Search Results

Search found 1469 results on 59 pages for 'favorite'.

Page 55/59 | < Previous Page | 51 52 53 54 55 56 57 58 59  | Next Page >

  • C#: Optional Parameters - Pros and Pitfalls

    - by James Michael Hare
    When Microsoft rolled out Visual Studio 2010 with C# 4, I was very excited to learn how I could apply all the new features and enhancements to help make me and my team more productive developers. Default parameters have been around forever in C++, and were intentionally omitted in Java in favor of using overloading to satisfy that need as it was though that having too many default parameters could introduce code safety issues.  To some extent I can understand that move, as I’ve been bitten by default parameter pitfalls before, but at the same time I feel like Java threw out the baby with the bathwater in that move and I’m glad to see C# now has them. This post briefly discusses the pros and pitfalls of using default parameters.  I’m avoiding saying cons, because I really don’t believe using default parameters is a negative thing, I just think there are things you must watch for and guard against to avoid abuses that can cause code safety issues. Pro: Default Parameters Can Simplify Code Let’s start out with positives.  Consider how much cleaner it is to reduce all the overloads in methods or constructors that simply exist to give the semblance of optional parameters.  For example, we could have a Message class defined which allows for all possible initializations of a Message: 1: public class Message 2: { 3: // can either cascade these like this or duplicate the defaults (which can introduce risk) 4: public Message() 5: : this(string.Empty) 6: { 7: } 8:  9: public Message(string text) 10: : this(text, null) 11: { 12: } 13:  14: public Message(string text, IDictionary<string, string> properties) 15: : this(text, properties, -1) 16: { 17: } 18:  19: public Message(string text, IDictionary<string, string> properties, long timeToLive) 20: { 21: // ... 22: } 23: }   Now consider the same code with default parameters: 1: public class Message 2: { 3: // can either cascade these like this or duplicate the defaults (which can introduce risk) 4: public Message(string text = "", IDictionary<string, string> properties = null, long timeToLive = -1) 5: { 6: // ... 7: } 8: }   Much more clean and concise and no repetitive coding!  In addition, in the past if you wanted to be able to cleanly supply timeToLive and accept the default on text and properties above, you would need to either create another overload, or pass in the defaults explicitly.  With named parameters, though, we can do this easily: 1: var msg = new Message(timeToLive: 100);   Pro: Named Parameters can Improve Readability I must say one of my favorite things with the default parameters addition in C# is the named parameters.  It lets code be a lot easier to understand visually with no comments.  Think how many times you’ve run across a TimeSpan declaration with 4 arguments and wondered if they were passing in days/hours/minutes/seconds or hours/minutes/seconds/milliseconds.  A novice running through your code may wonder what it is.  Named arguments can help resolve the visual ambiguity: 1: // is this days/hours/minutes/seconds (no) or hours/minutes/seconds/milliseconds (yes) 2: var ts = new TimeSpan(1, 2, 3, 4); 3:  4: // this however is visually very explicit 5: var ts = new TimeSpan(days: 1, hours: 2, minutes: 3, seconds: 4);   Or think of the times you’ve run across something passing a Boolean literal and wondered what it was: 1: // what is false here? 2: var sub = CreateSubscriber(hostname, port, false); 3:  4: // aha! Much more visibly clear 5: var sub = CreateSubscriber(hostname, port, isBuffered: false);   Pitfall: Don't Insert new Default Parameters In Between Existing Defaults Now let’s consider a two potential pitfalls.  The first is really an abuse.  It’s not really a fault of the default parameters themselves, but a fault in the use of them.  Let’s consider that Message constructor again with defaults.  Let’s say you want to add a messagePriority to the message and you think this is more important than a timeToLive value, so you decide to put messagePriority before it in the default, this gives you: 1: public class Message 2: { 3: public Message(string text = "", IDictionary<string, string> properties = null, int priority = 5, long timeToLive = -1) 4: { 5: // ... 6: } 7: }   Oh boy have we set ourselves up for failure!  Why?  Think of all the code out there that could already be using the library that already specified the timeToLive, such as this possible call: 1: var msg = new Message(“An error occurred”, myProperties, 1000);   Before this specified a message with a TTL of 1000, now it specifies a message with a priority of 1000 and a time to live of -1 (infinite).  All of this with NO compiler errors or warnings. So the rule to take away is if you are adding new default parameters to a method that’s currently in use, make sure you add them to the end of the list or create a brand new method or overload. Pitfall: Beware of Default Parameters in Inheritance and Interface Implementation Now, the second potential pitfalls has to do with inheritance and interface implementation.  I’ll illustrate with a puzzle: 1: public interface ITag 2: { 3: void WriteTag(string tagName = "ITag"); 4: } 5:  6: public class BaseTag : ITag 7: { 8: public virtual void WriteTag(string tagName = "BaseTag") { Console.WriteLine(tagName); } 9: } 10:  11: public class SubTag : BaseTag 12: { 13: public override void WriteTag(string tagName = "SubTag") { Console.WriteLine(tagName); } 14: } 15:  16: public static class Program 17: { 18: public static void Main() 19: { 20: SubTag subTag = new SubTag(); 21: BaseTag subByBaseTag = subTag; 22: ITag subByInterfaceTag = subTag; 23:  24: // what happens here? 25: subTag.WriteTag(); 26: subByBaseTag.WriteTag(); 27: subByInterfaceTag.WriteTag(); 28: } 29: }   What happens?  Well, even though the object in each case is SubTag whose tag is “SubTag”, you will get: 1: SubTag 2: BaseTag 3: ITag   Why?  Because default parameter are resolved at compile time, not runtime!  This means that the default does not belong to the object being called, but by the reference type it’s being called through.  Since the SubTag instance is being called through an ITag reference, it will use the default specified in ITag. So the moral of the story here is to be very careful how you specify defaults in interfaces or inheritance hierarchies.  I would suggest avoiding repeating them, and instead concentrating on the layer of classes or interfaces you must likely expect your caller to be calling from. For example, if you have a messaging factory that returns an IMessage which can be either an MsmqMessage or JmsMessage, it only makes since to put the defaults at the IMessage level since chances are your user will be using the interface only. So let’s sum up.  In general, I really love default and named parameters in C# 4.0.  I think they’re a great tool to help make your code easier to read and maintain when used correctly. On the plus side, default parameters: Reduce redundant overloading for the sake of providing optional calling structures. Improve readability by being able to name an ambiguous argument. But remember to make sure you: Do not insert new default parameters in the middle of an existing set of default parameters, this may cause unpredictable behavior that may not necessarily throw a syntax error – add to end of list or create new method. Be extremely careful how you use default parameters in inheritance hierarchies and interfaces – choose the most appropriate level to add the defaults based on expected usage. Technorati Tags: C#,.NET,Software,Default Parameters

    Read the article

  • Who is Jeremiah Owyang?

    - by Michael Hylton
    12.00 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Q: What’s your current role and what career path brought you here? J.O.: I'm currently a partner and one of the founding team members at Altimeter Group.  I'm currently the Research Director, as well as wear the hat of Industry Analyst. Prior to joining Altimeter, I was an Industry Analyst at Forrester covering Social Computing, and before that, deployed and managed the social media program at Hitachi Data Systems in Santa Clara.  Around that time, I started a career blog called Web Strategy which focused on how companies were using the web to connect with customers --and never looked back. Q: As an industry analyst, what are you focused on these days? J.O.: There are three trends that I'm focused my research on at this time:  1) The Dynamic Customer Journey:  Individuals (both b2c and b2b) are given so many options in their sources of data, channels to choose from and screens to consume them on that we've found that at each given touchpoint there are 75 potential permutations.  Companies that can map this, then deliver information to individuals when they need it will have a competitive advantage and we want to find out who's doing this.  2) One of the sub themes that supports this trend is Social Performance.  Yesterday's social web was disparate engagement of humans, but the next phase will be data driven, and soon new technologies will emerge to help all those that are consuming, publishing, and engaging on the social web to be more efficient with their time through forms of automation.  As you might expect, this comes with upsides and downsides.  3) The Sentient World is our research theme that looks out the furthest as the world around us (even inanimate objects) become 'self aware' and are able to talk back to us via digital devices and beyond.  Big data, internet of things, mobile devices will all be this next set. Q: People cite that the line between work and life is getting more and more blurred. Do you see your personal life influencing your professional work? J.O.: The lines between our work and personal lives are dissolving, and this leads to a greater upside of being always connected and have deeper relationships with those that are not.  It also means a downside of society expectations that we're always around and available for colleagues, customers, and beyond.  In the future, a balance will be sought as we seek to achieve the goals of family, friends, work, and our own personal desires.  All of this is being ironically written at 430 am on a Sunday am.  Q: How can people keep up with what you’re working on? J.O.: A great question, thanks.  There are a few sources of information to find out, I'll lead with the first which is my blog at web-strategist.com.  A few times a week I'll publish my industry insights (hires, trends, forces, funding, M&A, business needs) as well as on twitter where I'll point to all the news that's fit to print @jowyang.  As my research reports go live (we publish them for all to read --called Open Research-- at no cost) they'll emerge on my blog, or checkout the research tab to find out more now.  http://www.web-strategist.com/blog/research/ Q: Recently, you’ve been working with us here at Oracle on something exciting coming up later this week. What’s on the horizon?  J.O.: Absolutely! This coming Thursday, September 13th, I’m doing a webcast with Oracle on “Managing Social Relationships for the Enterprise”. This is going to be a great discussion with Reggie Bradford, Senior Vice President of Product Development at Oracle and Christian Finn, Senior Director of Product Management for Oracle WebCenter. I’m looking forward to a great discussion around all those issues that so many companies are struggling with these days as they realize how much social media is impacting their business. It’s changing the way your customers and employees interact with your brand. Today it’s no longer a matter of when to become a social-enabled enterprise, but how to become a successful one. 12.00 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Q: You’ve been very actively pursued for media interviews and conference and company speaking engagements – anything you’d like to share to give us a sneak peak of what to expect on Thursday’s webcast?  J.O.: Below is a 15 minute video which encapsulates Altimeter’s themes on the Dynamic Customer Journey and the Sentient World. I’m really proud to have taken an active role in the first ever LeWeb outside of Paris. This one, which was featured in downtown London across the street from Westminster Abbey was sold out. If you’ve not heard of LeWeb, this is a global Internet conference hosted by Loic and Geraldine Le Meur, a power couple that stem from Paris but are also living in Silicon Valley, this is one of my favorite conferences to connect with brands, technology innovators, investors and friends. Altimeter was able to play a minor role in suggesting the theme for the event “Faster Than Real Time” which stems off previous LeWebs that focused on the “Real time web”. In this radical state, companies are able to anticipate the needs of their customers by using data, technology, and devices and deliver meaningful experiences before customers even know they need it. I explore two of three of Altimeter’s research themes, the Dynamic Customer Journey, and the Sentient World in my speech, but due to time, did not focus on Adaptive Organization.

    Read the article

  • Who is Jeremiah Owyang?

    - by Michael Snow
    12.00 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Q: What’s your current role and what career path brought you here? J.O.: I'm currently a partner and one of the founding team members at Altimeter Group.  I'm currently the Research Director, as well as wear the hat of Industry Analyst. Prior to joining Altimeter, I was an Industry Analyst at Forrester covering Social Computing, and before that, deployed and managed the social media program at Hitachi Data Systems in Santa Clara.  Around that time, I started a career blog called Web Strategy which focused on how companies were using the web to connect with customers --and never looked back. Q: As an industry analyst, what are you focused on these days? J.O.: There are three trends that I'm focused my research on at this time:  1) The Dynamic Customer Journey:  Individuals (both b2c and b2b) are given so many options in their sources of data, channels to choose from and screens to consume them on that we've found that at each given touchpoint there are 75 potential permutations.  Companies that can map this, then deliver information to individuals when they need it will have a competitive advantage and we want to find out who's doing this.  2) One of the sub themes that supports this trend is Social Performance.  Yesterday's social web was disparate engagement of humans, but the next phase will be data driven, and soon new technologies will emerge to help all those that are consuming, publishing, and engaging on the social web to be more efficient with their time through forms of automation.  As you might expect, this comes with upsides and downsides.  3) The Sentient World is our research theme that looks out the furthest as the world around us (even inanimate objects) become 'self aware' and are able to talk back to us via digital devices and beyond.  Big data, internet of things, mobile devices will all be this next set. Q: People cite that the line between work and life is getting more and more blurred. Do you see your personal life influencing your professional work? J.O.: The lines between our work and personal lives are dissolving, and this leads to a greater upside of being always connected and have deeper relationships with those that are not.  It also means a downside of society expectations that we're always around and available for colleagues, customers, and beyond.  In the future, a balance will be sought as we seek to achieve the goals of family, friends, work, and our own personal desires.  All of this is being ironically written at 430 am on a Sunday am.  Q: How can people keep up with what you’re working on? J.O.: A great question, thanks.  There are a few sources of information to find out, I'll lead with the first which is my blog at web-strategist.com.  A few times a week I'll publish my industry insights (hires, trends, forces, funding, M&A, business needs) as well as on twitter where I'll point to all the news that's fit to print @jowyang.  As my research reports go live (we publish them for all to read --called Open Research-- at no cost) they'll emerge on my blog, or checkout the research tab to find out more now.  http://www.web-strategist.com/blog/research/ Q: Recently, you’ve been working with us here at Oracle on something exciting coming up later this week. What’s on the horizon?  J.O.: Absolutely! This coming Thursday, September 13th, I’m doing a webcast with Oracle on “Managing Social Relationships for the Enterprise”. This is going to be a great discussion with Reggie Bradford, Senior Vice President of Product Development at Oracle and Christian Finn, Senior Director of Product Management for Oracle WebCenter. I’m looking forward to a great discussion around all those issues that so many companies are struggling with these days as they realize how much social media is impacting their business. It’s changing the way your customers and employees interact with your brand. Today it’s no longer a matter of when to become a social-enabled enterprise, but how to become a successful one. 12.00 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-bidi-font-family:"Times New Roman";} Q: You’ve been very actively pursued for media interviews and conference and company speaking engagements – anything you’d like to share to give us a sneak peak of what to expect on Thursday’s webcast?  J.O.: Below is a 15 minute video which encapsulates Altimeter’s themes on the Dynamic Customer Journey and the Sentient World. I’m really proud to have taken an active role in the first ever LeWeb outside of Paris. This one, which was featured in downtown London across the street from Westminster Abbey was sold out. If you’ve not heard of LeWeb, this is a global Internet conference hosted by Loic and Geraldine Le Meur, a power couple that stem from Paris but are also living in Silicon Valley, this is one of my favorite conferences to connect with brands, technology innovators, investors and friends. Altimeter was able to play a minor role in suggesting the theme for the event “Faster Than Real Time” which stems off previous LeWebs that focused on the “Real time web”. In this radical state, companies are able to anticipate the needs of their customers by using data, technology, and devices and deliver meaningful experiences before customers even know they need it. I explore two of three of Altimeter’s research themes, the Dynamic Customer Journey, and the Sentient World in my speech, but due to time, did not focus on Adaptive Organization.

    Read the article

  • Process.Start() and ShellExecute() fails with URLs on Windows 8

    - by Rick Strahl
    Since I installed Windows 8 I've noticed that a number of my applications appear to have problems opening URLs. That is when I click on a link inside of a Windows application, either nothing happens or there's an error that occurs. It's happening both to my own applications and a host of Windows applications I'm running. At first I thought this was an issue with my default browser (Chrome) but after switching the default browser to a few others and experimenting a bit I noticed that the errors occur - oddly enough - only when I run an application as an Administrator. I also tried switching to FireFox and Opera as my default browser and saw exactly the same behavior. The scenario for this is a bit bizarre: Running on Windows 8 Call Process.Start() (or ShellExecute() in Win32 API) with a URL or an HTML file Run 'As Administrator' (works fine under non-elevated user account!) or with UAC off A browser other than Internet Explorer is set as your Default Web Browser Talk about a weird scenario: Something that doesn't work when you run as an Administrator which is supposed to have rights to everything on the system! Instead running under an Admin account - either elevated with a User Account Control prompt or even when running as a full Administrator fails. It appears that this problem does not occur for everyone, but when I looked for a solution to this, I saw quite a few posts in relation to this with no clear resolutions. I have three Windows 8 machines running here in the office and all three of them showed this behavior. Lest you think this is just a programmer's problem - this can affect any software running on your system that needs to run under administrative rights. Try it out Now, in order for this next example to fail, any browser but Internet Explorer has to be your default browser and even then it may not fail depending on how you installed your browser. To see if this is a problem create a small Console application and call Process.Start() with a URL in it:namespace Win8ShellBugConsole { class Program { static void Main(string[] args) { Console.WriteLine("Launching Url..."); Process.Start("http://microsoft.com"); Console.Write("Press any key to continue..."); Console.ReadKey(); Console.WriteLine("\r\n\r\nLaunching image..."); Process.Start(Path.GetFullPath(@"..\..\sailbig.jpg")); Console.Write("Press any key to continue..."); Console.ReadKey(); } } } Compile this code. Then execute the code from Explorer (not from Visual Studio because that may change the permissions). If you simply run the EXE and you're not running as an administrator, you'll see the Web page pop up in the browser as well as the image loading. Now run the same thing with Run As Administrator: Now when you run it you get a nice error when Process.Start() is fired: The same happens if you are running with User Account Control off altogether - ie. you are running as a full admin account. Now if you comment out the URL in the code above and just fire the image display - that works just fine in any user mode. As does opening any other local file type or even starting a new EXE locally (ie. Process.Start("c:\windows\notepad.exe"). All that works, EXCEPT for URLs. The code above uses Process.Start() in .NET but the same happens in Win32 Applications that use the ShellExecute API. In some of my older Fox apps ShellExecute returns an error code of 31 - which is No Shell Association found. What's the Deal? It turns out the problem has to do with the way browsers are registering themselves on Windows. Internet Explorer - being a built-in application in Windows 8 - apparently does this correctly, but other browsers possibly don't or at least didn't at the time I installed them. So even Chrome, which continually updates itself, has a recent version that apparently has this registration issue fixed, I was unable to simply set IE as my default browser then use Chrome to 'Set as Default Browser'. It still didn't work. Neither did using the Set Program Associations dialog which lets you assign what extensions are mapped to by a given application. Each application provides a set of extension/moniker mappings that it supports and this dialog lets you associate them on a system wide basis. This also did not work for Chrome or any of the other browsers at first. However, after repeated retries here eventually I did manage to get FireFox to work, but not any of the others. What Works? Reinstall the Browser In the end I decided on the hard core pull the plug solution: Totally uninstall and re-install Chrome in this case. And lo and behold, after reinstall everything was working fine. Now even removing the association for Chrome, switching to IE as the default browser and then back to Chrome works. But, even though the version of Chrome I was running before uninstalling and reinstalling is the same as I'm running now after the reinstall now it works. Of course I had to find out the hard way, before Richard commented with a note regarding what the issue is with Chrome at least: http://code.google.com/p/chromium/issues/detail?id=156400 As expected the issue is a registration issue - with keys not being registered at the machine level. Reading this I'm still not sure why this should be a problem - an elevated account still runs under the same user account (ie. I'm still rickstrahl even if I Run As Administrator), so why shouldn't an app be able to read my Current User registry hive? And also that doesn't quite explain why if I register the extensions using Run As Administrator in Chrome when using Set as Default Browser). But in the end it works… Not so fast It's now a couple of days later and still there are some oddball problems although this time they appear to be purely Chrome issues. After the reinstall Chrome seems to pop up properly with ShellExecute() calls both in regular user and Admin mode. However, it now looks like Chrome is actually running two completely separate user profiles for each. For example, when I run Visual Studio in Admin mode and go to View in browser, Chrome complains that it was installed in Admin mode and can't launch (WTF?). Then you retry a few times later and it ends up working. When launched that way some of the plug-ins installed don't show up with the effect that sometimes they're visible sometimes they're not. Also Chrome seems to loose my configuration and Google sign in between sessions now, presumably when switching user modes. Add-ins installed in admin mode don't show up in user mode and vice versa. Ah, this is lovely. Did I mention that I freaking hate UAC precisely because of this kind of bullshit. You can never tell exactly what account your app is running under, and apparently apps also have a hard time trying to put data into the right place that works for both scenarios. And as my recent post on using Windows Live accounts shows it's yet another level of abstraction ontop of the underlying system identity that can cause all sort of small side effect headaches like this. Hopefully, most of you are skirting this issue altogether - having installed more recent versions of your favorite browsers. If not, hopefully this post will take you straight to reinstallation to fix this annoying issue.© Rick Strahl, West Wind Technologies, 2005-2012Posted in Windows  .NET   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

    Read the article

  • Of C# Iterators and Performance

    - by James Michael Hare
    Some of you reading this will be wondering, "what is an iterator" and think I'm locked in the world of C++.  Nope, I'm talking C# iterators.  No, not enumerators, iterators.   So, for those of you who do not know what iterators are in C#, I will explain it in summary, and for those of you who know what iterators are but are curious of the performance impacts, I will explore that as well.   Iterators have been around for a bit now, and there are still a bunch of people who don't know what they are or what they do.  I don't know how many times at work I've had a code review on my code and have someone ask me, "what's that yield word do?"   Basically, this post came to me as I was writing some extension methods to extend IEnumerable<T> -- I'll post some of the fun ones in a later post.  Since I was filtering the resulting list down, I was using the standard C# iterator concept; but that got me wondering: what are the performance implications of using an iterator versus returning a new enumeration?   So, to begin, let's look at a couple of methods.  This is a new (albeit contrived) method called Every(...).  The goal of this method is to access and enumeration and return every nth item in the enumeration (including the first).  So Every(2) would return items 0, 2, 4, 6, etc.   Now, if you wanted to write this in the traditional way, you may come up with something like this:       public static IEnumerable<T> Every<T>(this IEnumerable<T> list, int interval)     {         List<T> newList = new List<T>();         int count = 0;           foreach (var i in list)         {             if ((count++ % interval) == 0)             {                 newList.Add(i);             }         }           return newList;     }     So basically this method takes any IEnumerable<T> and returns a new IEnumerable<T> that contains every nth item.  Pretty straight forward.   The problem?  Well, Every<T>(...) will construct a list containing every nth item whether or not you care.  What happens if you were searching this result for a certain item and find that item after five tries?  You would have generated the rest of the list for nothing.   Enter iterators.  This C# construct uses the yield keyword to effectively defer evaluation of the next item until it is asked for.  This can be very handy if the evaluation itself is expensive or if there's a fair chance you'll never want to fully evaluate a list.   We see this all the time in Linq, where many expressions are chained together to do complex processing on a list.  This would be very expensive if each of these expressions evaluated their entire possible result set on call.    Let's look at the same example function, this time using an iterator:       public static IEnumerable<T> Every<T>(this IEnumerable<T> list, int interval)     {         int count = 0;         foreach (var i in list)         {             if ((count++ % interval) == 0)             {                 yield return i;             }         }     }   Notice it does not create a new return value explicitly, the only evidence of a return is the "yield return" statement.  What this means is that when an item is requested from the enumeration, it will enter this method and evaluate until it either hits a yield return (in which case that item is returned) or until it exits the method or hits a yield break (in which case the iteration ends.   Behind the scenes, this is all done with a class that the CLR creates behind the scenes that keeps track of the state of the iteration, so that every time the next item is asked for, it finds that item and then updates the current position so it knows where to start at next time.   It doesn't seem like a big deal, does it?  But keep in mind the key point here: it only returns items as they are requested. Thus if there's a good chance you will only process a portion of the return list and/or if the evaluation of each item is expensive, an iterator may be of benefit.   This is especially true if you intend your methods to be chainable similar to the way Linq methods can be chained.    For example, perhaps you have a List<int> and you want to take every tenth one until you find one greater than 10.  We could write that as:       List<int> someList = new List<int>();         // fill list here         someList.Every(10).TakeWhile(i => i <= 10);     Now is the difference more apparent?  If we use the first form of Every that makes a copy of the list.  It's going to copy the entire list whether we will need those items or not, that can be costly!    With the iterator version, however, it will only take items from the list until it finds one that is > 10, at which point no further items in the list are evaluated.   So, sounds neat eh?  But what's the cost is what you're probably wondering.  So I ran some tests using the two forms of Every above on lists varying from 5 to 500,000 integers and tried various things.    Now, iteration isn't free.  If you are more likely than not to iterate the entire collection every time, iterator has some very slight overhead:   Copy vs Iterator on 100% of Collection (10,000 iterations) Collection Size Num Iterated Type Total ms 5 5 Copy 5 5 5 Iterator 5 50 50 Copy 28 50 50 Iterator 27 500 500 Copy 227 500 500 Iterator 247 5000 5000 Copy 2266 5000 5000 Iterator 2444 50,000 50,000 Copy 24,443 50,000 50,000 Iterator 24,719 500,000 500,000 Copy 250,024 500,000 500,000 Iterator 251,521   Notice that when iterating over the entire produced list, the times for the iterator are a little better for smaller lists, then getting just a slight bit worse for larger lists.  In reality, given the number of items and iterations, the result is near negligible, but just to show that iterators come at a price.  However, it should also be noted that the form of Every that returns a copy will have a left-over collection to garbage collect.   However, if we only partially evaluate less and less through the list, the savings start to show and make it well worth the overhead.  Let's look at what happens if you stop looking after 80% of the list:   Copy vs Iterator on 80% of Collection (10,000 iterations) Collection Size Num Iterated Type Total ms 5 4 Copy 5 5 4 Iterator 5 50 40 Copy 27 50 40 Iterator 23 500 400 Copy 215 500 400 Iterator 200 5000 4000 Copy 2099 5000 4000 Iterator 1962 50,000 40,000 Copy 22,385 50,000 40,000 Iterator 19,599 500,000 400,000 Copy 236,427 500,000 400,000 Iterator 196,010       Notice that the iterator form is now operating quite a bit faster.  But the savings really add up if you stop on average at 50% (which most searches would typically do):     Copy vs Iterator on 50% of Collection (10,000 iterations) Collection Size Num Iterated Type Total ms 5 2 Copy 5 5 2 Iterator 4 50 25 Copy 25 50 25 Iterator 16 500 250 Copy 188 500 250 Iterator 126 5000 2500 Copy 1854 5000 2500 Iterator 1226 50,000 25,000 Copy 19,839 50,000 25,000 Iterator 12,233 500,000 250,000 Copy 208,667 500,000 250,000 Iterator 122,336   Now we see that if we only expect to go on average 50% into the results, we tend to shave off around 40% of the time.  And this is only for one level deep.  If we are using this in a chain of query expressions it only adds to the savings.   So my recommendation?  If you have a resonable expectation that someone may only want to partially consume your enumerable result, I would always tend to favor an iterator.  The cost if they iterate the whole thing does not add much at all -- and if they consume only partially, you reap some really good performance gains.   Next time I'll discuss some of my favorite extensions I've created to make development life a little easier and maintainability a little better.

    Read the article

  • Thread placement policies on NUMA systems - update

    - by Dave
    In a prior blog entry I noted that Solaris used a "maximum dispersal" placement policy to assign nascent threads to their initial processors. The general idea is that threads should be placed as far away from each other as possible in the resource topology in order to reduce resource contention between concurrently running threads. This policy assumes that resource contention -- pipelines, memory channel contention, destructive interference in the shared caches, etc -- will likely outweigh (a) any potential communication benefits we might achieve by packing our threads more densely onto a subset of the NUMA nodes, and (b) benefits of NUMA affinity between memory allocated by one thread and accessed by other threads. We want our threads spread widely over the system and not packed together. Conceptually, when placing a new thread, the kernel picks the least loaded node NUMA node (the node with lowest aggregate load average), and then the least loaded core on that node, etc. Furthermore, the kernel places threads onto resources -- sockets, cores, pipelines, etc -- without regard to the thread's process membership. That is, initial placement is process-agnostic. Keep reading, though. This description is incorrect. On Solaris 10 on a SPARC T5440 with 4 x T2+ NUMA nodes, if the system is otherwise unloaded and we launch a process that creates 20 compute-bound concurrent threads, then typically we'll see a perfect balance with 5 threads on each node. We see similar behavior on an 8-node x86 x4800 system, where each node has 8 cores and each core is 2-way hyperthreaded. So far so good; this behavior seems in agreement with the policy I described in the 1st paragraph. I recently tried the same experiment on a 4-node T4-4 running Solaris 11. Both the T5440 and T4-4 are 4-node systems that expose 256 logical thread contexts. To my surprise, all 20 threads were placed onto just one NUMA node while the other 3 nodes remained completely idle. I checked the usual suspects such as processor sets inadvertently left around by colleagues, processors left offline, and power management policies, but the system was configured normally. I then launched multiple concurrent instances of the process, and, interestingly, all the threads from the 1st process landed on one node, all the threads from the 2nd process landed on another node, and so on. This happened even if I interleaved thread creating between the processes, so I was relatively sure the effect didn't related to thread creation time, but rather that placement was a function of process membership. I this point I consulted the Solaris sources and talked with folks in the Solaris group. The new Solaris 11 behavior is intentional. The kernel is no longer using a simple maximum dispersal policy, and thread placement is process membership-aware. Now, even if other nodes are completely unloaded, the kernel will still try to pack new threads onto the home lgroup (socket) of the primordial thread until the load average of that node reaches 50%, after which it will pick the next least loaded node as the process's new favorite node for placement. On the T4-4 we have 64 logical thread contexts (strands) per socket (lgroup), so if we launch 48 concurrent threads we will find 32 placed on one node and 16 on some other node. If we launch 64 threads we'll find 32 and 32. That means we can end up with our threads clustered on a small subset of the nodes in a way that's quite different that what we've seen on Solaris 10. So we have a policy that allows process-aware packing but reverts to spreading threads onto other nodes if a node becomes too saturated. It turns out this policy was enabled in Solaris 10, but certain bugs suppressed the mixed packing/spreading behavior. There are configuration variables in /etc/system that allow us to dial the affinity between nascent threads and their primordial thread up and down: see lgrp_expand_proc_thresh, specifically. In the OpenSolaris source code the key routine is mpo_update_tunables(). This method reads the /etc/system variables and sets up some global variables that will subsequently be used by the dispatcher, which calls lgrp_choose() in lgrp.c to place nascent threads. Lgrp_expand_proc_thresh controls how loaded an lgroup must be before we'll consider homing a process's threads to another lgroup. Tune this value lower to have it spread your process's threads out more. To recap, the 'new' policy is as follows. Threads from the same process are packed onto a subset of the strands of a socket (50% for T-series). Once that socket reaches the 50% threshold the kernel then picks another preferred socket for that process. Threads from unrelated processes are spread across sockets. More precisely, different processes may have different preferred sockets (lgroups). Beware that I've simplified and elided details for the purposes of explication. The truth is in the code. Remarks: It's worth noting that initial thread placement is just that. If there's a gross imbalance between the load on different nodes then the kernel will migrate threads to achieve a better and more even distribution over the set of available nodes. Once a thread runs and gains some affinity for a node, however, it becomes "stickier" under the assumption that the thread has residual cache residency on that node, and that memory allocated by that thread resides on that node given the default "first-touch" page-level NUMA allocation policy. Exactly how the various policies interact and which have precedence under what circumstances could the topic of a future blog entry. The scheduler is work-conserving. The x4800 mentioned above is an interesting system. Each of the 8 sockets houses an Intel 7500-series processor. Each processor has 3 coherent QPI links and the system is arranged as a glueless 8-socket twisted ladder "mobius" topology. Nodes are either 1 or 2 hops distant over the QPI links. As an aside the mapping of logical CPUIDs to physical resources is rather interesting on Solaris/x4800. On SPARC/Solaris the CPUID layout is strictly geographic, with the highest order bits identifying the socket, the next lower bits identifying the core within that socket, following by the pipeline (if present) and finally the logical thread context ("strand") on the core. But on Solaris on the x4800 the CPUID layout is as follows. [6:6] identifies the hyperthread on a core; bits [5:3] identify the socket, or package in Intel terminology; bits [2:0] identify the core within a socket. Such low-level details should be of interest only if you're binding threads -- a bad idea, the kernel typically handles placement best -- or if you're writing NUMA-aware code that's aware of the ambient placement and makes decisions accordingly. Solaris introduced the so-called critical-threads mechanism, which is expressed by putting a thread into the FX scheduling class at priority 60. The critical-threads mechanism applies to placement on cores, not on sockets, however. That is, it's an intra-socket policy, not an inter-socket policy. Solaris 11 introduces the Power Aware Dispatcher (PAD) which packs threads instead of spreading them out in an attempt to be able to keep sockets or cores at lower power levels. Maximum dispersal may be good for performance but is anathema to power management. PAD is off by default, but power management polices constitute yet another confounding factor with respect to scheduling and dispatching. If your threads communicate heavily -- one thread reads cache lines last written by some other thread -- then the new dense packing policy may improve performance by reducing traffic on the coherent interconnect. On the other hand if your threads in your process communicate rarely, then it's possible the new packing policy might result on contention on shared computing resources. Unfortunately there's no simple litmus test that says whether packing or spreading is optimal in a given situation. The answer varies by system load, application, number of threads, and platform hardware characteristics. Currently we don't have the necessary tools and sensoria to decide at runtime, so we're reduced to an empirical approach where we run trials and try to decide on a placement policy. The situation is quite frustrating. Relatedly, it's often hard to determine just the right level of concurrency to optimize throughput. (Understanding constructive vs destructive interference in the shared caches would be a good start. We could augment the lines with a small tag field indicating which strand last installed or accessed a line. Given that, we could augment the CPU with performance counters for misses where a thread evicts a line it installed vs misses where a thread displaces a line installed by some other thread.)

    Read the article

  • Try a sample: Using the counter predicate for event sampling

    - by extended_events
    Extended Events offers a rich filtering mechanism, called predicates, that allows you to reduce the number of events you collect by specifying criteria that will be applied during event collection. (You can find more information about predicates in Using SQL Server 2008 Extended Events (by Jonathan Kehayias)) By evaluating predicates early in the event firing sequence we can reduce the performance impact of collecting events by stopping event collection when the criteria are not met. You can specify predicates on both event fields and on a special object called a predicate source. Predicate sources are similar to action in that they typically are related to some type of global information available from the server. You will find that many of the actions available in Extended Events have equivalent predicate sources, but actions and predicates sources are not the same thing. Applying predicates, whether on a field or predicate source, is very similar to what you are used to in T-SQL in terms of how they work; you pick some field/source and compare it to a value, for example, session_id = 52. There is one predicate source that merits special attention though, not just for its special use, but for how the order of predicate evaluation impacts the behavior you see. I’m referring to the counter predicate source. The counter predicate source gives you a way to sample a subset of events that otherwise meet the criteria of the predicate; for example you could collect every other event, or only every tenth event. Simple CountingThe counter predicate source works by creating an in memory counter that increments every time the predicate statement is evaluated. Here is a simple example with my favorite event, sql_statement_completed, that only collects the second statement that is run. (OK, that’s not much of a sample, but this is for demonstration purposes. Here is the session definition: CREATE EVENT SESSION counter_test ON SERVERADD EVENT sqlserver.sql_statement_completed    (ACTION (sqlserver.sql_text)    WHERE package0.counter = 2)ADD TARGET package0.ring_bufferWITH (MAX_DISPATCH_LATENCY = 1 SECONDS) You can find general information about the session DDL syntax in BOL and from Pedro’s post Introduction to Extended Events. The important part here is the WHERE statement that defines that I only what the event where package0.count = 2; in other words, only the second instance of the event. Notice that I need to provide the package name along with the predicate source. You don’t need to provide the package name if you’re using event fields, only for predicate sources. Let’s say I run the following test queries: -- Run three statements to test the sessionSELECT 'This is the first statement'GOSELECT 'This is the second statement'GOSELECT 'This is the third statement';GO Once you return the event data from the ring buffer and parse the XML (see my earlier post on reading event data) you should see something like this: event_name sql_text sql_statement_completed SELECT ‘This is the second statement’ You can see that only the second statement from the test was actually collected. (Feel free to try this yourself. Check out what happens if you remove the WHERE statement from your session. Go ahead, I’ll wait.) Percentage Sampling OK, so that wasn’t particularly interesting, but you can probably see that this could be interesting, for example, lets say I need a 25% sample of the statements executed on my server for some type of QA analysis, that might be more interesting than just the second statement. All comparisons of predicates are handled using an object called a predicate comparator; the simple comparisons such as equals, greater than, etc. are mapped to the common mathematical symbols you know and love (eg. = and >), but to do the less common comparisons you will need to use the predicate comparators directly. You would probably look to the MOD operation to do this type sampling; we would too, but we don’t call it MOD, we call it divides_by_uint64. This comparator evaluates whether one number is divisible by another with no remainder. The general syntax for using a predicate comparator is pred_comp(field, value), field is always first and value is always second. So lets take a look at how the session changes to answer our new question of 25% sampling: CREATE EVENT SESSION counter_test_25 ON SERVERADD EVENT sqlserver.sql_statement_completed    (ACTION (sqlserver.sql_text)    WHERE package0.divides_by_uint64(package0.counter,4))ADD TARGET package0.ring_bufferWITH (MAX_DISPATCH_LATENCY = 1 SECONDS)GO Here I’ve replaced the simple equivalency check with the divides_by_uint64 comparator to check if the counter is evenly divisible by 4, which gives us back every fourth record. I’ll leave it as an exercise for the reader to test this session. Why order matters I indicated at the start of this post that order matters when it comes to the counter predicate – it does. Like most other predicate systems, Extended Events evaluates the predicate statement from left to right; as soon as the predicate statement is proven false we abandon evaluation of the remainder of the statement. The counter predicate source is only incremented when it is evaluated so whether or not the counter is incremented will depend on where it is in the predicate statement and whether a previous criteria made the predicate false or not. Here is a generic example: Pred1: (WHERE statement_1 AND package0.counter = 2)Pred2: (WHERE package0.counter = 2 AND statement_1) Let’s say I cause a number of events as follows and examine what happens to the counter predicate source. Iteration Statement Pred1 Counter Pred2 Counter A Not statement_1 0 1 B statement_1 1 2 C Not statement_1 1 3 D statement_1 2 4 As you can see, in the case of Pred1, statement_1 is evaluated first, when it fails (A & C) predicate evaluation is stopped and the counter is not incremented. With Pred2 the counter is evaluated first, so it is incremented on every iteration of the event and the remaining parts of the predicate are then evaluated. In this example, Pred1 would return an event for D while Pred2 would return an event for B. But wait, there is an interesting side-effect here; consider Pred2 if I had run my statements in the following order: Not statement_1 Not statement_1 statement_1 statement_1 In this case I would never get an event back from the system because the point at which counter=2, the rest of the predicate evaluates as false so the event is not returned. If you’re using the counter target for sampling and you’re not getting the expected events, or any events, check the order of the predicate criteria. As a general rule I’d suggest that the counter criteria should be the last element of your predicate statement since that will assure that your sampling rate will apply to the set of event records defined by the rest of your predicate. Aside: I’m interested in hearing about uses for putting the counter predicate criteria earlier in the predicate statement. If you have one, post it in a comment to share with the class. - Mike Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

    Read the article

  • CodePlex Daily Summary for Sunday, March 28, 2010

    CodePlex Daily Summary for Sunday, March 28, 2010New ProjectsFeed Tracker: Feed Tracker allows you to track your favorite feeds (RSS 2.0 and Atom 1.0) and open them up directly in your browser.FIM 2010 Resource Management Client: The Forefront Identity Management 2010 Resource Management Client is a library to communicate with the FIM 2010 web service. The development langu...Infection Protection: A game about controlling disease outbreak in a city. Developed for OGPC 2010, using Qt.OrthoLab: Homepage of Orthocone open-source laboratory.Paragliding ThermalMarker: Paragliding / Hanggliding Windows Application that receives waypoint files and returns only the thermals that get triggered more often in a place.RSSFalls: RssFalls makes it easier for developers to download RSS or Podcast enclosures.String Library for C++ Language: StrLib++ is a string library for C++ language. for now it support only ANSI strings, later Unicode support will added for UT8, UTF16 and UTF32 for...Sweeper: Sweeper is a Visual Studio 2008 add-in for C# that takes care of many of the trivial code-formatting issues that developers run into - particularly...System.Common: A .Net library that provides methods, properties and more that the .Net Framework doesn't provide.Tiveriad: The framework is designed to help you more easily build modular Windows applicationT-Shirts Online: Online shop build in Silverlight 4 using DIBS as payment module.New ReleasesArkSwitch: ArkSwitch v1.1.3: This release has some important changes. Thanks to MichyPrima for helping with some of the code. 1. Improved theming to more easily support multip...Catharsis: Catharsis 2.5 on catarsa.com: The Catharsis framework has finally its own portal http://catarsa.com The latest release version is 2.5 - string names of properties are not any ...EffiProz - A Pure C# Database: EffiProz CF 1.0: EffiProz for .Net compact framework.Encrypted Notes: Encrypted Notes 1.6: This is the latest version of Encrypted Notes (1.6). It has an installer - it will create a directory 'CPascoe' in My Documents. Once you have ext...Extend SmallBasic: Teaching Extensions v.009: Added Pentagon Crazy Recipe QuizGapi.NET - .NET (C#) wrapper for Google API: Gapi.NET 0.5.0.0: - Fixed some minor bugs. - Add minor features. - Performance improvement. See code check-ins for detailed informationHouseFly experimental controls: HouseFly experimental control: Alpha version of HouseFly experimental controlsiTuner - The iTunes Companion: iTuner 1.2.3738 Beta 2: V1.2 allows you to synchronize one or more iTunes playlists to a USB MP3 player. Beta 2 resolves all known issues. This continues the evolution ye...jQuery Library for SharePoint Web Services: SPServices 0.5.4: IMPORTANT NOTE: This release is in an alpha state. You should only download it if you know what you are getting and are interested in testing it f...JSINQ - LINQ to Objects for JavaScript: JSINQ 1.0: This is the first stable release of JSINQ. It is fully compatible with the 0.9 beta release. It contains the following new features: Now supports ...MSBuild Mercurial Tasks: 1.0.0 Beta: First release of the application. This version integrates all the basic functionalities of Mercurial as defined in the Use Case 1.Open Portal Foundation: Open Portal Foundation V1.4.2: What's news? noscript template was updated naming convention for layout autogenerated controls now use the "master" prefix. The documentation ce...Open Portal Foundation: Open Portal Foundation V1.4.4: What's news? ASP .NET Master page support for custom aspx integrated pages New usercontrols for ASCX, ASPX and Master page integration : Link: f...Paint.NET PSD Plugin: 1.5.0: RLE compression is now working fully on save. File sizes are now competitive with Photoshop's. Saving takes about twice as long with RLE compressi...Paragliding ThermalMarker: ThermalMarker_Alfa0.1: Release Alfa 1Simple Service Locator: Simple Service Locator v0.7: The Simple Service Locator is an easy-to-use Inversion of Control library that is a complete implementation of the Common Service Locator interface...String Library for C++ Language: Release 0.9: version 0.9 beta release DO NOT USE IN SERIOUS PROJECTS this release use default application heap, and because visual studio is using special debug...Sweeper: Sweeper Alpha 1: SweeperA Visual Studio Add-in for C# Code Formatting - Visual Studio 2008 Includes: A UI for options, Enable or disable any specific task you want ...T-Shirts Online: 1.0: First release of the online shop.Twilio Server Library for .NET (TSL.NET): v0.1.0 Beta: This is the first release of TSL.NET. This v0.1.0 release is a Beta. Subsequent builds will be posted as v0.1.x and release-candidate Betas will be...Vr30 OS: Facebook 1.0: Connect you to Facebook without your web browser.Vr30 OS: SkyBlog 1.0: SkyBlog without web browser.Vr30 OS: YouTube 1.0: Youtube without web browserWeb Image Resize Handler: Web Image Resize, Zoom, Rotate and Greyscale v.1.0: Efficient Web Image Resize, Zoom, Rotate and Greyscale cacheing handler for ASP.Net.WinXound: WinXound 3.3.0 Beta 1 for Mac OsX: This is the first Beta release for Apple Mac OsX (Universal Binary). DEBUG HELP NEEDED ! Please signal bugs, suggestions or feedback to: stefano_b...Most Popular ProjectsMetaSharpRawrWBFS ManagerASP.NET Ajax LibraryMicrosoft SQL Server Product Samples: DatabaseSilverlight ToolkitAJAX Control ToolkitLiveUpload to FacebookWindows Presentation Foundation (WPF)ASP.NETMost Active ProjectsRawrjQuery Library for SharePoint Web ServicesManaged Extensibility FrameworkBlogEngine.NETMicrosoft Biology Foundationpatterns & practices: Composite WPF and SilverlightLINQ to TwitterFarseer Physics EngineTable2ClassNB_Store - Free DotNetNuke Ecommerce Catalog Module

    Read the article

  • Adding proper THEAD sections to a GridView

    - by Rick Strahl
    I’m working on some legacy code for a customer today and dealing with a page that has my favorite ‘friend’ on it: A GridView control. The ASP.NET GridView control (and also the older DataGrid control) creates some pretty messed up HTML. One of the more annoying things it does is to generate all rows including the header into the page in the <tbody> section of the document rather than in a properly separated <thead> section. Here’s is typical GridView generated HTML output: <table class="tablesorter blackborder" cellspacing="0" rules="all" border="1" id="Table1" style="border-collapse:collapse;"> <tr> <th scope="col">Name</th> <th scope="col">Company</th> <th scope="col">Entered</th><th scope="col">Balance</th> </tr> <tr> <td>Frank Hobson</td><td>Hobson Inc.</td> <td>10/20/2010 12:00:00 AM</td><td>240.00</td> </tr> ... </table> Notice that all content – both the headers and the body of the table – are generated directly under the <table> tag and there’s no explicit use of <tbody> or <thead> (or <tfooter> for that matter). When the browser renders this the document some default settings kick in and the DOM tree turns into something like this: <table> <tbody> <tr> <-- header <tr> <—detail row <tr> <—detail row </tbody> </table> Now if you’re just rendering the Grid server side and you’re applying all your styles through CssClass assignments this isn’t much of a problem. However, if you want to style your grid more generically using hierarchical CSS selectors it gets a lot more tricky to format tables that don’t properly delineate headers and body content. Also many plug-ins and other JavaScript utilities that work on tables require a properly formed table layout, and many of these simple won’t work out of the box with a GridView. For example, one of the things I wanted to do for this app is use the jQuery TableSorter plug-in which – not surprisingly – requires to work of table headers in the DOM document. Out of the box, the TableSorter plug-in doesn’t work with GridView controls, because the lack of a <thead> section to work on. Luckily with a little help of some jQuery scripting there’s a real easy fix to this problem. Basically, if we know the GridView generated table has a header in it, code like the following will move the headers from <tbody> to <thead>: <script type="text/javascript"> $(document).ready(function () { // Fix up GridView to support THEAD tags $("#gvCustomers tbody").before("<thead><tr></tr></thead>"); $("#gvCustomers thead tr").append($("#gvCustomers th")); $("#gvCustomers tbody tr:first").remove(); $("#gvCustomers").tablesorter({ sortList: [[1, 0]] }); }); </script> And voila you have a table that now works with the TableSorter plug-in. If you use GridView’s a lot you might want something a little more generic so the following does the same thing but should work more generically on any GridView/DataGrid missing its <thead> tag: function fixGridView(tableEl) {            var jTbl = $(tableEl);         if(jTbl.find("tbody>tr>th").length > 0) {         jTbl.find("tbody").before("<thead><tr></tr></thead>");         jTbl.find("thead tr").append(jTbl.find("th"));         jTbl.find("tbody tr:first").remove();     } } which you can call like this: $(document).ready(function () { fixGridView( $("#gvCustomers") ); $("#gvCustomers").tablesorter({ sortList: [[1, 0]] }); }); Server Side THEAD Rendering [updated from comments 11/21/2010] Several commenters pointed out that you can also do this on the server side by using the GridView.HeaderRow.TableSection property to force rendering with a proper table header. I was unaware of this option actually – not exactly an easy one to discover. One issue here is that timing of this needs to happen during the databinding process so you need to use an event handler: this.gvCustomers.DataBound += (object o, EventArgs ev) => { gvCustomers.HeaderRow.TableSection = TableRowSection.TableHeader; }; this.gvCustomers.DataSource = custList; this.gvCustomers.DataBind(); You can apply the same logic for the FooterRow. It’s beyond me why this rendering mode isn’t the default for a GridView – why would you ever want to have a table that doesn’t use a THEAD section??? But I disgress :-) I don’t use GridViews much anymore – opting for more flexible approaches using ListViews or even plain code based views or other custom displays that allow more control over layout, but I still see a lot of old code that does use them old clunkers including my own :) (gulp) and this does make life a little bit easier especially if you’re working with any of the jQuery table related plug-ins that expect a proper table structure.© Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET  jQuery  

    Read the article

  • You Say You Want a (Customer Experience) Revolution

    - by Christie Flanagan
    Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} rev-o-lu-tion [rev-uh-loo-shuhn] noun 1. a sudden, radical or complete change 2. fundamental change in the way of thinking about or visualizing something; a change of paradigm 3. a changeover in use or preference especially in technology <the computer revolution> Lately, I've been hearing an awful lot about the customer experience revolution.  Tonight Oracle will be hosting The Experience Revolution, an evening of exploration and networking with customer experience executives in New York City where Oracle President Mark Hurd will introduce Oracle Customer Experience, a cross-stack suite of customer experience products that includes Oracle WebCenter and a number of other Oracle technologies. Then on Tuesday and Wednesday, the Forrester Customer Experience Forum East also kicks off in New York City where they'll examine how businesses can "reap the full business benefits of the customer experience revolution." So, are we in the midst of a customer experience revolution? As a consumer, I can answer that question with a definitive “yes.” When I bought my very first car, I had a lot of questions. How do I know if I’m paying a fair price? How do I know if this dealer is honest? Why do I have to sit through these good cop, bad cop shenanigans between sales and sales management at the dealership? Why do I feel like I’m doing these people a favor by giving them my business? In the end the whole experience left me feeling deeply unsatisfied. I didn’t feel that I held all that much power over the experience and the only real negotiating trick I had was to walk out, which I did, many times before actually making a purchase. Fast forward to a year ago and I found myself back in the market for a new car. The very first car that I bought had finally kicked the bucket after many years, many repair bills, and much wear and tear. Man, I had loved that car. It was time to move on, but I had a knot in my stomach when I reflected back on my last car purchase experience and dreaded the thought of going through that again. Could that have been the reason why I drove my old car for so long? But as I started the process of researching new cars, I started to feel really confident. I had a wealth of online information that helped me in my search. I went to Edmunds and plugged in some information on my preferences and left with a short list of vehicles. After an afternoon spent test driving the cars my short list, I had determined my favorite – it was a model I didn’t even know about until my research on Edmunds! But I didn’t want to go back to the dealership where I test drove it. They were clearly old school and wanted me to buy the way that they wanted to sell. No thanks! After that I went back online. I figured out exactly what people had paid for this car in my area. I found out what kind of discount others were able to negotiate from an online community forum dedicated to the make and model. I found out how the sales people were being incentivized by the manufacturer that month. I learned which dealers had the best ratings and reviews. This was actually getting exciting. I was feeling really empowered. My next step was to request online quotes from the some of the highest rated dealers but I already knew exactly how much I was going to pay. This was really a test for the dealers. My new mantra was “let he who delivers the best customer experience win.” An inside sales rep from one dealer responded to my quote request within a couple of hours. I told him I had already decided on the make and model and it was just a matter of figuring out who I would buy it from. I also told them that I was really busy and wouldn’t set foot in the dealership unless we had come to terms beforehand. Lastly, I let him know that I’d prefer to work out the details via email. He promised to get back to me shortly with a detailed quote. Over the next few days I received calls from other dealers. One asked me a host of questions that I had already answered in their lengthy online form. Another blamed their website performance issues for their delay in responding to my request. But by then it didn’t really matter because I’d already bought the car days before from the dealer who responded to me first and who was willing to adjust their sales process to accommodate my buying one. So, yes, I really do believe we are in the midst of a customer experience revolution. And every revolution leaves some victorious and other vanquished. Which side do you want to be on when it comes to the customer experience revolution?

    Read the article

  • Reg Gets a Job at Red Gate (and what happens behind the scenes)

    - by red(at)work
    Mr Reg Gater works at one of Cambridge’s many high-tech companies. He doesn’t love his job, but he puts up with it because... well, it could be worse. Every day he drives to work around the Red Gate roundabout, wondering what his boss is going to blame him for today, and wondering if there could be a better job out there for him. By late morning he already feels like handing his notice in. He got the hacky look from his boss for being 5 minutes late, and then they ran out of tea. Again. He goes to the local sandwich shop for lunch, and picks up a Red Gate job menu and a Book of Red Gate while he’s waiting for his order. That night, he goes along to Cambridge Geek Nights and sees some very enthusiastic Red Gaters talking about the work they do; it sounds interesting and, of all things, fun. He takes a quick look at the job vacancies on the Red Gate website, and an hour later realises he’s still there – looking at videos, photos and people profiles. He especially likes the Red Gate’s Got Talent page, and is very impressed with Simon Johnson’s marathon time. He thinks that he’d quite like to work with such awesome people. It just so happens that Red Gate recently decided that they wanted to hire another hot shot team member. Behind the scenes, the wheels were set in motion: the recruitment team met with the hiring manager to understand exactly what they’re looking for, and to decide what interview tests to do, who will do the interviews, and to kick-start any interview training those people might need. Next up, a job description and job advert were written, and the job was put on the market. Reg applies, and his CV lands in the Recruitment team’s inbox and they open it up with eager anticipation that Reg could be the next awesome new starter. He looks good, and in a jiffy they’ve arranged an interview. Reg arrives for his interview, and is greeted by a smiley receptionist. She offers him a selection of drinks and he feels instantly relaxed. A couple of interviews and an assessment later, he gets a job offer. We make his day and he makes ours by accepting, and becoming one of the 60 new starters so far this year. Behind the scenes, things start moving all over again. The HR team arranges for a “Welcome” goodie box to be whisked out to him, prepares his contract, sends an email to Information Services (Or IS for short - we’ll come back to them), keeps in touch with Reg to make sure he knows what to expect on his first day, and of course asks him to fill in the all-important wiki questionnaire so his new colleagues can start to get to know him before he even joins. Meanwhile, the IS team see an email in SupportWorks from HR. They see that Reg will be starting in the sales team in a few days’ time, and they know exactly what to do. They pull out a new machine, and within minutes have used their automated deployment software to install every piece of software that a new recruit could ever need. They also check with Reg’s new manager to see if he has any special requirements that they could help with. Reg starts and is amazed to find a fully configured machine sitting on his desk, complete with stationery and all the other tools he’ll need to do his job. He feels even more cared for after he gets a workstation assessment, and realises he’d be comfier with an ergonomic keyboard and a footstool. They arrive minutes later, just like that. His manager starts him off on his induction and sales training. Along with job-specific training, he’ll also have a buddy to help him find his feet, and loads of pre-arranged demos and introductions. Reg settles in nicely, and is great at his job. He enjoys the canteen, and regularly eats one of the 40,000 meals provided each year. He gets used to the selection of teas that are available, develops a taste for champagne launch parties, and has his fair share of the 25,000 cups of coffee downed at Red Gate towers each year. He goes along to some Feel Good Fund events, and donates a little something to charity in exchange for a turn on the chocolate fountain. He’s looking a little scruffy, so he decides to get his hair cut in between meetings, just in time for the Red Gate birthday company photo. Reg starts a new project: identifying existing customers to up-sell to new bundles. He talks with the web team to generate lists of qualifying customers who haven’t recently been sent marketing emails, and sends emails out, using a new in-house developed tool to schedule follow-up calls in CRM for the same group. The customer responds, saying they’d like to upgrade but are having a licensing problem – Reg sends the issue to Support, and it gets routed to the web team. The team identifies a workaround, and the bug gets scheduled into the next maintenance release in a fortnight’s time (hey; they got lucky). With all the new stuff Reg is working on, he realises that he’d be way more efficient if he had a third monitor. He speaks to IS and they get him one - no argument. He also needs a test machine and then some extra memory. Done. He then thinks he needs an iPad, and goes to ask for one. He gets told to stop pushing his luck. Some time later, Reg’s wife has a baby, so Reg gets 2 weeks of paid paternity leave and a bunch of flowers sent to his house. He signs up to the childcare scheme so that he doesn’t have to pay National Insurance on the first £243 of his childcare. The accounts team makes it all happen seamlessly, as they did with his Give As You Earn payments, which come out of his wages and go straight to his favorite charity. Reg’s sales career is going well. He’s grateful for the help that he gets from the product support team. How do they answer all those 900-ish support calls so effortlessly each month? He’s impressed with the patches that are sent out to customers who find “interesting behavior” in their tools, and to the customers who just must have that new feature. A little later in his career at Red Gate, Reg decides that he’d like to learn about management. He goes on some management training specially customised for Red Gate, joins the Management Book Club, and gets together with other new managers to brainstorm how to get the most out of one to one meetings with his team. Reg decides to go for a game of Foosball to celebrate his good fortune with his team, and has to wait for Finance to finish. While he’s waiting, he reflects on the wonderful time he’s had at Red Gate. He can’t put his finger on what it is exactly, but he knows he’s on to a good thing. All of the stuff that happened to Reg didn’t just happen magically. We’ve got teams of people working relentlessly behind the scenes to make sure that everyone here is comfortable, safe, well fed and caffeinated to the max.

    Read the article

  • More Fun with C# Iterators and Generators

    - by James Michael Hare
    In my last post, I talked quite a bit about iterators and how they can be really powerful tools for filtering a list of items down to a subset of items.  This had both pros and cons over returning a full collection, which, in summary, were:   Pros: If traversal is only partial, does not have to visit rest of collection. If evaluation method is costly, only incurs that cost on elements visited. Adds little to no garbage collection pressure.    Cons: Very slight performance impact if you know caller will always consume all items in collection. And as we saw in the last post, that con for the cost was very, very small and only really became evident on very tight loops consuming very large lists completely.    One of the key items to note, though, is the garbage!  In the traditional (return a new collection) method, if you have a 1,000,000 element collection, and wish to transform or filter it in some way, you have to allocate space for that copy of the collection.  That is, say you have a collection of 1,000,000 items and you want to double every item in the collection.  Well, that means you have to allocate a collection to hold those 1,000,000 items to return, which is a lot especially if you are just going to use it once and toss it.   Iterators, though, don't have this problem.  Each time you visit the node, it would return the doubled value of the node (in this example) and not allocate a second collection of 1,000,000 doubled items.  Do you see the distinction?  In both cases, we're consuming 1,000,000 items.  But in one case we pass back each doubled item which is just an int (for example's sake) on the stack and in the other case, we allocate a list containing 1,000,000 items which then must be garbage collected.   So iterators in C# are pretty cool, eh?  Well, here's one more thing a C# iterator can do that a traditional "return a new collection" transformation can't!   It can return **unbounded** collections!   I know, I know, that smells a lot like an infinite loop, eh?  Yes and no.  Basically, you're relying on the caller to put the bounds on the list, and as long as the caller doesn't you keep going.  Consider this example:   public static class Fibonacci {     // returns the infinite fibonacci sequence     public static IEnumerable<int> Sequence()     {         int iteration = 0;         int first = 1;         int second = 1;         int current = 0;         while (true)         {             if (iteration++ < 2)             {                 current = 1;             }             else             {                 current = first + second;                 second = first;                 first = current;             }             yield return current;         }     } }   Whoa, you say!  Yes, that's an infinite loop!  What the heck is going on there?  Yes, that was intentional.  Would it be better to have a fibonacci sequence that returns only a specific number of items?  Perhaps, but that wouldn't give you the power to defer the execution to the caller.   The beauty of this function is it is as infinite as the sequence itself!  The fibonacci sequence is unbounded, and so is this method.  It will continue to return fibonacci numbers for as long as you ask for them.  Now that's not something you can do with a traditional method that would return a collection of ints representing each number.  In that case you would eventually run out of memory as you got to higher and higher numbers.  This method, though, never runs out of memory.   Now, that said, you do have to know when you use it that it is an infinite collection and bound it appropriately.  Fortunately, Linq provides a lot of these extension methods for you!   Let's say you only want the first 10 fibonacci numbers:       foreach(var fib in Fibonacci.Sequence().Take(10))     {         Console.WriteLine(fib);     }   Or let's say you only want the fibonacci numbers that are less than 100:       foreach(var fib in Fibonacci.Sequence().TakeWhile(f => f < 100))     {         Console.WriteLine(fib);     }   So, you see, one of the nice things about iterators is their power to work with virtually any size (even infinite) collections without adding the garbage collection overhead of making new collections.    You can also do fun things like this to make a more "fluent" interface for for loops:   // A set of integer generator extension methods public static class IntExtensions {     // Begins counting to inifity, use To() to range this.     public static IEnumerable<int> Every(this int start)     {         // deliberately avoiding condition because keeps going         // to infinity for as long as values are pulled.         for (var i = start; ; ++i)         {             yield return i;         }     }     // Begins counting to infinity by the given step value, use To() to     public static IEnumerable<int> Every(this int start, int byEvery)     {         // deliberately avoiding condition because keeps going         // to infinity for as long as values are pulled.         for (var i = start; ; i += byEvery)         {             yield return i;         }     }     // Begins counting to inifity, use To() to range this.     public static IEnumerable<int> To(this int start, int end)     {         for (var i = start; i <= end; ++i)         {             yield return i;         }     }     // Ranges the count by specifying the upper range of the count.     public static IEnumerable<int> To(this IEnumerable<int> collection, int end)     {         return collection.TakeWhile(item => item <= end);     } }   Note that there are two versions of each method.  One that starts with an int and one that starts with an IEnumerable<int>.  This is to allow more power in chaining from either an existing collection or from an int.  This lets you do things like:   // count from 1 to 30 foreach(var i in 1.To(30)) {     Console.WriteLine(i); }     // count from 1 to 10 by 2s foreach(var i in 0.Every(2).To(10)) {     Console.WriteLine(i); }     // or, if you want an infinite sequence counting by 5s until something inside breaks you out... foreach(var i in 0.Every(5)) {     if (someCondition)     {         break;     }     ... }     Yes, those are kinda play functions and not particularly useful, but they show some of the power of generators and extension methods to form a fluid interface.   So what do you think?  What are some of your favorite generators and iterators?

    Read the article

  • Single-Signon options for Exchange 2010

    - by freiheit
    We're working on a project to migrate employee email from Unix/open-source (courier IMAP, exim, squirrelmail, etc) to Exchange 2010, and trying to figure out options for single-signon for Outlook Web Access. So far all the options I've found are very ugly and "unsupportable", and may simply not work with Forefront. We already have JA-SIG CAS for token-based single-signon and Shibboleth for SAML. Users are directed to a simple in-house portal (a Perl CGI, really) that they use to sign in to most stuff. We have an HA OpenLDAP cluster that's already synchronized against another AD domain and will be synchronized with the AD domain Exchange will be using. CAS authenticates against LDAP. The portal authenticates against CAS. Shibboleth authenticates with CAS but pulls additional data from LDAP. We're moving in the direction of having web services authenticate against CAS or Shibboleth. (Students are already on SAML/Shibboleth authenticated Google Apps for Education) With Squirrelmail we have a horrible hack linked to from that portal page that authenticates against CAS, gets your original plaintext password (yes, I know, evil), and gives you an HTTP form pre-filled with all the necessary squirrelmail login details with javaScript onLoad stuff to immediately submit the form. Trying to find out exactly what is possible with Exchange/OWA seems to be difficult. "CAS" is both the acronym for our single-signon server and an Exchange component. From what I've been able to tell there's an addon for Exchange that does SAML, but only for federating things like free/busy calendar info, not authenticating users. Plus it costs additional money so there's no way to experiment with it to see if it can be coaxed into doing what we want. Our plans for the Exchange cluster involve Forefront Threat Management Gateway (the new ISA) in the DMZ front-ending the CAS servers. So, the real question: Has anybody managed to make Exchange authenticate with CAS (token-based single-signon) or SAML, or with something I can reasonably likely make authenticate with one of those (such as anything that will accept apache's authentication)? With Forefront? Failing that, anybody have some tips on convincing OWA Forms Based Authentication (FBA) into letting us somehow "pre-login" the user? (log in as them and pass back cookies to the user, or giving the user a pre-filled form that autosubmits like we do with squirrelmail). This is the least-favorite option for a number of reasons, but it would (just barely) satisfy our requirements. From what I hear from the guy implementing Forefront, we may have to set OWA to basic authentication and do forms in Forefront for authentication, so it's possible this isn't even possible. I did find CasOwa, but it only mentions Exchange 2007, looks kinda scary, and as near as I can tell is mostly the same OWA FBA hack I was considering slightly more integrated with the CAS server. It also didn't look like many people had had much success with it. And it may not work with Forefront. There's also "CASifying Outlook Web Access 2", but that one scares me, too, and involves setting up a complex proxy config, which seems more likely to break. And, again, doesn't look like it would work with Forefront. Am I missing something with Exchange SAML (OWA Federated whatchamacallit) where it is possible to configure to do user authentication and not just free/busy access authorization?

    Read the article

  • tile_static, tile_barrier, and tiled matrix multiplication with C++ AMP

    - by Daniel Moth
    We ended the previous post with a mechanical transformation of the C++ AMP matrix multiplication example to the tiled model and in the process introduced tiled_index and tiled_grid. This is part 2. tile_static memory You all know that in regular CPU code, static variables have the same value regardless of which thread accesses the static variable. This is in contrast with non-static local variables, where each thread has its own copy. Back to C++ AMP, the same rules apply and each thread has its own value for local variables in your lambda, whereas all threads see the same global memory, which is the data they have access to via the array and array_view. In addition, on an accelerator like the GPU, there is a programmable cache, a third kind of memory type if you'd like to think of it that way (some call it shared memory, others call it scratchpad memory). Variables stored in that memory share the same value for every thread in the same tile. So, when you use the tiled model, you can have variables where each thread in the same tile sees the same value for that variable, that threads from other tiles do not. The new storage class for local variables introduced for this purpose is called tile_static. You can only use tile_static in restrict(direct3d) functions, and only when explicitly using the tiled model. What this looks like in code should be no surprise, but here is a snippet to confirm your mental image, using a good old regular C array // each tile of threads has its own copy of locA, // shared among the threads of the tile tile_static float locA[16][16]; Note that tile_static variables are scoped and have the lifetime of the tile, and they cannot have constructors or destructors. tile_barrier In amp.h one of the types introduced is tile_barrier. You cannot construct this object yourself (although if you had one, you could use a copy constructor to create another one). So how do you get one of these? You get it, from a tiled_index object. Beyond the 4 properties returning index objects, tiled_index has another property, barrier, that returns a tile_barrier object. The tile_barrier class exposes a single member, the method wait. 15: // Given a tiled_index object named t_idx 16: t_idx.barrier.wait(); 17: // more code …in the code above, all threads in the tile will reach line 16 before a single one progresses to line 17. Note that all threads must be able to reach the barrier, i.e. if you had branchy code in such a way which meant that there is a chance that not all threads could reach line 16, then the code above would be illegal. Tiled Matrix Multiplication Example – part 2 So now that we added to our understanding the concepts of tile_static and tile_barrier, let me obfuscate rewrite the matrix multiplication code so that it takes advantage of tiling. Before you start reading this, I suggest you get a cup of your favorite non-alcoholic beverage to enjoy while you try to fully understand the code. 01: void MatrixMultiplyTiled(vector<float>& vC, const vector<float>& vA, const vector<float>& vB, int M, int N, int W) 02: { 03: static const int TS = 16; 04: array_view<const float,2> a(M, W, vA); 05: array_view<const float,2> b(W, N, vB); 06: array_view<writeonly<float>,2> c(M,N,vC); 07: parallel_for_each(c.grid.tile< TS, TS >(), 08: [=] (tiled_index< TS, TS> t_idx) restrict(direct3d) 09: { 10: int row = t_idx.local[0]; int col = t_idx.local[1]; 11: float sum = 0.0f; 12: for (int i = 0; i < W; i += TS) { 13: tile_static float locA[TS][TS], locB[TS][TS]; 14: locA[row][col] = a(t_idx.global[0], col + i); 15: locB[row][col] = b(row + i, t_idx.global[1]); 16: t_idx.barrier.wait(); 17: for (int k = 0; k < TS; k++) 18: sum += locA[row][k] * locB[k][col]; 19: t_idx.barrier.wait(); 20: } 21: c[t_idx.global] = sum; 22: }); 23: } Notice that all the code up to line 9 is the same as per the changes we made in part 1 of tiling introduction. If you squint, the body of the lambda itself preserves the original algorithm on lines 10, 11, and 17, 18, and 21. The difference being that those lines use new indexing and the tile_static arrays; the tile_static arrays are declared and initialized on the brand new lines 13-15. On those lines we copy from the global memory represented by the array_view objects (a and b), to the tile_static vanilla arrays (locA and locB) – we are copying enough to fit a tile. Because in the code that follows on line 18 we expect the data for this tile to be in the tile_static storage, we need to synchronize the threads within each tile with a barrier, which we do on line 16 (to avoid accessing uninitialized memory on line 18). We also need to synchronize the threads within a tile on line 19, again to avoid the race between lines 14, 15 (retrieving the next set of data for each tile and overwriting the previous set) and line 18 (not being done processing the previous set of data). Luckily, as part of the awesome C++ AMP debugger in Visual Studio there is an option that helps you find such races, but that is a story for another blog post another time. May I suggest reading the next section, and then coming back to re-read and walk through this code with pen and paper to really grok what is going on, if you haven't already? Cool. Why would I introduce this tiling complexity into my code? Funny you should ask that, I was just about to tell you. There is only one reason we tiled our extent, had to deal with finding a good tile size, ensure the number of threads we schedule are correctly divisible with the tile size, had to use a tiled_index instead of a normal index, and had to understand tile_barrier and to figure out where we need to use it, and double the size of our lambda in terms of lines of code: the reason is to be able to use tile_static memory. Why do we want to use tile_static memory? Because accessing tile_static memory is around 10 times faster than accessing the global memory on an accelerator like the GPU, e.g. in the code above, if you can get 150GB/second accessing data from the array_view a, you can get 1500GB/second accessing the tile_static array locA. And since by definition you are dealing with really large data sets, the savings really pay off. We have seen tiled implementations being twice as fast as their non-tiled counterparts. Now, some algorithms will not have performance benefits from tiling (and in fact may deteriorate), e.g. algorithms that require you to go only once to global memory will not benefit from tiling, since with tiling you already have to fetch the data once from global memory! Other algorithms may benefit, but you may decide that you are happy with your code being 150 times faster than the serial-version you had, and you do not need to invest to make it 250 times faster. Also algorithms with more than 3 dimensions, which C++ AMP supports in the non-tiled model, cannot be tiled. Also note that in future releases, we may invest in making the non-tiled model, which already uses tiling under the covers, go the extra step and use tile_static memory on your behalf, but it is obviously way to early to commit to anything like that, and we certainly don't do any of that today. Comments about this post by Daniel Moth welcome at the original blog.

    Read the article

  • Full-text Indexing Books Online

    - by Most Valuable Yak (Rob Volk)
    While preparing for a recent SQL Saturday presentation, I was struck by a crazy idea (shocking, I know): Could someone import the content of SQL Server Books Online into a database and apply full-text indexing to it?  The answer is yes, and it's really quite easy to do. The first step is finding the installed help files.  If you have SQL Server 2012, BOL is installed under the Microsoft Help Library.  You can find the install location by opening SQL Server Books Online and clicking the gear icon for the Help Library Manager.  When the new window pops up click the Settings link, you'll get the following: You'll see the path under Library Location. Once you navigate to that path you'll have to drill down a little further, to C:\ProgramData\Microsoft\HelpLibrary\content\Microsoft\store.  This is where the help file content is kept if you downloaded it for offline use. Depending on which products you've downloaded help for, you may see a few hundred files.  Fortunately they're named well and you can easily find the "SQL_Server_Denali_Books_Online_" files.  We are interested in the .MSHC files only, and can skip the Installation and Developer Reference files. Despite the .MHSC extension, these files are compressed with the standard Zip format, so your favorite archive utility (WinZip, 7Zip, WinRar, etc.) can open them.  When you do, you'll see a few thousand files in the archive.  We are only interested in the .htm files, but there's no harm in extracting all of them to a folder.  7zip provides a command-line utility and the following will extract to a D:\SQLHelp folder previously created: 7z e –oD:\SQLHelp "C:\ProgramData\Microsoft\HelpLibrary\content\Microsoft\store\SQL_Server_Denali_Books_Online_B780_SQL_110_en-us_1.2.mshc" *.htm Well that's great Rob, but how do I put all those files into a full-text index? I'll tell you in a second, but first we have to set up a few things on the database side.  I'll be using a database named Explore (you can certainly change that) and the following setup is a fragment of the script I used in my presentation: USE Explore; GO CREATE SCHEMA help AUTHORIZATION dbo; GO -- Create default fulltext catalog for later FT indexes CREATE FULLTEXT CATALOG FTC AS DEFAULT; GO CREATE TABLE help.files(file_id int not null IDENTITY(1,1) CONSTRAINT PK_help_files PRIMARY KEY, path varchar(256) not null CONSTRAINT UNQ_help_files_path UNIQUE, doc_type varchar(6) DEFAULT('.xml'), content varbinary(max) not null); CREATE FULLTEXT INDEX ON help.files(content TYPE COLUMN doc_type LANGUAGE 1033) KEY INDEX PK_help_files; This will give you a table, default full-text catalog, and full-text index on that table for the content you're going to insert.  I'll be using the command line again for this, it's the easiest method I know: for %a in (D:\SQLHelp\*.htm) do sqlcmd -S. -E -d Explore -Q"set nocount on;insert help.files(path,content) select '%a', cast(c as varbinary(max)) from openrowset(bulk '%a', SINGLE_CLOB) as c(c)" You'll need to copy and run that as one line in a command prompt.  I'll explain what this does while you run it and watch several thousand files get imported: The "for" command allows you to loop over a collection of items.  In this case we want all the .htm files in the D:\SQLHelp folder.  For each file it finds, it will assign the full path and file name to the %a variable.  In the "do" clause, we'll specify another command to be run for each iteration of the loop.  I make a call to "sqlcmd" in order to run a SQL statement.  I pass in the name of the server (-S.), where "." represents the local default instance. I specify -d Explore as the database, and -E for trusted connection.  I then use -Q to run a query that I enclose in double quotes. The query uses OPENROWSET(BULK…SINGLE_CLOB) to open the file as a data source, and to treat it as a single character large object.  In order for full-text indexing to work properly, I have to convert the text content to varbinary. I then INSERT these contents along with the full path of the file into the help.files table created earlier.  This process continues for each file in the folder, creating one new row in the table. And that's it! 5 SQL Statements and 2 command line statements to unzip and import SQL Server Books Online!  In case you're wondering why I didn't use FILESTREAM or FILETABLE, it's simply because I haven't learned them…yet. I may return to this blog after I figure that out and update it with the steps to do so.  I believe that will make it even easier. In the spirit of exploration, I'll leave you to work on some fulltext queries of this content.  I also recommend playing around with the sys.dm_fts_xxxx DMVs (I particularly like sys.dm_fts_index_keywords, it's pretty interesting).  There are additional example queries in the download material for my presentation linked above. Many thanks to Kevin Boles (t) for his advice on (re)checking the content of the help files.  Don't let that .htm extension fool you! The 2012 help files are actually XML, and you'd need to specify '.xml' in your document type column in order to extract the full-text keywords.  (You probably noticed this in the default definition for the doc_type column.)  You can query sys.fulltext_document_types to get a complete list of the types that can be full-text indexed. I also need to thank Hilary Cotter for giving me the original idea. I believe he used MSDN content in a full-text index for an article from waaaaaaaaaaay back, that I can't find now, and had forgotten about until just a few days ago.  He is also co-author of Pro Full-Text Search in SQL Server 2008, which I highly recommend.  He also has some FTS articles on Simple Talk: http://www.simple-talk.com/sql/learn-sql-server/sql-server-full-text-search-language-features/ http://www.simple-talk.com/sql/learn-sql-server/sql-server-full-text-search-language-features,-part-2/

    Read the article

  • Looking into the JQuery Image Zoom Plugin

    - by nikolaosk
    I have been using JQuery for a couple of years now and it has helped me to solve many problems on the client side of web development.  You can find all my posts about JQuery in this link. In this post I will be providing you with a hands-on example on the JQuery Image Zoom Plugin.If you want you can have a look at this post, where I describe the JQuery Cycle Plugin.You can find another post of mine talking about the JQuery Carousel Lite Plugin here.I will be writing more posts regarding the most commonly used JQuery Plugins. I have been using extensively this plugin in my websites.You can use this plugin to move mouse around an image and see a zoomed in version of a portion of it. In this hands-on example I will be using Expression Web 4.0.This application is not a free application. You can use any HTML editor you like. You can use Visual Studio 2012 Express edition. You can download it here.  You can download this plugin from this link I launch Expression Web 4.0 and then I type the following HTML markup (I am using HTML 5) <html lang="en">  <head>    <title>Liverpool Legends</title>        <meta http-equiv="Content-Type" content="text/html;charset=utf-8" >        <link rel="stylesheet" type="text/css" href="style.css">        <script type="text/javascript" src="jquery-1.8.3.min.js"> </script>     <script type="text/javascript" src="jqzoom.pack.1.0.1.js"></script>        <script type="text/javascript">        $(function () {            $(".nicezoom").jqzoom();        });    </script>       </head>  <body>    <header>        <h1>Liverpool Legends</h1>    </header>        <div id="main">            <a href="championsofeurope-large.jpg" class="nicezoom" title="Champions">        <img src="championsofeurope.jpg"  title="Champions">    </a>          </div>            <footer>        <p>All Rights Reserved</p>      </footer>     </body>  </html>   This is a very simple markup. I have added one large and one small image (make sure you use your own when trying this example) I have added references to the JQuery library (current version is 1.8.3) and the JQuery Image Zoom Plugin. Then I add 2 images in the main div element.Note the class nicezoom inside the href element. The Javascript code that makes it all happen follows.    <script type="text/javascript">        $(function () {            $(".nicezoom").jqzoom();        });    </script>     It couldn't be any simpler than that. I view my simple in Internet Explorer 10 and it works as expected. I have tested this simple solution in all major browsers and it works fine.Inside the head section we can add another Javascript script utilising some more options regarding the zoom plugin.   <script type="text/javascript">            $(function () {        var options = {                  zoomType: 'standard',                  lens:true,                  preloadImages: true,                  alwaysOn:false,                  zoomWidth: 400,                  zoomHeight: 350,                  xOffset:190,                  yOffset:80,                  position:'right'                          };          $('.nicezoom').jqzoom(options);      });         </script> I would like to explain briefly what some of those options mean. zoomType - Other admitted option values are 'reverse','drag','innerzoom' zoomWidth - The popup window width showing the zoomed area zoomHeight - The popup window height showing the zoomed area xOffset - The popup window x offset from the small image.  yOffset - The popup window y offset from the small image.  position - The popup window position.Admitted values:'right' ,'left' ,'top' ,'bottom' preloadImages - if set to true,jqzoom will preload large images. You can test it yourself and see the results in your favorite browser. Hope it helps!!!

    Read the article

  • Where should I go with hosting my site: VPS, GAE, another option?

    - by Jonathan Hayward
    My website, http://JonathansCorner.com/, began life before 1994 as www.imsa.edu/~jhayward/ and has been through various iterations and improvements to content, HTML, and the like, but remains a literature site that is from a web administrator's perspective fairly simple and primitive: a fair amount of static HTML and supporting files, a little bit of CGI and URI rewriting, .htaccess files providing Expires: headers and the like. An associated site demoes various CGI scripts that fall under the category of "and other creations"; the site as a whole has the purpose of sharing my creative works, and so far a fairly rudimentary use of Apache functionality, supported by Unix tools to, for instance, update RSS feed and the "starting point" link on the home page, has served that purpose fairly well. I looked around here on web hosting, and found the note on web host reccommendations as a good note for "What are some of people's favorite web hosts overall," but I wanted to ask a more focused question of "What are the best web hosts for criteria XYZ:" I am looking at a VPS so I will have root, be able to install stuff and edit Apache's config files etc., running Gentoo or other Linux, BSD, or the like. I would like a system that is secure enough that the host's vulnerabilities are mostly the ones that come along with what I am trying to do: that is, I won't be trying to administer and secure an ancient Linux like some have complained about at 1and1. I would like good uptime/reliability and competent support staff: if the level 1 help desk is going to tell me to go to "My Computer" on a Linux box, I'd like to be able to get past them. Ideally I would like a site hosted within some place that will have low latency for U.S. visitors in particular. I would like a hosting solution that will be with a stable business, one that will probably be around, and one unlikely to vanish without warning. With those things specified, I would be interested in knowing what are the less expensive options. (I expect that some of the things I've specified will knock out all of the cheapest options, but I'm still interested in price.) With all that stated, I'd like to back up a bit and look at whether I am asking the right question. I am concerned that the above is a very good way of asking, "How can I keep my site in line with the wave of the past?" I am wondering if it might be specifically wiser to look to adapt my site to newer technologies instead of trying to keep it on older technologies. For instance, while I would hardly portray my site as a way to show off the full power of Google App Engine, the main site at least should be a straightforward port if I were to do that. And beyond Google App Engine, my knowledge of cloud solutions is basic. If it is a better and more future-proof solution to port my site to another kind of solution, I would be interested in knowing where those future-proof solutions lie. So I would be interested in wisdom. If the question I asked in detail is still a good question to be asking, what would people suggest? Or if I should seriously consider porting my site to a newer basic option, what should I try there? Any thoughts would be appreciated.

    Read the article

  • Spacewalk 2.0 provided to manage Oracle Linux systems

    - by wcoekaer
    Oracle Linux customers have a few options to manage and provision their servers. We provide a license to use Oracle Enterprise Manager's Linux OS management, monitoring and provisioning features without additional cost for every server that has an Oracle Linux support subscription. So there is no additional pack to license and no additional per server cost, it's all included in our Basic, Premier and Systems support subscriptions. The nice thing with Oracle Enterprise Manager is that you end up with a single management product that can manage all aspects of your software stack. You have complete insight into the applications running, you have roles and responsibilities, you have third party connectors for storage or other products and it makes it very easy and convenient to correlate data and events when something happens. If you use Oracle VM as well, you end up with a complete cloud portal with selfservice, chargeback, etc... Another, much simpler option, is just using yum. It is very easy to take a server and create directories and expose these through apache as repositories. You can have a simple yum config on each server pointing to a few specific repositories. It requires some manual effort in terms of creating directories, downloading packages and creating local repo files but it's easy to do and for many people a preferred solution. There are also a good number of customers that just connect their servers directly to ULN or to our free update server public-yum. Just to re-iterate, our public-yum servers have all the errata and updates available for free. Now we added another option. Many of our customers have switched from a competing Linux vendor and they had familiarity with their management tools. Switching to Oracle for support is very easy since we don't require changes to the installed servers but we also want to make sure there is a very easy and almost transparent switch for the management tools as well. While Oracle Enterprise Manager is our preferred way of managing systems, we now are offering Spacewalk 2.0 to our customers. The community project can be found here. We have made a few changes to ensure easy and complete support for Oracle Linux, tested it with public-yum, etc.. You can find the rpms in our public-yum repos at http://public-yum.oracle.com/repo/OracleLinux/OL6/. There are repositories for spacewalk server and then for each version (OL5,OL6) and architecture (x86 and x86-64) we have the client repositories as well. Spacewalk itself is only made available for OL6 x86-64. Documentation can be found here. I set it up myself and here are some quick steps on how you can get going in just a matter of minutes: Spacewalk Server Installation : 1) Installing an Oracle Database Use an existing Oracle Database or install a new Oracle Database (Standard or Enterprise Edition) [at this time use 11g, we will add support for 12c in the near future]. This database can be installed on the spacewalk server or on a separate remote server. While Oracle XE might work to create a small sample POC, we do not support the use of Oracle XE, spacewalk repositories can become large and create a significant database workload. Customers can use their existing database licenses, they can download the database with a trial licence from http://edelivery.oracle.com or Oracle Linux subscribers (customers) will be allowed to use the Oracle Database as a spacewalk repository as part of their Oracle Linux subscription at no additional cost. |NOTE : spacewalk requires the database to be configured with the UTF8 characterset. |Installation will fail if your database does not use UTF8. |To verify if your database is configured correctly, run the following command in sqlplus: | |select value from nls_database_parameters where parameter='NLS_CHARACTERSET'; |This should return 'AL32UTF8' 2) Configure the database schema for spacewalk Ideally, create a tablespace in the database to hold the spacewalk schema tables/data; create tablespace spacewalk datafile '/u01/app/oracle/oradata/orcl/spacewalk.dbf' size 10G autoextend on; Create the database user spacewalk (or use some other schema name) in sqlplus. example : create user spacewalk identified by spacewalk; grant connect, resource to spacewalk; grant create table, create trigger, create synonym, create view, alter session to spacewalk; grant unlimited tablespace to spacewalk; alter user spacewalk default tablespace spacewalk; 4) Spacewalk installation and configuration Spacewalk server requires an Oracle Linux 6 x86-64 system. Clients can be Oracle Linux 5 or 6, both 32- and 64bit. The server is only supported on OL6/64bit. The easiest way to get started is to do a 'Minimal' install of Oracle Linux on a server and configure the yum repository to include the spacewalk repo from public-yum. Once you have a system with a minimal install, modify your yum repo to include the spacewalk repo. Example : edit /etc/yum.repos.d/public-yum-ol.repo and add the following lines at the end of the file : [spacewalk] name=spacewalk baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL6/spacewalk20/server/$basearch/ gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 gpgcheck=1 enabled=1 Install the following pre-requisite packages on your spacewalk server : oracle-instantclient11.2-basic-11.2.0.3.0-1.x86_64 oracle-instantclient11.2-sqlplus-11.2.0.3.0-1.x86_64 rpm -ivh oracle-instantclient11.2-basic-11.2.0.3.0-1.x86_64 rpm -ivh oracle-instantclient11.2-sqlplus-11.2.0.3.0-1.x86_64 The above RPMs can be found on the Oracle Technology Network website : http://www.oracle.com/technetwork/topics/linuxx86-64soft-092277.html As the root user, configure the library path to include the Oracle Instant Client libraries : cd /etc/ld.so.conf.d echo /usr/lib/oracle/11.2/client64/lib oracle-instantclient11.2.conf ldconfig Install spacewalk : # yum install spacewalk-oracle The above yum command should download and install all required packages to run spacewalk on your local server. | NOTE : if you did a full, desktop or workstation installation, | you have to remove the JTA package | BEFORE installing spacewalk-oracle (rpm -e --nodeps jta) Once the installation completes, simply run the spacewalk configuration tool and you are all set. (make sure to run the command with the 2 arguments) spacewalk-setup --disconnected --external-db Answer the questions during the setup, ensure you provide the current database user (example : spacewalk) and password (example : spacewalk) and database server hostname (the standard hostname of the server on which you have deployed the Oracle database) At the end of the setup script, your spacewalk server should be fully configured and you can log into the web portal. Use your favorite browser to connect to the website : http://[spacewalkserverhostname] The very first action will be to create the main admin account.

    Read the article

  • Securing WebSocket applications on Glassfish

    - by Pavel Bucek
    Today we are going to cover deploying secured WebSocket applications on Glassfish and access to these services using WebSocket Client API. WebSocket server application setup Our server endpoint might look as simple as this: @ServerEndpoint("/echo") public class EchoEndpoint { @OnMessage   public String echo(String message) {     return message + " (from your server)";   } } Everything else must be configured on container level. We can start with enabling SSL, which will require web.xml to be added to your project. For starters, it might look as following: <web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee">   <security-constraint>     <web-resource-collection>       <web-resource-name>Protected resource</web-resource-name>       <url-pattern>/*</url-pattern>       <http-method>GET</http-method>     </web-resource-collection>     <!-- https -->     <user-data-constraint>       <transport-guarantee>CONFIDENTIAL</transport-guarantee>     </user-data-constraint>   </security-constraint> </web-app> This is minimal web.xml for this task - web-resource-collection just defines URL pattern and HTTP method(s) we want to put a constraint on and user-data-constraint defines that constraint, which is in our case transport-guarantee. More information about these properties and security settings for web application can be found in Oracle Java EE 7 Tutorial. I have some simple webpage attached as well, so I can test my endpoint right away. You can find it (along with complete project) in Tyrus workspace: [webpage] [whole project]. After deploying this application to Glassfish Application Server, you should be able to hit it using your favorite browser. URL where my application resides is https://localhost:8181/sample-echo-https/ (may be different, depends on other configuration). My browser warns me about untrusted certificate (I use what freshly built Glassfish provides - self signed certificates) and after adding an exception for this site, I can see my webpage and I am able to securely connect to wss://localhost:8181/sample-echo-https/echo. WebSocket client Already mentioned demo application also contains test client, but execution of this is skipped for normal build. Reason for this is that Glassfish uses these self-signed "random" untrusted certificates and you are (in most cases) not able to connect to these services without any additional settings. Creating test WebSocket client is actually quite similar to server side, only difference is that you have to somewhere create client container and invoke connect with some additional info. Java API for WebSocket allows you to use annotated and programmatic way to construct endpoints. Server side shows the annotated case, so let's see how the programmatic approach will look. final WebSocketContainer client = ContainerProvider.getWebSocketContainer(); client.connectToServer(new Endpoint() {   @Override   public void onOpen(Session session, EndpointConfig EndpointConfig) {     try {       // register message handler - will just print out the       // received message on standard output.       session.addMessageHandler(new MessageHandler.Whole<String>() {       @Override         public void onMessage(String message) {          System.out.println("### Received: " + message);         }       });       // send a message       session.getBasicRemote().sendText("Do or do not, there is no try.");     } catch (IOException e) {       // do nothing     }   } }, ClientEndpointConfig.Builder.create().build(),    URI.create("wss://localhost:8181/sample-echo-https/echo")); This client should work with some secured endpoint with valid certificated signed by some trusted certificate authority (you can try that with wss://echo.websocket.org). Accessing our Glassfish instance will require some additional settings. You can tell Java which certificated you trust by adding -Djavax.net.ssl.trustStore property (and few others in case you are using linked sample). Complete command line when you are testing your service might need to look somewhat like: mvn clean test -Djavax.net.ssl.trustStore=$AS_MAIN/domains/domain1/config/cacerts.jks\ -Djavax.net.ssl.trustStorePassword=changeit -Dtyrus.test.host=localhost\ -DskipTests=false Where AS_MAIN points to your Glassfish instance. Note: you might need to setup keyStore and trustStore per client instead of per JVM; there is a way how to do it, but it is Tyrus proprietary feature: http://tyrus.java.net/documentation/1.2.1/user-guide.html#d0e1128. And that's it! Now nobody is able to "hear" what you are sending to or receiving from your WebSocket endpoint. There is always room for improvement, so the next step you might want to take is introduce some authentication mechanism (like HTTP Basic or Digest). This topic is more about container configuration so I'm not going to go into details, but there is one thing worth mentioning: to access services which require authorization, you might need to put this additional information to HTTP headers of first (Upgrade) request (there is not (yet) any direct support even for these fundamental mechanisms, user need to register Configurator and add headers in beforeRequest method invocation). I filed related feature request as TYRUS-228; feel free to comment/vote if you need this functionality.

    Read the article

  • Top 10 Browser Productivity Tips

    - by Renso
    Originally posted on: http://geekswithblogs.net/renso/archive/2013/10/14/top-10-browser-productivity-tips.aspxYou don’t have to be a geek to be a productive browser user. The tips below have been selected by actions users take most of the time to navigate a web-site but use long-standing keyboard or mouse actions to get them done, when there are keyboard short-cuts you can use instead. Since you hands are already on the keyboard it is almost always faster to sue a keyboard shortcut to get something done that you usually used the mouse for. For example right-clicking on something to copy it and then doing to same for pasting something is very time consuming, keyboard shortcuts have been created that simplify the task. All it takes are a few memory brain cells to remember them. Here are the tips, in no particular order:   Tip 1 Hold down the spacebar on your keyboard to page to the end of your web page rather than using your mouse. This is really a slow way of doing it. If you want to page one page at a time, hit the spacebar once, and again to page again. But if you want to page all the way to the end of the web page simply hit Ctrl+End (that is hold down the Ctrl key and hit the End button on your keyboard). To get to the top of your web page, simply hit Ctrl + Home to go all the way to the top of your web page. Tip 2 Where are my downloads? Some folks run downloads again-and-again because they do not know where the last one went and they do not see the popup, or browser note on their web page in the footer, etc. Simply hit Ctrl+J. Works in most browsers. Tip 3 Selecting a US state from a drop down box. Don’t use the mouse, takes just way too long to scroll. When you tab to the drop down box or click on it with your mouse, simply hit the first character of the state and it will be selected. For Texas for example hit the letter “T” twice on your keyboard to get to it. The same concept can be applied to any drop down box that is alphabetical or numerically sorted. Tip 4 Fixing spelling errors. All modern-day browsers support this now. You see the red wavy lines underscoring a word, yes it is a spelling error. How do you fix it? Don’t overtype it or try and fix it manually, fist right-click on it and a list of suggestions comes up. If it does not show up, like my name “Renso” and you know how to spell your name as in this example, look further down the list of options (the little window popup that appears when you right click) and you should see an option to “Add to Dictionary”. Be warned, when you add it, it only adds it to the browser you’re using’s dictionary. If you use Google Chrome, Firefox and IE, each one will have their own list. Tip 5 So you have trouble seeing the text on the screen. Or you are looking at a photo, for example in Facebook. You want to zoom in to read better or zoom into a photo a bit more. Hit Ctrl++ (hold down Ctrl key and hit the plus key – actually it’s the equal key but it is easier to remember that it is plus for bigger). Hit the minus to zoom out. Now you can’t remember what the original size was since you were so excited to hit it 20 times, or was that 21… Simply hit Ctrl+0 (that is zero) and it will reset it to the default. Tip 6 So you closed a couple of tabs in your browser. Suddenly you remember something you wanted to double-check something on one of the tabs, you cannot remember the URL ad the tab is gone forever, or is it? Simply hit Ctrl+Shift+t and it will bring back your tabs one by one each time you click the T. This has also been a great way for me to quickly close some tabs because I don’t want my boss to see I’m shopping and then hitting Ctrl+Shift+t to quickly get it back and complete my check-put and purchase. Or, for parents, when you walk into your daughter’s room and you see she quickly clicks and closes a window/tab in here browser. Not to worry my little darling, daddy will Ctrl+Shift+t and see what boys on Facebook you were talking too… Tip 7 The web browser is frozen on your PC/Laptop/Whatever, in this example it may be your Internet Explorer browser. I don’t mention Firefox or Chrome here because it probably never happens in their world. You cannot close it, it won’t respond to anything you have done s far except for the next step you are about to take, which is throw your two-day old coffee on your keyboard. This happens especially on sites that want to force you to complete a purchase order. Hit Ctrl+Alt+Del on your keyboard on any version of windows, select TASK MANAGER. In the  First Tab, which is the Process Tab, look for the item in question. In this example you should see Internet Explorer. Right-click it and select “End Task”. It will force the thread out of memory and terminate that process. You can of course do this with any program running under your account. Tip 8 This is a personal favorite of mine. To select words in the paragraph without using the mouse. You don’t want to select one character at a time like when you use the Ctrl+arrows as it can be very slow if you want to select a lot of text. You also want to select whole words. Simply use the Ctrl+Shift_arrow (right or left depending which direction you want to go. Tip 9 I was a bit reluctant to add this one, but being in the professional services industry still come across many-a-folk that simply can’t copy-and-paste them-all text or images that reside on them screens, y’all. Ctrl+c to copy and Ctrl+v to paste it. Works a lot faster than using the mouse. You may be asking: “Well why in the devil did they not use Ctrl+p for paste…. because that is for printing. This is of course not limited to the browser world, it applies to almost any piece of software running on PC or Mac. Go try it on an image on your browser, right-click it and select copy. Open a word document and Ctrl+v to paste the image in there. Please consider copyright laws. Tip 10 Getting rid of annoying ads. Now this only works when you load a web page, meaning when you get back to the same page later you will have to do this again and you will need to learn a tool to do it, WELL WORTH IT. For example, I use GrooveShark to listen to music but I don’t like the ads they show. Install a tool like Firebug for Firefox or use the Ctrl+Shift+I on Chrome to bring up the developer toolbar. Shows at the bottom of the page. With Firefox, once you have installed Firebug as an add-on, a yellow bug should appear on the top right-hand-side of your browser, click on it to display the developer toolbar. You will need to learn how to use it, but once you know how to select an item/section on the window (usually just right-click the add you don’t want to see and select “Inspect Element”, the developer toolbar will appear (if not already there)) and then simply hit delete and it will remove the add from the screen. If you don’t know HTML you may need to play with it a bit, but once you understand how it works can open up a whole new world for you on how web pages actually work. If you can think of any others that have saved you a ton of time please let me know so I can add them to a top 99 list.

    Read the article

  • Reviewing Retail Predictions for 2011

    - by David Dorf
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} I've been busy thinking about what 2012 and beyond will look like for retail, and I have some interesting predictions to share.  But before I go there, let’s first review this year’s predictions before making new ones for 2012. 1. Alternate Payments We've seen several alternate payment schemes emerge over the last two years, and 2011 may be the year one of them takes hold. Any competition that can drive down fees will be good for everyone. I'm betting that Apple will add NFC chips to their next version of the iPhone, then enable payments in stores using iTunes accounts on the backend. Paypal will continue to make inroads, and Isis will announce a pilot. The iPhone 4S did not contain an NFC chip, so we’ll have to continuing waiting for the iPhone 5. PayPal announced its moving into in-store payments, and Google launched its wallet in selected cities.  Overall I think the payment scene is heating up and that trend will continue. 2. Engineered Systems The industry is moving toward purpose-built appliances that are optimized across the entire stack. Oracle calls these "engineered systems" and the first two examples are Exadata and Exalogic, but there are other examples from other vendors. These are particularly important to the retail industry because of the volume of data that must be processed. There should be continued adoption in 2011. Oracle reports that Exadata is its fasting growing product, and at the recent OpenWorld it announced the SuperCluster and Exalytics products, both continuing the engineered systems trend. SAP’s HANA continues to receive attention, and IBM also seems to be moving in this direction. 3. Social Analytics There are lots of tools that provide insight into how a brand is perceived across popular internet sites, but as far as I know, these tools are not industry specific. The next step needs to mine the data and determine how it should influence retail operations. The data needs to help retailers determine how they create promotions, which products to stock, and how to keep consumers engaged. Social data alone does not provide the answers, but its one more data point that will help retailers make better decisions. Look for some vendor consolidation to help make this happen. In March, Salesforce.com acquired leading social monitoring vendor Radian6 and followed up with acquisitions of Heroku and Model Metrics. The notion of Social CRM seems to be going more mainstream now. 4. 2-D Barcodes Look for more QRCodes on shelf-tags, in newspaper circulars, and on billboards. It's a great portal from the physical world into the digital one that buys us time until augmented reality matures further. Nobody wants to type "www", backslash, and ".com" on their phones. QRCodes are everywhere. ‘Nuff said. 5. In the words of Microsoft, "To the Cloud!" My favorite "cloud application" is Evernote. If you take notes on your work laptop, you will inevitably need those notes on your home PC. And if you manage to solve that problem, you'll need to access them from your mobile phone. Evernote stores your notes in the cloud and provides easy ways to access them. Being able to access a service from anywhere and not having to worry about backups, upgrades, etc. is great. Retailers will start to rely on cloud services, both public and private, in the coming year. There were no shortage of announcements in this area: Amazon’s cloud-based Kindle Fire, Apple’s iCloud, Oracle’s Public Cloud, etc. I saw an interesting presentation showing how BevMo moved their systems to the cloud.  Seems like retailers are starting to consider the cloud for specific uses. 6. F-CommerceTop of Form Move over "E" and "M" so we can introduce "F-Commerce," which should go mainstream in 2011. Already several retailers have created small stores on Facebook, and it won't be long before Facebook becomes a full-fledged channel in the omni-channel world of retail. The battle between Facebook and Google will heat up over retail, where both stand to make lots of money. JCPenney and ASOS both put their entire catalogs on Facebook, and lots of other retailers have connected Facebook to their e-commerce site. I still think selling from the newsfeed is the best approach, and several retailers are trying that approach as well. I just don’t see Google+ as a threat to Facebook, so I think that battle is over.  I called 2011 The Year of F-Commerce, and that was probably accurate. Its good to look back at predictions, but we also have to think about what was missed.  I didn't see Amazon entering the tablet business with such a splash, although in hindsight it was obvious. Nor did I think HP would fall so far so fast.  Look for my 2012 predictions coming soon.

    Read the article

  • DBA Best Practices - A Blog Series: Episode 1 - Backups

    - by Argenis
      This blog post is part of the DBA Best Practices series, on which various topics of concern for daily database operations are discussed. Your feedback and comments are very much welcome, so please drop by the comments section and be sure to leave your thoughts on the subject. Morning Coffee When I was a DBA, the first thing I did when I sat down at my desk at work was checking that all backups had completed successfully. It really was more of a ritual, since I had a dual system in place to check for backup completion: 1) the scheduled agent jobs to back up the databases were set to alert the NOC in failure, and 2) I had a script run from a central server every so often to check for any backup failures. Why the redundancy, you might ask. Well, for one I was once bitten by the fact that database mail doesn't work 100% of the time. Potential causes for failure include issues on the SMTP box that relays your server email, firewall problems, DNS issues, etc. And so to be sure that my backups completed fine, I needed to rely on a mechanism other than having the servers do the taking - I needed to interrogate the servers and ask each one if an issue had occurred. This is why I had a script run every so often. Some of you might have monitoring tools in place like Microsoft System Center Operations Manager (SCOM) or similar 3rd party products that would track all these things for you. But at that moment, we had no resort but to write our own Powershell scripts to do it. Now it goes without saying that if you don't have backups in place, you might as well find another career. Your most sacred job as a DBA is to protect the data from a disaster, and only properly safeguarded backups can offer you peace of mind here. "But, we have a cluster...we don't need backups" Sadly I've heard this line more than I would have liked to. You need to understand that a cluster is comprised of shared storage, and that is precisely your single point of failure. A cluster will protect you from an issue at the Operating System level, and also under an outage of any SQL-related service or dependent devices. But it will most definitely NOT protect you against corruption, nor will it protect you against somebody deleting data from a table - accidentally or otherwise. Backup, fine. How often do I take a backup? The answer to this is something you will hear frequently when working with databases: it depends. What does it depend on? For one, you need to understand how much data your business is willing to lose. This is what's called Recovery Point Objective, or RPO. If you don't know how much data your business is willing to lose, you need to have an honest and realistic conversation about data loss expectations with your customers, internal or external. From my experience, their first answer to the question "how much data loss can you withstand?" will be "zero". In that case, you will need to explain how zero data loss is very difficult and very costly to achieve, even in today's computing environments. Do you want to go ahead and take full backups of all your databases every hour, or even every day? Probably not, because of the impact that taking a full backup can have on a system. That's what differential and transaction log backups are for. Have I answered the question of how often to take a backup? No, and I did that on purpose. You need to think about how much time you have to recover from any event that requires you to restore your databases. This is what's called Recovery Time Objective. Again, if you go ask your customer how long of an outage they can withstand, at first you will get a completely unrealistic number - and that will be your starting point for discussing a solution that is cost effective. The point that I'm trying to get across is that you need to have a plan. This plan needs to be practiced, and tested. Like a football playbook, you need to rehearse the moves you'll perform when the time comes. How often is up to you, and the objective is that you feel better about yourself and the steps you need to follow when emergency strikes. A backup is nothing more than an untested restore Backups are files. Files are prone to corruption. Put those two together and realize how you feel about those backups sitting on that network drive. When was the last time you restored any of those? Restoring your backups on another box - that, by the way, doesn't have to match the specs of your production server - will give you two things: 1) peace of mind, because now you know that your backups are good and 2) a place to offload your consistency checks with DBCC CHECKDB or any of the other DBCC commands like CHECKTABLE or CHECKCATALOG. This is a great strategy for VLDBs that cannot withstand the additional load created by the consistency checks. If you choose to offload your consistency checks to another server though, be sure to run DBCC CHECKDB WITH PHYSICALONLY on the production server, and if you're using SQL Server 2008 R2 SP1 CU4 and above, be sure to enable traceflags 2562 and/or 2549, which will speed up the PHYSICALONLY checks further - you can read more about this enhancement here. Back to the "How Often" question for a second. If you have the disk, and the network latency, and the system resources to do so, why not backup the transaction log often? As in, every 5 minutes, or even less than that? There's not much downside to doing it, as you will have to clear the log with a backup sooner than later, lest you risk running out space on your tlog, or even your drive. The one drawback to this approach is that you will have more files to deal with at restore time, and processing each file will add a bit of extra time to the entire process. But it might be worth that time knowing that you minimized the amount of data lost. Again, test your plan to make sure that it matches your particular needs. Where to back up to? Network share? Locally? SAN volume? This is another topic where everybody has a favorite choice. So, I'll stick to mentioning what I like to do and what I consider to be the best practice in this regard. I like to backup to a SAN volume, i.e., a drive that actually lives in the SAN, and can be easily attached to another server in a pinch, saving you valuable time - you wouldn't need to restore files on the network (slow) or pull out drives out a dead server (been there, done that, it’s also slow!). The key is to have a copy of those backup files made quickly, and, if at all possible, to a remote target on a different datacenter - or even the cloud. There are plenty of solutions out there that can help you put such a solution together. That right there is the first step towards a practical Disaster Recovery plan. But there's much more to DR, and that's material for a different blog post in this series.

    Read the article

  • First PC Build (Part 1)

    - by Anthony Trudeau
    Originally posted on: http://geekswithblogs.net/tonyt/archive/2014/08/05/157959.aspxA couple of months ago I made the decision to build myself a new computer. The intended use is gaming and for using the last real version of Photoshop. I was motivated by the poor state of console gaming and a simple desire to do something I haven’t done before – build a PC from the ground up. I’ve been using PCs for more than two decades. I’ve replaced a component hear and there, but for the last 10 years or so I’ve only used laptops. Therefore, this article will be written from the perspective of someone familiar with PCs, but completely new at building. I’m not an expert and this is not a definitive guide for building a PC, but I do hope that it encourages you to try it yourself. Component List Research There was a lot of research necessary, because building a PC is completely new to me, and I haven’t kept up with what’s out there. The first thing you want to do is nail down what your goals are. Your goals are going to be driven by what you want to do with your computer and personal choice. Don’t neglect the second one, because if you’re doing this for fun you want to get what you want. In my case, I focused on three things: performance, longevity, and aesthetics. The performance aspect is important for gaming and Photoshop. This will drive what components you get. For example, heavy gaming use is going to drive your choice of graphics card. Longevity is relevant to me, because I don’t want to be changing things out anytime soon for the next hot game. The consequence of performance and longevity is cost. Finally, aesthetics was my next consideration. I could have just built a box, but it wouldn’t have been nearly as fun for me. Aesthetics might not be important to you. They are for me. I also like gadgets and that played into at least one purchase for this build. I used PC Part Picker to put together my component list. I found it invaluable during the process and I’d recommend it to everyone. One caveat is that I wouldn’t trust the compatibility aspects. It does a pretty good job of not steering you wrong, but do your own research. The rest of it isn’t really sexy. I started out with what appealed to me and then I made changes and additions as I dived deep into researching each component and interaction I could find. The resources I used are innumerable. I used reviews, product descriptions, forum posts (praises and problems), et al. to assist me. I also asked friends into gaming what they thought about my component list. And when I got near the end I posted my list to the Reddit /r/buildapc forum. I cannot stress the value of extra sets of eyeballs and first hand experiences. Some of the resources I used: PC Part Picker Tom’s Hardware bit-tech Reddit Purchase PC Part Picker favors certain vendors. You should look at others too. In my case I found their favorites to be the best. My priorities were out-the-door price and shipping time. I knew that once I started getting parts I’d want to start building. Luckily, I timed it well and everything arrived within the span of a few days. Here are my opinions on the vendors I ended up using in alphabetical order. Amazon.com is a good, reliable choice. They have excellent customer service in my experience, and I knew I wouldn’t have trouble with them. However, shipping time is often a problem when you use their free shipping unless you order expensive items (I’ve found items over $100 ship quickly). Ultimately though, price wasn’t always the best and their collection of sales tax in my state turned me off them. I did purchase my case from them. I ordered the mouse as well, but I cancelled after it was stuck four days in a “shipping soon” state. I purchased the mouse locally. Best Buy is not my favorite place to do business. There’s a lot of history with poor, uninterested sales representatives and they used to have a lot of bad anti-consumer policies. That’s a lot better now, but the bad taste is still in my mouth. I ended up purchasing the accessories from them including mouse (locally) and headphones. NCIX is a company that I’ve never heard of before. It popped up as a recommendation for my CPU cooler on PC Part Picker. I didn’t do a lot of research on the company, because their policy on you buying insurance for your orders turned me off. That policy makes it clear to me that the company finds me responsible for the shipment once it leaves their dock. That’s not right, and may run afoul of state laws. Regardless they shipped my CPU cooler quickly and I didn’t have a problem. NewEgg.com is a well known company. I had never done business with them, but I’m glad I did. They shipped quickly and provided good visibility over everything. The prices were also the best in most cases. My main complaint is that they have a lot of exchange only return policies on components. To their credit those policies are listed in the cart underneath each item. The visibility tells me that they’re not playing any shenanigans and made me comfortable dealing with that risk. The vast majority of what I ordered came from them. Coming Next In the next part I’ll tackle my build experience.

    Read the article

  • Looking into the JQuery Overlays Plugin

    - by nikolaosk
    I have been using JQuery for a couple of years now and it has helped me to solve many problems on the client side of web development.  You can find all my posts about JQuery in this link. In this post I will be providing you with a hands-on example on the JQuery Overlays Plugin.If you want you can have a look at this post, where I describe the JQuery Cycle Plugin.You can find another post of mine talking about the JQuery Carousel Lite Plugin here. Another post of mine regarding the JQuery Image Zoom Plugin can be found here.I will be writing more posts regarding the most commonly used JQuery Plugins. With the JQuery Overlays Plugin we can provide the user (overlay) with more information about an image when the user hovers over the image. I have been using extensively this plugin in my websites. In this hands-on example I will be using Expression Web 4.0.This application is not a free application. You can use any HTML editor you like. You can use Visual Studio 2012 Express edition. You can download it here.  You can download this plugin from this link. I launch Expression Web 4.0 and then I type the following HTML markup (I am using HTML 5) <html lang="en"> <head>    <link rel="stylesheet" href="ImageOverlay.css" type="text/css" media="screen" />    <script type="text/javascript" src="jquery-1.8.3.min.js"></script>    <script type="text/javascript" src="jquery.ImageOverlay.min.js"></script>         <script type="text/javascript">        $(function () {            $("#Liverpool").ImageOverlay();        });    </script>   </head><body>    <ul id="Liverpool" class="image-overlay">        <li>            <a href="www.liverpoolfc.com">                <img alt="Liverpool" src="championsofeurope.jpg" />                <div class="caption">                    <h3>Liverpool Football club</h3>                    <p>The greatest club in the world</p>                </div>            </a>        </li>    </ul></body></html> This is a very simple markup. I have added references to the JQuery library (current version is 1.8.3) and the JQuery Overlays Plugin. Then I add 1 image in the element with "id=Liverpool". There is a caption class as well, where I place the text I want to show when the mouse hovers over the image. The caption class and the Liverpool id element are styled in the ImageOverlay.css file that can also be downloaded with the plugin.You can style the various elements of the html markup in the .css file. The Javascript code that makes it all happen follows.   <script type="text/javascript">        $(function () {            $("#Liverpool").ImageOverlay();        });    </script>        I am just calling the ImageOverlay function for the Liverpool ID element.The contents of ImageOverlay.css file follow .image-overlay { list-style: none; text-align: left; }.image-overlay li { display: inline; }.image-overlay a:link, .image-overlay a:visited, .image-overlay a:hover, .image-overlay a:active { text-decoration: none; }.image-overlay a:link img, .image-overlay a:visited img, .image-overlay a:hover img, .image-overlay a:active img { border: none; }.image-overlay a{    margin: 9px;    float: left;    background: #fff;    border: solid 2px;    overflow: hidden;    position: relative;}.image-overlay img{    position: absolute;    top: 0;    left: 0;    border: 0;}.image-overlay .caption{    float: left;    position: absolute;    background-color: #000;    width: 100%;    cursor: pointer;    /* The way to change overlay opacity is the follow properties. Opacity is a tricky issue due to        longtime IE abuse of it, so opacity is not offically supported - use at your own risk.         To play it safe, disable overlay opacity in IE. */    /* For Firefox/Opera/Safari/Chrome */    opacity: .8;    /* For IE 5-7 */    filter: progid:DXImageTransform.Microsoft.Alpha(Opacity=80);    /* For IE 8 */    -MS-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=80)";}.image-overlay .caption h1, .image-overlay .caption h2, .image-overlay .caption h3,.image-overlay .caption h4, .image-overlay .caption h5, .image-overlay .caption h6{    margin: 10px 0 10px 2px;    font-size: 26px;    font-weight: bold;    padding: 0 0 0 5px;    color:#92171a;}.image-overlay p{    text-indent: 0;    margin: 10px;    font-size: 1.2em;} It couldn't be any simpler than that. I view my simple page in Internet Explorer 10 and it works as expected. I have tested this simple solution in all major browsers and it works fine.Have a look at the picture below. You can test it yourself and see the results in your favorite browser. Hope it helps!!!

    Read the article

  • To SYNC or not to SYNC – Part 3

    - by AshishRay
    I can't believe it has been almost a year since my last blog post. I know, that's an absolute no-no in the blogosphere. And I know that "I have been busy" is not a good excuse. So - without trying to come up with an excuse - let me state this - my apologies for taking such a long time to write the next Part. Without further ado, here goes. This is Part 3 of a multi-part blog article where we are discussing various aspects of setting up Data Guard synchronous redo transport (SYNC). In Part 1 of this article, I debunked the myth that Data Guard SYNC is similar to a two-phase commit operation. In Part 2, I discussed the various ways that network latency may or may not impact a Data Guard SYNC configuration. In this article, I will talk in details regarding why Data Guard SYNC is a good thing. I will also talk about distance implications for setting up such a configuration. So, Why Good? Why is Data Guard SYNC a good thing? Because, at the end of the day, this gives you the assurance of zero data loss - it doesn’t matter what outage may befall your primary system. Befall! Boy, that sounds theatrical. But seriously - think about this - it minimizes your data risks. That’s a big deal. Whether you have an outage due to bad disks, faulty hardware components, hardware / software bugs, physical data corruptions, power failures, lightning that takes out significant part of your data center, fire that melts your assets, water leakage from the cooling system, human errors such as accidental deletion of online redo log files - it doesn’t matter - you can have that “Om - peace” look on your face and then you can failover to the standby system, without losing a single bit of data in your Oracle database. You will be a hero, as shown in this not so imaginary conversation: IT Manager: Well, what’s the status? You: John is doing the trace analysis on the storage array. IT Manager: So? How long is that gonna take? You: Well, he is stuck, waiting for a response from <insert your not-so-favorite storage vendor here>. IT Manager: So, no root cause yet? You: I told you, he is stuck. We have escalated with their Support, but you know how long these things take. IT Manager: Darn it - the site is down! You: Not really … IT Manager: What do you mean? You: John is stuck, but Sreeni has already done a failover to the Data Guard standby. IT Manager: Whoa, whoa - wait! Failover means we lost some data, why did you do this without letting the Business group know? You: We didn’t lose any data. Remember, we had set up Data Guard with SYNC? So now, any problems on the production – we just failover. No data loss, and we are up and running in minutes. The Business guys don’t need to know. IT Manager: Wow! Are we great or what!! You: I guess … Ok, so you get it - SYNC is good. But as my dear friend Larry Carpenter says, “TANSTAAFL”, or "There ain't no such thing as a free lunch". Yes, of course - investing in Data Guard SYNC means that you have to invest in a low-latency network, you have to monitor your applications and database especially in peak load conditions, and you cannot under-provision your standby systems. But all these are good and necessary things, if you are supporting mission-critical apps that are supposed to be running 24x7. The peace of mind that this investment will give you is priceless, especially if you are serious about HA. How Far Can We Go? Someone may say at this point - well, I can’t use Data Guard SYNC over my coast-to-coast deployment. Most likely - true. So how far can you go? Well, we have customers who have deployed Data Guard SYNC over 300+ miles! Does this mean that you can also deploy over similar distances? Duh - no! I am going to say something here that most IT managers don’t like to hear - “It depends!” It depends on your application design, application response time / throughput requirements, network topology, etc. However, because of the optimal way we do SYNC, customers have been able to stretch Data Guard SYNC deployments over longer distances compared to traditional, storage-centric ways of doing this. The MAA Database 10.2 best practices paper Data Guard Redo Transport & Network Configuration, and Oracle Database 11.2 High Availability Best Practices Manual talk about some of these SYNC-related metrics. For example, a test deployment of Data Guard SYNC over 330 miles with 10ms latency showed an impact less than 5% for a busy OLTP application. Even if you can’t deploy Data Guard SYNC over your WAN distance, or if you already have an ASYNC standby located 1000-s of miles away, here’s another nifty way to boost your HA. Have a local standby, configured SYNC. How local is “local”? Again - it depends. One customer runs a local SYNC standby across the campus. Another customer runs it across 15 miles in another data center. Both of these customers are running Data Guard SYNC as their HA standard. If a localized outage affects their primary system, no problem! They have all the data available on the standby, to which they can failover. Very fast. In seconds. Wait - did I say “seconds”? Yes, Virginia, there is a Santa Claus. But you have to wait till the next blog article to find out more. I assure you tho’ that this time you won’t have to wait for another year for this.

    Read the article

< Previous Page | 51 52 53 54 55 56 57 58 59  | Next Page >