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• Matching unmatched strings based on a unknown pattern

  - by Polity

  Alright guys, i really hurt my brain over this one and i'm curious if you guys can give me any pointers towards the right direction i should be taking. The situation is this: Lets say, i have a collection of strings (let it be clear that the pattern of this strings is unknown. For a fact, i can say that the string contain only signs from the ASCII table and therefore, i dont have to worry about weird Chinese signs). For this example, i take the following collection of strings (note that the strings dont have to make any human sence so dont try figguring them out :)): "[001].[FOO].[TEST] - 'foofoo.test'", "[002].[FOO].[TEST] - 'foofoo.test'", "[003].[FOO].[TEST] - 'foofoo.test'", "[001].[FOO].[TEST] - 'foofoo.test.sample'", "[002].[FOO].[TEST] - 'foofoo.test.sample'", "-001- BAR.[TEST] - 'bartest.xx1", "-002- BAR.[TEST] - 'bartest.xx1" Now, what i need to have is a way of finding logical groups (and subgroups) of these set of strings, so in the above example, just by rational thinking, you can combine the first 3, the 2 after that and the last 2. Also the resulting groups from the first 5 can be combined in one main group with 2 subgroups, this should give you something like this: { { "[001].[FOO].[TEST] - 'foofoo.test'", "[002].[FOO].[TEST] - 'foofoo.test'", "[003].[FOO].[TEST] - 'foofoo.test'", } { "[001].[FOO].[TEST] - 'foofoo.test.sample'", "[002].[FOO].[TEST] - 'foofoo.test.sample'", } { "-001- BAR.[TEST] - 'bartest.xx1", "-002- BAR.[TEST] - 'bartest.xx1" } } Sorry for the layout above but indenting with 4 spaces doesnt seem to work correctly (or im frakk'n it up). Anyways, I'm not sure how to approach this problem (how to get the result desired as indicated above). First of, i thought of creating a huge set of regexes which would parse most known patterns but the amount of different patterns is just to huge that this isn't realistic. Another think i thought of was parsing each indidual word within a string (so strip all non alphabetic or numeric characters and split by those), and if X% matches, i can assume the strings belong to the same group. (where X wil probably be around 80/90). However, i find the area of speculation kinda big. For example, when matching strings with each 20 words, the change of hitting above 80% is kinda big (that means that 4 words can differ), however when matching only 8 words, 2 words at most can differ. My question to you is, what would be a logical approach in the above situation? Thanks in advance!

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• Rails find over multiple models

  - by kgb

  I think I'm missing something very obvious and its making my brain hurt. class User < ActiveRecord::Base has_one :profile class Profile < ActiveRecord::Base has_one :user belongs_to :team I have a partial that loops through the users and print some basic info, I'm using this partial in my team show page. I had originally written this to return users who's profiles were a member of a team. def show @team = Team.find_by_id(params[:id]) @profiles= Profile.find(:all, :conditions => ['team_id = ?', @team.id]) @users = User.find_by_id(@profiles.user_id) end But quickly realized @profiles was an array, and it looks messy as hell. Stuck as to what my find should look like to select all User who have a profile that is a member of a team. The partial that is working elsewhere for displaying users looks like this <% for user in @users%> <table> <tr> <td> <%= image_tag user.profile.picture.url %> </td> <td> <a href="/users/<%= user.id %>"><%= user.login %></a> </td> <td> <%= user.profile.first_name %> <%= user.profile.second_name %> </td> <td> <%= user.profile.status %> </td> </tr> </table> <% end %> Development log output with updated show and relationships Processing TeamsController#show (for 127.0.0.1 at 2010-03-30 22:06:31) [GET] Parameters: {"id"=>"1"} User Load (1.3ms) SELECT * FROM "users" WHERE ("users"."id" = 3) LIMIT 1 Team Load (1.0ms) SELECT * FROM "teams" WHERE ("teams"."id" = 1) Rendering template within layouts/main Rendering teams/show Completed in 75ms (View: 11, DB: 2) | 200 OK [http://localhost/teams/1]

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• System.Net.Dns.GetHostAddresses("")

  - by dbasnett

  Yesterday s**ked, and today ain't (sic) looking better. I have an application I have been working on and it can be slow to start when my ISP is down because of DNS. My ISP was down for 3 hours yesterday, so I didn't think much about this piece of code I had added, until I found that it is always slow to start. This code is supposed to return your IP address and my reading of the link suggests that should be immediate, but it isn't, at least on my machine. Oh, and yesterday before the internet went down, I upgraded (oymoron) to XP SP3, and have had other problems. So my questions / request: 1. Am I doing this right? 2. If you run this on your machine does it take 39 seconds to return your IP address? It does on mine. One other note, I did a packet capture and the first request did NOT go on the wire, but the second did, and was answered quickly. So the question is what happened in XP SP3 that I am missing, besides a brain. One last note. If I resolve a FQDN all is well. Public Class Form1 'http://msdn.microsoft.com/en-us/library/system.net.dns.gethostaddresses.aspx ' 'excerpt 'The GetHostAddresses method queries a DNS server 'for the IP addresses associated with a host name. ' 'If hostNameOrAddress is an IP address, this address 'is returned without querying the DNS server. ' 'When an empty string is passed as the host name, 'this method returns the IPv4 addresses of the local host Private Sub Button1_Click(ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles Button1.Click Dim stpw As New Stopwatch stpw.Reset() stpw.Start() 'originally Dns.GetHostEntry, but slow also Dim myIPs() As System.Net.IPAddress = System.Net.Dns.GetHostAddresses("") stpw.Stop() Debug.WriteLine("'" & stpw.Elapsed.TotalSeconds) If myIPs.Length > 0 Then Debug.WriteLine("'" & myIPs(0).ToString) 'debug '39.8990525 '192.168.1.2 stpw.Reset() stpw.Start() 'originally Dns.GetHostEntry, but slow also myIPs = System.Net.Dns.GetHostAddresses("www.vbforums.com") stpw.Stop() Debug.WriteLine("'" & stpw.Elapsed.TotalSeconds) If myIPs.Length > 0 Then Debug.WriteLine("'" & myIPs(0).ToString) 'debug '0.042212 '63.236.73.220 End Sub End Class

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• Is this a situation where Qt Model/View architecture is not useful?

  - by csmithmaui

  Hi, I am writing a GUI based application where I read a string of values from serial port every few seconds and I need to display most of the values in some type graphical indicator(I was thinking of QprogressBar maybe) that displays the range and the value. Some of the other data that I am parsing from the string are the date and fault codes. Also, the data is hierarchical. I wanted to use the model/view architecture of Qt because I have been interested in MVC stuff for a while but have never quite wrapped my brain around how to implement it very well. As of now, I have subclassed QAbstractItemModel and in the model I read the serial port and wrap the items parsed from the string in a Tree data structure. I can view all of the data in a QtreeView with no issues. I have also began to subclass QAbstractItemView to build my custom view with all of the Graphical Indicators and such. This is where I am getting stuck. It seems to me that in order for me to design a view that knows how to display my custom model the view needs to know exactly how all of the data in the model is organized. Doesn't that defeat the purpose of Model/View? The QTreeView I tested the model with is basically just displaying the model as it is setup in the Tree structure but I don't want to do that because the data is not all of the same type. Is the type of data or the way you would like to present it to the user a determining factor in whether or not you should use this architecture? I always assumed it was just always better to design in an MVC style. It seems to me like it might have been better to just subclass QWidget and then read in from the serial port and update all of subwidgets(graphical indicators, labels, etc...) from the subclass. Essentially, do everything in one class. Does anybody understand this issue that can explain to me either what I am missing or why I shouldn't be doing it this way. As of now I am a little confused. Thanks so much for any help!

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• jQuery: Counter, Tricky problem with effects for brainy people.

  - by Marius

  Hello there! I made this counter that I think is cool because it only makes visible changes to the numbers being changed between each time it is triggered. This is the code // counter $('a').click(function(){ var u = ''; var newStr = ''; $('.counter').each(function(){ var len = $(this).children('span').length; $(this).children('span').each(function(){ u = u + $(this).text(); }); v = parseInt(u) + 1; v = v + ''; for (i=v.length - 1; i >= 0; i--) { if (v.charAt(i) == u.charAt(i)) { break; } } slce = len - (v.length - (i + 1)) updates = $(this).children('span').slice(slce); $(updates).fadeTo(100,0).delay(100).each(function(index){ f = i + 1 + index; $(this).text(v.charAt(f)); }).fadeTo(100,1); }); }); Markup: <span class="counter"> <span></span><span></span><span></span><span></span><span></span><span></span><span style="margin-right:4px;">9</span><span>9</span><span>9</span><span>9</span> </span> <a href="">Add + 1</a> The problem is that I previously used queue() function to delay() $(this).text(v.charAt(f)); by 100ms, (without queue the text()-function would not be delayed because it isnt in the fx catergory) so that the text would be updated before the object had faded to opacity = 0. That would look stupid. When adding multiple counters, only one of the counters would count. When removing the queue function, both counters would work, but as you can imagine, the delay of the text() would be gone (as it isnt fx-category). It is probably a bit tricky to make out how I can have multiple counters, and still delay the text()-function by 100ms, but I was hoping there is somebody here with spare brain capacity for these things ;) You can see a (NSFW) problem demo here: Just look underneath the sharing icons and you will notice that the text changes WHILE the objects fade out. Looking for some help to sove this problem. I would like to call the text() function once the text has faded to opacity 0, then fade in once the text() has executed. Thank you for your time.

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• Grouping php array items based on user and created time

  - by Jim

  This is an array of objects showing a user uploading photos: Array ( [12] => stdClass Object ( [type] => photo [created] => 2010-05-14 23:36:41 [user] => stdClass Object ( [id] => 760 [username] => mrsmith ) [photo] => stdClass Object ( [id] => 4181 ) ) [44] => stdClass Object ( [type] => photo [created] => 2010-05-14 23:37:15 [user] => stdClass Object ( [id] => 760 [username] => mrsmith ) [photo] => stdClass Object ( [id] => 4180 ) ) ) However instead of showing: mr smith uploaded one photo mr smith uploaded one photo I'd like to display: mr smith uploaded two photos by grouping similar items, grouping by user ID and them having added them within, let's say 15 minutes of each other. So I'd like to get the array in this sort of shape: Array ( [12] => stdClass Object ( [type] => photo [created] => 2010-05-14 23:36:41 [user] => stdClass Object ( [id] => 760 [username] => mrsmith ) [photos] => Array ( [0] => stdClass Object ( [id] => 4181 ) [1] => stdClass Object ( [id] => 4180 ) ) ) ) preserving the first item of the group and it's created time, and supplementing it with any other groupable photos and then unsetting any items that were grouped (so the final array doesn't have key 44 anymore as it was grouped in with 12). The array contains other actions than just photos, hence the original keys of 12 and 44. I just can't figure out a way to do this efficiently. I used to use MySQL and PHP to do this but am trying to just use pure PHP for caching reasons. Can anyone shed any insights? I thought about going through each item and seeing if I can group it with the previous one in the array but the previous one might not necessarily be relevant or even a photo. I've got total brain freeze :(

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• Getting jQuery slideshow animation to stop on click

  - by hollyb

  I have a slide show built with jQuery that pauses on hover. It has a group of thumbnails sitting on top of the image that advances the image when clicked, otherwise the slideshow just auto-rotates through all the images. There is also a +/- to expand and contract a caption related to each image. I want to have the slideshow's automatic advancing to stop if one of the thumbnails is clicked, or the +/-. Basically, just stop whenever a user clicks anywhere within the gallery (div class=".homeImg"). I'm having a major brain fart in getting this working properly and could use some advice. Here's the jQuery: $(document).ready(function() { $(".main_image .desc").show(); //Show image info $(".main_image .block").animate({ opacity: 0.85 }, 1 ); //Set Opacity //Click and Hover events for thumbnail list $(".image_thumb ul li:first").addClass('active'); // * Adds a class 'last' to the last li to let the rotator know when to return to the first $(".image_thumb ul li:last").addClass('last'); $(".image_thumb ul li").click(function(){ //Set Variables var imgAlt = $(this).find('img').attr("alt"); //Get Alt Tag of Image var imgTitle = $(this).find('a').attr("href"); //Get Main Image URL var imgDesc = $(this).find('.block').html(); //Get HTML of block var imgDescHeight = $(".main_image").find('.block').height(); //Calculate height of block if ($(this).is(".active")) { //If it's already active, then… return false; // Don't click through } else { //Animate $(".main_image img").animate({ opacity: 0}, 800 ); $(".main_image .block").animate({ opacity: 0, marginBottom: -imgDescHeight }, 800, function() { $(".main_image .block").html(imgDesc).animate({ opacity: 0.85, marginBottom: "0" }, 250 ); $(".main_image img").attr({ src: imgTitle , alt: imgAlt}).animate({ opacity: 1}, 250 ); }); } $(".image_thumb ul li").removeClass('active'); //Remove class of 'active' on all lists $(this).addClass('active'); //add class of 'active' on this list only return false; }) .hover(function(){ $(this).addClass('hover'); }, function() { $(this).removeClass('hover'); }); //Toggle teaser $("a.collapse").click(function(){ $(".main_image .block").slideToggle(); $("a.collapse").toggleClass("show"); return false; // added to remove # browser jump }); // If we are hovering over the image area, pause the clickNext function pauseClickNext = false; $(".homeImg").hover( function () { pauseClickNext = true; }, function () { pauseClickNext = false; } ); // Define function to click the next li var clickNext = function(){ if(!pauseClickNext) { /// find the next li after .active var $next_li = $("li.active").next("li"); if($("li.active").hasClass("last") ){ $(".image_thumb ul li:first").trigger("click"); } else { $next_li.trigger("click"); } } }; // Time between image transition setInterval(clickNext, 6000); });

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• Recursion problem; completely lost

  - by timeNomad

  So I've been trying to solve this assignment whole day, just can't get it. The following function accepts 2 strings, the 2nd (not 1st) possibly containing *'s (asterisks). An * is a replacement for a string (empty, 1 char or more), it can appear appear (only in s2) once, twice, more or not at all, it cannot be adjacent to another * (ab**c), no need to check that. public static boolean samePattern(String s1, String s2) It returns true if strings are of the same pattern. It must be recursive, not use any loops, static & global variables. Can use local variables & method overloading. Can use only these methods: charAt(i), substring(i), substring(i, j), length(). Examples: 1: TheExamIsEasy; 2: "The*xamIs*y" --- true 1: TheExamIsEasy; 2: "Th*mIsEasy*" --- true 1: TheExamIsEasy; 2: "*" --- true 1: TheExamIsEasy; 2: "TheExamIsEasy" --- true 1: TheExamIsEasy; 2: "The*IsHard" --- FALSE I tried comparing the the chars one by one using charAt until an asterisk is encountered, then check if the asterisk is an empty one by comparing is successive char (i+1) with the char of s1 at position i, if true -- continue recursion with i+1 as counter for s2 & i as counter for s1; if false -- continue recursion with i+1 as counters for both. Continue this until another asterisk is found or end of string. I dunno, my brain loses track of things, can't concentrate, any pointers / hints? Am I in the right direction? Also, it's been told that a backtracking technique is to be used to solve this. My code so far (doesn't do the job, even theoretically): public static boolean samePattern(String s1, String s2) { if (s1.equals(s2) || s2 == "*") { return true; } return samePattern(s1, s2, 1); } public static boolean samePattern(String s1, String s2, int i) { if (s1.equals(s2)) return true; if (i == s2.length() - 1) // No *'s found -- not same pattern. return false; if (s1.substring(0, i).equals(s2.substring(0, i))) samePattern(s1, s2, i+1); else if (s2.charAt(i-1) == '*') samePattern(s1.substring(0, i-1), s2.substring(0, i), 1); // new smaller strings. else samePattern(s1.substring(1), s2, i); }

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• Why does Scala apply thunks automatically, sometimes?

  - by Anonymouse

  At just after 2:40 in ShadowofCatron's Scala Tutorial 3 video, it's pointed out that the parentheses following the name of a thunk are optional. "Buh?" said my functional programming brain, since the value of a function and the value it evaluates to when applied are completely different things. So I wrote the following to try this out. My thought process is described in the comments. object Main { var counter: Int = 10 def f(): Int = { counter = counter + 1; counter } def runThunk(t: () => Int): Int = { t() } def main(args: Array[String]): Unit = { val a = f() // I expect this to mean "apply f to no args" println(a) // and apparently it does val b = f // I expect this to mean "the value f", a function value println(b) // but it's the value it evaluates to when applied to no args println(b) // and the evaluation happens immediately, not in the call runThunk(b) // This is an error: it's not println doing something funny runThunk(f) // Not an error: seems to be val doing something funny } }   To be clear about the problem, this Scheme program (and the console dump which follows) shows what I expected the Scala program to do. (define counter (list 10)) (define f (lambda () (set-car! counter (+ (car counter) 1)) (car counter))) (define runThunk (lambda (t) (t))) (define main (lambda args (let ((a (f)) (b f)) (display a) (newline) (display b) (newline) (display b) (newline) (runThunk b) (runThunk f)))) > (main) 11 #<procedure:f> #<procedure:f> 13   After coming to this site to ask about this, I came across this answer which told me how to fix the above Scala program: val b = f _ // Hey Scala, I mean f, not f() But the underscore 'hint' is only needed sometimes. When I call runThunk(f), no hint is required. But when I 'alias' f to b with a val then apply it, it doesn't work: the evaluation happens in the val; and even lazy val works this way, so it's not the point of evaluation causing this behaviour.   That all leaves me with the question: Why does Scala sometimes automatically apply thunks when evaluating them? Is it, as I suspect, type inference? And if so, shouldn't a type system stay out of the language's semantics? Is this a good idea? Do Scala programmers apply thunks rather than refer to their values so much more often that making the parens optional is better overall? Examples written using Scala 2.8.0RC3, DrScheme 4.0.1 in R5RS.

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• A NSMutableArray is destroying my life!

  - by camilo

  EDITED to show the relevant part of the code Hi. There's a strange problem with an NSMutableArray which I'm just not understanding... Explaining: I have a NSMutableArray, defined as a property (nonatomic, retain), synthesized, and initialized with 29 elements. realSectionNames = [[NSMutableArray alloc] initWithCapacity:29]; After the initialization, I can insert elements as I wish and everything seems to be working fine. While I'm running the application, however, if I insert a new element in the array, I can print the array in the function where I inserted the element, and everything seems ok. However, when I select a row in the table, and I need to read that array, my application crashes. In fact, it cannot even print the array anymore. Is there any "magical and logical trick" everybody should know when using a NSMutableArray that a beginner like myself can be missing? Thanks a lot. I declare my array as realSectionNames = [[NSMutableArray alloc] initWithCapacity:29]; I insert objects in my array with [realSectionNames addObject:[category categoryFirstLetter]]; although I know i can also insert it with [realSectionNames insertObject:[category categoryFirstLetter] atIndex:i]; where the "i" is the first non-occupied position. After the insertion, I reload the data of my tableView. Printing the array before or after reloading the data shows it has the desired information. After that, selecting a row at the table makes the application crash. This realSectionNames is used in several UITableViewDelegate functions, but for the case it doesn't matter. What truly matters is that printing the array in the beginning of the didSelectRowAtIndexPath function crashes everything (and of course, doesn't print anything). I'm pretty sure it's in that line, for printing anything he line before works (example): NSLog(@"Anything"); NSLog(@"%@", realSectionNames); gives the output: 2010-03-24 15:16:04.146 myApplicationExperience[3527:207] Anything [Session started at 2010-03-24 15:16:04 +0000.] GNU gdb 6.3.50-20050815 (Apple version gdb-967) (Tue Jul 14 02:11:58 UTC 2009) Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i386-apple-darwin".sharedlibrary apply-load-rules all Attaching to process 3527. Still not understanding what kind of stupidity I've done this time... maybe it's not too late to follow the career of brain surgeon?

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• Returning currently displayed index of an array Javascript...

  - by Jeff Kindred

  I have a simple array with x number of items. I am displaying them individually via a link click... I want to update a number that say 1 of 10. when the next one is displayed i want it to display 2 of 10 etc... I have looked all around and my brain is fried right now... I know its simple I just cant get it out. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <title>Page Title</title> <link rel="stylesheet" href="style.css" type="text/css" media="screen" charset="utf-8"/> <script type="text/javascript"> var quotations = new Array() quotations[0]= "1" quotations[1]= "2" quotations[2]= "3" quotations[3]= "4" quotations[4]= "5" quotations[5]= "6" quotations[6]= "7" numQuotes = quotations.length; curQuote = 1; function move( xflip ) { curQuote = curQuote + xflip; if (curQuote > numQuotes) { curQuote = 1 ; } if (curQuote == 0) { curQuote = numQuotes ; } document.getElementById('quotation').innerHTML=quotations[curQuote - 1]; } var curPage = //this is where the current index should go </script> </head> <body> <div id="quotation"> <script type="text/javascript">document.write(quotations[0]);</script> </div> <div> <p><a href="javascript();" onclick="move(-1)">GO back</a> <script type="text/javascript">document.write(curPage + " of " + numQuotes)</script> <a href="javascript();" onclick="move(1)">GO FORTH</a></p> </div> </body> </html>

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• boost::spirit::karma using the alternatives operator (|) with conditions

  - by Ingemar

  I'm trying to generate a string from my own class called Value using boost::spirit::karma, but i got stuck with this. I've tried to extract my problem into a simple example. I want to generate a String with karma from instances of the following class: class Value { public: enum ValueType { BoolType, NumericType }; Value(bool b) : type_(BoolType), value_(b) {} Value(const double d) : type_(NumericType), value_(d) {}; ValueType type() { return type_; } operator bool() { return boost::get<bool>(value_); } operator double() { return boost::get<double>(value_); } private: ValueType type_; boost::variant<bool, double> value_; }; Here you can see what I'm tying to do: int main() { using karma::bool_; using karma::double_; using karma::rule; using karma::eps; std::string generated; std::back_insert_iterator<std::string> sink(generated); rule<std::back_insert_iterator<std::string>, Value()> value_rule = bool_ | double_; Value bool_value = Value(true); Value double_value = Value(5.0); karma::generate(sink, value_rule, bool_value); std::cout << generated << "\n"; generated.clear(); karma::generate(sink, value_rule, double_value); std::cout << generated << "\n"; return 0; } The first call to karma::generate() works fine because the value is a bool and the first generator in my rule also "consumes" a bool. But the second karma::generate() fails with boost::bad_get because karma tries to eat a bool and calls therefore Value::operator bool(). My next thought was to modify my generator rule and use the eps() generator together with a condition but here i got stuck: value_rule = (eps( ... ) << bool_) | (eps( ... ) << double_); I'm unable to fill the brackets of the eps generator with sth. like this (of course not working): eps(value.type() == BoolType) I've tried to get into boost::phoenix, but my brain seems not to be ready for things like this. Please help me! here is my full example (compiling but not working): main.cpp

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• Refactoring Singleton Overuse

  - by drharris

  Today I had an epiphany, and it was that I was doing everything wrong. Some history: I inherited a C# application, which was really just a collection of static methods, a completely procedural mess of C# code. I refactored this the best I knew at the time, bringing in lots of post-college OOP knowledge. To make a long story short, many of the entities in code have turned out to be Singletons. Today I realized I needed 3 new classes, which would each follow the same Singleton pattern to match the rest of the software. If I keep tumbling down this slippery slope, eventually every class in my application will be Singleton, which will really be no logically different from the original group of static methods. I need help on rethinking this. I know about Dependency Injection, and that would generally be the strategy to use in breaking the Singleton curse. However, I have a few specific questions related to this refactoring, and all about best practices for doing so. How acceptable is the use of static variables to encapsulate configuration information? I have a brain block on using static, and I think it is due to an early OO class in college where the professor said static was bad. But, should I have to reconfigure the class every time I access it? When accessing hardware, is it ok to leave a static pointer to the addresses and variables needed, or should I continually perform Open() and Close() operations? Right now I have a single method acting as the controller. Specifically, I continually poll several external instruments (via hardware drivers) for data. Should this type of controller be the way to go, or should I spawn separate threads for each instrument at the program's startup? If the latter, how do I make this object oriented? Should I create classes called InstrumentAListener and InstrumentBListener? Or is there some standard way to approach this? Is there a better way to do global configuration? Right now I simply have Configuration.Instance.Foo sprinkled liberally throughout the code. Almost every class uses it, so perhaps keeping it as a Singleton makes sense. Any thoughts? A lot of my classes are things like SerialPortWriter or DataFileWriter, which must sit around waiting for this data to stream in. Since they are active the entire time, how should I arrange these in order to listen for the events generated when data comes in? Any other resources, books, or comments about how to get away from Singletons and other pattern overuse would be helpful.

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• Move an object in the direction of a bezier curve?

  - by Sent1nel

  I have an object with which I would like to make follow a bezier curve and am a little lost right now as to how to make it do that based on time rather than the points that make up the curve. .::Current System::. Each object in my scene graph is made from position, rotation and scale vectors. These vectors are used to form their corresponding matrices: scale, rotation and translation. Which are then multiplied in that order to form the local transform matrix. A world transform (Usually the identity matrix) is then multiplied against the local matrix transform. class CObject { public: // Local transform functions Matrix4f GetLocalTransform() const; void SetPosition(const Vector3f& pos); void SetRotation(const Vector3f& rot); void SetScale(const Vector3f& scale); // Local transform Matrix4f m_local; Vector3f m_localPostion; Vector3f m_localRotation; // rotation in degrees (xrot, yrot, zrot) Vector3f m_localScale; } Matrix4f CObject::GetLocalTransform() { Matrix4f out(Matrix4f::IDENTITY); Matrix4f scale(), rotation(), translation(); scale.SetScale(m_localScale); rotation.SetRotationDegrees(m_localRotation); translation.SetTranslation(m_localTranslation); out = scale * rotation * translation; } The big question I have are 1) How do I orientate my object to face the tangent of the Bezier curve? 2) How do I move that object along the curve without just setting objects position to that of a point on the bezier cuve? Heres an overview of the function thus far void CNodeControllerPieceWise::AnimateNode(CObject* pSpatial, double deltaTime) { // Get object latest pos. Vector3f posDelta = pSpatial->GetWorldTransform().GetTranslation(); // Get postion on curve Vector3f pos = curve.GetPosition(m_t); // Get tangent of curve Vector3f tangent = curve.GetFirstDerivative(m_t); } Edit: sorry its not very clear. I've been working on this for ages and its making my brain turn to mush. I want the object to be attached to the curve and face the direction of the curve. As for movement, I want to object to follow the curve based on the time this way it creates smooth movement throughout the curve.

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• two sql queries in one place

  - by Luke

  <?php $results = mysql_query("SELECT * FROM ".TBL_SUB_RESULTS." WHERE user_submitted != '$_SESSION[username]' AND home_user = '$_SESSION[username]' OR away_user = '$_SESSION[username]' ") ; $num_rows = mysql_num_rows($results); if ($num_rows > 0) { while( $row = mysql_fetch_assoc($results)) { extract($row); $q = mysql_query("SELECT name FROM ".TBL_FRIENDLY." WHERE id = '$ccompid'"); while( $row = mysql_fetch_assoc($q)) { extract($row); ?> <table cellspacing="10" style='border: 1px dotted' width="300" bgcolor="#eeeeee"> <tr> <td><b><? echo $name; ?></b></td> </tr><tr> <td width="100"><? echo $home_user; ?></td> <td width="50"><? echo $home_score; ?></td> <td>-</td> <td width="50"><? echo $away_score; ?></td> <td width="100"><? echo $away_user; ?></td> </tr><tr> <td colspan="2"><A HREF="confirmresult.php?fixid=<? echo $fix_id; ?>">Accept / Decline</a></td> </tr></table><br> <? } } } else { echo "<b>You currently have no results awaiting confirmation</b>"; } ?> I am trying to run two queries as you can see. But they aren't both working. Is there a better way to structure this, I am having a brain freeze! Thanks OOOH by the way, my SQL wont stay in this form! I will protect it afterwards

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• Restrict sprite movement to vertical and horizontal

  - by Daniel Granger

  I have been battling with this for some time and my noob brain can't quite work it out. I have a standard tile map and currently use the following code to move my enemy sprite around the map -(void) movePlayer:(ccTime)deltaTime { if (CGPointEqualToPoint(self.position, requestedPosition)) return; float step = kPlayerSpeed * deltaTime; float dist = ccpDistance(self.position, requestedPosition); CGPoint vectorBetweenAB = ccpSub(self.position, requestedPosition); if (dist <= step) { self.position = requestedPosition; [self popPosition]; } else { CGPoint normVectorBetweenAB = ccpNormalize(vectorBetweenAB); CGPoint movementVectorForThisFrame = ccpMult(normVectorBetweenAB, step); if (abs(vectorBetweenAB.x) > abs(vectorBetweenAB.y)) { if (vectorBetweenAB.x > 0) { [self runAnimation:walkLeft]; } else { [self runAnimation:walkRight]; } } else { if (vectorBetweenAB.y > 0) { [self runAnimation:walkDown]; } else { [self runAnimation:walkUp]; } } if (self.position.x > movementVectorForThisFrame.x) { movementVectorForThisFrame.x = -movementVectorForThisFrame.x; } if (self.position.y > movementVectorForThisFrame.y) { movementVectorForThisFrame.y = -movementVectorForThisFrame.y; } self.position = ccpAdd(self.position, movementVectorForThisFrame); } } movePlayer: is called by the classes updateWithDeltaTime: method. the ivar requestedPosition is set in the updateWithDeltaTime method as well, it basically gets the next point out of a queue to move to. These points can be anywhere on the map, so if they are in a diagonal direction from the enemy the enemy sprite will move directly to that point. But how do I change the above code to restrict the movement to vertical and horizontal movement only so that the enemies movement 'staircases' its way along a diagonal path, taking the manhattan distance (I think its called). As shown by my crude drawing below... S being the start point F being the finish and the numbers being each intermediate point along its path to create a staircase type diagonal movement. Finally I intend to be able to toggle this behaviour on and off, so that I can choose whether or not I want the enemy to move free around the map or be restricted to this horizontal / vertical movement only. | | | | | | | | | | | | | | | | | | | | | |F| | | | | | | | | |5|4| | | | | | | | | |3|2| | | | | | | | | |1|S| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

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• Using Upstart to manage Unicorn w/ rbenv + bundler binstubs w/ ruby-local-exec shebang

  - by codykrieger

  Alright, this is melting my brain. It might have something to do with the fact that I don't understand Upstart as well as I should. Sorry in advance for the long question. I'm trying to use Upstart to manage a Rails app's Unicorn master process. Here is my current /etc/init/app.conf: description "app" start on runlevel [2] stop on runlevel [016] console owner # expect daemon script APP_ROOT=/home/deploy/app PATH=/home/deploy/.rbenv/shims:/home/deploy/.rbenv/bin:$PATH $APP_ROOT/bin/unicorn -c $APP_ROOT/config/unicorn.rb -E production # >> /tmp/upstart.log 2>&1 end script # respawn That works just fine - the Unicorns start up great. What's not great is that the PID detected is not of the Unicorn master, it's of an sh process. That in and of itself isn't so bad, either - if I wasn't using the automagical Unicorn zero-downtime deployment strategy. Because shortly after I send -USR2 to my Unicorn master, a new master spawns up, and the old one dies...and so does the sh process. So Upstart thinks my job has died, and I can no longer restart it with restart or stop it with stop if I want. I've played around with the config file, trying to add -D to the Unicorn line (like this: $APP_ROOT/bin/unicorn -c $APP_ROOT/config/unicorn.rb -E production -D) to daemonize Unicorn, and I added the expect daemon line, but that didn't work either. I've tried expect fork as well. Various combinations of all of those things can cause start and stop to hang, and then Upstart gets really confused about the state of the job. Then I have to restart the machine to fix it. I think Upstart is having problems detecting when/if Unicorn is forking because I'm using rbenv + the ruby-local-exec shebang in my $APP_ROOT/bin/unicorn script. Here it is: #!/usr/bin/env ruby-local-exec # # This file was generated by Bundler. # # The application 'unicorn' is installed as part of a gem, and # this file is here to facilitate running it. # require 'pathname' ENV['BUNDLE_GEMFILE'] ||= File.expand_path("../../Gemfile", Pathname.new(__FILE__).realpath) require 'rubygems' require 'bundler/setup' load Gem.bin_path('unicorn', 'unicorn') Additionally, the ruby-local-exec script looks like this: #!/usr/bin/env bash # # `ruby-local-exec` is a drop-in replacement for the standard Ruby # shebang line: # # #!/usr/bin/env ruby-local-exec # # Use it for scripts inside a project with an `.rbenv-version` # file. When you run the scripts, they'll use the project-specified # Ruby version, regardless of what directory they're run from. Useful # for e.g. running project tasks in cron scripts without needing to # `cd` into the project first. set -e export RBENV_DIR="${1%/*}" exec ruby "$@" So there's an exec in there that I'm worried about. It fires up a Ruby process, which fires up Unicorn, which may or may not daemonize itself, which all happens from an sh process in the first place...which makes me seriously doubt the ability of Upstart to track all of this nonsense. Is what I'm trying to do even possible? From what I understand, the expect stanza in Upstart can only be told (via daemon or fork) to expect a maximum of two forks.

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• Compiling examples for consuming the REST Endpoints for WCF Service using Agatha

  - by REA_ANDREW

  I recently made two contributions to the Agatha Project by Davy Brion over on Google Code, and one of the things I wanted to follow up with was a post showing examples and some, seemingly required tid bits.  The contributions which I made where: To support StructureMap To include REST (JSON and XML) support for the service contract The examples which I have made, I want to format them so they fit in with the current format of examples over on Agatha and hopefully create and submit a third patch which will include these examples to help others who wish to use these additions. Whilst building these examples for both XML and JSON I have learnt a couple of things which I feel are not really well documented, but are extremely good practice and once known make perfect sense.  I have chosen a real basic e-commerce context for my example Requests and Responses, and have also made use of the excellent tool AutoMapper, again on Google Code. Setting the scene I have followed the Pipes and Filters Pattern with the IQueryable interface on my Repository and exposed the following methods to query Products: IQueryable<Product> GetProducts(); IQueryable<Product> ByCategoryName(this IQueryable<Product> products, string categoryName) Product ByProductCode(this IQueryable<Product> products, String productCode) I have an interface for the IProductRepository but for the concrete implementation I have simply created a protected getter which populates a private List<Product> with 100 test products with random data.  Another good reason for following an interface based approach is that it will demonstrate usage of my first contribution which is the StructureMap support.  Finally the two Domain Objects I have made are Product and Category as shown below: public class Product { public String ProductCode { get; set; } public String Name { get; set; } public Decimal Price { get; set; } public Decimal Rrp { get; set; } public Category Category { get; set; } }   public class Category { public String Name { get; set; } }   Requirements for the REST Support One of the things which you will notice with Agatha is that you do not have to decorate your Request and Response objects with the WCF Service Model Attributes like DataContract, DataMember etc… Unfortunately from what I have seen, these are required if you want the same types to work with your REST endpoint.  I have not tried but I assume the same result can be achieved by simply decorating the same classes with the Serializable Attribute.  Without this the operation will fail. Another surprising thing I have found is that it did not work until I used the following Attribute parameters: Name Namespace e.g. [DataContract(Name = "GetProductsRequest", Namespace = "AgathaRestExample.Service.Requests")] public class GetProductsRequest : Request { }   Although I was surprised by this, things kind of explained themselves when I got round to figuring out the exact construct required for both the XML and the REST.  One of the things which you already know and are then reminded of is that each of your Requests and Responses ultimately inherit from an abstract base class respectively. This information needs to be represented in a way native to the format being used.  I have seen this in XML but I have not seen the format which is required for the JSON. JSON Consumer Example I have used JQuery to create the example and I simply want to make two requests to the server which as you will know with Agatha are transmitted inside an array to reduce the service calls.  I have also used a tool called json2 which is again over at Google Code simply to convert my JSON expression into its string format for transmission.  You will notice that I specify the type of Request I am using and the relevant Namespace it belongs to.  Also notice that the second request has a parameter so each of these two object are representing an abstract Request and the parameters of the object describe it. <script type="text/javascript"> var bodyContent = $.ajax({ url: "http://localhost:50348/service.svc/json/processjsonrequests", global: false, contentType: "application/json; charset=utf-8", type: "POST", processData: true, data: JSON.stringify([ { __type: "GetProductsRequest:AgathaRestExample.Service.Requests" }, { __type: "GetProductsByCategoryRequest:AgathaRestExample.Service.Requests", CategoryName: "Category1" } ]), dataType: "json", success: function(msg) { alert(msg); } }).responseText; </script>   XML Consumer Example For the XML Consumer example I have chosen to use a simple Console Application and make a WebRequest to the service using the XML as a request.  I have made a crude static method which simply reads from an XML File, replaces some value with a parameter and returns the formatted XML.  I say crude but it simply shows how XML Templates for each type of Request could be made and then have a wrapper utility in whatever language you use to combine the requests which are required.  The following XML is the same Request array as shown above but simply in the XML Format. <?xml version="1.0" encoding="utf-8" ?> <ArrayOfRequest xmlns="http://schemas.datacontract.org/2004/07/Agatha.Common" xmlns:i="http://www.w3.org/2001/XMLSchema-instance"> <Request i:type="a:GetProductsRequest" xmlns:a="AgathaRestExample.Service.Requests"/> <Request i:type="a:GetProductsByCategoryRequest" xmlns:a="AgathaRestExample.Service.Requests"> <a:CategoryName>{CategoryName}</a:CategoryName> </Request> </ArrayOfRequest>   It is funny because I remember submitting a question to StackOverflow asking whether there was a REST Client Generation tool similar to what Microsoft used for their RestStarterKit but which could be applied to existing services which have REST endpoints attached.  I could not find any but this is now definitely something which I am going to build, as I think it is extremely useful to have but also it should not be too difficult based on the information I now know about the above.  Finally I thought that the Strategy Pattern would lend itself really well to this type of thing so it can accommodate for different languages. I think that is about it, I have included the code for the example Console app which I made below incase anyone wants to have a mooch at the code.  As I said above I want to reformat these to fit in with the current examples over on the Agatha project, but also now thinking about it, make a Documentation Web method…{brain ticking} :-) Cheers for now and here is the final bit of code: static void Main(string[] args) { var request = WebRequest.Create("http://localhost:50348/service.svc/xml/processxmlrequests"); request.Method = "POST"; request.ContentType = "text/xml"; using(var writer = new StreamWriter(request.GetRequestStream())) { writer.WriteLine(GetExampleRequestsString("Category1")); } var response = request.GetResponse(); using(var reader = new StreamReader(response.GetResponseStream())) { Console.WriteLine(reader.ReadToEnd()); } Console.ReadLine(); } static string GetExampleRequestsString(string categoryName) { var data = File.ReadAllText(Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location), "ExampleRequests.xml")); data = data.Replace("{CategoryName}", categoryName); return data; } }

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• AutoMapper MappingFunction from Source Type of NameValueCollection

  - by REA_ANDREW

  I have had a situation arise today where I need to construct a complex type from a source of a NameValueCollection.  A little while back I submitted a patch for the Agatha Project to include REST (JSON and XML) support for the service contract.  I realized today that as useful as it is, it did not actually support true REST conformance, as REST should support GET so that you can use JSONP from JavaScript directly meaning you can query cross domain services.  My original implementation for POX and JSON used the POST method and this immediately rules out JSONP as from reading, JSONP only works with GET Requests. This then raised another issue.  The current operation contract of Agatha and one of its main benefits is that you can supply an array of Request objects in a single request, limiting the about of server requests you need to make.  Now, at the present time I am thinking that this will not be the case for the REST imlementation but will yield the benefits of the fact that : The same Request objects can be used for SOAP and RST (POX, JSON) The construct of the JavaScript functions will be simpler and more readable It will enable the use of JSONP for cross domain REST Services The current contract for the Agatha WcfRequestProcessor is at time of writing the following: [ServiceContract] public interface IWcfRequestProcessor { [OperationContract(Name = "ProcessRequests")] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] [TransactionFlow(TransactionFlowOption.Allowed)] Response[] Process(params Request[] requests); [OperationContract(Name = "ProcessOneWayRequests", IsOneWay = true)] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] void ProcessOneWayRequests(params OneWayRequest[] requests); }   My current proposed solution, and at the very early stages of my concept is as follows: [ServiceContract] public interface IWcfRestJsonRequestProcessor { [OperationContract(Name="process")] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] [TransactionFlow(TransactionFlowOption.Allowed)] [WebGet(UriTemplate = "process/{name}/{*parameters}", BodyStyle = WebMessageBodyStyle.WrappedResponse, ResponseFormat = WebMessageFormat.Json)] Response[] Process(string name, NameValueCollection parameters); [OperationContract(Name="processoneway",IsOneWay = true)] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] [WebGet(UriTemplate = "process-one-way/{name}/{*parameters}", BodyStyle = WebMessageBodyStyle.WrappedResponse, ResponseFormat = WebMessageFormat.Json)] void ProcessOneWayRequests(string name, NameValueCollection parameters); }   Now this part I have not yet implemented, it is the preliminart step which I have developed which will allow me to take the name of the Request Type and the NameValueCollection and construct the complex type which is that of the Request which I can then supply to a nested instance of the original IWcfRequestProcessor  and work as it should normally.  To give an example of some of the urls which you I envisage with this method are: http://www.url.com/service.svc/json/process/getweather/?location=london http://www.url.com/service.svc/json/process/getproductsbycategory/?categoryid=1 http://www.url.om/service.svc/json/process/sayhello/?name=andy Another reason why my direction has gone to a single request for the REST implementation is because of restrictions which are imposed by browsers on the length of the url.  From what I have read this is on average 2000 characters.  I think that this is a very acceptable usage limit in the context of using 1 request, but I do not think this is acceptable for accommodating multiple requests chained together.  I would love to be corrected on that one, I really would but unfortunately from what I have read I have come to the conclusion that this is not the case. The mapping function So, as I say this is just the first pass I have made at this, and I am not overly happy with the try catch for detecting types without default constructors.  I know there is a better way but for the minute, it escapes me.  I would also like to know the correct way for adding mapping functions and not using the anonymous way that I have used.  To achieve this I have used recursion which I am sure is what other mapping function use. As you do have to go as deep as the complex type is. public static object RecurseType(NameValueCollection collection, Type type, string prefix) { try { var returnObject = Activator.CreateInstance(type); foreach (var property in type.GetProperties()) { foreach (var key in collection.AllKeys) { if (String.IsNullOrEmpty(prefix) || key.Length > prefix.Length) { var propertyNameToMatch = String.IsNullOrEmpty(prefix) ? key : key.Substring(property.Name.IndexOf(prefix) + prefix.Length + 1); if (property.Name == propertyNameToMatch) { property.SetValue(returnObject, Convert.ChangeType(collection.Get(key), property.PropertyType), null); } else if(property.GetValue(returnObject,null) == null) { property.SetValue(returnObject, RecurseType(collection, property.PropertyType, String.Concat(prefix, property.PropertyType.Name)), null); } } } } return returnObject; } catch (MissingMethodException) { //Quite a blunt way of dealing with Types without default constructor return null; } }   Another thing is performance, I have not measured this in anyway, it is as I say the first pass, so I hope this can be the start of a more perfected implementation.  I tested this out with a complex type of three levels, there is no intended logical meaning to the properties, they are simply for the purposes of example.  You could call this a spiking session, as from here on in, now I know what I am building I would take a more TDD approach.  OK, purists, why did I not do this from the start, well I didn’t, this was a brain dump and now I know what I am building I can. The console test and how I used with AutoMapper is as follows: static void Main(string[] args) { var collection = new NameValueCollection(); collection.Add("Name", "Andrew Rea"); collection.Add("Number", "1"); collection.Add("AddressLine1", "123 Street"); collection.Add("AddressNumber", "2"); collection.Add("AddressPostCodeCountry", "United Kingdom"); collection.Add("AddressPostCodeNumber", "3"); AutoMapper.Mapper.CreateMap<NameValueCollection, Person>() .ConvertUsing(x => { return(Person) RecurseType(x, typeof(Person), null); }); var person = AutoMapper.Mapper.Map<NameValueCollection, Person>(collection); Console.WriteLine(person.Name); Console.WriteLine(person.Number); Console.WriteLine(person.Address.Line1); Console.WriteLine(person.Address.Number); Console.WriteLine(person.Address.PostCode.Country); Console.WriteLine(person.Address.PostCode.Number); Console.ReadLine(); }   Notice the convention that I am using and that this method requires you do use.  Each property is prefixed with the constructed name of its parents combined.  This is the convention used by AutoMapper and it makes sense. I can also think of other uses for this including using with ASP.NET MVC ModelBinders for creating a complex type from the QueryString which is itself is a NameValueCollection. Hope this is of some help to people and I would welcome any code reviews you could give me. References: Agatha : http://code.google.com/p/agatha-rrsl/ AutoMapper : http://automapper.codeplex.com/   Cheers for now, Andrew   P.S. I will have the proposed solution for a more complete REST implementation for AGATHA very soon. 

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• Interesting things – Twitter annotations and your phone as a web server

  - by jamiet

  I overheard/read a couple of things today that really made me, data junkie that I am, take a step back and think, “Hmmm, yeah, that could be really interesting” and I wanted to make a note of them here so that (a) I could bring them to the attention of anyone that happens to read this and (b) I can maybe come back here in a few years and see if either of these have come to fruition. Your phone as a web server While listening to Jon Udell’s (twitter) “Interviews with Innovators Podcast” today in which he interviewed Herbert Van de Sompel (twitter) about his Momento project. During the interview Jon and Herbert made the following remarks: Jon: [some people] really had this vision of a web of servers, the notion that every node on the internet, every connected entity, is potentially a server and a client…we can see where we’re getting to a point where these endpoint devices we have in our pockets are going to be massively capable and it may be in the not too distant future that significant chunks of the web archive will be cached all over the place including on your own machine… Herbert: wasn’t it Opera who at one point turned your browser into a server? That really got my brain ticking. We all carry a mobile phone with us and therefore we all potentially carry a mobile web server with us as well and to my mind the only thing really stopping that from happening is the capabilities of the phone hardware, the capabilities of the network infrastructure and the will to just bloody do it. Certainly all the standards required for addressing a web server on a phone already exist (to this uninitiated observer DNS and IPv6 seem to solve that problem) so why not? I tweeted about the idea and Rory Street answered back with “why would you want a phone to be a web server?”: Its a fair question and one that I would like to try and answer. Mobile phones are increasingly becoming our window onto the world as we use them to upload messages to Twitter, record our location on FourSquare or interact with our friends on Facebook but in each of these cases some other service is acting as our intermediary; to see what I’m thinking you have to go via Twitter, to see where I am you have to go to FourSquare (I’m using ‘I’ liberally, I don’t actually use FourSquare before you ask). Why should this have to be the case? Why can’t that data be decentralised? Why can’t we be masters of our own data universe? If my phone acted as a web server then I could expose all of that information without needing those intermediary services. I see a time when we can pass around URLs such as the following: http://jamiesphone.net/location/current - Where is Jamie right now? http://jamiesphone.net/location/2010-04-21 – Where was Jamie on 21st April 2010? http://jamiesphone.net/thoughts/current – What’s on Jamie’s mind right now? http://jamiesphone.net/blog – What documents is Jamie sharing with me? http://jamiesphone.net/calendar/next7days – Where is Jamie planning to be over the next 7 days? and those URLs get served off of the phone in our pockets. If we govern that data then we can control who has access to it and (crucially) how long its available for. Want to wipe yourself off the face of the web? its pretty easy if you’re in control of all the data – just turn your phone off. None of this exists today but I look forward to a time when it does. Opera really were onto something last June when they announced Opera Unite (admittedly Unite only works because Opera provide an intermediary DNS-alike system – it isn’t totally decentralised). Opening up Twitter annotations Last week Twitter held their first developer conference called Chirp where they announced an upcoming new feature called ‘Twitter Annotations’; in short this will allow us to attach metadata to a Tweet thus enhancing the tweet itself. Think of it as a richer version of hashtags. To think of it another way Twitter are turning their data into a humongous Entity-Attribute-Value or triple-tuple store. That alone has huge implications both for the web and Twitter as a whole – the ability to enrich that 140 characters data and thus make it more useful is indeed compelling however today I stumbled upon a blog post from Eugene Mandel entitled Tweet Annotations – a Way to a Metadata Marketplace? where he proposed the idea of allowing tweets to have metadata added by people other than the person who tweeted the original tweet. This idea really fascinated me especially when I read some of the potential uses that Eugene and his commenters suggested. They included: Amazon could attach an ISBN to a tweet that mentions a book. Specialist clients apps for book lovers could be built up around this metadata. Advertisers could pay to place adverts in metadata. The revenue generated from those adverts could be shared with the tweeter or people who add the metadata. Granted, allowing anyone to add metadata to a tweet has the potential to create a spam problem the like of which we haven’t even envisaged but spam hasn’t halted the growth of the web and neither should it halt the growth of data annotations either. The original tweeter should of course be able to determine who can add metadata and whether it should be moderated. As Eugene says himself: Opening publishing tweet annotations to anyone will open the way to a marketplace of metadata where client developers, data mining companies and advertisers can add new meaning to Twitter and build innovative businesses. What Eugene and his followers did not mention is what I think is potentially the most fascinating use of opening up annotations. Google’s success today is built on their page rank algorithm that measures the validity of a web page by the number of incoming links to it and the page rank of the sites containing those links – its a system built on reputation. Twitter annotations could open up a new paradigm however – let’s call it People rank- where reputation can be measured by the metadata that people choose to apply to links and the websites containing those links. Its not hard to see why Google and Microsoft have paid big bucks to get access to the Twitter firehose! Neither of these features, phones as a web server or the ability to add annotations to other people’s tweets, exist today but I strongly believe that they could dramatically enhance the web as we know it today. I hope to look back on this blog post in a few years in the knowledge that these ideas have been put into place. @Jamiet Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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• I&rsquo;m sorry RPGs, it&rsquo;s not you, it&rsquo;s me: The birth of my game idea

  - by George Clingerman

  One of the things I’ve had to give up in order to have some development time at night is gaming. It’s something I refused to admit for years but I’ve just had to face the facts. I’m no longer a gamer. I just don’t have hours and hours of free time to pour into gaming and when I do have hours and hours of free time I want to pour them into game development. That doesn’t mean I don’t game at all! I play games pretty much every day. It just means I’ve moved more into the casual game realm. It’s all I have time for when juggling priorities in my life. That means that games like Gears of War 2 sit shrink wrapped on my shelf and although I popped Dragon Age into my Xbox 360 one time, I barely made it through the opening sequence and haven’t had time to sit down and play again. Instead I’m playing short games like Jamestown, Atom Zombie Smasher, Fortix or if I have time to jump in and play a few rounds maybe some Monday Night Combat or Team Fortress 2. These are games I can instantly get into and play for just a short period of time and then walk away. Breath of Death VII saved my life: Back in the day (way, way back in the day) I used to be a pretty big RPG fan. Not big by a lot of RPG gamers' standards (most of the RPGs RPG fans about I’ve never heard of) but I used to LOVE to play them on the NES, SNES and Genesis and considered that my genre. Final Fantasy, Shining in the Darkness, Bard’s Tale, Faxanadu, Shadowrun, Ultima, Dragon Warrior, Chrono Trigger, Phantasy Star, Shining Force and well the list could go on but those are the ones I remember off the top of my head. I loved playing RPGs and they were my games of choice. After my first son was born (this was just about 12 years ago), I tried to continue playing RPGs and purchased games like Baldur’s Gate I & II, Neverwinter Nights, Fable, then a few of the Final Fantasy’s then Kingdom Hearts. I kept buying these games and then only playing for about fifteen minutes and never getting back to them. I still loved RPGs but they just no longer fit into my life (I still haven’t accepted that since I still purchased Dragon Age II for some reason and convinced myself I’d find the time). Adding three more sons to the mix (that’s 4 total) didn’t help much to finding more RPG time (except for Breath of Death VII and other XBLIG RPG titles, thanks guys!) All work and no RPG: A few months ago as I was sitting thinking about the lack of RPGs in my life and talking to my wife about why I wish RPGs were different and easier for a dad like me to get into. She seemed like she was listening, so I started listing all the things that made them impossible for me to play. Here’s a short list I came up with. They take 15 billion hours to complete I have a few minutes at a time I can grab to play them if I want to have time to code. At that rate it would take me 9 trillion years to beat just one RPG. There’s such long spans of times between when I can play them I forget what I was even doing so I have to spend most of the playtime I have just figuring that out and then my play time is over. Repeat. I’ll never finish one and since it takes so long to get to the fun part in an RPG, I’m never having fun. RPGs aren’t fun if you don’t have hours to play them at a time. As you can see based on my science and math, RPGs aren’t fun for me any more. From there my brain started toying around with ideas of RPGs that would work for me. They would have to be a short RPG, you know one you could beat in a single play session. A dad sized play session. I started thinking, wouldn’t it be awesome if there was a fifteen minute RPG? That got me laughing and I took that as a good sign that it sounded fun and so I thought about it a little more. I immediately discarded the idea of doing a real RPG. I’m sure a short RPG like that could be done but it wasn’t the vibe that I had in my head. No this was going to be something that just had the core essence of an RPG. In reality what I’d be making would be more of an arcade style game. One with high scores and lots of crazy action on the screen. And that’s when it hit me. It would be a speed run RPG. That’s the basics of the game I’m working on.   The Elevator Pitch: It’s a 2D top down RPG themed arcade game focused on speed. It sounds like an RPG, smells like an RPG but it’s merely emulating an RPG. The game is focused on fun and mayhem in RPG form with players leveling up in seconds instead of hours and rushing to finish quests as quickly as possible because they’ve only got fifteen minutes before EVIL overtakes the world. If the player takes longer than fifteen minutes, it’s game over man. One to four player co-operative play to really see just how fast players can level up and beat the game. Gamers will compete on leaderboards for bragging rights for fastest 1, 2, 3, and 4 player speed runs, lowest leveled characters to beat the game, highest leveled characters to beat the game and so on. Times will be tracked for everything from how long a player sat distributing stats, equipping items, talking to NPCs to running around the level. These stats will be shown at the end of each quest/level so the players can work on improving their speed run for that part of the game next time around. It’s the perfect RPG for those of us who only have fifteen minutes of game time! Where I’m at: I’m still at the prototyping stage attempting to but all the basic framework pieces in place that will at minimum give me one level to rush through. I’ve been working on this prototype for about a month now though so I’m going to have to step it up a bit or I’m not going to get finished in time (remember I’ve only got 85 days left!) Lots of the game code is in place (although pretty sloppy) but I still can’t play through that first quest/level just yet. That’s my goal to finish up by the end of next Sunday (3/25/2012). You can all hold me to that and cheer me on or heckle me throughout the week. Either way that should help me stay a bit more motivated and focused. In my head this feels like it’s going to be a fun game so I’m looking forward to seeing how it actually plays!

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• Thursday Community Keynote: "By the Community, For the Community"

  - by Janice J. Heiss

  Sharat Chander, JavaOne Community Chairperson, began Thursday's Community Keynote. As part of the morning’s theme of "By the Community, For the Community," Chander noted that 60% of the material at the 2012 JavaOne conference was presented by Java Community members. "So next year, when the call for papers starts, put-in your submissions," he urged.From there, Gary Frost, Principal Member of Technical Staff, AMD, expanded upon Sunday's Strategy Keynote exploration of Project Sumatra, an OpenJDK project targeted at bringing Java to heterogeneous computing platforms (which combine the CPU and the parallel processor of the GPU into a single piece of silicon). Sumatra entails enhancing the JVM to make maximum use of these advanced platforms. Within this development space, AMD created the Aparapi API, which converts Java bytecode into OpenCL for execution on such GPU devices. The Aparapi API was open sourced in September 2011.Whether it was zooming-in on a Mandelbrot set, "the game of life," or a swarm of 10,000 Dukes in a space-bound gravitational dance, Frost's demos, using an Aparapi/OpenCL implementation, produced stunningly faster display results. He indicated that the Java 9 timeframe is where they see Project Sumatra coming to ultimate fruition, employing the Lamdas of Java 8.Returning to the theme of the keynote, Donald Smith, Director, Java Product Management, Oracle, explored a mind map graphic demonstrating the importance of Community in terms of fostering innovation. "It's the sharing and mixing of culture, the diversity, and the rapid prototyping," he said. Within this topic, Smith, brought up a panel of representatives from Cloudera, Eclipse, Eucalyptus, Perrone Robotics, and Twitter--ideal manifestations of community and innovation in the world of Java.Marten Mickos, CEO, Eucalyptus Systems, explored his company's open source cloud software platform, written in Java, and used by gaming companies, technology companies, media companies, and more. Chris Aniszczyk, Operations Engineering,Twitter, noted the importance of the JVM in terms of their multiple-language development environment. Mike Olson, CEO, Cloudera, described his company's Apache Hadoop-based software, support, and training. Mike Milinkovich, Executive Director, Eclipse Foundation, noted that they have about 270 tools projects at Eclipse, with 267 of them written in Java. Milinkovich added that Eclipse will even be going into space in 2013, as part of the control software on various experiments aboard the International Space Station. Lastly, Paul Perrone, CEO, Perrone Robotics, detailed his company's robotics and automation software platform built 100% on Java, including Java SE and Java ME--"on rat, to cat, to elephant-sized systems." Milinkovic noted that communities are by nature so good at innovation because of their very openness--"The more open you make your innovation process, the more ideas are challenged, and the more developers are focused on justifying their choices all the way through the process."From there, Georges Saab, VP Development Java SE OpenJDK, continued the topic of innovation and helping the Java Community to "Make the Future Java." Martijn Verburg, representing the London Java Community (winner of a Duke's Choice Award 2012 for their activity in OpenJDK and JCP), soon joined Saab onstage. Verburg detailed the LJC's "Adopt a JSR" program--"to get day-to-day developers more involved in the innovation that's happening around them."  From its London launching pad, the innovative program has spread to Brazil, Morocco, Latvia, India, and more.Other active participants in the program joined Verburg onstage--Ben Evans, London Java Community; James Gough, Stackthread; Bruno Souza, SOUJava; Richard Warburton, jClarity; and Cecelia Borg, Oracle--OpenJDK Onboarding. Together, the group explored the goals and tasks inherent in the Adopt a JSR program--from organizing hack days (testing prototype implementations), to managing mailing lists and forums, to triaging issues, to evangelism—all with the goal of fostering greater community/developer involvement, but equally importantly, building better open standards. “Come join us, and make your ecosystem better!" urged Verburg.Paul Perrone returned to profile the latest in his company's robotics work around Java--including the AARDBOTS family of smaller robotic vehicles, running the Perrone MAX platform on top of the Java JVM. Perrone took his "Rumbles" four-wheeled robot out for a spin onstage--a roaming, ARM-based security-bot vehicle, complete with IR, ultrasonic, and "cliff" sensors (the latter, for the raised stage at JavaOne). As an ultimate window into the future of robotics, Perrone displayed a "head-set" controller--a sensor directed at the forehead to monitor brainwaves, for the someday-implementation of brain-to-robot control.Then, just when it seemed this might be the end of the day's futuristic offerings, a mystery voice from offstage pronounced "I've got some toys"--proving to be guest-visitor James Gosling, there to explore his cutting-edge work with Liquid Robotics. While most think of robots as something with wheels or arms or lasers, Gosling explained, the Liquid Robotics vehicle is an entirely new and innovative ocean-going 'bot. Looking like a floating surfboard, with an attached set of underwater wings, the autonomous devices roam the oceans using only the energy of ocean waves to propel them, and a single actuated rudder to steer. "We have to accomplish all guidance just by wiggling the rudder," Gosling said. The devices offer applications from self-installing weather buoy, to pollution monitoring station, to marine mammal monitoring device, to climate change data gathering, to even ocean life genomic sampling. The early versions of the vehicle used C code on very tiny industrial micro controllers, where they had to "count the bytes one at a time."  But the latest generation vehicles, which just hit the water a week or so ago, employ an ARM processor running Linux and the ARM version of JDK 7. Gosling explained that vehicle communication from remote locations is achieved via the Iridium satellite network. But because of the costs of this communication path, the data must be sent in very small bursts--using SBD short burst data. "It costs $1/kb, so that rules everything in the software design,” said Gosling. “If you were trying to stream a Netflix video over this, it would cost a million dollars a movie. …We don't have a 'big data' problem," he quipped. There are currently about 150 Liquid Robotics vehicles out traversing the oceans. Gosling demonstrated real time satellite tracking of several vehicles currently at sea, noting that Java is actually particularly good at AI applications--due to the language having garbage collection, which facilitates complex data structures. To close-out his time onstage, Gosling of course participated in the ceremonial Java tee-shirt toss out to the audience…In parting, Chander passed the JavaOne Community Chairperson baton to Stephen Chin, Java Technology Evangelist, Oracle. Onstage in full motorcycle gear, Chin noted that he'll soon be touring Europe by motorcycle, meeting Java Community Members and streaming live via UStream--the ultimate manifestation of community and technology!  He also reminded attendees of the upcoming JavaOne Latin America 2012, São Paulo, Brazil (December 4-6, 2012), and stated that the CFP (call for papers) at the conference has been extended for one more week. "Remember, December is summer in Brazil!" Chin said.

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• Too Many Kittens To Juggle At Once

  - by Bil Simser

  Ahh, the Internet. That crazy, mixed up place where one tweet turns into a conversation between dozens of people and spawns a blogpost. This is the direct result of such an event this morning. It started innocently enough, with this: Then followed up by a blog post by Joel here. In the post, Joel introduces us to the term Business Solutions Architect with mad skillz like InfoPath, Access Services, Excel Services, building Workflows, and SSRS report creation, all while meeting the business needs of users in a SharePoint environment. I somewhat disagreed with Joel that this really wasn’t a new role (at least IMHO) and that a good Architect or BA should really be doing this job. As Joel pointed out when you’re building a SharePoint team this kind of role is often overlooked. Engineers might be able to build workflows but is the right workflow for the right problem? Michael Pisarek wrote about a SharePoint Business Architect a few months ago and it’s a pretty solid assessment. Again, I argue you really shouldn’t be looking for roles that don’t exist and I don’t suggest anyone create roles to hire people to fill them. That’s basically creating a solution looking for problems. Michael’s article does have some great points if you’re lost in the quagmire of SharePoint duties though (and I especially like John Ross’ quote “The coolest shit is worthless if it doesn’t meet business needs”). SharePoinTony summed it up nicely with “SharePoint Solutions knowledge is both lacking and underrated in most environments. Roles help”. Having someone on the team who can dance between a business user and a coder can be difficult. Remember the idea of telling something to someone and them passing it on to the next person. By the time the story comes round the circle it’s a shadow of it’s former self with little resemblance to the original tale. This is very much business requirements as they’re told by the user to a business analyst, written down on paper, read by an architect, tuned into a solution plan, and implemented by a developer. Transformations between what was said, what was heard, what was written down, and what was developed can be distant cousins. Not everyone has the skill of communication and even less have negotiation skills to suit the SharePoint platform. Negotiation is important because not everything can be (or should be) done in SharePoint. Sometimes it’s just not appropriate to build it on the SharePoint platform but someone needs to know enough about the platform and what limitations it might have, then communicate that (and/or negotiate) with a customer or user so it’s not about “You can’t have this” to “Let’s try it this way”. Visualize the possible instead of denying the impossible. So what is the right SharePoint team? My cromag brain came with a fairly simpleton answer (and I’m sure people will just say this is a cop-out). The perfect SharePoint team is just enough people to do the job that know the technology and business problem they’re solving. Bridge the gap between business need and technology platform and you have an architect. Communicate the needs of the business effectively so the entire team understands it and you have a business analyst. Can you get this with full time workers? Maybe but don’t expect miracles out of the gate. Also don’t take a consultant’s word as gospel. Some consultants just don’t have the diversity of the SharePoint platform to be worth their value so be careful. You really need someone who knows enough about SharePoint to be able to validate a consultants knowledge level. This is basically try for any consultant, not just a SharePoint one. Specialization is good and needed. A good, well-balanced SharePoint team is one of people that can solve problems with work with the technology, not against it. Having a top developer is great, but don’t rely on them to solve world hunger if they can’t communicate very well with users. An expert business analyst might be great at gathering requirements so the entire team can understand them, but if it means building 100% custom solutions because they don’t fit inside the SharePoint boundaries isn’t of much value. Just repeat. There is no silver bullet. There is no silver bullet. There is no silver bullet. A few people pointed out Nick Inglis’ article Excluding The Information Professional In SharePoint. It’s a good read too and hits home that maybe some developers and IT pros need some extra help in the information space. If you’re in an organization that needs labels on people, come up with something everyone understands and go with it. If that’s Business Solutions Architect, SharePoint Advisor, or Guy Who Knows A Lot About Portals, make it work for you. We all wish that one person could master all that is SharePoint but we also know that doesn’t scale very well and you quickly get into the hit-by-a-bus syndrome (with the organization coming to a full crawl when the guy or girl goes on vacation, gets sick, or pops out a baby). There are too many gaps in SharePoint knowledge to have any one person know it all and too many kittens to juggle all at once. We like to consider ourselves experts in our field, but trying to tackle too many roles at once and we end up being mediocre jack of all trades, master of none. Don't fall into this pit. It's a deep, dark hole you don't want to try to claw your way out of. Trust me. Been there. Done that. Got the t-shirt. In the end I don’t disagree with Joel. SharePoint is a beast and not something that should be taken on by newbies. If you just read “Teach Yourself SharePoint in 24 Hours” and want to go build your corporate intranet or the next killer business solution with all your new found knowledge plan to pony up consultant dollars a few months later when everything goes to Hell in a handbasket and falls over. I’m not saying don’t build solutions in SharePoint. I’m just saying that building effective ones takes skill like any craft and not something you can just cobble together with a little bit of cursory knowledge. Thanks to *everyone* who participated in this tweet rush. It was fun and educational.

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• Underwriting in a New Frontier: Spurring Innovation

  - by [email protected]

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* 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";} Susan Keuer, product strategy manager for Oracle Insurance, shares her experiences and insight from the 2010 Association of Home Office Underwriters (AHOU) Annual Conference, April 11-14, in San Antonio, Texas    How can I be more innovative in underwriting?  It's a common question I hear from insurance carriers, producers and others, so it was no surprise that it was the key theme at the recent 2010 AHOU Annual Conference.  This year's event drew more than 900 insurance professionals involved in the underwriting process across life and annuities, property and casualty and reinsurance from around the globe, including the U.S., Canada, Australia, Bahamas, and more, to San Antonio - a Texas city where innovation transformed a series of downtown drainage canals into its premiere River Walk tourist destination.   CNN's Medical Correspondent Dr. Sanjay Gupta kicked off the conference with a phenomenal opening session that drove home the theme of the conference, "Underwriting in a New Frontier:  Spurring Innovation."   Drawing from his own experience as a neurosurgeon treating critically injured medical patients in the field in Iraq, Gupta inspired audience members to think outside the box during the underwriting process. He shared a compelling story of operating on a soldier who had suffered a head-related trauma in a field hospital.  With minimal supplies available Gupta used a Black and Decker saw to operate on the soldier's head and reduce pressure on his swelling brain. Drawing from this example, Gupta encouraged underwriters to think creatively, be innovative, and consider new tools and sources of information, such as social networking sites, during the underwriting process. So as you are looking at risk take into consideration all resources you have available.    Gupta also stressed the concept of IKIGAI - noting that individuals who believe that their life is worth living are less likely to die than are their counterparts without this belief.  How does one quantify this approach to life or thought process when evaluating risk?  Could this be something to consider as a "category" in the near future? How can this same belief in your own work spur innovation?   The role of technology was a hot topic of discussion throughout the conference.  Sessions delved into the latest in underwriting software to the rise of social media and how it is being increasingly integrated into underwriting process and solutions.  In one session a trio of panelists representing the carrier, producer and vendor communities stressed the importance to underwriters of leveraging new technology and the plethora of online information sources, which all could be used to accurately, honestly and consistently evaluate the risk throughout the underwriting process.   Another focused on the explosion of social media noting:  1.    Social media is growing exponentially - About eight percent of Americans used social media five years ago. Today about 46 percent of Americans do so, with 85 percent of financial services professionals using social media in their work.  2.    It will impact your business - Underwriters reconfirmed over and over that they are increasingly using "free" tools that are available in cyberspace in lieu of more costly solutions, such as inspection reports conducted by individuals in the field.  3.    Information is instantly available on the Web, anytime, anywhere - LinkedIn was mentioned as a way to connect to peers in the underwriting community and producers alike.  Many carriers and agents also are using Facebook to promote their company to customers - and as a point-of-entry to allow them to perform some functionality - such as accessing product marketing information versus directing users to go to the carrier's own proprietary website.  Other carriers have released their tight brand marketing to allow their producers to drive more business to their personal Facebook site where they offer innovative tools such as Application Capture or asking medical information in a more relaxed fashion.     Other key topics at the conference included the economy, ongoing industry consolidation, real-estate valuations as an asset and input into the underwriting process, and producer trends.  All stressed a "back to basics" approach for low cost, term products.   Finally, Connie Merritt, RN, PHN, entertained the large group of atttendees with audience-engaging insight on how to "Tame the Lions in Your Life - Dealing with Complainers, Bullies, Grump and Curmudgeon." Merritt noted "we are too busy for our own good." She shared how her overachieving personality had impacted her life.  Audience members then were asked to pick red, yellow, blue, or green shapes, without knowing that each one represented a specific personality trait.  For example, those who picked blue were the peacemakers. Those who choose yellow were social - the hint was to "Be Quiet Longer."  She then offered these "lion taming" steps:   1.    Admit It 2.    Accept It 3.    Let Go 4.    Be Present (which paralleled Gupta's IKIGAI concept)   When thinking about underwriting I encourage you to be present in the moment and think creatively, but don't be afraid to look ahead to the future and be an innovator.  I hope to see you at next year's AHOU Annual Conference, May 1-4, 2011 at The Mirage in Las Vegas, Nev.     Susan Keuer is the product strategy manager for new business underwriting.  She brings more than 20 years of insurance industry experience working with leading insurance carriers and technology companies to her role on the product strategy team for life/annuities solutions within the Oracle Insurance Global Business Unit  

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• DBCC CHECKDB on VVLDB and latches (Or: My Pain is Your Gain)

  - by Argenis

    Does your CHECKDB hurt, Argenis? There is a classic blog series by Paul Randal [blog|twitter] called “CHECKDB From Every Angle” which is pretty much mandatory reading for anybody who’s even remotely considering going for the MCM certification, or its replacement (the Microsoft Certified Solutions Master: Data Platform – makes my fingers hurt just from typing it). Of particular interest is the post “Consistency Options for a VLDB” – on it, Paul provides solid, timeless advice (I use the word “timeless” because it was written in 2007, and it all applies today!) on how to perform checks on very large databases. Well, here I was trying to figure out how to make CHECKDB run faster on a restored copy of one of our databases, which happens to exceed 7TB in size. The whole thing was taking several days on multiple systems, regardless of the storage used – SAS, SATA or even SSD…and I actually didn’t pay much attention to how long it was taking, or even bothered to look at the reasons why - as long as it was finishing okay and found no consistency errors. Yes – I know. That was a huge mistake, as corruption found in a database several days after taking place could only allow for further spread of the corruption – and potentially large data loss. In the last two weeks I increased my attention towards this problem, as we noticed that CHECKDB was taking EVEN LONGER on brand new all-flash storage in the SAN! I couldn’t really explain it, and were almost ready to blame the storage vendor. The vendor told us that they could initially see the server driving decent I/O – around 450Mb/sec, and then it would settle at a very slow rate of 10Mb/sec or so. “Hum”, I thought – “CHECKDB is just not pushing the I/O subsystem hard enough”. Perfmon confirmed the vendor’s observations. Dreaded @BlobEater What was CHECKDB doing all the time while doing so little I/O? Eating Blobs. It turns out that CHECKDB was taking an extremely long time on one of our frankentables, which happens to be have 35 billion rows (yup, with a b) and sucks up several terabytes of space in the database. We do have a project ongoing to purge/split/partition this table, so it’s just a matter of time before we deal with it. But the reality today is that CHECKDB is coming to a screeching halt in performance when dealing with this particular table. Checking sys.dm_os_waiting_tasks and sys.dm_os_latch_stats showed that LATCH_EX (DBCC_OBJECT_METADATA) was by far the top wait type. I remembered hearing recently about that wait from another post that Paul Randal made, but that was related to computed-column indexes, and in fact, Paul himself reminded me of his article via twitter. But alas, our pathologic table had no non-clustered indexes on computed columns. I knew that latches are used by the database engine to do internal synchronization – but how could I help speed this up? After all, this is stuff that doesn’t have a lot of knobs to tweak. (There’s a fantastic level 500 talk by Bob Ward from Microsoft CSS [blog|twitter] called “Inside SQL Server Latches” given at PASS 2010 – and you can check it out here. DISCLAIMER: I assume no responsibility for any brain melting that might ensue from watching Bob’s talk!) Failed Hypotheses Earlier on this week I flew down to Palo Alto, CA, to visit our Headquarters – and after having a great time with my Monkey peers, I was relaxing on the plane back to Seattle watching a great talk by SQL Server MVP and fellow MCM Maciej Pilecki [twitter] called “Masterclass: A Day in the Life of a Database Transaction” where he discusses many different topics related to transaction management inside SQL Server. Very good stuff, and when I got home it was a little late – that slow DBCC CHECKDB that I had been dealing with was way in the back of my head. As I was looking at the problem at hand earlier on this week, I thought “How about I set the database to read-only?” I remembered one of the things Maciej had (jokingly) said in his talk: “if you don’t want locking and blocking, set the database to read-only” (or something to that effect, pardon my loose memory). I immediately killed the CHECKDB which had been running painfully for days, and set the database to read-only mode. Then I ran DBCC CHECKDB against it. It started going really fast (even a bit faster than before), and then throttled down again to around 10Mb/sec. All sorts of expletives went through my head at the time. Sure enough, the same latching scenario was present. Oh well. I even spent some time trying to figure out if NUMA was hurting performance. Folks on Twitter made suggestions in this regard (thanks, Lonny! [twitter]) …Eureka? This past Friday I was still scratching my head about the whole thing; I was ready to start profiling with XPERF to see if I could figure out which part of the engine was to blame and then get Microsoft to look at the evidence. After getting a bunch of good news I’ll blog about separately, I sat down for a figurative smack down with CHECKDB before the weekend. And then the light bulb went on. A sparse column. I thought that I couldn’t possibly be experiencing the same scenario that Paul blogged about back in March showing extreme latching with non-clustered indexes on computed columns. Did I even have a non-clustered index on my sparse column? As it turns out, I did. I had one filtered non-clustered index – with the sparse column as the index key (and only column). To prove that this was the problem, I went and setup a test. Yup, that'll do it The repro is very simple for this issue: I tested it on the latest public builds of SQL Server 2008 R2 SP2 (CU6) and SQL Server 2012 SP1 (CU4). First, create a test database and a test table, which only needs to contain a sparse column: CREATE DATABASE SparseColTest; GO USE SparseColTest; GO CREATE TABLE testTable (testCol smalldatetime SPARSE NULL); GO INSERT INTO testTable (testCol) VALUES (NULL); GO 1000000 That’s 1 million rows, and even though you’re inserting NULLs, that’s going to take a while. In my laptop, it took 3 minutes and 31 seconds. Next, we run DBCC CHECKDB against the database: DBCC CHECKDB('SparseColTest') WITH NO_INFOMSGS, ALL_ERRORMSGS; This runs extremely fast, as least on my test rig – 198 milliseconds. Now let’s create a filtered non-clustered index on the sparse column: CREATE NONCLUSTERED INDEX [badBadIndex] ON testTable (testCol) WHERE testCol IS NOT NULL; With the index in place now, let’s run DBCC CHECKDB one more time: DBCC CHECKDB('SparseColTest') WITH NO_INFOMSGS, ALL_ERRORMSGS; In my test system this statement completed in 11433 milliseconds. 11.43 full seconds. Quite the jump from 198 milliseconds. I went ahead and dropped the filtered non-clustered indexes on the restored copy of our production database, and ran CHECKDB against that. We went down from 7+ days to 19 hours and 20 minutes. Cue the “Argenis is not impressed” meme, please, Mr. LaRock. My pain is your gain, folks. Go check to see if you have any of such indexes – they’re likely causing your consistency checks to run very, very slow. Happy CHECKDBing, -Argenis ps: I plan to file a Connect item for this issue – I consider it a pretty serious bug in the engine. After all, filtered indexes were invented BECAUSE of the sparse column feature – and it makes a lot of sense to use them together. Watch this space and my twitter timeline for a link.

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