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• Microsoft&rsquo;s new technical computing initiative

  - by Randy Walker

  I made a mental note from earlier in the year.  Microsoft literally buys computers by the truckload.  From what I understand, it’s a typical practice amongst large software vendors.  You plug a few wires in, you test it, and you instantly have mega tera tera flops (don’t hold me to that number).  Microsoft has been trying to plug away at their cloud services (named Azure).  Which, for the layman, means Microsoft runs your software on their computers, and as demand increases you can allocate more computing power on the fly. With this in mind, it doesn’t surprise me that I was recently sent an executive email concerning Microsoft’s new technical computing initiative.  I find it to be a great marketing idea with actual substance behind their real work.  From the programmer academic perspective, in college we dreamed about this type of processing power.  This has decades of computer science theory behind it. A copy of the email received.  (note that I almost deleted this email, thinking it was spam due to it’s length) We don't often think about how complex life really is. Take the relatively simple task of commuting to and from work: it is, in fact, a complicated interplay of variables such as weather, train delays, accidents, traffic patterns, road construction, etc. You can however, take steps to shorten your commute - using a good, predictive understanding of a few of these variables. In fact, you probably are already taking these inputs and instinctively building a predictive model that you act on daily to get to your destination more quickly. Now, when we apply the same method to very complex tasks, this modeling approach becomes much more challenging. Recent world events clearly demonstrated our inability to process vast amounts of information and variables that would have helped to more accurately predict the behavior of global financial markets or the occurrence and impact of a volcano eruption in Iceland. To make sense of issues like these, researchers, engineers and analysts create computer models of the almost infinite number of possible interactions in complex systems. But, they need increasingly more sophisticated computer models to better understand how the world behaves and to make fact-based predictions about the future. And, to do this, it requires a tremendous amount of computing power to process and examine the massive data deluge from cameras, digital sensors and precision instruments of all kinds. This is the key to creating more accurate and realistic models that expose the hidden meaning of data, which gives us the kind of insight we need to solve a myriad of challenges. We have made great strides in our ability to build these kinds of computer models, and yet they are still too difficult, expensive and time consuming to manage. Today, even the most complicated data-rich simulations cannot fully capture all of the intricacies and dependencies of the systems they are trying to model. That is why, across the scientific and engineering world, it is so hard to say with any certainty when or where the next volcano will erupt and what flight patterns it might affect, or to more accurately predict something like a global flu pandemic. So far, we just cannot collect, correlate and compute enough data to create an accurate forecast of the real world. But this is about to change. Innovations in technology are transforming our ability to measure, monitor and model how the world behaves. The implication for scientific research is profound, and it will transform the way we tackle global challenges like health care and climate change. It will also have a huge impact on engineering and business, delivering breakthroughs that could lead to the creation of new products, new businesses and even new industries. Because you are a subscriber to executive e-mails from Microsoft, I want you to be the first to know about a new effort focused specifically on empowering millions of the world's smartest problem solvers. Today, I am happy to introduce Microsoft's Technical Computing initiative. Our goal is to unleash the power of pervasive, accurate, real-time modeling to help people and organizations achieve their objectives and realize their potential. We are bringing together some of the brightest minds in the technical computing community across industry, academia and science at www.modelingtheworld.com to discuss trends, challenges and shared opportunities. New advances provide the foundation for tools and applications that will make technical computing more affordable and accessible where mathematical and computational principles are applied to solve practical problems. One day soon, complicated tasks like building a sophisticated computer model that would typically take a team of advanced software programmers months to build and days to run, will be accomplished in a single afternoon by a scientist, engineer or analyst working at the PC on their desktop. And as technology continues to advance, these models will become more complete and accurate in the way they represent the world. This will speed our ability to test new ideas, improve processes and advance our understanding of systems. Our technical computing initiative reflects the best of Microsoft's heritage. Ever since Bill Gates articulated the then far-fetched vision of "a computer on every desktop" in the early 1980's, Microsoft has been at the forefront of expanding the power and reach of computing to benefit the world. As someone who worked closely with Bill for many years at Microsoft, I am happy to share with you that the passion behind that vision is fully alive at Microsoft and is carried out in the creation of our new Technical Computing group. Enabling more people to make better predictions We have seen the impact of making greater computing power more available firsthand through our investments in high performance computing (HPC) over the past five years. Scientists, engineers and analysts in organizations of all sizes and sectors are finding that using distributed computational power creates societal impact, fuels scientific breakthroughs and delivers competitive advantages. For example, we have seen remarkable results from some of our current customers: Malaria strikes 300,000 to 500,000 people around the world each year. To help in the effort to eradicate malaria worldwide, scientists at Intellectual Ventures use software that simulates how the disease spreads and would respond to prevention and control methods, such as vaccines and the use of bed nets. Technical computing allows researchers to model more detailed parameters for more accurate results and receive those results in less than an hour, rather than waiting a full day. Aerospace engineering firm, a.i. solutions, Inc., needed a more powerful computing platform to keep up with the increasingly complex computational needs of its customers: NASA, the Department of Defense and other government agencies planning space flights. To meet that need, it adopted technical computing. Now, a.i. solutions can produce detailed predictions and analysis of the flight dynamics of a given spacecraft, from optimal launch times and orbit determination to attitude control and navigation, up to eight times faster. This enables them to avoid mistakes in any areas that can cause a space mission to fail and potentially result in the loss of life and millions of dollars. Western & Southern Financial Group faced the challenge of running ever larger and more complex actuarial models as its number of policyholders and products grew and regulatory requirements changed. The company chose an actuarial solution that runs on technical computing technology. The solution is easy for the company's IT staff to manage and adjust to meet business needs. The new solution helps the company reduce modeling time by up to 99 percent - letting the team fine-tune its models for more accurate product pricing and financial projections. Our Technical Computing direction Collaborating closely with partners across industry and academia, we must now extend the reach of technical computing even further to help predictive modelers and data explorers make faster, more accurate predictions. As we build the Technical Computing initiative, we will invest in three core areas: Technical computing to the cloud: Microsoft will play a leading role in bringing technical computing power to scientists, engineers and analysts through the cloud. Existing high- performance computing users will benefit from the ability to augment their on-premises systems with cloud resources that enable 'just-in-time' processing. This platform will help ensure processing resources are available whenever they are needed-reliably, consistently and quickly. Simplify parallel development: Today, computers are shipping with more processing power than ever, including multiple cores, but most modern software only uses a small amount of the available processing power. Parallel programs are extremely difficult to write, test and trouble shoot. However, a consistent model for parallel programming can help more developers unlock the tremendous power in today's modern computers and enable a new generation of technical computing. We are delivering new tools to automate and simplify writing software through parallel processing from the desktop... to the cluster... to the cloud. Develop powerful new technical computing tools and applications: We know scientists, engineers and analysts are pushing common tools (i.e., spreadsheets and databases) to the limits with complex, data-intensive models. They need easy access to more computing power and simplified tools to increase the speed of their work. We are building a platform to do this. Our development efforts will yield new, easy-to-use tools and applications that automate data acquisition, modeling, simulation, visualization, workflow and collaboration. This will allow them to spend more time on their work and less time wrestling with complicated technology. Thinking bigger There is so much left to be discovered and so many questions yet to be answered in the fascinating world around us. We believe the technical computing community will show us that we have not seen anything yet. Imagine just some of the breakthroughs this community could make possible: Better predictions to help improve the understanding of pandemics, contagion and global health trends. Climate change models that predict environmental, economic and human impact, accessible in real-time during key discussions and debates. More accurate prediction of natural disasters and their impact to develop more effective emergency response plans. With an ambitious charter in hand, this new team is ready to build on our progress to-date and execute Microsoft's technical computing vision over the months and years ahead. We will steadily invest in the right technologies, tools and talent, and work to bring together the technical computing community. I invite you to visit www.modelingtheworld.com today. We welcome your ideas and feedback. I look forward to making this journey with you and others who want to answer the world's biggest questions, discover solutions to problems that seem impossible and uncover a host of new opportunities to change the world we live in for the better. Bob

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• Spooling in SQL execution plans

  - by Rob Farley

  Sewing has never been my thing. I barely even know the terminology, and when discussing this with American friends, I even found out that half the words that Americans use are different to the words that English and Australian people use. That said – let’s talk about spools! In particular, the Spool operators that you find in some SQL execution plans. This post is for T-SQL Tuesday, hosted this month by me! I’ve chosen to write about spools because they seem to get a bad rap (even in my song I used the line “There’s spooling from a CTE, they’ve got recursion needlessly”). I figured it was worth covering some of what spools are about, and hopefully explain why they are remarkably necessary, and generally very useful. If you have a look at the Books Online page about Plan Operators, at http://msdn.microsoft.com/en-us/library/ms191158.aspx, and do a search for the word ‘spool’, you’ll notice it says there are 46 matches. 46! Yeah, that’s what I thought too... Spooling is mentioned in several operators: Eager Spool, Lazy Spool, Index Spool (sometimes called a Nonclustered Index Spool), Row Count Spool, Spool, Table Spool, and Window Spool (oh, and Cache, which is a special kind of spool for a single row, but as it isn’t used in SQL 2012, I won’t describe it any further here). Spool, Table Spool, Index Spool, Window Spool and Row Count Spool are all physical operators, whereas Eager Spool and Lazy Spool are logical operators, describing the way that the other spools work. For example, you might see a Table Spool which is either Eager or Lazy. A Window Spool can actually act as both, as I’ll mention in a moment. In sewing, cotton is put onto a spool to make it more useful. You might buy it in bulk on a cone, but if you’re going to be using a sewing machine, then you quite probably want to have it on a spool or bobbin, which allows it to be used in a more effective way. This is the picture that I want you to think about in relation to your data. I’m sure you use spools every time you use your sewing machine. I know I do. I can’t think of a time when I’ve got out my sewing machine to do some sewing and haven’t used a spool. However, I often run SQL queries that don’t use spools. You see, the data that is consumed by my query is typically in a useful state without a spool. It’s like I can just sew with my cotton despite it not being on a spool! Many of my favourite features in T-SQL do like to use spools though. This looks like a very similar query to before, but includes an OVER clause to return a column telling me the number of rows in my data set. I’ll describe what’s going on in a few paragraphs’ time. So what does a Spool operator actually do? The spool operator consumes a set of data, and stores it in a temporary structure, in the tempdb database. This structure is typically either a Table (ie, a heap), or an Index (ie, a b-tree). If no data is actually needed from it, then it could also be a Row Count spool, which only stores the number of rows that the spool operator consumes. A Window Spool is another option if the data being consumed is tightly linked to windows of data, such as when the ROWS/RANGE clause of the OVER clause is being used. You could maybe think about the type of spool being like whether the cotton is going onto a small bobbin to fit in the base of the sewing machine, or whether it’s a larger spool for the top. A Table or Index Spool is either Eager or Lazy in nature. Eager and Lazy are Logical operators, which talk more about the behaviour, rather than the physical operation. If I’m sewing, I can either be all enthusiastic and get all my cotton onto the spool before I start, or I can do it as I need it. “Lazy” might not the be the best word to describe a person – in the SQL world it describes the idea of either fetching all the rows to build up the whole spool when the operator is called (Eager), or populating the spool only as it’s needed (Lazy). Window Spools are both physical and logical. They’re eager on a per-window basis, but lazy between windows. And when is it needed? The way I see it, spools are needed for two reasons. 1 – When data is going to be needed AGAIN. 2 – When data needs to be kept away from the original source. If you’re someone that writes long stored procedures, you are probably quite aware of the second scenario. I see plenty of stored procedures being written this way – where the query writer populates a temporary table, so that they can make updates to it without risking the original table. SQL does this too. Imagine I’m updating my contact list, and some of my changes move data to later in the book. If I’m not careful, I might update the same row a second time (or even enter an infinite loop, updating it over and over). A spool can make sure that I don’t, by using a copy of the data. This problem is known as the Halloween Effect (not because it’s spooky, but because it was discovered in late October one year). As I’m sure you can imagine, the kind of spool you’d need to protect against the Halloween Effect would be eager, because if you’re only handling one row at a time, then you’re not providing the protection... An eager spool will block the flow of data, waiting until it has fetched all the data before serving it up to the operator that called it. In the query below I’m forcing the Query Optimizer to use an index which would be upset if the Name column values got changed, and we see that before any data is fetched, a spool is created to load the data into. This doesn’t stop the index being maintained, but it does mean that the index is protected from the changes that are being done. There are plenty of times, though, when you need data repeatedly. Consider the query I put above. A simple join, but then counting the number of rows that came through. The way that this has executed (be it ideal or not), is to ask that a Table Spool be populated. That’s the Table Spool operator on the top row. That spool can produce the same set of rows repeatedly. This is the behaviour that we see in the bottom half of the plan. In the bottom half of the plan, we see that the a join is being done between the rows that are being sourced from the spool – one being aggregated and one not – producing the columns that we need for the query. Table v Index When considering whether to use a Table Spool or an Index Spool, the question that the Query Optimizer needs to answer is whether there is sufficient benefit to storing the data in a b-tree. The idea of having data in indexes is great, but of course there is a cost to maintaining them. Here we’re creating a temporary structure for data, and there is a cost associated with populating each row into its correct position according to a b-tree, as opposed to simply adding it to the end of the list of rows in a heap. Using a b-tree could even result in page-splits as the b-tree is populated, so there had better be a reason to use that kind of structure. That all depends on how the data is going to be used in other parts of the plan. If you’ve ever thought that you could use a temporary index for a particular query, well this is it – and the Query Optimizer can do that if it thinks it’s worthwhile. It’s worth noting that just because a Spool is populated using an Index Spool, it can still be fetched using a Table Spool. The details about whether or not a Spool used as a source shows as a Table Spool or an Index Spool is more about whether a Seek predicate is used, rather than on the underlying structure. Recursive CTE I’ve already shown you an example of spooling when the OVER clause is used. You might see them being used whenever you have data that is needed multiple times, and CTEs are quite common here. With the definition of a set of data described in a CTE, if the query writer is leveraging this by referring to the CTE multiple times, and there’s no simplification to be leveraged, a spool could theoretically be used to avoid reapplying the CTE’s logic. Annoyingly, this doesn’t happen. Consider this query, which really looks like it’s using the same data twice. I’m creating a set of data (which is completely deterministic, by the way), and then joining it back to itself. There seems to be no reason why it shouldn’t use a spool for the set described by the CTE, but it doesn’t. On the other hand, if we don’t pull as many columns back, we might see a very different plan. You see, CTEs, like all sub-queries, are simplified out to figure out the best way of executing the whole query. My example is somewhat contrived, and although there are plenty of cases when it’s nice to give the Query Optimizer hints about how to execute queries, it usually doesn’t do a bad job, even without spooling (and you can always use a temporary table). When recursion is used, though, spooling should be expected. Consider what we’re asking for in a recursive CTE. We’re telling the system to construct a set of data using an initial query, and then use set as a source for another query, piping this back into the same set and back around. It’s very much a spool. The analogy of cotton is long gone here, as the idea of having a continual loop of cotton feeding onto a spool and off again doesn’t quite fit, but that’s what we have here. Data is being fed onto the spool, and getting pulled out a second time when the spool is used as a source. (This query is running on AdventureWorks, which has a ManagerID column in HumanResources.Employee, not AdventureWorks2012) The Index Spool operator is sucking rows into it – lazily. It has to be lazy, because at the start, there’s only one row to be had. However, as rows get populated onto the spool, the Table Spool operator on the right can return rows when asked, ending up with more rows (potentially) getting back onto the spool, ready for the next round. (The Assert operator is merely checking to see if we’ve reached the MAXRECURSION point – it vanishes if you use OPTION (MAXRECURSION 0), which you can try yourself if you like). Spools are useful. Don’t lose sight of that. Every time you use temporary tables or table variables in a stored procedure, you’re essentially doing the same – don’t get upset at the Query Optimizer for doing so, even if you think the spool looks like an expensive part of the query. I hope you’re enjoying this T-SQL Tuesday. Why not head over to my post that is hosting it this month to read about some other plan operators? At some point I’ll write a summary post – once I have you should find a comment below pointing at it. @rob_farley

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• How To Make Hundreds of Complex Photo Edits in Seconds With Photoshop Actions

  - by Eric Z Goodnight

  Have a huge folder of images needing tweaks? A few hundred adjustments may seem like a big, time consuming job—but read one to see how Photoshop can do repetitive tasks automatically, even if you don’t know how to program! Photoshop Actions are a simple way to program simple routines in Photoshop, and are a great time saver, allowing you to re-perform tasks over and over, saving you minutes or hours, depending on the job you have to work on. See how any bunch of images and even some fairly complicated photo tweaking can be done automatically to even hundreds of images at once. When Can I use Photoshop Actions? Photoshop actions are a way of recording the tools, menus, and keys pressed while using the program. Each time you use a tool, adjust a color, or use the brush, it can be recorded and played back over any file Photoshop can open. While it isn’t perfect and can get very confused if not set up correctly, it can automate editing hundreds of images, saving you hours and hours if you have big jobs with complex edits. The image illustrated above is a template for a polaroid-style picture frame. If you had several hundred images, it would actually be a simple matter to use Photoshop Actions to create hundreds of new images inside the frame in almost no time at all. Let’s take a look at how a simple folder of images and some Image editing automation can turn lots of work into a simple and easy job. Creating a New Action Actions is a default part of the “Essentials” panel set Photoshop begins with as a default. If you can’t see the panel button under the “History” button, you can find Actions by going to Window > Actions or pressing Alt + F9. Click the in the Actions Panel, pictured in the previous illustration on the left. Choose to create a “New Set” in order to begin creating your own custom Actions. Name your action set whatever you want. Names are not relevant, you’ll simply want to make it obvious that you have created it. Click OK. Look back in the layers panel. You’ll see your new Set of actions has been added to the list. Click it to highlight it before going on. Click the again to create a “New Action” in your new set. If you care to name your action, go ahead. Name it after whatever it is you’re hoping to do—change the canvas size, tint all your pictures blue, send your image to the printer in high quality, or run multiple filters on images. The name is for your own usage, so do what suits you best. Note that you can simplify your process by creating shortcut keys for your actions. If you plan to do hundreds of edits with your actions, this might be a good idea. If you plan to record an action to use every time you use Photoshop, this might even be an invaluable step. When you create a new Action, Photoshop automatically begins recording everything you do. It does not record the time in between steps, but rather only the data from each step. So take your time when recording and make sure you create your actions the way you want them. The square button stops recording, and the circle button starts recording again. With these basics ready, we can take a look at a sample Action. Recording a Sample Action Photoshop will remember everything you input into it when it is recording, even specific photographs you open. So begin recording your action when your first photo is already open. Once your first image is open, click the record button. If you’re already recording, continue on. Using the File > Place command to insert the polaroid image can be easier for Actions to deal with. Photoshop can record with multiple open files, but it often gets confused when you try it. Keep your recordings as simple as possible to ensure your success. When the image is placed in, simply press enter to render it. Select your background layer in your layers panel. Your recording should be following along with no trouble. Double click this layer. Double clicking your background layer will create a new layer from it. Allow it to be renamed “Layer 0” and press OK. Move the “polaroid” layer to the bottom by selecting it and dragging it down below “Layer 0” in the layers panel. Right click “Layer 0” and select “Create Clipping Mask.” The JPG image is cropped to the layer below it. Coincidentally, all actions described here are being recorded perfectly, and are reproducible. Cursor actions, like the eraser, brush, or bucket fill don’t record well, because the computer uses your mouse movements and coordinates, which may need to change from photo to photo. Click the to set your Photograph layer to a “Screen” blending mode. This will make the image disappear when it runs over the white parts of the polaroid image. With your image layer (Layer 0) still selected, navigate to Edit > Transform > Scale. You can use the mouse to resize your Layer 0, but Actions work better with absolute numbers. Visit the Width and Height adjustments in the top options panel. Click the chain icon to link them together, and adjust them numerically. Depending on your needs, you may need to use more or less than 30%. Your image will resize to your specifications. Press enter to render, or click the check box in the top right of your application. + Click on your bottom layer, or “polaroid” in this case. This creates a selection of the bottom layer. Navigate to Image > Crop in order to crop down to your bottom layer selection Your image is now resized to your bottommost layer, and Photoshop is still recording to that effect. For additional effect, we can navigate to Image > Image Rotation > Arbitrary to rotate our image by a small tilt. Choosing 3 degrees clockwise , we click OK to render our choice. Our image is rotated, and this step is recorded. Photoshop will even record when you save your files. With your recording still going, find File > Save As. You can easily tell Photoshop to save in a new folder, other than the one you have been working in, so that your files aren’t overwritten. Navigate to any folder you wish, but do not change the filename. If you change the filename, Photoshop will record that name, and save all your images under whatever you type. However, you can change your filetype without recording an absolute filename. Use the pulldown tab and select a different filetype—in this instance, PNG. Simply click “Save” to create a new PNG based on your actions. Photoshop will record the destination and the change in filetype. If you didn’t edit the name of your file, it will always use the variable filename of any image you open. (This is very important if you want to edit hundreds of images at once!) Click File > Close or the red “X” in the corner to close your filetype. Photoshop can record that as well. Since we have already saved our image as a JPG, click “NO” to not overwrite your original image. Photoshop will also record your choice of “NO” for subsequent images. In your Actions panel, click the stop button to complete your action. You can always click the record button to add more steps later, if you want. This is how your new action looks with its steps expanded. Curious how to put it into effect? Read on to see how simple it is to use that recording you just made. Editing Lots of Images with Your New Action Open a large number of images—as many as you care to work with. Your action should work immediately with every image on screen, although you may have to test and re-record, depending on how you did. Actions don’t require any programming knowledge, but often can get confused or work in a counter-intuitive way. Record your action until it is perfect. If it works once without errors, it’s likely to work again and again! Find the “Play” button in your Actions Panel. With your custom action selected, click “Play” and your routine will edit, save, and close each file for you. Keep bashing “Play” for each open file, and it will keep saving and creating new files until you run out of work you need to do. And in mere moments, a complicated stack of work is done. Photoshop actions can be very complicated, far beyond what is illustrated here, and can even be combined with scripts and other actions, creating automated creation of potentially very complex files, or applying filters to an entire portfolio of digital photos. Have questions or comments concerning Graphics, Photos, Filetypes, or Photoshop? Send your questions to [email protected], and they may be featured in a future How-To Geek Graphics article. Image Credits: All images copyright Stephanie Pragnell and author Eric Z Goodnight, protected under Creative Commons. 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• Restricting joystick within a radius of center

  - by Phil

  I'm using Unity3d iOs and am using the example joysticks that came with one of the packages. It works fine but the area the joystick moves in is a rectangle which is unintuitive for my type of game. I can figure out how to see if the distance between the center and the current point is too far but I can't figure out how to constrain it to a certain distance without interrupting the finger tracking. Here's the relevant code: using UnityEngine; using System.Collections; public class Boundary { public Vector2 min = Vector2.zero; public Vector2 max = Vector2.zero; } public class Joystick : MonoBehaviour{ static private Joystick[] joysticks; // A static collection of all joysticks static private bool enumeratedJoysticks=false; static private float tapTimeDelta = 0.3f; // Time allowed between taps public bool touchPad; // Is this a TouchPad? public Rect touchZone; public Vector2 deadZone = Vector2.zero; // Control when position is output public bool normalize = false; // Normalize output after the dead-zone? public Vector2 position; // [-1, 1] in x,y public int tapCount; // Current tap count private int lastFingerId = -1; // Finger last used for this joystick private float tapTimeWindow; // How much time there is left for a tap to occur private Vector2 fingerDownPos; private float fingerDownTime; private float firstDeltaTime = 0.5f; private GUITexture gui; // Joystick graphic private Rect defaultRect; // Default position / extents of the joystick graphic private Boundary guiBoundary = new Boundary(); // Boundary for joystick graphic public Vector2 guiTouchOffset; // Offset to apply to touch input private Vector2 guiCenter; // Center of joystick private Vector3 tmpv3; private Rect tmprect; private Color tmpclr; public float allowedDistance; public enum JoystickType { movement, rotation } public JoystickType joystickType; public void Start() { // Cache this component at startup instead of looking up every frame gui = (GUITexture) GetComponent( typeof(GUITexture) ); // Store the default rect for the gui, so we can snap back to it defaultRect = gui.pixelInset; if ( touchPad ) { // If a texture has been assigned, then use the rect ferom the gui as our touchZone if ( gui.texture ) touchZone = gui.pixelInset; } else { // This is an offset for touch input to match with the top left // corner of the GUI guiTouchOffset.x = defaultRect.width * 0.5f; guiTouchOffset.y = defaultRect.height * 0.5f; // Cache the center of the GUI, since it doesn't change guiCenter.x = defaultRect.x + guiTouchOffset.x; guiCenter.y = defaultRect.y + guiTouchOffset.y; // Let's build the GUI boundary, so we can clamp joystick movement guiBoundary.min.x = defaultRect.x - guiTouchOffset.x; guiBoundary.max.x = defaultRect.x + guiTouchOffset.x; guiBoundary.min.y = defaultRect.y - guiTouchOffset.y; guiBoundary.max.y = defaultRect.y + guiTouchOffset.y; } } public void Disable() { gameObject.active = false; enumeratedJoysticks = false; } public void ResetJoystick() { if (joystickType != JoystickType.rotation) { //Don't do anything if turret mode // Release the finger control and set the joystick back to the default position gui.pixelInset = defaultRect; lastFingerId = -1; position = Vector2.zero; fingerDownPos = Vector2.zero; if ( touchPad ){ tmpclr = gui.color; tmpclr.a = 0.025f; gui.color = tmpclr; } } else { //gui.pixelInset = defaultRect; lastFingerId = -1; position = position; fingerDownPos = fingerDownPos; if ( touchPad ){ tmpclr = gui.color; tmpclr.a = 0.025f; gui.color = tmpclr; } } } public bool IsFingerDown() { return (lastFingerId != -1); } public void LatchedFinger( int fingerId ) { // If another joystick has latched this finger, then we must release it if ( lastFingerId == fingerId ) ResetJoystick(); } public void Update() { if ( !enumeratedJoysticks ) { // Collect all joysticks in the game, so we can relay finger latching messages joysticks = (Joystick[]) FindObjectsOfType( typeof(Joystick) ); enumeratedJoysticks = true; } //CHeck if distance is over the allowed amount //Get centerPosition //Get current position //Get distance //If over, don't allow int count = iPhoneInput.touchCount; // Adjust the tap time window while it still available if ( tapTimeWindow > 0 ) tapTimeWindow -= Time.deltaTime; else tapCount = 0; if ( count == 0 ) ResetJoystick(); else { for(int i = 0;i < count; i++) { iPhoneTouch touch = iPhoneInput.GetTouch(i); Vector2 guiTouchPos = touch.position - guiTouchOffset; bool shouldLatchFinger = false; if ( touchPad ) { if ( touchZone.Contains( touch.position ) ) shouldLatchFinger = true; } else if ( gui.HitTest( touch.position ) ) { shouldLatchFinger = true; } // Latch the finger if this is a new touch if ( shouldLatchFinger && ( lastFingerId == -1 || lastFingerId != touch.fingerId ) ) { if ( touchPad ) { tmpclr = gui.color; tmpclr.a = 0.15f; gui.color = tmpclr; lastFingerId = touch.fingerId; fingerDownPos = touch.position; fingerDownTime = Time.time; } lastFingerId = touch.fingerId; // Accumulate taps if it is within the time window if ( tapTimeWindow > 0 ) { tapCount++; print("tap" + tapCount.ToString()); } else { tapCount = 1; print("tap" + tapCount.ToString()); //Tell gameobject that player has tapped turret joystick if (joystickType == JoystickType.rotation) { //TODO: Call! } tapTimeWindow = tapTimeDelta; } // Tell other joysticks we've latched this finger foreach ( Joystick j in joysticks ) { if ( j != this ) j.LatchedFinger( touch.fingerId ); } } if ( lastFingerId == touch.fingerId ) { // Override the tap count with what the iPhone SDK reports if it is greater // This is a workaround, since the iPhone SDK does not currently track taps // for multiple touches if ( touch.tapCount > tapCount ) tapCount = touch.tapCount; if ( touchPad ) { // For a touchpad, let's just set the position directly based on distance from initial touchdown position.x = Mathf.Clamp( ( touch.position.x - fingerDownPos.x ) / ( touchZone.width / 2 ), -1, 1 ); position.y = Mathf.Clamp( ( touch.position.y - fingerDownPos.y ) / ( touchZone.height / 2 ), -1, 1 ); } else { // Change the location of the joystick graphic to match where the touch is tmprect = gui.pixelInset; tmprect.x = Mathf.Clamp( guiTouchPos.x, guiBoundary.min.x, guiBoundary.max.x ); tmprect.y = Mathf.Clamp( guiTouchPos.y, guiBoundary.min.y, guiBoundary.max.y ); //Check distance float distance = Vector2.Distance(new Vector2(defaultRect.x, defaultRect.y), new Vector2(tmprect.x, tmprect.y)); float angle = Vector2.Angle(new Vector2(defaultRect.x, defaultRect.y), new Vector2(tmprect.x, tmprect.y)); if (distance < allowedDistance) { //Ok gui.pixelInset = tmprect; } else { //This is where I don't know what to do... } } if ( touch.phase == iPhoneTouchPhase.Ended || touch.phase == iPhoneTouchPhase.Canceled ) ResetJoystick(); } } } if ( !touchPad ) { // Get a value between -1 and 1 based on the joystick graphic location position.x = ( gui.pixelInset.x + guiTouchOffset.x - guiCenter.x ) / guiTouchOffset.x; position.y = ( gui.pixelInset.y + guiTouchOffset.y - guiCenter.y ) / guiTouchOffset.y; } // Adjust for dead zone float absoluteX = Mathf.Abs( position.x ); float absoluteY = Mathf.Abs( position.y ); if ( absoluteX < deadZone.x ) { // Report the joystick as being at the center if it is within the dead zone position.x = 0; } else if ( normalize ) { // Rescale the output after taking the dead zone into account position.x = Mathf.Sign( position.x ) * ( absoluteX - deadZone.x ) / ( 1 - deadZone.x ); } if ( absoluteY < deadZone.y ) { // Report the joystick as being at the center if it is within the dead zone position.y = 0; } else if ( normalize ) { // Rescale the output after taking the dead zone into account position.y = Mathf.Sign( position.y ) * ( absoluteY - deadZone.y ) / ( 1 - deadZone.y ); } } } So the later portion of the code handles the updated position of the joystick thumb. This is where I'd like it to track the finger position in a direction it still is allowed to move (like if the finger is too far up and slightly to the +X I'd like to make sure the joystick is as close in X and Y as allowed within the radius) Thanks for reading!

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• BizTalk: History of one project architecture

  - by Leonid Ganeline

  "In the beginning God made heaven and earth. Then he started to integrate." At the very start was the requirement: integrate two working systems. Small digging up: It was one system. It was good but IT guys want to change it to the new one, much better, chipper, more flexible, and more progressive in technologies, more suitable for the future, for the faster world and hungry competitors. One thing. One small, little thing. We cannot turn off the old system (call it A, because it was the first), turn on the new one (call it B, because it is second but not the last one). The A has a hundreds users all across a country, they must study B. A still has a lot nice custom features, home-made features that cannot disappear. These features have to be moved to the B and it is a long process, months and months of redevelopment. So, the decision was simple. Let’s move not jump, let’s both systems working side-by-side several months. In this time we could teach the users and move all custom A’s special functionality to B. That automatically means both systems should work side-by-side all these months and use the same data. Data in A and B must be in sync. That’s how the integration projects get birth. Moreover, the specific of the user tasks requires the both systems must be in sync in real-time. Nightly synchronization is not working, absolutely.   First draft The first draft seems simple. Both systems keep data in SQL databases. When data changes, the Create, Update, Delete operations performed on the data, and the sync process could be started. The obvious decision is to use triggers on tables. When we are talking about data, we are talking about several entities. For example, Orders and Items [in Orders]. We decided to use the BizTalk Server to synchronize systems. Why it was chosen is another story. Second draft   Let’s take an example how it works in more details. 1.       User creates a new entity in the A system. This fires an insert trigger on the entity table. Trigger has to pass the message “Entity created”. This message includes all attributes of the new entity, but I focused on the Id of this entity in the A system. Notation for this message is id.A. System A sends id.A to the BizTalk Server. 2.       BizTalk transforms id.A to the format of the system B. This is easiest part and I will not focus on this kind of transformations in the following text. The message on the picture is still id.A but it is in slightly different format, that’s why it is changing in color. BizTalk sends id.A to the system B. 3.       The system B creates the entity on its side. But it uses different id-s for entities, these id-s are id.B. System B saves id.A+id.B. System B sends the message id.A+id.B back to the BizTalk. 4.       BizTalk sends the message id.A+id.B to the system A. 5.       System A saves id.A+id.B. Why both id-s should be saved on both systems? It was one of the next requirements. Users of both systems have to know the systems are in sync or not in sync. Users working with the entity on the system A can see the id.B and use it to switch to the system B and work there with the copy of the same entity. The decision was to store the pairs of entity id-s on both sides. If there is only one id, the entities are not in sync yet (for the Create operation). Third draft Next problem was the reliability of the synchronization. The synchronizing process can be interrupted on each step, when message goes through the wires. It can be communication problem, timeout, temporary shutdown one of the systems, the second system cannot be synchronized by some internal reason. There were several potential problems that prevented from enclosing the whole synchronization process in one transaction. Decision was to restart the whole sync process if it was not finished (in case of the error). For this purpose was created an additional service. Let’s call it the Resync service. We still keep the id pairs in both systems, but only for the fast access not for the synchronization process. For the synchronizing these id-s now are kept in one main place, in the Resync service database. The Resync service keeps record as: ·       Id.A ·       Id.B ·       Entity.Type ·       Operation (Create, Update, Delete) ·       IsSyncStarted (true/false) ·       IsSyncFinished (true/false0 The example now looks like: 1.       System A creates id.A. id.A is saved on the A. Id.A is sent to the BizTalk. 2.       BizTalk sends id.A to the Resync and to the B. id.A is saved on the Resync. 3.       System B creates id.B. id.A+id.B are saved on the B. id.A+id.B are sent to the BizTalk. 4.       BizTalk sends id.A+id.B to the Resync and to the A. id.A+id.B are saved on the Resync. 5.       id.A+id.B are saved on the B. Resync changes the IsSyncStarted and IsSyncFinished flags accordingly. The Resync service implements three main methods: ·       Save (id.A, Entity.Type, Operation) ·       Save (id.A, id.B, Entity.Type, Operation) ·       Resync () Two Save() are used to save id-s to the service storage. See in the above example, in 2 and 4 steps. What about the Resync()? It is the method that finishes the interrupted synchronization processes. If Save() is started by the trigger event, the Resync() is working as an independent process. It periodically scans the Resync storage to find out “unfinished” records. Then it restarts the synchronization processes. It tries to synchronize them several times then gives up.     One more thing, both systems A and B must tolerate duplicates of one synchronizing process. Say on the step 3 the system B was not able to send id.A+id.B back. The Resync service must restart the synchronization process that will send the id.A to B second time. In this case system B must just send back again also created id.A+id.B pair without errors. That means “tolerate duplicates”. Fourth draft Next draft was created only because of the aesthetics. As it always happens, aesthetics gave significant performance gain to the whole system. First was the stupid question. Why do we need this additional service with special database? Can we just master the BizTalk to do something like this Resync() does? So the Resync orchestration is doing the same thing as the Resync service. It is started by the Id.A and finished by the id.A+id.B message. The first works as a Start message, the second works as a Finish message.     Here is a diagram the whole process without errors. It is pretty straightforward. The Resync orchestration is waiting for the Finish message specific period of time then resubmits the Id.A message. It resubmits the Id.A message specific number of times then gives up and gets suspended. It can be resubmitted then it starts the whole process again: waiting [, resubmitting [, get suspended]], finishing. Tuning up The Resync orchestration resubmits the id.A message with special “Resubmitted” flag. The subscription filter on the Resync orchestration includes predicate as (Resubmit_Flag != “Resubmitted”). That means only the first Sync orchestration starts the Resync orchestration. Other Sync orchestration instantiated by the resubmitting can finish this Resync orchestration but cannot start another instance of the Resync   Here is a diagram where system B was inaccessible for some period of time. The Resync orchestration resubmitted the id.A two times. Then system B got the response the id.A+id.B and this finished the Resync service execution. What is interesting about this, there were submitted several identical id.A messages and only one id.A+id.B message. Because of this, the system B and the Resync must tolerate the duplicate messages. We also told about this requirement for the system B. Now the same requirement is for the Resunc. Let’s assume the system B was very slow in the first response and the Resync service had time to resubmit two id.A messages. System B responded not, as it was in previous case, with one id.A+id.B but with two id.A+id.B messages. First of them finished the Resync execution for the id.A. What about the second id.A+id.B? Where it goes? So, we have to add one more internal requirement. The whole solution must tolerate many identical id.A+id.B messages. It is easy task with the BizTalk. I added the “SinkExtraMessages” subscriber (orchestration with one receive shape), that just get these messages and do nothing. Real design Real architecture is much more complex and interesting. In reality each system can submit several id.A almost simultaneously and completely unordered. There are not only the “Create entity” operation but the Update and Delete operations. And these operations relate each other. Say the Update operation after Delete means not the same as Update after Create. In reality there are entities related each other. Say the Order and Order Items. Change on one of it could start the series of the operations on another. Moreover, the system internals are the “black boxes” and we cannot predict the exact content and order of the operation series. It worth to say, I had to spend a time to manage the zombie message problems. The zombies are still here, but this is not a problem now. And this is another story. What is interesting in the last design? One orchestration works to help another to be more reliable. Why two orchestration design is more reliable, isn’t it something strange? The Synch orchestration takes all the message exchange between systems, here is the area where most of the errors could happen. The Resync orchestration sends and receives messages only within the BizTalk server. Is there another design? Sure. All Resync functionality could be implemented inside the Sync orchestration. Hey guys, some other ideas?

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• CodePlex Daily Summary for Wednesday, May 07, 2014

  CodePlex Daily Summary for Wednesday, May 07, 2014Popular ReleasesSeal Report: Seal Report 1.4: New Features: Report Designer: New option to convert a Report Source into a Repository Source. Report Designer: New contextual helper menus to select, remove, copy, prompt elements in a model. Web Server: New option to expand sub-folders displayed in the tree view. Web Server: Web Folder Description File can be a .cshtml file to display a MVC View. Views: additional CSS parameters for some DIVs. NVD3 Chart: Some default configuration values have been changed. Issues Addressed:16 ...Magick.NET: Magick.NET 6.8.9.002: Magick.NET linked with ImageMagick 6.8.9.0.VidCoder: 1.5.22 Beta: Added ability to burn SRT subtitles. Updated to HandBrake SVN 6169. Added checks to prevent VidCoder from running with a database version newer than it expects. Tooltips in the Advanced Video panel now trigger on the field labels as well as the fields themselves. Fixed updating preset/profile/tune/level settings on changing video encoder. This should resolve some problems with QSV encoding. Fixed tunes and profiles getting set to blank when switching between x264 and x265. Fixed co...NuGet: NuGet 2.8.2: We will be releasing a 2.8.2 version of our own NuGet packages and the NuGet.exe command-line tool. The 2.8.2 release will not include updated VS or WebMatrix extensions. NuGet.Server.Extensions.dll needs to be used alongside NuGet-Signed.exe to provide the NuGet.exe mirror functionality.DNN CMS Platform: 07.03.00 BETA (Not For Production Use): DNN 7.3 release is focused on performance and we have made a variety of changes to improve the run-time characteristics of the platform. End users will notice faster page response time and administrators will appreciate a more responsive user experience, especially on larger scale web sites. This is a BETA release and is NOT recommended for production use. There is no upgrade path offered from this release to the final DNN 7.3 release. Known Issues - The Telerik RAD Controls for ASP.NET AJA...babelua: 1.5.3: V1.5.3 - 2014.5.6Stability improvement: support relative path when debugging lua files; improve variable view function in debugger; fix a bug that when a file is loaded at runtime , its breakpoints would not take effect; some other bug fix; New feature: improve tool windows color scheme to look better with different vs themes; comment/uncomment code block easily; some other improve;CTI Text Encryption: CTI Text Encryption 5.0: Improve encryption algorithm. Simplify all-non encryption related mechanism (Simplify user interface)SmartStore.NET - Free ASP.NET MVC Ecommerce Shopping Cart Solution: SmartStore.NET 2.0.2: SmartStore.NET 2.0.2 is primarily a maintenance release for version 2.0.0, which has been released on April 04 2014. It contains several improvements & important fixes. BugfixesIMPORTANT FIX: Memory leak leads to OutOfMemoryException in application after a while Installation fix: some varchar(MAX) columns get created as varchar(4000). Added a migration to fix the column specs. Installation fix: Setup fails with exception Value cannot be null. Parameter name: stream Bugfix for stock iss...Channel9's Absolute Beginner Series: Windows Phone 8.1: Entire source code for Windows Phone 8.1 Absolute Beginner Series.BIDS Helper: BIDS Helper 1.6.6: This BIDS Helper beta release brings support for SQL Server 2014 and SSDTBI for Visual Studio 2013. (Note that SSDTBI for Visual Studio 2013 is currently unavailable to download from Microsoft. We are releasing BIDS Helper support to help those who downloaded it before it became unavailable, and we will recheck BIDS Helper 2014 is compatible after SSDTBI becomes available to download again.) BIDS Helper 2014 Beta Limitations: SQL Server 2014 support for Biml is still in progress, so this bet...Windows Phone IsoStoreSpy (a cool WP8.1 + WP8 Isolated Storage Explorer): IsoStoreSpy WP8.1 3.0.0.0 (Win8 only): 3.0.0.0 + WP8.1 & WP8 device allowed + Local, Roaming or Temp directory Selector for WindowsRuntime apps + Version number in the title :)CS-Script for Notepad++ (C# intellisense and code execution): Release v1.0.24.0: ShortcutMapping panel now allows direct modification of the shortcuts. Custom updater dropped support for MSI installation but it still allows downloading of MSI http://www.csscript.net/npp/codeplex/non_msi_update.pngProDinner - ASP.NET MVC Sample (EF5, N-Tier, jQuery): 8.2: upgrade to mvc 5 upgrade to ASP.net MVC Awesome 4.0, EF 6.1, latest jcrop, Windsor Castle etc. ability to show/hide the dog using tinymce for the feedback page mobile friendly uiASP.net MVC Awesome - jQuery Ajax Helpers: 4.0: version 4.0 ========================== - added InitPopup, InitPopupForm helpers, open initialized popups using awe.open(name, params) - added Tag or Tags for all helpers, usable in mod code - added popup aweclose, aweresize events - popups have api accessible via .data('api'), with methods open, close and destroy - all popups have .awe-popup class - popups can be grouped using .Group(string), only 1 popup in the same group can exist at the same time - added awebeginload event for...SEToolbox: SEToolbox 01.028.008 Release 2: Fixes for drag-drop copying. Added ship joiner, to rejoin a broken ship! Installation of this version will replace older version.ScreenToGif: Release 1.0: What's new: • Small UI tweaks everywhere. • You can add Text, Subtitles and Title Frames. • Processing the gif now takes less time. • Languages: Spanish, Italian and Tamil added. • Single .exe multi language. • Takes less time to apply blur and pixelated efect. • Restart button. • Language picker. (If the user wants to select a diferent language than the system's) • "Encoding Finished" page with a link to open the file. • GreenScreen unchanged pixels to save kilobytes. • "Check for Updates" t...Touchmote: Touchmote 1.0 beta 11: Changes Support for multiple monitor setup Additional settings for analog sticks More reliable pairing Bug fixes and improvementsPowerShell App Deployment Toolkit: PowerShell App Deployment Toolkit v3.1.2: Added Get-IniValue / Set-IniValue functions. Replaces Get-IniContent / Set-IniContent which were a bit unwieldy. The new functions are much easier to use. Added -Value parameter to Get-RegistryKey so that a specific registry value can be retrieved instead of the entire Key as an object Fixed Test-Battery to work with machines that can have multiple batteries Fixed issue where BlockExecution would fail if a Custom Temp Path was specified in the config file Updated examples with latest ...Microsoft Script Analyzer: Microsoft Script Analyzer 1.1: The Script Analyzer scans your current PowerShell script code against some PowerShell best practice rules, and provide suggestions to improve the script quality and readability. By double-clicking the checking result, the relevant script code will be highlighted in the code editor. Script Analyzer result You can configure the Script Analyzer rules in the Settings window of Script Analyzer. Script Analyzer settings The current release includes 5 PowerShell best practice rules. Invoke-...Microsoft Script Browser: Script Browser 1.1: Script Browser for Windows PowerShell ISE was designed and developed in response to many IT Pros’ and MVPs’ feedback during the MVP Global Summit. It puts nearly 10K script examples at IT Pros fingertips when they write scripts to automate their IT tasks. Users can search, learn, download and manage scripts from within their scripting environment - PowerShell ISE - with just a few button clicks. It saves the time of switching back and forth between webpages and scripting environment, and also...New ProjectsAOP.Net: this project is used to implement AOP in .NetARTYKLES: Project articles ASP.NET Identity 2.0 Azure Table Storage: This project provides a high performance cloud solution for ASP.NET Identity 2.0 using Azure Table storage replacing the Entity Framework / MSSQL provider.Associativy Taxonomies Adapter: Administration module for the Associativy (http://associativy.com) Orchard graph platform.BancoSim: BancoSim inicioChaosKit: Chaos theory based time series analysis library, calculating Lyapunov and Hurst exponents and making iterated predictions.ElectrodomesticosAbr2014: Proyecto de ElectrodomesticosGPM: general privilege systemLNTest: LNTestLocal Electrodomésticos 001: Se tiene un local de electrodomésticos que tiene intensión de salir a online. MVC - Filtered TextBox: The project contains MVC Html helper methods for rendering a filtered text box that allows the user to enter only a given set of characters.MvcTrialer: A simple class for .NET 4 MVC to redirect pages if users exceeded a trial period date.NotificationsExtensions.Portable: Portable Class Library Version of the NotificationsExtensions NuGet Packages. Used to Create WinRT/Windows Phone Notification XML.OBD-II: Cross platform library for communicating with OBD-II adapters.Powershell Analyze Robocopy Logs and mail its results: It analyzes a path with Robocopy Log files. It'll create a summary file with information about all log files and it'll mail its results.Proyecto Electrodomesticos: proyecto electrodomesticosPrueba1: asdPVT Library: PVT library for calculating the thermodynamic properties of fluidQuanLyPhongMachThuY: Project serve for .NET CourcseRAMED: project that give some functionalities to ramed projects management like permissions and capabilities to make the management of this type of projects easierSimple Contacts: Simple Contacts Directory application built with ASP.NET MVC and Web API that perform basic CRUD (create, read, update, delete) operations.Stream oriented base64 encoder and decoder: Very simple implementation of stream oriented base64 encoder and decoder, which uses standard .NET Stream decorators. Super Casa de Electronica: no se q escribirTiny Deduplicator: Tiny Deduplicator is a file deduplicator which can scan for duplicate files, and allows the user to control which duplicates they are going to keep or recycle.webdemo: DemonstrationWindows Embedded Compact Edition 2013 File Transfer: A console app for transferring files using TCPIP between Windows Embedded Compact devices, and between them and the desktop. Compact 2013 and Desktop versions.Windows Tile Updater: An simple example of using the Microsoft Universal App to update a tile on the start screen. This was created to accompany a series of blog posts.WMI.NET: WMI.NET Demo Project form Win32 ClassesWumper Thumpers: The ultimate sweg

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• Managed Service Architectures Part I

  - by barryoreilly

  Instead of thinking about service oriented architecture, a concept that is continually defined, redefined, abused and mistreated, perhaps it is time to drop the acronym and consider what we actually need to get the job done.   ‘Pure’ SOA involves the modeling of an organisation’s processes, the so called ‘Top Down’ approach, followed by the implementation of these processes as services.     Another approach, more commonly seen in the wild, is the bottom up approach. This usually involves services that simply start popping up in the organization, and SOA in this case is often just an attempt to rein in these services. Such projects, although described as SOA projects for a variety of reasons, have clearly little relation to process driven architecture. Much has been written about these two approaches, with many deciding that a hybrid of both methods is needed to succeed with SOA.   These hybrid methods are a sensible compromise, but one gets the feeling that there is too much focus on ‘Succeeding with SOA’. Organisations who focus too much on bottom up development, or who waste too much time and money on top down approaches that don’t produce results, are often recommended to attempt an ‘agile’(Erl) or ‘middle-out’ (Microsoft) approach in order to succeed with SOA.  The problem with recommending this approach is that, in most cases, succeeding with SOA isn’t the aim of the project. If a project is started with the simple aim of ‘Succeeding with SOA’ then the reasons for the projects existence probably need to be questioned.   There are a number of things we can be sure of: ·         An organisation will have a number of disparate IT systems ·         Some of these systems will have redundant data and functionality ·         Integration will give considerable ROI ·         Integration will already be under way. ·         Services will already exist in the organisation ·         These services will be inconsistent in their implementation and in their governance   So there are three goals here: 1.       Alignment between the business and IT 2.     Integration of disparate systems 3.     Management of services.   2 and 3 are going to happen,  in fact they must happen if any degree of return is expected from the IT department. Ignoring 1 is considered a typical mistake in SOA implementations, as it ignores the business implications. However, the business implication of this approach is the money saved in more efficient IT processes. 2 and 3 are ongoing, and they will continue happening, even if a large project to produce a SOA metamodel is started. The result will then be an unstructured cackle of services, and a metamodel that is already going out of date. So we get stuck in and rebuild our services so that they match the metamodel, with the far reaching consequences that this will have on all our LOB systems are current. Lets imagine that this actually works ( how often do we rip and replace working software because it doesn't fit a certain pattern? Never -that's the point of integration), we will now be working with a metamodel that is out of date, and most likely incomplete if the organisation is large.      Accepting that an object can have more than one model over time, with perhaps more than one model being  at any given time will help us realise the limitations of the top down model. It is entirely normal , and perhaps necessary, for an organisation to be able to view an entity from different perspectives.   So, instead of trying to constantly force these goals in a straight line, why not let them happen in parallel, and manage the changes in each layer.     If  company A has chosen to model their business processes and create a business architecture, there will be a reason behind this. Often the aim is to make the business more flexible and able to cope with change, through alignment between the business and the IT department.   If company B’s IT department recognizes the problem of wild services springing up everywhere, and decides to do something about it, by designing a platform and processes for the introduction of services, is this not a valid approach?   With the hybrid approach, it is recommended that company A begin deploying services as quickly as possible. Based on models that are clearly incomplete, and which will therefore change rapidly and often in the near future. Natural business evolution will also mean that the models can be guaranteed to change in the not so near future. To ‘Succeed with SOA’ Company B needs to go back to the drawing board and start modeling processes and objects. So, in effect, we are telling business analysts to start developing code based on a model they are unsure of, and telling programmers to ignore the obvious and growing problems in their IT department and start drawing lines and boxes.     Could the problem be that there are two different problem domains? And the whole concept of SOA as it being described by clever salespeople today creates an example of oft dreaded ‘tight coupling’ between these two domains?   Could it be that we have taken two large problem areas, and bundled the solution together in order to create a magic bullet? And then convinced ourselves that the bullet actually exists?   Company A wants to have a closer relationship between the business and its IT department, in order to become a more flexible organization. Company B wants to decrease the maintenance costs of its IT infrastructure. If both companies focus on succeeding with SOA, then they aren’t focusing on their actual goals.   If Company A starts building services from incomplete models, without a gameplan, they will end up in the same situation as company B, with wild services. If company B focuses on modeling, they could easily end up with the same problems as company A.   Now we have two companies, who a short while ago had one problem each, that now have two problems each. This has happened because of a focus on ‘Succeeding with SOA’, rather than solving the problem at hand.   This is not to suggest that the two problem domains are unrelated, a strategy that encompasses both will obviously be good for the organization. But only if the organization realizes this and can develop such a strategy. This strategy cannot be bought in a box.       Anyone who has worked with SOA for a while will be used to analyzing the solutions to a problem and judging the solution’s level of coupling. If we have two applications that each perform separate functions, but need to communicate with each other, we create a integration layer between them, perhaps with a service, but we do all we can to reduce the dependency between the two systems. Using the same approach, we can separate the modeling (business architecture) and the service hosting (technical architecture).     The business architecture describes the processes and business objects in the business domain.   The technical architecture describes the hosting and management and implementation of services.   The glue that binds these together, the integration layer in our analogy, is the service contract, where the operations map the processes to their technical implementation, and the messages map business concepts to software objects in the implementation.   If we reduce the coupling between these layers, we should be able to allow developers to develop services, and business analysts to develop models, without the changes rippling through from one side to the other.   This would allow company A to carry on modeling, and company B to develop a service platform, each achieving their intended goal, without necessarily creating the problems seen in pure top down or bottom up approaches. Company B could then at a later date map their service infrastructure to a unified model, and company A could carry on modeling, insulating deployed services from changes in the ongoing modeling.   How do we do this?  The concept of service virtualization has been around for a while, and is instantly realizable in Microsoft’s Managed Services Engine. Here we can create a layer of virtual services, which represent the business analyst’s view, presenting uniform contracts to the outside world. These services can then transform and route messages to the actual service implementations. I like to think of the virtual services with their beautifully modeled interfaces as ‘SOA services’, and the implementations as simple integration ‘adapter’ services providing an interface to a technical implementation. The Managed Services Engine also provides policy based control over services, regardless of where they are deployed, simplifying handling of security, logging, exception handling etc.   This solves a big problem. The pressure to deliver services quickly is always there in projects. It is very important to quickly show value when implementing service architectures. There is also pressure to deliver quality, and you can’t easily do both at the same time. This approach allows quick delivery with quality increasing over time, allowing modeling and service development to occur in parallel and independent of each other. The link between business modeling and service implementation is not one that is obvious to many organizations, and requires a certain maturity to realize and drive forward. It is also completely possible that a company can benefit from one without the other, even if this approach is frowned upon today, there are many companies doing so and seeing ROI.   Of course there are disadvantages to this. The biggest one being the transformations necessary between the virtual interfaces and the service implementations. Bad choices in developing the services in the service implementation could mean that it is impossible to map the modeled processes to the implementation with redevelopment of the service. In many cases the architect will not have a choice here anyway, as proprietary systems are often delivered with predeveloped services. The alternative is to wait until the model is finished and then build the service according the model. However, if that approach worked we wouldn’t be having this discussion! And even when it does work, natural business evolution will mean that the two concepts (model and implementation) will immediately start to drift away from each other, so coupling them tightly together so that they are forever bound to the model that only applies at the time of the modeling work will not really achieve a great deal. Architecture is all about trade offs, and here a choice has to be made. The choice is between something will initially be of low quality but will work, or something that may well be impossible to achieve in most situations.         In conclusion, top-down is a natural approach for business analysts, and bottom-up  is a natural approach for developers. Instead of trying to force something on both that neither want, and which has not shown itself to be successful,  why not let them get on with their jobs, and let an enterprise architect coordinate the processes?

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• What's New in Database Lifecycle Management in Enterprise Manager 12c Release 3

  - by HariSrinivasan

  Enterprise Manager 12c Release 3 includes improvements and enhancements across every area of the product. This blog provides an overview of the new and enhanced features in the Database Lifecycle Management area. I will deep dive into specific features more in depth in subsequent posts. "What's New?"  In this release, we focused on four things: 1. Lifecycle Management Support for new Database12c - Pluggable Databases 2. Management of long running processes, such as a security patch cycle (Change Activity Planner) 3. Management of large number of systems by · Leveraging new framework capabilities for lifecycle operations, such as the new advanced ‘emcli’ script option · Refining features such as configuration search and compliance 4. Minor improvements and quality fixes to existing features · Rollback support for Single instance databases · Improved "OFFLINE" Patching experience · Faster collection of ORACLE_HOME configurations Lifecycle Management Support for new Database 12c - Pluggable Databases Database 12c introduces Pluggable Databases (PDBs), the brand new addition to help you achieve your consolidation goals. Pluggable databases offer unprecedented consolidation at database level and native lifecycle verbs for creating, plugging and unplugging the databases on a container database (CDB). Enterprise Manager can supplement the capabilities of pluggable databases by offering workflows for migrating, provisioning and cloning them using the software library and the deployment procedures. For example, Enterprise Manager can migrate an existing database to a PDB or clone a PDB by storing a versioned copy in the software library. One can also manage the planned downtime related to patching by  migrating the PDBs to a new CDB. While pluggable databases offer these exciting features, it can also pose configuration management and compliance challenges if not managed properly. Enterprise Manager features like inventory management, topology associations and configuration search can mitigate the sprawl of PDBs and also lock them to predefined golden standards using configuration comparison and compliance rules. Learn More ... Management of Long Running datacenter processes - Change Activity Planner (CAP) Currently, customers resort to cumbersome methods to create, execute, track and monitor change activities within their data center. Some customers use traditional tools such as spreadsheets, project planners and in-house custom built solutions. Customers often have weekly sync up meetings across stake holders to collect status and updates. Some of the change activities, for example the quarterly patch set update (PSU) patch rollouts are not single tasks but processes with multiple tasks. Some of those tasks are performed within Enterprise Manager Cloud Control (for example Patch) and some are performed outside of Enterprise Manager Cloud Control. These tasks often run for a longer period of time and involve multiple people or teams. Enterprise Manger Cloud Control supports core data center operations such as configuration management, compliance management, and automation. Enterprise Manager Cloud Control release 12.1.0.3 leverages these capabilities and introduces the Change Activity Planner (CAP). CAP provides the ability to plan, execute, and track change activities in real time. It covers the typical datacenter activities that are spread over a long period of time, across multiple people and multiple targets (even target types). Here are some examples of Change Activity Process in a datacenter: · Patching large environments (PSU/CPU Patching cycles) · Upgrading large number of database environments · Rolling out Compliance Rules · Database Consolidation to Exadata environments CAP provides user flows for Compliance Officers/Managers (incl. lead administrators) and Operators (DBAs and admins). Managers can create change activity plans for various projects, allocate resources, targets, and groups affected. Upon activation of the plan, tasks are created and automatically assigned to individual administrators based on target ownership. Administrators (DBAs) can identify their tasks and understand the context, schedules, and priorities. They can complete tasks using Enterprise Manager Cloud Control automation features such as patch plans (or in some cases outside Enterprise Manager). Upon completion, compliance is evaluated for validations and updates the status of the tasks and the plans. Learn More about CAP ...  Improved Configuration & Compliance Management of a large number of systems Improved Configuration Comparison:  Get to the configuration comparison results faster for simple ad-hoc comparisons. When performing a 1 to 1 comparison, Enterprise Manager will perform the comparison immediately and take the user directly to the results without having to wait for a job to be submitted and executed. Flattened system comparisons reduce comparison setup time and reduce complexity. In addition to the previously existing topological comparison, users now have an option to compare using a “flattened” methodology. Flattening means to remove duplicate target instances within the systems and remove the hierarchy of member targets. The result are much easier to spot differences particularly for specific use cases like comparing patch levels between complex systems like RAC and Fusion Apps. Improved Configuration Search & Advanced EMCLI Script option for Mass Automation Enterprise manager 12c introduces a new framework level capability to be able to script and stitch together multiple tasks using EMCLI. This powerful capability can be leveraged for lifecycle operations, especially when executing a task over a large number of targets. Specific usages of this include, retrieving a qualified list of targets using Configuration Search and then using the resultset for automation. Another example would be executing a patching operation and then re-executing on targets where it may have failed. This is complemented by other enhancements, such as a better usability for designing reusable configuration searches. IN EM 12c Rel 3, a simplified UI makes building adhoc searches even easier. Searching for missing patches is a common use of configuration search. This required the use of the advanced options which are now clearly defined and easy to use. Perform “Configuration Search” using the EMCLI. Users can find and execute Configuration Searches from the EMCLI which can be extremely useful for building sophisticated automation scripts. For an example, Run the Search named “Oracle Databases on Exadata” which finds all Database targets running on top of Exadata. Further filter the results by refining by options like name, host, etc.. emcli get_targets -config_search="Databases on Exadata" –target_name="exa%“ Use this in powerful mass automation operations using the new emcli script option. For example, to solve the use case of – Finding all DBs running on Exadata and housing E-Biz and Patch them. Create a Python script with emcli functions and invoke it in the new EMCLI script option shell. Invoke the script in the new EMCLI with script option directly: $<path to emcli>/emcli @myPSU_Patch.py Richer compliance content:  Now over 50 Oracle Provided Compliance Standards including new standards for Pluggable Database, Fusion Applications, Oracle Identity Manager, Oracle VM and Internet Directory. 9 Oracle provided Real Time Monitoring Standards containing over 900 Compliance Rules across 500 Facets. These new Real time Compliance Standards covers both Exadata Compute nodes and Linux servers. The result is increased Oracle software coverage and faster time to compliance monitoring on Exadata. Enhancements to Patch Management: Overhauled "OFFLINE" Patching experience: Simplified Patch uploads UI to improve the offline experience of patching. There is now a single step process to get the patches into software library. Customers often maintain local repositories of patches, sometimes called software depots, where they host the patches downloaded from My Oracle Support. In the past, you had to move these patches to your desktop then upload them to the Enterprise Manager's Software library through the Enterprise Manager Cloud Control user interface. You can now use the following EMCLI command to upload multiple patches directly from a remote location within the data center: $emcli upload_patches -location <Path to Patch directory> -from_host <HOSTNAME> The upload process filters all of the new patches, automatically selects the relevant metadata files from the location, and uploads the patches to software library. Other Improvements:  Patch rollback for single instance databases, new option in the Patch Plan to rollback the patches added to the patch plans. Upon execution, the procedure would rollback the patch and the SQL applied to the single instance Databases. Improved and faster configuration collection of Oracle Home targets can enable more reliable automation at higher level functions like Provisioning, Patching or Database as a Service. Just to recap, here is a list of database lifecycle management features:  * Red highlights mark – New or Enhanced in the Release 3. • Discovery, inventory tracking and reporting • Database provisioning including o Migration to Pluggable databases o Plugging and unplugging of pluggable databases o Gold image based cloning o Scaling of RAC nodes •Schema and data change management •End-to-end patch management in online and offline modes, including o Patch advisories in online (connected with My Oracle Support) and offline mode o Patch pre-deployment analysis, deployment and rollback (currently only for single instance databases) o Reporting • Upgrade planning and execution of the upgrade process • Configuration management including • Compliance management with out-of-box content • Change Activity Planner for planning, designing and tracking long running processes For more information on Enterprise Manager’s database lifecycle management capabilities, visit http://www.oracle.com/technetwork/oem/lifecycle-mgmt/index.html

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• Clean Code Development & Flexible work environment - MSCC 26.10.2013

  Finally, some spare time to summarize my impressions and experiences of the recent meetup of Mauritius Software Craftsmanship Community. I already posted my comment on the event and on our social media networks: Professional - It's getting better with our meetups and I really appreciated that 'seniors' and 'juniors' were present today. Despite running a little bit out of time it was really great to see more students coming to the gathering. This time we changed location for our Saturday meetup and it worked out very well. A big thank you to Ebene Accelerator, namely Mrs Poonum, for the ability to use their meeting rooms for our community get-together. Already some weeks ago I had a very pleasant conversation with her about the MSCC aims, 'mission' and how we organise things. Additionally, I think that an environment like the Ebene Accelerator is a good choice as it acts as an incubator for young developers and start-ups. Reactions from other craftsmen Before I put my thoughts about our recent meeting down, I'd like to mention and cross-link to some of the other craftsmen that were present: "MSCC meet up is a massive knowledge gaining strategies for students, future entrepreneurs, or for geeks all around. Knowledge sharing becomes a fun. For those who have not been able to made it do subscribe on our MSCC meet up group at meetup.com." -- Nitin on Learning is fun with #MSCC #Ebene Accelerator "We then talked about the IT industry in Mauritius, salary issues in various field like system administration, software development etc. We analysed the reasons why people tend to hop from one company to another. That was a fun debate." -- Ish on MSCC meetup - Gang of Geeks "Flexible Learning Environment was quite interesting since these lines struck cords : "You're not a secretary....9 to 5 shouldn't suit you"....This allowed reflection...deep reflection....especially regarding the local mindset...which should be changed in a way which would promote creativity rather than choking it till death..." -- Yannick on 2nd MSCC Monthly Meet-up And others on Facebook... ;-) Visual impressions are available on our Meetup event page. More first time attendees We great pleasure I noticed that we have once again more first time visitors. A quick overlook showed that we had a majority of UoM students in first, second or last year. Some of them are already participating in the UoM Computer Club or are nominated as members of the Microsoft Student Partner (MSP) programme. Personally, I really appreciate the fact that the MSCC is able to gather such a broad audience. And as I wrote initially, the MSCC is technology-agnostic; we want IT people from any segment of this business. Of course, students which are about to delve into the 'real world' of working are highly welcome, and I hope that they might get one or other glimpse of experience or advice from employees. Sticking to the schedule? No, not really... And honestly, it was a good choice to go a little bit of the beaten tracks. I mean, yes we have a 'rough' agenda of topics that we would like to talk about or having a presentation about. But we keep it 'agile'. Due to the high number of new faces, we initiated another quick round of introductions and I gave a really brief overview of the MSCC. Next, we started to reflect on the Clean Code Developer (CCD) - Red Grade which we introduced on the last meetup. Nirvan was the lucky one and he did a good job on summarizing the various abbreviations of the first level of being a CCD. Actually, more interesting, we exchanged experience about the principles and practices of Red Grade, and it was very informative to get to know that Yann actually 'interviewed' a couple of friends, other students, local guys working in IT companies as well as some IT friends from India in order to counter-check on what he learned first-hand about Clean Code. Currently, he is reading the book of Robert C. Martin on that topic and I'm looking forward to his review soon. More output generates more input What seems to be like a personal mantra is working out pretty well for me since the beginning of this year. Being more active on social media networks, writing more article on my blog, starting the Mauritius Software Craftsmanship Community, and contributing more to other online communities has helped me to receive more project requests, job offers and possibilities to expand my business at IOS Indian Ocean Software Ltd. Actually, it is not a coincidence that one of the questions new craftsmen should answer during registration asks about having a personal blog. Whether you are just curious about IT, right in the middle of your Computer Studies, or already working in software development or system administration since a while you should consider to advertise and market yourself online. Easiest way to resolve this are to have online profiles on professional social media networks like LinkedIn, Xing, Twitter, and Google+ (no Facebook should be considered for private only), and considering to have a personal blog. Why? -- Be yourself, be proud of your work, and let other people know that you're passionate about your profession. Trust me, this is going to open up opportunities you might not have dreamt about... Exchanging ideas about having a professional online presence - MSCC meetup on the 26th October 2013 Furthermore, consider to put your Curriculum Vitae online, too. There are quite a number of service providers like 1ClickCV, Stack Overflow Careers 2.0, etc. which give you the ability to have an up to date CV online. At least put it on your site, next to your personal blog. Similar to what you would be able to see on my site here. Cyber Island Mauritius - are we there? A couple of weeks ago I got a 'cold' message on LinkedIn from someone living in the U.S. asking about the circumstances and conditions of the IT world of Mauritius. He has a great business idea, venture capital and is currently looking for a team of software developers (mainly mobile - iOS) for a new startup here in Mauritius. Since then we exchanged quite some details through private messages and Skype conversations, and I suggested that it might be a good chance to join our meetup through a conference call and see for yourself about potential candidates. During approximately 30 to 40 minutes the brief idea of the new startup was presented - very promising state-of-the-art technology aspects and integration of various public APIs -, and we had a good Q&A session about it. Also thanks to the excellent bandwidth provided by the Ebene Accelerator the video conference between three parties went absolutely well. Clean Code Developer - Orange Grade Hahaha - nice one... Being at the Orange Tower at Ebene and then talking about an Orange Grade as CCD. Well, once again I provided an overview of the principles and practices in that rank of Clean Code, and similar to our last meetup we discussed on the various aspect of each principle, whether someone already got in touch with it during studies or work, and how it could affect their future view on their source code. Following are the principles and practices of Clean Code Developer - Orange Grade: CCD Orange Grade - Principles Single Level of Abstraction (SLA) Single Responsibility Principle (SRP) Separation of Concerns (SoC) Source Code conventions CCD Orange Grade - Practices Issue Tracking Automated Integration Tests Reading, Reading, Reading Reviews Especially the part on reading technical books got some extra attention. We quickly gathered our views on that and came up with a result that ranges between Zero (0) and up to Fifteen (15) book titles per year. Personally, I'm keeping my progress between Six (6) and Eight (8) titles per year, but at least One (1) per quarter of a year. Which is also connected to the fact that I'm participating in the O'Reilly Reader Review Program and have a another benefit to get access to free books only by writing and publishing a review afterwards. We also had a good exchange on the extended topic of 'Reviews' - which to my opinion is abnormal difficult here in Mauritius for various reasons. As far as I can tell from my experience working with Mauritian software developers, either as colleagues, employees or during consulting services there are unfortunately two dominant pattern on that topic: Keeping quiet Running away Honestly, I have no evidence about why these are the two 'solutions' on reviews but that's the situation that I had to face over the last couple of years. Sitting together and talking about problematic issues, tackling down root causes of de-motivational activities and working on general improvements doesn't seem to have a ground within the IT world of Mauritius. Are you a typist or a creative software craftsman? - MSCC meetup on the 26th October 2013 One very good example that we talked about was the fact of 'job hoppers' as you can easily observe it on someone's CV - those people change job every single year; for no obvious reason! Frankly speaking, I wouldn't even consider an IT person like to for an interview. As a company you're investing money and effort into the abilities of your employees. Hiring someone that won't stay for a longer period is out of question. And sorry to say, these kind of IT guys smell fishy about their capabilities and more likely to cause problems than actually produce productive results. One of the reasons why there is a probation period on an employment contract is to give you the liberty to leave as early as possible in case that you don't like your new position. Don't fool yourself or waste other people's time and money by hanging around a full year only to snatch off the bonus payment... Future outlook: Developer's Conference Even though it is not official yet I already mentioned it several times during our weekly Code & Coffee sessions. The MSCC is looking forward to be able to organise or to contribute to an upcoming IT event. Currently, the rough schedule is set for April 2014 but this mainly depends on availability of location(s), a decent time frame for preparations, and the underlying procedures with public bodies to have it approved and so on. As soon as the information about date and location has been fixed there will be a 'Call for Papers' period in order to attract local IT enthusiasts to apply for a session slot and talk about their field of work and their passion in IT. More to come for sure... My resume of the day It was a great gathering and I am very pleased about the fact that we had another 15 craftsmen (plus 2 businessmen on conference call plus 2 young apprentices) in the same room, talking about IT related topics and sharing their experience as employees and students. Personally, I really appreciated the feedback from the students about their current view on their future career, and I really hope that some of them are going to pursue their dreams. Start promoting yourself and it will happen... Looking forward to your blogs! And last but not least our numbers on Meetup and Facebook have been increased as a direct consequence of this meetup. Please, spread the word about the MSCC and get your friends and colleagues to join our official site. The higher the number of craftsmen we have the better chances we have t achieve something great! Thanks!

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• Are your personal insecurities screwing up your internal communications?

  - by Lucy Boyes

  I do some internal comms as part of my job. Quite a lot of it involves talking to people about stuff. I’m spending the next couple of weeks talking to lots of people about internal comms itself, because we haven’t done a lot of audience/user feedback gathering, and it turns out that if you talk to people about how they feel and what they think, you get some pretty interesting insights (and an idea of what to do next that isn’t just based on guesswork and generalising from self). Three things keep coming up from talking to people about what we suck at  in terms of internal comms. And, as far as I can tell, they’re all examples where personal insecurity on the part of the person doing the communicating makes the experience much worse for the people on the receiving end. 1. Spending time telling people how you’re going to do something, not what you’re doing and why Imagine you’ve got to give an update to a lot of people who don’t work in your area or department but do have an interest in what you’re doing (either because they want to know because they’re curious or because they need to know because it’s going to affect their work too). You don’t want to look bad at your job. You want to make them think you’ve got it covered – ideally because you do*. And you want to reassure them that there’s lots of exciting work going on in your area to make [insert thing of choice] happen to [insert thing of choice] so that [insert group of people] will be happy. That’s great! You’re doing a good job and you want to tell people about it. This is good comms stuff right here. However, you’re slightly afraid you might secretly be stupid or lazy or incompetent. And you’re exponentially more afraid that the people you’re talking to might think you’re stupid or lazy or incompetent. Or pointless. Or not-adding-value. Or whatever the thing that’s the worst possible thing to be in your company is. So you open by mentioning all the stuff you’re going to do, spending five minutes or so making sure that everyone knows that you’re DOING lots of STUFF. And the you talk for the rest of the time about HOW you’re going to do the stuff, because that way everyone will know that you’ve thought about this really hard and done tons of planning and had lots of great ideas about process and that you’ve got this one down. That’s the stuff you’ve got to say, right? To prove you’re not fundamentally worthless as a human being? Well, maybe. But probably not. See, the people who need to know how you’re going to do the stuff are the people doing the stuff. And those are the people in your area who you’ve (hopefully-please-for-the-love-of-everything-holy) already talked to in depth about how you’re going to do the thing (because else how could they help do it?). They are the only people who need to know the how**. It’s the difference between strategy and tactics. The people outside of your bubble of stuff-doing need to know the strategy – what it is that you’re doing, why, where you’re going with it, etc. The people on the ground with you need the strategy and the tactics, because else they won’t know how to do the stuff. But the outside people don’t really need the tactics at all. Don’t bother with the how unless your audience needs it. They probably don’t. It might make you feel better about yourself, but it’s much more likely that Bob and Jane are thinking about how long this meeting has gone on for already than how personally impressive and definitely-not-an-idiot you are for knowing how you’re going to do some work. Feeling marginally better about yourself (but, let’s face it, still insecure as heck) is not worth the cost, which in this case is the alienation of your audience. 2. Talking for too long about stuff This is kinda the same problem as the previous problem, only much less specific, and I’ve more or less covered why it’s bad already. Basic motivation: to make people think you’re not an idiot. What you do: talk for a very long time about what you’re doing so as to make it sound like you know what you’re doing and lots about it. What your audience wants: the shortest meaningful update. Some of this is a kill your darlings problem – the stuff you’re doing that seems really nifty to you seems really nifty to you, and thus you want to share it with everyone to show that you’re a smart person who thinks up nifty things to do. The downside to this is that it’s mostly only interesting to you – if other people don’t need to know, they likely also don’t care. Think about how you feel when someone is talking a lot to you about a lot of stuff that they’re doing which is at best tangentially interesting and/or relevant. You’re probably not thinking that they’re really smart and clearly know what they’re doing (unless they’re talking a lot and being really engaging about it, which is not the same as talking a lot). You’re probably thinking about something totally unrelated to the thing they’re talking about. Or the fact that you’re bored. You might even – and this is the opposite of what they’re hoping to achieve by talking a lot about stuff – be thinking they’re kind of an idiot. There’s another huge advantage to paring down what you’re trying to say to the barest possible points – it clarifies your thinking. The lightning talk format, as well as other formats which limit the time and/or number of slides you have to say a thing, are really good for doing this. It’s incredibly likely that your audience in this case (the people who need to know some things about your thing but not all the things about your thing) will get everything they need to know from five minutes of you talking about it, especially if trying to condense ALL THE THINGS into a five-minute talk has helped you get clear in your own mind what you’re doing, what you’re trying to say about what you’re doing and why you’re doing it. The bonus of this is that by being clear in your thoughts and in what you say, and in not taking up lots of people’s time to tell them stuff they don’t really need to know, you actually come across as much, much smarter than the person who talks for half an hour or more about things that are semi-relevant at best. 3. Waiting until you’ve got every detail sorted before announcing a big change to the people affected by it This is the worst crime on the list. It’s also human nature. Announcing uncertainty – that something important is going to happen (big reorganisation, product getting canned, etc.) but you’re not quite sure what or when or how yet – is scary. There are risks to it. Uncertainty makes people anxious. It might even paralyse them. You can’t run a business while you’re figuring out what to do if you’ve paralysed everyone with fear over what the future might bring. And you’re scared that they might think you’re not the right person to be in charge of [thing] if you don’t even know what you’re doing with it. Best not to say anything until you know exactly what’s going to happen and you can reassure them all, right? Nope. The people who are going to be affected by whatever it is that you don’t quite know all the details of yet aren’t stupid***. You wouldn’t have hired them if they were. They know something’s up because you’ve got your guilty face on and you keep pulling people into meeting rooms and looking vaguely worried. Here’s the deal: it’s a lot less stressful for everyone (including you) if you’re up front from the beginning. We took this approach during a recent company-wide reorganisation and got really positive feedback. People would much, much rather be told that something is going to happen but you’re not entirely sure what it is yet than have you wait until it’s all fixed up and then fait accompli the heck out of them. They will tell you this themselves if you ask them. And here’s why: by waiting until you know exactly what’s going on to communicate, you remove any agency that the people that the thing is going to happen to might otherwise have had. I know you’re scared that they might get scared – and that’s natural and kind of admirable – but it’s also patronising and infantilising. Ask someone whether they’d rather work on a project which has an openly uncertain future from the beginning, or one where everything’s great until it gets shut down with no forewarning, and very few people are going to tell you they’d prefer the latter. Uncertainty is humanising. It’s you admitting that you don’t have all the answers, which is great, because no one does. It allows you to be consultative – you can actually ask other people what they think and how they feel and what they’d like to do and what they think you should do, and they’ll thank you for it and feel listened to and respected as people and colleagues. Which is a really good reason to start talking to them about what’s going on as soon as you know something’s going on yourself. All of the above assumes you actually care about talking to the people who work with you and for you, and that you’d like to do the right thing by them. If that’s not the case, you can cheerfully disregard the advice here, but if it is, you might want to think about the ways above – and the inevitable countless other ways – that making internal communication about you and not about your audience could actually be doing the people you’re trying to communicate with a huge disservice. So take a deep breath and talk. For five minutes or so. About the important things. Not the other things. As soon as you possibly can. And you’ll be fine.   *Of course you do. You’re good at your job. Don’t worry. **This might not always be true, but it is most of the time. Other people who need to know the how will either be people who you’ve already identified as needing-to-know and thus part of the same set as the people in you’re area you’ve already discussed this with, or else they’ll ask you. But don’t bring this stuff up unless someone asks for it, because most of the people in the audience really don’t care and you’re wasting their time. ***I mean, they might be. But let’s give them the benefit of the doubt and assume they’re not.

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• Session Evaluations

  - by BuckWoody

  I do a lot of public speaking. I write, teach, present and communicate at many levels. I love to do those things. And I love to get better at them. And one of the ways you get better at something is to get feedback on how you did. That being said, I have to confess that I really despise the “evaluations” I get at most venues. From college to technical events to other locations, at Microsoft and points in between, I find these things to be just shy of damaging, and most certainly useless. And it’s not always your fault. Ouch. That seems harsh. But let me ask you one question – and be as honest as you can with the answer – think about it first: “What is the point of a session evaluation?” I’m not saying there isn’t one. In fact, I think there’s a really important reason for them. In my mind, it’s really this: To make the speaker / next session better. Now, if you look at that, you can see right away that most session evals don’t accomplish this goal – not even a little. No, the way that they are worded and the way you (and I) fill them out, it’s more like the implied goal is this: Tell us how you liked this speaker / session. The current ones are for you, not for the speaker or the next person. It’s a popularity contest. Don’t get me wrong. I want to you have a good time. I want you to learn. I want (desperately, oh, please oh please) for you to like me. But in fact, that’s probably not why you went to the session / took the class / read that post. No, you want to learn, and to learn for a particular reason. Remember, I’m talking about college classes, sessions and other class environments here, not a general public event. Most – OK, all – session evaluations make you answer the second goal, not the first. Let’s see how: First, they don’t ask you why you’re there. They don’t ask you if you’re even qualified to evaluate the session or speaker. They don’t ask you how to make it better or keep it great. They use odd numeric scales that are meaningless. For instance, can someone really tell me the difference between a 100-level session and a 200-level one? Between a 400-level and a 500? Is it “internals” (whatever that means) or detail, or length or code, or what? I once heard a great description: A 100-level session makes me say, “wow - I’m smart.” A 500-level session makes me say “wow – that presenter is smart.” And just what is the difference between a 6 and a 7 answer on this question: How well did the speaker know the material? 1  2  3  4  5  6  7  8  9  10 Oh. My. Gosh. How does that make the next session better, or the speaker? And what criteria did you use to answer? And is a “10” better than a “1” (not always clear, and various cultures answer this differently). When it’s all said and done, a speaker basically finds out one thing from the current session evals: “They liked me. They really really liked me.” Or, “Wow. I think I may need to schedule some counseling for the depression I’m about to go into.” You may not think that’s what the speaker hears, but trust me, they do. Those are the only two reactions to the current feedback sheets they get. Either they keep doing what they are doing, or they get their feelings hurt. They just can’t use the information provided to do better. Sorry, but there it is. Keep in mind I do want your feedback. I want to get better. I want you to get your money and time’s worth, probably as much as any speaker alive. But I want those evaluations to be accurate, specific and actionable. I want to know if you had a good time, sure, but I also want to know if I did the right things, and if not, if I can do something different or better. And so, for your consideration, here is the evaluation form I would LOVE for you to use. Feel free to copy it and mail it to me any time. I’m going to put some questions here, and then I’ll even include why they are there. Notice that the form asks you a subjective question right away, and then makes you explain why. That’s work on your part. Notice also that it separates the room and the coffee and the lights and the LiveMeeting from the presenter. So many presenters are faced with circumstances beyond their control, and yet are rated high or low personally on those things. This form helps tease those apart. It’s not numeric. Numbers are easier for the scoring committees but are useless for you and me. So I don’t have any numbers. We’re actually going to have to read these things, not put them in a machine. Hey, if you put in the work to write stuff down, the least we could do is take the time to read it. It’s not anonymous. If you’ve got something to say, say it, and own up to it. People are not “more honest” when they are anonymous, they are less honest. So put your name on it. In fact – this is radical – I posit that these evaluations should be publicly available. Forever. Just like replies to a blog post. Hey, if I’m an organizer, I would LOVE to be able to have access to specific, actionable information on the attendees and the speakers. So if you want mine to be public, go for it. I’ll take the good and the bad. Enjoy. ------------------------------------------------------------------------------------------------------------------------------------------- Session Evaluation – Date, Time, Location, Topic Thanks for giving us your time today. We know that’s valuable, and we hope you learned something you can use from the session. If you can answer these questions as completely as you can, it will help the next person who attends a session here. Your Name: What you do for a living: (We Need your background to evaluate your evaluation) How long you have been doing that: (Again, we need your background to evaluate your evaluation) Paste Session Description Here: (This is what I said I would talk about) Did you like the session?                     No        Meh        Yes (General subjective question – overall “feeling”. You’ll tell us why in a minute.)  Tell us about the venue. Temperature, lights, coffee, or the online sound, performance, anything other than the speaker and the material. (Helps the logistics to be better or as good for the next person) 1. What did you expect to learn in this session? (How did you interpret that extract – did you have expectations that I should work towards for the next person?) 2. Did you learn what you expected to learn? Why? Be very specific. (This is the most important question there is. It tells us how to make the session better for someone like you.) 3. If you were giving this presentation, would you have done anything differently? What? (Helps us to gauge you, the listener, and might give us a great idea on how to do something better. Thanks!) 4. What will you do with the information you got? (Every presenter wants you to learn, and learn something useful. This will help us do that as well or better)  

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• Cannot ping host stale ARP cache?

  - by gkchicago

  I am having a strange issue with a Debian (Lenny/Linux 2.6.26-2-amd64) that has been driving me nuts. On some machines within my network I can ping the host in question just fine, other times I have to manually hard-code the ARP ethernet address for the IP in order to establish connectivity. I've finally worked it down to somehow involving ARP. I just found how to fix it in a way that made it work but I'm looking for help explaining this issue and also I don't trust my fix to be permanent.. My thought process has been the following but I just can't make any sense out of it: Could it be the card? (Intel 82555 rev 4) Could it be because there are two network cards? (Default route is eth0) Could it be because of the network aliases? Lenny? AMD x86_64? Argh.. Thank you for any insight you might have // Ping doesn't go thru [gordon@ubuntu ~]$ ping 192.168.135.101 PING 192.168.135.101 (192.168.135.101) 56(84) bytes of data. --- 192.168.135.101 ping statistics --- 4 packets transmitted, 0 received, 100% packet loss, time 3014ms // Here's the ARP Table, sometimes the .151 address is good, sometimes it // also matches the Gateways MAC like .101 is doing right here. [gordon@ubuntu ~]$ cat /proc/net/arp IP address HW type Flags HW address Mask Device 192.168.135.15 0x1 0x2 00:0B:DB:2B:24:89 * eth0 192.168.135.151 0x1 0x2 00:0B:6A:3A:30:A6 * eth0 192.168.135.1 0x1 0x2 00:1A:A2:2D:2A:04 * eth0 192.168.135.101 0x1 0x2 00:1A:A2:2D:2A:04 * eth0 // Drop the bad arp table listing and set it manually based on /sbin/ifconfig [gordon@ubuntu ~]$ sudo arp -d 192.168.135.101 [gordon@ubuntu ~]$ sudo arp -s 192.168.135.101 00:0B:6A:3A:30:A6 // Ping starts going thru..?!? [gordon@ubuntu ~]$ ping 192.168.135.101 PING 192.168.135.101 (192.168.135.101) 56(84) bytes of data. 64 bytes from 192.168.135.101: icmp_seq=1 ttl=64 time=15.8 ms 64 bytes from 192.168.135.101: icmp_seq=2 ttl=64 time=15.9 ms 64 bytes from 192.168.135.101: icmp_seq=3 ttl=64 time=16.0 ms 64 bytes from 192.168.135.101: icmp_seq=4 ttl=64 time=15.9 ms --- 192.168.135.101 ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3012ms rtt min/avg/max/mdev = 15.836/15.943/16.064/0.121 ms The following is my network config on this. gordon@db01:~$ /sbin/ifconfig eth0 Link encap:Ethernet HWaddr 00:0b:6a:3a:30:a6 inet addr:192.168.135.151 Bcast:192.168.135.255 Mask:255.255.255.0 inet6 addr: fe80::20b:6aff:fe3a:30a6/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:15476725 errors:0 dropped:0 overruns:0 frame:0 TX packets:10030036 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:18565307359 (17.2 GiB) TX bytes:3412098075 (3.1 GiB) eth0:0 Link encap:Ethernet HWaddr 00:0b:6a:3a:30:a6 inet addr:192.168.135.150 Bcast:192.168.135.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 eth0:1 Link encap:Ethernet HWaddr 00:0b:6a:3a:30:a6 inet addr:192.168.135.101 Bcast:192.168.135.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 eth1 Link encap:Ethernet HWaddr 00:e0:81:2a:6e:d0 inet addr:10.10.62.1 Bcast:10.10.62.255 Mask:255.255.255.0 inet6 addr: fe80::2e0:81ff:fe2a:6ed0/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:10233315 errors:0 dropped:0 overruns:0 frame:0 TX packets:19400286 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1112500658 (1.0 GiB) TX bytes:27952809020 (26.0 GiB) Interrupt:24 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:387 errors:0 dropped:0 overruns:0 frame:0 TX packets:387 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:41314 (40.3 KiB) TX bytes:41314 (40.3 KiB) gordon@db01:~$ sudo mii-tool -v eth0 eth0: negotiated 100baseTx-FD, link ok product info: Intel 82555 rev 4 basic mode: autonegotiation enabled basic status: autonegotiation complete, link ok capabilities: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD advertising: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD flow-control link partner: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD gordon@db01:~$ sudo route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface localnet * 255.255.255.0 U 0 0 0 eth0 10.10.62.0 * 255.255.255.0 U 0 0 0 eth1 default 192.168.135.1 0.0.0.0 UG 0 0 0 eth0

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• Pfsense 2.1 OpenVPN can't reach servers on the LAN

  - by Lucas Kauffman

  I have a small network set up like this: I have a Pfsense for connecting my servers to the WAN, they are using NAT from the LAN - WAN. I have an OpenVPN server using TAP to allow remote workers to be put on the same LAN network as the servers. They connect through the WAN IP to the OVPN interface. The LAN interface also servers as the gateway for the servers to get internet connection and has an IP of 10.25.255.254 The OVPN Interface and the LAN interface are bridged in BR0 Server A has an IP of 10.25.255.1 and is able to connect the internet Client A is connecting through the VPN and is assigned an IP address on its TAP interface of 10.25.24.1 (I reserved a /24 within the 10.25.0.0/16 for VPN clients) Firewall currently allows any-any connection OVPN towards LAN and vice versa Currently when I connect, all routes seem fine on the client side: Destination Gateway Genmask Flags Metric Ref Use Iface 300.300.300.300 0.0.0.0 255.255.255.0 U 0 0 0 eth0 10.25.0.0 10.25.255.254 255.255.0.0 UG 0 0 0 tap0 10.25.0.0 0.0.0.0 255.255.0.0 U 0 0 0 tap0 0.0.0.0 300.300.300.300 0.0.0.0 UG 0 0 0 eth0 I can ping the LAN interface: root@server:# ping 10.25.255.254 PING 10.25.255.254 (10.25.255.254) 56(84) bytes of data. 64 bytes from 10.25.255.254: icmp_req=1 ttl=64 time=7.65 ms 64 bytes from 10.25.255.254: icmp_req=2 ttl=64 time=7.49 ms 64 bytes from 10.25.255.254: icmp_req=3 ttl=64 time=7.69 ms 64 bytes from 10.25.255.254: icmp_req=4 ttl=64 time=7.31 ms 64 bytes from 10.25.255.254: icmp_req=5 ttl=64 time=7.52 ms 64 bytes from 10.25.255.254: icmp_req=6 ttl=64 time=7.42 ms But I can't ping past the LAN interface: root@server:# ping 10.25.255.1 PING 10.25.255.1 (10.25.255.1) 56(84) bytes of data. From 10.25.255.254: icmp_seq=1 Redirect Host(New nexthop: 10.25.255.1) From 10.25.255.254: icmp_seq=2 Redirect Host(New nexthop: 10.25.255.1) I ran a tcpdump on my em1 interface (LAN interface which has the IP of 10.25.255.254) tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on em1, link-type EN10MB (Ethernet), capture size 96 bytes 08:21:13.449222 IP 10.25.24.1 > 10.25.255.1: ICMP echo request, id 23623, seq 10, length 64 08:21:13.458211 ARP, Request who-has 10.25.255.1 tell 10.25.24.1, length 28 08:21:14.450541 IP 10.25.24.1 > 10.25.255.1: ICMP echo request, id 23623, seq 11, length 64 08:21:14.458431 ARP, Request who-has 10.25.255.1 tell 10.25.24.1, length 28 08:21:15.451794 IP 10.25.24.1 > 10.25.255.1: ICMP echo request, id 23623, seq 12, length 64 08:21:15.458530 ARP, Request who-has 10.25.255.1 tell 10.25.24.1, length 28 08:21:16.453203 IP 10.25.24.1 > 10.25.255.1: ICMP echo request, id 23623, seq 13, length 64 So traffic is reaching the LAN interface, but it's not getting passed it. But no answer from the 10.25.255.1 host. I'm not sure what I'm missing.

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• Unable to Mange DNS via MMC

  - by IT Helpdesk Team Manager

  When trying to access the DNS service on Microsoft Windows Server 2003 (Build 3790) domain controller/schema master via the MMC DNS snap in or locally via the DNS MMC from Administrative tools I'm getting a red "X" through the icon for the DNS Server. The inability to access DNS management via MMC happens on all domain controllers as well. We've looked at items such as the DHCP client not being started, incorrect DNS setup ( the machine points at itself and another DC ), the DNS service not running ( it is and all DNS queries via NSLOOKUP work correctly ), dslint returns the correct information and functions as expected. There is the following entry in the DNS event log: The DNS server could not initialize the remote procedure call (RPC) service. If it is not running, start the RPC service or reboot the computer. The event data is the error code. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. 0000: 0000051b dnscmd fails with RPC server unavailable yet RPC is started: C:\Documents and Settings\Administrator.DOMAIN>dnscmd /Info Info query failed status = 1722 (0x000006ba) Command failed: RPC_S_SERVER_UNAVAILABLE 1722 (000006ba) DCDIAG /TEST:DNS /V /E produces the following errors: Warning: no DNS RPC connectivity (error or non Microsoft DNS server is running) [Error details: 1753 (Type: Win32 - Description: There are no more endpoints available from the endpoint mapper.)] Warning: no DNS RPC connectivity (error or non Microsoft DNS server is running) [Error details: 1722 (Type: Win32 - Description: The RPC server is unavailable.)] The DNS server could not initialize the remote procedure call (RPC) service. If it is not running, start the RPC service or reboot the computer. The event data is the error code. A DNS query for _ldap._tcp.dc._msdcs. returns the correct results. All domain and ADS related activities are working except that I can't manage my DNS via MMC or dnscmd. Any thoughts or solutions would be greatly appreciated. EDIT: Adding Registry export per request: Key Name: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Rpc Class Name: <NO CLASS> Last Write Time: 10/18/2012 - 2:29 PM Value 0 Name: DCOM Protocols Type: REG_MULTI_SZ Data: ncacn_ip_tcp Value 1 Name: UuidSequenceNumber Type: REG_DWORD Data: 0xb19bd0f Key Name: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Rpc\ClientProtocols Class Name: <NO CLASS> Last Write Time: 3/9/2007 - 12:11 PM Value 0 Name: ncacn_np Type: REG_SZ Data: rpcrt4.dll Value 1 Name: ncacn_ip_tcp Type: REG_SZ Data: rpcrt4.dll Value 2 Name: ncadg_ip_udp Type: REG_SZ Data: rpcrt4.dll Value 3 Name: ncacn_http Type: REG_SZ Data: rpcrt4.dll Value 4 Name: ncacn_at_dsp Type: REG_SZ Data: rpcrt4.dll Key Name: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Rpc\NameService Class Name: <NO CLASS> Last Write Time: 2/20/2006 - 4:48 PM Value 0 Name: DefaultSyntax Type: REG_SZ Data: 3 Value 1 Name: Endpoint Type: REG_SZ Data: \pipe\locator Value 2 Name: NetworkAddress Type: REG_SZ Data: \\. Value 3 Name: Protocol Type: REG_SZ Data: ncacn_np Value 4 Name: ServerNetworkAddress Type: REG_SZ Data: \\. Key Name: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Rpc\NetBios Class Name: <NO CLASS> Last Write Time: 2/20/2006 - 4:48 PM Key Name: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Rpc\RpcProxy Class Name: <NO CLASS> Last Write Time: 3/9/2007 - 12:11 PM Value 0 Name: Enabled Type: REG_DWORD Data: 0x1 Value 1 Name: ValidPorts Type: REG_SZ Data: pdc:100-5000 Key Name: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Rpc\SecurityService Class Name: <NO CLASS> Last Write Time: 2/20/2006 - 4:48 PM Value 0 Name: 9 Type: REG_SZ Data: secur32.dll Value 1 Name: 10 Type: REG_SZ Data: secur32.dll Value 2 Name: 14 Type: REG_SZ Data: schannel.dll Value 3 Name: 16 Type: REG_SZ Data: secur32.dll Value 4 Name: 1 Type: REG_SZ Data: secur32.dll Value 5 Name: 18 Type: REG_SZ Data: secur32.dll Value 6 Name: 68 Type: REG_SZ Data: netlogon.dll

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• Degraded RAID5 and no md superblock on one of remaining drive

  - by ark1214

  This is actually on a QNAP TS-509 NAS. The RAID is basically a Linux RAID. The NAS was configured with RAID 5 with 5 drives (/md0 with /dev/sd[abcde]3). At some point, /dev/sde failed and drive was replaced. While rebuilding (and not completed), the NAS rebooted itself and /dev/sdc dropped out of the array. Now the array can't start because essentially 2 drives have dropped out. I disconnected /dev/sde and hoped that /md0 can resume in degraded mode, but no luck.. Further investigation shows that /dev/sdc3 has no md superblock. The data should be good since the array was unable to assemble after /dev/sdc dropped off. All the searches I done showed how to reassemble the array assuming 1 bad drive. But I think I just need to restore the superblock on /dev/sdc3 and that should bring the array up to a degraded mode which will allow me to backup data and then proceed with rebuilding with adding /dev/sde. Any help would be greatly appreciated. mdstat does not show /dev/md0 # cat /proc/mdstat Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath] md5 : active raid1 sdd2[2](S) sdc2[3](S) sdb2[1] sda2[0] 530048 blocks [2/2] [UU] md13 : active raid1 sdd4[3] sdc4[2] sdb4[1] sda4[0] 458880 blocks [5/4] [UUUU_] bitmap: 40/57 pages [160KB], 4KB chunk md9 : active raid1 sdd1[3] sdc1[2] sdb1[1] sda1[0] 530048 blocks [5/4] [UUUU_] bitmap: 33/65 pages [132KB], 4KB chunk mdadm show /dev/md0 is still there # mdadm --examine --scan ARRAY /dev/md9 level=raid1 num-devices=5 UUID=271bf0f7:faf1f2c2:967631a4:3c0fa888 ARRAY /dev/md5 level=raid1 num-devices=2 UUID=0d75de26:0759d153:5524b8ea:86a3ee0d spares=2 ARRAY /dev/md0 level=raid5 num-devices=5 UUID=ce3e369b:4ff9ddd2:3639798a:e3889841 ARRAY /dev/md13 level=raid1 num-devices=5 UUID=7384c159:ea48a152:a1cdc8f2:c8d79a9c With /dev/sde removed, here is the mdadm examine output showing sdc3 has no md superblock # mdadm --examine /dev/sda3 /dev/sda3: Magic : a92b4efc Version : 00.90.00 UUID : ce3e369b:4ff9ddd2:3639798a:e3889841 Creation Time : Sat Dec 8 15:01:19 2012 Raid Level : raid5 Used Dev Size : 1463569600 (1395.77 GiB 1498.70 GB) Array Size : 5854278400 (5583.08 GiB 5994.78 GB) Raid Devices : 5 Total Devices : 4 Preferred Minor : 0 Update Time : Sat Dec 8 15:06:17 2012 State : active Active Devices : 4 Working Devices : 4 Failed Devices : 1 Spare Devices : 0 Checksum : d9e9ff0e - correct Events : 0.394 Layout : left-symmetric Chunk Size : 64K Number Major Minor RaidDevice State this 0 8 3 0 active sync /dev/sda3 0 0 8 3 0 active sync /dev/sda3 1 1 8 19 1 active sync /dev/sdb3 2 2 8 35 2 active sync /dev/sdc3 3 3 8 51 3 active sync /dev/sdd3 4 4 0 0 4 faulty removed [~] # mdadm --examine /dev/sdb3 /dev/sdb3: Magic : a92b4efc Version : 00.90.00 UUID : ce3e369b:4ff9ddd2:3639798a:e3889841 Creation Time : Sat Dec 8 15:01:19 2012 Raid Level : raid5 Used Dev Size : 1463569600 (1395.77 GiB 1498.70 GB) Array Size : 5854278400 (5583.08 GiB 5994.78 GB) Raid Devices : 5 Total Devices : 4 Preferred Minor : 0 Update Time : Sat Dec 8 15:06:17 2012 State : active Active Devices : 4 Working Devices : 4 Failed Devices : 1 Spare Devices : 0 Checksum : d9e9ff20 - correct Events : 0.394 Layout : left-symmetric Chunk Size : 64K Number Major Minor RaidDevice State this 1 8 19 1 active sync /dev/sdb3 0 0 8 3 0 active sync /dev/sda3 1 1 8 19 1 active sync /dev/sdb3 2 2 8 35 2 active sync /dev/sdc3 3 3 8 51 3 active sync /dev/sdd3 4 4 0 0 4 faulty removed [~] # mdadm --examine /dev/sdc3 mdadm: No md superblock detected on /dev/sdc3. [~] # mdadm --examine /dev/sdd3 /dev/sdd3: Magic : a92b4efc Version : 00.90.00 UUID : ce3e369b:4ff9ddd2:3639798a:e3889841 Creation Time : Sat Dec 8 15:01:19 2012 Raid Level : raid5 Used Dev Size : 1463569600 (1395.77 GiB 1498.70 GB) Array Size : 5854278400 (5583.08 GiB 5994.78 GB) Raid Devices : 5 Total Devices : 4 Preferred Minor : 0 Update Time : Sat Dec 8 15:06:17 2012 State : active Active Devices : 4 Working Devices : 4 Failed Devices : 1 Spare Devices : 0 Checksum : d9e9ff44 - correct Events : 0.394 Layout : left-symmetric Chunk Size : 64K Number Major Minor RaidDevice State this 3 8 51 3 active sync /dev/sdd3 0 0 8 3 0 active sync /dev/sda3 1 1 8 19 1 active sync /dev/sdb3 2 2 8 35 2 active sync /dev/sdc3 3 3 8 51 3 active sync /dev/sdd3 4 4 0 0 4 faulty removed fdisk output shows /dev/sdc3 partition is still there. [~] # fdisk -l Disk /dev/sdx: 128 MB, 128057344 bytes 8 heads, 32 sectors/track, 977 cylinders Units = cylinders of 256 * 512 = 131072 bytes Device Boot Start End Blocks Id System /dev/sdx1 1 8 1008 83 Linux /dev/sdx2 9 440 55296 83 Linux /dev/sdx3 441 872 55296 83 Linux /dev/sdx4 873 977 13440 5 Extended /dev/sdx5 873 913 5232 83 Linux /dev/sdx6 914 977 8176 83 Linux Disk /dev/sda: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 * 1 66 530113+ 83 Linux /dev/sda2 67 132 530145 82 Linux swap / Solaris /dev/sda3 133 182338 1463569695 83 Linux /dev/sda4 182339 182400 498015 83 Linux Disk /dev/sda4: 469 MB, 469893120 bytes 2 heads, 4 sectors/track, 114720 cylinders Units = cylinders of 8 * 512 = 4096 bytes Disk /dev/sda4 doesn't contain a valid partition table Disk /dev/sdb: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sdb1 * 1 66 530113+ 83 Linux /dev/sdb2 67 132 530145 82 Linux swap / Solaris /dev/sdb3 133 182338 1463569695 83 Linux /dev/sdb4 182339 182400 498015 83 Linux Disk /dev/sdc: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sdc1 1 66 530125 83 Linux /dev/sdc2 67 132 530142 83 Linux /dev/sdc3 133 182338 1463569693 83 Linux /dev/sdc4 182339 182400 498012 83 Linux Disk /dev/sdd: 2000.3 GB, 2000398934016 bytes 255 heads, 63 sectors/track, 243201 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sdd1 1 66 530125 83 Linux /dev/sdd2 67 132 530142 83 Linux /dev/sdd3 133 243138 1951945693 83 Linux /dev/sdd4 243139 243200 498012 83 Linux Disk /dev/md9: 542 MB, 542769152 bytes 2 heads, 4 sectors/track, 132512 cylinders Units = cylinders of 8 * 512 = 4096 bytes Disk /dev/md9 doesn't contain a valid partition table Disk /dev/md5: 542 MB, 542769152 bytes 2 heads, 4 sectors/track, 132512 cylinders Units = cylinders of 8 * 512 = 4096 bytes Disk /dev/md5 doesn't contain a valid partition table

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• C#: System.Collections.Concurrent.ConcurrentQueue vs. Queue

  - by James Michael Hare

  I love new toys, so of course when .NET 4.0 came out I felt like the proverbial kid in the candy store!  Now, some people get all excited about the IDE and it’s new features or about changes to WPF and Silver Light and yes, those are all very fine and grand.  But me, I get all excited about things that tend to affect my life on the backside of development.  That’s why when I heard there were going to be concurrent container implementations in the latest version of .NET I was salivating like Pavlov’s dog at the dinner bell. They seem so simple, really, that one could easily overlook them.  Essentially they are implementations of containers (many that mirror the generic collections, others are new) that have either been optimized with very efficient, limited, or no locking but are still completely thread safe -- and I just had to see what kind of an improvement that would translate into. Since part of my job as a solutions architect here where I work is to help design, develop, and maintain the systems that process tons of requests each second, the thought of extremely efficient thread-safe containers was extremely appealing.  Of course, they also rolled out a whole parallel development framework which I won’t get into in this post but will cover bits and pieces of as time goes by. This time, I was mainly curious as to how well these new concurrent containers would perform compared to areas in our code where we manually synchronize them using lock or some other mechanism.  So I set about to run a processing test with a series of producers and consumers that would be either processing a traditional System.Collections.Generic.Queue or a System.Collection.Concurrent.ConcurrentQueue. Now, I wanted to keep the code as common as possible to make sure that the only variance was the container, so I created a test Producer and a test Consumer.  The test Producer takes an Action<string> delegate which is responsible for taking a string and placing it on whichever queue we’re testing in a thread-safe manner: 1: internal class Producer 2: { 3: public int Iterations { get; set; } 4: public Action<string> ProduceDelegate { get; set; } 5: 6: public void Produce() 7: { 8: for (int i = 0; i < Iterations; i++) 9: { 10: ProduceDelegate(“Hello”); 11: } 12: } 13: } Then likewise, I created a consumer that took a Func<string> that would read from whichever queue we’re testing and return either the string if data exists or null if not.  Then, if the item doesn’t exist, it will do a 10 ms wait before testing again.  Once all the producers are done and join the main thread, a flag will be set in each of the consumers to tell them once the queue is empty they can shut down since no other data is coming: 1: internal class Consumer 2: { 3: public Func<string> ConsumeDelegate { get; set; } 4: public bool HaltWhenEmpty { get; set; } 5: 6: public void Consume() 7: { 8: bool processing = true; 9: 10: while (processing) 11: { 12: string result = ConsumeDelegate(); 13: 14: if(result == null) 15: { 16: if (HaltWhenEmpty) 17: { 18: processing = false; 19: } 20: else 21: { 22: Thread.Sleep(TimeSpan.FromMilliseconds(10)); 23: } 24: } 25: else 26: { 27: DoWork(); // do something non-trivial so consumers lag behind a bit 28: } 29: } 30: } 31: } Okay, now that we’ve done that, we can launch threads of varying numbers using lambdas for each different method of production/consumption.  First let's look at the lambdas for a typical System.Collections.Generics.Queue with locking: 1: // lambda for putting to typical Queue with locking... 2: var productionDelegate = s => 3: { 4: lock (_mutex) 5: { 6: _mutexQueue.Enqueue(s); 7: } 8: }; 9:  10: // and lambda for typical getting from Queue with locking... 11: var consumptionDelegate = () => 12: { 13: lock (_mutex) 14: { 15: if (_mutexQueue.Count > 0) 16: { 17: return _mutexQueue.Dequeue(); 18: } 19: } 20: return null; 21: }; Nothing new or interesting here.  Just typical locks on an internal object instance.  Now let's look at using a ConcurrentQueue from the System.Collections.Concurrent library: 1: // lambda for putting to a ConcurrentQueue, notice it needs no locking! 2: var productionDelegate = s => 3: { 4: _concurrentQueue.Enqueue(s); 5: }; 6:  7: // lambda for getting from a ConcurrentQueue, once again, no locking required. 8: var consumptionDelegate = () => 9: { 10: string s; 11: return _concurrentQueue.TryDequeue(out s) ? s : null; 12: }; So I pass each of these lambdas and the number of producer and consumers threads to launch and take a look at the timing results.  Basically I’m timing from the time all threads start and begin producing/consuming to the time that all threads rejoin.  I won't bore you with the test code, basically it just launches code that creates the producers and consumers and launches them in their own threads, then waits for them all to rejoin.  The following are the timings from the start of all threads to the Join() on all threads completing.  The producers create 10,000,000 items evenly between themselves and then when all producers are done they trigger the consumers to stop once the queue is empty. These are the results in milliseconds from the ordinary Queue with locking: 1: Consumers Producers 1 2 3 Time (ms) 2: ---------- ---------- ------ ------ ------ --------- 3: 1 1 4284 5153 4226 4554.33 4: 10 10 4044 3831 5010 4295.00 5: 100 100 5497 5378 5612 5495.67 6: 1000 1000 24234 25409 27160 25601.00 And the following are the results in milliseconds from the ConcurrentQueue with no locking necessary: 1: Consumers Producers 1 2 3 Time (ms) 2: ---------- ---------- ------ ------ ------ --------- 3: 1 1 3647 3643 3718 3669.33 4: 10 10 2311 2136 2142 2196.33 5: 100 100 2480 2416 2190 2362.00 6: 1000 1000 7289 6897 7061 7082.33 Note that even though obviously 2000 threads is quite extreme, the concurrent queue actually scales really well, whereas the traditional queue with simple locking scales much more poorly. I love the new concurrent collections, they look so much simpler without littering your code with the locking logic, and they perform much better.  All in all, a great new toy to add to your arsenal of multi-threaded processing!

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• SSAS 2008 R2– Little Gems

  - by ACALVETT

  I have spent the last few days working with SSAS 2008 R2 and noticed a few small enhancements which many people probably won’t notice but i will list them here and why they are important to me. New profiler events Commit: This is a new sub class event for “progress report end”. This represents the elapsed time taken for the server to commit your data. It is important because for the duration of this event a server level lock will be in place blocking all incoming connections and causing time out...(read more)

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• SQL SERVER – Developer Training Resources and Summary Roundup

  - by pinaldave

  It is always pleasure for any author when other renowned authors in the industry write about you. Earlier I wrote a five part blog series on Developer Training and I have received a phenomenal response to the series. I have received plenty of comments, questions and feedback. I thought it would be nice to sum up the whole series as well answer a few of the questions received. Quick Recap Developer Training - Importance and Significance - Part 1 In this part we discussed the importance of training in the real world. The most important and valuable resource any company is its employee. Employees who have been well-trained will be better at their jobs and produce a better product.  An employee who is well trained obviously knows more about their job and all the technical aspects. I have a very high opinion about training employees and it is the most important task. Developer Training – Employee Morals and Ethics – Part 2 In this part we discussed the most crucial components of training. Often employees are expecting the company to pay for their training and the company expresses no interest in training the employee. Quite often training expenses are the real issue for both the employee and employer. There are companies that pay for 100% of the expenses and there are employees who opt for training on their own expense during their personal time. Training is often looked at as vacation by employee and employers and we need to change this mind-set. One of the ways is to report back the learning to your manager and implement newly learned knowledge in day-to-day work. Developer Training – Difficult Questions and Alternative Perspective - Part 3 This part was the most difficult to write as I tried to address a few difficult questions and answers. Training is such a sensitive issue that many developers when not receiving chance for training think about leaving the organization. The manager often feels pressure to accommodate every single employee for training even though his training budget is limited. It is indeed the responsibility of the developer to get maximum advantage from the training. Training immediately helps organizations but stays as a part of an employee’s knowledge forever. Developer Training – Various Options for Developer Training – Part 4 In this part I tried to explore a few methods and options for training. The generic feedback I received on this blog post was short and I should have explored each of the subject of the training in details. I believe there are two big buckets of training 1) Instructor Lead Training and 2) Self Lead Training. The common element between both the methods is “learning material”. Learning material can be of any format – videos, books, paper notes or just a plain black board. Instructor-led training is a very effective mode but not possible every single time. During the course of the developer’s career, one has to learn lots of new technology and it is almost impossible to have a quality trainer available on that subject at that time. Books are most effective and proven methods, however, it always helps if someone explains the concepts of the book with a demonstration. In recent times I have started to believe in online trainings which leads to a hybrid experience. Online trainings take the best part of the books and the best part of the instructor-led training and gives effective training in a matter of hours. Developer Training – A Conclusive Summary- Part 5 In this part, I shared what I was continuously thinking about developer training. There is no better teacher than oneself. There is no better motivation than a personal desire to learn new technology. Honestly there is nothing more personal learning. That “change is the only constant” and “adapt & overcome” are the essential lessons of life. One cannot stop the learning and resist the change. In the IT industry “ego of knowing all” and the “resistance to change” are the most challenging issues. Once someone overcomes them, life is much easier. I believe that proper and appropriate high quality training can help to address the burning issues. Opinion of Friends I invited a few of my friends to express their opinion about developer training and here are their opinions. I am listing them here in the order of the blog post publishing date. Nakul Vachhrajani - Developer Trainings-Importance, Benefits, Tips and follow-up Nakul’s sums of many of the concepts which are complementary to my blog posts. Nakul addresses the burning question of developer training with different angles. I am personally very impressed by his following statement - “Being skilled does not mean having just a stack of certifications, but it also means having an understanding about the internals of the products that you are working on – and using that knowledge to improve the efficiency & productivity at the workplace in turn resulting in better products, better consulting abilities and a happier self.” Nakul also suggests the online training options of Pluralsight. Vinod Kumar - Training–a necessity or bonus Vinod Kumar comes up with excellent follow up on developer training. Vinod is known for his inspirational writing about SQL Server. Vinod starts with a story of a student who is extremely eager to learn the wisdom of life from a monk but the monk does not accept him as a disciple for a long time. The conversation between student and monk is indeed an essence of all learning. We all want to learn quickly and be successful but the most important thing in life is to have the right attitude towards learning and more so towards life. The blog post end with a very important thought about how to avoid the famous excuse – “I don’t have enough time.” Ritesh Shah - Training – useful or useless? Ritesh brings up very important concept related to training. Ritesh in his meticulous style explains why training is an important and lifelong process. Training must not stop at any age but should continue forever. The moment training stops, progress stops along with. Paras Doshi - Professional Development Resource Paras is known for his to–the-point writing, and has summarized the five part series very precisely. He read the five part series and created a digest summary of the blog post. If you are in a rush and have no time to read my five series – I suggest you read his blog post. Training Resources I am often asked what the best resources for learning new technology are. This is the most difficult question EVER. There are plenty of good training resources available. When it is about training our needs are different, our preference of learning is different and we all have an opinion. Additionally, we all are located in different geographic locations worldwide and there is no way one solution will fit all. However, let me list a few of the training resources which I have built so far and you can consume them if you find it relevant to your need. SQL Server Books SQL Server Interview Questions and Answers SQL Wait Stats SQL Programming Joes 2 Pros SQL Server Video Tutorials SQL Server Questions and Answers SQL Server Performance: Indexing Basics SQL Server Performance: Introduction to Query Tuning SQL in Sixty Seconds Series of Sixty Seconds Learning Video on YouTube Trust me worldwide web is very big and there are plenty of high quality learning materials available worldwide – trainer-led as well online. I suggest you explore various options and make the best choice for yourself. Remember, training is your personal journey and it should never stop. Are you ready? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Developer Training, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• New Cumulative Updates for SQL Server 2008 SP1 & R2!

  - by AaronBertrand

  Well, this is the first time in a long time that I've blogged about cumulative updates for two different versions of SQL Server on the same day. Yesterday Microsoft released a cumulative update for SQL Server 2008 SP1 (bringing you to 10.0.2775), and a corresponding cumulative update for SQL Server 2008 R2 RTM (bringing you from 10.50.1600 to 10.50.1702). You can read more about these updates here: Cumulative Update #1 for SQL Server 2008 R2 RTM ( KB #981355 ) Cumulative Update #8 for SQL Server...(read more)

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• Microsoft Tech-Ed North America 2010 - SQL Server Upgrade, 2000 - 2005 - 2008: Notes and Best Practi

  - by ssqa.net

  It is just a week to go for Tech-Ed North America 2010 in New Orleans, this time also I'm speaking at this conference on the subject - SQL Server Upgrade, 2000 - 2005 - 2008: Notes and Best Practices from the Field... more from here .. It is a coincedence that this is the 2nd time the same talk has been selected in Tech-Ed North America for the topic I have presented in SQLBits before....(read more)

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• Talks Submitted for Ann Arbor Day of .NET 2010

  - by PSteele

  Just submitted my session abstracts for Ann Arbor's Day of .NET 2010.   Getting up to speed with .NET 3.5 -- Just in time for 4.0! Yes, C# 4.0 is just around the corner.  But if you haven't had the chance to use C# 3.5 extensively, this session will start from the ground up with the new features of 3.5.  We'll assume everyone is coming from C# 2.0.  This session will show you the details of extension methods, partial methods and more.  We'll also show you how LINQ -- Language Integrated Query -- can help decrease your development time and increase your code's readability.  If time permits, we'll look at some .NET 4.0 features, but the goal is to get you up to speed on .NET 3.5.   Go Ahead and Mock Me! When testing specific parts of your application, there can be a lot of external dependencies required to make your tests work.  Writing fake or mock objects that act as stand-ins for the real dependencies can waste a lot of time.  This is where mocking frameworks come in.  In this session, Patrick Steele will introduce you to Rhino Mocks, a popular mocking framework for .NET.  You'll see how a mocking framework can make writing unit tests easier and leads to less brittle unit tests.   Inversion of Control: Who's got control and why is it being inverted? No doubt you've heard of "Inversion of Control".  If not, maybe you've heard the term "Dependency Injection"?  The two usually go hand-in-hand.  Inversion of Control (IoC) along with Dependency Injection (DI) helps simplify the connections and lifetime of all of the dependent objects in the software you write.  In this session, Patrick Steele will introduce you to the concepts of IoC and DI and will show you how to use a popular IoC container (Castle Windsor) to help simplify the way you build software and how your objects interact with each other. If you're interested in speaking, hurry up and get your submissions in!  The deadline is Monday, April 5th! Technorati Tags: .NET,Ann Arbor,Day of .NET

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• C#/.NET Little Wonders: The Concurrent Collections (1 of 3)

  - by James Michael Hare

  Once again we consider some of the lesser known classes and keywords of C#.  In the next few weeks, we will discuss the concurrent collections and how they have changed the face of concurrent programming. This week’s post will begin with a general introduction and discuss the ConcurrentStack<T> and ConcurrentQueue<T>.  Then in the following post we’ll discuss the ConcurrentDictionary<T> and ConcurrentBag<T>.  Finally, we shall close on the third post with a discussion of the BlockingCollection<T>. For more of the "Little Wonders" posts, see the index here. A brief history of collections In the beginning was the .NET 1.0 Framework.  And out of this framework emerged the System.Collections namespace, and it was good.  It contained all the basic things a growing programming language needs like the ArrayList and Hashtable collections.  The main problem, of course, with these original collections is that they held items of type object which means you had to be disciplined enough to use them correctly or you could end up with runtime errors if you got an object of a type you weren't expecting. Then came .NET 2.0 and generics and our world changed forever!  With generics the C# language finally got an equivalent of the very powerful C++ templates.  As such, the System.Collections.Generic was born and we got type-safe versions of all are favorite collections.  The List<T> succeeded the ArrayList and the Dictionary<TKey,TValue> succeeded the Hashtable and so on.  The new versions of the library were not only safer because they checked types at compile-time, in many cases they were more performant as well.  So much so that it's Microsoft's recommendation that the System.Collections original collections only be used for backwards compatibility. So we as developers came to know and love the generic collections and took them into our hearts and embraced them.  The problem is, thread safety in both the original collections and the generic collections can be problematic, for very different reasons. Now, if you are only doing single-threaded development you may not care – after all, no locking is required.  Even if you do have multiple threads, if a collection is “load-once, read-many” you don’t need to do anything to protect that container from multi-threaded access, as illustrated below: 1: public static class OrderTypeTranslator 2: { 3: // because this dictionary is loaded once before it is ever accessed, we don't need to synchronize 4: // multi-threaded read access 5: private static readonly Dictionary<string, char> _translator = new Dictionary<string, char> 6: { 7: {"New", 'N'}, 8: {"Update", 'U'}, 9: {"Cancel", 'X'} 10: }; 11:  12: // the only public interface into the dictionary is for reading, so inherently thread-safe 13: public static char? Translate(string orderType) 14: { 15: char charValue; 16: if (_translator.TryGetValue(orderType, out charValue)) 17: { 18: return charValue; 19: } 20:  21: return null; 22: } 23: } Unfortunately, most of our computer science problems cannot get by with just single-threaded applications or with multi-threading in a load-once manner.  Looking at  today's trends, it's clear to see that computers are not so much getting faster because of faster processor speeds -- we've nearly reached the limits we can push through with today's technologies -- but more because we're adding more cores to the boxes.  With this new hardware paradigm, it is even more important to use multi-threaded applications to take full advantage of parallel processing to achieve higher application speeds. So let's look at how to use collections in a thread-safe manner. Using historical collections in a concurrent fashion The early .NET collections (System.Collections) had a Synchronized() static method that could be used to wrap the early collections to make them completely thread-safe.  This paradigm was dropped in the generic collections (System.Collections.Generic) because having a synchronized wrapper resulted in atomic locks for all operations, which could prove overkill in many multithreading situations.  Thus the paradigm shifted to having the user of the collection specify their own locking, usually with an external object: 1: public class OrderAggregator 2: { 3: private static readonly Dictionary<string, List<Order>> _orders = new Dictionary<string, List<Order>>(); 4: private static readonly _orderLock = new object(); 5:  6: public void Add(string accountNumber, Order newOrder) 7: { 8: List<Order> ordersForAccount; 9:  10: // a complex operation like this should all be protected 11: lock (_orderLock) 12: { 13: if (!_orders.TryGetValue(accountNumber, out ordersForAccount)) 14: { 15: _orders.Add(accountNumber, ordersForAccount = new List<Order>()); 16: } 17:  18: ordersForAccount.Add(newOrder); 19: } 20: } 21: } Notice how we’re performing several operations on the dictionary under one lock.  With the Synchronized() static methods of the early collections, you wouldn’t be able to specify this level of locking (a more macro-level).  So in the generic collections, it was decided that if a user needed synchronization, they could implement their own locking scheme instead so that they could provide synchronization as needed. The need for better concurrent access to collections Here’s the problem: it’s relatively easy to write a collection that locks itself down completely for access, but anything more complex than that can be difficult and error-prone to write, and much less to make it perform efficiently!  For example, what if you have a Dictionary that has frequent reads but in-frequent updates?  Do you want to lock down the entire Dictionary for every access?  This would be overkill and would prevent concurrent reads.  In such cases you could use something like a ReaderWriterLockSlim which allows for multiple readers in a lock, and then once a writer grabs the lock it blocks all further readers until the writer is done (in a nutshell).  This is all very complex stuff to consider. Fortunately, this is where the Concurrent Collections come in.  The Parallel Computing Platform team at Microsoft went through great pains to determine how to make a set of concurrent collections that would have the best performance characteristics for general case multi-threaded use. Now, as in all things involving threading, you should always make sure you evaluate all your container options based on the particular usage scenario and the degree of parallelism you wish to acheive. This article should not be taken to understand that these collections are always supperior to the generic collections. Each fills a particular need for a particular situation. Understanding what each container is optimized for is key to the success of your application whether it be single-threaded or multi-threaded. General points to consider with the concurrent collections The MSDN points out that the concurrent collections all support the ICollection interface. However, since the collections are already synchronized, the IsSynchronized property always returns false, and SyncRoot always returns null.  Thus you should not attempt to use these properties for synchronization purposes. Note that since the concurrent collections also may have different operations than the traditional data structures you may be used to.  Now you may ask why they did this, but it was done out of necessity to keep operations safe and atomic.  For example, in order to do a Pop() on a stack you have to know the stack is non-empty, but between the time you check the stack’s IsEmpty property and then do the Pop() another thread may have come in and made the stack empty!  This is why some of the traditional operations have been changed to make them safe for concurrent use. In addition, some properties and methods in the concurrent collections achieve concurrency by creating a snapshot of the collection, which means that some operations that were traditionally O(1) may now be O(n) in the concurrent models.  I’ll try to point these out as we talk about each collection so you can be aware of any potential performance impacts.  Finally, all the concurrent containers are safe for enumeration even while being modified, but some of the containers support this in different ways (snapshot vs. dirty iteration).  Once again I’ll highlight how thread-safe enumeration works for each collection. ConcurrentStack<T>: The thread-safe LIFO container The ConcurrentStack<T> is the thread-safe counterpart to the System.Collections.Generic.Stack<T>, which as you may remember is your standard last-in-first-out container.  If you think of algorithms that favor stack usage (for example, depth-first searches of graphs and trees) then you can see how using a thread-safe stack would be of benefit. The ConcurrentStack<T> achieves thread-safe access by using System.Threading.Interlocked operations.  This means that the multi-threaded access to the stack requires no traditional locking and is very, very fast! For the most part, the ConcurrentStack<T> behaves like it’s Stack<T> counterpart with a few differences: Pop() was removed in favor of TryPop() Returns true if an item existed and was popped and false if empty. PushRange() and TryPopRange() were added Allows you to push multiple items and pop multiple items atomically. Count takes a snapshot of the stack and then counts the items. This means it is a O(n) operation, if you just want to check for an empty stack, call IsEmpty instead which is O(1). ToArray() and GetEnumerator() both also take snapshots. This means that iteration over a stack will give you a static view at the time of the call and will not reflect updates. Pushing on a ConcurrentStack<T> works just like you’d expect except for the aforementioned PushRange() method that was added to allow you to push a range of items concurrently. 1: var stack = new ConcurrentStack<string>(); 2:  3: // adding to stack is much the same as before 4: stack.Push("First"); 5:  6: // but you can also push multiple items in one atomic operation (no interleaves) 7: stack.PushRange(new [] { "Second", "Third", "Fourth" }); For looking at the top item of the stack (without removing it) the Peek() method has been removed in favor of a TryPeek().  This is because in order to do a peek the stack must be non-empty, but between the time you check for empty and the time you execute the peek the stack contents may have changed.  Thus the TryPeek() was created to be an atomic check for empty, and then peek if not empty: 1: // to look at top item of stack without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (stack.TryPeek(out item)) 5: { 6: Console.WriteLine("Top item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Stack was empty."); 11: } Finally, to remove items from the stack, we have the TryPop() for single, and TryPopRange() for multiple items.  Just like the TryPeek(), these operations replace Pop() since we need to ensure atomically that the stack is non-empty before we pop from it: 1: // to remove items, use TryPop or TryPopRange to get multiple items atomically (no interleaves) 2: if (stack.TryPop(out item)) 3: { 4: Console.WriteLine("Popped " + item); 5: } 6:  7: // TryPopRange will only pop up to the number of spaces in the array, the actual number popped is returned. 8: var poppedItems = new string[2]; 9: int numPopped = stack.TryPopRange(poppedItems); 10:  11: foreach (var theItem in poppedItems.Take(numPopped)) 12: { 13: Console.WriteLine("Popped " + theItem); 14: } Finally, note that as stated before, GetEnumerator() and ToArray() gets a snapshot of the data at the time of the call.  That means if you are enumerating the stack you will get a snapshot of the stack at the time of the call.  This is illustrated below: 1: var stack = new ConcurrentStack<string>(); 2:  3: // adding to stack is much the same as before 4: stack.Push("First"); 5:  6: var results = stack.GetEnumerator(); 7:  8: // but you can also push multiple items in one atomic operation (no interleaves) 9: stack.PushRange(new [] { "Second", "Third", "Fourth" }); 10:  11: while(results.MoveNext()) 12: { 13: Console.WriteLine("Stack only has: " + results.Current); 14: } The only item that will be printed out in the above code is "First" because the snapshot was taken before the other items were added. This may sound like an issue, but it’s really for safety and is more correct.  You don’t want to enumerate a stack and have half a view of the stack before an update and half a view of the stack after an update, after all.  In addition, note that this is still thread-safe, whereas iterating through a non-concurrent collection while updating it in the old collections would cause an exception. ConcurrentQueue<T>: The thread-safe FIFO container The ConcurrentQueue<T> is the thread-safe counterpart of the System.Collections.Generic.Queue<T> class.  The concurrent queue uses an underlying list of small arrays and lock-free System.Threading.Interlocked operations on the head and tail arrays.  Once again, this allows us to do thread-safe operations without the need for heavy locks! The ConcurrentQueue<T> (like the ConcurrentStack<T>) has some departures from the non-concurrent counterpart.  Most notably: Dequeue() was removed in favor of TryDequeue(). Returns true if an item existed and was dequeued and false if empty. Count does not take a snapshot It subtracts the head and tail index to get the count.  This results overall in a O(1) complexity which is quite good.  It’s still recommended, however, that for empty checks you call IsEmpty instead of comparing Count to zero. ToArray() and GetEnumerator() both take snapshots. This means that iteration over a queue will give you a static view at the time of the call and will not reflect updates. The Enqueue() method on the ConcurrentQueue<T> works much the same as the generic Queue<T>: 1: var queue = new ConcurrentQueue<string>(); 2:  3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5: queue.Enqueue("Second"); 6: queue.Enqueue("Third"); For front item access, the TryPeek() method must be used to attempt to see the first item if the queue.  There is no Peek() method since, as you’ll remember, we can only peek on a non-empty queue, so we must have an atomic TryPeek() that checks for empty and then returns the first item if the queue is non-empty. 1: // to look at first item in queue without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (queue.TryPeek(out item)) 5: { 6: Console.WriteLine("First item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Queue was empty."); 11: } Then, to remove items you use TryDequeue().  Once again this is for the same reason we have TryPeek() and not Peek(): 1: // to remove items, use TryDequeue. If queue is empty returns false. 2: if (queue.TryDequeue(out item)) 3: { 4: Console.WriteLine("Dequeued first item " + item); 5: } Just like the concurrent stack, the ConcurrentQueue<T> takes a snapshot when you call ToArray() or GetEnumerator() which means that subsequent updates to the queue will not be seen when you iterate over the results.  Thus once again the code below will only show the first item, since the other items were added after the snapshot. 1: var queue = new ConcurrentQueue<string>(); 2:  3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5:  6: var iterator = queue.GetEnumerator(); 7:  8: queue.Enqueue("Second"); 9: queue.Enqueue("Third"); 10:  11: // only shows First 12: while (iterator.MoveNext()) 13: { 14: Console.WriteLine("Dequeued item " + iterator.Current); 15: } Using collections concurrently You’ll notice in the examples above I stuck to using single-threaded examples so as to make them deterministic and the results obvious.  Of course, if we used these collections in a truly multi-threaded way the results would be less deterministic, but would still be thread-safe and with no locking on your part required! For example, say you have an order processor that takes an IEnumerable<Order> and handles each other in a multi-threaded fashion, then groups the responses together in a concurrent collection for aggregation.  This can be done easily with the TPL’s Parallel.ForEach(): 1: public static IEnumerable<OrderResult> ProcessOrders(IEnumerable<Order> orderList) 2: { 3: var proxy = new OrderProxy(); 4: var results = new ConcurrentQueue<OrderResult>(); 5:  6: // notice that we can process all these in parallel and put the results 7: // into our concurrent collection without needing any external locking! 8: Parallel.ForEach(orderList, 9: order => 10: { 11: var result = proxy.PlaceOrder(order); 12:  13: results.Enqueue(result); 14: }); 15:  16: return results; 17: } Summary Obviously, if you do not need multi-threaded safety, you don’t need to use these collections, but when you do need multi-threaded collections these are just the ticket! The plethora of features (I always think of the movie The Three Amigos when I say plethora) built into these containers and the amazing way they acheive thread-safe access in an efficient manner is wonderful to behold. Stay tuned next week where we’ll continue our discussion with the ConcurrentBag<T> and the ConcurrentDictionary<TKey,TValue>. For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this wonderful whitepaper by the Microsoft Parallel Computing Platform team here.   Tweet Technorati Tags: C#,.NET,Concurrent Collections,Collections,Multi-Threading,Little Wonders,BlackRabbitCoder,James Michael Hare

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• Sorting a ListView in WPF – Part II

  - by marianor

  Some time ago I wrote a post about how to sort a ListView by clicking on the header of the column. The problem with that solution was that you needed to implement it each time and you have to define an explicit header for each column. As a more general solution I use attached properties to extend the ListView and GridViewColumn . The first attached property is tied to the ListView itself, and it indicates that the control supports sorting. This property attach or detach to the Click event of the...(read more)

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• SQL SERVER – 4 Tips for ETL Software IDE Developers

  - by pinaldave

  In a previous blog, I introduced the notion of Semantic Types. To an end-user, a seamlessly integrated semantic typing engine significantly increases the ease of use of an ETL IDE (integrated development environment, or developer studio). This led me to think about other ease-of-use issues I have encountered while building ETL applications. When I get stumped while programming, I find myself asking the variations on these questions: “How do I…?” “Now what?” “Why isn’t this working?” “Why do I have to redo the work I just did?” It seems to me that a good ETL IDE will anticipate these questions and seek to answer them before they are even asked. So here are my tips to help software vendors build developer IDEs that actually make development easier. How do I…? While developing an ETL application, have you ever asked yourself: “How do I set up the connection to my SQL Server database?”,“How do I import my table definitions from Access?”, etc. An easy answer might be “read the manual” but sometimes product manuals are not robust or easily accessible. So, integrating robust how-to instructions directly into your ETLstudio would help users get the information they need at the time they need it. Now what? IDEs in general know where you last clicked or performed an action using an input device such as a keyboard; so they should be able to reasonably predict the design context you are in and suggest the next steps accordingly. Context-sensitive suggestions based on the state of the user’s work will help users move forward in ETL application development. Why isn’t this working? Or why do I have to wait till I compile to be told about a critical design issue? If an ETL IDE is smart enough to signal to users what in their design structures is left to be completed or has been completed incorrectly, then the developer can spend much less time in the designàcompileàerror-correct loop. Just-in-time validation helps users detect and correct programming errors earlier in the ETL development life cycle. Why do I have to redo the work I just did? In ETL development, schemas, transformation rules, connectivity objects, etc., can be reused in various situations. Using mouse-clicks to build and manage libraries of reusable design objects implies that the application development effort should decrease over time and as the library acquires more objects. I met a great company at SQL Pass that is trying to address many of these usability issues. Check them out at www.expressor-software.com. What other ease-of-use suggestions do you have for ETL software vendors? Please post your valuable comments. ?Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Best Practices, Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: ETL

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• Visual Studio 2010 Launch April 12 Las Vegas

  - by Dave Campbell

  I'm going to be in 'Vegas for the Launch on Monday, I'm not sure what time I'm getting in on Sunday, but I'm staying over Monday night as well, so if you're going to be around in that time-frame, send me an email! Bummer to not be there for Silverlight on Tuesday, but hey... watching Scott Guthrie is always worth the drive :)

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