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  • How do you go from a so so programmer to a great one? [closed]

    - by Cervo
    How do you go from being an okay programmer to being able to write maintainable clean code? For example David Hansson was writing Basecamp when in the process he created Rails as part of writing Basecamp in a clean/maintainable way. But how do you know when there is value in a side project like that? I have a bachelors in computer science, and I am about to get a masters and I will say that colleges teach you to write code to solve problems, not neatly or anything. Basically you think of a problem, come up with a solution, and write it down...not necessarily the most maintainable way in the world. Also my first job was in a startup, and now my third is in a small team in a large company where the attitude was/is get it done yesterday (also most of my jobs are mainly database development with SQL with a few ASP.NET web pages/.NET apps on the side). So of course cut/paste is more favored than making things more cleanly. And they would rather have something yesterday even if you have to rewrite it next month rather than to have something in a week that lasts for a year. Also spaghetti code turns up all over the place, and it takes very smart people to write/understand/maintain spaghetti code...However it would be better to do things so simple/clean that even a caveman/woman could do maintenance. Also I get very bored/unmotivated having to go modify the same things cut/pasted in a few locations. Is this the type of skill that you need to learn by working with a serious software organization that has an emphasis on maintenance and maybe even an architect who designs a system architecture and reviews code? Could you really learn it by volunteering on an open source project (it seems to me that a full time programmer job is way more practice than a few hours a week on an open source project)? Is there some course where you can learn this? I can attest that graduate school and undergraduate school do not really emphasize clean software at all. They just teach the structures/algorithms and then send you off into the world to solve problems. Overall I think the first thing is learning to write clean/maintainable code within the bounds of the project in order to become a good programmer. Then the next thing is learning when you need to do a side project (like a framework) to make things more maintainable/clean even while you still deliver things for the deadline in order to become a great programmer. For example, you are making an SQL report and someone gives you 100 calculations for individual columns. At what point does it make sense to construct a domain specific language to encode the rules in simply and then generate all the SQL as opposed to cut/pasting the query from the table a bunch of times and then adjusting each query to do the appropriate calculations. This is the type of thing I would say a great programmer would know. He/she would maybe even know ways to avoid the domain specific language and to still do all the calculations without creating an unmaintainable mess or a ton of repetitive code to cut/paste everywhere.

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  • Does anyone really understand how HFSC scheduling in Linux/BSD works?

    - by Mecki
    I read the original SIGCOMM '97 PostScript paper about HFSC, it is very technically, but I understand the basic concept. Instead of giving a linear service curve (as with pretty much every other scheduling algorithm), you can specify a convex or concave service curve and thus it is possible to decouple bandwidth and delay. However, even though this paper mentions to kind of scheduling algorithms being used (real-time and link-share), it always only mentions ONE curve per scheduling class (the decoupling is done by specifying this curve, only one curve is needed for that). Now HFSC has been implemented for BSD (OpenBSD, FreeBSD, etc.) using the ALTQ scheduling framework and it has been implemented Linux using the TC scheduling framework (part of iproute2). Both implementations added two additional service curves, that were NOT in the original paper! A real-time service curve and an upper-limit service curve. Again, please note that the original paper mentions two scheduling algorithms (real-time and link-share), but in that paper both work with one single service curve. There never have been two independent service curves for either one as you currently find in BSD and Linux. Even worse, some version of ALTQ seems to add an additional queue priority to HSFC (there is no such thing as priority in the original paper either). I found several BSD HowTo's mentioning this priority setting (even though the man page of the latest ALTQ release knows no such parameter for HSFC, so officially it does not even exist). This all makes the HFSC scheduling even more complex than the algorithm described in the original paper and there are tons of tutorials on the Internet that often contradict each other, one claiming the opposite of the other one. This is probably the main reason why nobody really seems to understand how HFSC scheduling really works. Before I can ask my questions, we need a sample setup of some kind. I'll use a very simple one as seen in the image below: Here are some questions I cannot answer because the tutorials contradict each other: What for do I need a real-time curve at all? Assuming A1, A2, B1, B2 are all 128 kbit/s link-share (no real-time curve for either one), then each of those will get 128 kbit/s if the root has 512 kbit/s to distribute (and A and B are both 256 kbit/s of course), right? Why would I additionally give A1 and B1 a real-time curve with 128 kbit/s? What would this be good for? To give those two a higher priority? According to original paper I can give them a higher priority by using a curve, that's what HFSC is all about after all. By giving both classes a curve of [256kbit/s 20ms 128kbit/s] both have twice the priority than A2 and B2 automatically (still only getting 128 kbit/s on average) Does the real-time bandwidth count towards the link-share bandwidth? E.g. if A1 and B1 both only have 64kbit/s real-time and 64kbit/s link-share bandwidth, does that mean once they are served 64kbit/s via real-time, their link-share requirement is satisfied as well (they might get excess bandwidth, but lets ignore that for a second) or does that mean they get another 64 kbit/s via link-share? So does each class has a bandwidth "requirement" of real-time plus link-share? Or does a class only have a higher requirement than the real-time curve if the link-share curve is higher than the real-time curve (current link-share requirement equals specified link-share requirement minus real-time bandwidth already provided to this class)? Is upper limit curve applied to real-time as well, only to link-share, or maybe to both? Some tutorials say one way, some say the other way. Some even claim upper-limit is the maximum for real-time bandwidth + link-share bandwidth? What is the truth? Assuming A2 and B2 are both 128 kbit/s, does it make any difference if A1 and B1 are 128 kbit/s link-share only, or 64 kbit/s real-time and 128 kbit/s link-share, and if so, what difference? If I use the seperate real-time curve to increase priorities of classes, why would I need "curves" at all? Why is not real-time a flat value and link-share also a flat value? Why are both curves? The need for curves is clear in the original paper, because there is only one attribute of that kind per class. But now, having three attributes (real-time, link-share, and upper-limit) what for do I still need curves on each one? Why would I want the curves shape (not average bandwidth, but their slopes) to be different for real-time and link-share traffic? According to the little documentation available, real-time curve values are totally ignored for inner classes (class A and B), they are only applied to leaf classes (A1, A2, B1, B2). If that is true, why does the ALTQ HFSC sample configuration (search for 3.3 Sample configuration) set real-time curves on inner classes and claims that those set the guaranteed rate of those inner classes? Isn't that completely pointless? (note: pshare sets the link-share curve in ALTQ and grate the real-time curve; you can see this in the paragraph above the sample configuration). Some tutorials say the sum of all real-time curves may not be higher than 80% of the line speed, others say it must not be higher than 70% of the line speed. Which one is right or are they maybe both wrong? One tutorial said you shall forget all the theory. No matter how things really work (schedulers and bandwidth distribution), imagine the three curves according to the following "simplified mind model": real-time is the guaranteed bandwidth that this class will always get. link-share is the bandwidth that this class wants to become fully satisfied, but satisfaction cannot be guaranteed. In case there is excess bandwidth, the class might even get offered more bandwidth than necessary to become satisfied, but it may never use more than upper-limit says. For all this to work, the sum of all real-time bandwidths may not be above xx% of the line speed (see question above, the percentage varies). Question: Is this more or less accurate or a total misunderstanding of HSFC? And if assumption above is really accurate, where is prioritization in that model? E.g. every class might have a real-time bandwidth (guaranteed), a link-share bandwidth (not guaranteed) and an maybe an upper-limit, but still some classes have higher priority needs than other classes. In that case I must still prioritize somehow, even among real-time traffic of those classes. Would I prioritize by the slope of the curves? And if so, which curve? The real-time curve? The link-share curve? The upper-limit curve? All of them? Would I give all of them the same slope or each a different one and how to find out the right slope? I still haven't lost hope that there exists at least a hand full of people in this world that really understood HFSC and are able to answer all these questions accurately. And doing so without contradicting each other in the answers would be really nice ;-)

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  • Does anyone really understand how HFSC scheduling in Linux/BSD works?

    - by Mecki
    I read the original SIGCOMM '97 PostScript paper about HFSC, it is very technically, but I understand the basic concept. Instead of giving a linear service curve (as with pretty much every other scheduling algorithm), you can specify a convex or concave service curve and thus it is possible to decouple bandwidth and delay. However, even though this paper mentions to kind of scheduling algorithms being used (real-time and link-share), it always only mentions ONE curve per scheduling class (the decoupling is done by specifying this curve, only one curve is needed for that). Now HFSC has been implemented for BSD (OpenBSD, FreeBSD, etc.) using the ALTQ scheduling framework and it has been implemented Linux using the TC scheduling framework (part of iproute2). Both implementations added two additional service curves, that were NOT in the original paper! A real-time service curve and an upper-limit service curve. Again, please note that the original paper mentions two scheduling algorithms (real-time and link-share), but in that paper both work with one single service curve. There never have been two independent service curves for either one as you currently find in BSD and Linux. Even worse, some version of ALTQ seems to add an additional queue priority to HSFC (there is no such thing as priority in the original paper either). I found several BSD HowTo's mentioning this priority setting (even though the man page of the latest ALTQ release knows no such parameter for HSFC, so officially it does not even exist). This all makes the HFSC scheduling even more complex than the algorithm described in the original paper and there are tons of tutorials on the Internet that often contradict each other, one claiming the opposite of the other one. This is probably the main reason why nobody really seems to understand how HFSC scheduling really works. Before I can ask my questions, we need a sample setup of some kind. I'll use a very simple one as seen in the image below: Here are some questions I cannot answer because the tutorials contradict each other: What for do I need a real-time curve at all? Assuming A1, A2, B1, B2 are all 128 kbit/s link-share (no real-time curve for either one), then each of those will get 128 kbit/s if the root has 512 kbit/s to distribute (and A and B are both 256 kbit/s of course), right? Why would I additionally give A1 and B1 a real-time curve with 128 kbit/s? What would this be good for? To give those two a higher priority? According to original paper I can give them a higher priority by using a curve, that's what HFSC is all about after all. By giving both classes a curve of [256kbit/s 20ms 128kbit/s] both have twice the priority than A2 and B2 automatically (still only getting 128 kbit/s on average) Does the real-time bandwidth count towards the link-share bandwidth? E.g. if A1 and B1 both only have 64kbit/s real-time and 64kbit/s link-share bandwidth, does that mean once they are served 64kbit/s via real-time, their link-share requirement is satisfied as well (they might get excess bandwidth, but lets ignore that for a second) or does that mean they get another 64 kbit/s via link-share? So does each class has a bandwidth "requirement" of real-time plus link-share? Or does a class only have a higher requirement than the real-time curve if the link-share curve is higher than the real-time curve (current link-share requirement equals specified link-share requirement minus real-time bandwidth already provided to this class)? Is upper limit curve applied to real-time as well, only to link-share, or maybe to both? Some tutorials say one way, some say the other way. Some even claim upper-limit is the maximum for real-time bandwidth + link-share bandwidth? What is the truth? Assuming A2 and B2 are both 128 kbit/s, does it make any difference if A1 and B1 are 128 kbit/s link-share only, or 64 kbit/s real-time and 128 kbit/s link-share, and if so, what difference? If I use the seperate real-time curve to increase priorities of classes, why would I need "curves" at all? Why is not real-time a flat value and link-share also a flat value? Why are both curves? The need for curves is clear in the original paper, because there is only one attribute of that kind per class. But now, having three attributes (real-time, link-share, and upper-limit) what for do I still need curves on each one? Why would I want the curves shape (not average bandwidth, but their slopes) to be different for real-time and link-share traffic? According to the little documentation available, real-time curve values are totally ignored for inner classes (class A and B), they are only applied to leaf classes (A1, A2, B1, B2). If that is true, why does the ALTQ HFSC sample configuration (search for 3.3 Sample configuration) set real-time curves on inner classes and claims that those set the guaranteed rate of those inner classes? Isn't that completely pointless? (note: pshare sets the link-share curve in ALTQ and grate the real-time curve; you can see this in the paragraph above the sample configuration). Some tutorials say the sum of all real-time curves may not be higher than 80% of the line speed, others say it must not be higher than 70% of the line speed. Which one is right or are they maybe both wrong? One tutorial said you shall forget all the theory. No matter how things really work (schedulers and bandwidth distribution), imagine the three curves according to the following "simplified mind model": real-time is the guaranteed bandwidth that this class will always get. link-share is the bandwidth that this class wants to become fully satisfied, but satisfaction cannot be guaranteed. In case there is excess bandwidth, the class might even get offered more bandwidth than necessary to become satisfied, but it may never use more than upper-limit says. For all this to work, the sum of all real-time bandwidths may not be above xx% of the line speed (see question above, the percentage varies). Question: Is this more or less accurate or a total misunderstanding of HSFC? And if assumption above is really accurate, where is prioritization in that model? E.g. every class might have a real-time bandwidth (guaranteed), a link-share bandwidth (not guaranteed) and an maybe an upper-limit, but still some classes have higher priority needs than other classes. In that case I must still prioritize somehow, even among real-time traffic of those classes. Would I prioritize by the slope of the curves? And if so, which curve? The real-time curve? The link-share curve? The upper-limit curve? All of them? Would I give all of them the same slope or each a different one and how to find out the right slope? I still haven't lost hope that there exists at least a hand full of people in this world that really understood HFSC and are able to answer all these questions accurately. And doing so without contradicting each other in the answers would be really nice ;-)

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  • Hide horizontal scrollbar in IE 7 and below

    - by Bradley Bell
    Hi all. Basically, I'm having trouble removing the horizontal scrollbar in Internet Explorer 7 and Below. I've tried the code below and It seems to work fine in every browser except IE. overflow-x: hidden; The even bigger problem is that, even though the scrollbar isn't even removed, it seems to completely screw the layout.. It somehow hides the majority of the page content in boxes 2 and 3? It also.. adds a second vertical scrollbar which moves relatively/absolute positioned items down?! I did contemplate just leaving the scrollbar in IE via a specified stylesheet, but even that seems to be messing with the page? The website is on a test directory here.. I'll post the stylesheet in a comment below. Any suggestions? Thanks in advance, hope you can help! Bradley

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  • SQL Server Blocking Issue

    - by Robin Weston
    We currently have an issue that occurs roughly once a day on SQL 2005 database server, although the time it happens is not consistent. Basically, the database grinds to a halt, and starts refusing connections with the following error message. This includes logging into SSMS: A connection was successfully established with the server, but then an error occurred during the login process. (provider: TCP Provider, error: 0 - The specified network name is no longer available.) Our CPU usage for SQL is usually around 15%, but when the DB is in it's broken state it's around 70%, so it's clearly doing something, even if no-one can connect. Even if I disable the web app that uses the database the CPU still doesn't go down. I am unable to restart the SQLSERVER process as it is unresponsive, so I have to end up killing the process manually, which then puts the DB into Suspect/Recovery mode (which I can fix but it's a pain). Below are some PerfMon stats I gathered when the DB was in it's broken state which might help. I have a bunch more if people want to request them: Active Transactions: 2 (Never Changes) Logical Connections: 34 (NC) Process Blocked: 16 (NC) User Connections: 30 (NC) Batch Request: 0 (NC) Active Jobs: 2 (NC) Log Truncations: 596 (NC) Log Shrinks: 24 (NC) Longest Running Transaction Time: 99 (NC) I guess they key is finding out what the DB is using it's CPU on, but as I can't even log into SSMS this isn't possible with the standard methods. Disturbingly, I can't even use the dedicated admin connection to get into SSMS. I get the same timout as with all other requests. Any advice, reccomendations, or even sympathy, is much appreciated!

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  • Make page to tell browser not to cache/preserve input values

    - by queen3
    Most browser cache form input values. So when user refreshes page, the inputs have same values. Here's my problem. When user clicks Save, server validates POSTed data (e.g. checked products), and if not valid, sends it back to browser. However, as stated above, even if server clears selection for some values, they may still be selected because of browser cache! My data has invisible (until parent item selected) checkboxes, so user may be even not aware that some previous value is still selected, until clicks Save again and gets error message - even though user thinks it's not. Which is irritating. This can be resolved by doing Ctrl-F5, but it's not even a solution.Is there automatic/programmatic way to tell browser not to cache form input data on some form/page?

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  • how to reapply knockout binding

    - by MikeW
    Currently I have a knockout binding that stripes rows in a list which works fine ko.bindingHandlers.stripe = { update: function (element, valueAccessor, allBindingsAccessor) { var value = ko.utils.unwrapObservable(valueAccessor()); //creates the dependency var allBindings = allBindingsAccessor(); var even = allBindings.evenClass; var odd = allBindings.oddClass; //update odd rows $(element).children(":nth-child(odd)").addClass(odd).removeClass(even); //update even rows $(element).children(":nth-child(even)").addClass(even).removeClass(odd); ; } } Triggered from <button data-bind="click: addWidget" style="display:none">Add Item</button> The problem I have is when reloading data from the server , I call addWidget() manually in the view model the stripe binding handler is not applied - all rows appear as same color, if I click the html button then the binding happens and stripes appear var ViewModel = function() { self.addWidget(); }); Is it possible to reapply this custom binding manually in js? Thanks Edit: The stripe binding gets applied like so <div data-bind="foreach: widgets, stripe: widgets, evenClass: 'light', oddClass: 'dark'">

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  • DB2 AS400 Java function always returns same value

    - by Nimrod Shory
    Hello, I am writing a user defined function to DB2 on AS/400 in Java and the strangest thing happen.. I am always getting the same result from the function even when i am changing it, even if i am dropping it and create it again and even when i specify NOT DETERMINISTIC.. Does any one have ever encountered a behavior like that?

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  • administrator permission are recommended for running visual studio sp1 on windows 7 rc

    - by vinayakg
    I get this annoying message everytime I try to run visual studio 2005(even using "Run as Administrator" gives same message). I have VS 2005 Professional with all the latest service packs installed including vs2005 SP1 and vs 2005 update for Vista. I am part of the administrators group on my machine. Still I have this problem. Some read on the web suggests that Running program in Compatibility mode solves the problem. Others also recommend turning off the message forever. Well my question is how do I turn off this warning which seems to bother me even if I am part of administrators group. Does Visual Studio does not run in administrator mode even when I am an administrator or even I use "Run as adminsitrator". Also it would be greate if someone out there can highlight what features of Visual Studio wont be available if Visual Studio is launched as a normal user (User is not an administrator/part of the administrator group) on Windows 7.

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  • Can't sign into linkedin when using a QT4 (WebKit-based) browser?

    - by Inshim
    I started using the lightweight QT4 browser for some of the time on my Mac. Most simple websites, and even quite a few AJAX-heavy web apps, work for me flawlessly, including gmail (!) However, with LinkedIn, I can't even manage to sign in. Even when I change the useragent to one of a regular browser, it keeps kicking me out. Any ideas what could be wrong and for some workaround? Thanks!

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  • Why should I use "Web 2.0"-style URLs?

    - by hydrapheetz
    In short, why use something like http://stackoverflow.com/badges/6/supporter instead of something "simpler" (and subjectively, at that) like http://stackoverflow.com/badges/6/. Even on my own site I've just been using /post/6/ to reference posts (by IDs, even though I still store a slug.) Instead of /post/6/small-rant-on-urls, and in some cases, they can get even more absurd, much more so than is really necessary.

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  • Need Help With Simple Regex

    - by npinti
    I have strings of this type: text (more text) What I would like to do is to have a regular expression that extracts the "more text" segment of the string, so far I have been using this regular expression: "^.*\\((.*)\\)$" Which although it works on many cases, it seems to fail if I have something of the sort: text (more text (even more text)) What I get is: even more text) What I would like to get instead is: more text (even more text) (basically the content of the outermost pair of brackets.) Thanks

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  • regular expresson of variables

    - by Kevinniceguy
    what is re of string of 0 and 1 that contain an even number of zeros and even number of ones..... its not or in the middle....its an and...and even number of ones so i got something like (1*01*01*)*(0*10*10*)* does it look good?

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  • Windows Azure: Import/Export Hard Drives, VM ACLs, Web Sockets, Remote Debugging, Continuous Delivery, New Relic, Billing Alerts and More

    - by ScottGu
    Two weeks ago we released a giant set of improvements to Windows Azure, as well as a significant update of the Windows Azure SDK. This morning we released another massive set of enhancements to Windows Azure.  Today’s new capabilities include: Storage: Import/Export Hard Disk Drives to your Storage Accounts HDInsight: General Availability of our Hadoop Service in the cloud Virtual Machines: New VM Gallery, ACL support for VIPs Web Sites: WebSocket and Remote Debugging Support Notification Hubs: Segmented customer push notification support with tag expressions TFS & GIT: Continuous Delivery Support for Web Sites + Cloud Services Developer Analytics: New Relic support for Web Sites + Mobile Services Service Bus: Support for partitioned queues and topics Billing: New Billing Alert Service that sends emails notifications when your bill hits a threshold you define All of these improvements are now available to use immediately (note that some features are still in preview).  Below are more details about them. Storage: Import/Export Hard Disk Drives to Windows Azure I am excited to announce the preview of our new Windows Azure Import/Export Service! The Windows Azure Import/Export Service enables you to move large amounts of on-premises data into and out of your Windows Azure Storage accounts. It does this by enabling you to securely ship hard disk drives directly to our Windows Azure data centers. Once we receive the drives we’ll automatically transfer the data to or from your Windows Azure Storage account.  This enables you to import or export massive amounts of data more quickly and cost effectively (and not be constrained by available network bandwidth). Encrypted Transport Our Import/Export service provides built-in support for BitLocker disk encryption – which enables you to securely encrypt data on the hard drives before you send it, and not have to worry about it being compromised even if the disk is lost/stolen in transit (since the content on the transported hard drives is completely encrypted and you are the only one who has the key to it).  The drive preparation tool we are shipping today makes setting up bitlocker encryption on these hard drives easy. How to Import/Export your first Hard Drive of Data You can read our Getting Started Guide to learn more about how to begin using the import/export service.  You can create import and export jobs via the Windows Azure Management Portal as well as programmatically using our Server Management APIs. It is really easy to create a new import or export job using the Windows Azure Management Portal.  Simply navigate to a Windows Azure storage account, and then click the new Import/Export tab now available within it (note: if you don’t have this tab make sure to sign-up for the Import/Export preview): Then click the “Create Import Job” or “Create Export Job” commands at the bottom of it.  This will launch a wizard that easily walks you through the steps required: For more comprehensive information about Import/Export, refer to Windows Azure Storage team blog.  You can also send questions and comments to the [email protected] email address. We think you’ll find this new service makes it much easier to move data into and out of Windows Azure, and it will dramatically cut down the network bandwidth required when working on large data migration projects.  We hope you like it. HDInsight: 100% Compatible Hadoop Service in the Cloud Last week we announced the general availability release of Windows Azure HDInsight. HDInsight is a 100% compatible Hadoop service that allows you to easily provision and manage Hadoop clusters for big data processing in Windows Azure.  This release is now live in production, backed by an enterprise SLA, supported 24x7 by Microsoft Support, and is ready to use for production scenarios. HDInsight allows you to use Apache Hadoop tools, such as Pig and Hive, to process large amounts of data in Windows Azure Blob Storage. Because data is stored in Windows Azure Blob Storage, you can choose to dynamically create Hadoop clusters only when you need them, and then shut them down when they are no longer required (since you pay only for the time the Hadoop cluster instances are running this provides a super cost effective way to use them).  You can create Hadoop clusters using either the Windows Azure Management Portal (see below) or using our PowerShell and Cross Platform Command line tools: The import/export hard drive support that came out today is a perfect companion service to use with HDInsight – the combination allows you to easily ingest, process and optionally export a limitless amount of data.  We’ve also integrated HDInsight with our Business Intelligence tools, so users can leverage familiar tools like Excel in order to analyze the output of jobs.  You can find out more about how to get started with HDInsight here. Virtual Machines: VM Gallery Enhancements Today’s update of Windows Azure brings with it a new Virtual Machine gallery that you can use to create new VMs in the cloud.  You can launch the gallery by doing New->Compute->Virtual Machine->From Gallery within the Windows Azure Management Portal: The new Virtual Machine Gallery includes some nice enhancements that make it even easier to use: Search: You can now easily search and filter images using the search box in the top-right of the dialog.  For example, simply type “SQL” and we’ll filter to show those images in the gallery that contain that substring. Category Tree-view: Each month we add more built-in VM images to the gallery.  You can continue to browse these using the “All” view within the VM Gallery – or now quickly filter them using the category tree-view on the left-hand side of the dialog.  For example, by selecting “Oracle” in the tree-view you can now quickly filter to see the official Oracle supplied images. MSDN and Supported checkboxes: With today’s update we are also introducing filters that makes it easy to filter out types of images that you may not be interested in. The first checkbox is MSDN: using this filter you can exclude any image that is not part of the Windows Azure benefits for MSDN subscribers (which have highly discounted pricing - you can learn more about the MSDN pricing here). The second checkbox is Supported: this filter will exclude any image that contains prerelease software, so you can feel confident that the software you choose to deploy is fully supported by Windows Azure and our partners. Sort options: We sort gallery images by what we think customers are most interested in, but sometimes you might want to sort using different views. So we’re providing some additional sort options, like “Newest,” to customize the image list for what suits you best. Pricing information: We now provide additional pricing information about images and options on how to cost effectively run them directly within the VM Gallery. The above improvements make it even easier to use the VM Gallery and quickly create launch and run Virtual Machines in the cloud. Virtual Machines: ACL Support for VIPs A few months ago we exposed the ability to configure Access Control Lists (ACLs) for Virtual Machines using Windows PowerShell cmdlets and our Service Management API. With today’s release, you can now configure VM ACLs using the Windows Azure Management Portal as well. You can now do this by clicking the new Manage ACL command in the Endpoints tab of a virtual machine instance: This will enable you to configure an ordered list of permit and deny rules to scope the traffic that can access your VM’s network endpoints. For example, if you were on a virtual network, you could limit RDP access to a Windows Azure virtual machine to only a few computers attached to your enterprise. Or if you weren’t on a virtual network you could alternatively limit traffic from public IPs that can access your workloads: Here is the default behaviors for ACLs in Windows Azure: By default (i.e. no rules specified), all traffic is permitted. When using only Permit rules, all other traffic is denied. When using only Deny rules, all other traffic is permitted. When there is a combination of Permit and Deny rules, all other traffic is denied. Lastly, remember that configuring endpoints does not automatically configure them within the VM if it also has firewall rules enabled at the OS level.  So if you create an endpoint using the Windows Azure Management Portal, Windows PowerShell, or REST API, be sure to also configure your guest VM firewall appropriately as well. Web Sites: Web Sockets Support With today’s release you can now use Web Sockets with Windows Azure Web Sites.  This feature enables you to easily integrate real-time communication scenarios within your web based applications, and is available at no extra charge (it even works with the free tier).  Higher level programming libraries like SignalR and socket.io are also now supported with it. You can enable Web Sockets support on a web site by navigating to the Configure tab of a Web Site, and by toggling Web Sockets support to “on”: Once Web Sockets is enabled you can start to integrate some really cool scenarios into your web applications.  Check out the new SignalR documentation hub on www.asp.net to learn more about some of the awesome scenarios you can do with it. Web Sites: Remote Debugging Support The Windows Azure SDK 2.2 we released two weeks ago introduced remote debugging support for Windows Azure Cloud Services. With today’s Windows Azure release we are extending this remote debugging support to also work with Windows Azure Web Sites. With live, remote debugging support inside of Visual Studio, you are able to have more visibility than ever before into how your code is operating live in Windows Azure. It is now super easy to attach the debugger and quickly see what is going on with your application in the cloud. Remote Debugging of a Windows Azure Web Site using VS 2013 Enabling the remote debugging of a Windows Azure Web Site using VS 2013 is really easy.  Start by opening up your web application’s project within Visual Studio. Then navigate to the “Server Explorer” tab within Visual Studio, and click on the deployed web-site you want to debug that is running within Windows Azure using the Windows Azure->Web Sites node in the Server Explorer.  Then right-click and choose the “Attach Debugger” option on it: When you do this Visual Studio will remotely attach the debugger to the Web Site running within Windows Azure.  The debugger will then stop the web site’s execution when it hits any break points that you have set within your web application’s project inside Visual Studio.  For example, below I set a breakpoint on the “ViewBag.Message” assignment statement within the HomeController of the standard ASP.NET MVC project template.  When I hit refresh on the “About” page of the web site within the browser, the breakpoint was triggered and I am now able to debug the app remotely using Visual Studio: Note above how we can debug variables (including autos/watchlist/etc), as well as use the Immediate and Command Windows. In the debug session above I used the Immediate Window to explore some of the request object state, as well as to dynamically change the ViewBag.Message property.  When we click the the “Continue” button (or press F5) the app will continue execution and the Web Site will render the content back to the browser.  This makes it super easy to debug web apps remotely. Tips for Better Debugging To get the best experience while debugging, we recommend publishing your site using the Debug configuration within Visual Studio’s Web Publish dialog. This will ensure that debug symbol information is uploaded to the Web Site which will enable a richer debug experience within Visual Studio.  You can find this option on the Web Publish dialog on the Settings tab: When you ultimately deploy/run the application in production we recommend using the “Release” configuration setting – the release configuration is memory optimized and will provide the best production performance.  To learn more about diagnosing and debugging Windows Azure Web Sites read our new Troubleshooting Windows Azure Web Sites in Visual Studio guide. Notification Hubs: Segmented Push Notification support with tag expressions In August we announced the General Availability of Windows Azure Notification Hubs - a powerful Mobile Push Notifications service that makes it easy to send high volume push notifications with low latency from any mobile app back-end.  Notification hubs can be used with any mobile app back-end (including ones built using our Mobile Services capability) and can also be used with back-ends that run in the cloud as well as on-premises. Beginning with the initial release, Notification Hubs allowed developers to send personalized push notifications to both individual users as well as groups of users by interest, by associating their devices with tags representing the logical target of the notification. For example, by registering all devices of customers interested in a favorite MLB team with a corresponding tag, it is possible to broadcast one message to millions of Boston Red Sox fans and another message to millions of St. Louis Cardinals fans with a single API call respectively. New support for using tag expressions to enable advanced customer segmentation With today’s release we are adding support for even more advanced customer targeting.  You can now identify customers that you want to send push notifications to by defining rich tag expressions. With tag expressions, you can now not only broadcast notifications to Boston Red Sox fans, but take that segmenting a step farther and reach more granular segments. This opens up a variety of scenarios, for example: Offers based on multiple preferences—e.g. send a game day vegetarian special to users tagged as both a Boston Red Sox fan AND a vegetarian Push content to multiple segments in a single message—e.g. rain delay information only to users who are tagged as either a Boston Red Sox fan OR a St. Louis Cardinal fan Avoid presenting subsets of a segment with irrelevant content—e.g. season ticket availability reminder to users who are tagged as a Boston Red Sox fan but NOT also a season ticket holder To illustrate with code, consider a restaurant chain app that sends an offer related to a Red Sox vs Cardinals game for users in Boston. Devices can be tagged by your app with location tags (e.g. “Loc:Boston”) and interest tags (e.g. “Follows:RedSox”, “Follows:Cardinals”), and then a notification can be sent by your back-end to “(Follows:RedSox || Follows:Cardinals) && Loc:Boston” in order to deliver an offer to all devices in Boston that follow either the RedSox or the Cardinals. This can be done directly in your server backend send logic using the code below: var notification = new WindowsNotification(messagePayload); hub.SendNotificationAsync(notification, "(Follows:RedSox || Follows:Cardinals) && Loc:Boston"); In your expressions you can use all Boolean operators: AND (&&), OR (||), and NOT (!).  Some other cool use cases for tag expressions that are now supported include: Social: To “all my group except me” - group:id && !user:id Events: Touchdown event is sent to everybody following either team or any of the players involved in the action: Followteam:A || Followteam:B || followplayer:1 || followplayer:2 … Hours: Send notifications at specific times. E.g. Tag devices with time zone and when it is 12pm in Seattle send to: GMT8 && follows:thaifood Versions and platforms: Send a reminder to people still using your first version for Android - version:1.0 && platform:Android For help on getting started with Notification Hubs, visit the Notification Hub documentation center.  Then download the latest NuGet package (or use the Notification Hubs REST APIs directly) to start sending push notifications using tag expressions.  They are really powerful and enable a bunch of great new scenarios. TFS & GIT: Continuous Delivery Support for Web Sites + Cloud Services With today’s Windows Azure release we are making it really easy to enable continuous delivery support with Windows Azure and Team Foundation Services.  Team Foundation Services is a cloud based offering from Microsoft that provides integrated source control (with both TFS and Git support), build server, test execution, collaboration tools, and agile planning support.  It makes it really easy to setup a team project (complete with automated builds and test runners) in the cloud, and it has really rich integration with Visual Studio. With today’s Windows Azure release it is now really easy to enable continuous delivery support with both TFS and Git based repositories hosted using Team Foundation Services.  This enables a workflow where when code is checked in, built successfully on an automated build server, and all tests pass on it – I can automatically have the app deployed on Windows Azure with zero manual intervention or work required. The below screen-shots demonstrate how to quickly setup a continuous delivery workflow to Windows Azure with a Git-based ASP.NET MVC project hosted using Team Foundation Services. Enabling Continuous Delivery to Windows Azure with Team Foundation Services The project I’m going to enable continuous delivery with is a simple ASP.NET MVC project whose source code I’m hosting using Team Foundation Services.  I did this by creating a “SimpleContinuousDeploymentTest” repository there using Git – and then used the new built-in Git tooling support within Visual Studio 2013 to push the source code to it.  Below is a screen-shot of the Git repository hosted within Team Foundation Services: I can access the repository within Visual Studio 2013 and easily make commits with it (as well as branch, merge and do other tasks).  Using VS 2013 I can also setup automated builds to take place in the cloud using Team Foundation Services every time someone checks in code to the repository: The cool thing about this is that I don’t have to buy or rent my own build server – Team Foundation Services automatically maintains its own build server farm and can automatically queue up a build for me (for free) every time someone checks in code using the above settings.  This build server (and automated testing) support now works with both TFS and Git based source control repositories. Connecting a Team Foundation Services project to Windows Azure Once I have a source repository hosted in Team Foundation Services with Automated Builds and Testing set up, I can then go even further and set it up so that it will be automatically deployed to Windows Azure when a source code commit is made to the repository (assuming the Build + Tests pass).  Enabling this is now really easy.  To set this up with a Windows Azure Web Site simply use the New->Compute->Web Site->Custom Create command inside the Windows Azure Management Portal.  This will create a dialog like below.  I gave the web site a name and then made sure the “Publish from source control” checkbox was selected: When we click next we’ll be prompted for the location of the source repository.  We’ll select “Team Foundation Services”: Once we do this we’ll be prompted for our Team Foundation Services account that our source repository is hosted under (in this case my TFS account is “scottguthrie”): When we click the “Authorize Now” button we’ll be prompted to give Windows Azure permissions to connect to the Team Foundation Services account.  Once we do this we’ll be prompted to pick the source repository we want to connect to.  Starting with today’s Windows Azure release you can now connect to both TFS and Git based source repositories.  This new support allows me to connect to the “SimpleContinuousDeploymentTest” respository we created earlier: Clicking the finish button will then create the Web Site with the continuous delivery hooks setup with Team Foundation Services.  Now every time someone pushes source control to the repository in Team Foundation Services, it will kick off an automated build, run all of the unit tests in the solution , and if they pass the app will be automatically deployed to our Web Site in Windows Azure.  You can monitor the history and status of these automated deployments using the Deployments tab within the Web Site: This enables a really slick continuous delivery workflow, and enables you to build and deploy apps in a really nice way. Developer Analytics: New Relic support for Web Sites + Mobile Services With today’s Windows Azure release we are making it really easy to enable Developer Analytics and Monitoring support with both Windows Azure Web Site and Windows Azure Mobile Services.  We are partnering with New Relic, who provide a great dev analytics and app performance monitoring offering, to enable this - and we have updated the Windows Azure Management Portal to make it really easy to configure. Enabling New Relic with a Windows Azure Web Site Enabling New Relic support with a Windows Azure Web Site is now really easy.  Simply navigate to the Configure tab of a Web Site and scroll down to the “developer analytics” section that is now within it: Clicking the “add-on” button will display some additional UI.  If you don’t already have a New Relic subscription, you can click the “view windows azure store” button to obtain a subscription (note: New Relic has a perpetually free tier so you can enable it even without paying anything): Clicking the “view windows azure store” button will launch the integrated Windows Azure Store experience we have within the Windows Azure Management Portal.  You can use this to browse from a variety of great add-on services – including New Relic: Select “New Relic” within the dialog above, then click the next button, and you’ll be able to choose which type of New Relic subscription you wish to purchase.  For this demo we’ll simply select the “Free Standard Version” – which does not cost anything and can be used forever:  Once we’ve signed-up for our New Relic subscription and added it to our Windows Azure account, we can go back to the Web Site’s configuration tab and choose to use the New Relic add-on with our Windows Azure Web Site.  We can do this by simply selecting it from the “add-on” dropdown (it is automatically populated within it once we have a New Relic subscription in our account): Clicking the “Save” button will then cause the Windows Azure Management Portal to automatically populate all of the needed New Relic configuration settings to our Web Site: Deploying the New Relic Agent as part of a Web Site The final step to enable developer analytics using New Relic is to add the New Relic runtime agent to our web app.  We can do this within Visual Studio by right-clicking on our web project and selecting the “Manage NuGet Packages” context menu: This will bring up the NuGet package manager.  You can search for “New Relic” within it to find the New Relic agent.  Note that there is both a 32-bit and 64-bit edition of it – make sure to install the version that matches how your Web Site is running within Windows Azure (note: you can configure your Web Site to run in either 32-bit or 64-bit mode using the Web Site’s “Configuration” tab within the Windows Azure Management Portal): Once we install the NuGet package we are all set to go.  We’ll simply re-publish the web site again to Windows Azure and New Relic will now automatically start monitoring the application Monitoring a Web Site using New Relic Now that the application has developer analytics support with New Relic enabled, we can launch the New Relic monitoring portal to start monitoring the health of it.  We can do this by clicking on the “Add Ons” tab in the left-hand side of the Windows Azure Management Portal.  Then select the New Relic add-on we signed-up for within it.  The Windows Azure Management Portal will provide some default information about the add-on when we do this.  Clicking the “Manage” button in the tray at the bottom will launch a new browser tab and single-sign us into the New Relic monitoring portal associated with our account: When we do this a new browser tab will launch with the New Relic admin tool loaded within it: We can now see insights into how our app is performing – without having to have written a single line of monitoring code.  The New Relic service provides a ton of great built-in monitoring features allowing us to quickly see: Performance times (including browser rendering speed) for the overall site and individual pages.  You can optionally set alert thresholds to trigger if the speed does not meet a threshold you specify. Information about where in the world your customers are hitting the site from (and how performance varies by region) Details on the latency performance of external services your web apps are using (for example: SQL, Storage, Twitter, etc) Error information including call stack details for exceptions that have occurred at runtime SQL Server profiling information – including which queries executed against your database and what their performance was And a whole bunch more… The cool thing about New Relic is that you don’t need to write monitoring code within your application to get all of the above reports (plus a lot more).  The New Relic agent automatically enables the CLR profiler within applications and automatically captures the information necessary to identify these.  This makes it super easy to get started and immediately have a rich developer analytics view for your solutions with very little effort. If you haven’t tried New Relic out yet with Windows Azure I recommend you do so – I think you’ll find it helps you build even better cloud applications.  Following the above steps will help you get started and deliver you a really good application monitoring solution in only minutes. Service Bus: Support for partitioned queues and topics With today’s release, we are enabling support within Service Bus for partitioned queues and topics. Enabling partitioning enables you to achieve a higher message throughput and better availability from your queues and topics. Higher message throughput is achieved by implementing multiple message brokers for each partitioned queue and topic.  The  multiple messaging stores will also provide higher availability. You can create a partitioned queue or topic by simply checking the Enable Partitioning option in the custom create wizard for a Queue or Topic: Read this article to learn more about partitioned queues and topics and how to take advantage of them today. Billing: New Billing Alert Service Today’s Windows Azure update enables a new Billing Alert Service Preview that enables you to get proactive email notifications when your Windows Azure bill goes above a certain monetary threshold that you configure.  This makes it easier to manage your bill and avoid potential surprises at the end of the month. With the Billing Alert Service Preview, you can now create email alerts to monitor and manage your monetary credits or your current bill total.  To set up an alert first sign-up for the free Billing Alert Service Preview.  Then visit the account management page, click on a subscription you have setup, and then navigate to the new Alerts tab that is available: The alerts tab allows you to setup email alerts that will be sent automatically once a certain threshold is hit.  For example, by clicking the “add alert” button above I can setup a rule to send myself email anytime my Windows Azure bill goes above $100 for the month: The Billing Alert Service will evolve to support additional aspects of your bill as well as support multiple forms of alerts such as SMS.  Try out the new Billing Alert Service Preview today and give us feedback. Summary Today’s Windows Azure release enables a ton of great new scenarios, and makes building applications hosted in the cloud even easier. If you don’t already have a Windows Azure account, you can sign-up for a free trial and start using all of the above features today.  Then visit the Windows Azure Developer Center to learn more about how to build apps with it. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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  • When Your Boss Doesn't Want you to Succeed

    - by Phil Factor
    You're working hard to get an application finished. You are programming long into the evenings sometimes, and eating sandwiches at your desk instead of taking a lunch break. Then one day you glance up at the IT manager, serene in his mysterious round of meetings, and think 'Does he actually care whether this project succeeds or not?'. The question may seem absurd. Of course the project must succeed. The truth, as always, is often far more complex. Your manager may even be doing his best to make sure you don't succeed. Why? There have always been rich pickings for the unscrupulous in IT.  In extreme cases, where administrators struggle with scarcely-comprehended technical issues, huge sums of money can be lost and gained without any perceptible results. In a very few cases can fraud be proven: most of the time, the intricacies of the 'game' are such that one can do little more than harbor suspicion.  Where does over-enthusiastic salesmanship end and fraud begin? The Business of Information Technology provides rich opportunities for White-collar crime. The poor developer has his, or her, hands full with the task of wrestling with the sheer complexity of building an application. He, or she, has no time for following the complexities of the chicanery of the management that is directing affairs.  Most likely, the developers wouldn't even suspect that their company management had ulterior motives. I'll illustrate what I mean with an entirely fictional, hypothetical, example. The Opportunist and the Aged Charities often do good, unexciting work that is funded by the income from a bequest that dates back maybe hundreds of years.  In our example, it isn't exciting work, for it involves the welfare of elderly people who have fallen on hard times.  Volunteers visit, giving a smile and a chat, and check that they are all right, but are able to spend a little money on their discretion to ameliorate any pressing needs for these old folk.  The money is made to work very hard and the charity averts a great deal of suffering and eases the burden on the state. Daisy hears the garden gate creak as Mrs Rainer comes up the path. She looks forward to her twice-weekly visit from the nice lady from the trust. She always asked ‘is everything all right, Love’. Cheeky but nice. She likes her cheery manner. She seems interested in hearing her memories, and talking about her far-away family. She helps her with those chores in the house that she couldn’t manage and once even paid to fill the back-shed with coke, the other year. Nice, Mrs. Rainer is, she thought as she goes to open the door. The trustees are getting on in years themselves, and worry about the long-term future of the charity: is it relevant to modern society? Is it likely to attract a new generation of workers to take it on. They are instantly attracted by the arrival to the board of a smartly dressed University lecturer with the ear of the present Government. Alain 'Stalin' Jones is earnest, persuasive and energetic. The trustees welcome him to the board and quickly forgive his humorless political-correctness. He talks of 'diversity', 'relevance', 'social change', 'equality' and 'communities', but his eye is on that huge bequest. Alain first came to notice as a Trotskyite union official, who insinuated himself into one of the duller Trades Unions and turned it, through his passionate leadership, into a radical, headline-grabbing organization.  Middle age, and the rise of European federal socialism, had brought him quiet prosperity and charcoal suits, an ear in the current government, and a wide influence as a member of various Quangos (government bodies staffed by well-paid unelected courtiers).  He was employed as a 'consultant' by several organizations that relied on government contracts. After gaining the confidence of the trustees, and showing a surprising knowledge of mundane processes and the regulatory framework of charities, Alain launches his plan.  The trust will expand their work by means of a bold IT initiative that will coordinate the interventions of several 'caring agencies', and provide  emergency cover, a special Website so anxious relatives can see how their elderly charges are doing, and a vastly more efficient way of coordinating the work of the volunteer carers. It will also provide a special-purpose site that gives 'social networking' facilities, rather like Facebook, to the few elderly folk on the lists with access to the internet. The trustees perk up. Their own experience of the internet is restricted to the occasional scanning of railway timetables, but they can see that it is 'relevant'. In his next report to the other trustees, Alain proudly announces that all this glamorous and exciting technology can be paid for by a grant from the government. He admits darkly that he has influence. True to his word, the government promises a grant of a size that is an order of magnitude greater than any budget that the trustees had ever handled. There was the understandable proviso that the company that would actually do the IT work would have to be one of the government's preferred suppliers and the work would need to be tendered under EU competition rules. The only company that tenders, a multinational IT company with a long track record of government work, quotes ten million pounds for the work. A trustee questions the figure as it seems enormous for the reasonably trivial internet facilities being built, but the IT Salesmen dazzle them with presentations and three-letter acronyms until they subside into quiescent acceptance. After all, they can’t stay locked in the Twentieth century practices can they? The work is put in hand with a large project team, in a splendid glass building near west London. The trustees see rooms of programmers working diligently at screens, and who talk with enthusiasm of the project. Paul, the project manager, looked through his resource schedule with growing unease. His initial excitement at being given his first major project hadn’t lasted. He’d been allocated a lackluster team of developers whose skills didn’t seem right, and he was allowed only a couple of contractors to make good the deficit. Strangely, the presentation he’d given to his management, where he’d saved time and resources with a OTS solution to a great deal of the development work, and a sound conservative architecture, hadn’t gone down nearly as big as he’d hoped. He almost got the feeling they wanted a more radical and ambitious solution. The project starts slipping its dates. The costs build rapidly. There are certain uncomfortable extra charges that appear, such as the £600-a-day charge by the 'Business Manager' appointed to act as a point of liaison between the charity and the IT Company.  When he appeared, his face permanently split by a 'Mr Sincerity' smile, they'd thought he was provided at the cost of the IT Company. Derek, the DBA, didn’t have to go to the server room quite some much as he did: but It got him away from the poisonous despair of the development group. Wave after wave of events had conspired to delay the project.  Why the management had imposed hideous extra bureaucracy to cover ISO 9000 and 9001:2008 accreditation just as the project was struggling to get back on-schedule was  beyond belief.  Then  the Business manager was coming back with endless changes in scope, sorrowing saying that the Trustees were very insistent, though hopelessly out in touch with the reality of technical challenges. Suddenly, the costs mount to the point of consuming the government grant in its entirety. The project remains tantalizingly just out of reach. Alain Jones gives an emotional rallying speech at the trustees review meeting, urging them not to lose their nerve. Sadly, the trustees dip into the accumulated capital of the trust, the seed-corn of all their revenues, in order to save the IT project. A few months later it is all over. The IT project is never delivered, even though it had seemed so incredibly close.  With the trust's capital all gone, the activities it funded have to be terminated and the trust becomes just a shell. There aren't even the funds to mount a legal challenge against the IT company, even had the trust's solicitor advised such a foolish thing. Alain leaves as suddenly as he had arrived, only to pop up a few months later, bronzed and rested, at another charity. The IT workers who were permanent employees are dispersed to other projects, and the contractors leave to other contracts. Within months the entire project is but a vague memory. One or two developers remain  puzzled that their managers had been so obstructive when they should have welcomed progress toward completion of the project, but they put it down to incompetence and testosterone. Few suspected that they were actively preventing the project from getting finished. The relationships between the IT consultancy, and the government of the day are intricate, and made more complex by the Private Finance initiatives and political patronage.  The losers in this case were the taxpayers, and the beneficiaries of the trust, and, perhaps the soul of the original benefactor of the trust, whose bid to give his name some immortality had been scuppered by smooth-talking white-collar political apparatniks.  Even now, nobody is certain whether a crime was ever committed. The perfect heist, I guess. Where’s the victim? "I hear that Daisy’s cottage is up for sale. She’s had to go into a care home.  She didn’t want to at all, but then there is nobody to keep an eye on her since she had that minor stroke a while back.  A charity used to help out. The ‘social’ don’t have the funding, evidently for community care. Yes, her old cat was put down. There was a good clearout, and now the house is all scrubbed and cleared ready for sale. The skip was full of old photos and letters, memories. No room in her new ‘home’."

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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. Latest Features How-To Geek ETC How To Make Hundreds of Complex Photo Edits in Seconds With Photoshop Actions How to Enable User-Specific Wireless Networks in Windows 7 How to Use Google Chrome as Your Default PDF Reader (the Easy Way) How To Remove People and Objects From Photographs In Photoshop Ask How-To Geek: How Can I Monitor My Bandwidth Usage? Internet Explorer 9 RC Now Available: Here’s the Most Interesting New Stuff Smart Taskbar Is a Thumb Friendly Android Task Launcher Comix is an Awesome Comics Archive Viewer for Linux Get the MakeUseOf eBook Guide to Speeding Up Windows for Free Need Tech Support? Call the Star Wars Help Desk! [Video Classic] Reclaim Vertical UI Space by Adding a Toolbar to the Left or Right Side of Firefox Androidify Turns You into an Android-style Avatar

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  • Issues configuring Exchange 2010 as well as SSL problems.

    - by Eric Smith
    Possibly-Relevant Background Info: I've recently moved up from icky shared hosting to a glorious, Remote Desktop-administrated VPS server running Windows Server 2008 R2. Even though I'm only 21 now and a computer science major, I've tried to play with every Windows Server release since '03, just to learn new things. What usually happens is inevitably I'll do something wrong and pretty much ruin the install. You're dealing with an amateur here :) Through the past few months of working with my new server, I've mastered DNS, IIS, got Team Foundation Server running (yay!), and can install all of the other basics like SQL Server and Active Directory. The Problem: Now, these last few weeks I've been trying to install Exchange Server 2010 (SP1). To make a long story short, it took me several attempts, and I even had to get my server wiped just so I could start fresh since Exchange decided uninstalling properly was for sissies (cost me $20, bah). Today, at long last, I got Exchange mostly working. There were two main problems left, however, that left me unsatisfied: Exchange installed itself and all of its child sites into Default Web Site. I wanted to access Exchange via mail.domain.com, but instead everything was configured to domain.com. My limited server admin knowledge was not enough to configure IIS or Exchange to move itself over to the website I had set up for it, appropriately titled 'mail.domain.com', which I had bound to a dedicated IP address (I was told this was necessary, but he may have been wrong). I have two SSL certificates: one for my main domain and one for my mail subdomain. For whatever reason, I had issues geting Exchange to use my mail certificate, even though I had assigned the proper roles in the MMC. I did, at one point, get it to work (or mostly work, anyways. Frankly, my memory of today is clouded by intense frustration). Additionally, I was confused which type of SSL certificate I should be using for Exchange. My SSL provider, GoDaddy, allows me to request a new certificate whenever, so I can use either the certificate request provided by IIS or the more complicated and specific request you can create with Exchange. Which type should I be using, the IIS or Exchange certificate? If I must use the Exchange certificate, will that 1) cause issues when I bind that certificate to my mail.domain.com subdomain or 2) is that an unnecessary step? The SSL Certificate Strikes Back When I thought I had the proper SSL certificate assigned for those brief, sweet moments, Google Chrome reported the correct mail.domain.com certificate when browsing https://mail.domain.com. However, Outlook 2010 threw up an error when trying to configure my email account claiming that the certificate didn't match the domain of "mail.domain.com". Is this an issue that will be resolved by problem #2 or is it a separate one entirely? Apologies for the massive wall of text, but I wanted to provide as much info as I possibly could. Exchange is the last thing I'd like installed on my server, and naturally it's turning out to be the hardest. Thanks for any info at all. Even a point in a vague direction would be a huge help at this point. Thanks! -Eric P.S.: The reason I keep ruining my install is that when I attempt to uninstall Exchange, something invariably goes wrong. The last time the uninstaller complained that there was still a mailbox active and it couldn't proceed until I deleted it. ... The only mailbox left was the Administrator account, the built-in one I couldn't delete. So I attempted to manually uninstall it following several guides online only to now be stuck unable to launch the installer and have to get my system wiped AGAIN for the second time today ($40 down the drain, bah!). I do not understand at all why "uninstall" just can't mean "hey, you, delete everything and go away". There's not even a force uninstall option, only a "recover system" option that just fails to fix anything and makes it so I can't even use the GUI uninstaller. </rant>

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  • VMWare Network bug in multiple VMWare Workstation versions if using a hardcoded IP address

    - by onyxruby
    I'm having a very tricky problem with some of my VM sessions being unable to reach the Internet or even ping the gateway. I have just set up a new VM Workstation (7) on a W2K8 64bit server (I'll be converting to ESXI 4 once I can find a decent book on it, so for the meanwhile I use workstation). I have imported a number of VM's and setup some new ones on the server.In short the problem with some of the VM's being unable to reach the Internet is that they can't reach the gateway. I've looking at a number of things and can pretty safely rule out the following: Switch, Router, DHCP Server, DNS, Client IP configuration, Routes and typos. The problem is that some of the new clients cannot reach the gateway if their IP address is hardcoded, they can't even ping it by IP address. That rules out DNS and DHCP. Now, if I allow them to get their IP address by DHCP they can reach the gateway and Internet without issue. The interesting thing on this, is that this behavior occurs even if I leave the DNS information hardcoded under TCP/IP settings. It doesn't work unless the IP and gateway are handed out by DHCP even though the same information IP info is being used by the host. Fundamentally from the standpoint of the clients, they are trying to reach the exact same gateway using the exact same IP information regardless of whether they are hardcoded or assigned by DHCP. Here's an example of one client. IP Address 192.168.7.66 - Subnet Mask 255.255.255.0 - Gateway 192.168.7.254 - DNS1 192.168.7.44 - DNS2 192.168.7.254. The issue occurs across six different microsoft operating systems, Windows 7 and Windows 2008 variants all have the issue. My W2K3, XP, Vista and W98 clients all work without issue with hardcoded IP addresses. I have tried things like rearranging the DNS order, flushing DNS and so on. It's not a routing or switch issue as the clients can work just fine if they get their IP by DHCP. It's not a paramater issue as the exact same paramaters are handed out by DHCP as I plug in by hand. It's not a DNS issue as clients cant reach other clients even with IP addresses only. I have run a tracert to the gateway by IP address and it times out on the very first hop before failing on hop3 with destination host unreachable. If I get the IP address by DHCP the tracert finds the gateway (and Internet) without issue. I have read a few other posts online in forums talking about this problem randomly occuring over the years in other VM versions as well, so I suspect some kind of long standing bug. Does anyone have any ideas on this? Is it possibly a bug with Windows 7 and W2K clients under VM?

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  • Frequent and weird wifi disconnections

    - by Sidou
    How would you explain, troubleshoot (and solve) the following problem? Wifi ADSL modem router D-link 2640R installed in living room at about 1.8m height. Working fine, synchronising and getting/serving stable internet connection. First situation: -Laptop 01 in other end of the house, let's say in room01 southern to the living room, distant by about 15m. Getting stable signal of good to very good quality. No disconnection. -Laptop 02 in room02 opposite to room01 (5m West) which makes it almost at the same distance and direction from the router located 15m North. Getting stable signal of good to very good quality. No disconnection. Second situation: -Laptop 01 moved to room03 Northern to the living room (actually just 3m behind the wall where the router lies). Getting stable signal of excellent quality. No disconnection. -Laptop 02 still in room02 but now experiences frequent disconnections (actually almost impossible to get the Internet even though the signal level is still very good. Either no Internet with the wifi icon appearing connected to access point or no connection established at all which happens every 2 minutes and that means virtually no Internet at all as I can just get a timeframe of 1 minute or so to load any website or even get to the router's web based control panel. If Laptop 01 is completely shut down or its wifi adapters shut down or even still working but its wifi MAC address forbidden, then Laptop 02 has no problem at all. If Laptop 02 is moved to a nearer location to the router, in the living room for instance, then no connection problem occurs even if Laptop 01 is also connected. And also if we move back Laptop 01 to its original location (room 01), then no problem as well. I'm completely lost and don't know how to address this issue. I tried to change the Wifi channel and even tried the auto channel scan but that didn't solve it. I know that the problem is probably coming from Laptop 01 being in its new location or some sort of interference as the problem occurs only under the described condition but I have no idea how to solve it! I also scanned the neighborhood for wifi jam using InSSIDer, there are few other access points but they don't seem to affect the situation. Any ideas about the steps to follow or tools to use ?

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