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• script to count the occurence of the particular string in the given time interval

  - by pruthvi

  We are trying to write a script "sendemail.sh" to count the number of occurrence of a particular string in a log file "SendEmail.log" within the given interval. We have a log file. In that we are searching for a pattern "ReqInputMsgLog" and need to count the number of times it occurred in the given period for eg: from "2014-08-19 11:30" to "2014-08-19 11:34". And our script look like this: #!/bin/sh enterdate=$1 echo $enterdate enddate=$2 enterdate1=`date +%s -d $enterdate +"%Y-%m-%d %H:%M"` echo $enterdate1 enddate1=`date +%s -d $enddate +"%Y-%m-%d %H:%M"` echo $enddate count=0 cat SendEmail.log | grep "ReqInputMsgLog" | awk -F "[" '{print $3}' | awk -F "," '{print $1}' > /con/scripts_server/file.txt for line in `cat /con/scripts_server/file.txt` do logdate=`echo $line | awk -F : '{print $1":"$2}'` if [[ $logdate < $enddate1 ]]; then count=`expr $count + 1` fi done echo $count But when we are trying to execute the script by the below command its not showing the proper count. ./sendemail.sh "2014-08-19 11:30" "2014-08-19 11:34" Log file is very big one. Small chunk has been posted here. INFO [SIBJMSRAThreadPool : 5] [2014-08-19 11:18:24,471] SendEmail - 8/19/14 11:18 AM,ECCF25B0-0147-4000-E000-1B830A3C05A9,ReqInputMsgLog,SendEmail,<?xml version="1.0" encoding="UTF-8"?> <in:sendEmailRequestMsg xmlns:in="http://EmailMed/EmailMedInterface" xmlns:ns0="wsdl.http://EmailMed/EmailMedInterface" xmlns:ns1="http://EmailMed/EmailMedInterface" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:me="wsdl.http://EmailMed/EmailMedInterface" xsi:type="me:sendEmailRequestMsg"> <in:sendEmail xmlns:xci0="http://EmailMed/EmailMedInterface"> INFO [SIBJMSRAThreadPool : 7] [2014-08-19 11:18:14,235] SendEmail - 8/19/14 11:18 AM,ECCEFDB2-0147-4000-E000-1B830A3C05A9,ReqInputMsgLog,SendEmail,<?xml version="1.0" encoding="UTF-8"?> <in:sendEmailRequestMsg xmlns:in="http://EmailMed/EmailMedInterface" xmlns:ns0="wsdl.http://EmailMed/EmailMedInterface" xmlns:ns1="http://EmailMed/EmailMedInterface" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:me="wsdl.http://EmailMed/EmailMedInterface" xsi:type="me:sendEmailRequestMsg"> <in:sendEmail xmlns:xci0="http://EmailMed/EmailMedInterface"> INFO [SIBJMSRAThreadPool : 7] [2014-08-19 11:18:14,241] SendEmail - xmlText: <?xml version="1.0" encoding="UTF-8"?> after awk command we will get a file "/con/scripts_server/file.txt" which looks similar like below: 2014-08-19 11:28:03 2014-08-19 11:28:06 2014-08-19 11:28:17 2014-08-19 11:28:53 2014-08-19 11:29:02 2014-08-19 11:29:47 2014-08-19 11:29:57 2014-08-19 11:30:07 2014-08-19 11:30:17 2014-08-19 11:30:19 2014-08-19 11:30:19 2014-08-19 11:30:22 2014-08-19 11:30:25 2014-08-19 11:30:25 2014-08-19 11:30:36 2014-08-19 11:30:51 2014-08-19 11:30:56 2014-08-19 11:30:59 2014-08-19 11:30:59 2014-08-19 11:31:08 2014-08-19 11:31:25 2014-08-19 11:32:19 2014-08-19 11:32:22 2014-08-19 11:32:27 2014-08-19 11:32:28 2014-08-19 11:32:41 2014-08-19 11:32:49 2014-08-19 11:32:59 2014-08-19 11:33:27 2014-08-19 11:33:41 2014-08-19 11:34:07 2014-08-19 11:34:14 2014-08-19 11:34:21 2014-08-19 11:34:25 2014-08-19 11:34:38 2014-08-19 11:34:50 2014-08-19 11:34:58

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• nginx rewrite for /blah/(.*) /$1

  - by skrewler

  I'm migrating from mod_php to nginx. I got everything working except for this rewrite.. I'm just not familiar enough with nginx configuration to know the correct way to do this. I came up with this by looking at a sample on the nginx site. server { server_name test01.www.myhost.com; root /home/vhosts/my_home/blah; access_log /var/log/nginx/blah.access.log; error_log /var/log/nginx/blah.error.log; index index.php; location / { try_files $uri $uri/ @rewrites; } location @rewrites { rewrite ^ /index.php last; rewrite ^/ht/userGreeting.php /js/iFrame/index.php last; rewrite ^/ht/(.*)$ /$1 last; rewrite ^/userGreeting.php$ /js/iFrame/index.php last; rewrite ^/a$ /adminLogin.php last; rewrite ^/boom\/(.*)$ /boom/index.php?q=$1 last; rewrite ^favicon.ico$ favico_ry.ico last; } # This block will catch static file requests, such as images, css, js # The ?: prefix is a 'non-capturing' mark, meaning we do not require # the pattern to be captured into $1 which should help improve performance location ~* \.(?:ico|css|js|gif|jpe?g|png)$ { # Some basic cache-control for static files to be sent to the browser expires max; add_header Pragma public; add_header Cache-Control "public, must-revalidate, proxy-revalidate"; } include php.conf; } The issue I'm having is with this rewrite: rewrite ^ht\/(.*)$ /$1 last; 99% of requests that will hit this rewrite are static files. So I think maybe it's getting sent to the static files section and that's where things are being messed up? I tried adding this but it didn't work: location ~* ^ht\/.*\.(?:ico|css|js|gif|jpe?g|png)$ { # Some basic cache-control for static files to be sent to the browser expires max; add_header Pragma public; add_header Cache-Control "public, must-revalidate, proxy-revalidate"; } Any help would be appreciated. I know the best thing to do would be to just change the references of /ht/whatever.jpg to /whatever.jpg in the code.. but that's not an option for now.

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• MongoDB and datasets that don't fit in RAM no matter how hard you shove

  - by sysadmin1138

  This is very system dependent, but chances are near certain we'll scale past some arbitrary cliff and get into Real Trouble. I'm curious what kind of rules-of-thumb exist for a good RAM to Disk-space ratio. We're planning our next round of systems, and need to make some choices regarding RAM, SSDs, and how much of each the new nodes will get. But now for some performance details! During normal workflow of a single project-run, MongoDB is hit with a very high percentage of writes (70-80%). Once the second stage of the processing pipeline hits, it's extremely high read as it needs to deduplicate records identified in the first half of processing. This is the workflow for which "keep your working set in RAM" is made for, and we're designing around that assumption. The entire dataset is continually hit with random queries from end-user derived sources; though the frequency is irregular, the size is usually pretty small (groups of 10 documents). Since this is user-facing, the replies need to be under the "bored-now" threshold of 3 seconds. This access pattern is much less likely to be in cache, so will be very likely to incur disk hits. A secondary processing workflow is high read of previous processing runs that may be days, weeks, or even months old, and is run infrequently but still needs to be zippy. Up to 100% of the documents in the previous processing run will be accessed. No amount of cache-warming can help with this, I suspect. Finished document sizes vary widely, but the median size is about 8K. The high-read portion of the normal project processing strongly suggests the use of Replicas to help distribute the Read traffic. I have read elsewhere that a 1:10 RAM-GB to HD-GB is a good rule-of-thumb for slow disks, As we are seriously considering using much faster SSDs, I'd like to know if there is a similar rule of thumb for fast disks. I know we're using Mongo in a way where cache-everything really isn't going to fly, which is why I'm looking at ways to engineer a system that can survive such usage. The entire dataset will likely be most of a TB within half a year and keep growing.

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• Windows 2003 Server Caching

  - by pablomedok

  We're experiencing almost everyday table index corruption on Windows Server 2003. We are running an old application which uses DBF/CDX tables. Everything was fine for ages, but 6 months after we've installed Advantage Database Server (which allows access to some tables to our website) we started to get index corruption problems. And we don't know whom to blame. We've tried to exclude all possible causes of this corruption. Now all users work in terminal mode - so no network problems can cause that, OpLocks also can't be a reason. We changed hardware, network cards, switches, reainstalled Server and even moved to new dedicated server. The only thing we can't exclude is ADS - because it should be working. Is that possible that local read/write caching that causes that problem? E.g. one user or process uses cached data, later another user/process changes it, and later the first user changes it again without knowing about the first change. Is it possible theoretically? Is it possible that this problem is caused by imporper file server or caching settings? Is it possible that normal users use non-cached data and ADS is using cached data? Or vice versa? Is it possible that each terminal user has its own cache? Or maybe the problem is about RAID caching somehow interfering with Windows Server caching? Or maybe there are some special settings for Windows Server for working with DBF tables that are being written simultaneously by several terminal users? Maybe there is a way to turn off caching for some certain files to check it? Sometimes we get index crash twice a day, sometimes everything is fine for 5 days in a row. Today only one user was working in the evening with the database (usually there are 30-50 users are working simultaneously on working hours). So it's almost zero load on server. , Syncronization with website is performed every 5 minutes during work hours and every 15 minutes in the evening and on weekend. We've done file access auditing and it shows that during website syncroniztions ADS server opens the table and index files for ReadEA and WriteEA though it performs only SELECT queries. ADS does UPDATE/INSERT queries but less freqently - not during regular synchronizations, but only when an order is placed by website visitor). Please help me. We are struggling with this problem for almost a year and still can't find any pattern or any clue about this problem. Here is my previous qestion about this issue on DBA: http://dba.stackexchange.com/questions/8646/foxpro-dbf-index-corruption

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• Asterisk: Dropping calls with an "ast_yyerror"

  - by Nick

  I'm having an intermittent issue where asterisk will play our greeting to the caller, and then drop the call instead of making our phones ring. I'm unable to reproduce the problem with any phones I have here, and many callers get through just fine. Some callers though, run into the problem, and I can't find any pattern to it. The bit of information I could find said it was caused by an error in evaluating a dialplan expression. I'm thinking it's this line: exten = START,n,GotoIf($[${FORCE_CLOSED}=TRUE]?CLOSED,1) But I'm not sure what's wrong with it. I see the following error on the console: [Apr 4 16:29:49] WARNING[27038]: ast_expr2.fl:459 ast_yyerror: ast_yyerror(): syntax error: syntax error, unexpected '=', expecting $end; Input:=TRUE^ Surrounding Console output: -- Executing [START@AGInbound:1] Answer("IAX2/AtlantaTeliax-10086", "") in new stack -- Executing [START@AGInbound:2] BackGround("IAX2/AtlantaTeliax-10086", 0000_AG_THANK_YOU_FOR_CALLING_AG") in new stack -- Playing '0000_AG_THANK_YOU_FOR_CALLING_AG.slin' (language 'en') [Apr 4 16:29:49] WARNING[27038]: ast_expr2.fl:459 ast_yyerror: ast_yyerror(): syntax error: syntax error, unexpected '=', expecting $end; Input: =TRUE ^ [Apr 4 16:29:49] WARNING[27038]: ast_expr2.fl:463 ast_yyerror: If you have questions, please refer to doc/tex/channelvariables.tex in the asterisk source. -- Executing [START@AGInbound:3] GotoIf("IAX2/AtlantaTeliax-10086", "?CLOSED,1") in new stack -- Executing [START@AGInbound:4] GotoIfTime("IAX2/AtlantaTeliax-10086", "9:30-17:0|mon-fri|*|*?OPEN,1") in new stack -- Executing [START@AGInbound:5] GotoIfTime("IAX2/AtlantaTeliax-10086", "10:0-18:30|sat|*|*?OPEN,1") in new stack -- Executing [START@AGInbound:6] GotoIfTime("IAX2/AtlantaTeliax-10086", "12:0-17:0|sun|*|*?OPEN,1") in new stack Relevant lines from the dial plan: exten = START,1,Answer() exten = START,n,Background(0000_AG_THANK_YOU_FOR_CALLING_AG) ; See if we're open ; Force Closed if no one's going to be answering exten = START,n,GotoIf($[${FORCE_CLOSED}=TRUE]?CLOSED,1) exten = START,n,GotoIfTime(${AG_WEEKDAY_OPEN_HOUR}:${AG_WEEKDAY_OPEN_MIN}-${AG$ exten = START,n,GotoIfTime(${AG_SATURDAY_OPEN_HOUR}:${AG_SATURDAY_OPEN_MIN}-${$ exten = START,n,GotoIfTime(${AG_SUNDAY_OPEN_HOUR}:${AG_SUNDAY_OPEN_MIN}-${AG_S$ ; ...and we're not. But maybe the time of day has been overridden? exten = START,n,GotoIf($[${OVERRIDE_TIME_OF_DAY}=TRUE]?OPEN,1) ; No override... We're definatly closed. exten = START,n,Goto(CLOSED,1) Any idea what's wrong with the expression? We recently upgraded from 1.4 to 1.6.

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• How to loop through all illustrator files in a folder (CS6)

  - by Julian

  I have written some JavaScript to save .ai files to two separate locations with different resolutions, one of them being cropped to a reduced size art board. (Courtesy of John Otterud / Articmill for the main part). There are other variables in the script that I am not using at present but I want to leave the functionality there for a later date/additional layers to export/other resolutions etc. I can't get it to loop through all files in a folder. I cannot find the script that works - or insert it at the right place. I can get as far a selecting the folder and I suppose creating an array but after that what next? This is the create array part of the script - // JavaScript Document //Set up vairaibles var destDoc, sourceDoc, sourceFolder, newLayer; // Select the source folder. sourceFolder = Folder.selectDialog('Select the folder with Illustrator files that you want to mere into one', '~'); destDoc = app.documents.add(); // If a valid folder is selected if (sourceFolder != null) { files = new Array(); // Get all files matching the pattern files = sourceFolder.getFiles(); I have inserted this at the beginning of the main script (probably where I am going wrong because I can select the folder but then nothing more) #target illustrator var docRef = app.activeDocument; with (docRef) { if (layers[i].name = 'HEADER') { layers[i].name = '#'+ activeDocument.name; save() } } // *** Export Layers as PNG files (in multiple resolutions) *** var subFolderName = "For_PLMA"; var subFolderTwoName = "For_VLP"; var saveInMultipleResolutions = true; // ... // Note: only use one character! var exportLayersStartingWith = "%"; var exportLayersWithArtboardClippingStartingWith = "#"; // ... var normalResolutionFileAppend = "_VLP"; var highResolutionFileAppend = "_PLMA"; // ... var normalResolutionScale = 100; var highResolutionScale = 200; var veryhighResolutionScale = 300; // *** Start of script *** var doc = app.activeDocument; // Make sure we have saved the document if (doc.path != "") { Then the rest of the export script runs on from there.

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• Ask How-To Geek: Learning the Office Ribbon, Booting to USB with an Old BIOS, and Snapping Windows

  - by Jason Fitzpatrick

  You’ve got questions and we’ve got answers. Today we highlight how to master the new Office interface, USB boot a computer with outdated BIOS, and snap windows to preset locations. Learning the New Office Ribbon Dear How-To Geek, I feel silly asking this (in light of how long the new Office interface has been out) but my company finally got around to upgrading from Windows XP and Office 2000 so the new interface it totally new to me. Can you recommend any resources for quickly learning the Office ribbon and the new changes? I feel completely lost after two decades of the old Office interface. Help! Sincerely, Where the Hell is Everything? Dear Where the Hell, We think most people were with you at some point in the last few years. “Where the hell is…” could possibly be the slogan for the new ribbon interface. You could browse through some of the dry tutorials online or even get a weighty book on the topic but the best way to learn something new is to get hands on. Ribbon Hero turns learning the new Office features and ribbon layout into a game. It’s no vigorous round of Team Fortress mind you, but it’s significantly more fun than reading a training document. Check out how to install and configure Ribbon Hero here. You’ll be teaching your coworkers new tricks in no time. Boot via USB with an Old BIOS Dear How-To Geek, I’m trying to repurpose some old computers by updating them with lightweight Linux distros but the BIOS on most of the machines is ancient and creaky. How ancient? It doesn’t even support booting from a USB device! I have a large flash drive that I’ve turned into a master installation tool for jobs like this but I can’t use it. The computers in question have USB ports; they just aren’t recognized during the boot process. What can I do? USB Bootin’ in Boise Dear USB Bootin’, It’s great you’re working to breathe life into old hardware! You’ve run into one of the limitations of older BIOSes, USB was around but nobody was thinking about booting off of it. Fortunately if you have a computer old enough to have that kind of BIOS it’s likely to also has a floppy drive or a CDROM drive. While you could make a bootable CDROM for your application we understand that you want to keep using the master USB installer you’ve made. In light of that we recommend PLoP Boot Manager. Think of it like a boot manager for your boot manager. Using it you can create a bootable floppy or CDROM that will enable USB booting of your master USB drive. Make a CD and a floppy version and you’ll have everything in your toolkit you need for future computer refurbishing projects. Read up on creating bootable media with PLoP Boot Manager here. Snapping Windows to Preset Coordinates Dear How-To Geek, Once upon a time I had a company laptop that came with a little utility that snapped windows to preset areas of the screen. This was long before the snap-to-side features in Windows 7. You could essentially configure your screen into a grid pattern of your choosing and then windows would neatly snap into those grids. I have no idea what it was called or if was anymore than a gimmick from the computer manufacturer, but I’d really like to have it on my new computer! Bend and Snap in San Francisco, Dear Bend and Snap, If we had to guess, we’d guess your company must have had a set of laptops from Acer as the program you’re describing sounds exactly like Acer GridVista. Fortunately for you the application was extremely popular and Acer released it independently of their hardware. If, by chance, you’ve since upgraded to a multiple monitor setup the app even supports multiple monitors—many of the configurations are handy for arranging IM windows and other auxiliary communication tools. Check out our guide to installing and configuring Acer GridVista here for more information. Have a question you want to put before the How-To Geek staff? Shoot us an email at [email protected] and then keep an eye out for a solution in the Ask How-To Geek column. Latest Features How-To Geek ETC How to Upgrade Windows 7 Easily (And Understand Whether You Should) The How-To Geek Guide to Audio Editing: Basic Noise Removal Install a Wii Game Loader for Easy Backups and Fast Load Times The Best of CES (Consumer Electronics Show) in 2011 The Worst of CES (Consumer Electronics Show) in 2011 HTG Projects: How to Create Your Own Custom Papercraft Toy Download the New Year in Japan Windows 7 Theme from Microsoft Once More Unto the Breach – Facebook Apps Can Now Access Your Address and Phone Number Dial Zero Speeds You Through Annoying Customer Service Menus Complete Dropquest 2011 and Receive Free Dropbox Storage Desktop Computer versus Laptop Wallpaper The Kids Have No Idea What Old Tech Is [Video]

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• Using Unity – Part 3

  - by nmarun

  The previous blog was about registering and invoking different types dynamically. In this one I’d like to show how Unity manages/disposes the instances – say hello to Lifetime Managers. When a type gets registered, either through the config file or when RegisterType method is explicitly called, the default behavior is that the container uses a transient lifetime manager. In other words, the unity container creates a new instance of the type when Resolve or ResolveAll method is called. Whereas, when you register an existing object using the RegisterInstance method, the container uses a container controlled lifetime manager - a singleton pattern. It does this by storing the reference of the object and that means so as long as the container is ‘alive’, your registered instance does not go out of scope and will be disposed only after the container either goes out of scope or when the code explicitly disposes the container. Let’s see how we can use these and test if something is a singleton or a transient instance. Continuing on the same solution used in the previous blogs, I have made the following changes: First is to add typeAlias elements for TransientLifetimeManager type: 1: <typeAlias alias="transient" type="Microsoft.Practices.Unity.TransientLifetimeManager, Microsoft.Practices.Unity"/> You then need to tell what type(s) you want to be transient by nature: 1: <type type="IProduct" mapTo="Product2"> 2: <lifetime type="transient" /> 3: </type> 4: <!--<type type="IProduct" mapTo="Product2" />--> The lifetime element’s type attribute matches with the alias attribute of the typeAlias element. Now since ‘transient’ is the default behavior, you can have a concise version of the same as line 4 shows. Also note that I’ve changed the mapTo attribute from ‘Product’ to ‘Product2’. I’ve done this to help understand the transient nature of the instance of the type Product2. By making this change, you are basically saying when a type of IProduct needs to be resolved, Unity should create an instance of Product2 by default. 1: public string WriteProductDetails() 2: { 3: return string.Format("Name: {0}<br/>Category: {1}<br/>Mfg Date: {2}<br/>Hash Code: {3}", 4: Name, Category, MfgDate.ToString("MM/dd/yyyy hh:mm:ss tt"), GetHashCode()); 5: } Again, the above change is purely for the purpose of making the example more clear to understand. The display will show the full date and also displays the hash code of the current instance. The GetHashCode() method returns an integer when an instance gets created – a new integer for every instance. When you run the application, you’ll see something like the below: Now when you click on the ‘Get Product2 Instance’ button, you’ll see that the Mfg Date (which is set in the constructor) and the Hash Code are different from the one created on page load. This proves to us that a new instance is created every single time. To make this a singleton, we need to add a type alias for the ContainerControlledLifetimeManager class and then change the type attribute of the lifetime element to singleton. 1: <typeAlias alias="singleton" type="Microsoft.Practices.Unity.ContainerControlledLifetimeManager, Microsoft.Practices.Unity"/> 2: ... 3: <type type="IProduct" mapTo="Product2"> 4: <lifetime type="singleton" /> 5: </type> Running the application now gets me the following output: Click on the button below and you’ll see that the Mfg Date and the Hash code remain unchanged => the unity container is storing the reference the first time it is created and then returns the same instance every time the type needs to be resolved. Digging more deeper into this, Unity provides more than the two lifetime managers. ExternallyControlledLifetimeManager – maintains a weak reference to type mappings and instances. Unity returns the same instance as long as the some code is holding a strong reference to this instance. For this, you need: 1: <typeAlias alias="external" type="Microsoft.Practices.Unity.ExternallyControlledLifetimeManager, Microsoft.Practices.Unity"/> 2: ... 3: <type type="IProduct" mapTo="Product2"> 4: <lifetime type="external" /> 5: </type> PerThreadLifetimeManager – Unity returns a unique instance of an object for each thread – so this effectively is a singleton behavior on a  per-thread basis. 1: <typeAlias alias="perThread" type="Microsoft.Practices.Unity.PerThreadLifetimeManager, Microsoft.Practices.Unity"/> 2: ... 3: <type type="IProduct" mapTo="Product2"> 4: <lifetime type="perThread" /> 5: </type> One thing to note about this is that if you use RegisterInstance method to register an existing object, this instance will be returned for every thread, making this a purely singleton behavior. Needless to say, this type of lifetime management is useful in multi-threaded applications (duh!!). I hope this blog provided some basics on lifetime management of objects resolved in Unity and in the next blog, I’ll talk about Injection. Please see the code used here.

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• Parallelism in .NET – Part 12, More on Task Decomposition

  - by Reed

  Many tasks can be decomposed using a Data Decomposition approach, but often, this is not appropriate.  Frequently, decomposing the problem into distinctive tasks that must be performed is a more natural abstraction. However, as I mentioned in Part 1, Task Decomposition tends to be a bit more difficult than data decomposition, and can require a bit more effort.  Before we being parallelizing our algorithm based on the tasks being performed, we need to decompose our problem, and take special care of certain considerations such as ordering and grouping of tasks. Up to this point in this series, I’ve focused on parallelization techniques which are most appropriate when a problem space can be decomposed by data.  Using PLINQ and the Parallel class, I’ve shown how problem spaces where there is a collection of data, and each element needs to be processed, can potentially be parallelized. However, there are many other routines where this is not appropriate.  Often, instead of working on a collection of data, there is a single piece of data which must be processed using an algorithm or series of algorithms.  Here, there is no collection of data, but there may still be opportunities for parallelism. As I mentioned before, in cases like this, the approach is to look at your overall routine, and decompose your problem space based on tasks.  The idea here is to look for discrete “tasks,” individual pieces of work which can be conceptually thought of as a single operation. Let’s revisit the example I used in Part 1, an application startup path.  Say we want our program, at startup, to do a bunch of individual actions, or “tasks”.  The following is our list of duties we must perform right at startup: Display a splash screen Request a license from our license manager Check for an update to the software from our web server If an update is available, download it Setup our menu structure based on our current license Open and display our main, welcome Window Hide the splash screen The first step in Task Decomposition is breaking up the problem space into discrete tasks. This, naturally, can be abstracted as seven discrete tasks.  In the serial version of our program, if we were to diagram this, the general process would appear as: These tasks, obviously, provide some opportunities for parallelism.  Before we can parallelize this routine, we need to analyze these tasks, and find any dependencies between tasks.  In this case, our dependencies include: The splash screen must be displayed first, and as quickly as possible. We can’t download an update before we see whether one exists. Our menu structure depends on our license, so we must check for the license before setting up the menus. Since our welcome screen will notify the user of an update, we can’t show it until we’ve downloaded the update. Since our welcome screen includes menus that are customized based off the licensing, we can’t display it until we’ve received a license. We can’t hide the splash until our welcome screen is displayed. By listing our dependencies, we start to see the natural ordering that must occur for the tasks to be processed correctly. The second step in Task Decomposition is determining the dependencies between tasks, and ordering tasks based on their dependencies. Looking at these tasks, and looking at all the dependencies, we quickly see that even a simple decomposition such as this one can get quite complicated.  In order to simplify the problem of defining the dependencies, it’s often a useful practice to group our tasks into larger, discrete tasks.  The goal when grouping tasks is that you want to make each task “group” have as few dependencies as possible to other tasks or groups, and then work out the dependencies within that group.  Typically, this works best when any external dependency is based on the “last” task within the group when it’s ordered, although that is not a firm requirement.  This process is often called Grouping Tasks.  In our case, we can easily group together tasks, effectively turning this into four discrete task groups: 1. Show our splash screen – This needs to be left as its own task.  First, multiple things depend on this task, mainly because we want this to start before any other action, and start as quickly as possible. 2. Check for Update and Download the Update if it Exists - These two tasks logically group together.  We know we only download an update if the update exists, so that naturally follows.  This task has one dependency as an input, and other tasks only rely on the final task within this group. 3. Request a License, and then Setup the Menus – Here, we can group these two tasks together.  Although we mentioned that our welcome screen depends on the license returned, it also depends on setting up the menu, which is the final task here.  Setting up our menus cannot happen until after our license is requested.  By grouping these together, we further reduce our problem space. 4. Display welcome and hide splash - Finally, we can display our welcome window and hide our splash screen.  This task group depends on all three previous task groups – it cannot happen until all three of the previous groups have completed. By grouping the tasks together, we reduce our problem space, and can naturally see a pattern for how this process can be parallelized.  The diagram below shows one approach: The orange boxes show each task group, with each task represented within.  We can, now, effectively take these tasks, and run a large portion of this process in parallel, including the portions which may be the most time consuming.  We’ve now created two parallel paths which our process execution can follow, hopefully speeding up the application startup time dramatically. The main point to remember here is that, when decomposing your problem space by tasks, you need to: Define each discrete action as an individual Task Discover dependencies between your tasks Group tasks based on their dependencies Order the tasks and groups of tasks

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• Parallelism in .NET – Part 13, Introducing the Task class

  - by Reed

  Once we’ve used a task-based decomposition to decompose a problem, we need a clean abstraction usable to implement the resulting decomposition.  Given that task decomposition is founded upon defining discrete tasks, .NET 4 has introduced a new API for dealing with task related issues, the aptly named Task class. The Task class is a wrapper for a delegate representing a single, discrete task within your decomposition.  We will go into various methods of construction for tasks later, but, when reduced to its fundamentals, an instance of a Task is nothing more than a wrapper around a delegate with some utility functionality added.  In order to fully understand the Task class within the new Task Parallel Library, it is important to realize that a task really is just a delegate – nothing more.  In particular, note that I never mentioned threading or parallelism in my description of a Task.  Although the Task class exists in the new System.Threading.Tasks namespace: Tasks are not directly related to threads or multithreading. Of course, Task instances will typically be used in our implementation of concurrency within an application, but the Task class itself does not provide the concurrency used.  The Task API supports using Tasks in an entirely single threaded, synchronous manner. Tasks are very much like standard delegates.  You can execute a task synchronously via Task.RunSynchronously(), or you can use Task.Start() to schedule a task to run, typically asynchronously.  This is very similar to using delegate.Invoke to execute a delegate synchronously, or using delegate.BeginInvoke to execute it asynchronously. The Task class adds some nice functionality on top of a standard delegate which improves usability in both synchronous and multithreaded environments. The first addition provided by Task is a means of handling cancellation via the new unified cancellation mechanism of .NET 4.  If the wrapped delegate within a Task raises an OperationCanceledException during it’s operation, which is typically generated via calling ThrowIfCancellationRequested on a CancellationToken, or if the CancellationToken used to construct a Task instance is flagged as canceled, the Task’s IsCanceled property will be set to true automatically.  This provides a clean way to determine whether a Task has been canceled, often without requiring specific exception handling. Tasks also provide a clean API which can be used for waiting on a task.  Although the Task class explicitly implements IAsyncResult, Tasks provide a nicer usage model than the traditional .NET Asynchronous Programming Model.  Instead of needing to track an IAsyncResult handle, you can just directly call Task.Wait() to block until a Task has completed.  Overloads exist for providing a timeout, a CancellationToken, or both to prevent waiting indefinitely.  In addition, the Task class provides static methods for waiting on multiple tasks – Task.WaitAll and Task.WaitAny, again with overloads providing time out options.  This provides a very simple, clean API for waiting on single or multiple tasks. Finally, Tasks provide a much nicer model for Exception handling.  If the delegate wrapped within a Task raises an exception, the exception will automatically get wrapped into an AggregateException and exposed via the Task.Exception property.  This exception is stored with the Task directly, and does not tear down the application.  Later, when Task.Wait() (or Task.WaitAll or Task.WaitAny) is called on this task, an AggregateException will be raised at that point if any of the tasks raised an exception.  For example, suppose we have the following code: Task taskOne = new Task( () => { throw new ApplicationException("Random Exception!"); }); Task taskTwo = new Task( () => { throw new ArgumentException("Different exception here"); }); // Start the tasks taskOne.Start(); taskTwo.Start(); try { Task.WaitAll(new[] { taskOne, taskTwo }); } catch (AggregateException e) { Console.WriteLine(e.InnerExceptions.Count); foreach (var inner in e.InnerExceptions) Console.WriteLine(inner.Message); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Here, our routine will print: 2 Different exception here Random Exception! Note that we had two separate tasks, each of which raised two distinctly different types of exceptions.  We can handle this cleanly, with very little code, in a much nicer manner than the Asynchronous Programming API.  We no longer need to handle TargetInvocationException or worry about implementing the Event-based Asynchronous Pattern properly by setting the AsyncCompletedEventArgs.Error property.  Instead, we just raise our exception as normal, and handle AggregateException in a single location in our calling code.

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• Database model for keeping track of likes/shares/comments on blog posts over time

  - by gage

  My goal is to keep track of the popular posts on different blog sites based on social network activity at any given time. The goal is not to simply get the most popular now, but instead find posts that are popular compared to other posts on the same blog. For example, I follow a tech blog, a sports blog, and a gossip blog. The tech blog gets waaay more readership than the other two blogs, so in raw numbers every post on the tech blog will always out number views on the other two. So lets say the average tech blog post gets 500 facebook likes and the other two get an average of 50 likes per post. Then when there is a sports blog post that has 200 fb likes and a gossip blog post with 300 while the tech blog posts today have 500 likes I want to highlight the sports and gossip blog posts (more likes than average vs tech blog with more # of likes but just average for the blog) The approach I am thinking of taking is to make an entry in a database for each blog post. Every x minutes (say every 15 minutes) I will check how many likes/shares/comments an entry has received on all the social networks (facebook, twitter, google+, linkeIn). So over time there will be a history of likes for each blog post, i.e post 1234 after 15 min: 10 fb likes, 4 tweets, 6 g+ after 30 min: 15 fb likes, 15 tweets, 10 g+ ... ... after 48 hours: 200 fb likes, 25 tweets, 15 g+ By keeping a history like this for each blog post I can know the average number of likes/shares/tweets at any give time interval. So for example the average number of fb likes for all blog posts 48hrs after posting is 50, and a particular post has 200 I can mark that as a popular post and feature/highlight it. A consideration in the design is to be able to easily query the values (likes/shares) for a specific time-frame, i.e. fb likes after 30min or tweets after 24 hrs in-order to compute averages with which to compare against (or should averages be stored in it's own table?) If this approach is flawed or could use improvement please let me know, but it is not my main question. My main question is what should a database scheme for storing this info look like? Assuming that the above approach is taken I am trying to figure out what a database schema for storing the likes over time would look like. I am brand new to databases, in doing some basic reading I see that it is advisable to make a 3NF database. I have come up with the following possible schema. Schema 1 DB Popular Posts Table: Post post_id ( primary key(pk) ) url title Table: Social Activity activity_id (pk) url (fk) type (i.e. facebook,twitter,g+) value timestamp This was my initial instinct (base on my very limited db knowledge). As far as I under stand this schema would be 3NF? I searched for designs of similar database model, and found this question on stackoverflow, http://stackoverflow.com/questions/11216080/data-structure-for-storing-height-and-weight-etc-over-time-for-multiple-users . The scenario in that question is similar (recording weight/height of users overtime). Taking the accepted answer for that question and applying it to my model results in something like: Schema 2 (same as above, but break down the social activity into 2 tables) DB Popular Posts Table: Post post_id (pk) url title Table: Social Measurement measurement_id (pk) post_id (fk) timestamp Table: Social stat stat_id (pk) measurement_id (fk) type (i.e. facebook,twitter,g+) value The advantage I see in schema 2 is that I will likely want to access all the values for a given time, i.e. when making a measurement at 30min after a post is published I will simultaneous check number of fb likes, fb shares, fb comments, tweets, g+, linkedIn. So with this schema it may be easier get get all stats for a measurement_id corresponding to a certain time, i.e. all social stats for post 1234 at time x. Another thought I had is since it doesn't make sense to compare number of fb likes with number of tweets or g+ shares, maybe it makes sense to separate each social measurement into it's own table? Schema 3 DB Popular Posts Table: Post post_id (pk) url title Table: fb_likes fb_like_id (pk) post_id (fk) timestamp value Table: fb_shares fb_shares_id (pk) post_id (fk) timestamp value Table: tweets tweets__id (pk) post_id (fk) timestamp value Table: google_plus google_plus_id (pk) post_id (fk) timestamp value As you can see I am generally lost/unsure of what approach to take. I'm sure this typical type of database problem (storing measurements overtime, i.e temperature statistic) that must have a common solution. Is there a design pattern/model for this, does it have a name? I tried searching for "database periodic data collection" or "database measurements over time" but didn't find anything specific. What would be an appropriate model to solve the needs of this problem?

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• Using C# 4.0’s DynamicObject as a Stored Procedure Wrapper

  - by EltonStoneman

  [Source: http://geekswithblogs.net/EltonStoneman] Overview Ignoring the fashion, I still make a lot of use of DALs – typically when inheriting a codebase with an established database schema which is full of tried and trusted stored procedures. In the DAL a collection of base classes have all the scaffolding, so the usual pattern is to create a wrapper class for each stored procedure, giving typesafe access to parameter values and output. DAL calls then looks like instantiate wrapper-populate parameters-execute call:       using (var sp = new uspGetManagerEmployees())     {         sp.ManagerID = 16;         using (var reader = sp.Execute())         {             //map entities from the output         }     }   Or rolling it all into a fluent DAL call – which is nicer to read and implicitly disposes the resources:   This is fine, the wrapper classes are very simple to handwrite or generate. But as the codebase grows, you end up with a proliferation of very small wrapper classes: The wrappers don't add much other than encapsulating the stored procedure call and giving you typesafety for the parameters. With the dynamic extension in .NET 4.0 you have the option to build a single wrapper class, and get rid of the one-to-one stored procedure to wrapper class mapping. In the dynamic version, the call looks like this:       dynamic getUser = new DynamicSqlStoredProcedure("uspGetManagerEmployees", Database.AdventureWorks);     getUser.ManagerID = 16;       var employees = Fluently.Load<List<Employee>>()                             .With<EmployeeMap>()                             .From(getUser);   The important difference is that the ManagerId property doesn't exist in the DynamicSqlStoredProcedure class. Declaring the getUser object with the dynamic keyword allows you to dynamically add properties, and the DynamicSqlStoredProcedure class intercepts when properties are added and builds them as stored procedure parameters. When getUser.ManagerId = 16 is executed, the base class adds a parameter call (using the convention that parameter name is the property name prefixed by "@"), specifying the correct SQL Server data type (mapping it from the type of the value the property is set to), and setting the parameter value. Code Sample This is worked through in a sample project on github – Dynamic Stored Procedure Sample – which also includes a static version of the wrapper for comparison. (I'll upload this to the MSDN Code Gallery once my account has been resurrected). Points worth noting are: DynamicSP.Data – database-independent DAL that has all the data plumbing code. DynamicSP.Data.SqlServer – SQL Server DAL, thin layer on top of the generic DAL which adds SQL Server specific classes. Includes the DynamicSqlStoredProcedure base class. DynamicSqlStoredProcedure.TrySetMember. Invoked when a dynamic member is added. Assumes the property is a parameter named after the SP parameter name and infers the SqlDbType from the framework type. Adds a parameter to the internal stored procedure wrapper and sets its value. uspGetManagerEmployees – the static version of the wrapper. uspGetManagerEmployeesTest – test fixture which shows usage of the static and dynamic stored procedure wrappers. The sample uses stored procedures from the AdventureWorks database in the SQL Server 2008 Sample Databases. Discussion For this scenario, the dynamic option is very favourable. Assuming your DAL is itself wrapped by a higher layer, the stored procedure wrapper classes have very little reuse. Even if you're codegening the classes and test fixtures, it's still additional effort for very little value. The main consideration with dynamic classes is that the compiler ignores all the members you use, and evaluation only happens at runtime. In this case where scope is strictly limited that's not an issue – but you're relying on automated tests rather than the compiler to find errors, but that should just encourage better test coverage. Also you can codegen the dynamic calls at a higher level. Performance may be a consideration, as there is a first-time-use overhead when the dynamic members of an object are bound. For a single run, the dynamic wrapper took 0.2 seconds longer than the static wrapper. The framework does a good job of caching the effort though, so for 1,000 calls the dynamc version still only takes 0.2 seconds longer than the static: You don't get IntelliSense on dynamic objects, even for the declared members of the base class, and if you've been using class names as keys for configuration settings, you'll lose that option if you move to dynamics. The approach may make code more difficult to read, as you can't navigate through dynamic members, but you do still get full debugging support.     var employees = Fluently.Load<List<Employee>>()                             .With<EmployeeMap>()                             .From<uspGetManagerEmployees>                             (                                 i => i.ManagerID = 16,                                 x => x.Execute()                             );

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• Chester Devs Presentation and source code &ndash; &lsquo;Event Store - an introduction to a DSD for event sourcing and notifications&rsquo;

  - by Liam Westley

  Originally posted on: http://geekswithblogs.net/twickers/archive/2013/11/11/chester-devs-presentation-and-source-code-ndash-lsquoevent-store.aspxThank you everyone at Chester Devs Thanks to Fran Hoey and all the people from Chester Devs. It was a hard drive up and back but the enthusiasm of the audience, with some great questions does make it worthwhile. Presentation and source code My presentation, source code, Event Store runners and text files containing the various command line parameters used for curl is now available on GitHub; https://github.com/westleyl/ChesterDevs-EventStore. Don’t worry if you don’t have a GitHub account, you don’t need one, you can just click on the Download Zip button on the right hand menu to download all the files as a single ZIP file.  If all you want is the PowerPoint presentation, go to https://github.com/westleyl/ChesterDevs-EventStore/blob/master/Powerpoint/Huddle-EventStore.pptx, and click on the View Raw button. Downloading and installing Event Store and Tools Download Event Store http://download.geteventstore.com – I unzipped these files into C:\EventStore\v2.0.1 Download Curl from http://curl.haxx.se/download.html – I downloaded Win64 Generic (with SSL) and unzipped these files into C:\curl version 7.31.0 Running the tools I used in my presentation Demonstration 1 (running Event Store) You can use one of my Event Store runner command files to run the single node version of Event Store, using default ports of 2213 for HTTP and 1113  for TCP, and with a wildcard HTTP pattern.  Both take a single command line parameter to specify the location of the data and log files.  The runners assume the single node executable is located in C:\EventStore\v2.0.1, and will placed data files and logs beneath C:\EventStore\Data, i.e. RunEventStore.cmd TestData1 This will create data files in C:\EventStore\Data\TestData1\Data and log files in C:\EventStore\Data\TestData1\logs. If, when running Event Store you may see the following message, [03288,15,06:23:00.622] Failed to start http server Access is denied You will either need to run Event Store in an administrator console window, or you can use the netsh command to create a firewall permission to allow HTTP listening (this will need to be run, once, in an administrator console window), netsh http add urlacl url=http://*:2213/ user=liam You can always delete this later by running the delete; netsh http delete urlacl url=http://*:2213/ If you want to confirm that everything is running OK, open the management console in a browser by navigating to http://127.0.0.1:2213. If at any point you are asked for a user name and password use the default of ‘admin’/‘changeit’. Demonstration 2 (reading and adding data, curl) In my second demonstration I used curl directly from the console to read streams, write events and then read back those events. On GitHub I have included is a set of curl commands, CurlCommandLine.txt, and a sample data file, SampleData.json, to load an event into a DDDNorth3 stream. As there is not much data in the Event Store at this point I used the $stats-127.0.0.1:2113 which is a stream containing performance statistics for Event Store and is updated every 30 seconds (default). Demonstration 3 (projections) On GitHub I have included a sample projection, Projection-ByRoom.txt, which will create streams based on the room on which a session was held on the DDDNorth3 agenda. Browse to the management console, http://127.0.0.1:2213.  Click on Projections, New Projection, give it a name, Sessions-ByRoom, and copy in the JavaScript in the Projection-ByRoom.txt file.  Select Continuous, tick Emit Enabled and then click on Post. It should run immediately. You may by challenged for the administration login for the management console, if so use the default user name and password; 'admin'/'changeit'. Demonstration 4 (C# client) The final demonstration was the Visual Studio 2012 project using the Event Store client – referenced directly as C:\EventStore\v2.0.1\EventStore.ClientAPI.dll, although you can switch this to the latest Event Store client NuGet package. The source code provides a console app for viewing projections with the projection manager (HTTP connection), as well as containing a full set of data for the entire DDDNorth3 agenda.  It also deals with the strategy for reading newest events backwards to older events and ignoring older events that have been superseded. Resources Event Store home page: http://www.geteventstore.com/ Event Store source code on GitHub: https://github.com/eventstore/eventstore Event Store documentation on GitHub: https://github.com/eventstore/eventstore/wiki (includes index to @RobAshton’s blog series on Event Store at https://github.com/eventstore/eventstore/wiki#rob-ashton---projections-series) Event Store forum in Google Groups: https://groups.google.com/forum/?fromgroups#!forum/event-store TopShelf Windows service wrapper is available on github: https://gist.github.com/trbngr/5083266

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• DDD North 3 Presentation and source code &ndash; &lsquo;Event Store - an introduction to a DSD for event sourcing and notifications&rsquo;

  - by Liam Westley

  Originally posted on: http://geekswithblogs.net/twickers/archive/2013/10/15/ddd-north-3-presentation-and-source-code-ndash-lsquoevent-store.aspxThank you everyone at DDD North Thanks to all the people who helped organise the cracking conference that is DDD North 3, returning to Sunderland, and the great facilities at the University of Sunderland, and the fine drinks reception at Sunderland Software City.  The whole event wouldn’t be possible without the sponsors who ensured over 400 people were kept fed and watered so they could enjoy the impressive range of sessions. And lastly, a thank you to all those delegates who gave up their free time on a Saturday to spend a day dashing between lecture rooms, including a late change to my room which saw 40 people having to brave a journey between buildings in the fine drizzle. The enthusiasm from the delegates always helps recharge my geek batteries. Presentation and source code My presentation, source code, Event Store runners and text files containing the various command line parameters used for curl is now available on GitHub; https://github.com/westleyl/DDDNorth3-EventStore. Don’t worry if you don’t have a GitHub account, you don’t need one, you can just click on the Download Zip button on the right hand menu to download all the files as a single ZIP file.  If all you want is the PowerPoint presentation, go to https://github.com/westleyl/DDDNorth3-EventStore/blob/master/Powerpoint/DDDNorth-EventStore.pptx, and click on the View Raw button. Downloading and installing Event Store and Tools Download Event Store http://download.geteventstore.com – I unzipped these files into C:\EventStore\v2.0.1 Download Curl from http://curl.haxx.se/download.html – I downloaded Win64 Generic (with SSL) and unzipped these files into C:\curl version 7.31.0 Running the tools I used in my presentation Demonstration 1 (running Event Store) You can use one of my Event Store runner command files to run the single node version of Event Store, using default ports of 2213 for HTTP and 1113  for TCP, and with a wildcard HTTP pattern.  Both take a single command line parameter to specify the location of the data and log files.  The runners assume the single node executable is located in C:\EventStore\v2.0.1, and will placed data files and logs beneath C:\EventStore\Data, i.e. RunEventStore.cmd TestData1 This will create data files in C:\EventStore\Data\TestData1\Data and log files in C:\EventStore\Data\TestData1\logs. If, when running Event Store you may see the following message, [03288,15,06:23:00.622] Failed to start http server Access is denied You will either need to run Event Store in an administrator console window, or you can use the netsh command to create a firewall permission to allow HTTP listening (this will need to be run, once, in an administrator console window), netsh http add urlacl url=http://*:2213/ user=liam You can always delete this later by running the delete; netsh http delete urlacl url=http://*:2213/ If you want to confirm that everything is running OK, open the management console in a browser by navigating to http://127.0.0.1:2213. If at any point you are asked for a user name and password use the default of ‘admin’/‘changeit’.   Demonstration 2 (reading and adding data, curl) In my second demonstration I used curl directly from the console to read streams, write events and then read back those events. On GitHub I have included is a set of curl commands, CurlCommandLine.txt, and a sample data file, SampleData.json, to load an event into a DDDNorth3 stream. As there is not much data in the Event Store at this point I used the $stats-127.0.0.1:2113 which is a stream containing performance statistics for Event Store and is updated every 30 seconds (default). Demonstration 3 (projections) On GitHub I have included a sample projection, Projection-ByRoom.txt, which will create streams based on the room on which a session was held on the DDDNorth3 agenda. Browse to the management console, http://127.0.0.1:2213.  Click on Projections, New Projection, give it a name, Sessions-ByRoom, and copy in the JavaScript in the Projection-ByRoom.txt file.  Select Continuous, tick Emit Enabled and then click on Post. It should run immediately. You may by challenged for the administration login for the management console, if so use the default user name and password; 'admin'/'changeit'.   Demonstration 4 (C# client) The final demonstration was the Visual Studio 2012 project using the Event Store client – referenced directly as C:\EventStore\v2.0.1\EventStore.ClientAPI.dll, although you can switch this to the latest Event Store client NuGet package. The source code provides a console app for viewing projections with the projection manager (HTTP connection), as well as containing a full set of data for the entire DDDNorth3 agenda.  It also deals with the strategy for reading newest events backwards to older events and ignoring older events that have been superseded. Resources Event Store home page: http://www.geteventstore.com/ Event Store source code on GitHub: https://github.com/eventstore/eventstore Event Store documentation on GitHub: https://github.com/eventstore/eventstore/wiki (includes index to @RobAshton’s blog series on Event Store at https://github.com/eventstore/eventstore/wiki#rob-ashton---projections-series) Event Store forum in Google Groups: https://groups.google.com/forum/?fromgroups#!forum/event-store TopShelf Windows service wrapper is available on github: https://gist.github.com/trbngr/5083266

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• CodePlex Daily Summary for Sunday, March 07, 2010

  CodePlex Daily Summary for Sunday, March 07, 2010New ProjectsAlgorithminator: Universal .NET algorithm visualizer, which helps you to illustrate any algorithm, written in any .NET language. Still in development.ALToolkit: Contains a set of handy .NET components/classes. Currently it contains: * A Numeric Text Box (an Extended NumericUpDown) * A Splash Screen base fo...Automaton Home: Automaton is a home automation software built with a n-Tier, MVVM pattern utilzing WCF, EF, WPF, Silverlight and XBAP.Developer Controls: Developer Controls contains various controls to help build applications that can script/write code.Dynamic Reference Manager: Dynamic Reference Manager is a set (more like a small group) of classes and attributes written in C# that allows any .NET program to reference othe...indiologic: Utilities of an IndioNeural Cryptography in F#: This project is my magistracy resulting work. It is intended to be an example of using neural networks in cryptography. Hashing functions are chose...Particle Filter Visualization: Particle Filter Visualization Program for the Intel Science and Engineering FairPólya: Efficient, immutable, polymorphic collections. .Net lacks them, we provide them*. * By we, we mean I; and by efficient, I mean hopefully so.project euler solutions from mhinze: mhinze project euler solutionsSilverlight 4 and WCF multi layer: Silverlight 4 and WCF multi layersqwarea: Project for a browser-based, minimalistic, massively multiplayer strategy game. Part of the "Génie logiciel et Cloud Computing" course of the ENS (...SuperSocket: SuperSocket, a socket application framework can build FTP/SMTP/POP server easilyToast (for ASP.NET MVC): Dynamic, developer & designer friendly content injection, compression and optimization for ASP.NET MVCNew ReleasesALToolkit: ALToolkit 1.0: Binary release of the libraries containing: NumericTextBox SplashScreen Based on the VB.NET code, but that doesn't really matter.Blacklist of Providers: 1.0-Milestone 1: Blacklist of Providers.Milestone 1In this development release implemented - Main interface (Work Item #5453) - Database (Work Item #5523)C# Linear Hash Table: Linear Hash Table b2: Now includes a default constructor, and will throw an exception if capacity is not set to a power of 2 or loadToMaintain is below 1.Composure: CassiniDev-Trunk-40745-VS2010.rc1.NET4: A simple port of the CassiniDev portable web server project for Visual Studio 2010 RC1 built against .NET 4.0. The WCF tests currently fail unless...Developer Controls: DevControls: These are the version 1.0 releases of these controls. Download the individually or all together (in a .zip file). More releases coming soon!Dynamic Reference Manager: DRM Alpha1: This is the first release. I'm calling it Alpha because I intend implementing other functions, but I do not intend changing the way current functio...ESB Toolkit Extensions: Tellago SOA ESB Extenstions v0.3: Windows Installer file that installs Library on a BizTalk ESB 2.0 system. This Install automatically configures the esb.config to use the new compo...GKO Libraries: GKO Libraries 0.1 Alpha: 0.1 AlphaHome Access Plus+: v3.0.3.0: Version 3.0.3.0 Release Change Log: Added Announcement Box Removed script files that aren't needed Fixed & issue in directory path Stylesheet...Icarus Scene Engine: Icarus Scene Engine 1.10.306.840: Icarus Professional, Icarus Player, the supporting software for Icarus Scene Engine, with some included samples, and the start of a tutorial (with ...mavjuz WndLpt: wndlpt-0.2.5: New: Response to 5 LPT inputs "test i 1" New: Reaction to 12 LPT outputs "test q 8" New: Reaction to all LPT pins "test pin 15" New: Syntax: ...Neural Cryptography in F#: Neural Cryptography 0.0.1: The most simple version of this project. It has a neural network that works just like logical AND and a possibility to recreate neural network from...Password Provider: 1.0.3: This release fixes a bug which caused the program to crash when double clicking on a generic item.RoTwee: RoTwee 6.2.0.0: New feature is as next. 16649 Add hashtag for tweet of tune.Now you can tweet your playing tune with hashtag.Visual Studio DSite: Picture Viewer (Visual C++ 2008): This example source code allows you to view any picture you want in the click of a button. All you got to do is click the button and browser via th...WatchersNET CKEditor™ Provider for DotNetNuke: CKEditor Provider 1.8.00: Whats New File Browser: Folders & Files View reworked File Browser: Folders & Files View reworked File Browser: Folders are displayed as TreeVi...WSDLGenerator: WSDLGenerator 0.0.0.4: - replaced CommonLibrary.dll by CommandLineParser.dll - added better support for custom complex typesMost Popular ProjectsMetaSharpSilverlight ToolkitASP.NET Ajax LibraryAll-In-One Code FrameworkWindows 7 USB/DVD Download Toolニコ生アラートWindows Double ExplorerVirtual Router - Wifi Hot Spot for Windows 7 / 2008 R2Caliburn: An Application Framework for WPF and SilverlightArkSwitchMost Active ProjectsUmbraco CMSRawrSDS: Scientific DataSet library and toolsBlogEngine.NETjQuery Library for SharePoint Web Servicespatterns & practices – Enterprise LibraryIonics Isapi Rewrite FilterFarseer Physics EngineFasterflect - A Fast and Simple Reflection APIFluent Assertions

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• Maven2 multi-module ejb 3.1 project - deployment error

  - by gerry

  The problem is taht I get the following error qhile deploying my project to Glassfish: java.lang.RuntimeException: Unable to load EJB module. DeploymentContext does not contain any EJB Check archive to ensure correct packaging But, let us start on how the project structure looks like in Maven2... I've build the following scenario: MultiModuleJavaEEProject - parent module - model --- packaged as jar - ejb1 ---- packaged as ebj - ejb2 ---- packaged as ebj - web ---- packaged as war So model, ejb1, ejb2 and web are children/modules of the parent MultiModuleJavaEEProject. _ejb1 depends on model. _ejb2 depends on ejb1. _web depends on ejb2. the pom's look like: _parent: <?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>org.dyndns.geraldhuber.testing</groupId> <artifactId>MultiModuleJavaEEProject</artifactId> <packaging>pom</packaging> <version>1.0</version> <name>MultiModuleJavaEEProject</name> <url>http://maven.apache.org</url> <modules> <module>model</module> <module>ejb1</module> <module>ejb2</module> <module>web</module> </modules> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.7</version> <scope>test</scope> </dependency> </dependencies> <build> <pluginManagement> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.6</source> <target>1.6</target> </configuration> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-ejb-plugin</artifactId> <version>2.2</version> <configuration> <ejbVersion>3.1</ejbVersion> <jarName>${project.groupId}.${project.artifactId}-${project.version}</jarName> </configuration> </plugin> </plugins> </pluginManagement> </build> </project> _model: <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>testing</groupId> <artifactId>MultiModuleJavaEEProject</artifactId> <version>1.0</version> </parent> <artifactId>model</artifactId> <packaging>jar</packaging> <version>1.0</version> <name>model</name> <url>http://maven.apache.org</url> </project> _ejb1: <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>testing</groupId> <artifactId>MultiModuleJavaEEProject</artifactId> <version>1.0</version> </parent> <artifactId>ejb1</artifactId> <packaging>ejb</packaging> <version>1.0</version> <name>ejb1</name> <url>http://maven.apache.org</url> <dependencies> <dependency> <groupId>org.glassfish</groupId> <artifactId>javax.ejb</artifactId> <version>3.0</version> <scope>provided</scope> </dependency> <dependency> <groupId>testing</groupId> <artifactId>model</artifactId> <version>1.0</version> </dependency> </dependencies> </project> _ejb2: <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>testing</groupId> <artifactId>MultiModuleJavaEEProject</artifactId> <version>1.0</version> </parent> <artifactId>ejb2</artifactId> <packaging>ejb</packaging> <version>1.0</version> <name>ejb2</name> <url>http://maven.apache.org</url> <dependencies> <dependency> <groupId>org.glassfish</groupId> <artifactId>javax.ejb</artifactId> <version>3.0</version> <scope>provided</scope> </dependency> <dependency> <groupId>testing</groupId> <artifactId>ejb1</artifactId> <version>1.0</version> </dependency> </dependencies> </project> _web: <?xml version="1.0" encoding="UTF-8"?> <project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <modelVersion>4.0.0</modelVersion> <parent> <artifactId>MultiModuleJavaEEProject</artifactId> <groupId>testing</groupId> <version>1.0</version> </parent> <groupId>testing</groupId> <artifactId>web</artifactId> <version>1.0</version> <packaging>war</packaging> <name>web Maven Webapp</name> <url>http://maven.apache.org</url> <dependencies> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.4</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.glassfish</groupId> <artifactId>javax.ejb</artifactId> <version>3.0</version> <scope>provided</scope> </dependency> <dependency> <groupId>testing</groupId> <artifactId>ejb2</artifactId> <version>1.0</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-war-plugin</artifactId> <version>2.0</version> <configuration> <archive> <manifest> <addClasspath>true</addClasspath> </manifest> </archive> </configuration> </plugin> </plugins> <finalName>web</finalName> </build> </project> And the model is just a simple Pojo: package testing.model; public class Data { private String data; public String getData() { return data; } public void setData(String data) { this.data = data; } } And the ejb1 contains only one STATELESS ejb. package testing.ejb1; import javax.ejb.Stateless; import testing.model.Data; @Stateless public class DataService { private Data data; public DataService(){ data = new Data(); data.setData("Hello World!"); } public String getDataText(){ return data.getData(); } } As well as the ejb2 is only a stateless ejb: package testing.ejb2; import javax.ejb.EJB; import javax.ejb.Stateless; import testing.ejb1.DataService; @Stateless public class Service { @EJB DataService service; public Service(){ } public String getText(){ return service.getDataText(); } } And the web module contains only a Servlet: package testing.web; import java.io.IOException; import java.io.PrintWriter; import javax.ejb.EJB; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import testing.ejb2.Service; public class SimpleServlet extends HttpServlet { @EJB Service service; public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { PrintWriter out = response.getWriter(); out.println( "SimpleServlet Executed" ); out.println( "Text: "+service.getText() ); out.flush(); out.close(); } } And the web.xml file in the web module looks like: <!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd" > <web-app> <display-name>Archetype Created Web Application</display-name> <servlet> <servlet-name>simple</servlet-name> <servlet-class>testing.web.SimpleServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>simple</servlet-name> <url-pattern>/simple</url-pattern> </servlet-mapping> </web-app> So no further files are set up by me. There is no ejb-jar.xml in any ejb files, because I'm using EJB 3.1. So I think ejb-jar.xml descriptors are optional. I this right? But the problem is, the already mentioned error: java.lang.RuntimeException: Unable to load EJB module. DeploymentContext does not contain any EJB Check archive to ensure correct packaging Can anybody help?

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• Comments on Comments

  - by Joe Mayo

  I almost tweeted a reply to Capar Kleijne's question about comments on Twitter, but realized that my opinion exceeded 140 characters. The following is based upon my experience with extremes and approaches that I find useful in code comments. There are a couple extremes that I've seen and reasons why people go the distance in each approach. The most common extreme is no comments in the code at all.  A few bad reasons why this happens is because a developer is in a hurry, sloppy, or is interested in job preservation. The unfortunate result is that the code is difficult to understand and hard to maintain. The drawbacks to no comments in code are a primary reason why teachers drill the need for commenting code into our heads.  This viewpoint assumes the lack of comments are bad because the code is bad, but there is another reason for not commenting that is gaining more popularity. I've heard/and read that code should be self documenting. Following this thought pattern, if code is well written with meaningful names, there should not be a reason for comments.  An addendum to this argument is that comments are often neglected and get out-of-date, but the code is what is kept up-to-date. Presumably, if code contained very good naming, it would be easy to maintain.  This is a noble perspective and I like the practice of meaningful naming of identifiers. However, I think it's also an extreme approach that doesn't cover important cases.  i.e. If an identifier is named badly (subjective differences in opinion) or not changed appropriately during maintenance, then the badly named identifier is no more useful than a stale comment. These were the two no-comment extremes, so let's look at the too many comments extreme. On a regular basis, I'll see cases where the code is over-commented; not nearly as often as the no-comment scenarios, but still prevalent.  These are examples of where every single line in the code is commented.  These comments make the code harder to read because they get in the way of the algorithm.  In most cases, the comments parrot what each line of code does.  If a developer understands the language, then most statements are immediately intuitive.  i.e. what use is it to say that I'm assigning foo to bar when it's clear what the code is doing. I think that over-commenting code is a waste of time that slows down initial development and maintenance.  Understandably, the developer's intentions are admirable because they've had it beaten into their heads that they must comment. However, I think it's an extreme and prefer a more moderate approach. I don't think the extremes do justice to code because each can make maintenance harder.  No comments on bad code is obviously a problem, but the other two extremes are subtle and require qualification to address properly. The problem I see with the code-as-documentation approach is that it doesn't lift the developer out of the algorithm to identify dependencies, intentions, and hacks. Any developer can read code and follow an algorithm, but they still need to know where it fits into the big picture of the application. Because of indirections with language features like interfaces, delegates, and virtual members, code can become complex.  Occasionally, it's useful to point out a nuance or reason why a piece of code is there. i.e. If you've building an app that communicates via HTTP, you'll have certain headers to include for the endpoint, and it could be useful to point out why the code for setting those header values is there and how they affect the application. An argument against this could be that you should extract that code into a separate method with a meaningful name to describe the scenario.  My problem with such an approach would be that your code base becomes even more difficult to navigate and work with because you have all of this extra code just to make the code more meaningful. My opinion is that a simple and well-stated comment stating the reasons and intention for the code is more natural and convenient to the initial developer and maintainer.  I just don't agree with the approach of going out of the way to avoid making a comment.  I'm also concerned that some developers would take this approach as an excuse to not comment their bad code. Another area where I like comments is on documentation comments.  Java has it and so does C# and VB.  It's convenient because we can build automated tools that extract these comments.  These extracted comments are often much better than no documentation at all.  The "go read the code" answer always doesn't fulfill the need for a quick summary of an API. To summarize, I think that the extremes of no comments and too many comments are less than desirable approaches. I prefer documentation comments to explain each class and member (API level) and code comments as necessary to supplement well-written code. Joe

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• Top 4 Lame Tech Blogging Posts

  - by jkauffman

  From a consumption point of view, tech blogging is a great resource for one-off articles on niche subjects. If you spend any time reading tech blogs, you may find yourself running into several common, useless types of posts tech bloggers slip into. Some of these lame posts may just be natural due to common nerd psychology, and some others are probably due to lame, lemming-like laziness. I’m sure I’ll do my fair share of fitting the mold, but I quickly get bored when I happen upon posts that hit these patterns without any real purpose or personal touches. 1. The Content Regurgitation Posts This is a common pattern fueled by the starving pan-handlers in the web traffic economy. These are posts that are terse opinions or addendums to an existing post. I commonly see these involve huge block quotes from the linked article which almost always produces over 50% of the post itself. I’ve accidentally gone to these posts when I’m knowingly only interested in the source material. Web links can degrade as well, so if the source link is broken, then, well, I’m pretty steamed. I see this occur with simple opinions on technologies, Stack Overflow solutions, or various tech news like posts from Microsoft. It’s not uncommon to go to the linked article and see the author announce that he “added a blog post” as a response or summary of the topic. This is just rude, but those who do it are probably aware of this. It’s a matter of winning that sweet, juicy web traffic. I doubt this leeching is fooling anybody these days. I would like to rally human dignity and urge people to avoid these types of posts, and just leave a comment on the source material. 2. The “Sorry I Haven’t Posted In A While” Posts This one is far too common. You’ll most likely see this quote somewhere in the body of the offending post: I have been really busy. If the poster is especially guilt-ridden, you’ll see a few volleys of excuses. Here are some common reasons I’ve seen, which I’ll list from least to most painfully awkward. Out of town Vague allusions to personal health problems (these typically includes phrases like “sick”, “treatment'”, and “all better now!”) “Personal issues” (which I usually read as "divorce”) Graphic or specific personal health problems (maximum awkwardness potential is achieved if you see links to charity fund websites) I can’t help but to try over-analyzing why this occurs. Personally, I see this an an amalgamation of three plain factors: Life happens Us nerds are duty-driven, and driven to guilt at personal inefficiencies Tech blogs can become personal journals I don’t think we can do much about the first two, but on the third I think we could certainly contain our urges. I’m a pretty boring guy and, whether or I like it or not, I have an unspoken duty to protect the world from hearing about my unremarkable existence. Nobody cares what kind of sandwich I’m eating. Similarly, if I disappear for a while, it’s unlikely that anybody who happens upon my blog would care why. Rest assured, if I stop posting for a while due to a vasectomy, you will be the first to know. 3. The “At A Conference”, or “Conference Review” Posts I don’t know if I’m like everyone else on this one, but I have never been successfully interested in these posts. It even sounds like a good idea: if I can’t make it to a particular conference (like the KCDC this year), wouldn’t I be interested in a concentrated summary of events? Apparently, no! Within this realm, I’ve never read a post by a blogger that held my interest. What really baffles is is that, for whatever reason, I am genuinely engaged and interested when talking to someone in person regarding the same topic. I have noticed the same phenomenon when hearing about others’ vacations. If someone sends me an email about their vacation, I gloss over it and forget about it quickly. In contrast, if I’m speaking to that individual in person about their vacation, I’m actually interested. I’m unsure why the written medium eradicates the intrigue. I was raised by a roaming pack of friendly wild video games, so that may be a factor. 4. The “Top X Number of Y’s That Z” Posts I’ve seen this one crop up a lot more in the past few of years. Here are some fabricated examples: 5 Easy Ways to Improve Your Code Top 7 Good Habits Programmers Learn From Experience The 8 Things to Consider When Giving Estimates Top 4 Lame Tech Blogging Posts These are attention-grabbing headlines, and I’d assume they rack up hits. In fact, I enjoy a good number of these. But, I’ve been drawn to articles like this just to find an endless list of identically formatted posts on the blog’s archive sidebar. Often times these posts have overlapping topics, too. These types of posts give the impression that the author has given thought to prioritize and organize the points as a result of a comprehensive consideration of a particular topic. Did the author really weigh all the possibilities when identifying the “Top 4 Lame Tech Blogging Patterns”? Unfortunately, probably not. What a tool. To reiterate, I still enjoy the format, but I feel it is abused. Nowadays, I’m pretty skeptical when approaching posts in this format. If these trends continue, my brain will filter these blog posts out just as effectively as it ignores the encroaching “do xxx with this one trick” advertisements. Conclusion To active blog readers, I hope my guide has served you precious time in being able to identify lame blog posts at a glance. Save time and energy by skipping over the chaff of the internet! And if you author a blog, perhaps my insight will help you to avoid the occasional urge to produce these needless filler posts.

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• Management and Monitoring Tools for Windows Azure

  - by BuckWoody

  With such a large platform, Windows Azure has a lot of moving parts. We’ve done our best to keep the interface as simple as possible, while giving you the most control and visibility we can. However, as with most Microsoft products, there are multiple ways to do something – and I’ve always found that to be a good strength. Depending on the situation, I might want a graphical interface, a command-line interface, or just an API so I can incorporate the management into my own tools, or have third-party companies write other tools. While by no means exhaustive, I thought I might put together a quick list of a few tools you can use to manage and monitor Windows Azure components, from our IaaS, SaaS and PaaS offerings. Some of the products focus on one area more than another, but all are available today. I’ll try and maintain this list to keep it current, but make sure you check the date of this post’s update – if it’s more than six months old, it’s most likely out of date. Things move fast in the cloud. The Windows Azure Management Portal The primary tool for managing Windows Azure is our portal – most everything you need is there, from creating new services to querying a database. There are two versions as of this writing – a Silverlight client version, and a newer HTML5 version. The latter is being updated constantly to be in parity with the Silverlight client. There’s a balance in this portal between simplicity and power – we’re following the “less is more” approach, with increasing levels of detail as you work through the portal rather than overwhelming you with a single, long “more is more” page. You can find the Portal here: http://windowsazure.com (then click “Log In” and then “Portal”) Windows Azure Management API You can also use programming tools to either write your own interface, or simply provide management functions directly within your solution. You have two options – you can use the more universal REST API’s, which area bit more complex but work with any system that can write to them, or the more approachable .NET API calls in code. You can find the reference for the API’s here: http://msdn.microsoft.com/en-us/library/windowsazure/ee460799.aspx  All Class Libraries, for each part of Windows Azure: http://msdn.microsoft.com/en-us/library/ee393295.aspx  PowerShell Command-lets PowerShell is one of the most powerful scripting languages I’ve used with Windows – and it’s baked into all of our products. When you need to work with multiple servers, scripting is really the only way to go, and the Windows Azure PowerShell Command-Lets allow you to work across most any part of the platform – and can even be used within the services themselves. You can do everything with them from creating a new IaaS, PaaS or SaaS service, to controlling them and even working with security and more. You can find more about the Command-Lets here: http://wappowershell.codeplex.com/documentation (older link, still works, will point you to the new ones as well) We have command-line utilities for other operating systems as well: https://www.windowsazure.com/en-us/manage/downloads/  Video walkthrough of using the Command-Lets: http://channel9.msdn.com/Events/BUILD/BUILD2011/SAC-859T  System Center System Center is actually a suite of graphical tools you can use to manage, deploy, control, monitor and tune software from Microsoft and even other platforms. This will be the primary tool we’ll recommend for managing a hybrid or contiguous management process – and as time goes on you’ll see more and more features put into System Center for the entire Windows Azure suite of products. You can find the Management Pack and README for it here: http://www.microsoft.com/en-us/download/details.aspx?id=11324  SQL Server Management Studio / Data Tools / Visual Studio SQL Server has two built-in management and development, and since Version 2008 R2, you can use them to manage Windows Azure Databases. Visual Studio also lets you connect to and manage portions of Windows Azure as well as Windows Azure Databases. You can read more about Visual Studio here: http://msdn.microsoft.com/en-us/library/windowsazure/ee405484  You can read more about the SQL tools here: http://msdn.microsoft.com/en-us/library/windowsazure/ee621784.aspx  Vendor-Provided Tools Microsoft does not suggest or endorse a specific third-party product. We do, however, use them, and see lots of other customers use them. You can browse to these sites to learn more, and chat with their folks directly on how they support Windows Azure. Cerebrata: Tools for managing from the command-line, graphical diagnostics, graphical storage management - http://www.cerebrata.com/  Quest Cloud Tools: Monitoring, Storage Management, and costing tools - http://communities.quest.com/community/cloud-tools  Paraleap: Monitoring tool - http://www.paraleap.com/AzureWatch  Cloudgraphs: Monitoring too -  http://www.cloudgraphs.com/  Opstera: Monitoring for Windows Azure and a Scale-out pattern manager - http://www.opstera.com/products/Azureops/  Compuware: SaaS performance monitoring, load testing -  http://www.compuware.com/application-performance-management/gomez-apm-products.html  SOASTA: Penetration and Security Testing - http://www.soasta.com/cloudtest/enterprise/  LoadStorm: Load-testing tool - http://loadstorm.com/windows-azure  Open-Source Tools This is probably the most specific set of tools, and the list I’ll have to maintain most often. Smaller projects have a way of coming and going, so I’ll try and make sure this list is current. Windows Azure MMC: (I actually use this one a lot) http://wapmmc.codeplex.com/  Windows Azure Diagnostics Monitor: http://archive.msdn.microsoft.com/wazdmon  Azure Application Monitor: http://azuremonitor.codeplex.com/  Azure Web Log: http://www.xentrik.net/software/azure_web_log.html  Cloud Ninja:Multi-Tennant billing and performance monitor -  http://cnmb.codeplex.com/  Cloud Samurai: Multi-Tennant Management- http://cloudsamurai.codeplex.com/    If you have additions to this list, please post them as a comment and I’ll research and then add them. Thanks!

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• Knockoutjs - stringify to handling observables and custom events

  - by Renso

  Goal: Once you viewmodel has been built and populated with data, at some point it goal of it all is to persist the data to the database (or some other media). Regardless of where you want to save it, your client-side viewmodel needs to be converted to a JSON string and sent back to the server. Environment considerations: jQuery 1.4.3+ Knockoutjs version 1.1.2   How to: So let’s set the stage, you are using Knockoutjs and you have a viewmodel with some Knockout dependencies. You want to make sure it is in the proper JSON format and via ajax post it to the server for persistence.   First order of business is to deal with the viewmodel (JSON) object. To most the JSON stringifier sounds familiar. The JSON stringifier converts JavaScript data structures into JSON text. JSON does not support cyclic data structures, so be careful to not give cyclical structures to the JSON stringifier. You may ask, is this the best way to do it? What about those observables and other Knockout properties that I don’t want to persist or want their actual value persisted and not their function, etc. Not sure if you were aware, but KO already has a method; ko.utils.stringifyJson() - it's mostly just a wrapper around JSON.stringify. (which is native in some browsers, and can be made available by referencing json2.js in others). What does it do that the regular stringify does not is that it automatically converts observable, dependentObservable, or observableArray to their underlying value to JSON. Hold on! There is a new feature in this version of Knockout, the ko.toJSON. It is part of the core library and it will clone the view model’s object graph, so you don’t mess it up after you have stringified  it and unwrap all its observables. It's smart enough to avoid reference cycles. Since you are using the MVVM pattern it would assume you are not trying to reference DOM nodes from your view. Wait a minute. I can already see this info on the http://knockoutjs.com/examples/contactsEditor.html website, why mention it all here? First of this is a much nicer blog, no orange ? At this time, you may want to have a look at the blog and see what I am talking about. See the save event, how they stringify the view model’s contacts only? That’s cool but what if your view model is a representation of your object you want to persist, meaning it has no property that represents the json object you want to persist, it is the view model itself. The example in http://knockoutjs.com/examples/contactsEditor.html assumes you have a list of contacts you may want to persist. In the example here, you want to persist the view model itself. The viewmodel here looks something like this:     var myViewmodel = {         accountName: ko.observable(""),         accountType: ko.observable("Active")     };     myViewmodel.isItActive = ko.dependentObservable(function () {         return myViewmodel.accountType() == "Active";     });     myViewmodel.clickToSaveMe = function() {         SaveTheAccount();     }; Here is the function in charge of saving the account: Function SaveTheAccount() {     $.ajax({         data: ko.toJSON(viewmodel),         url: $('#ajaxSaveAccountUrl').val(),         type: "POST",         dataType: "json",         async: false,         success: function (result) {             if (result && result.Success == true) {                 $('#accountMessage').html('<span class="fadeMyContainerSlowly">The account has been saved</span>').show();                 FadeContainerAwaySlowly();             }         },         error: function (xmlHttpRequest, textStatus, errorThrown) {             alert('An error occurred: ' + errorThrown);         }     }); //ajax }; Try run this and your browser will eventually freeze up or crash. Firebug will tell you that you have a repetitive call to the first function call in your model that keeps firing infinitely.  What is happening is that Knockout serializes the view model to a JSON string by traversing the object graph and firing off the functions, again-and-again. Not sure why it does that, but it does. So what is the work around: Nullify your function calls and then post it:         var lightweightModel = viewmodel.clickToSaveMe = null;         data: ko.toJSON(lightweightModel), So then I traced the JSON string on the server and found it having issues with primitive types. C#, by the way. So I changed ko.toJSON(model) to ko.toJS(model), and that solved my problem. Of course you could just create a property on the viewmodel for the account itself, so you only have to serialize the property and not the entire viewmodel. If that is an option then that would be the way to go. If your view model contains other properties in the view model that you also want to post then that would not be an option and then you’ll know what to watch out for. Hope this helps.

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• String Format for DateTime in C#

  - by SAMIR BHOGAYTA

  String Format for DateTime [C#] This example shows how to format DateTime using String.Format method. All formatting can be done also using DateTime.ToString method. Custom DateTime Formatting There are following custom format specifiers y (year), M (month), d (day), h (hour 12), H (hour 24), m (minute), s (second), f (second fraction), F (second fraction, trailing zeroes are trimmed), t (P.M or A.M) and z (time zone). Following examples demonstrate how are the format specifiers rewritten to the output. [C#] // create date time 2008-03-09 16:05:07.123 DateTime dt = new DateTime(2008, 3, 9, 16, 5, 7, 123); String.Format("{0:y yy yyy yyyy}", dt); // "8 08 008 2008" year String.Format("{0:M MM MMM MMMM}", dt); // "3 03 Mar March" month String.Format("{0:d dd ddd dddd}", dt); // "9 09 Sun Sunday" day String.Format("{0:h hh H HH}", dt); // "4 04 16 16" hour 12/24 String.Format("{0:m mm}", dt); // "5 05" minute String.Format("{0:s ss}", dt); // "7 07" second String.Format("{0:f ff fff ffff}", dt); // "1 12 123 1230" sec.fraction String.Format("{0:F FF FFF FFFF}", dt); // "1 12 123 123" without zeroes String.Format("{0:t tt}", dt); // "P PM" A.M. or P.M. String.Format("{0:z zz zzz}", dt); // "-6 -06 -06:00" time zone You can use also date separator / (slash) and time sepatator : (colon). These characters will be rewritten to characters defined in the current DateTimeForma­tInfo.DateSepa­rator and DateTimeForma­tInfo.TimeSepa­rator. [C#] // date separator in german culture is "." (so "/" changes to ".") String.Format("{0:d/M/yyyy HH:mm:ss}", dt); // "9/3/2008 16:05:07" - english (en-US) String.Format("{0:d/M/yyyy HH:mm:ss}", dt); // "9.3.2008 16:05:07" - german (de-DE) Here are some examples of custom date and time formatting: [C#] // month/day numbers without/with leading zeroes String.Format("{0:M/d/yyyy}", dt); // "3/9/2008" String.Format("{0:MM/dd/yyyy}", dt); // "03/09/2008" // day/month names String.Format("{0:ddd, MMM d, yyyy}", dt); // "Sun, Mar 9, 2008" String.Format("{0:dddd, MMMM d, yyyy}", dt); // "Sunday, March 9, 2008" // two/four digit year String.Format("{0:MM/dd/yy}", dt); // "03/09/08" String.Format("{0:MM/dd/yyyy}", dt); // "03/09/2008" Standard DateTime Formatting In DateTimeForma­tInfo there are defined standard patterns for the current culture. For example property ShortTimePattern is string that contains value h:mm tt for en-US culture and value HH:mm for de-DE culture. Following table shows patterns defined in DateTimeForma­tInfo and their values for en-US culture. First column contains format specifiers for the String.Format method. Specifier DateTimeFormatInfo property Pattern value (for en-US culture) t ShortTimePattern h:mm tt d ShortDatePattern M/d/yyyy T LongTimePattern h:mm:ss tt D LongDatePattern dddd, MMMM dd, yyyy f (combination of D and t) dddd, MMMM dd, yyyy h:mm tt F FullDateTimePattern dddd, MMMM dd, yyyy h:mm:ss tt g (combination of d and t) M/d/yyyy h:mm tt G (combination of d and T) M/d/yyyy h:mm:ss tt m, M MonthDayPattern MMMM dd y, Y YearMonthPattern MMMM, yyyy r, R RFC1123Pattern ddd, dd MMM yyyy HH':'mm':'ss 'GMT' (*) s SortableDateTi­mePattern yyyy'-'MM'-'dd'T'HH':'mm':'ss (*) u UniversalSorta­bleDateTimePat­tern yyyy'-'MM'-'dd HH':'mm':'ss'Z' (*) (*) = culture independent Following examples show usage of standard format specifiers in String.Format method and the resulting output. [C#] String.Format("{0:t}", dt); // "4:05 PM" ShortTime String.Format("{0:d}", dt); // "3/9/2008" ShortDate String.Format("{0:T}", dt); // "4:05:07 PM" LongTime String.Format("{0:D}", dt); // "Sunday, March 09, 2008" LongDate String.Format("{0:f}", dt); // "Sunday, March 09, 2008 4:05 PM" LongDate+ShortTime String.Format("{0:F}", dt); // "Sunday, March 09, 2008 4:05:07 PM" FullDateTime String.Format("{0:g}", dt); // "3/9/2008 4:05 PM" ShortDate+ShortTime String.Format("{0:G}", dt); // "3/9/2008 4:05:07 PM" ShortDate+LongTime String.Format("{0:m}", dt); // "March 09" MonthDay String.Format("{0:y}", dt); // "March, 2008" YearMonth String.Format("{0:r}", dt); // "Sun, 09 Mar 2008 16:05:07 GMT" RFC1123 String.Format("{0:s}", dt); // "2008-03-09T16:05:07" SortableDateTime String.Format("{0:u}", dt); // "2008-03-09 16:05:07Z" UniversalSortableDateTime

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• Algorithmia Source Code released on CodePlex

  - by FransBouma

  Following the release of our BCL Extensions Library on CodePlex, we have now released the source-code of Algorithmia on CodePlex! Algorithmia is an algorithm and data-structures library for .NET 3.5 or higher and is one of the pillars LLBLGen Pro v3's designer is built on. The library contains many data-structures and algorithms, and the source-code is well documented and commented, often with links to official descriptions and papers of the algorithms and data-structures implemented. The source-code is shared using Mercurial on CodePlex and is licensed under the friendly BSD2 license. User documentation is not available at the moment but will be added soon. One of the main design goals of Algorithmia was to create a library which contains implementations of well-known algorithms which weren't already implemented in .NET itself. This way, more developers out there can enjoy the results of many years of what the field of Computer Science research has delivered. Some algorithms and datastructures are known in .NET but are re-implemented because the implementation in .NET isn't efficient for many situations or lacks features. An example is the linked list in .NET: it doesn't have an O(1) concat operation, as every node refers to the containing LinkedList object it's stored in. This is bad for algorithms which rely on O(1) concat operations, like the Fibonacci heap implementation in Algorithmia. Algorithmia therefore contains a linked list with an O(1) concat feature. The following functionality is available in Algorithmia: Command, Command management. This system is usable to build a fully undo/redo aware system by building your object graph using command-aware classes. The Command pattern is implemented using a system which allows transparent undo-redo and command grouping so you can use it to make a class undo/redo aware and set properties, use its contents without using commands at all. The Commands namespace is the namespace to start. Classes you'd want to look at are CommandifiedMember, CommandifiedList and KeyedCommandifiedList. See the CommandQueueTests in the test project for examples. Graphs, Graph algorithms. Algorithmia contains a sophisticated graph class hierarchy and algorithms implemented onto them: non-directed and directed graphs, as well as a subgraph view class, which can be used to create a view onto an existing graph class which can be self-maintaining. Algorithms include transitive closure, topological sorting and others. A feature rich depth-first search (DFS) crawler is available so DFS based algorithms can be implemented quickly. All graph classes are undo/redo aware, as they can be set to be 'commandified'. When a graph is 'commandified' it will do its housekeeping through commands, which makes it fully undo-redo aware, so you can remove, add and manipulate the graph and undo/redo the activity automatically without any extra code. If you define the properties of the class you set as the vertex type using CommandifiedMember, you can manipulate the properties of vertices and the graph contents with full undo/redo functionality without any extra code. Heaps. Heaps are data-structures which have the largest or smallest item stored in them always as the 'root'. Extracting the root from the heap makes the heap determine the next in line to be the 'maximum' or 'minimum' (max-heap vs. min-heap, all heaps in Algorithmia can do both). Algorithmia contains various heaps, among them an implementation of the Fibonacci heap, one of the most efficient heap datastructures known today, especially when you want to merge different instances into one. Priority queues. Priority queues are specializations of heaps. Algorithmia contains a couple of them. Sorting. What's an algorithm library without sort algorithms? Algorithmia implements a couple of sort algorithms which sort the data in-place. This aspect is important in situations where you want to sort the elements in a buffer/list/ICollection in-place, so all data stays in the data-structure it already is stored in. PropertyBag. It re-implements Tony Allowatt's original idea in .NET 3.5 specific syntax, which is to have a generic property bag and to be able to build an object in code at runtime which can be bound to a property grid for editing. This is handy for when you have data / settings stored in XML or other format, and want to create an editable form of it without creating many editors. IEditableObject/IDataErrorInfo implementations. It contains default implementations for IEditableObject and IDataErrorInfo (EditableObjectDataContainer for IEditableObject and ErrorContainer for IDataErrorInfo), which make it very easy to implement these interfaces (just a few lines of code) without having to worry about bookkeeping during databinding. They work seamlessly with CommandifiedMember as well, so your undo/redo aware code can use them out of the box. EventThrottler. It contains an event throttler, which can be used to filter out duplicate events in an event stream coming into an observer from an event. This can greatly enhance performance in your UI without needing to do anything other than hooking it up so it's placed between the event source and your real handler. If your UI is flooded with events from data-structures observed by your UI or a middle tier, you can use this class to filter out duplicates to avoid redundant updates to UI elements or to avoid having observers choke on many redundant events. Small, handy stuff. A MultiValueDictionary, which can store multiple unique values per key, instead of one with the default Dictionary, and is also merge-aware so you can merge two into one. A Pair class, to quickly group two elements together. Multiple interfaces for helping with building a de-coupled, observer based system, and some utility extension methods for the defined data-structures. We regularly update the library with new code. If you have ideas for new algorithms or want to share your contribution, feel free to discuss it on the project's Discussions page or send us a pull request. Enjoy!

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• HR According to Batman

  - by D'Arcy Lussier

  Any idea who that guy is running alongside the Caped Crusader? That’s Nightwing, but you may know him as Robin…well, the first Robin anyway. There were actually like 5 Robin’s according to Wikipedia: Dick Grayson, the original, who’s parents were circus performers killed by a gangster. Jason Todd, who was caught trying to steal tires off of the Batmobile. Tim Drake, who saw Dick’s parents die and figured out who Batman and Robin were. and a few others that get into recent time travel/altered reality storylines. What does this have to do with HR? Well, it somewhat ties in with an article by Alex Papadimoulis from 2008. In the article he talks about the “Cravath System”. The Craveth system was developed by a law firm called Cravath, Swaine & Moore back in the 19th century. In a nutshell, they believed in hiring the best and brightest straight out of school. These aspiring lawyers would then begin a fight for survival in the firm, with the strong surviving. In what’s termed the “Up and Out” rule, employees needed to be promoted within 3 years or leave the company. They should achieve partner within 7 – 8 years and no later than 10 after initially coming on board (read all about the system on Wikipedia here). Back to Alex’s article, he quotes from a book published in 1947 about the lawfirm: Under the “Cravath system” of taking a substantial number of men annually and keeping a current constantly moving up in the office, and its philosophy of tenure, men are constantly leaving… it is often difficult to keep the best men long enough to determine whether they shall be made partners, for Cravath-trained men are always in demand, usually at premium salaries. And so we see a pattern forming here: 1. Hire a whole whack of smart college graduates 2. Put them to work 3. The ones that stick around should move up the ladder. The ones that don’t stick around served the company well and left to expound the quality of the Cravath firm. Those that didn’t fall into either of those categories were just let go. There’s some interesting undercurrents to these ideas. If you stick around, you better keep your feet moving! I was at a Microsoft shindig a few months back, and was talking to a Microsoft employee. He shared that at MS you have 5 years to achieve a “senior” position within the company. Once you hit that mark, you can stay there for the rest of your career (he told about a guy who’s a “senior” developer and has been for the last 20+ years working on audio drivers for Windows), but you *must* hit that mark within the timeframe. What we see with Microsoft is Cravath’s system in action, whether intentional or not: bring in smart young people and see which ones stick. You need to give people something to work towards. Saying “You must reach this level or else!” is one way to look at it. The other way is to see achieving a higher rank in the organization as something for ambitious employees to reach towards. It’s important for an organization to always have the next generation of executives waiting in the wings, and unless you’re encouraging that early on you may find yourself in a position of needing to fill positions that nobody has been working towards. Now, you might suggest that this isn’t that big of a deal because you could just hire someone from outside the organization, but the Cravath system holds to the tenet of promoting internally; develop your own talent, since your business is the best place for the future leadership to learn teh business from. It’s OK for people to quit. Alex’s article really drives this point home, but its worth noting here also: its OK for your people to quit. In fact its inevitable…and more inevitable that it’ll be good people that leave. Some will stay and work towards the internal awards of promotion, but a number will get experience, serve the organization well, and then move on to something else. This should be expected and treated as a natural business occurrence. The idea of an alumni of an organization begins to come into play here: “That guy used to work for <insert company here>”. There’s a benefit in that: those best and brightest will be drawn to your organization and your reputation will permeate your market through former staff that are sought after because of how well you nurtured them. The Batman Hook All of this brings us back to Batman and his HR practice: when Dick decided he’d had enough of the Robin schtick, he quit and became his own…but he was always associated with Batman and people understood where his training had come from. To the Dark Knight’s credit, he continued training partners under the Robin brand. Luckily he didn’t have to worry about firing any of them (the ship sort of sails when you reveal a secret identity), although there was that unfortunate “quitting” of the second Robin when the Joker blew him up…but regardless, we see the Cravath system at work: bring in talent, expect great things, and be ok with whatever they decide for their careers. It’s an interesting way to approach HR, and luckily for us our business isn’t as dangerous or over-the-top as the caped crusader’s.

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• RIDC Accelerator for Portal

  - by Stefan Krantz

  What is RIDC?Remote IntraDoc Client is a Java enabled API that leverages simple transportation protocols like Socket, HTTP and JAX/WS to execute content service operations in WebCenter Content Server. Each operation by design in the Content Server will execute stateless and return a complete result of the request. Each request object simply specifies the in a Map format (key and value pairs) what service to call and what parameters settings to apply. The result responded with will be built on the same Map format (key and value pairs). The possibilities with RIDC is endless since you can consume any available service (even custom made ones), RIDC can be executed from any Java SE application that has any WebCenter Content Services needs. WebCenter Portal and the example Accelerator RIDC adapter frameworkWebCenter Portal currently integrates and leverages WebCenter Content Services to enable available use cases in the portal today, like Content Presenter and Doc Lib. However the current use cases only covers few of the scenarios that the Content Server has to offer, in addition to the existing use cases it is not rare that the customer requirements requires additional steps and functionality that is provided by WebCenter Content but not part of the use cases from the WebCenter Portal.The good news to this is RIDC, the second good news is that WebCenter Portal already leverages the RIDC and has a connection management framework in place. The million dollar question here is how can I leverage this infrastructure for my custom use cases. Oracle A-Team has during its interactions produced a accelerator adapter framework that will reuse and leverage the existing connections provisioned in the webcenter portal application (works for WebCenter Spaces as well), as well as a very comprehensive design patter to minimize the work involved when exposing functionality. Let me introduce the RIDCCommon framework for accelerating WebCenter Content consumption from WebCenter Portal including Spaces. How do I get started?Through a few easy steps you will be on your way, Extract the zip file RIDCCommon.zip to the WebCenter Portal Application file structure (PortalApp) Open you Portal Application in JDeveloper (PS4/PS5) select to open the project in your application - this will add the project as a member of the application Update the Portal project dependencies to include the new RIDCCommon project Make sure that you WebCenter Content Server connection is marked as primary (a checkbox at the top of the connection properties form) You should by this stage have a similar structure in your JDeveloper Application Project Portal Project PortalWebAssets Project RIDCCommon Since the API is coming with some example operations that has already been exposed as DataControl actions, if you open Data Controls accordion you should see following: How do I implement my own operation? Create a new Java Class in for example com.oracle.ateam.portal.ridc.operation call it (GetDocInfoOperation) Extend the abstract class com.oracle.ateam.portal.ridc.operation.RIDCAbstractOperation and implement the interface com.oracle.ateam.portal.ridc.operation.IRIDCOperation The only method you actually are required to implement is execute(RIDCManager, IdcClient, IdcContext) The best practice to set object references for the operation is through the Constructor, example below public GetDocInfoOperation(String dDocName)By leveraging the constructor you can easily force the implementing class to pass right information, you can also overload the Constructor with more or less parameters as required Implement the execute method, the work you supposed to execute here is creating a new request binder and retrieve a response binder with the information in the request binder.In this case the dDocName for which we want the DocInfo Secondly you have to process the response binder by extracting the information you need from the request and restore this information in a simple POJO Java BeanIn the example below we do this in private void processResult(DataBinder responseData) - the new SearchDataObject is a Member of the GetDocInfoOperation so we can return this from a access method. Since the RIDCCommon API leverage template pattern for the operations you are now required to add a method that will enable access to the result after the execution of the operationIn the example below we added the method public SearchDataObject getDataObject() - this method returns the pre processed SearchDataObject from the execute method  This is it, as you can see on the code below you do not need more than 32 lines of very simple code 1: public class GetDocInfoOperation extends RIDCAbstractOperation implements IRIDCOperation { 2: private static final String DOC_INFO_BY_NAME = "DOC_INFO_BY_NAME"; 3: private String dDocName = null; 4: private SearchDataObject sdo = null; 5: 6: public GetDocInfoOperation(String dDocName) { 7: super(); 8: this.dDocName = dDocName; 9: } 10:   11: public boolean execute(RIDCManager manager, IdcClient client, 12: IdcContext userContext) throws Exception { 13: DataBinder dataBinder = createNewRequestBinder(DOC_INFO_BY_NAME); 14: dataBinder.putLocal(DocumentAttributeDef.NAME.getName(), dDocName); 15: 16: DataBinder responseData = getResponseBinder(dataBinder); 17: processResult(responseData); 18: return true; 19: } 20: 21: private void processResult(DataBinder responseData) { 22: DataResultSet rs = responseData.getResultSet("DOC_INFO"); 23: for(DataObject dobj : rs.getRows()) { 24: this.sdo = new SearchDataObject(dobj); 25: } 26: super.setMessage(responseData.getLocal(ATTR_MESSAGE)); 27: } 28: 29: public SearchDataObject getDataObject() { 30: return this.sdo; 31: } 32: } How do I execute my operation? In the previous section we described how to create a operation, so by now you should be ready to execute the operation Step one either add a method to the class  com.oracle.ateam.portal.datacontrol.ContentServicesDC or a class of your own choiceRemember the RIDCManager is a very light object and can be created where needed Create a method signature look like this public SearchDataObject getDocInfo(String dDocName) throws Exception In the method body - create a new instance of GetDocInfoOperation and meet the constructor requirements by passing the dDocNameGetDocInfoOperation docInfo = new GetDocInfoOperation(dDocName) Execute the operation via the RIDCManager instance rMgr.executeOperation(docInfo) Return the result by accessing it from the executed operationreturn docInfo.getDataObject() 1: private RIDCManager rMgr = null; 2: private String lastOperationMessage = null; 3:   4: public ContentServicesDC() { 5: super(); 6: this.rMgr = new RIDCManager(); 7: } 8: .... 9: public SearchDataObject getDocInfo(String dDocName) throws Exception { 10: GetDocInfoOperation docInfo = new GetDocInfoOperation(dDocName); 11: boolean boolVal = rMgr.executeOperation(docInfo); 12: lastOperationMessage = docInfo.getMessage(); 13: return docInfo.getDataObject(); 14: }   Get the binaries! The enclosed code in a example that can be used as a reference on how to consume and leverage similar use cases, user has to guarantee appropriate quality and support.  Download link: https://blogs.oracle.com/ATEAM_WEBCENTER/resource/stefan.krantz/RIDCCommon.zip RIDC API Referencehttp://docs.oracle.com/cd/E23943_01/apirefs.1111/e17274/toc.htm

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• Parallelism in .NET – Part 17, Think Continuations, not Callbacks

  - by Reed

  In traditional asynchronous programming, we’d often use a callback to handle notification of a background task’s completion.  The Task class in the Task Parallel Library introduces a cleaner alternative to the traditional callback: continuation tasks. Asynchronous programming methods typically required callback functions.  For example, MSDN’s Asynchronous Delegates Programming Sample shows a class that factorizes a number.  The original method in the example has the following signature: public static bool Factorize(int number, ref int primefactor1, ref int primefactor2) { //... .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } However, calling this is quite “tricky”, even if we modernize the sample to use lambda expressions via C# 3.0.  Normally, we could call this method like so: int primeFactor1 = 0; int primeFactor2 = 0; bool answer = Factorize(10298312, ref primeFactor1, ref primeFactor2); Console.WriteLine("{0}/{1} [Succeeded {2}]", primeFactor1, primeFactor2, answer); If we want to make this operation run in the background, and report to the console via a callback, things get tricker.  First, we need a delegate definition: public delegate bool AsyncFactorCaller( int number, ref int primefactor1, ref int primefactor2); Then we need to use BeginInvoke to run this method asynchronously: int primeFactor1 = 0; int primeFactor2 = 0; AsyncFactorCaller caller = new AsyncFactorCaller(Factorize); caller.BeginInvoke(10298312, ref primeFactor1, ref primeFactor2, result => { int factor1 = 0; int factor2 = 0; bool answer = caller.EndInvoke(ref factor1, ref factor2, result); Console.WriteLine("{0}/{1} [Succeeded {2}]", factor1, factor2, answer); }, null); This works, but is quite difficult to understand from a conceptual standpoint.  To combat this, the framework added the Event-based Asynchronous Pattern, but it isn’t much easier to understand or author. Using .NET 4’s new Task<T> class and a continuation, we can dramatically simplify the implementation of the above code, as well as make it much more understandable.  We do this via the Task.ContinueWith method.  This method will schedule a new Task upon completion of the original task, and provide the original Task (including its Result if it’s a Task<T>) as an argument.  Using Task, we can eliminate the delegate, and rewrite this code like so: var background = Task.Factory.StartNew( () => { int primeFactor1 = 0; int primeFactor2 = 0; bool result = Factorize(10298312, ref primeFactor1, ref primeFactor2); return new { Result = result, Factor1 = primeFactor1, Factor2 = primeFactor2 }; }); background.ContinueWith(task => Console.WriteLine("{0}/{1} [Succeeded {2}]", task.Result.Factor1, task.Result.Factor2, task.Result.Result)); This is much simpler to understand, in my opinion.  Here, we’re explicitly asking to start a new task, then continue the task with a resulting task.  In our case, our method used ref parameters (this was from the MSDN Sample), so there is a little bit of extra boiler plate involved, but the code is at least easy to understand. That being said, this isn’t dramatically shorter when compared with our C# 3 port of the MSDN code above.  However, if we were to extend our requirements a bit, we can start to see more advantages to the Task based approach.  For example, supposed we need to report the results in a user interface control instead of reporting it to the Console.  This would be a common operation, but now, we have to think about marshaling our calls back to the user interface.  This is probably going to require calling Control.Invoke or Dispatcher.Invoke within our callback, forcing us to specify a delegate within the delegate.  The maintainability and ease of understanding drops.  However, just as a standard Task can be created with a TaskScheduler that uses the UI synchronization context, so too can we continue a task with a specific context.  There are Task.ContinueWith method overloads which allow you to provide a TaskScheduler.  This means you can schedule the continuation to run on the UI thread, by simply doing: Task.Factory.StartNew( () => { int primeFactor1 = 0; int primeFactor2 = 0; bool result = Factorize(10298312, ref primeFactor1, ref primeFactor2); return new { Result = result, Factor1 = primeFactor1, Factor2 = primeFactor2 }; }).ContinueWith(task => textBox1.Text = string.Format("{0}/{1} [Succeeded {2}]", task.Result.Factor1, task.Result.Factor2, task.Result.Result), TaskScheduler.FromCurrentSynchronizationContext()); This is far more understandable than the alternative.  By using Task.ContinueWith in conjunction with TaskScheduler.FromCurrentSynchronizationContext(), we get a simple way to push any work onto a background thread, and update the user interface on the proper UI thread.  This technique works with Windows Presentation Foundation as well as Windows Forms, with no change in methodology.

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