use Lambdas” all over the place but when you do that, the application will fail during runtime. Only solution we currently have is to explicitly provide the type of registered MessageHandler. (There might be another sometime in the future when generic type reification is introduced, but that is not going to happen soon enough). So the example above will then be: 1 2 3 session.addMessageHandler(String.class, message -> { System.out.println("### Received: " + message); }); and voila, it works. There are some limitations – you cannot do 1 List<String>.class , so you will need to encapsulate these types when you want to use them in MessageHandler implementation (something like “class MyType extends ArrayList<String>”). There is no better way how to solve this issue, because Java currently does not provide good way how to describe generic types. The api itself is available on maven central, look for javax.websocket:javax.websocket-api:1.1. The reference implementation is project Tyrus, which implements WebSocket API 1.1 from version 1.8.

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