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• disks not ready in array causes mdadm to force initramfs shell

  - by RaidPinata

  Okay, this is starting to get pretty frustrating. I've read most of the other answers on this site that have anything to do with this issue but I'm still not getting anywhere. I have a RAID 6 array with 10 devices and 1 spare. The OS is on a completely separate device. At boot only three of the 10 devices in the raid are available, the others become available later in the boot process. Currently, unless I go through initramfs I can't get the system to boot - it just hangs with a blank screen. When I do boot through recovery (initramfs), I get a message asking if I want to assemble the degraded array. If I say no and then exit initramfs the system boots fine and my array is mounted exactly where I intend it to. Here are the pertinent files as near as I can tell. Ask me if you want to see anything else. # mdadm.conf # # Please refer to mdadm.conf(5) for information about this file. # # by default (built-in), scan all partitions (/proc/partitions) and all # containers for MD superblocks. alternatively, specify devices to scan, using # wildcards if desired. #DEVICE partitions containers # auto-create devices with Debian standard permissions # CREATE owner=root group=disk mode=0660 auto=yes # automatically tag new arrays as belonging to the local system HOMEHOST <system> # instruct the monitoring daemon where to send mail alerts MAILADDR root # definitions of existing MD arrays # This file was auto-generated on Tue, 13 Nov 2012 13:50:41 -0700 # by mkconf $Id$ ARRAY /dev/md0 level=raid6 num-devices=10 metadata=1.2 spares=1 name=Craggenmore:data UUID=37eea980:24df7b7a:f11a1226:afaf53ae Here is fstab # /etc/fstab: static file system information. # # Use 'blkid' to print the universally unique identifier for a # device; this may be used with UUID= as a more robust way to name devices # that works even if disks are added and removed. See fstab(5). # # <file system> <mount point> <type> <options> <dump> <pass> # / was on /dev/sdc2 during installation UUID=3fa1e73f-3d83-4afe-9415-6285d432c133 / ext4 errors=remount-ro 0 1 # swap was on /dev/sdc3 during installation UUID=c4988662-67f3-4069-a16e-db740e054727 none swap sw 0 0 # mount large raid device on /data /dev/md0 /data ext4 defaults,nofail,noatime,nobootwait 0 0 output of cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid6 sda[0] sdd[10](S) sdl[9] sdk[8] sdj[7] sdi[6] sdh[5] sdg[4] sdf[3] sde[2] sdb[1] 23441080320 blocks super 1.2 level 6, 512k chunk, algorithm 2 [10/10] [UUUUUUUUUU] unused devices: <none> Here is the output of mdadm --detail --scan --verbose ARRAY /dev/md0 level=raid6 num-devices=10 metadata=1.2 spares=1 name=Craggenmore:data UUID=37eea980:24df7b7a:f11a1226:afaf53ae devices=/dev/sda,/dev/sdb,/dev/sde,/dev/sdf,/dev/sdg,/dev/sdh,/dev/sdi,/dev/sdj,/dev/sdk,/dev/sdl,/dev/sdd Please let me know if there is anything else you think might be useful in troubleshooting this... I just can't seem to figure out how to change the boot process so that mdadm waits until the drives are ready to build the array. Everything works just fine if the drives are given enough time to come online. edit: changed title to properly reflect situation

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• PowerShell Script To Find Where SharePoint 2010 Features Are Activated

  - by Brian Jackett

  The script on this post will find where features are activated within your SharePoint 2010 farm.   Problem    Over the past few months I’ve gotten literally dozens of emails, blog comments, or personal requests from people asking “how do I find where a SharePoint feature has been activated?”  I wrote a script to find which features are installed on your farm almost 3 years ago.  There is also the Get-SPFeature PowerShell commandlet in SharePoint 2010.  The problem is that these only tell you if a feature is installed not where they have been activated.  This is especially important to know if you have multiple web applications, site collections, and /or sites.   Solution    The default call (no parameters) for Get-SPFeature will return all features in the farm.  Many of the parameter sets accept filters for specific scopes such as web application, site collection, and site.  If those are supplied then only the enabled / activated features are returned for that filtered scope.  Taking the concept of recursively traversing a SharePoint farm and merging that with calls to Get-SPFeature at all levels of the farm you can find out what features are activated at that level.  Store the results into a variable and you end up with all features that are activated at every level.    Below is the script I came up with (slight edits for posting on blog).  With no parameters the function lists all features activated at all scopes.  If you provide an Identity parameter you will find where a specific feature is activated.  Note that the display name for a feature you see in the SharePoint UI rarely matches the “internal” display name.  I would recommend using the feature id instead.  You can download a full copy of the script by clicking on the link below.    Note: This script is not optimized for medium to large farms.  In my testing it took 1-3 minutes to recurse through my demo environment.  This script is provided as-is with no warranty.  Run this in a smaller dev / test environment first.   001 002 003 004 005 006 007 008 009 010 011 012 013 014 015 016 017 018 019 020 021 022 023 024 025 026 027 028 029 030 031 032 033 034 035 036 037 038 039 040 041 042 043 044 045 046 047 048 049 050 051 052 053 054 055 056 057 058 059 060 061 062 063 064 065 066 067 068 function Get-SPFeatureActivated { # see full script for help info, removed for formatting [CmdletBinding()] param(   [Parameter(position = 1, valueFromPipeline=$true)]   [Microsoft.SharePoint.PowerShell.SPFeatureDefinitionPipeBind]   $Identity )#end param   Begin   {     # declare empty array to hold results. Will add custom member `     # for Url to show where activated at on objects returned from Get-SPFeature.     $results = @()         $params = @{}   }   Process   {     if([string]::IsNullOrEmpty($Identity) -eq $false)     {       $params = @{Identity = $Identity             ErrorAction = "SilentlyContinue"       }     }       # check farm features     $results += (Get-SPFeature -Farm -Limit All @params |              % {Add-Member -InputObject $_ -MemberType noteproperty `                 -Name Url -Value ([string]::Empty) -PassThru} |              Select-Object -Property Scope, DisplayName, Id, Url)     # check web application features     foreach($webApp in (Get-SPWebApplication))     {       $results += (Get-SPFeature -WebApplication $webApp -Limit All @params |                % {Add-Member -InputObject $_ -MemberType noteproperty `                   -Name Url -Value $webApp.Url -PassThru} |                Select-Object -Property Scope, DisplayName, Id, Url)       # check site collection features in current web app       foreach($site in ($webApp.Sites))       {         $results += (Get-SPFeature -Site $site -Limit All @params |                  % {Add-Member -InputObject $_ -MemberType noteproperty `                     -Name Url -Value $site.Url -PassThru} |                  Select-Object -Property Scope, DisplayName, Id, Url)                          $site.Dispose()         # check site features in current site collection         foreach($web in ($site.AllWebs))         {           $results += (Get-SPFeature -Web $web -Limit All @params |                    % {Add-Member -InputObject $_ -MemberType noteproperty `                       -Name Url -Value $web.Url -PassThru} |                    Select-Object -Property Scope, DisplayName, Id, Url)           $web.Dispose()         }       }     }   }   End   {     $results   } } #end Get-SPFeatureActivated   Snippet of output from Get-SPFeatureActivated   Conclusion    This script has been requested for a long time and I’m glad to finally getting a working “clean” version.  If you find any bugs or issues with the script please let me know.  I’ll be posting this to the TechNet Script Center after some internal review.  Enjoy the script and I hope it helps with your admin / developer needs.         -Frog Out

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• My collection of favourite TFS utilities

  - by Aaron Kowall

  So, you’re in charge of your company or team’s Team Foundation Server.  Wish it was easier to manage, administer, extend?  Well, here are a few utilities that I highly recommend looking at. I’ve recently had need to rebuild my laptop and upgrade my local TFS environment to TFS 2012 Update 1.  This gave me cause to enumerate some of the utilities I like to have on hand. One of the reasons I love to use TFS on projects is that it’s basically a complete ALM toolkit.  Everything from Task Management, Version Control, Build Management, Test Management, Metrics and Reporting are all there ‘in the box’.  However, no matter how complete a product set it, there are always ways to make it better.  Here are a list of utilities and libraries that are pretty generally useful.  this is not intended to be an exhaustive list of TFS extensions but rather a set that I recommend you look at.  There are many more out there that may be applicable in one scenario or another.  This set of tools should work with TFS 2012 or 2010 if you grab the right version. Most of these tools (and more) are available from the Visual Studio Gallery or CodePlex. General TFS Power Tools – This is ‘the’ collection of utilities and extensions delivered by the Product Group.  Highly recommended from here are the Best Practice Analyzer for ensuring your TFS implementation is healthy and the Team Foundation Server Backups to ensure your TFS databases are backed up correctly. TFS Administrators Toolkit – helps make updates to work item types and reports across many team projects.  Also provides visibility of disk usage by finding large files in version control or test attachments to assist in managing storage utilization. Version Control Git-TF - a set of cross-platform, command line tools that facilitate sharing of changes between TFS and Git. These tools allow a developer to use a local Git repository, and configure it to share changes with a TFS server.  Great for all Git lovers who must integrate into a TFS repository. Testing TFS 2012 Tester Power Tool – A utility for bulk copying test cases which assists in an approach for managing test cases across multiple releases.  A little plug that this utility was written and maintained by Anna Russo of Imaginet where I also work. Test Scribe - A documentation power tool designed to construct documents directly from the TFS for test plan and test run artifacts for the purpose of discussion, reporting etc. Reporting Community TFS Report Extensions - a single repository of SQL Server Reporting Services report for Team Foundation 2010 (and above).  Check out the Test Plan Status report by Imaginet’s Steve St. Jean.  Very valuable for your test managers. Builds TFS Build Manager – A great utility if you are build manager over a complex build environment with many TFS build definitions. Community TFS Build Extensions – contains many custom build activities.  Current release binaries are for TFS 2010 but many of the activities can be recompiled for use with TFS 2012. While compiling this list, I was surprised by the number of TFS utilities and extensions I no longer use/need in TFS 2012 because of the great work by the TFS team addressing many gaps since the 2010 release. Are there any utilities you depend on that I’ve missed?  I’d love to hear about them in the comments!

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• Where Twitter Stands Heading Into 2013

  - by Mike Stiles

  As Twitter continued throughout 2012 to be a stage on which global politics and culture played itself out, the company itself underwent some adjustments that give us a good indication of what users and brands can expect from the platform in 2013. The power of the network did anything but fade. Celebrities continued to use it to connect one-on-one. Even the Pope signed on this year. It continued to fuel revolutions. It played an exponentially large factor in this US Presidential election. And around the world, the freedom to speak was challenged as users were fired, sued, sometimes even jailed for their tweets. Expect more of the same in 2013, as Twitter has entrenched itself, for individuals, causes and brands, as the fastest, easiest, most efficient way to message the masses so some measure of impact can come from it. It’s changed everything, and it’s not finished. These fun facts reveal the position of strength with which Twitter enters 2013: It now generates a billion tweets every 2.5 days It has 500 million+ users The average Twitter user has tweeted 307 times 32% of everyone using the Internet uses Twitter It’s expected to bring in $540 million in ad revenue by 2014 11 new accounts are created every second High-level Executive Summary: people love it, people use it, and they’re going to keep loving and using it. Whether or not outside developers love it is a different matter. 2012 marked a shift from welcoming the third party support that played at least some role in Twitter being so warmly embraced, to discouraging anything that replicates what Twitter can do itself…or plans to do itself. It’s not the open playground it once was. Now Twitter must spend 2013 proving it can innovate in-house and keep us just as entranced. Likewise, Twitter is distancing itself from Facebook. Images from the #1 platform’s Instagram don’t work on Twitter anymore, and Twitter’s rolling out their own photo filter product. Where the two have lived in a “plenty of room for everybody” symbiosis up to now, 2013 could see the giants ramping up a full-on rivalry. Twitter is exhibiting a deliberate strategy. Updates have centered on more visually appealing search results, and making finding and sharing content easier. Deals have been cut with some media entities so their content stands out. CEO Dick Costolo has said tweets aren’t the attraction, they’re what leads you to content. Twitter aims to be a key distributor of media and info. Add the addition of former News Corp. President Peter Chernin to the board, and their hashtag landing page experience for events, and their media behemoth ambitions get pretty clear. There are challenges ahead and Costolo has also laid those out; entry into China, figuring out how to have Twitter deliver both comprehensive and relevant, targeted experiences, and the visualization of big data. What does this mean for corporations? They can expect a more media-rich evolution and growing emphases on imagery. They can expect more opportunities to create great media content and leverage Twitter for its distribution. And they can expect new ways to surface in searches. Are brands diving in? 56% of customer tweets to companies get completely and totally ignored. Ugh. A study Twitter recently conducted with Compete shows people who see tweets from retailers are more likely to buy a product. And, the more retailer tweets they see, the more likely they are to purchase on the retail site. As more of those tweets point to engaging media content from the brand, the results should get even better. Twitter appears ready for 2013. Enterprise brands have some work to do. @mikestilesPhoto Stuart Miles, freedigitalphotos.net

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• Let Me Show You Something: Instagram, Vine and Snapchat for Brands

  - by Mike Stiles

  While brands are well aware of how much more impactful images are than text-only posts on social channels, today you’re additionally being presented with platform after additional platform for hosting, doctoring and sharing photos and videos.  Can you play in every sandbox? And if you do, can you be brilliant on all of them? As has usually been the case, so far brands are sticking their toes into new platforms while not actually committing to them, or strategizing for them, or resourcing them. TrackMaven found of the 123 F500 companies using Instagram, only 22% of them are active on it. Likewise, research from Simply Measured found brands are indeed jumping in, with the number establishing a presence on Instagram up 55% over the past year. Users want them there…brand engagement has exploded 350%, and over 1/3 of the top brands have at least 10,000 followers. BUT…the top 10 brands are generating 33% of all posts, reaping 83% of all engagement. Things are also growing on Twitter’s Vine, the 6-second looping video app that hit 40 million users in August. The 7th Chamber says 5 tweets a second contain a Vine link. Other studies say branded Vines are 4 times more likely to be shared and seen than rank-and-file branded videos. Why? Users know that even if a video is pure junk, they won’t get robbed of too much of their valuable time. Vine is always upgrading so you can make sure your videos are worth viewers’ time. You can now edit videos, and save & work on several projects concurrently. What you can’t do is upload a finely crafted video into Vine, but you can do that with Instagram. The key to success? Same as with all other content; make it of value. Deliver a laugh or a lesson or both. How-to, behind the scenes peeks, contests, demos, all make sense in the short video format. Or follow Nash Grier’s example, which is to just have fun with and connect to your viewers, earning their trust that your next Vine will be as good as the last. Nash is only 15, has over 1.4 million followers, and adds about 100,000 a week. He broke out when one of his videos was re-Vined by some other kid with 300,000 followers. Make good stuff, get it in front of influencers, and your brand Vines could break out as well. Then there’s Snapchat, the “this photo will self destruct” platform. How can that be of use to brands besides offering coupons that really expire? The jury is out. But with an audience of over 100 million and a valuation of $800 million, media-with-a-time-limit is compelling. Now there’s “Snapchat Stories” that can last 24 hours and be shared to the public at large. You might be able to capitalize on how much more focus gets put on content when there’s a time limit on its availability. The underlying truth to all of this is, these are all tools. Very cool, feature rich tools, but tools. You can give the exact same art kit to 5 different people and you’d get back 5 very different works, ranging from worthless garbage to masterpiece. Brands are being called upon to be still and moving image artists. That’s what your customers are used to seeing, from a variety of sources. Commit to communicating with them accordingly. @mikestiles Photo: stock.xchng

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• Efficiently separating Read/Compute/Write steps for concurrent processing of entities in Entity/Component systems

  - by TravisG

  Setup I have an entity-component architecture where Entities can have a set of attributes (which are pure data with no behavior) and there exist systems that run the entity logic which act on that data. Essentially, in somewhat pseudo-code: Entity { id; map<id_type, Attribute> attributes; } System { update(); vector<Entity> entities; } A system that just moves along all entities at a constant rate might be MovementSystem extends System { update() { for each entity in entities position = entity.attributes["position"]; position += vec3(1,1,1); } } Essentially, I'm trying to parallelise update() as efficiently as possible. This can be done by running entire systems in parallel, or by giving each update() of one system a couple of components so different threads can execute the update of the same system, but for a different subset of entities registered with that system. Problem In reality, these systems sometimes require that entities interact(/read/write data from/to) each other, sometimes within the same system (e.g. an AI system that reads state from other entities surrounding the current processed entity), but sometimes between different systems that depend on each other (i.e. a movement system that requires data from a system that processes user input). Now, when trying to parallelize the update phases of entity/component systems, the phases in which data (components/attributes) from Entities are read and used to compute something, and the phase where the modified data is written back to entities need to be separated in order to avoid data races. Otherwise the only way (not taking into account just "critical section"ing everything) to avoid them is to serialize parts of the update process that depend on other parts. This seems ugly. To me it would seem more elegant to be able to (ideally) have all processing running in parallel, where a system may read data from all entities as it wishes, but doesn't write modifications to that data back until some later point. The fact that this is even possible is based on the assumption that modification write-backs are usually very small in complexity, and don't require much performance, whereas computations are very expensive (relatively). So the overhead added by a delayed-write phase might be evened out by more efficient updating of entities (by having threads work more % of the time instead of waiting). A concrete example of this might be a system that updates physics. The system needs to both read and write a lot of data to and from entities. Optimally, there would be a system in place where all available threads update a subset of all entities registered with the physics system. In the case of the physics system this isn't trivially possible because of race conditions. So without a workaround, we would have to find other systems to run in parallel (which don't modify the same data as the physics system), other wise the remaining threads are waiting and wasting time. However, that has disadvantages Practically, the L3 cache is pretty much always better utilized when updating a large system with multiple threads, as opposed to multiple systems at once, which all act on different sets of data. Finding and assembling other systems to run in parallel can be extremely time consuming to design well enough to optimize performance. Sometimes, it might even not be possible at all because a system just depends on data that is touched by all other systems. Solution? In my thinking, a possible solution would be a system where reading/updating and writing of data is separated, so that in one expensive phase, systems only read data and compute what they need to compute, and then in a separate, performance-wise cheap, write phase, attributes of entities that needed to be modified are finally written back to the entities. The Question How might such a system be implemented to achieve optimal performance, as well as making programmer life easier? What are the implementation details of such a system and what might have to be changed in the existing EC-architecture to accommodate this solution?

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• An Actionable Common Approach to Federal Enterprise Architecture

  - by TedMcLaughlan

  The recent “Common Approach to Federal Enterprise Architecture” (US Executive Office of the President, May 2 2012) is extremely timely and well-organized guidance for the Federal IT investment and deployment community, as useful for Federal Departments and Agencies as it is for their stakeholders and integration partners. The guidance not only helps IT Program Planners and Managers, but also informs and prepares constituents who may be the beneficiaries or otherwise impacted by the investment. The FEA Common Approach extends from and builds on the rapidly-maturing Federal Enterprise Architecture Framework (FEAF) and its associated artifacts and standards, already included to a large degree in the annual Federal Portfolio and Investment Management processes – for example the OMB’s Exhibit 300 (i.e. Business Case justification for IT investments).A very interesting element of this Approach includes the very necessary guidance for actually using an Enterprise Architecture (EA) and/or its collateral – good guidance for any organization charged with maintaining a broad portfolio of IT investments. The associated FEA Reference Models (i.e. the BRM, DRM, TRM, etc.) are very helpful frameworks for organizing, understanding, communicating and standardizing across agencies with respect to vocabularies, architecture patterns and technology standards. Determining when, how and to what level of detail to include these reference models in the typically long-running Federal IT acquisition cycles wasn’t always clear, however, particularly during the first interactions of a Program’s technical and functional leadership with the Mission owners and investment planners. This typically occurs as an agency begins the process of describing its strategy and business case for allocation of new Federal funding, reacting to things like new legislation or policy, real or anticipated mission challenges, or straightforward ROI opportunities (for example the introduction of new technologies that deliver significant cost-savings).The early artifacts (i.e. Resource Allocation Plans, Acquisition Plans, Exhibit 300’s or other Business Case materials, etc.) of the intersection between Mission owners, IT and Program Managers are far easier to understand and discuss, when the overlay of an evolved, actionable Enterprise Architecture (such as the FEA) is applied.  “Actionable” is the key word – too many Public Service entity EA’s (including the FEA) have for too long been used simply as a very highly-abstracted standards reference, duly maintained and nominally-enforced by an Enterprise or System Architect’s office. Refreshing elements of this recent FEA Common Approach include one of the first Federally-documented acknowledgements of the “Solution Architect” (the “Problem-Solving” role). This role collaborates with the Enterprise, System and Business Architecture communities primarily on completing actual “EA Roadmap” documents. These are roadmaps grounded in real cost, technical and functional details that are fully aligned with both contextual expectations (for example the new “Digital Government Strategy” and its required roadmap deliverables - and the rapidly increasing complexities of today’s more portable and transparent IT solutions.  We also expect some very critical synergies to develop in early IT investment cycles between this new breed of “Federal Enterprise Solution Architect” and the first waves of the newly-formal “Federal IT Program Manager” roles operating under more standardized “critical competency” expectations (including EA), likely already to be seriously influencing the quality annual CPIC (Capital Planning and Investment Control) processes.  Our Oracle Enterprise Strategy Team (EST) and associated Oracle Enterprise Architecture (OEA) practices are already engaged in promoting and leveraging the visibility of Enterprise Architecture as a key contributor to early IT investment validation, and we look forward in particular to seeing the real, citizen-centric benefits of this FEA Common Approach in particular surface across the entire Public Service CPIC domain - Federal, State, Local, Tribal and otherwise. Read more Enterprise Architecture blog posts for additional EA insight!

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• Doubts about several best practices for rest api + service layer

  - by TheBeefMightBeTough

  I'm going to be starting a project soon that exposes a restful api for business intelligence. It may not be limited to a restful api, so I plan to delegate requests to a service layer that then coordinates multiple domain objects (each of which have business logic local to the object). The api will likely have many calls as it is a long-term project. While thinking about the design, I recalled a few best practices. 1) Use command objects at the controller layer (I'm using Spring MVC). 2) Use DTOs at the service layer. 3) Validate in both the controller and service layer, though for different reasons. I have my doubts about these recommendations. 1) Using command objects adds a lot of extra single-purpose classes (potentially one per request). What exactly is the benefit? Annotation based validation can be done using this approach, sure. What if I have two requests that take the same parameters, but have different validation requirements? I would have to have two different classes with exactly the same members but different annotations? Bleh. 2) I have heard that using DTOs is preferable to parameters because it makes for more maintainable code down the road (say, e.g., requirements change and the service parameters need to be altered). I don't quite understand this. Shouldn't an api be more-or-less set in stone? I would understand that in the early phases of a project (or, especially, an entire company) the domain itself will not be well understood, and thus core domain objects may change along with the apis that manipulate these objects. At this point however the number of api methods should be small and their dependents few, so changes to the methods could easily be tolerated from a maintainability standpoint. In a large api with many methods and a substantial domain model, I would think having a DTO for potentially each domain object would become unwieldy. Am I misunderstanding something here? 3) I see validation in the controller and service layer as redundant in most cases. Why would I validate that parameters are not null and are in general well formed in the controller if the service is going to do exactly the same (and more). Couldn't I just do all the validation in the service and throw a runtime exception with a list of bad parameters then catch that in the controller to make the error messages more presentable? Better yet, couldn't I just make the error messages user-friendly in the service and let the exception trickle up to a global handler (ControllerAdvice in spring, for example)? Is there something wrong with either of these approaches? (I do see a use case for controller validation if the input does not map one-to-one with the service input, but since the controllers are for a rest api and not forms, the api parameters will probably map directly to service parameters.) I do also have a question about unchecked vs checked exceptions. Namely, I'm not really sure why I'd ever want to use a checked exception. Every time I have seen them used they just get wrapped into general exceptions (DomainException, SystemException, ApplicationException, w/e) to reduce the signature length of methods, or devs catch Exception rather than dealing with the App1Exception, App2Exception, Sys1Exception, Sys2Exception. I don't see how either of these practices is very useful. Why not just use unchecked exceptions always and catch the ones you actually do care about? You could just document what unchecked exceptions the method throws.

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• More Stuff less Fluff

  - by brendonpage

  Originally posted on: http://geekswithblogs.net/brendonpage/archive/2013/11/08/more-stuff-less-fluff.aspxYAGNI – "You Aren't Going To Need It". This is an acronym commonly used in software development to remind developers to only write what they need. This acronym exists because software developers have gotten into the habit of writing everything they need to solve a problem and then everything they think they're going to possibly need in the future. Since we can't predict the future this results in a large portion of the code that we write never being used. That extra code causes unnecessary complexity, which makes it harder to understand and harder to modify when we inevitably have to write something that we didn't think of. I've known about YAGNI for some time now but I never really got it. The words made sense and the idea was clear but the concept never sank in. I was one of those devs who'd happily write a ton of code in the anticipation of future needs. In my mind this was an essential part of writing high quality code. I didn't realise that in doing so I was actually writing low quality code. If you are anything like me you are probably thinking "Lies and propaganda! High quality code needs to be future proof." I agree! But what makes code future proof? If we could see into the future the answer would be simple, code that allows for or meets all future requirements. Since we can't see the future the best we can do is write code that can easily adapt to future requirements, this means writing flexible code. Flexible code is: Fast to understand. Fast to add to. Fast to modify. To be flexible code has to be simple, this means only making it as complex as it needs to be to meet those 3 criteria. That is high quality code. YAGNI! The art is in deciding where to place the seams (abstractions) that will give you flexibility without making decisions about future functionality. Robert C Martin explains it very nicely, he says a good architecture allows you to defer decisions because if you can defer a decision then you have the flexibility to change it. I've recently had a YAGNI experience which brought this all into perspective. I was working on a new project which had multiple clients that connect to a server hosted in the cloud. I was tasked with adding a feature to the desktop client that would allow users to capture items that would then be saved to the cloud. My immediate thought was "Hey we have multiple clients so I should build a web service for these items, that way we can access them from other clients", so I went to work and this is what I created.  I stood back and gazed upon what I'd created with a warm fuzzy feeling. It was beautiful! Then the time came for the team to use the design I'd created for another feature with a new entity. Let's just say that they didn't get the same warm fuzzy feeling that I did when they looked at the design. After much discussion they eventually got it through to me that I'd bloated the design based on an assumption of future functionality. After much more discussion we cut the design down to the following. This design gives us future flexibility with no extra work, it is as complex as it needs to be. It has been a couple of months since this incident and we still haven't needed to access either of the entities from other clients. Using the simpler design allowed us to do more stuff with less stuff!

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• SQL Server Optimizer Malfunction?

  - by Tony Davis

  There was a sharp intake of breath from the audience when Adam Machanic declared the SQL Server optimizer to be essentially "stuck in 1997". It was during his fascinating "Query Tuning Mastery: Manhandling Parallelism" session at the recent PASS SQL Summit. Paraphrasing somewhat, Adam (blog | @AdamMachanic) offered a convincing argument that the optimizer often delivers flawed plans based on assumptions that are no longer valid with today’s hardware. In 1997, when Microsoft engineers re-designed the database engine for SQL Server 7.0, SQL Server got its initial implementation of a cost-based optimizer. Up to SQL Server 2000, the developer often had to deploy a steady stream of hints in SQL statements to combat the occasionally wilful plan choices made by the optimizer. However, with each successive release, the optimizer has evolved and improved in its decision-making. It is still prone to the occasional stumble when we tackle difficult problems, join large numbers of tables, perform complex aggregations, and so on, but for most of us, most of the time, the optimizer purrs along efficiently in the background. Adam, however, challenged further any assumption that the current optimizer is competent at providing the most efficient plans for our more complex analytical queries, and in particular of offering up correctly parallelized plans. He painted a picture of a present where complex analytical queries have become ever more prevalent; where disk IO is ever faster so that reads from disk come into buffer cache faster than ever; where the improving RAM-to-data ratio means that we have a better chance of finding our data in cache. Most importantly, we have more CPUs at our disposal than ever before. To get these queries to perform, we not only need to have the right indexes, but also to be able to split the data up into subsets and spread its processing evenly across all these available CPUs. Improvements such as support for ColumnStore indexes are taking things in the right direction, but, unfortunately, deficiencies in the current Optimizer mean that SQL Server is yet to be able to exploit properly all those extra CPUs. Adam’s contention was that the current optimizer uses essentially the same costing model for many of its core operations as it did back in the days of SQL Server 7, based on assumptions that are no longer valid. One example he gave was a "slow disk" bias that may have been valid back in 1997 but certainly is not on modern disk systems. Essentially, the optimizer assesses the relative cost of serial versus parallel plans based on the assumption that there is no IO cost benefit from parallelization, only CPU. It assumes that a single request will saturate the IO channel, and so a query would not run any faster if we parallelized IO because the disk system simply wouldn’t be able to handle the extra pressure. As such, the optimizer often decides that a serial plan is lower cost, often in cases where a parallel plan would improve performance dramatically. It was challenging and thought provoking stuff, as were his techniques for driving parallelism through query logic based on subsets of rows that define the "grain" of the query. I highly recommend you catch the session if you missed it. I’m interested to hear though, when and how often people feel the force of the optimizer’s shortcomings. Barring mistakes, such as stale statistics, how often do you feel the Optimizer fails to find the plan you think it should, and what are the most common causes? Is it fighting to induce it toward parallelism? Combating unexpected plans, arising from table partitioning? Something altogether more prosaic? Cheers, Tony.

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• Where should you put constants and why?

  - by Tim Meyer

  In our mostly large applications, we usually have a only few locations for constants: One class for GUI and internal contstants (Tab Page titles, Group Box titles, calculation factors, enumerations) One class for database tables and columns (this part is generated code) plus readable names for them (manually assigned) One class for application messages (logging, message boxes etc) The constants are usually separated into different structs in those classes. In our C++ applications, the constants are only defined in the .h file and the values are assigned in the .cpp file. One of the advantages is that all strings etc are in one central place and everybody knows where to find them when something must be changed. This is especially something project managers seem to like as people come and go and this way everybody can change such trivial things without having to dig into the application's structure. Also, you can easily change the title of similar Group Boxes / Tab Pages etc at once. Another aspect is that you can just print that class and give it to a non-programmer who can check if the captions are intuitive, and if messages to the user are too detailed or too confusing etc. However, I see certain disadvantages: Every single class is tightly coupled to the constants classes Adding/Removing/Renaming/Moving a constant requires recompilation of at least 90% of the application (Note: Changing the value doesn't, at least for C++). In one of our C++ projects with 1500 classes, this means around 7 minutes of compilation time (using precompiled headers; without them it's around 50 minutes) plus around 10 minutes of linking against certain static libraries. Building a speed optimized release through the Visual Studio Compiler takes up to 3 hours. I don't know if the huge amount of class relations is the source but it might as well be. You get driven into temporarily hard-coding strings straight into code because you want to test something very quickly and don't want to wait 15 minutes just for that test (and probably every subsequent one). Everybody knows what happens to the "I will fix that later"-thoughts. Reusing a class in another project isn't always that easy (mainly due to other tight couplings, but the constants handling doesn't make it easier.) Where would you store constants like that? Also what arguments would you bring in order to convince your project manager that there are better concepts which also comply with the advantages listed above? Feel free to give a C++-specific or independent answer. PS: I know this question is kind of subjective but I honestly don't know of any better place than this site for this kind of question. Update on this project I have news on the compile time thing: Following Caleb's and gbjbaanb's posts, I split my constants file into several other files when I had time. I also eventually split my project into several libraries which was now possible much easier. Compiling this in release mode showed that the auto-generated file which contains the database definitions (table, column names and more - more than 8000 symbols) and builds up certain hashes caused the huge compile times in release mode. Deactivating MSVC's optimizer for the library which contains the DB constants now allowed us to reduce the total compile time of your Project (several applications) in release mode from up to 8 hours to less than one hour! We have yet to find out why MSVC has such a hard time optimizing these files, but for now this change relieves a lot of pressure as we no longer have to rely on nightly builds only. That fact - and other benefits, such as less tight coupling, better reuseability etc - also showed that spending time splitting up the "constants" wasn't such a bad idea after all ;-)

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• Get to Know a Candidate (3 of 25): Virgil Goode&ndash;Constitution Party

  - by Brian Lanham

  DISCLAIMER: This is not a post about “Romney” or “Obama”. This is not a post for whom I am voting. Information sourced for Wikipedia. Meet Virgil Goode of the Constitution Party Goode was served as a Republican member of the United States House of Representatives from 1997 to 2009. He represented the 5th congressional district of Virginia. Goode was born in Richmond, Virginia, the son of Alice Clara (née Besecker) and Virgil Hamlin Goode. He has spent most of his life in Rocky Mount. Goode graduated with a B.A. from the University of Richmond (Phi Beta Kappa) and with a J.D. from the University of Virginia School of Law. He also is a member of Lambda Chi Alpha Fraternity and served in the Army National Guard from 1969 to 1975. Goode grew up as a Democrat. He entered politics soon after graduating from law school. At the age of 27, he won a special election to the state Senate from a Southside district as an independent after the death of the Democratic incumbent. One of his major campaign focuses at the time was advocacy for the Equal Rights Amendment. Soon after being elected, he joined the Democrats. Goode wore his party ties very loosely. He became famous for his support of the tobacco industry, expressing his fear that "his elderly mother would be denied 'the one last pleasure' of smoking a cigarette on her hospital deathbed." He was an ardent defender of gun rights while being an enthusiastic supporter of L. Douglas Wilder, who later became the first elected black governor in the history of the United States. At the Democratic Party's state political convention in 1985, Goode nominated Wilder for lieutenant governor. However, while governor, Wilder cracked down on the sale of guns in the state. After the 1995 elections resulted in a 20–20 split between Democrats and Republicans in the State Senate, Goode seriously considered voting with the Republicans on organizing the chamber. Had he done so, the State Senate would have been under Republican control for the first time since Reconstruction (the Republicans ultimately won control outright in 1999). Goode's actions at the time "forced his party to share power with Republican lawmakers in the state legislature," which further upset the Democratic Party. Goode is on the ballot in CA, FL, ID, IO, LA, MI, MN, MS, MI, NJ, NM, NY, NV, ND, OH, SC, SD, TN, UT, VA, WA, WI, WY.  He is a write-in candidate in CA, CT, DC, GA, IL, IN, ME, MD, MA, MO, NC, TX, VT, WV Constitution Party This party was founded as the “U.S. Taxpayers’ Party” and considers itself conservative. The party's platform is predicated on the principles of the nation's founding documents. The party puts a large focus on immigration, calling for stricter penalties towards illegal immigrants and a moratorium on legal immigration until all federal subsidies to immigrants are discontinued.The party absorbed the American Independent Party, originally founded for George Wallace's 1968 presidential campaign. The American Independent Party of California has been an affiliate of the Constitution Party since its founding; however, current party leadership is disputed and the issue is in court to resolve this conflict. The Constitution Party has some substantial support from the Christian Right and in 2010 achieved major party status in Colorado. Learn more about Virgil Goode and Constitution Party on Wikipedia.

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• A Reusable Builder Class for .NET testing

  - by Liam McLennan

  When writing tests, other than end-to-end integration tests, we often need to construct test data objects. Of course this can be done using the class’s constructor and manually configuring the object, but to get many objects into a valid state soon becomes a large percentage of the testing effort. After many years of painstakingly creating builders for each of my domain objects I have finally become lazy enough to bother to write a generic, reusable builder class for .NET. To use it you instantiate a instance of the builder and configuring it with a builder method for each class you wish it to be able to build. The builder method should require no parameters and should return a new instance of the type in a default, valid state. In other words the builder method should be a Func<TypeToBeBuilt>. The best way to make this clear is with an example. In my application I have the following domain classes that I want to be able to use in my tests: public class Person { public string Name { get; set; } public int Age { get; set; } public bool IsAndroid { get; set; } } public class Building { public string Street { get; set; } public Person Manager { get; set; } } The builder for this domain is created like so: build = new Builder(); build.Configure(new Dictionary<Type, Func<object>> { {typeof(Building), () => new Building {Street = "Queen St", Manager = build.A<Person>()}}, {typeof(Person), () => new Person {Name = "Eugene", Age = 21}} }); Note how Building depends on Person, even though the person builder method is not defined yet. Now in a test I can retrieve a valid object from the builder: var person = build.A<Person>(); If I need a class in a customised state I can supply an Action<TypeToBeBuilt> to mutate the object post construction: var person = build.A<Person>(p => p.Age = 99); The power and efficiency of this approach becomes apparent when your tests require larger and more complex objects than Person and Building. When I get some time I intend to implement the same functionality in Javascript and Ruby. Here is the full source of the Builder class: public class Builder { private Dictionary<Type, Func<object>> defaults; public void Configure(Dictionary<Type, Func<object>> defaults) { this.defaults = defaults; } public T A<T>() { if (!defaults.ContainsKey(typeof(T))) throw new ArgumentException("No object of type " + typeof(T).Name + " has been configured with the builder."); T o = (T)defaults[typeof(T)](); return o; } public T A<T>(Action<T> customisation) { T o = A<T>(); customisation(o); return o; } }

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• Walkthrough: Scheduling jobs using Quartz.net &ndash; Part 1: What is Quartz.Net?

  - by Tarun Arora

  Quartz.NET is a full-featured, open source enterprise job scheduling system written in .NET platform that can be used from smallest apps to large scale enterprise systems. What is the problem that we trying to address? I want to schedule the execution of a task but only when something happens. Let’s call that something a trigger, so... if the trigger is met => execute the task. Sounds simple, why not use windows task scheduler for this? Well, windows task scheduler is great for tasks where the trigger can be easily defined. With windows task scheduler will you be able to schedule a task to run on every working day according to the UK calendar (exclude all weekends & bank holidays) without either writing the logic for day check in the task or a wrapper script calling into the task. The task should just contain the execution logic and should not have anything to do with the schedule for execution; Quartz.net allows you to achieve this and lots more. A quartz.net trigger gives you the flexibility for task invocation based on the following triggers, 1. at a certain time of day (to the millisecond) 2. on certain days of the week 3. on certain days of the month 4. on certain days of the year 5. not on certain days listed within a registered Calendar (such as business holidays) 6. repeated a specific number of times 7. repeated until a specific time/date 8. repeated indefinitely 9. repeated with a delay interval Did 8 – repeat indefinitely just ring a bell? I’ll be covering that in the future post. Using Quartz.net as a windows service You can have Quartz.net run as a standalone instance within its own .NET virtual machine instance via .NET Remoting. Let’s take a look at typical application architecture. In the figure below, I have the application tier set up on Machine 1, database set up on Machine 2 and Quartz.net set up on Machine 3 which is normally the architecture for most (if not all) enterprise applications. Figure 1 -  Typical Application architecture while using Quartz.net as a windows service What other options do I have if I don’t want to use Quartz.net? Quartz.net is just one of the many job scheduling services. Have a look at this comprehensive list of free and paid enterprise job scheduling software along with their feature comparison. http://en.wikipedia.org/wiki/List_of_job_scheduler_software This was first in the series of posts on enterprise scheduling using Quartz.net, in the next post I’ll be covering how to Install Quartz.net as a windows service. Thank you for taking the time out and reading this blog post. If you enjoyed the post, remember to subscribe to http://feeds.feedburner.com/TarunArora. Stay tuned!

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• Retrofit Certification

  - by Bill Evjen

  Impact of Regulations on Cabin Systems Installation John Courtright, Structural Integrity Engineering There are “heightened” FAA attention to technical issues related to IFE and Wi-Fi Systems Installations The Aging Aircraft Safety Rule – EWIS & Damage Tolerance Analysis The Challenge: Maximize Flight Safety While Minimizing Costs Issue Papers & Testing, Testing, Testing The role of Airworthiness Directives (ADs) on the design of many IFE systems and all antenna systems. Goal is safety AND cost-effective maintenance intervals and inspection techniques The STC Process Briefly Stated Type Certifications (TC) Supplemental Type Certifications (STC) The STC Process Project Specific Certification Plan (PSCP) Managed by FAA Aircraft Certification Office (ACO) Type of Project (Electrical/Mechanical Systems or Structural) Specific Type of Aircraft Being Modified Schedule Design & Installation Location What does the STC Plan (PSCP) Cover? System Description – What does the system do? System qualification – Are the components qualified? Certification requirements – What FARs are applicable? Installation detail – what is being modified? Prototype installation – What is new? Functional hazard Assessment (FHA) – is it safe? EZAP-EWIS Requirements – Any aging aircraft issues? Certification Data – How is compliance achieved? Delegation and FAA involvement – Who is doing the work? Proposed certification schedule – When is the installation? Certification documentation – What the FAA Expects to see Cabin Systems Certification Concerns In addition to meeting the requirements for DO-160, Cabin System Certification needs to address issues related to: Power management: Generally, IFE and Wi-Fi Systems are classified as “Non-Essential Equipment” from a certification viewpoint. Connected to “non-essential” power buses Must be able to shed IFE & Wi-Fi Systems in a smoke/fire event or Other electrical emergency (FAA Policy 00-111-160) FAA is more relaxed with testing wi-fi. It used to be that you had to have 150 seats with laptops running wi-fi, but now it is down to around 50. Aging aircraft concerns – electrical and structural Issue papers addressing technical concerns involving: “Structural Certification Criteria for Large Antenna Installations” Antenna “Vibration/Buffeting Compliance Criteria” DO-160 : Environmental Test Procedures DO 160 – “Environmental Conditions and Test Procedures for Airborne Equipment”, Issued by RTCA Provides guidance to equipment manufacturers as to testing requirements Temperature: –40C to +55C Vibration and Shock Contaminant susceptibility – fluids and dust Electro-magnetic Interference Cabin systems are generally classified as “non-essential” Swissair 111 crashed (in part) due to non-standard wiring practices. EWIS Design Implications Installation design must take EWIS Requirements into account. This generally means: Aircraft surveys are needed to identify proper wire routing Ensure existing wiring diagrams are correct Identify primary/Secondary/Tertiary bus locations Verify proper separation of wire bundles exist Required separation from fuel quantity indicator system (FQIS) to prevent fuel tang ignition Enhanced Zonal Analysis Procedure (EZAP) Performed EZAP was developed by the Aging Transport Systems Rulemaking Advisory Committee (ATSRAC) EZAP is the method for analyzing airplane zones with an emphasis on evaluating wiring systems and the existence of combustibles  in the cabin. Certification Considerations for Wi-Fi Systems Electrical – All existing DO 160 testing required Issue papers required Onboard EMI testing – any interference with aircraft systems when multiple wi-fi users are logged on? Vibration/Buffeting compliance criteria – what is the effect of the antenna on aircraft flight characteristics? Structural certification criteria – what are the stress loads on the aircraft at the antenna location and what is the impact on maintenance inspection criteria for the airline? Damage tolerance analysis required Goal – minimize maintenance inspection intervals

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• Build 2012, the first post

  - by Dennis Vroegop

  Yes, I was one of the lucky few who made it to Build. Build, formerly known as the Professional Developers Conference (or PDC) is the place to be if you are a developer on the Microsoft platform. Since I take my job seriously I took out some time on my busy schedule, sighed at the thought of not seeing my family for another week and signed up for it. Now, before I talk about the amazing Surface devices (yes, this posting is written on one of them), the great Lumia 920 we all got, the long deserved love for touch, NUI and other things I have been talking about for years, I need to do some ranting. So if you are anxious to read about the technical goodies you’ll have to wait until the next post. Still here? Good. When I signed up for the Build conference during my holidays this summer it was pretty obvious that demand would be high. Therefor I made sure I was on time. But even though I registered only 7 minutes after the initial opening time the Early Bird discount for the first 500 attendees was already sold out. I later learned that registration actually started 5 minutes before the scheduled time but even though it is still impressive how fast things went. The whole event sold out in 57 minutes Or so they say… A lot of people got put on the waiting list. There was room for about 1500 attendees and I heard that at least 1000 people were on that waiting list, including a lot of people I know. Strangely, all of them got tickets assigned after 2 weeks. Here at the conference I heard from a guy from Nokia that they had shipped 2500 Lumia 920 phones. That number matches the rumors that the organization added 1000 extra tickets. This, of course is no problem. I am not an elitist and I think large crowds have a special atmosphere that I quite like. But…. The Microsoft Campus is not equipped for that sheer volume of visitors. That was painfully obvious during on-site registration where people had to stand in line for over 2 hours. The conference is spread out over 2 buildings, divided by a 15 minute busride (yes, the campus is that big). I have seen queues of over 200 people waiting for the bus and when that arrived it had a capacity of 16. I can assure you: that doesn’t fit. This of course means that travelling from one site to the other might take about 30 minutes. So you arrive at the session room just in time, only to find out it’s full. Since you can’ get into that session you try to find another one but now you’re even more late so you have no chance at all of entering. The doors are closed and you’re told: “Well, you can watch the live stream online”. Mmmm… So I spend thousands of dollars, a week away from home, family and work to be told I can also watch the sessions online? Are you fricking kidding me? I could go on but I won’t. You get the idea. It’s jus badly organized, something I am not really used to in my 20 years of experience at Microsoft events. Yes, I am disappointed. I hope a lot of people here in Redmond will also fill in the evals and that the organization next year will do a better job. Really, Build deserves better. </rantmode>

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• The Future of Air Travel: Intelligence and Automation

  - by BobEvans

  Remember those white-knuckle flights through stormy weather where unexpected plunges in altitude result in near-permanent relocations of major internal organs? Perhaps there’s a better way, according to a recent Wall Street Journal article: “Pilots of a Honeywell International Inc. test plane stayed on their initial flight path, relying on the company's latest onboard radar technology to steer through the worst of the weather. The specially outfitted Boeing 757 barely shuddered as it gingerly skirted some of the most ferocious storm cells over Fort Walton Beach and then climbed above the rest in zero visibility.” Or how about the multifaceted check-in process, which might not wreak havoc on liver location but nevertheless makes you wonder if you’ve been trapped in some sort of covert psychological-stress test? Another WSJ article, called “The Self-Service Airport,” says there’s reason for hope there as well: “Airlines are laying the groundwork for the next big step in the airport experience: a trip from the curb to the plane without interacting with a single airline employee. At the airport of the near future, ‘your first interaction could be with a flight attendant,’ said Ben Minicucci, chief operating officer of Alaska Airlines, a unit of Alaska Air Group Inc.” And in the topsy-turvy world of air travel, it’s not just the passengers who’ve been experiencing bumpy rides: the airlines themselves are grappling with a range of challenges—some beyond their control, some not—that make profitability increasingly elusive in spite of heavy demand for their services. A recent piece in The Economist illustrates one of the mega-challenges confronting the airline industry via a striking set of contrasting and very large numbers: while the airlines pay $7 billion per year to third-party computerized reservation services, the airlines themselves earn a collective profit of only $3 billion per year. In that context, the anecdotes above point unmistakably to the future that airlines must pursue if they hope to be able to manage some of the factors outside of their control (e.g., weather) as well as all of those within their control (operating expenses, end-to-end visibility, safety, load optimization, etc.): more intelligence, more automation, more interconnectedness, and more real-time awareness of every facet of their operations. Those moves will benefit both passengers and the air carriers, says the WSJ piece on The Self-Service Airport: “Airlines say the advanced technology will quicken the airport experience for seasoned travelers—shaving a minute or two from the checked-baggage process alone—while freeing airline employees to focus on fliers with questions. ‘It's more about throughput with the resources you have than getting rid of humans,’ said Andrew O'Connor, director of airport solutions at Geneva-based airline IT provider SITA.” Oracle’s attempting to help airlines gain control over these challenges by blending together a range of its technologies into a solution called the Oracle Airline Data Model, which suggests the following steps: • To retain and grow their customer base, airlines need to focus on the customer experience. • To personalize and differentiate the customer experience, airlines need to effectively manage their passenger data. • The Oracle Airline Data Model can help airlines jump-start their customer-experience initiatives by consolidating passenger data into a customer data hub that drives realtime business intelligence and strategic customer insight. • Oracle’s Airline Data Model brings together multiple types of data that can jumpstart your data-warehousing project with rich out-of-the-box functionality. • Oracle’s Intelligent Warehouse for Airlines brings together the powerful capabilities of Oracle Exadata and the Oracle Airline Data Model to give you real-time strategic insights into passenger demand, revenues, sales channels and your flight network. The airline industry aside, the bullet points above offer a broad strategic outline for just about any industry because the customer experience is becoming pre-eminent in each and there is simply no way to deliver world-class customer experiences unless a company can capture, manage, and analyze all of the relevant data in real-time. I’ll leave you with two thoughts from the WSJ article about the new in-flight radar system from Honeywell: first, studies show that a single episode of serious turbulence can wrack up $150,000 in additional costs for an airline—so, it certainly behooves the carriers to gain the intelligence to avoid turbulence as much as possible. And second, it’s back to that top-priority customer-experience thing and the value that ever-increasing levels of intelligence can deliver. As the article says: “In the cabin, reporters watched screens showing the most intense parts of the nearly 10-mile wide storm, which churned some 7,000 feet below, in vibrant red and other colors. The screens also were filled with tiny symbols depicting likely locations of lightning and hail, which can damage planes and wreak havoc on the nerves of white-knuckle flyers.”  (Bob Evans is senior vice-president, communications, for Oracle.)  

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• Columnstore Case Study #1: MSIT SONAR Aggregations

  - by aspiringgeek

  Preamble This is the first in a series of posts documenting big wins encountered using columnstore indexes in SQL Server 2012 & 2014.  Many of these can be found in this deck along with details such as internals, best practices, caveats, etc.  The purpose of sharing the case studies in this context is to provide an easy-to-consume quick-reference alternative. Why Columnstore? If we’re looking for a subset of columns from one or a few rows, given the right indexes, SQL Server can do a superlative job of providing an answer. If we’re asking a question which by design needs to hit lots of rows—DW, reporting, aggregations, grouping, scans, etc., SQL Server has never had a good mechanism—until columnstore. Columnstore indexes were introduced in SQL Server 2012. However, they're still largely unknown. Some adoption blockers existed; yet columnstore was nonetheless a game changer for many apps.  In SQL Server 2014, potential blockers have been largely removed & they're going to profoundly change the way we interact with our data.  The purpose of this series is to share the performance benefits of columnstore & documenting columnstore is a compelling reason to upgrade to SQL Server 2014. App: MSIT SONAR Aggregations At MSIT, performance & configuration data is captured by SCOM. We archive much of the data in a partitioned data warehouse table in SQL Server 2012 for reporting via an application called SONAR.  By definition, this is a primary use case for columnstore—report queries requiring aggregation over large numbers of rows.  New data is refreshed each night by an automated table partitioning mechanism—a best practices scenario for columnstore. The Win Compared to performance using classic indexing which resulted in the expected query plan selection including partition elimination vs. SQL Server 2012 nonclustered columnstore, query performance increased significantly.  Logical reads were reduced by over a factor of 50; both CPU & duration improved by factors of 20 or more.  Other than creating the columnstore index, no special modifications or tweaks to the app or databases schema were necessary to achieve the performance improvements.  Existing nonclustered indexes were rendered superfluous & were deleted, thus mitigating maintenance challenges such as defragging as well as conserving disk capacity. Details The table provides the raw data & summarizes the performance deltas. Logical Reads (8K pages) CPU (ms) Durn (ms) Columnstore 160,323 20,360 9,786 Conventional Table & Indexes 9,053,423 549,608 193,903 ? x56 x27 x20 The charts provide additional perspective of this data.  "Conventional vs. Columnstore Metrics" document the raw data.  Note on this linear display the magnitude of the conventional index performance vs. columnstore.  The “Metrics (?)” chart expresses these values as a ratio. Summary For DW, reports, & other BI workloads, columnstore often provides significant performance enhancements relative to conventional indexing.  I have documented here, the first in a series of reports on columnstore implementations, results from an initial implementation at MSIT in which logical reads were reduced by over a factor of 50; both CPU & duration improved by factors of 20 or more.  Subsequent features in this series document performance enhancements that are even more significant. 

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• When row estimation goes wrong

  - by Dave Ballantyne

  Whilst working at a client site, I hit upon one of those issues that you are not sure if that this is something entirely new or a bug or a gap in your knowledge. The client had a large query that needed optimizing.  The query itself looked pretty good, no udfs, UNION ALL were used rather than UNION, most of the predicates were sargable other than one or two minor ones.  There were a few extra joins that could be eradicated and having fixed up the query I then started to dive into the plan. I could see all manor of spills in the hash joins and the sort operations,  these are caused when SQL Server has not reserved enough memory and has to write to tempdb.  A VERY expensive operation that is generally avoidable.  These, however, are a symptom of a bad row estimation somewhere else, and when that bad estimation is combined with other estimation errors, chaos can ensue. Working my way back down the plan, I found the cause, and the more I thought about it the more i came convinced that the optimizer could be making a much more intelligent choice. First step is to reproduce and I was able to simplify the query down a single join between two tables, Product and ProductStatus,  from a business point of view, quite fundamental, find the status of particular products to show if ‘active’ ,’inactive’ or whatever. The query itself couldn’t be any simpler The estimated plan looked like this: Ignore the “!” warning which is a missing index, but notice that Products has 27,984 rows and the join outputs 14,000. The actual plan shows how bad that estimation of 14,000 is : So every row in Products has a corresponding row in ProductStatus.  This is unsurprising, in fact it is guaranteed,  there is a trusted FK relationship between the two columns.  There is no way that the actual output of the join can be different from the input. The optimizer is already partly aware of the foreign key meta data, and that can be seen in the simplifiction stage. If we drop the Description column from the query: the join to ProductStatus is optimized out. It serves no purpose to the query, there is no data required from the table and the optimizer knows that the FK will guarantee that a matching row will exist so it has been removed. Surely the same should be applied to the row estimations in the initial example, right ?  If you think so, please upvote this connect item. So what are our options in fixing this error ? Simply changing the join to a left join will cause the optimizer to think that we could allow the rows not to exist. or a subselect would also work However, this is a client site, Im not able to change each and every query where this join takes place but there is a more global switch that will fix this error,  TraceFlag 2301. This is described as, perhaps loosely, “Enable advanced decision support optimizations”. We can test this on the original query in isolation by using the “QueryTraceOn” option and lo and behold our estimated plan now has the ‘correct’ estimation. Many thanks goes to Paul White (b|t) for his help and keeping me sane through this

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• Move on and look elsewhere, or confront the boss?

  - by Meister

  Background: I have my Associates in Applied Science (Comp/Info Tech) with a strong focus in programming, and I'm taking University classes to get my Bachelors. I was recently hired at a local company to be a Software Engineer I on a team of about 8, and I've been told they're looking to hire more. This is my first job, and I was offered what I feel to be an extremely generous starting salary ($30/hr essentially + benefits and yearly bonus). What got me hired was my passion for programming and a strong set of personal projects. Problem: I had no prior experience when I interviewed, so I didn't know exactly what to ask them about the company when I was hired. I've spotted a number of warning signs and annoyances since then, such as: Four developers when I started, with everyone talking about "Ben" or "Ryan" leaving. One engineer hired thirty days before me, one hired two weeks after me. Most of the department has been hiring a large number of people since I started. Extremely limited internet access. I understand the idea from an IT point of view, but not only is Facebook blocked, but so it Youtube, Twitter, and Pandora. I've also figured out that they block all access to non-DNS websites (http://xxx.xxx.xxx.xxx/) and strangely enough Miranda-IM. Low cubicles. Which is fine because I like my immediate coworkers, but they put the developers with the customer service, customer training, and QA department in a huge open room. Noise, noise, noise, and people stop to chitchat all day long. Headphones only go so far. Several emails have been sent out by my boss since I started telling us programmers to not talk about non-work-related-things like Video Games at our cubicles, despite us only spending maybe five minutes every few hours doing so. Further digging tells me that this is because someone keeps complaining that the programmers are "slacking off". People are looking over my shoulder all day. I was in the Freenode webchat to get help with a programming issue, and within minutes I had an email from my boss (to all the developers) telling us that we should NOT be connected to any outside chat servers at work. Version control system from 2005 that we must access with IE and keep the Java 1.4 JRE installed to be able to use. I accidentally updated to Java 6 one day and spent the next two days fighting with my PC to undo this "problem". No source control, no comments on anything, no standards, no code review, no unit testing, no common sense. I literally found a problem in how they handle string resource translations that stems from the simple fact that they don't trim excess white spaces, leading to developers doing: getResource("Date: ") instead of: getResource("Date") + ": ", and I was told to just add the excess white spaces back to the database instead of dealing with the issue directly. Some of these things I'd like to try to understand, but I like having IRC open to talk in a few different rooms during the day and keep in touch with friends/family over IM. They don't break my concentration (not NEARLY as much as the lady from QA stopping by to talk about her son), but because people are looking over my shoulder all day as they walk by they complain when they see something that's not "programmer-looking work". I've been told by my boss and QA that I do good, fast work. I should be judged on my work output and quality, not what I have up on my screen for the five seconds you're walking by So, my question is, even though I'm just barely at my 90 days: How do you decide to move on from a job and looking elsewhere, or when you should start working with your boss to resolve these issues? Is it even possible to get the boss to work with me in many of these things? This is the only place I heard back from even though I sent out several resume's a day for several months, and this place does pay well for putting up with their many flaws, but I'm just starting to get so miserable working here already. Should I just put up with it?

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• how to write the code for this program specially in mathematica? [closed]

  - by asd

  I implemented a solution to the problem below in Mathematica, but it takes a very long time (hours) to compute f of kis or the set B for large numbers. Somebody suggested that implementing this in C++ resulted in a solution in less than 10 minutes. Would C++ be a good language to learn to solve these problems, or can my Mathematica code be improved to fix the performance issues? I don't know anything about C or C++ and it should be difficult to start to learn this languages. I prefer to improve or write new code in mathematica. Problem Description Let $f$ be an arithmetic function and A={k1,k2,...,kn} are integers in increasing order. Now I want to start with k1 and compare f(ki) with f(k1). If f(ki)f(k1), put ki as k1. Now start with ki, and compare f(kj) with f(ki), for ji. If f(kj)f(ki), put kj as ki, and repeat this procedure. At the end we will have a sub sequence B={L1,...,Lm} of A by this property: f(L(i+1))f(L(i)), for any 1<=i<=m-1 For example, let f is the divisor function of integers. Here I put some part of my code and this is just a sample and the question in my program could be more larger than these: «««««««««««««««««««««««««««««««««««« f[n_] := DivisorSigma[0, n]; g[n_] := Product[Prime[i], {i, 1, PrimePi[n]}]; k1 = g[67757] g[353] g[59] g[19] g[11] g[7] g[5]^2 6^3 2^7; k2 = g[67757] g[353] g[59] g[19] g[11] g[7] g[5] 6^5 2^7; k3 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5] 6^4 2^7; k4 = g[67759] g[349] g[53] g[19] g[11] g[7] g[5] 6^5 2^6; k5 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5] 6^4 2^8; k6 = g[67759] g[349] g[53] g[19] g[11] g[7] g[5]^2 6^3 2^7; k7 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5] 6^5 2^6; k8 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5] 6^4 2^9; k9 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5]^2 6^3 2^7; k10 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5] 6^5 2^7; k11 = g[67759] g[349] g[53] g[19] g[11] g[7] g[5]^2 6^4 2^6; k12 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5]^2 6^3 2^8; k13 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5]^2 6^4 2^6; k14 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5]^2 6^3 2^9; k15 = g[67757] g[359] g[53] g[19] g[11] g[7] g[5]^2 6^4 2^7; k16 = g[67757] g[359] g[53] g[23] g[11] g[7] g[5] 6^4 2^8; k17 = g[67757] g[359] g[59] g[19] g[11] g[7] g[5] 6^4 2^7; k18 = g[67757] g[359] g[53] g[23] g[11] g[7] g[5] 6^4 2^9; k19 = g[67759] g[353] g[53] g[19] g[11] g[7] g[5] 6^4 2^6; k20 = g[67763] g[347] g[53] g[19] g[11] g[7] g[5] 6^4 2^7; k = Table[k1, k2, k3, k4, k5, k6, k7, k8, k9, k10, k11, k12, k13, k14, k15, k16, k17, k18, k19, k20]; i = 1; count = 0; For[j = i, j <= 20, j++, If[f[k[[j]]] - f[k[[i]]] > 0, i = j; Print["k",i]; count = count + 1]]; Print["count= ", count] ««««««««««««««««««««««««««««««««««««

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• Need help partitioning when reinstalling Ubuntu 14.04

  - by Chris M.

  I upgraded to 14.04 about a month ago on my HP Mini netbook (about 16 GB hard disk). A few days ago the system crashed (I don't know why but I was using internet at the time). When I restarted the computer, Ubuntu would not load. Instead, I got a message from the BIOS saying Reboot and Select proper Boot device or Insert Boot Media in selected Boot device and press a key I took this to mean that I needed to reinstall 14.04. When I try to reinstall Ubuntu from the USB stick, I choose "Erase disk and install Ubuntu" but then I get a message: Some of the partitions you created are too small. Please make the following partitions at least this large: / 3.3 GB If you do not go back to the partitioner and increase the size of these partitions, the installation may fail. At first I hit Continue to see if it would install anyway, and it gave the message: The attempt to mount a file system with type ext4 in SCSI1 (0,0,0), partition # 1 (sda) at / failed. You may resume partitioning from the partitioning menu. The second time I hit Go Back, and it took me to the following partitioning table: Device Type Mount Point Format Size Used System /dev/sda /dev/sda1 ext4 (checked) 3228 MB Unknown /dev/sda5 swap (not checked) 1063 MB Unknown + - Change New Partition Table... Revert Device for boot loader installation: /dev/sda ATA JM Loader 001 (4.3 GB) At this point I'm not sure what to do. I've never partitioned my hard drive before and I don't want to screw things up. (I'm not particularly tech savvy.) Can you instruct me what I should do. (P.S. I'm afraid the table might not appear as I typed it in.) Results from fdisk: ubuntu@ubuntu:~$ sudo fdisk -l Disk /dev/sda: 4294 MB, 4294967296 bytes 255 heads, 63 sectors/track, 522 cylinders, total 8388608 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Disk /dev/sda doesn't contain a valid partition table Disk /dev/sdb: 7860 MB, 7860125696 bytes 155 heads, 31 sectors/track, 3194 cylinders, total 15351808 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0009a565 Device Boot Start End Blocks Id System /dev/sdb1 * 2768 15351807 7674520 b W95 FAT32 ubuntu@ubuntu:~$ Here is what it displays when I open the Disks utility (I tried the screenshot terminal command you suggested but it didn't seem to do anything): 4.3 GB Hard Disk /dev/sda Model: JM Loader 001 (01000001) Size: 4.3 GB (4,294,967,296 bytes) Serial Number: 01234123412341234 Assessment: SMART is not supported Volumes Size: 4.3 GB (4,294,967,296 bytes) Device: /dev/sda Contents: Unknown (There is a button in the utility that when you click it gives the following options: Format... Create Disk Image... Restore Disk Image... Benchmark but SMART Data & Self-Tests... is dimmed out) When I hit F9 Change Boot Device Order, it shows the hard drive as: SATA:PM-JM Loader 001 When I hit F10 to get me into the BIOS Setup Utility, under Diagnostic it shows: Primary Hard Disk Self Test Not Support NetworkManager Tool State: disconnected Device: eth0 Type: Wired Driver: atl1c State: unavailable Default: no HW Address: 00:26:55:B0:7F:0C Capabilities: Carrier Detect: yes Wired Properties Carrier: off When I run command lshw -C network, I get: WARNING: you should run this program as super-user. *-network description: Network controller product: BCM4312 802.11b/g LP-PHY vendor: Broadcom Corporation physical id: 0 bus info: pci@0000:01:00.0 version: 01 width: 64 bits clock: 33MHz capabilities: bus_master cap_list configuration: driver=b43-pci-bridge latency=0 resources: irq:16 memory:feafc000-feafffff *-network description: Ethernet interface product: AR8132 Fast Ethernet vendor: Qualcomm Atheros physical id: 0 bus info: pci@0000:02:00.0 logical name: eth0 version: c0 serial: 00:26:55:b0:7f:0c capacity: 100Mbit/s width: 64 bits clock: 33MHz capabilities: bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=atl1c driverversion=1.0.1.1-NAPI latency=0 link=no multicast=yes port=twisted pair resources: irq:43 memory:febc0000-febfffff ioport:ec80(size=128) WARNING: output may be incomplete or inaccurate, you should run this program as super-user.

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• Caching factory design

  - by max

  I have a factory class XFactory that creates objects of class X. Instances of X are very large, so the main purpose of the factory is to cache them, as transparently to the client code as possible. Objects of class X are immutable, so the following code seems reasonable: # module xfactory.py import x class XFactory: _registry = {} def get_x(self, arg1, arg2, use_cache = True): if use_cache: hash_id = hash((arg1, arg2)) if hash_id in _registry: return _registry[hash_id] obj = x.X(arg1, arg2) _registry[hash_id] = obj return obj # module x.py class X: # ... Is it a good pattern? (I know it's not the actual Factory Pattern.) Is there anything I should change? Now, I find that sometimes I want to cache X objects to disk. I'll use pickle for that purpose, and store as values in the _registry the filenames of the pickled objects instead of references to the objects. Of course, _registry itself would have to be stored persistently (perhaps in a pickle file of its own, in a text file, in a database, or simply by giving pickle files the filenames that contain hash_id). Except now the validity of the cached object depends not only on the parameters passed to get_x(), but also on the version of the code that created these objects. Strictly speaking, even a memory-cached object could become invalid if someone modifies x.py or any of its dependencies, and reloads it while the program is running. So far I ignored this danger since it seems unlikely for my application. But I certainly cannot ignore it when my objects are cached to persistent storage. What can I do? I suppose I could make the hash_id more robust by calculating hash of a tuple that contains arguments arg1 and arg2, as well as the filename and last modified date for x.py and every module and data file that it (recursively) depends on. To help delete cache files that won't ever be useful again, I'd add to the _registry the unhashed representation of the modified dates for each record. But even this solution isn't 100% safe since theoretically someone might load a module dynamically, and I wouldn't know about it from statically analyzing the source code. If I go all out and assume every file in the project is a dependency, the mechanism will still break if some module grabs data from an external website, etc.). In addition, the frequency of changes in x.py and its dependencies is quite high, leading to heavy cache invalidation. Thus, I figured I might as well give up some safety, and only invalidate the cache only when there is an obvious mismatch. This means that class X would have a class-level cache validation identifier that should be changed whenever the developer believes a change happened that should invalidate the cache. (With multiple developers, a separate invalidation identifier is required for each.) This identifier is hashed along with arg1 and arg2 and becomes part of the hash keys stored in _registry. Since developers may forget to update the validation identifier or not realize that they invalidated existing cache, it would seem better to add another validation mechanism: class X can have a method that returns all the known "traits" of X. For instance, if X is a table, I might add the names of all the columns. The hash calculation will include the traits as well. I can write this code, but I am afraid that I'm missing something important; and I'm also wondering if perhaps there's a framework or package that can do all of this stuff already. Ideally, I'd like to combine in-memory and disk-based caching.

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• Recieving and organizing results without server side script (JavaScript)

  - by Aaron

  I have been working on a very large form project for the past few days. I finally managed to get tables to work properly within a javascript file that opens a new display window. Now the issue at hand is that I can't seem to get CSS code to work within the javascript that I have created. Before everyone starts thinking "just use server side script idiot" I have a few conditions and info about the file: The file is only being ran local due to confidential information risks. Once again no option for server access. The intranet the computers are on are already top security and this wouldn't exactly be a company wide program The code below is obviously just a demo with a simple form... The real file has six pages of highly confidential information Only certain fields on this form will actually be gathered (example: address doesnt appear in the results) The display page will contain data compiled into tables for easier viewing I need to be able to create css commands to easily detect certain information if it applies and along with matching design of the original form Here is the code: <html> <head> <title>Form Example</title> <script LANGUAGE="JavaScript" type="text/javascript"> function display() { DispWin = window.open('','NewWin', 'toolbar=no,status=no,width=800,height=600') message = "<body>"; message += "<table border=1 width=100%>"; message += "<tr>"; message += "<th colspan=2 align=center><font face=stencil color=black><h1>Results</h1><h4>one</h4></font>"; message += "</th>"; message += "</tr>"; message += "<td width=50% align=left>"; message += "<ul><li><b><font face=calibri color=red>NAME:</font></b> " + document.form1.yourname.value + "</UL>" message += "</td>"; message += "<td width=50% align=left>"; message += "<li><b>PHONE: </b>" + document.form1.phone.value + "</ul>"; message += "</td>"; message += "</table>"; message += "<body>"; DispWin.document.write(message); DispWin.document.body.style.cssText = 'color:#blue;'; } </script> </head> <body> <h1>Form Example</h1> Enter the following information: <form name="form1"> <p><b>Name:</b> <input TYPE="TEXT" SIZE="20" NAME="yourname"> </p> <p><b>Address:</b> <input TYPE="TEXT" SIZE="30" NAME="address"> </p> <p><b>Phone: </b> <input TYPE="TEXT" SIZE="15" NAME="phone"> </p> <p><input TYPE="BUTTON" VALUE="Display" onClick="display();"></p> </form> </body> </html> >

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• Essbase BSO Data Fragmentation

  - by Ann Donahue

  Essbase BSO Data Fragmentation Data fragmentation naturally occurs in Essbase Block Storage (BSO) databases where there are a lot of end user data updates, incremental data loads, many lock and send, and/or many calculations executed.  If an Essbase database starts to experience performance slow-downs, this is an indication that there may be too much fragmentation.  See Chapter 54 Improving Essbase Performance in the Essbase DBA Guide for more details on measuring and eliminating fragmentation: http://docs.oracle.com/cd/E17236_01/epm.1112/esb_dbag/daprcset.html Fragmentation is likely to occur in the following situations: Read/write databases that users are constantly updating data Databases that execute calculations around the clock Databases that frequently update and recalculate dense members Data loads that are poorly designed Databases that contain a significant number of Dynamic Calc and Store members Databases that use an isolation level of uncommitted access with commit block set to zero There are two types of data block fragmentation Free space tracking, which is measured using the Average Fragmentation Quotient statistic. Block order on disk, which is measured using the Average Cluster Ratio statistic. Average Fragmentation Quotient The Average Fragmentation Quotient ratio measures free space in a given database.  As you update and calculate data, empty spaces occur when a block can no longer fit in its original space and will either append at the end of the file or fit in another empty space that is large enough.  These empty spaces take up space in the .PAG files.  The higher the number the more empty spaces you have, therefore, the bigger the .PAG file and the longer it takes to traverse through the .PAG file to get to a particular record.  An Average Fragmentation Quotient value of 3.174765 means the database is 3% fragmented with free space. Average Cluster Ratio Average Cluster Ratio describes the order the blocks actually exist in the database. An Average Cluster Ratio number of 1 means all the blocks are ordered in the correct sequence in the order of the Outline.  As you load data and calculate data blocks, the sequence can start to be out of order.  This is because when you write to a block it may not be able to place back in the exact same spot in the database that it existed before.  The lower this number the more out of order it becomes and the more it affects performance.  An Average Cluster Ratio value of 1 means no fragmentation.  Any value lower than 1 i.e. 0.01032828 means the data blocks are getting further out of order from the outline order. Eliminating Data Block Fragmentation Both types of data block fragmentation can be removed by doing a dense restructure or export/clear/import of the data.  There are two types of dense restructure: 1. Implicit Restructures Implicit dense restructure happens when outline changes are done using EAS Outline Editor or Dimension Build. Essbase restructures create new .PAG files restructuring the data blocks in the .PAG files. When Essbase restructures the data blocks, it regenerates the index automatically so that index entries point to the new data blocks. Empty blocks are NOT removed with implicit restructures. 2. Explicit Restructures Explicit dense restructure happens when a manual initiation of the database restructure is executed. An explicit dense restructure is a full restructure which comprises of a dense restructure as outlined above plus the removal of empty blocks Empty Blocks vs. Fragmentation The existence of empty blocks is not considered fragmentation.  Empty blocks can be created through calc scripts or formulas.  An empty block will add to an existing database block count and will be included in the block counts of the database properties.  There are no statistics for empty blocks.  The only way to determine if empty blocks exist in an Essbase database is to record your current block count, export the entire database, clear the database then import the exported data.  If the block count decreased, the difference is the number of empty blocks that had existed in the database.

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