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  • Where should instantiated classes be stored?

    - by Eric C.
    I'm having a bit of a design dilemma here. I'm writing a library that consists of a bunch of template classes that are designed to be used as a base for creating content. For example: public class Template { public string Name {get; set;} public string Description {get; set;} public string Attribute1 {get; set;} public string Attribute2 {get; set;} public Template() { //constructor } public void DoSomething() { //does something } ... } The problem is, not only is the library providing the templates, it will also supply quite a few predefined templates which are instances of these template classes. The question is, where do I put these instances of the templates? The three solutions I've come up with so far are: 1) Provide serialized instances of the templates as files. On the one hand, this solution would keep the instances separated from the library itself, which is nice, but it would also potentially add complexity for the user. Even if we provided methods for loading/deserializing the files, they'd still have to deal with a bunch of files, and some kind of config file so the app knows where to look for those files. Plus, creating the template files would probably require a separate app, so if the user wanted to stick with the files method of storing templates, we'd have to provide some kind of app for creating the template files. Also, this requires external dependencies for testing the templates in the user's code. 2) Add readonly instances to the template class Example: public class Template { public string Name {get; set;} public string Description {get; set;} public string Attribute1 {get; set;} public string Attribute2 {get; set;} public Template PredefinedTemplate { get { Template templateInstance = new Template(); templateInstance.Name = "Some Name"; templateInstance.Description = "A description"; ... return templateInstance; } } public Template() { //constructor } public void DoSomething() { //does something } ... } This method would be convenient for users, as they would be able to access the predefined templates in code directly, and would be able to unit test code that used them. The drawback here is that the predefined templates pollute the Template type namespace with a bunch of extra stuff. I suppose I could put the predefined templates in a different namespace to get around this drawback. The only other problem with this approach is that I'd have to basically duplicate all the namespaces in the library in the predefined namespace (e.g. Templates.SubTemplates and Predefined.Templates.SubTemplates) which would be a pain, and would also make refactoring more difficult. 3) Make the templates abstract classes and make the predefined templates inherit from those classes. For example: public abstract class Template { public string Name {get; set;} public string Description {get; set;} public string Attribute1 {get; set;} public string Attribute2 {get; set;} public Template() { //constructor } public void DoSomething() { //does something } ... } and public class PredefinedTemplate : Template { public PredefinedTemplate() { this.Name = "Some Name"; this.Description = "A description"; this.Attribute1 = "Some Value"; ... } } This solution is pretty similar to #2, but it ends up creating a lot of classes that don't really do anything (none of our predefined templates are currently overriding behavior), and don't have any methods, so I'm not sure how good a practice this is. Has anyone else had any experience with something like this? Is there a best practice of some kind, or a different/better approach that I haven't thought of? I'm kind of banging my head against a wall trying to figure out the best way to go. Thanks!

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  • Get More Value From Your Oracle Premier Support Investment

    - by Get Proactive Customer Adoption Team
    Untitled Document The Return on Investment in Support Training I’m a typical software user. I’ve been using spreadsheets almost daily for the past 10 years or so. I know how to enter simple formulas, format cells, import files, and I can sort and filter. Sometimes I even use a pivot table. I never attended training. I learnt everything I know on the fly. Sometimes it was intuitive and easy, other times I had to spend minutes and even hours searching for a solution. Yet when I see what some other people can do with their spreadsheets, I know I’m utilizing maybe 15% of the functionality. Pity, one day I really have to sign up for training. Why haven’t I done it yet? Ah, you know, I’m a busy person, I have work to do. And if I need to use a feature that I am unfamiliar with, I’ll spend time on it only when I really need it. Now wait. When I recall how much time I spent trying to figure how things work compared to time I spent doing the productive work, I realize it was not insignificant. I’m unable to sum up all the time I spent ‘learning’ on the fly, but I’m sure it’s been days or even weeks. And after all this time, I’ve mastered 15% of its features. If only I had attended training years ago. That investment would have paid back 10 times! Working with My Oracle Support is no different. Our customers typically use simple search, create service requests, and download patches. They think they know how to use My Oracle Support. And they’re right. They know something but often they’re utilizing only a fragment of My Oracle Support’s potential. For the investment that has been made, using only a small subset of the capabilities offered in My Oracle Support leaves value on the table. There is much more available in My Oracle Support. Dozens of diagnostic tools and proactive health checks will keep verifying your Oracle environments against best practices that Oracle gathers every day thanks to our comprehensive knowledge management process. Automated patch recommendations will help prevent known issues, and upgrade planning and more is included in My Oracle Support. Why are you not utilizing all of these best practices, capabilities and tools? Is it because you don’t have time to invest 2-3 hours of your time to learn about the features? Simply because you think you can learn on the fly like I thought I could? Does learning on the fly how to properly use the Service Request escalation process when you already have critical issue sound like a good idea? My advice is: Invest your time now to learn how My Oracle Support can help you prevent issues on your systems. Learn how to find answers faster and resolve problems more efficiently. Understand how to properly complete a service request. Invest in Support training, offered at no additional cost to Oracle Premier Support customers. It will pay back quicker than you think. It will bring you more value than you think. Discover your advantage with Oracle Premier Support's Proactive Portfolio.

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  • iOS 5 New Features vs Android

    - by kerry
    Browsing through the iOS 5 features list, I can’t help but notice a lot of it is catch up. Having owned both an iPhone and an Android for a considerable amount of time, I figured I would jot down my opinions. Notification Center – Completely ripped off from Android but looks good and is a much needed addition iMessage – This is very interesting as most people who would think it’s cool, probably really wouldn’t understand the significance.  Basically, Apple is adding an IM application to iOS.  Now iPhone / iPad users can sit around messaging each other how cool it is like Crackberry users circa 2003.  I guess the only real improvement over MMS is that you can easily setup groups, see when each other are typing, and don’t incur text messaging charges; at the expense of leaving your non-iOS buddies out (who wants to talk to those losers anyways?). Newstand – An app update and not an OS one (Apple typically doesn’t make distinctions).  It all seems like stuff my current Nook stuff will do.  Note: I did look to compare prices but it seems that information is not available without downloading iTunes.  lame. Reminders – TODO lists are ho hum, but the ability to have reminders when you arrive or leave a position is pretty cool. Twitter integration – The fact that the best Apple can come up with is ‘one at a timing’ online service integration is laughable at best. Camera – Can control it from the lock screen.  Now you’ll have tons of pocket lint photos in your iCloud to go along with the wicked shot of that cheetah that just unexpectedly ran by your apartment. Photos – Speaking of iCloud, all of your devices photos will be synced through it.  That’s cool I guess, not sure if Android will do the same. Safari – What?  You haven’t been reading rss feeds on your device this whole time?  Something tells me you aren’t about to start. PC Free – Finely Apple untethers the iPhone.  What took them so long? Game Center – This should be an interesting service.  Attention Apple fanboys immediately forget how they are blatantly copying Microsoft achievements (at least rename them). Wifi Sync – Just couldn’t cut the cord completely could they?  For what it’s worth, the Zune has been doing this for 5 years now. All in all a pretty big update.  Mostly iCloud.  Mostly keeping up the mobile status quo.  As an Android user, I can’t say there is anything I am envious of.

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  • JEP 124: Enhance the Certificate Revocation-Checking API

    - by smullan
    Revocation checking is the mechanism to determine the revocation status of a certificate. If it is revoked, it is considered invalid and should not be used. Currently as of JDK 7, the PKIX implementation of java.security.cert.CertPathValidator  includes a revocation checking implementation that supports both OCSP and CRLs, the two main methods of checking revocation. However, there are very few options that allow you to configure the behavior. You can always implement your own revocation checker, but that's a lot of work. JEP 124 (Enhance the Certificate Revocation-Checking API) is one of the 11 new security features in JDK 8. This feature enhances the java.security.cert API to support various revocation settings such as best-effort checking, end-entity certificate checking, and mechanism-specific options and parameters. Let's describe each of these in more detail and show some examples. The features are provided through a new class named PKIXRevocationChecker. A PKIXRevocationChecker instance is returned by a PKIX CertPathValidator as follows: CertPathValidator cpv = CertPathValidator.getInstance("PKIX"); PKIXRevocationChecker prc = (PKIXRevocationChecker)cpv.getRevocationChecker(); You can now set various revocation options by calling different methods of the returned PKIXRevocationChecker object. For example, the best-effort option (called soft-fail) allows the revocation check to succeed if the status cannot be obtained due to a network connection failure or an overloaded server. It is enabled as follows: prc.setOptions(Enum.setOf(Option.SOFT_FAIL)); When the SOFT_FAIL option is specified, you can still obtain any exceptions that may have been thrown due to network issues. This can be useful if you want to log this information or treat it as a warning. You can obtain these exceptions by calling the getSoftFailExceptions method: List<CertPathValidatorException> exceptions = prc.getSoftFailExceptions(); Another new option called ONLY_END_ENTITY allows you to only check the revocation status of the end-entity certificate. This can improve performance, but you should be careful using this option, as the revocation status of CA certificates will not be checked. To set more than one option, simply specify them together, for example: prc.setOptions(Enum.setOf(Option.SOFT_FAIL, Option.ONLY_END_ENTITY)); By default, PKIXRevocationChecker will try to check the revocation status of a certificate using OCSP first, and then CRLs as a fallback. However, you can switch the order using the PREFER_CRLS option, or disable the fallback altogether using the NO_FALLBACK option. For example, here is how you would only use CRLs to check the revocation status: prc.setOptions(Enum.setOf(Option.PREFER_CRLS, Option.NO_FALLBACK)); There are also a number of other useful methods which allow you to specify various options such as the OCSP responder URI, the trusted OCSP responder certificate, and OCSP request extensions. However, one of the most useful features is the ability to specify a cached OCSP response with the setOCSPResponse method. This can be quite useful if the OCSPResponse has already been obtained, for example in a protocol that uses OCSP stapling. After you have set all of your preferred options, you must add the PKIXRevocationChecker to your PKIXParameters object as one of your custom CertPathCheckers before you validate the certificate chain, as follows: PKIXParameters params = new PKIXParameters(keystore); params.addCertPathChecker(prc); CertPathValidatorResult result = cpv.validate(path, params); Early access binaries of JDK 8 can be downloaded from http://jdk8.java.net/download.html

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  • Modernizr Rocks HTML5

    - by Laila
    HTML5 is a moving target.  At the moment, we don't know what will be in future versions.  In most circumstances, this really matters to the developer. When you're using Adobe Air, you can be reasonably sure what works, what is there, and what isn't, since you have a version of the browser built-in. With Metro, you can assume that you're going to be using at least IE 10.   If, however,  you are using HTML5 in a web application, then you are going to rely heavily on Feature Detection.  Feature-Detection is a collection of techniques that tell you, via JavaScript, whether the current browser has this feature natively implemented or not Feature Detection isn't just there for the esoteric stuff such as  Geo-location,  progress bars,  <canvas> support,  the new <input> types, Audio, Video, web workers or storage, but is required even for semantic markup, since old browsers make a pigs ear out of rendering this.  Feature detection can't rely just on reading the browser version and inferring from that what works. Instead, you must use JavaScript to check that an HTML5 feature is there before using it.  The problem with relying on the user-agent is that it takes a lot of historical data  to work out what version does what, and, anyway, the user-agent can be, and sometimes is, spoofed. The open-source library Modernizr  is just about the most essential  JavaScript library for anyone using HTML5, because it provides APIs to test for most of the CSS3 and HTML5 features before you use them, and is intelligent enough to alter semantic markup into 'legacy' 'markup  using shims  on page-load  for old browsers. It also allows you to check what video Codecs are installed for playing video. It also provides media queries  and conditional resource-loading (formerly YepNope.js.).  Generally, Modernizr gives you the choice of what you do about browsers that don't support the feature that you want. Often, the best choice is graceful degradation, but the resource-loading feature allows you to dynamically load JavaScript Shims to replace the standard API for missing or defective HTML5 functionality, called 'PolyFills'.  As the Modernizr site says 'Yes, not only can you use HTML5 today, but you can use it in the past, too!' The evolutionary progress of HTML5  requires a more defensive style of JavaScript programming where the programmer adopts a mindset of fearing the worst ( IE 6)  rather than assuming the best, whilst exploiting as many of the new HTML features as possible for the requirements of the site or HTML application.  Why would anyone want the distraction of developing their own techniques to do this when  Modernizr exists to do this for you? Laila

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  • Cannot get ATI Drivers installed

    - by bittoast67
    I am trying to install the Catalyst driver. The best I can get is a strange resolution problem and firefox acts all wonkt. The worst I have gotten is low graphics mode in which I just reinstall Ubuntu. I have a HP Pavilion Dv7 laptop. With Radeon 3200 HD. I plan to try again with a fresh install of Ubuntu 12.4.3 as I have heard its the most compatible. This is what I have done: I have tried just the easy way of going to synaptic and installing the drivers that way. the fglrx package (not the fglrx update). And if memory serves I think that boots me into low graphics mode. So, fresh install of Ubuntu and tried again. I have done everything a couple times from this site (http://wiki.cchtml.com/index.php/Ubuntu_Precise_Installation_Guide) following every instruction to a T. That gets me something, such as a lowered fan speed and a much cooler computer, but I also lose most of my resolution. And displays says its the best resolution I can get. I also have a very screwy firefox. Using this method I can see AMD Catalyst Control Center in my dash (two of them really one administrator and one not) but when I try to open it it says no amd driver detected. So again, ubuntu reinstall. I have tried the GUI method from the Legacy driver I got from AMD's site. It runs through smoothly and at the very end after I exit the installer it gives me an error. I have also tried various other methods using terminal, as well as various different drivers (the one from the amd's site and the one suggested in the above link for my graphics card) both to no avail. When I try the method in the link on number 2, and I get the super low res and screwy fire fox. I type in, fglrxinfo ,and get a badrequest error. I have yet to type in fglrxinfo and get anything like what I am supposed to. UPDATE: I am now currently reinstalling Ubuntu 12.4. I tried the above mentioned link - thank you very much!- just to see on the previously failed driver attempt by following the purge commands. And to no avail when typing fglrxinfo I still get the badrequest thing. I will update again after a try with a true fresh install. Thanks again!! UPDATE: Alright everyone. Still no go. I have done everything word per word in the provided tutorial. I have rebooted my computer again to a fucked up resolution and this is what I get when typing fglrxinfo: $ fglrxinfo X Error of failed request: BadRequest (invalid request code or no such operation) Major opcode of failed request: 153 (GLX) Minor opcode of failed request: 19 (X_GLXQueryServerString) Serial number of failed request: 12 Current serial number in output stream: 12 I would like to add that when installing this file: fglrx_8.970-0ubuntu1_amd64.deb I got this: Building initial module for 3.8.0-29-generic Error! Bad return status for module build on kernel: 3.8.0-29-generic (x86_64) Consult /var/lib/dkms/fglrx/8.970/build/make.log for more information. update-initramfs: deferring update (trigger activated) Processing triggers for ureadahead ... Processing triggers for bamfdaemon ... Rebuilding /usr/share/applications/bamf.index... Processing triggers for initramfs-tools ... update-initramfs: Generating /boot/initrd.img-3.8.0-29-generic Processing triggers for libc-bin ... ldconfig deferred processing now taking place Any ideas? Anyone? I cant for the life of me figure out what I am doing wrong.

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  • Silverlight Binding with multiple collections

    - by George Evjen
    We're designing some sport specific applications. In one of our views we have a gridview that is bound to an observable collection of Teams. This is pretty straight forward in terms of getting Teams bound to the GridView. <telerik:RadGridView Grid.Row="0" Grid.Column="0" x:Name="UsersGrid" ItemsSource="{Binding TeamResults}" SelectedItem="{Binding SelectedTeam, Mode=TwoWay}"> <telerik:RadGridView.Columns> <telerik:GridViewDataColumn Header="Name/Group" DataMemberBinding="{Binding TeamName}" MinWidth="150"></telerik:GridViewDataColumn> </telerik:RadGridView.Columns> </telerik:RadGridView> We use the observable collection of teams as our items source and then bind the property of TeamName to the first column. You can set the binding to mode=TwoWay, we use a dialog where we edit the selected item, so our binding here is not set to two way. The issue comes when we want to bind to a property that has another collection in it. To continue on our code from above, we have an observable collection of teams, within that collection we have a collection of KeyPeople. We get this collection using RIA Serivces with the code below. return _TeamsRepository.All().Include("KeyPerson"); Here we are getting all the teams and also including the KeyPerson entity. So when we are done with our Load we will end up with an observable collection of Teams with a navigation property / entity of KeyPerson. Within this KeyPerson entity is a list of people associated with that particular team. We want to display the head coach from this list of KeyPersons. This list currently has a list of ten or more people that are bound to this team, but we just want to display the Head Coach in the column next to team name. The issue becomes how do we bind to this included entity? I have found about three different ways to solve this issue. The way that seemed to fit us best is to utilize the features within RIA Services. We can create client side properties that will do the work for us. We will create in the client side library a partial class of Team. We will end up in our library a file that is Team.shared.cs. The code below is what we will put into our partial team class. public KeyPerson Coach        {            get            {                if (this.KeyPerson != null && this.KeyPerson.Any())                { return this.KeyPerson.Where(x => x.RelationshipType == “HeadCoach”).FirstOrDefault(); }                 return null;            }        } We will return just the person that is the Head Coach and then be able to bind that and any other additional properties that we need. <telerik:GridViewDataColumn Header="Coach" DataMemberBinding="{Binding Coach.Name}" MinWidth="150"></telerik:GridViewDataColumn> There are other ways that we could have solved this issue but we felt that creating a partial class through RIA Services best suited our needs.

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  • Multidimensional multiple-choice knapsack problem: find a feasible solution

    - by Onheiron
    My assignment is to use local search heuristics to solve the Multidimensional multiple-choice knapsack problem, but to do so I first need to find a feasible solution to start with. Here is an example problem with what I tried so far. Problem R1 R2 R3 RESOUCES : 8 8 8 GROUPS: G1: 11.0 3 2 2 12.0 1 1 3 G2: 20.0 1 1 3 5.0 2 3 2 G3: 10.0 2 2 3 30.0 1 1 3 Sorting strategies To find a starting feasible solution for my local search I decided to ignore maximization of gains and just try to fit the resources requirements. I decided to sort the choices (strategies) in each group by comparing their "distance" from the multidimensional space origin, thus calculating SQRT(R1^2 + R2^2 + ... + RN^2). I felt like this was a keen solution as it somehow privileged those choices with resouce usages closer to each other (e.g. R1:2 R2:2 R3:2 < R1:1 R2:2 R3:3) even if the total sum is the same. Doing so and selecting the best choice from each group proved sufficent to find a feasible solution for many[30] different benchmark problems, but of course I knew it was just luck. So I came up with the problem presented above which sorts like this: R1 R2 R3 RESOUCES : 8 8 8 GROUPS: G1: 12.0 1 1 3 < select this 11.0 3 2 2 G2: 20.0 1 1 3 < select this 5.0 2 3 2 G3: 30.0 1 1 3 < select this 10.0 2 2 3 And it is not feasible because the resources consmption is R1:3, R2:3, R3:9. The easy solution is to pick one of the second best choices in group 1 or 2, so I'll need some kind of iteration (local search[?]) to find the starting feasible solution for my local search solution. Here are the options I came up with Option 1: iterate choices I tried to find a way to iterate all the choices with a specific order, something like G1 G2 G3 1 1 1 2 1 1 1 2 1 1 1 2 2 2 1 ... believeng that feasible solutions won't be that far away from the unfeasible one I start with and thus the number of iterations will keep quite low. Does this make any sense? If yes, how can I iterate the choices (grouped combinations) of each group keeping "as near as possibile" to the previous iteration? Option 2: Change the comparation term I tried to think how to find a better variable to sort the choices on. I thought at a measure of how "precious" a resource is based on supply and demand, so that an higer demand of a more precious resource will push you down the list, but this didn't help at all. Also I thought there probably isn't gonna be such a comparsion variable which assures me a feasible solution at first strike. I there such a variable? If not, is there a better sorting criteria anyways? Option 3: implement any known sub-optimal fast solving algorithm Unfortunately I could not find any of such algorithms online. Any suggestion?

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  • When should I use a Process Model versus a Use Case?

    - by Dave Burke
    This Blog entry is a follow on to https://blogs.oracle.com/oum/entry/oum_is_business_process_and and addresses a question I sometimes get asked…..i.e. “when I am gathering requirements on a Project, should I use a Process Modeling approach, or should I use a Use Case approach?” Not surprisingly, the short answer is “it depends”! Let’s take a scenario where you are working on a Sales Force Automation project. We’ll call the process that is being implemented “Lead-to-Order”. I would typically think of this type of project as being “Process Centric”. In other words, the focus will be on orchestrating a series of human and system related tasks that ultimately deliver value to the business in a cost effective way. Put in even simpler terms……implement an automated pre-sales system. For this type of (Process Centric) project, requirements would typically be gathered through a series of Workshops where the focal point will be on creating, or confirming, the Future-State (To-Be) business process. If pre-defined “best-practice” business process models exist, then of course they could and should be used during the Workshops, but even in their absence, the focus of the Workshops will be to define the optimum series of Tasks, their connections, sequence, and dependencies that will ultimately reflect a business process that meets the needs of the business. Now let’s take another scenario. Assume you are working on a Content Management project that involves automating the creation and management of content for User Manuals, Web Sites, Social Media publications etc. Would you call this type of project “Process Centric”?.......well you could, but it might also fall into the category of complex configuration, plus some custom extensions to a standard software application (COTS). For this type of project it would certainly be worth considering using a Use Case approach in order to 1) understand the requirements, and 2) to capture the functional requirements of the custom extensions. At this point you might be asking “why couldn’t I use a Process Modeling approach for my Content Management project?” Well, of course you could, but you just need to think about which approach is the most effective. Start by analyzing the types of Tasks that will eventually be automated by the system, for example: Best Suited To? Task Name Process Model Use Case Notes Manage outbound calls Ö A series of linked human and system tasks for calling and following up with prospects Manage content revision Ö Updating the content on a website Update User Preferences Ö Updating a users display preferences Assign Lead Ö Reviewing a lead, then assigning it to a sales person Convert Lead to Quote Ö Updating the status of a lead, and then converting it to a sales order As you can see, it’s not an exact science, and either approach is viable for the Tasks listed above. However, where you have a series of interconnected Tasks or Activities, than when combined, deliver value to the business, then that would be a good indicator to lead with a Process Modeling approach. On the other hand, when the Tasks or Activities in question are more isolated and/or do not cross traditional departmental boundaries, then a Use Case approach might be worth considering. Now let’s take one final scenario….. As you captured the To-Be Process flows for the Sales Force automation project, you discover a “Gap” in terms of what the client requires, and what the standard COTS application can provide. Let’s assume that the only way forward is to develop a Custom Extension. This would now be a perfect opportunity to document the functional requirements (behind the Gap) using a Use Case approach. After all, we will be developing some new software, and one of the most effective ways to begin the Software Development Lifecycle is to follow a Use Case approach. As always, your comments are most welcome.

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  • How to introduce a computer illiterate 50-year old to programming [closed]

    - by sunday
    The other day my dad asked me a question that I would have never expected from him. "How can I learn C++?" My dad is turning 56 this year and computers are a distant concept for him. He doesn't know how to use a phone very well besides calling numbers (no speed dial or contacts); though he has started to learn computers a little better - to the point that he knows how to open the internet (in Windows) and browse around (and has successfully completed several job applications entirely on his own online, of which he was offered positions too). But still, these are too narrow-windowed experiences to mean much, really. While he may not have the background, my dad knows how to read. And I mean reading as a skill, not just an ability. He has little to no college education (financial problems, family, etc.) and was fortunate enough to finish high school, but still taught himself to become a master electrician and has been one for almost 30 years now. He did the same with guitar, learning to play at a very professional level and has been praised for his skill. In high school, he picked up a weight lifting book - and was the only person in his high school at the time to qualify officially as an "athlete" by national standards. In all cases, he just needed something to read. Something to teach him. He absorbs information like a sponge. I have no doubt in my dad's motivation or capability of doing this, so my general goal is simply: Get my dad into the world of computers, and get him on the road to programming. I strongly believe that once I get him through the fundamentals, his drive and reading skill will keep him going on this own. So I'm asking you all: where should I start with all this? And what are the best resources out there? Should I get him to start Linux instead of Windows? Is C++ a bad idea? Remember, he needs to (IMO) learn computers first, and then get that first grasp (the "Hello world" experience) of programming. For money's sake and at top preference, I'd like free online resources that he can read, but by all means any good suggestions in print or paid-for-online are welcome (that I could possibly look into later to purchase). And also, I intend to start him off with C++ (no Python, Java, etc.), because I know it the best and will be able to help him along the way with code. (I have minimal knowledge right now in other languages). Edit: I'm getting a lot of persistent suggestions to use Python. The only reason I wanted to do C++ is that I KNOW it and can be THERE when my dad needs help. My VERY FIRST exposure to programming ever was Java. I learned Java, and I got good at it. I open to other suggestions, but please provide an effective application of your suggestions. EDIT #2: I understand my approach/thinking/knowledge could be lacking here. I'm a sophomore level undergraduate CS major. If you don't agree with anything in my post, tell me why - give me ideas, information - that's why I'm asking in the first place. To narrow down my general goal to specific reachable goals.

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  • Appropriate design / technologies to handle dynamic string formatting?

    - by Mark W
    recently I was tasked with implementing a way of adding support for versioning of hardware packet specifications to one of our libraries. First a bit of information about the project. We have a hardware library which has classes for each of the various commands we support sending to our hardware. These hardware modules are essentially just lights with a few buttons, and a 2 or 4 digit display. The packets typically follow the format {SOH}AADD{ETX}, where AA is our sentinel action code, and DD is the device ID. These packet specs are different from one command to the next obviously, and the different firmware versions we have support different specifications. For example, on version 1 an action code of 14 may have a spec of {SOH}AADDTEXT{ETX} which would be AA = 14 literal, DD = device ID, TEXT = literal text to display on the device. Then we come out with a revision with adds an extended byte(s) onto the end of the packet like this {SOH}AADDTEXTE{ETX}. Assume the TEXT field is fixed width for this example. We have now added a new field onto the end which could be used to say specify the color or flash rate of the text/buttons. Currently this java library only supports one version of the commands, the latest. In our hardware library we would have a class for this command, say a DisplayTextArgs.java. That class would have fields for the device ID, the text, and the extended byte. The command class would expose a method which generates the string ("{SOH}AADDTEXTE{ETX}") using the value from the class. In practice we would create the Args class as needed, populate the fields, call the method to get our packet string, then ship that down across the CAN. Some of our other commands specification can vary for the same command, on the same version, depending on some runtime state. For example, another command for version 1 may be {SOH}AA{ETX}, where this action code clears all of the modules behind a specific controller device of their text. We may overload this packet to have option fields with multiple meanings like {SOH}AAOC{ETX} where OC is literal text, which tells the controller to only clear text on a specific module type, and to leave the others alone, or the spec could also have an option format of {SOH}AADD{ETX} to clear the text off a a specific device. Currently, in the method which generates the packet string, we would evaluate fields on the args class to determine which spec we will be using when formatting the packet. For this example, it would be along the lines of: if m_DeviceID != null then use {SOH}AADD{ETX} else if m_ClearOCs == true then use {SOH}AAOC{EXT} else use {SOH}AA{ETX} I had considered using XML, or a database to store String.format format strings, which were linked to firmware version numbers in some table. We would load them up at startup, and pass in the version number of the hardwares firmware we are currently using (I can query the devices for their firmware version, but the version is not included in all packets as part of the spec). This breaks down pretty quickly because of the dynamic nature of how we select which version of the command to use. I then considered using a rule engine to possibly build out expressions which could be interpreted at runtume, to evaluate the args class's state, and from that select the appropriate format string to use, but my brief look at rule engines for java scared me away with its complexity. While it seems like it might be a viable solution, it seems overly complex. So this is why I am here. I wouldn't say design is my strongest skill, and im having trouble figuring out the best way to approach this problem. I probably wont be able to radically change the args classes, but if the trade off was good enough, I may be able to convince my boss that the change is appropriate. What I would like from the community is some feedback on some best practices / design methodologies / API or other resources which I could use to accomplish: Logic to determine which set of commands to use for a given firmware version Of those command, which version of each command to use (based on the args classes state) Keep the rules logic decoupled from the application so as to avoid needing releases for every firmware version Be simple enough so I don't need weeks of study and trial and error to implement effectively.

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  • SEO/Google: How should I handle multiple countries and domains?

    - by Valorized
    Hello. I'm the webmaster of an online shop based in Austria (Europe). Therefore we registered "example.at". We also own different other domain names like "example-shop.com" and "example.info". Currently all those domains are redirected (301) to the .at one. Still available is: "example.net" and "example.org" (and .ws/.cc), unfortunately not available: .de/.eu The .com is currently owned by one of our partners, the contract ends in 2012 but until then we have no chance to get this one. Recently I read more about geo-targeting and I noticed ONE big deal. The tld ".at" is hardly recognised in Germany (google.de) whereas it is excellently listed in Austria (google.at). As a result of the .at I cannot set the target location manually (or to unlisted). More info: https://www.google.com/support/webmasters/bin/answer.py?answer=62399&hl=en This is a big problem. I looked at Google Analytics and - although Germany is 10x as big as Austria - there are more visits from Austria. So, how should I config the domain in order to get the best results in both, Germany and Austria? I thought of some solutions: First I could stop redirecting the .info. Then there would be a duplicate of the .at one. Moreover, in Webmastertools, I could set the target location of the .info to Germany. As the .at still targets Austria, both would be targeted - however I don't now if google punishes one of them because of the duplicate content? Same as 1. but with .net or .org (I think .info is not a "nice" domain and moreover I think search engines prefer .com, .net or .org to .info). Same as 1. (or 2.) but with a rel="canonical" on the new one (pointing to the .at). Con: I don't think this will improve the situation, because it still tells google that the .at one is more important, like: "if .info points to .at, the target may still be Austria". rel="canonical" on the .at pointing to the new (.info or .net or .org). However I fear that this will have a negative impact on the listing on google.at because: "Hey, the well-known .at is not important anymore, so let's focus on the .info which is not well-known." - Therefore: bad position in search results. Redirect .at to the new (.info or .net or .org) with a 301-Redirect. Con: Might be worse than 4, we might loose Page-Rank (or "the value of the page", because google says that page rank is not important anymore). Moreover this might be even more confusing for the customers. In 3. or 4. customers don't get redirected, they do not see the canonical-meta-tag. So, dear experts, please tell me what the best option would be! Thank you very much for your advice in advance and please excuse the long question. I really appreciate this network! Please note: It's exactly the same content AND language. In Austria we speak German.

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  • Javascript Inheritance Part 2

    - by PhubarBaz
    A while back I wrote about Javascript inheritance, trying to figure out the best and easiest way to do it (http://geekswithblogs.net/PhubarBaz/archive/2010/07/08/javascript-inheritance.aspx). That was 2 years ago and I've learned a lot since then. But only recently have I decided to just leave classical inheritance behind and embrace prototypal inheritance. For most of us, we were trained in classical inheritance, using class hierarchies in a typed language. Unfortunately Javascript doesn't follow that model. It is both classless and typeless, which is hard to fathom for someone who's been using classes the last 20 years. For the last two or three years since I've got into Javascript I've been trying to find the best way to force it into the class model without much success. It's clunky and verbose and hard to understand. I think my biggest problem was that it felt so wrong to add or change object members at run time. Every time I did it I felt like I needed a shower. That's the 20 years of classical inheritance in me. Finally I decided to embrace change and do something different. I decided to use the factory pattern to build objects instead of trying to use inheritance. Javascript was made for the factory pattern because of the way you can construct objects at runtime. In the factory pattern you have a factory function that you call and tell it to give you a certain type of object back. The factory function takes care of constructing the object to your specification. Here's an example. Say we want to have some shape objects and they have common attributes like id and area that we want to depend on in other parts of your application. So first thing to do is create a factory object and give it a factory method to create an abstract shape object. The factory method builds the object then returns it. var shapeFactory = { getShape: function(id){ var shape = { id: id, area: function() { throw "Not implemented"; } }; return shape; }}; Now we can add another factory method to get a rectangle. It calls the getShape() method first and then adds an implementation to it. getRectangle: function(id, width, height){ var rect = this.getShape(id); rect.width = width; rect.height = height; rect.area = function() { return this.width * this.height; }; return rect;} That's pretty simple right? No worrying about hooking up prototypes and calling base constructors or any of that crap I used to do. Now let's create a factory method to get a cuboid (rectangular cube). The cuboid object will extend the rectangle object. To get the area we will call into the base object's area method and then multiply that by the depth. getCuboid: function(id, width, height, depth){ var cuboid = this.getRectangle(id, width, height); cuboid.depth = depth; var baseArea = cuboid.area; cuboid.area = function() { var a = baseArea.call(this); return a * this.depth; } return cuboid;} See how we called the area method in the base object? First we save it off in a variable then we implement our own area method and use call() to call the base function. For me this is a lot cleaner and easier than trying to emulate class hierarchies in Javascript.

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  • Agile Development

    - by James Oloo Onyango
    Alot of literature has and is being written about agile developement and its surrounding philosophies. In my quest to find the best way to express the importance of agile methodologies, i have found Robert C. Martin's "A Satire Of Two Companies" to be both the most concise and thorough! Enjoy the read! Rufus Inc Project Kick Off Your name is Bob. The date is January 3, 2001, and your head still aches from the recent millennial revelry. You are sitting in a conference room with several managers and a group of your peers. You are a project team leader. Your boss is there, and he has brought along all of his team leaders. His boss called the meeting. "We have a new project to develop," says your boss's boss. Call him BB. The points in his hair are so long that they scrape the ceiling. Your boss's points are just starting to grow, but he eagerly awaits the day when he can leave Brylcream stains on the acoustic tiles. BB describes the essence of the new market they have identified and the product they want to develop to exploit this market. "We must have this new project up and working by fourth quarter October 1," BB demands. "Nothing is of higher priority, so we are cancelling your current project." The reaction in the room is stunned silence. Months of work are simply going to be thrown away. Slowly, a murmur of objection begins to circulate around the conference table.   His points give off an evil green glow as BB meets the eyes of everyone in the room. One by one, that insidious stare reduces each attendee to quivering lumps of protoplasm. It is clear that he will brook no discussion on this matter. Once silence has been restored, BB says, "We need to begin immediately. How long will it take you to do the analysis?" You raise your hand. Your boss tries to stop you, but his spitwad misses you and you are unaware of his efforts.   "Sir, we can't tell you how long the analysis will take until we have some requirements." "The requirements document won't be ready for 3 or 4 weeks," BB says, his points vibrating with frustration. "So, pretend that you have the requirements in front of you now. How long will you require for analysis?" No one breathes. Everyone looks around to see whether anyone has some idea. "If analysis goes beyond April 1, we have a problem. Can you finish the analysis by then?" Your boss visibly gathers his courage: "We'll find a way, sir!" His points grow 3 mm, and your headache increases by two Tylenol. "Good." BB smiles. "Now, how long will it take to do the design?" "Sir," you say. Your boss visibly pales. He is clearly worried that his 3 mms are at risk. "Without an analysis, it will not be possible to tell you how long design will take." BB's expression shifts beyond austere.   "PRETEND you have the analysis already!" he says, while fixing you with his vacant, beady little eyes. "How long will it take you to do the design?" Two Tylenol are not going to cut it. Your boss, in a desperate attempt to save his new growth, babbles: "Well, sir, with only six months left to complete the project, design had better take no longer than 3 months."   "I'm glad you agree, Smithers!" BB says, beaming. Your boss relaxes. He knows his points are secure. After a while, he starts lightly humming the Brylcream jingle. BB continues, "So, analysis will be complete by April 1, design will be complete by July 1, and that gives you 3 months to implement the project. This meeting is an example of how well our new consensus and empowerment policies are working. Now, get out there and start working. I'll expect to see TQM plans and QIT assignments on my desk by next week. Oh, and don't forget that your crossfunctional team meetings and reports will be needed for next month's quality audit." "Forget the Tylenol," you think to yourself as you return to your cubicle. "I need bourbon."   Visibly excited, your boss comes over to you and says, "Gosh, what a great meeting. I think we're really going to do some world shaking with this project." You nod in agreement, too disgusted to do anything else. "Oh," your boss continues, "I almost forgot." He hands you a 30-page document. "Remember that the SEI is coming to do an evaluation next week. This is the evaluation guide. You need to read through it, memorize it, and then shred it. It tells you how to answer any questions that the SEI auditors ask you. It also tells you what parts of the building you are allowed to take them to and what parts to avoid. We are determined to be a CMM level 3 organization by June!"   You and your peers start working on the analysis of the new project. This is difficult because you have no requirements. But from the 10-minute introduction given by BB on that fateful morning, you have some idea of what the product is supposed to do.   Corporate process demands that you begin by creating a use case document. You and your team begin enumerating use cases and drawing oval and stick diagrams. Philosophical debates break out among the team members. There is disagreement as to whether certain use cases should be connected with <<extends>> or <<includes>> relationships. Competing models are created, but nobody knows how to evaluate them. The debate continues, effectively paralyzing progress.   After a week, somebody finds the iceberg.com Web site, which recommends disposing entirely of <<extends>> and <<includes>> and replacing them with <<precedes>> and <<uses>>. The documents on this Web site, authored by Don Sengroiux, describes a method known as stalwart-analysis, which claims to be a step-by-step method for translating use cases into design diagrams. More competing use case models are created using this new scheme, but again, people can't agree on how to evaluate them. The thrashing continues. More and more, the use case meetings are driven by emotion rather than by reason. If it weren't for the fact that you don't have requirements, you'd be pretty upset by the lack of progress you are making. The requirements document arrives on February 15. And then again on February 20, 25, and every week thereafter. Each new version contradicts the previous one. Clearly, the marketing folks who are writing the requirements, empowered though they might be, are not finding consensus.   At the same time, several new competing use case templates have been proposed by the various team members. Each template presents its own particularly creative way of delaying progress. The debates rage on. On March 1, Prudence Putrigence, the process proctor, succeeds in integrating all the competing use case forms and templates into a single, all-encompassing form. Just the blank form is 15 pages long. She has managed to include every field that appeared on all the competing templates. She also presents a 159- page document describing how to fill out the use case form. All current use cases must be rewritten according to the new standard.   You marvel to yourself that it now requires 15 pages of fill-in-the-blank and essay questions to answer the question: What should the system do when the user presses Return? The corporate process (authored by L. E. Ott, famed author of "Holistic Analysis: A Progressive Dialectic for Software Engineers") insists that you discover all primary use cases, 87 percent of all secondary use cases, and 36.274 percent of all tertiary use cases before you can complete analysis and enter the design phase. You have no idea what a tertiary use case is. So in an attempt to meet this requirement, you try to get your use case document reviewed by the marketing department, which you hope will know what a tertiary use case is.   Unfortunately, the marketing folks are too busy with sales support to talk to you. Indeed, since the project started, you have not been able to get a single meeting with marketing, which has provided a never-ending stream of changing and contradictory requirements documents.   While one team has been spinning endlessly on the use case document, another team has been working out the domain model. Endless variations of UML documents are pouring out of this team. Every week, the model is reworked.   The team members can't decide whether to use <<interfaces>> or <<types>> in the model. A huge disagreement has been raging on the proper syntax and application of OCL. Others on the team just got back from a 5-day class on catabolism, and have been producing incredibly detailed and arcane diagrams that nobody else can fathom.   On March 27, with one week to go before analysis is to be complete, you have produced a sea of documents and diagrams but are no closer to a cogent analysis of the problem than you were on January 3. **** And then, a miracle happens.   **** On Saturday, April 1, you check your e-mail from home. You see a memo from your boss to BB. It states unequivocally that you are done with the analysis! You phone your boss and complain. "How could you have told BB that we were done with the analysis?" "Have you looked at a calendar lately?" he responds. "It's April 1!" The irony of that date does not escape you. "But we have so much more to think about. So much more to analyze! We haven't even decided whether to use <<extends>> or <<precedes>>!" "Where is your evidence that you are not done?" inquires your boss, impatiently. "Whaaa . . . ." But he cuts you off. "Analysis can go on forever; it has to be stopped at some point. And since this is the date it was scheduled to stop, it has been stopped. Now, on Monday, I want you to gather up all existing analysis materials and put them into a public folder. Release that folder to Prudence so that she can log it in the CM system by Monday afternoon. Then get busy and start designing."   As you hang up the phone, you begin to consider the benefits of keeping a bottle of bourbon in your bottom desk drawer. They threw a party to celebrate the on-time completion of the analysis phase. BB gave a colon-stirring speech on empowerment. And your boss, another 3 mm taller, congratulated his team on the incredible show of unity and teamwork. Finally, the CIO takes the stage to tell everyone that the SEI audit went very well and to thank everyone for studying and shredding the evaluation guides that were passed out. Level 3 now seems assured and will be awarded by June. (Scuttlebutt has it that managers at the level of BB and above are to receive significant bonuses once the SEI awards level 3.)   As the weeks flow by, you and your team work on the design of the system. Of course, you find that the analysis that the design is supposedly based on is flawedno, useless; no, worse than useless. But when you tell your boss that you need to go back and work some more on the analysis to shore up its weaker sections, he simply states, "The analysis phase is over. The only allowable activity is design. Now get back to it."   So, you and your team hack the design as best you can, unsure of whether the requirements have been properly analyzed. Of course, it really doesn't matter much, since the requirements document is still thrashing with weekly revisions, and the marketing department still refuses to meet with you.     The design is a nightmare. Your boss recently misread a book named The Finish Line in which the author, Mark DeThomaso, blithely suggested that design documents should be taken down to code-level detail. "If we are going to be working at that level of detail," you ask, "why don't we simply write the code instead?" "Because then you wouldn't be designing, of course. And the only allowable activity in the design phase is design!" "Besides," he continues, "we have just purchased a companywide license for Dandelion! This tool enables 'Round the Horn Engineering!' You are to transfer all design diagrams into this tool. It will automatically generate our code for us! It will also keep the design diagrams in sync with the code!" Your boss hands you a brightly colored shrinkwrapped box containing the Dandelion distribution. You accept it numbly and shuffle off to your cubicle. Twelve hours, eight crashes, one disk reformatting, and eight shots of 151 later, you finally have the tool installed on your server. You consider the week your team will lose while attending Dandelion training. Then you smile and think, "Any week I'm not here is a good week." Design diagram after design diagram is created by your team. Dandelion makes it very difficult to draw these diagrams. There are dozens and dozens of deeply nested dialog boxes with funny text fields and check boxes that must all be filled in correctly. And then there's the problem of moving classes between packages. At first, these diagram are driven from the use cases. But the requirements are changing so often that the use cases rapidly become meaningless. Debates rage about whether VISITOR or DECORATOR design patterns should be used. One developer refuses to use VISITOR in any form, claiming that it's not a properly object-oriented construct. Someone refuses to use multiple inheritance, since it is the spawn of the devil. Review meetings rapidly degenerate into debates about the meaning of object orientation, the definition of analysis versus design, or when to use aggregation versus association. Midway through the design cycle, the marketing folks announce that they have rethought the focus of the system. Their new requirements document is completely restructured. They have eliminated several major feature areas and replaced them with feature areas that they anticipate customer surveys will show to be more appropriate. You tell your boss that these changes mean that you need to reanalyze and redesign much of the system. But he says, "The analysis phase is system. But he says, "The analysis phase is over. The only allowable activity is design. Now get back to it."   You suggest that it might be better to create a simple prototype to show to the marketing folks and even some potential customers. But your boss says, "The analysis phase is over. The only allowable activity is design. Now get back to it." Hack, hack, hack, hack. You try to create some kind of a design document that might reflect the new requirements documents. However, the revolution of the requirements has not caused them to stop thrashing. Indeed, if anything, the wild oscillations of the requirements document have only increased in frequency and amplitude.   You slog your way through them.   On June 15, the Dandelion database gets corrupted. Apparently, the corruption has been progressive. Small errors in the DB accumulated over the months into bigger and bigger errors. Eventually, the CASE tool just stopped working. Of course, the slowly encroaching corruption is present on all the backups. Calls to the Dandelion technical support line go unanswered for several days. Finally, you receive a brief e-mail from Dandelion, informing you that this is a known problem and that the solution is to purchase the new version, which they promise will be ready some time next quarter, and then reenter all the diagrams by hand.   ****   Then, on July 1 another miracle happens! You are done with the design!   Rather than go to your boss and complain, you stock your middle desk drawer with some vodka.   **** They threw a party to celebrate the on-time completion of the design phase and their graduation to CMM level 3. This time, you find BB's speech so stirring that you have to use the restroom before it begins. New banners and plaques are all over your workplace. They show pictures of eagles and mountain climbers, and they talk about teamwork and empowerment. They read better after a few scotches. That reminds you that you need to clear out your file cabinet to make room for the brandy. You and your team begin to code. But you rapidly discover that the design is lacking in some significant areas. Actually, it's lacking any significance at all. You convene a design session in one of the conference rooms to try to work through some of the nastier problems. But your boss catches you at it and disbands the meeting, saying, "The design phase is over. The only allowable activity is coding. Now get back to it."   ****   The code generated by Dandelion is really hideous. It turns out that you and your team were using association and aggregation the wrong way, after all. All the generated code has to be edited to correct these flaws. Editing this code is extremely difficult because it has been instrumented with ugly comment blocks that have special syntax that Dandelion needs in order to keep the diagrams in sync with the code. If you accidentally alter one of these comments, the diagrams will be regenerated incorrectly. It turns out that "Round the Horn Engineering" requires an awful lot of effort. The more you try to keep the code compatible with Dandelion, the more errors Dandelion generates. In the end, you give up and decide to keep the diagrams up to date manually. A second later, you decide that there's no point in keeping the diagrams up to date at all. Besides, who has time?   Your boss hires a consultant to build tools to count the number of lines of code that are being produced. He puts a big thermometer graph on the wall with the number 1,000,000 on the top. Every day, he extends the red line to show how many lines have been added. Three days after the thermometer appears on the wall, your boss stops you in the hall. "That graph isn't growing quickly enough. We need to have a million lines done by October 1." "We aren't even sh-sh-sure that the proshect will require a m-million linezh," you blather. "We have to have a million lines done by October 1," your boss reiterates. His points have grown again, and the Grecian formula he uses on them creates an aura of authority and competence. "Are you sure your comment blocks are big enough?" Then, in a flash of managerial insight, he says, "I have it! I want you to institute a new policy among the engineers. No line of code is to be longer than 20 characters. Any such line must be split into two or more preferably more. All existing code needs to be reworked to this standard. That'll get our line count up!"   You decide not to tell him that this will require two unscheduled work months. You decide not to tell him anything at all. You decide that intravenous injections of pure ethanol are the only solution. You make the appropriate arrangements. Hack, hack, hack, and hack. You and your team madly code away. By August 1, your boss, frowning at the thermometer on the wall, institutes a mandatory 50-hour workweek.   Hack, hack, hack, and hack. By September 1st, the thermometer is at 1.2 million lines and your boss asks you to write a report describing why you exceeded the coding budget by 20 percent. He institutes mandatory Saturdays and demands that the project be brought back down to a million lines. You start a campaign of remerging lines. Hack, hack, hack, and hack. Tempers are flaring; people are quitting; QA is raining trouble reports down on you. Customers are demanding installation and user manuals; salespeople are demanding advance demonstrations for special customers; the requirements document is still thrashing, the marketing folks are complaining that the product isn't anything like they specified, and the liquor store won't accept your credit card anymore. Something has to give.    On September 15, BB calls a meeting. As he enters the room, his points are emitting clouds of steam. When he speaks, the bass overtones of his carefully manicured voice cause the pit of your stomach to roll over. "The QA manager has told me that this project has less than 50 percent of the required features implemented. He has also informed me that the system crashes all the time, yields wrong results, and is hideously slow. He has also complained that he cannot keep up with the continuous train of daily releases, each more buggy than the last!" He stops for a few seconds, visibly trying to compose himself. "The QA manager estimates that, at this rate of development, we won't be able to ship the product until December!" Actually, you think it's more like March, but you don't say anything. "December!" BB roars with such derision that people duck their heads as though he were pointing an assault rifle at them. "December is absolutely out of the question. Team leaders, I want new estimates on my desk in the morning. I am hereby mandating 65-hour work weeks until this project is complete. And it better be complete by November 1."   As he leaves the conference room, he is heard to mutter: "Empowermentbah!" * * * Your boss is bald; his points are mounted on BB's wall. The fluorescent lights reflecting off his pate momentarily dazzle you. "Do you have anything to drink?" he asks. Having just finished your last bottle of Boone's Farm, you pull a bottle of Thunderbird from your bookshelf and pour it into his coffee mug. "What's it going to take to get this project done? " he asks. "We need to freeze the requirements, analyze them, design them, and then implement them," you say callously. "By November 1?" your boss exclaims incredulously. "No way! Just get back to coding the damned thing." He storms out, scratching his vacant head.   A few days later, you find that your boss has been transferred to the corporate research division. Turnover has skyrocketed. Customers, informed at the last minute that their orders cannot be fulfilled on time, have begun to cancel their orders. Marketing is re-evaluating whether this product aligns with the overall goals of the company. Memos fly, heads roll, policies change, and things are, overall, pretty grim. Finally, by March, after far too many sixty-five hour weeks, a very shaky version of the software is ready. In the field, bug-discovery rates are high, and the technical support staff are at their wits' end, trying to cope with the complaints and demands of the irate customers. Nobody is happy.   In April, BB decides to buy his way out of the problem by licensing a product produced by Rupert Industries and redistributing it. The customers are mollified, the marketing folks are smug, and you are laid off.     Rupert Industries: Project Alpha   Your name is Robert. The date is January 3, 2001. The quiet hours spent with your family this holiday have left you refreshed and ready for work. You are sitting in a conference room with your team of professionals. The manager of the division called the meeting. "We have some ideas for a new project," says the division manager. Call him Russ. He is a high-strung British chap with more energy than a fusion reactor. He is ambitious and driven but understands the value of a team. Russ describes the essence of the new market opportunity the company has identified and introduces you to Jane, the marketing manager, who is responsible for defining the products that will address it. Addressing you, Jane says, "We'd like to start defining our first product offering as soon as possible. When can you and your team meet with me?" You reply, "We'll be done with the current iteration of our project this Friday. We can spare a few hours for you between now and then. After that, we'll take a few people from the team and dedicate them to you. We'll begin hiring their replacements and the new people for your team immediately." "Great," says Russ, "but I want you to understand that it is critical that we have something to exhibit at the trade show coming up this July. If we can't be there with something significant, we'll lose the opportunity."   "I understand," you reply. "I don't yet know what it is that you have in mind, but I'm sure we can have something by July. I just can't tell you what that something will be right now. In any case, you and Jane are going to have complete control over what we developers do, so you can rest assured that by July, you'll have the most important things that can be accomplished in that time ready to exhibit."   Russ nods in satisfaction. He knows how this works. Your team has always kept him advised and allowed him to steer their development. He has the utmost confidence that your team will work on the most important things first and will produce a high-quality product.   * * *   "So, Robert," says Jane at their first meeting, "How does your team feel about being split up?" "We'll miss working with each other," you answer, "but some of us were getting pretty tired of that last project and are looking forward to a change. So, what are you people cooking up?" Jane beams. "You know how much trouble our customers currently have . . ." And she spends a half hour or so describing the problem and possible solution. "OK, wait a second" you respond. "I need to be clear about this." And so you and Jane talk about how this system might work. Some of her ideas aren't fully formed. You suggest possible solutions. She likes some of them. You continue discussing.   During the discussion, as each new topic is addressed, Jane writes user story cards. Each card represents something that the new system has to do. The cards accumulate on the table and are spread out in front of you. Both you and Jane point at them, pick them up, and make notes on them as you discuss the stories. The cards are powerful mnemonic devices that you can use to represent complex ideas that are barely formed.   At the end of the meeting, you say, "OK, I've got a general idea of what you want. I'm going to talk to the team about it. I imagine they'll want to run some experiments with various database structures and presentation formats. Next time we meet, it'll be as a group, and we'll start identifying the most important features of the system."   A week later, your nascent team meets with Jane. They spread the existing user story cards out on the table and begin to get into some of the details of the system. The meeting is very dynamic. Jane presents the stories in the order of their importance. There is much discussion about each one. The developers are concerned about keeping the stories small enough to estimate and test. So they continually ask Jane to split one story into several smaller stories. Jane is concerned that each story have a clear business value and priority, so as she splits them, she makes sure that this stays true.   The stories accumulate on the table. Jane writes them, but the developers make notes on them as needed. Nobody tries to capture everything that is said; the cards are not meant to capture everything but are simply reminders of the conversation.   As the developers become more comfortable with the stories, they begin writing estimates on them. These estimates are crude and budgetary, but they give Jane an idea of what the story will cost.   At the end of the meeting, it is clear that many more stories could be discussed. It is also clear that the most important stories have been addressed and that they represent several months worth of work. Jane closes the meeting by taking the cards with her and promising to have a proposal for the first release in the morning.   * * *   The next morning, you reconvene the meeting. Jane chooses five cards and places them on the table. "According to your estimates, these cards represent about one perfect team-week's worth of work. The last iteration of the previous project managed to get one perfect team-week done in 3 real weeks. If we can get these five stories done in 3 weeks, we'll be able to demonstrate them to Russ. That will make him feel very comfortable about our progress." Jane is pushing it. The sheepish look on her face lets you know that she knows it too. You reply, "Jane, this is a new team, working on a new project. It's a bit presumptuous to expect that our velocity will be the same as the previous team's. However, I met with the team yesterday afternoon, and we all agreed that our initial velocity should, in fact, be set to one perfectweek for every 3 real-weeks. So you've lucked out on this one." "Just remember," you continue, "that the story estimates and the story velocity are very tentative at this point. We'll learn more when we plan the iteration and even more when we implement it."   Jane looks over her glasses at you as if to say "Who's the boss around here, anyway?" and then smiles and says, "Yeah, don't worry. I know the drill by now."Jane then puts 15 more cards on the table. She says, "If we can get all these cards done by the end of March, we can turn the system over to our beta test customers. And we'll get good feedback from them."   You reply, "OK, so we've got our first iteration defined, and we have the stories for the next three iterations after that. These four iterations will make our first release."   "So," says Jane, can you really do these five stories in the next 3 weeks?" "I don't know for sure, Jane," you reply. "Let's break them down into tasks and see what we get."   So Jane, you, and your team spend the next several hours taking each of the five stories that Jane chose for the first iteration and breaking them down into small tasks. The developers quickly realize that some of the tasks can be shared between stories and that other tasks have commonalities that can probably be taken advantage of. It is clear that potential designs are popping into the developers' heads. From time to time, they form little discussion knots and scribble UML diagrams on some cards.   Soon, the whiteboard is filled with the tasks that, once completed, will implement the five stories for this iteration. You start the sign-up process by saying, "OK, let's sign up for these tasks." "I'll take the initial database generation." Says Pete. "That's what I did on the last project, and this doesn't look very different. I estimate it at two of my perfect workdays." "OK, well, then, I'll take the login screen," says Joe. "Aw, darn," says Elaine, the junior member of the team, "I've never done a GUI, and kinda wanted to try that one."   "Ah, the impatience of youth," Joe says sagely, with a wink in your direction. "You can assist me with it, young Jedi." To Jane: "I think it'll take me about three of my perfect workdays."   One by one, the developers sign up for tasks and estimate them in terms of their own perfect workdays. Both you and Jane know that it is best to let the developers volunteer for tasks than to assign the tasks to them. You also know full well that you daren't challenge any of the developers' estimates. You know these people, and you trust them. You know that they are going to do the very best they can.   The developers know that they can't sign up for more perfect workdays than they finished in the last iteration they worked on. Once each developer has filled his or her schedule for the iteration, they stop signing up for tasks.   Eventually, all the developers have stopped signing up for tasks. But, of course, tasks are still left on the board.   "I was worried that that might happen," you say, "OK, there's only one thing to do, Jane. We've got too much to do in this iteration. What stories or tasks can we remove?" Jane sighs. She knows that this is the only option. Working overtime at the beginning of a project is insane, and projects where she's tried it have not fared well.   So Jane starts to remove the least-important functionality. "Well, we really don't need the login screen just yet. We can simply start the system in the logged-in state." "Rats!" cries Elaine. "I really wanted to do that." "Patience, grasshopper." says Joe. "Those who wait for the bees to leave the hive will not have lips too swollen to relish the honey." Elaine looks confused. Everyone looks confused. "So . . .," Jane continues, "I think we can also do away with . . ." And so, bit by bit, the list of tasks shrinks. Developers who lose a task sign up for one of the remaining ones.   The negotiation is not painless. Several times, Jane exhibits obvious frustration and impatience. Once, when tensions are especially high, Elaine volunteers, "I'll work extra hard to make up some of the missing time." You are about to correct her when, fortunately, Joe looks her in the eye and says, "When once you proceed down the dark path, forever will it dominate your destiny."   In the end, an iteration acceptable to Jane is reached. It's not what Jane wanted. Indeed, it is significantly less. But it's something the team feels that can be achieved in the next 3 weeks.   And, after all, it still addresses the most important things that Jane wanted in the iteration. "So, Jane," you say when things had quieted down a bit, "when can we expect acceptance tests from you?" Jane sighs. This is the other side of the coin. For every story the development team implements,   Jane must supply a suite of acceptance tests that prove that it works. And the team needs these long before the end of the iteration, since they will certainly point out differences in the way Jane and the developers imagine the system's behaviour.   "I'll get you some example test scripts today," Jane promises. "I'll add to them every day after that. You'll have the entire suite by the middle of the iteration."   * * *   The iteration begins on Monday morning with a flurry of Class, Responsibilities, Collaborators sessions. By midmorning, all the developers have assembled into pairs and are rapidly coding away. "And now, my young apprentice," Joe says to Elaine, "you shall learn the mysteries of test-first design!"   "Wow, that sounds pretty rad," Elaine replies. "How do you do it?" Joe beams. It's clear that he has been anticipating this moment. "OK, what does the code do right now?" "Huh?" replied Elaine, "It doesn't do anything at all; there is no code."   "So, consider our task; can you think of something the code should do?" "Sure," Elaine said with youthful assurance, "First, it should connect to the database." "And thereupon, what must needs be required to connecteth the database?" "You sure talk weird," laughed Elaine. "I think we'd have to get the database object from some registry and call the Connect() method. "Ah, astute young wizard. Thou perceives correctly that we requireth an object within which we can cacheth the database object." "Is 'cacheth' really a word?" "It is when I say it! So, what test can we write that we know the database registry should pass?" Elaine sighs. She knows she'll just have to play along. "We should be able to create a database object and pass it to the registry in a Store() method. And then we should be able to pull it out of the registry with a Get() method and make sure it's the same object." "Oh, well said, my prepubescent sprite!" "Hay!" "So, now, let's write a test function that proves your case." "But shouldn't we write the database object and registry object first?" "Ah, you've much to learn, my young impatient one. Just write the test first." "But it won't even compile!" "Are you sure? What if it did?" "Uh . . ." "Just write the test, Elaine. Trust me." And so Joe, Elaine, and all the other developers began to code their tasks, one test case at a time. The room in which they worked was abuzz with the conversations between the pairs. The murmur was punctuated by an occasional high five when a pair managed to finish a task or a difficult test case.   As development proceeded, the developers changed partners once or twice a day. Each developer got to see what all the others were doing, and so knowledge of the code spread generally throughout the team.   Whenever a pair finished something significant whether a whole task or simply an important part of a task they integrated what they had with the rest of the system. Thus, the code base grew daily, and integration difficulties were minimized.   The developers communicated with Jane on a daily basis. They'd go to her whenever they had a question about the functionality of the system or the interpretation of an acceptance test case.   Jane, good as her word, supplied the team with a steady stream of acceptance test scripts. The team read these carefully and thereby gained a much better understanding of what Jane expected the system to do. By the beginning of the second week, there was enough functionality to demonstrate to Jane. She watched eagerly as the demonstration passed test case after test case. "This is really cool," Jane said as the demonstration finally ended. "But this doesn't seem like one-third of the tasks. Is your velocity slower than anticipated?"   You grimace. You'd been waiting for a good time to mention this to Jane but now she was forcing the issue. "Yes, unfortunately, we are going more slowly than we had expected. The new application server we are using is turning out to be a pain to configure. Also, it takes forever to reboot, and we have to reboot it whenever we make even the slightest change to its configuration."   Jane eyes you with suspicion. The stress of last Monday's negotiations had still not entirely dissipated. She says, "And what does this mean to our schedule? We can't slip it again, we just can't. Russ will have a fit! He'll haul us all into the woodshed and ream us some new ones."   You look Jane right in the eyes. There's no pleasant way to give someone news like this. So you just blurt out, "Look, if things keep going like they're going, we're not going to be done with everything by next Friday. Now it's possible that we'll figure out a way to go faster. But, frankly, I wouldn't depend on that. You should start thinking about one or two tasks that could be removed from the iteration without ruining the demonstration for Russ. Come hell or high water, we are going to give that demonstration on Friday, and I don't think you want us to choose which tasks to omit."   "Aw forchrisakes!" Jane barely manages to stifle yelling that last word as she stalks away, shaking her head. Not for the first time, you say to yourself, "Nobody ever promised me project management would be easy." You are pretty sure it won't be the last time, either.   Actually, things went a bit better than you had hoped. The team did, in fact, have to drop one task from the iteration, but Jane had chosen wisely, and the demonstration for Russ went without a hitch. Russ was not impressed with the progress, but neither was he dismayed. He simply said, "This is pretty good. But remember, we have to be able to demonstrate this system at the trade show in July, and at this rate, it doesn't look like you'll have all that much to show." Jane, whose attitude had improved dramatically with the completion of the iteration, responded to Russ by saying, "Russ, this team is working hard, and well. When July comes around, I am confident that we'll have something significant to demonstrate. It won't be everything, and some of it may be smoke and mirrors, but we'll have something."   Painful though the last iteration was, it had calibrated your velocity numbers. The next iteration went much better. Not because your team got more done than in the last iteration but simply because the team didn't have to remove any tasks or stories in the middle of the iteration.   By the start of the fourth iteration, a natural rhythm has been established. Jane, you, and the team know exactly what to expect from one another. The team is running hard, but the pace is sustainable. You are confident that the team can keep up this pace for a year or more.   The number of surprises in the schedule diminishes to near zero; however, the number of surprises in the requirements does not. Jane and Russ frequently look over the growing system and make recommendations or changes to the existing functionality. But all parties realize that these changes take time and must be scheduled. So the changes do not cause anyone's expectations to be violated. In March, there is a major demonstration of the system to the board of directors. The system is very limited and is not yet in a form good enough to take to the trade show, but progress is steady, and the board is reasonably impressed.   The second release goes even more smoothly than the first. By now, the team has figured out a way to automate Jane's acceptance test scripts. The team has also refactored the design of the system to the point that it is really easy to add new features and change old ones. The second release was done by the end of June and was taken to the trade show. It had less in it than Jane and Russ would have liked, but it did demonstrate the most important features of the system. Although customers at the trade show noticed that certain features were missing, they were very impressed overall. You, Russ, and Jane all returned from the trade show with smiles on your faces. You all felt as though this project was a winner.   Indeed, many months later, you are contacted by Rufus Inc. That company had been working on a system like this for its internal operations. Rufus has canceled the development of that system after a death-march project and is negotiating to license your technology for its environment.   Indeed, things are looking up!

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  • HTC to launch Windows 7 phone in India

    - by samsudeen
    It is a good news for the Indian smart phone users as the wait is finally over for Windows 7 mobile.The Taiwanese  mobile giant HTC is all set to release its Windows 7 based Smartphone series in India from January. HTC HD7 & HTC Mozart , the two smart phones running on Windows 7 OS started appearing on the HTC Indian website (HTC India) from last week.Though Flip kart (Indian online e-commerce website)  has started getting pre -orders for HTC HD7 a month ago , the buzz has started from last week after the introduction of “HTC Mozart”. The complete feature comparison between both the smart phones is given below. Feature Comparison HTC Mozart HTC HD 7 Microsoft Windows 7 Microsoft Windows 7 Qualcomm Snapdragon Processor QSD 8250 1 GHz CPU Qualcomm Snapdragon Processor QSD 8250 1 GHz CPU 8MegaPixel camera with Xenon Flash 5 MP, 2592?1944 pixels, autofocus, dual-LED flash, 480 x 800 pixels, 3.7 inches 480 x 800 pixels, 4.3 inches 11.9mm thick and Weighs 130g 11.2 mm thick and Weighs 162 g Bluetooth 2.1 Bluetooth 2.1 8 GB of internal storage memory 8 GB of internal storage memory 512MB of ROM and 576 of RAM 512MB of ROM and 576 of RAM 3G HSDPA 7.2 Mbps and HSUPA 2 Mbps 3G HSDPA 7.2 Mbps; HSUPA 2 Mbps Wi-Fi 802.11 b/g/n Wi-Fi 802.11 b/g/n Micro-USB interconnector Micro-USB interconnector 3.5mm audio jack 3.5mm audio jack GPS antenna GPS antenna Standard battery Li-Po 1300 MA Standard battery, Li-Ion 1230 MA Standby 360 h (2G) up to 435 h (3G) Up to 310 h (2G) / Up to 320 h (3G) Talk time Up to 6 h 40 min (2G) and 5 h 30 min (3G) Up to 6 h 20 min (2G) / Up to 5 h 20 min (3G) Estimated Price “HTC HD 7″ is priced between  INR 27855 to 32000. though the price of “HDT Mozart” is officially not announced it is estimated to be around INR 30000. Where to Buy The Windows 7 phone is not yet available in stores directly, but most of the leading mobile stores are getting pre -orders. I have given some of the online store links below. Flip kart UniverCell This article titled,HTC to launch Windows 7 phone in India, was originally published at Tech Dreams. Grab our rss feed or fan us on Facebook to get updates from us.

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  • Toorcon14

    - by danx
    Toorcon 2012 Information Security Conference San Diego, CA, http://www.toorcon.org/ Dan Anderson, October 2012 It's almost Halloween, and we all know what that means—yes, of course, it's time for another Toorcon Conference! Toorcon is an annual conference for people interested in computer security. This includes the whole range of hackers, computer hobbyists, professionals, security consultants, press, law enforcement, prosecutors, FBI, etc. We're at Toorcon 14—see earlier blogs for some of the previous Toorcon's I've attended (back to 2003). This year's "con" was held at the Westin on Broadway in downtown San Diego, California. The following are not necessarily my views—I'm just the messenger—although I could have misquoted or misparaphrased the speakers. Also, I only reviewed some of the talks, below, which I attended and interested me. MalAndroid—the Crux of Android Infections, Aditya K. Sood Programming Weird Machines with ELF Metadata, Rebecca "bx" Shapiro Privacy at the Handset: New FCC Rules?, Valkyrie Hacking Measured Boot and UEFI, Dan Griffin You Can't Buy Security: Building the Open Source InfoSec Program, Boris Sverdlik What Journalists Want: The Investigative Reporters' Perspective on Hacking, Dave Maas & Jason Leopold Accessibility and Security, Anna Shubina Stop Patching, for Stronger PCI Compliance, Adam Brand McAfee Secure & Trustmarks — a Hacker's Best Friend, Jay James & Shane MacDougall MalAndroid—the Crux of Android Infections Aditya K. Sood, IOActive, Michigan State PhD candidate Aditya talked about Android smartphone malware. There's a lot of old Android software out there—over 50% Gingerbread (2.3.x)—and most have unpatched vulnerabilities. Of 9 Android vulnerabilities, 8 have known exploits (such as the old Gingerbread Global Object Table exploit). Android protection includes sandboxing, security scanner, app permissions, and screened Android app market. The Android permission checker has fine-grain resource control, policy enforcement. Android static analysis also includes a static analysis app checker (bouncer), and a vulnerablity checker. What security problems does Android have? User-centric security, which depends on the user to grant permission and make smart decisions. But users don't care or think about malware (the're not aware, not paranoid). All they want is functionality, extensibility, mobility Android had no "proper" encryption before Android 3.0 No built-in protection against social engineering and web tricks Alternative Android app markets are unsafe. Simply visiting some markets can infect Android Aditya classified Android Malware types as: Type A—Apps. These interact with the Android app framework. For example, a fake Netflix app. Or Android Gold Dream (game), which uploads user files stealthy manner to a remote location. Type K—Kernel. Exploits underlying Linux libraries or kernel Type H—Hybrid. These use multiple layers (app framework, libraries, kernel). These are most commonly used by Android botnets, which are popular with Chinese botnet authors What are the threats from Android malware? These incude leak info (contacts), banking fraud, corporate network attacks, malware advertising, malware "Hackivism" (the promotion of social causes. For example, promiting specific leaders of the Tunisian or Iranian revolutions. Android malware is frequently "masquerated". That is, repackaged inside a legit app with malware. To avoid detection, the hidden malware is not unwrapped until runtime. The malware payload can be hidden in, for example, PNG files. Less common are Android bootkits—there's not many around. What they do is hijack the Android init framework—alteering system programs and daemons, then deletes itself. For example, the DKF Bootkit (China). Android App Problems: no code signing! all self-signed native code execution permission sandbox — all or none alternate market places no robust Android malware detection at network level delayed patch process Programming Weird Machines with ELF Metadata Rebecca "bx" Shapiro, Dartmouth College, NH https://github.com/bx/elf-bf-tools @bxsays on twitter Definitions. "ELF" is an executable file format used in linking and loading executables (on UNIX/Linux-class machines). "Weird machine" uses undocumented computation sources (I think of them as unintended virtual machines). Some examples of "weird machines" are those that: return to weird location, does SQL injection, corrupts the heap. Bx then talked about using ELF metadata as (an uintended) "weird machine". Some ELF background: A compiler takes source code and generates a ELF object file (hello.o). A static linker makes an ELF executable from the object file. A runtime linker and loader takes ELF executable and loads and relocates it in memory. The ELF file has symbols to relocate functions and variables. ELF has two relocation tables—one at link time and another one at loading time: .rela.dyn (link time) and .dynsym (dynamic table). GOT: Global Offset Table of addresses for dynamically-linked functions. PLT: Procedure Linkage Tables—works with GOT. The memory layout of a process (not the ELF file) is, in order: program (+ heap), dynamic libraries, libc, ld.so, stack (which includes the dynamic table loaded into memory) For ELF, the "weird machine" is found and exploited in the loader. ELF can be crafted for executing viruses, by tricking runtime into executing interpreted "code" in the ELF symbol table. One can inject parasitic "code" without modifying the actual ELF code portions. Think of the ELF symbol table as an "assembly language" interpreter. It has these elements: instructions: Add, move, jump if not 0 (jnz) Think of symbol table entries as "registers" symbol table value is "contents" immediate values are constants direct values are addresses (e.g., 0xdeadbeef) move instruction: is a relocation table entry add instruction: relocation table "addend" entry jnz instruction: takes multiple relocation table entries The ELF weird machine exploits the loader by relocating relocation table entries. The loader will go on forever until told to stop. It stores state on stack at "end" and uses IFUNC table entries (containing function pointer address). The ELF weird machine, called "Brainfu*k" (BF) has: 8 instructions: pointer inc, dec, inc indirect, dec indirect, jump forward, jump backward, print. Three registers - 3 registers Bx showed example BF source code that implemented a Turing machine printing "hello, world". More interesting was the next demo, where bx modified ping. Ping runs suid as root, but quickly drops privilege. BF modified the loader to disable the library function call dropping privilege, so it remained as root. Then BF modified the ping -t argument to execute the -t filename as root. It's best to show what this modified ping does with an example: $ whoami bx $ ping localhost -t backdoor.sh # executes backdoor $ whoami root $ The modified code increased from 285948 bytes to 290209 bytes. A BF tool compiles "executable" by modifying the symbol table in an existing ELF executable. The tool modifies .dynsym and .rela.dyn table, but not code or data. Privacy at the Handset: New FCC Rules? "Valkyrie" (Christie Dudley, Santa Clara Law JD candidate) Valkyrie talked about mobile handset privacy. Some background: Senator Franken (also a comedian) became alarmed about CarrierIQ, where the carriers track their customers. Franken asked the FCC to find out what obligations carriers think they have to protect privacy. The carriers' response was that they are doing just fine with self-regulation—no worries! Carriers need to collect data, such as missed calls, to maintain network quality. But carriers also sell data for marketing. Verizon sells customer data and enables this with a narrow privacy policy (only 1 month to opt out, with difficulties). The data sold is not individually identifiable and is aggregated. But Verizon recommends, as an aggregation workaround to "recollate" data to other databases to identify customers indirectly. The FCC has regulated telephone privacy since 1934 and mobile network privacy since 2007. Also, the carriers say mobile phone privacy is a FTC responsibility (not FCC). FTC is trying to improve mobile app privacy, but FTC has no authority over carrier / customer relationships. As a side note, Apple iPhones are unique as carriers have extra control over iPhones they don't have with other smartphones. As a result iPhones may be more regulated. Who are the consumer advocates? Everyone knows EFF, but EPIC (Electrnic Privacy Info Center), although more obsecure, is more relevant. What to do? Carriers must be accountable. Opt-in and opt-out at any time. Carriers need incentive to grant users control for those who want it, by holding them liable and responsible for breeches on their clock. Location information should be added current CPNI privacy protection, and require "Pen/trap" judicial order to obtain (and would still be a lower standard than 4th Amendment). Politics are on a pro-privacy swing now, with many senators and the Whitehouse. There will probably be new regulation soon, and enforcement will be a problem, but consumers will still have some benefit. Hacking Measured Boot and UEFI Dan Griffin, JWSecure, Inc., Seattle, @JWSdan Dan talked about hacking measured UEFI boot. First some terms: UEFI is a boot technology that is replacing BIOS (has whitelisting and blacklisting). UEFI protects devices against rootkits. TPM - hardware security device to store hashs and hardware-protected keys "secure boot" can control at firmware level what boot images can boot "measured boot" OS feature that tracks hashes (from BIOS, boot loader, krnel, early drivers). "remote attestation" allows remote validation and control based on policy on a remote attestation server. Microsoft pushing TPM (Windows 8 required), but Google is not. Intel TianoCore is the only open source for UEFI. Dan has Measured Boot Tool at http://mbt.codeplex.com/ with a demo where you can also view TPM data. TPM support already on enterprise-class machines. UEFI Weaknesses. UEFI toolkits are evolving rapidly, but UEFI has weaknesses: assume user is an ally trust TPM implicitly, and attached to computer hibernate file is unprotected (disk encryption protects against this) protection migrating from hardware to firmware delays in patching and whitelist updates will UEFI really be adopted by the mainstream (smartphone hardware support, bank support, apathetic consumer support) You Can't Buy Security: Building the Open Source InfoSec Program Boris Sverdlik, ISDPodcast.com co-host Boris talked about problems typical with current security audits. "IT Security" is an oxymoron—IT exists to enable buiness, uptime, utilization, reporting, but don't care about security—IT has conflict of interest. There's no Magic Bullet ("blinky box"), no one-size-fits-all solution (e.g., Intrusion Detection Systems (IDSs)). Regulations don't make you secure. The cloud is not secure (because of shared data and admin access). Defense and pen testing is not sexy. Auditors are not solution (security not a checklist)—what's needed is experience and adaptability—need soft skills. Step 1: First thing is to Google and learn the company end-to-end before you start. Get to know the management team (not IT team), meet as many people as you can. Don't use arbitrary values such as CISSP scores. Quantitive risk assessment is a myth (e.g. AV*EF-SLE). Learn different Business Units, legal/regulatory obligations, learn the business and where the money is made, verify company is protected from script kiddies (easy), learn sensitive information (IP, internal use only), and start with low-hanging fruit (customer service reps and social engineering). Step 2: Policies. Keep policies short and relevant. Generic SANS "security" boilerplate policies don't make sense and are not followed. Focus on acceptable use, data usage, communications, physical security. Step 3: Implementation: keep it simple stupid. Open source, although useful, is not free (implementation cost). Access controls with authentication & authorization for local and remote access. MS Windows has it, otherwise use OpenLDAP, OpenIAM, etc. Application security Everyone tries to reinvent the wheel—use existing static analysis tools. Review high-risk apps and major revisions. Don't run different risk level apps on same system. Assume host/client compromised and use app-level security control. Network security VLAN != segregated because there's too many workarounds. Use explicit firwall rules, active and passive network monitoring (snort is free), disallow end user access to production environment, have a proxy instead of direct Internet access. Also, SSL certificates are not good two-factor auth and SSL does not mean "safe." Operational Controls Have change, patch, asset, & vulnerability management (OSSI is free). For change management, always review code before pushing to production For logging, have centralized security logging for business-critical systems, separate security logging from administrative/IT logging, and lock down log (as it has everything). Monitor with OSSIM (open source). Use intrusion detection, but not just to fulfill a checkbox: build rules from a whitelist perspective (snort). OSSEC has 95% of what you need. Vulnerability management is a QA function when done right: OpenVas and Seccubus are free. Security awareness The reality is users will always click everything. Build real awareness, not compliance driven checkbox, and have it integrated into the culture. Pen test by crowd sourcing—test with logging COSSP http://www.cossp.org/ - Comprehensive Open Source Security Project What Journalists Want: The Investigative Reporters' Perspective on Hacking Dave Maas, San Diego CityBeat Jason Leopold, Truthout.org The difference between hackers and investigative journalists: For hackers, the motivation varies, but method is same, technological specialties. For investigative journalists, it's about one thing—The Story, and they need broad info-gathering skills. J-School in 60 Seconds: Generic formula: Person or issue of pubic interest, new info, or angle. Generic criteria: proximity, prominence, timeliness, human interest, oddity, or consequence. Media awareness of hackers and trends: journalists becoming extremely aware of hackers with congressional debates (privacy, data breaches), demand for data-mining Journalists, use of coding and web development for Journalists, and Journalists busted for hacking (Murdock). Info gathering by investigative journalists include Public records laws. Federal Freedom of Information Act (FOIA) is good, but slow. California Public Records Act is a lot stronger. FOIA takes forever because of foot-dragging—it helps to be specific. Often need to sue (especially FBI). CPRA is faster, and requests can be vague. Dumps and leaks (a la Wikileaks) Journalists want: leads, protecting ourselves, our sources, and adapting tools for news gathering (Google hacking). Anonomity is important to whistleblowers. They want no digital footprint left behind (e.g., email, web log). They don't trust encryption, want to feel safe and secure. Whistleblower laws are very weak—there's no upside for whistleblowers—they have to be very passionate to do it. Accessibility and Security or: How I Learned to Stop Worrying and Love the Halting Problem Anna Shubina, Dartmouth College Anna talked about how accessibility and security are related. Accessibility of digital content (not real world accessibility). mostly refers to blind users and screenreaders, for our purpose. Accessibility is about parsing documents, as are many security issues. "Rich" executable content causes accessibility to fail, and often causes security to fail. For example MS Word has executable format—it's not a document exchange format—more dangerous than PDF or HTML. Accessibility is often the first and maybe only sanity check with parsing. They have no choice because someone may want to read what you write. Google, for example, is very particular about web browser you use and are bad at supporting other browsers. Uses JavaScript instead of links, often requiring mouseover to display content. PDF is a security nightmare. Executible format, embedded flash, JavaScript, etc. 15 million lines of code. Google Chrome doesn't handle PDF correctly, causing several security bugs. PDF has an accessibility checker and PDF tagging, to help with accessibility. But no PDF checker checks for incorrect tags, untagged content, or validates lists or tables. None check executable content at all. The "Halting Problem" is: can one decide whether a program will ever stop? The answer, in general, is no (Rice's theorem). The same holds true for accessibility checkers. Language-theoretic Security says complicated data formats are hard to parse and cannot be solved due to the Halting Problem. W3C Web Accessibility Guidelines: "Perceivable, Operable, Understandable, Robust" Not much help though, except for "Robust", but here's some gems: * all information should be parsable (paraphrasing) * if not parsable, cannot be converted to alternate formats * maximize compatibility in new document formats Executible webpages are bad for security and accessibility. They say it's for a better web experience. But is it necessary to stuff web pages with JavaScript for a better experience? A good example is The Drudge Report—it has hand-written HTML with no JavaScript, yet drives a lot of web traffic due to good content. A bad example is Google News—hidden scrollbars, guessing user input. Solutions: Accessibility and security problems come from same source Expose "better user experience" myth Keep your corner of Internet parsable Remember "Halting Problem"—recognize false solutions (checking and verifying tools) Stop Patching, for Stronger PCI Compliance Adam Brand, protiviti @adamrbrand, http://www.picfun.com/ Adam talked about PCI compliance for retail sales. Take an example: for PCI compliance, 50% of Brian's time (a IT guy), 960 hours/year was spent patching POSs in 850 restaurants. Often applying some patches make no sense (like fixing a browser vulnerability on a server). "Scanner worship" is overuse of vulnerability scanners—it gives a warm and fuzzy and it's simple (red or green results—fix reds). Scanners give a false sense of security. In reality, breeches from missing patches are uncommon—more common problems are: default passwords, cleartext authentication, misconfiguration (firewall ports open). Patching Myths: Myth 1: install within 30 days of patch release (but PCI §6.1 allows a "risk-based approach" instead). Myth 2: vendor decides what's critical (also PCI §6.1). But §6.2 requires user ranking of vulnerabilities instead. Myth 3: scan and rescan until it passes. But PCI §11.2.1b says this applies only to high-risk vulnerabilities. Adam says good recommendations come from NIST 800-40. Instead use sane patching and focus on what's really important. From NIST 800-40: Proactive: Use a proactive vulnerability management process: use change control, configuration management, monitor file integrity. Monitor: start with NVD and other vulnerability alerts, not scanner results. Evaluate: public-facing system? workstation? internal server? (risk rank) Decide:on action and timeline Test: pre-test patches (stability, functionality, rollback) for change control Install: notify, change control, tickets McAfee Secure & Trustmarks — a Hacker's Best Friend Jay James, Shane MacDougall, Tactical Intelligence Inc., Canada "McAfee Secure Trustmark" is a website seal marketed by McAfee. A website gets this badge if they pass their remote scanning. The problem is a removal of trustmarks act as flags that you're vulnerable. Easy to view status change by viewing McAfee list on website or on Google. "Secure TrustGuard" is similar to McAfee. Jay and Shane wrote Perl scripts to gather sites from McAfee and search engines. If their certification image changes to a 1x1 pixel image, then they are longer certified. Their scripts take deltas of scans to see what changed daily. The bottom line is change in TrustGuard status is a flag for hackers to attack your site. Entire idea of seals is silly—you're raising a flag saying if you're vulnerable.

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  • Is your team is a high-performing team?

    As a child I can remember looking out of the car window as my father drove along the Interstate in Florida while seeing prisoners wearing bright orange jump suits and prison guards keeping a watchful eye on them. The prisoners were taking part in a prison road gang. These road gangs were formed to help the state maintain the state highway infrastructure. The prisoner’s primary responsibilities are to pick up trash and debris from the roadway. This is a prime example of a work group or working group used by most prison systems in the United States. Work groups or working groups can be defined as a collection of individuals or entities working together to achieve a specific goal or accomplish a specific set of tasks. Typically these groups are only established for a short period of time and are dissolved once the desired outcome has been achieved. More often than not group members usually feel as though they are expendable to the group and some even dread that they are even in the group. "A team is a small number of people with complementary skills who are committed to a common purpose, performance goals, and approach for which they are mutually accountable." (Katzenbach and Smith, 1993) So how do you determine that a team is a high-performing team?  This can be determined by three base line criteria that include: consistently high quality output, the promotion of personal growth and well being of all team members, and most importantly the ability to learn and grow as a unit. Initially, a team can successfully create high-performing output without meeting all three criteria, however this will erode over time because team members will feel detached from the group or that they are not growing then the quality of the output will decline. High performing teams are similar to work groups because they both utilize a collection of individuals or entities to accomplish tasks. What distinguish a high-performing team from a work group are its characteristics. High-performing teams contain five core characteristics. These characteristics are what separate a group from a team. The five characteristics of a high-performing team include: Purpose, Performance Measures, People with Tasks and Relationship Skills, Process, and Preparation and Practice. A high-performing team is much more than a work group, and typically has a life cycle that can vary from team to team. The standard team lifecycle consists of five states and is comparable to a human life cycle. The five states of a high-performing team lifecycle include: Formulating, Storming, Normalizing, Performing, and Adjourning. The Formulating State of a team is first realized when the team members are first defined and roles are assigned to all members. This initial stage is very important because it can set the tone for the team and can ultimately determine its success or failure. In addition, this stage requires the team to have a strong leader because team members are normally unclear about specific roles, specific obstacles and goals that my lay ahead of them.  Finally, this stage is where most team members initially meet one another prior to working as a team unless the team members already know each other. The Storming State normally arrives directly after the formulation of a new team because there are still a lot of unknowns amongst the newly formed assembly. As a general rule most of the parties involved in the team are still getting used to the workload, pace of work, deadlines and the validity of various tasks that need to be performed by the group.  In this state everything is questioned because there are so many unknowns. Items commonly questioned include the credentials of others on the team, the actual validity of a project, and the leadership abilities of the team leader.  This can be exemplified by looking at the interactions between animals when they first meet.  If we look at a scenario where two people are walking directly toward each other with their dogs. The dogs will automatically enter the Storming State because they do not know the other dog. Typically in this situation, they attempt to define which is more dominating via play or fighting depending on how the dogs interact with each other. Once dominance has been defined and accepted by both dogs then they will either want to play or leave depending on how the dogs interacted and other environmental variables. Once the Storming State has been realized then the Normalizing State takes over. This state is entered by a team once all the questions of the Storming State have been answered and the team has been tested by a few tasks or projects.  Typically, participants in the team are filled with energy, and comradery, and a strong alliance with team goals and objectives.  A high school football team is a perfect example of the Normalizing State when they start their season.  The player positions have been assigned, the depth chart has been filled and everyone is focused on winning each game. All of the players encourage and expect each other to perform at the best of their abilities and are united by competition from other teams. The Performing State is achieved by a team when its history, working habits, and culture solidify the team as one working unit. In this state team members can anticipate specific behaviors, attitudes, reactions, and challenges are seen as opportunities and not problems. Additionally, each team member knows their role in the team’s success, and the roles of others. This is the most productive state of a group and is where all the time invested working together really pays off. If you look at an Olympic figure skating team skate you can easily see how the time spent working together benefits their performance. They skate as one unit even though it is comprised of two skaters. Each skater has their routine completely memorized as well as their partners. This allows them to anticipate each other’s moves on the ice makes their skating look effortless. The final state of a team is the Adjourning State. This state is where accomplishments by the team and each individual team member are recognized. Additionally, this state also allows for reflection of the interactions between team members, work accomplished and challenges that were faced. Finally, the team celebrates the challenges they have faced and overcome as a unit. Currently in the workplace teams are divided into two different types: Co-located and Distributed Teams. Co-located teams defined as the traditional group of people working together in an office, according to Andy Singleton of Assembla. This traditional type of a team has dominated business in the past due to inadequate technology, which forced workers to primarily interact with one another via face to face meetings.  Team meetings are primarily lead by the person with the highest status in the company. Having personally, participated in meetings of this type, usually a select few of the team members dominate the flow of communication which reduces the input of others in group discussions. Since discussions are dominated by a select few individuals the discussions and group discussion are skewed in favor of the individuals who communicate the most in meetings. In addition, Team members might not give their full opinions on a topic of discussion in part not to offend or create controversy amongst the team and can alter decision made in meetings towards those of the opinions of the dominating team members. Distributed teams are by definition spread across an area or subdivided into separate sections. That is exactly what distributed teams when compared to a more traditional team. It is common place for distributed teams to have team members across town, in the next state, across the country and even with the advances in technology over the last 20 year across the world. These teams allow for more diversity compared to the other type of teams because they allow for more flexibility regarding location. A team could consist of a 30 year old male Italian project manager from New York, a 50 year old female Hispanic from California and a collection of programmers from India because technology allows them to communicate as if they were standing next to one another.  In addition, distributed team members consult with more team members prior to making decisions compared to traditional teams, and take longer to come to decisions due to the changes in time zones and cultural events. However, team members feel more empowered to speak out when they do not agree with the team and to notify others of potential issues regarding the work that the team is doing. Virtual teams which are a subset of the distributed team type is changing organizational strategies due to the fact that a team can now in essence be working 24 hrs a day because of utilizing employees in various time zones and locations.  A primary example of this is with customer services departments, a company can have multiple call centers spread across multiple time zones allowing them to appear to be open 24 hours a day while all a employees work from 9AM to 5 PM every day. Virtual teams also allow human resources departments to go after the best talent for the company regardless of where the potential employee works because they will be a part of a virtual team all that is need is the proper technology to be setup to allow everyone to communicate. In addition to allowing employees to work from home, the company can save space and resources by not having to provide a desk for every team member. In fact, those team members that randomly come into the office can actually share one desk amongst multiple people. This is definitely a cost cutting plus given the current state of the economy. One thing that can turn a team into a high-performing team is leadership. High-performing team leaders need to focus on investing in ongoing personal development, provide team members with direction, structure, and resources needed to accomplish their work, make the right interventions at the right time, and help the team manage boundaries between the team and various external parties involved in the teams work. A team leader needs to invest in ongoing personal development in order to effectively manage their team. People have said that attitude is everything; this is very true about leaders and leadership. A team takes on the attitudes and behaviors of its leaders. This can potentially harm the team and the team’s output. Leaders must concentrate on self-awareness, and understanding their team’s group dynamics to fully understand how to lead them. In addition, always learning new leadership techniques from other effective leaders is also very beneficial. Providing team members with direction, structure, and resources that they need to accomplish their work collectively sounds easy, but it is not.  Leaders need to be able to effectively communicate with their team on how their work helps the company reach for its organizational vision. Conversely, the leader needs to allow his team to work autonomously within specific guidelines to turn the company’s vision into a reality.  This being said the team must be appropriately staffed according to the size of the team’s tasks and their complexity. These tasks should be clear, and be meaningful to the company’s objectives and allow for feedback to be exchanged with the leader and the team member and the leader and upper management. Now if the team is properly staffed, and has a clear and full understanding of what is to be done; the company also must supply the workers with the proper tools to achieve the tasks that they are asked to do. No one should be asked to dig a hole without being given a shovel.  Finally, leaders must reward their team members for accomplishments that they achieve. Awards could range from just a simple congratulatory email, a party to close the completion of a large project, or other monetary rewards. Managing boundaries is very important for team leaders because it can alter attitudes of team members and can add undue stress to the team which will force them to loose focus on the tasks at hand for the group. Team leaders should promote communication between team members so that burdens are shared amongst the team and solutions can be derived from hearing the opinions of multiple sources. This also reinforces team camaraderie and working as a unit. Team leaders must manage the type and timing of interventions as to not create an even bigger mess within the team. Poorly timed interventions can really deflate team members and make them question themselves. This could really increase further and undue interventions by the team leader. Typically, the best time for interventions is when the team is just starting to form so that all unproductive behaviors are removed from the team and that it can retain focus on its agenda. If an intervention is effectively executed the team will feel energized about the work that they are doing, promote communication and interaction amongst the group and improve moral overall. High-performing teams are very import to organizations because they consistently produce high quality output and develop a collective purpose for their work. This drive to succeed allows team members to utilize specific talents allowing for growth in these areas.  In addition, these team members usually take on a sense of ownership with their projects and feel that the other team members are irreplaceable. References: http://blog.assembla.com/assemblablog/tabid/12618/bid/3127/Three-ways-to-organize-your-team-co-located-outsourced-or-global.aspx Katzenbach, J.R. & Smith, D.K. (1993). The Wisdom of Teams: Creating the High-performance Organization. Boston: Harvard Business School.

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  • More CPU cores may not always lead to better performance – MAXDOP and query memory distribution in spotlight

    - by sqlworkshops
    More hardware normally delivers better performance, but there are exceptions where it can hinder performance. Understanding these exceptions and working around it is a major part of SQL Server performance tuning.   When a memory allocating query executes in parallel, SQL Server distributes memory to each task that is executing part of the query in parallel. In our example the sort operator that executes in parallel divides the memory across all tasks assuming even distribution of rows. Common memory allocating queries are that perform Sort and do Hash Match operations like Hash Join or Hash Aggregation or Hash Union.   In reality, how often are column values evenly distributed, think about an example; are employees working for your company distributed evenly across all the Zip codes or mainly concentrated in the headquarters? What happens when you sort result set based on Zip codes? Do all products in the catalog sell equally or are few products hot selling items?   One of my customers tested the below example on a 24 core server with various MAXDOP settings and here are the results:MAXDOP 1: CPU time = 1185 ms, elapsed time = 1188 msMAXDOP 4: CPU time = 1981 ms, elapsed time = 1568 msMAXDOP 8: CPU time = 1918 ms, elapsed time = 1619 msMAXDOP 12: CPU time = 2367 ms, elapsed time = 2258 msMAXDOP 16: CPU time = 2540 ms, elapsed time = 2579 msMAXDOP 20: CPU time = 2470 ms, elapsed time = 2534 msMAXDOP 0: CPU time = 2809 ms, elapsed time = 2721 ms - all 24 cores.In the above test, when the data was evenly distributed, the elapsed time of parallel query was always lower than serial query.   Why does the query get slower and slower with more CPU cores / higher MAXDOP? Maybe you can answer this question after reading the article; let me know: [email protected].   Well you get the point, let’s see an example.   The best way to learn is to practice. To create the below tables and reproduce the behavior, join the mailing list by using this link: www.sqlworkshops.com/ml and I will send you the table creation script.   Let’s update the Employees table with 49 out of 50 employees located in Zip code 2001. update Employees set Zip = EmployeeID / 400 + 1 where EmployeeID % 50 = 1 update Employees set Zip = 2001 where EmployeeID % 50 != 1 go update statistics Employees with fullscan go   Let’s create the temporary table #FireDrill with all possible Zip codes. drop table #FireDrill go create table #FireDrill (Zip int primary key) insert into #FireDrill select distinct Zip from Employees update statistics #FireDrill with fullscan go  Let’s execute the query serially with MAXDOP 1. --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --First serially with MAXDOP 1 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 1) goThe query took 1011 ms to complete.   The execution plan shows the 77816 KB of memory was granted while the estimated rows were 799624.  No Sort Warnings in SQL Server Profiler.  Now let’s execute the query in parallel with MAXDOP 0. --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --In parallel with MAXDOP 0 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 0) go The query took 1912 ms to complete.  The execution plan shows the 79360 KB of memory was granted while the estimated rows were 799624.  The estimated number of rows between serial and parallel plan are the same. The parallel plan has slightly more memory granted due to additional overhead. Sort properties shows the rows are unevenly distributed over the 4 threads.   Sort Warnings in SQL Server Profiler.   Intermediate Summary: The reason for the higher duration with parallel plan was sort spill. This is due to uneven distribution of employees over Zip codes, especially concentration of 49 out of 50 employees in Zip code 2001. Now let’s update the Employees table and distribute employees evenly across all Zip codes.   update Employees set Zip = EmployeeID / 400 + 1 go update statistics Employees with fullscan go  Let’s execute the query serially with MAXDOP 1. --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --Serially with MAXDOP 1 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 1) go   The query took 751 ms to complete.  The execution plan shows the 77816 KB of memory was granted while the estimated rows were 784707.  No Sort Warnings in SQL Server Profiler.   Now let’s execute the query in parallel with MAXDOP 0. --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --In parallel with MAXDOP 0 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 0) go The query took 661 ms to complete.  The execution plan shows the 79360 KB of memory was granted while the estimated rows were 784707.  Sort properties shows the rows are evenly distributed over the 4 threads. No Sort Warnings in SQL Server Profiler.    Intermediate Summary: When employees were distributed unevenly, concentrated on 1 Zip code, parallel sort spilled while serial sort performed well without spilling to tempdb. When the employees were distributed evenly across all Zip codes, parallel sort and serial sort did not spill to tempdb. This shows uneven data distribution may affect the performance of some parallel queries negatively. For detailed discussion of memory allocation, refer to webcasts available at www.sqlworkshops.com/webcasts.     Some of you might conclude from the above execution times that parallel query is not faster even when there is no spill. Below you can see when we are joining limited amount of Zip codes, parallel query will be fasted since it can use Bitmap Filtering.   Let’s update the Employees table with 49 out of 50 employees located in Zip code 2001. update Employees set Zip = EmployeeID / 400 + 1 where EmployeeID % 50 = 1 update Employees set Zip = 2001 where EmployeeID % 50 != 1 go update statistics Employees with fullscan go  Let’s create the temporary table #FireDrill with limited Zip codes. drop table #FireDrill go create table #FireDrill (Zip int primary key) insert into #FireDrill select distinct Zip       from Employees where Zip between 1800 and 2001 update statistics #FireDrill with fullscan go  Let’s execute the query serially with MAXDOP 1. --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --Serially with MAXDOP 1 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 1) go The query took 989 ms to complete.  The execution plan shows the 77816 KB of memory was granted while the estimated rows were 785594. No Sort Warnings in SQL Server Profiler.  Now let’s execute the query in parallel with MAXDOP 0. --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --In parallel with MAXDOP 0 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 0) go The query took 1799 ms to complete.  The execution plan shows the 79360 KB of memory was granted while the estimated rows were 785594.  Sort Warnings in SQL Server Profiler.    The estimated number of rows between serial and parallel plan are the same. The parallel plan has slightly more memory granted due to additional overhead.  Intermediate Summary: The reason for the higher duration with parallel plan even with limited amount of Zip codes was sort spill. This is due to uneven distribution of employees over Zip codes, especially concentration of 49 out of 50 employees in Zip code 2001.   Now let’s update the Employees table and distribute employees evenly across all Zip codes. update Employees set Zip = EmployeeID / 400 + 1 go update statistics Employees with fullscan go Let’s execute the query serially with MAXDOP 1. --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --Serially with MAXDOP 1 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 1) go The query took 250  ms to complete.  The execution plan shows the 9016 KB of memory was granted while the estimated rows were 79973.8.  No Sort Warnings in SQL Server Profiler.  Now let’s execute the query in parallel with MAXDOP 0.  --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --In parallel with MAXDOP 0 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 0) go The query took 85 ms to complete.  The execution plan shows the 13152 KB of memory was granted while the estimated rows were 784707.  No Sort Warnings in SQL Server Profiler.    Here you see, parallel query is much faster than serial query since SQL Server is using Bitmap Filtering to eliminate rows before the hash join.   Parallel queries are very good for performance, but in some cases it can hinder performance. If one identifies the reason for these hindrances, then it is possible to get the best out of parallelism. I covered many aspects of monitoring and tuning parallel queries in webcasts (www.sqlworkshops.com/webcasts) and articles (www.sqlworkshops.com/articles). I suggest you to watch the webcasts and read the articles to better understand how to identify and tune parallel query performance issues.   Summary: One has to avoid sort spill over tempdb and the chances of spills are higher when a query executes in parallel with uneven data distribution. Parallel query brings its own advantage, reduced elapsed time and reduced work with Bitmap Filtering. So it is important to understand how to avoid spills over tempdb and when to execute a query in parallel.   I explain these concepts with detailed examples in my webcasts (www.sqlworkshops.com/webcasts), I recommend you to watch them. The best way to learn is to practice. To create the above tables and reproduce the behavior, join the mailing list at www.sqlworkshops.com/ml and I will send you the relevant SQL Scripts.   Register for the upcoming 3 Day Level 400 Microsoft SQL Server 2008 and SQL Server 2005 Performance Monitoring & Tuning Hands-on Workshop in London, United Kingdom during March 15-17, 2011, click here to register / Microsoft UK TechNet.These are hands-on workshops with a maximum of 12 participants and not lectures. For consulting engagements click here.   Disclaimer and copyright information:This article refers to organizations and products that may be the trademarks or registered trademarks of their various owners. Copyright of this article belongs to R Meyyappan / www.sqlworkshops.com. You may freely use the ideas and concepts discussed in this article with acknowledgement (www.sqlworkshops.com), but you may not claim any of it as your own work. This article is for informational purposes only; you use any of the suggestions given here entirely at your own risk.   Register for the upcoming 3 Day Level 400 Microsoft SQL Server 2008 and SQL Server 2005 Performance Monitoring & Tuning Hands-on Workshop in London, United Kingdom during March 15-17, 2011, click here to register / Microsoft UK TechNet.These are hands-on workshops with a maximum of 12 participants and not lectures. For consulting engagements click here.   R Meyyappan [email protected] LinkedIn: http://at.linkedin.com/in/rmeyyappan  

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  • It’s time that you ought to know what you don’t know

    - by fatherjack
    There is a famous quote about unknown unknowns and known knowns and so on but I’ll let you review that if you are interested. What I am worried about is that there are things going on in your environment that you ought to know about, indeed you have asked to be told about but you are not getting the information. When you schedule a SQL Agent job you can set it to send an email to an inbox monitored by someone who needs to know and indeed can do something about it. However, what happens if the email process isnt successful? Check your servers with this: USE [msdb] GO /* This code selects the top 10 most recent SQLAgent jobs that failed to complete successfully and where the email notification failed too. Jonathan Allen Jul 2012 */ DECLARE @Date DATETIME SELECT @Date = DATEADD(d, DATEDIFF(d, '19000101', GETDATE()) - 1, '19000101') SELECT TOP 10 [s].[name] , [sjh].[step_name] , [sjh].[sql_message_id] , [sjh].[sql_severity] , [sjh].[message] , [sjh].[run_date] , [sjh].[run_time] , [sjh].[run_duration] , [sjh].[operator_id_emailed] , [sjh].[operator_id_netsent] , [sjh].[operator_id_paged] , [sjh].[retries_attempted] FROM [dbo].[sysjobhistory] AS sjh INNER JOIN [dbo].[sysjobs] AS s ON [sjh].[job_id] = [s].[job_id] WHERE EXISTS ( SELECT * FROM [dbo].[sysjobs] AS s INNER JOIN [dbo].[sysjobhistory] AS s2 ON [s].[job_id] = [s2].[job_id] WHERE [sjh].[job_id] = [s2].[job_id] AND [s2].[message] LIKE '%failed to notify%' AND CONVERT(DATETIME, CONVERT(VARCHAR(15), [s2].[run_date])) >= @date AND [s2].[run_status] = 0 ) AND sjh.[run_status] = 0 AND sjh.[step_id] != 0 AND CONVERT(DATETIME, CONVERT(VARCHAR(15), [run_date])) >= @date ORDER BY [sjh].[run_date] DESC , [sjh].[run_time] DESC go USE [msdb] go /* This code summarises details of SQLAgent jobs that failed to complete successfully and where the email notification failed too. Jonathan Allen Jul 2012 */ DECLARE @Date DATETIME SELECT @Date = DATEADD(d, DATEDIFF(d, '19000101', GETDATE()) - 1, '19000101') SELECT [s].name , [s2].[step_id] , CONVERT(DATETIME, CONVERT(VARCHAR(15), [s2].[run_date])) AS [rundate] , COUNT(*) AS [execution count] FROM [dbo].[sysjobs] AS s INNER JOIN [dbo].[sysjobhistory] AS s2 ON [s].[job_id] = [s2].[job_id] WHERE [s2].[message] LIKE '%failed to notify%' AND CONVERT(DATETIME, CONVERT(VARCHAR(15), [s2].[run_date])) >= @date AND [s2].[run_status] = 0 GROUP BY name , [s2].[step_id] , [s2].[run_date] ORDER BY [s2].[run_dateDESC] These two result sets will show if there are any SQL Agent jobs that have run on your servers that failed and failed to successfully email about the failure. I hope it’s of use to you. Disclaimer – Jonathan is a Friend of Red Gate and as such, whenever they are discussed, will have a generally positive disposition towards Red Gate tools. Other tools are often available and you should always try others before you come back and buy the Red Gate ones. All code in this blog is provided “as is” and no guarantee, warranty or accuracy is applicable or inferred, run the code on a test server and be sure to understand it before you run it on a server that means a lot to you or your manager.

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  • The Art of Productivity

    - by dwahlin
    Getting things done has always been a challenge regardless of gender, age, race, skill, or job position. No matter how hard some people try, they end up procrastinating tasks until the last minute. Some people simply focus better when they know they’re out of time and can’t procrastinate any longer. How many times have you put off working on a term paper in school until the very last minute? With only a few hours left your mental energy and focus seem to kick in to high gear especially as you realize that you either get the paper done now or risk failing. It’s amazing how a little pressure can turn into a motivator and allow our minds to focus on a given task. Some people seem to specialize in procrastinating just about everything they do while others tend to be the “doers” who get a lot done and ultimately rise up the ladder at work. What’s the difference between these types of people? Is it pure laziness or are other factors at play? I think that some people are certainly more motivated than others, but I also think a lot of it is based on the process that “doers” tend to follow - whether knowingly or unknowingly. While I’ve certainly fought battles with procrastination, I’ve always had a knack for being able to get a lot done in a relatively short amount of time. I think a lot of my “get it done” attitude goes back to the the strong work ethic my parents instilled in me at a young age. I remember my dad saying, “You need to learn to work hard!” when I was around 5 years old. I remember that moment specifically because I was on a tractor with him the first time I heard it while he was trying to move some large rocks into a pile. The tractor was big but so were the rocks and my dad had to balance the tractor perfectly so that it didn’t tip forward too far. It was challenging work and somewhat tedious but my dad finished the task and taught me a few important lessons along the way including persistence, the importance of having a skill, and getting the job done right without skimping along the way. In this post I’m going to list a few of the techniques and processes I follow that I hope may be beneficial to others. I blogged about the general concept back in 2009 but thought I’d share some updated information and lessons learned since then. Most of the ideas that follow came from learning and refining my daily work process over the years. However, since most of the ideas are common sense (at least in my opinion), I suspect they can be found in other productivity processes that are out there. Let’s start off with one of the most important yet simple tips: Start Each Day with a List. Start Each Day with a List What are you planning to get done today? Do you keep track of everything in your head or rely on your calendar? While most of us think that we’re pretty good at managing “to do” lists strictly in our head you might be surprised at how affective writing out lists can be. By writing out tasks you’re forced to focus on the most important tasks to accomplish that day, commit yourself to those tasks, and have an easy way to track what was supposed to get done and what actually got done. Start every morning by making a list of specific tasks that you want to accomplish throughout the day. I’ll even go so far as to fill in times when I’d like to work on tasks if I have a lot of meetings or other events tying up my calendar on a given day. I’m not a big fan of using paper since I type a lot faster than I write (plus I write like a 3rd grader according to my wife), so I use the Sticky Notes feature available in Windows. Here’s an example of yesterday’s sticky note: What do you add to your list? That’s the subject of the next tip. Focus on Small Tasks It’s no secret that focusing on small, manageable tasks is more effective than trying to focus on large and more vague tasks. When you make your list each morning only add tasks that you can accomplish within a given time period. For example, if I only have 30 minutes blocked out to work on an article I don’t list “Write Article”. If I do that I’ll end up wasting 30 minutes stressing about how I’m going to get the article done in 30 minutes and ultimately get nothing done. Instead, I’ll list something like “Write Introductory Paragraphs for Article”. The next day I may add, “Write first section of article” or something that’s small and manageable – something I’m confident that I can get done. You’ll find that once you’ve knocked out several smaller tasks it’s easy to continue completing others since you want to keep the momentum going. In addition to keeping my tasks focused and small, I also make a conscious effort to limit my list to 4 or 5 tasks initially. I’ve found that if I list more than 5 tasks I feel a bit overwhelmed which hurts my productivity. It’s easy to add additional tasks as you complete others and you get the added benefit of that confidence boost of knowing that you’re being productive and getting things done as you remove tasks and add others. Getting Started is the Hardest (Yet Easiest) Part I’ve always found that getting started is the hardest part and one of the biggest contributors to procrastination. Getting started working on tasks is a lot like getting a large rock pushed to the bottom of a hill. It’s difficult to get the rock rolling at first, but once you manage to get it rocking some it’s really easy to get it rolling on its way to the bottom. As an example, I’ve written 100s of articles for technical magazines over the years and have really struggled with the initial introductory paragraphs. Keep in mind that these are the paragraphs that don’t really add that much value (in my opinion anyway). They introduce the reader to the subject matter and nothing more. What a waste of time for me to sit there stressing about how to start the article. On more than one occasion I’ve spent more than an hour trying to come up with 2-3 paragraphs of text.  Talk about a productivity killer! Whether you’re struggling with a writing task, some code for a project, an email, or other tasks, jumping in without thinking too much is the best way to get started I’ve found. I’m not saying that you shouldn’t have an overall plan when jumping into a task, but on some occasions you’ll find that if you simply jump into the task and stop worrying about doing everything perfectly that things will flow more smoothly. For my introductory paragraph problem I give myself 5 minutes to write out some general concepts about what I know the article will cover and then spend another 10-15 minutes going back and refining that information. That way I actually have some ideas to work with rather than a blank sheet of paper. If I still find myself struggling I’ll write the rest of the article first and then circle back to the introductory paragraphs once I’m done. To sum this tip up: Jump into a task without thinking too hard about it. It’s better to to get the rock at the top of the hill rocking some than doing nothing at all. You can always go back and refine your work.   Learn a Productivity Technique and Stick to It There are a lot of different productivity programs and seminars out there being sold by companies. I’ve always laughed at how much money people spend on some of these motivational programs/seminars because I think that being productive isn’t that hard if you create a re-useable set of steps and processes to follow. That’s not to say that some of these programs/seminars aren’t worth the money of course because I know they’ve definitely benefited some people that have a hard time getting things done and staying focused. One of the best productivity techniques I’ve ever learned is called the “Pomodoro Technique” and it’s completely free. This technique is an extremely simple way to manage your time without having to remember a bunch of steps, color coding mechanisms, or other processes. The technique was originally developed by Francesco Cirillo in the 80s and can be implemented with a simple timer. In a nutshell here’s how the technique works: Pick a task to work on Set the timer to 25 minutes and work on the task Once the timer rings record your time Take a 5 minute break Repeat the process Here’s why the technique works well for me: It forces me to focus on a single task for 25 minutes. In the past I had no time goal in mind and just worked aimlessly on a task until I got interrupted or bored. 25 minutes is a small enough chunk of time for me to stay focused. Any distractions that may come up have to wait until after the timer goes off. If the distraction is really important then I stop the timer and record my time up to that point. When the timer is running I act as if I only have 25 minutes total for the task (like you’re down to the last 25 minutes before turning in your term paper….frantically working to get it done) which helps me stay focused and turns into a “beat the clock” type of game. It’s actually kind of fun if you treat it that way and really helps me focus on a the task at hand. I automatically know how much time I’m spending on a given task (more on this later) by using this technique. I know that I have 5 minutes after each pomodoro (the 25 minute sprint) to waste on anything I’d like including visiting a website, stepping away from the computer, etc. which also helps me stay focused when the 25 minute timer is counting down. I use this technique so much that I decided to build a program for Windows 8 called Pomodoro Focus (I plan to blog about how it was built in a later post). It’s a Windows Store application that allows people to track tasks, productive time spent on tasks, interruption time experienced while working on a given task, and the number of pomodoros completed. If a time estimate is given when the task is initially created, Pomodoro Focus will also show the task completion percentage. I like it because it allows me to track my tasks, time spent on tasks (very useful in the consulting world), and even how much time I wasted on tasks (pressing the pause button while working on a task starts the interruption timer). I recently added a new feature that charts productive and interruption time for tasks since I wanted to see how productive I was from week to week and month to month. A few screenshots from the Pomodoro Focus app are shown next, I had a lot of fun building it and use it myself to as I work on tasks.   There are certainly many other productivity techniques and processes out there (and a slew of books describing them), but the Pomodoro Technique has been the simplest and most effective technique I’ve ever come across for staying focused and getting things done.   Persistence is Key Getting things done is great but one of the biggest lessons I’ve learned in life is that persistence is key especially when you’re trying to get something done that at times seems insurmountable. Small tasks ultimately lead to larger tasks getting accomplished, however, it’s not all roses along the way as some of the smaller tasks may come with their own share of bumps and bruises that lead to discouragement about the end goal and whether or not it is worth achieving at all. I’ve been on several long-term projects over my career as a software developer (I have one personal project going right now that fits well here) and found that repeating, “Persistence is the key!” over and over to myself really helps. Not every project turns out to be successful, but if you don’t show persistence through the hard times you’ll never know if you succeeded or not. Likewise, if you don’t persistently stick to the process of creating a daily list, follow a productivity process, etc. then the odds of consistently staying productive aren’t good.   Track Your Time How much time do you actually spend working on various tasks? If you don’t currently track time spent answering emails, on phone calls, and working on various tasks then you might be surprised to find out that a task that you thought was going to take you 30 minutes ultimately ended up taking 2 hours. If you don’t track the time you spend working on tasks how can you expect to learn from your mistakes, optimize your time better, and become more productive? That’s another reason why I like the Pomodoro Technique – it makes it easy to stay focused on tasks while also tracking how much time I’m working on a given task.   Eliminate Distractions I blogged about this final tip several years ago but wanted to bring it up again. If you want to be productive (and ultimately successful at whatever you’re doing) then you can’t waste a lot of time playing games or on Twitter, Facebook, or other time sucking websites. If you see an article you’re interested in that has no relation at all to the tasks you’re trying to accomplish then bookmark it and read it when you have some spare time (such as during a pomodoro break). Fighting the temptation to check your friends’ status updates on Facebook? Resist the urge and realize how much those types of activities are hurting your productivity and taking away from your focus. I’ll admit that eliminating distractions is still tough for me personally and something I have to constantly battle. But, I’ve made a conscious decision to cut back on my visits and updates to Facebook, Twitter, Google+ and other sites. Sure, my Klout score has suffered as a result lately, but does anyone actually care about those types of scores aside from your online “friends” (few of whom you’ve actually met in person)? :-) Ultimately it comes down to self-discipline and how badly you want to be productive and successful in your career, life goals, hobbies, or whatever you’re working on. Rather than having your homepage take you to a time wasting news site, game site, social site, picture site, or others, how about adding something like the following as your homepage? Every time your browser opens you’ll see a personal message which helps keep you on the right track. You can download my ubber-sophisticated homepage here if interested. Summary Is there a single set of steps that if followed can ultimately lead to productivity? I don’t think so since one size has never fit all. Every person is different, works in their own unique way, and has their own set of motivators, distractions, and more. While I certainly don’t consider myself to be an expert on the subject of productivity, I do think that if you learn what steps work best for you and gradually refine them over time that you can come up with a personal productivity process that can serve you well. Productivity is definitely an “art” that anyone can learn with a little practice and persistence. You’ve seen some of the steps that I personally like to follow and I hope you find some of them useful in boosting your productivity. If you have others you use please leave a comment. I’m always looking for ways to improve.

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  • [MISC GEEKERY] Lucid Lynx to Come Loaded with Ubuntu One Music Store

    - by Vivek
    Ubuntu 10.04 (code name Lucid Lynx) will come loaded with the Ubuntu One music store. Rhythmbox will have the Ubuntu One music store integrated in it. It’ll also allow users to download purchased music to their local machine. Ubuntu One Music Store Users will be able to access Ubuntu One music store from the sidebar of Rhythmbox. The music store is a web page that opens in the Rhythmbox player. There are albums listed on the home page of the Ubuntu One music store page. Ubuntu One music store is powered by 7digital, which is a leading digital B2B media delivery company based in London and operating globally. Canonical, the company behind Ubuntu, has partnered with 7digital to bring the music store to it’s users, integrating it with Rhythmbox and it’s cloud storage service UbuntuOne which was launched last year. The home screen of the Ubuntu One music store displays popular albums and functionality to browse and search. You can search for Artists, Tracks, Albums, or a combination of all three. Users will also be able to browse the store alphabetically, or based on different music genres. Once you select a specific artist, all their available albums are arranged in a grid. Once an album is selected, you’ll will be able to download specific songs or the whole album. You’ll also be allowed to preview different songs for 60 seconds. You’ll be able to buy tracks using a credit card or with PayPal. The purchased tracks will be visible under Library \ Purchased from Ubuntu One. The downloaded tracks are also synced with your UbuntuOne account. This means that you’ll be able to access your tracks from any where on the web. The default UbuntuOne account comes with 2 GB free storage, however, you can also purchase additional space if you need it.   All the music is in mp3 format which is not supported by default in Ubuntu. However, you can get mp3 playback functionality using GStreamer multimedia framework. Conclusion All in all the Ubuntu One music store is a positive move to enhance the user experience and also increase the popularity of Canonical in bringing Ubuntu closer to regular users. This would also provide Canonical to make some revenue in collaboration with 7digital. Ubuntu One Music Store Wiki Similar Articles Productive Geek Tips Install GIMP 2.7.1 on Lucid Lynx using PPAExaile 0.3.0 is a Music Player for UbuntuHow to install Spotify in Ubuntu 9.10 using WineAdding extra Repositories on UbuntuSpeed Up Amarok With Large Music Collections TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Open Multiple Links At One Go NachoFoto Searches Images in Real-time Office 2010 Product Guides Google Maps Place marks – Pizza, Guns or Strip Clubs Monitor Applications With Kiwi LocPDF is a Visual PDF Search Tool

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  • Software Architecture and Software Architecture Evaluation

    How many of us have worked at places where the concept of software architecture was ridiculed for wasting time and money? Even more ridiculous to them was the concept of evaluating software architecture. I think the next time that I am in this situation again, and I hope that I never am I will have to push for this methodology in the software development life cycle. I have spent way too many hours/days/months/years working poorly architected systems or systems that were just built ADHOC. This in software development must stop. I can understand why systems get like this due to overzealous sales staff, demanding management that wants everything yesterday, and project managers asking if things are done yet before the project has even started. But seriously, some time must be spent designing the applications that we write along with evaluating the architecture so that it will integrate will within the existing systems of an origination. If placed in this situation again, I will strive to gain buying from key players within the business, for example: Senior Software Engineers\Developers, Software Architects, Project Managers, Software Quality Assurance, Technical Services, Operations, and Finance in order for this idea to succeed with upper management. In order to convince these key players I will have to show them the benefits of architecture and even more benefits of evaluating software architecture on a system wide level. Benefits of Software Architecture Evaluation Places Stakeholders in the Same Room to Communicate Ensures Delivery of Detailed Quality Goals Prioritizes Conflicting Goals Requires Clear Explication Improves the Quality of Documentation Discovers Opportunities for Cross-Project Reuse Improves Architecture Practices Once I had key player buy in then and only then would I approach upper management about my plan regarding implementing the concept of software architecture and using evaluation to ensure that the software being designed is the proper architecture for the project. In addition to the benefits listed above I would also show upper management how much time is being wasted by not doing these evaluations. For example, if project X cost us Y amount, then why do we have several implementations in various forms of X and how much money and time could we have saved if we just reused the existing code base to give each system the same functionality that was already created? After this, I would mention what would happen if we had 50 instances of this situation? Then I would show them how the software architecture evaluation process would have prevented this and that the optimization could have leveraged its existing code base to increase the speed and quality of its development. References:Carnegie Mellon Software Engineering Institute (2011). Architecture Tradeoff Analysis Method from http://www.sei.cmu.edu/architecture/tools/evaluate/atam.cfm

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  • Sorting Algorithms

    - by MarkPearl
    General Every time I go back to university I find myself wading through sorting algorithms and their implementation in C++. Up to now I haven’t really appreciated their true value. However as I discovered this last week with Dictionaries in C# – having a knowledge of some basic programming principles can greatly improve the performance of a system and make one think twice about how to tackle a problem. I’m going to cover briefly in this post the following: Selection Sort Insertion Sort Shellsort Quicksort Mergesort Heapsort (not complete) Selection Sort Array based selection sort is a simple approach to sorting an unsorted array. Simply put, it repeats two basic steps to achieve a sorted collection. It starts with a collection of data and repeatedly parses it, each time sorting out one element and reducing the size of the next iteration of parsed data by one. So the first iteration would go something like this… Go through the entire array of data and find the lowest value Place the value at the front of the array The second iteration would go something like this… Go through the array from position two (position one has already been sorted with the smallest value) and find the next lowest value in the array. Place the value at the second position in the array This process would be completed until the entire array had been sorted. A positive about selection sort is that it does not make many item movements. In fact, in a worst case scenario every items is only moved once. Selection sort is however a comparison intensive sort. If you had 10 items in a collection, just to parse the collection you would have 10+9+8+7+6+5+4+3+2=54 comparisons to sort regardless of how sorted the collection was to start with. If you think about it, if you applied selection sort to a collection already sorted, you would still perform relatively the same number of iterations as if it was not sorted at all. Many of the following algorithms try and reduce the number of comparisons if the list is already sorted – leaving one with a best case and worst case scenario for comparisons. Likewise different approaches have different levels of item movement. Depending on what is more expensive, one may give priority to one approach compared to another based on what is more expensive, a comparison or a item move. Insertion Sort Insertion sort tries to reduce the number of key comparisons it performs compared to selection sort by not “doing anything” if things are sorted. Assume you had an collection of numbers in the following order… 10 18 25 30 23 17 45 35 There are 8 elements in the list. If we were to start at the front of the list – 10 18 25 & 30 are already sorted. Element 5 (23) however is smaller than element 4 (30) and so needs to be repositioned. We do this by copying the value at element 5 to a temporary holder, and then begin shifting the elements before it up one. So… Element 5 would be copied to a temporary holder 10 18 25 30 23 17 45 35 – T 23 Element 4 would shift to Element 5 10 18 25 30 30 17 45 35 – T 23 Element 3 would shift to Element 4 10 18 25 25 30 17 45 35 – T 23 Element 2 (18) is smaller than the temporary holder so we put the temporary holder value into Element 3. 10 18 23 25 30 17 45 35 – T 23   We now have a sorted list up to element 6. And so we would repeat the same process by moving element 6 to a temporary value and then shifting everything up by one from element 2 to element 5. As you can see, one major setback for this technique is the shifting values up one – this is because up to now we have been considering the collection to be an array. If however the collection was a linked list, we would not need to shift values up, but merely remove the link from the unsorted value and “reinsert” it in a sorted position. Which would reduce the number of transactions performed on the collection. So.. Insertion sort seems to perform better than selection sort – however an implementation is slightly more complicated. This is typical with most sorting algorithms – generally, greater performance leads to greater complexity. Also, insertion sort performs better if a collection of data is already sorted. If for instance you were handed a sorted collection of size n, then only n number of comparisons would need to be performed to verify that it is sorted. It’s important to note that insertion sort (array based) performs a number item moves – every time an item is “out of place” several items before it get shifted up. Shellsort – Diminishing Increment Sort So up to now we have covered Selection Sort & Insertion Sort. Selection Sort makes many comparisons and insertion sort (with an array) has the potential of making many item movements. Shellsort is an approach that takes the normal insertion sort and tries to reduce the number of item movements. In Shellsort, elements in a collection are viewed as sub-collections of a particular size. Each sub-collection is sorted so that the elements that are far apart move closer to their final position. Suppose we had a collection of 15 elements… 10 20 15 45 36 48 7 60 18 50 2 19 43 30 55 First we may view the collection as 7 sub-collections and sort each sublist, lets say at intervals of 7 10 60 55 – 20 18 – 15 50 – 45 2 – 36 19 – 48 43 – 7 30 10 55 60 – 18 20 – 15 50 – 2 45 – 19 36 – 43 48 – 7 30 (Sorted) We then sort each sublist at a smaller inter – lets say 4 10 55 60 18 – 20 15 50 2 – 45 19 36 43 – 48 7 30 10 18 55 60 – 2 15 20 50 – 19 36 43 45 – 7 30 48 (Sorted) We then sort elements at a distance of 1 (i.e. we apply a normal insertion sort) 10 18 55 60 2 15 20 50 19 36 43 45 7 30 48 2 7 10 15 18 19 20 30 36 43 45 48 50 55 (Sorted) The important thing with shellsort is deciding on the increment sequence of each sub-collection. From what I can tell, there isn’t any definitive method and depending on the order of your elements, different increment sequences may perform better than others. There are however certain increment sequences that you may want to avoid. An even based increment sequence (e.g. 2 4 8 16 32 …) should typically be avoided because it does not allow for even elements to be compared with odd elements until the final sort phase – which in a way would negate many of the benefits of using sub-collections. The performance on the number of comparisons and item movements of Shellsort is hard to determine, however it is considered to be considerably better than the normal insertion sort. Quicksort Quicksort uses a divide and conquer approach to sort a collection of items. The collection is divided into two sub-collections – and the two sub-collections are sorted and combined into one list in such a way that the combined list is sorted. The algorithm is in general pseudo code below… Divide the collection into two sub-collections Quicksort the lower sub-collection Quicksort the upper sub-collection Combine the lower & upper sub-collection together As hinted at above, quicksort uses recursion in its implementation. The real trick with quicksort is to get the lower and upper sub-collections to be of equal size. The size of a sub-collection is determined by what value the pivot is. Once a pivot is determined, one would partition to sub-collections and then repeat the process on each sub collection until you reach the base case. With quicksort, the work is done when dividing the sub-collections into lower & upper collections. The actual combining of the lower & upper sub-collections at the end is relatively simple since every element in the lower sub-collection is smaller than the smallest element in the upper sub-collection. Mergesort With quicksort, the average-case complexity was O(nlog2n) however the worst case complexity was still O(N*N). Mergesort improves on quicksort by always having a complexity of O(nlog2n) regardless of the best or worst case. So how does it do this? Mergesort makes use of the divide and conquer approach to partition a collection into two sub-collections. It then sorts each sub-collection and combines the sorted sub-collections into one sorted collection. The general algorithm for mergesort is as follows… Divide the collection into two sub-collections Mergesort the first sub-collection Mergesort the second sub-collection Merge the first sub-collection and the second sub-collection As you can see.. it still pretty much looks like quicksort – so lets see where it differs… Firstly, mergesort differs from quicksort in how it partitions the sub-collections. Instead of having a pivot – merge sort partitions each sub-collection based on size so that the first and second sub-collection of relatively the same size. This dividing keeps getting repeated until the sub-collections are the size of a single element. If a sub-collection is one element in size – it is now sorted! So the trick is how do we put all these sub-collections together so that they maintain their sorted order. Sorted sub-collections are merged into a sorted collection by comparing the elements of the sub-collection and then adjusting the sorted collection. Lets have a look at a few examples… Assume 2 sub-collections with 1 element each 10 & 20 Compare the first element of the first sub-collection with the first element of the second sub-collection. Take the smallest of the two and place it as the first element in the sorted collection. In this scenario 10 is smaller than 20 so 10 is taken from sub-collection 1 leaving that sub-collection empty, which means by default the next smallest element is in sub-collection 2 (20). So the sorted collection would be 10 20 Lets assume 2 sub-collections with 2 elements each 10 20 & 15 19 So… again we would Compare 10 with 15 – 10 is the winner so we add it to our sorted collection (10) leaving us with 20 & 15 19 Compare 20 with 15 – 15 is the winner so we add it to our sorted collection (10 15) leaving us with 20 & 19 Compare 20 with 19 – 19 is the winner so we add it to our sorted collection (10 15 19) leaving us with 20 & _ 20 is by default the winner so our sorted collection is 10 15 19 20. Make sense? Heapsort (still needs to be completed) So by now I am tired of sorting algorithms and trying to remember why they were so important. I think every year I go through this stuff I wonder to myself why are we made to learn about selection sort and insertion sort if they are so bad – why didn’t we just skip to Mergesort & Quicksort. I guess the only explanation I have for this is that sometimes you learn things so that you can implement them in future – and other times you learn things so that you know it isn’t the best way of implementing things and that you don’t need to implement it in future. Anyhow… luckily this is going to be the last one of my sorts for today. The first step in heapsort is to convert a collection of data into a heap. After the data is converted into a heap, sorting begins… So what is the definition of a heap? If we have to convert a collection of data into a heap, how do we know when it is a heap and when it is not? The definition of a heap is as follows: A heap is a list in which each element contains a key, such that the key in the element at position k in the list is at least as large as the key in the element at position 2k +1 (if it exists) and 2k + 2 (if it exists). Does that make sense? At first glance I’m thinking what the heck??? But then after re-reading my notes I see that we are doing something different – up to now we have really looked at data as an array or sequential collection of data that we need to sort – a heap represents data in a slightly different way – although the data is stored in a sequential collection, for a sequential collection of data to be in a valid heap – it is “semi sorted”. Let me try and explain a bit further with an example… Example 1 of Potential Heap Data Assume we had a collection of numbers as follows 1[1] 2[2] 3[3] 4[4] 5[5] 6[6] For this to be a valid heap element with value of 1 at position [1] needs to be greater or equal to the element at position [3] (2k +1) and position [4] (2k +2). So in the above example, the collection of numbers is not in a valid heap. Example 2 of Potential Heap Data Lets look at another collection of numbers as follows 6[1] 5[2] 4[3] 3[4] 2[5] 1[6] Is this a valid heap? Well… element with the value 6 at position 1 must be greater or equal to the element at position [3] and position [4]. Is 6 > 4 and 6 > 3? Yes it is. Lets look at element 5 as position 2. It must be greater than the values at [4] & [5]. Is 5 > 3 and 5 > 2? Yes it is. If you continued to examine this second collection of data you would find that it is in a valid heap based on the definition of a heap.

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  • How Can I Test My Computer’s Power Supply?

    - by Jason Fitzpatrick
    You’re concerned your computer troubles stem from a failing (or outright fried) power supply unit. How can you test the unit to be sure that it’s the source of your hardware headaches? Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites. The Question SuperUser reader Sam Hoice has some PSU concerns: My computer powered off the other day on its own, and now when I push the power button, nothing happens. My assumption would naturally be that the power supply is done (possibly well done) but is there any good way to test this before I buy a new one? How can Sam test things without damaging his current computer or other hardware?   The Answer SuperUser contributor Grant writes: Unplug the power supply from any of the components inside the computer (or just remove it from the computer completely). USE CAUTION HERE (Though you’d only be shocked with a max of 24 volts) Plug the power supply into the wall. Find the big 24-ish pin connector that connects to the motherboard. Connect the GREEN wire with the adjacent BLACK wire. The power supply’s fan should start up. If it doesn’t then it’s dead. If the fan starts up, then it could be the motherboard that’s dead. You can use a multimeter to check if there is power output from the power supply. Adrien offers a solution for readers who may not be comfortable jamming wires into their power supply unit’s MOBO connector: Most well-stocked geek-stores sell a “power-supply tester” that has all the appropriate connectors to plug each part of your PSU into, with spiffy LEDs indicating status of the various rails, connectors for IDE/SATA/floppy power cables, etc. They run ~$20 US. With a little careful shopping you can even find a highly-rated PSU tester for a measly $6. Have something to add to the explanation? Sound off in the the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.     

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  • Pro ASP.NET MVC Framework Review

    - by Ben Griswold
    Early in my career, when I wanted to learn a new technology, I’d sit in the bookstore aisle and I’d work my way through each of the available books on the given subject.  Put in enough time in a bookstore and you can learn just about anything. I used to really enjoy my time in the bookstore – but times have certainly changed.  Whereas books used to be the only place I could find solutions to my problems, now they may be the very last place I look.  I have been working with the ASP.NET MVC Framework for more than a year.  I have a few projects and a couple of major deployments under my belt and I was able to get up to speed with the framework without reading a single book*.  With so many resources at our fingertips (podcasts, screencasts, blogs, stackoverflow, open source projects, www.asp.net, you name it) why bother with a book? Well, I flipped through Steven Sanderson’s Pro ASP.NET MVC Framework a few months ago. And since it is prominently displayed in my co-worker’s office, I tend to pick it up as a reference from time to time.  Last week, I’m not sure why, I decided to read it cover to cover.  Man, did I eat this book up.  Granted, a lot of what I read was review, but it was only review because I had already learned lessons by piecing the puzzle together for myself via various sources. If I were starting with ASP.NET MVC (or ASP.NET Web Deployment in general) today, the first thing I would do is buy Steven Sanderson’s Pro ASP.NET MVC Framework and read it cover to cover. Steven Sanderson did such a great job with this book! As much as I appreciated the in-depth model, view, and controller talk, I was completely impressed with all the extra bits which were included.  There a was nice overview of BDD, view engine comparisons, a chapter dedicated to security and vulnerabilities, IoC, TDD and Mocking (of course), IIS deployment options and a nice overview of what the .NET platform and C# offers.  Heck, Sanderson even include bits about webforms! The book is fantastic and I highly recommend it – even if you think you’ve already got your head around ASP.NET MVC.  By the way, procrastinators may be in luck.  ASP.NET MVC V2 Framework can be pre-ordered.  You might want to jump right into the second edition and find out what Sanderson has to say about MVC 2. * Actually, I did read through the free bits of Professional ASP.NET MVC 1.0.  But it was just a chapter – albeit a really long chapter.

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