Search Results

Search found 5810 results on 233 pages for 'staff of geeks'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 30/233 | < Previous Page | 26 27 28 29 30 31 32 33 34 35 36 37  | Next Page >

  • Craftsmanship Tour: Day 3 &amp; 4 8th Light

    - by Liam McLennan
    Thursday morning the Illinois public transport system came through for me again. I took the Metra train north from Union Station (which was seething with inbound commuters) to Prairie Crossing (Libertyville). At Prairie Crossing I met Paul and Justin from 8th Light and then Justin drove us to the office. The 8th Light office is in an small business park, in a semi-rural area, surrounded by ponds. Upstairs there are two spacious, open areas for developers. At one end of the floor is Doug Bradbury’s walk-and-code station; a treadmill with a desk and computer so that a developer can get exercise at work. At the other end of the floor is a hammock. This irregular office furniture is indicative of the 8th Light philosophy, to pursue excellence without being limited by conventional wisdom. 8th Light have a wall covered in posters, each illustrating one person’s software craftsmanship journey. The posters are a fascinating visualisation of the similarities and differences between each of our progressions. The first thing I did Thursday morning was to create my own poster and add it to the wall. Over two days at 8th Light I did some pairing with the 8th Lighters and we shared thoughts on software development. I am not accustomed to such a progressive and enlightened environment and I found the experience inspirational. At 8th Light TDD, clean code, pairing and kaizen are deeply ingrained in the culture. Friday, during lunch, 8th Light hosted a ‘lunch and learn’ event. Paul Pagel lead us through a coding exercise using micro-pomodori. We worked in pairs, focusing on the pedagogy of pair programming and TDD. After lunch I recorded this interview with Paul Pagel and Justin Martin. We discussed 8th light, craftsmanship, apprenticeships and the limelight framework. Interview with Paul Pagel and Justin Martin My time at Didit, Obtiva and 8th Light has convinced me that I need to give up some of my independence and go back to working in a team. Craftsmen advance their skills by learning from each other, and I can’t do that working at home by myself. The challenge is finding the right team, and becoming a part of it.

    Read the article

  • A few things I learned regarding Azure billing policies

    - by Vincent Grondin
    An hour of small computing time: 0,12$ per hour A Gig of storage in the cloud: 0,15$ per hour 1 Gig of relational database using Azure SQL: 9,99$  per month A Visual Studio Professional with MSDN Premium account: 2500$ per year Winning an MSDN Professional account that comes preloaded with 750 free hours of Azure per month:  PRICELESS !!!      But was it really free???? Hmmm… Let’s see.....   Here's a few things I learned regarding Azure billing policies when I attended a promotional training at Microsoft last week...   1)  An instance deployed in the cloud really means whatever you upload in there... it doesn't matter if it's in STAGING OR PRODUCTION!!!!   Your MSDN account comes with 750 free hours of small computing time per month which should be enough hours per month for one instance of one application deployed in the cloud...  So we're cool, the application you run in the cloud doesn't cost you a penny....  BUT the one that's in staging is still consuming time!!!   So if you don’t want to end up having to pay 42$ at the end of the month on your credit card like this happened to a friend of mine, DELETE them staging applications once you’ve put them in production! This also applies to the instance count you can modify in the configuration file… So stop and think before you decide you want to spawn 50 of those hello world apps  .     2) If you have an MSDN account, then you have the promotional 750 hours of Azure credits per month and can use the Azure credits to explore the Cloud! But be aware, this promotion ends in 8 months (maybe more like 7 now) and then you will most likely go back to the standard 250 hours of Azure credits. If you do not delete your applications by then, you’ll get billed for the extra hours, believe me…   There is a switch that you can toggle and which will STOP your automatic enrollment after the promotion and prevent you from renewing the Azure Account automatically. Yes the default setting is to automatically renew your account and remember, you entered your credit card information in the registration process so, yes, you WILL be billed…  Go disable that ASAP    Log into your account, go to “Windows Azure Platform” then click the “Subscriptions” tab and on the right side, you’ll see a drop down with different “Actions” into it… Choose “Opt out of auto renew” and, NOW you’re safe…   Still, this is a great offer by Microsoft and I think everyone that has a chance should play a bit with Azure to get to know this technology a bit more...     Happy Cloud Computing All

    Read the article

  • Silverlight Cream Top Posted Authors June to November, 2010

    - by Dave Campbell
    It's just past the first of December, but I've been busy and it's now time to recognize devs that have a large number of posts in Silverlight Cream. Ground Rules I pick what posts are on the blog Only posts that go in the database are included The author has to appear in SC at least 4 of the 6 months considered I averaged the monthly posts and am only showing Authors with an average greater than 1. Here are the Top Posted Authors at Silverlight Cream for June 1, 2010 through November 30, 2010: It is my intention to post a new list sometime shortly after the 1st of every month to recognize the top posted in the previous 6 months, so next up is January 1! Some other metrics for Silverlight Cream: At the time of this posting there are 7087 articles aggregated and searchable by partial Author, partial Title, keywords (in the synopsis), or partial URL. There are also 116 tags by which the articles can be searched. At the time of this posting there are 664 articles tagged wp7dev. Stay in the 'Light!

    Read the article

  • Performance considerations for common SQL queries

    - by Jim Giercyk
    Originally posted on: http://geekswithblogs.net/NibblesAndBits/archive/2013/10/16/performance-considerations-for-common-sql-queries.aspxSQL offers many different methods to produce the same results.  There is a never-ending debate between SQL developers as to the “best way” or the “most efficient way” to render a result set.  Sometimes these disputes even come to blows….well, I am a lover, not a fighter, so I decided to collect some data that will prove which way is the best and most efficient.  For the queries below, I downloaded the test database from SQLSkills:  http://www.sqlskills.com/sql-server-resources/sql-server-demos/.  There isn’t a lot of data, but enough to prove my point: dbo.member has 10,000 records, and dbo.payment has 15,554.  Our result set contains 6,706 records. The following queries produce an identical result set; the result set contains aggregate payment information for each member who has made more than 1 payment from the dbo.payment table and the first and last name of the member from the dbo.member table.   /*************/ /* Sub Query  */ /*************/ SELECT  a.[Member Number] ,         m.lastname ,         m.firstname ,         a.[Number Of Payments] ,         a.[Average Payment] ,         a.[Total Paid] FROM    ( SELECT    member_no 'Member Number' ,                     AVG(payment_amt) 'Average Payment' ,                     SUM(payment_amt) 'Total Paid' ,                     COUNT(Payment_No) 'Number Of Payments'           FROM      dbo.payment           GROUP BY  member_no           HAVING    COUNT(Payment_No) > 1         ) a         JOIN dbo.member m ON a.[Member Number] = m.member_no         /***************/ /* Cross Apply  */ /***************/ SELECT  ca.[Member Number] ,         m.lastname ,         m.firstname ,         ca.[Number Of Payments] ,         ca.[Average Payment] ,         ca.[Total Paid] FROM    dbo.member m         CROSS APPLY ( SELECT    member_no 'Member Number' ,                                 AVG(payment_amt) 'Average Payment' ,                                 SUM(payment_amt) 'Total Paid' ,                                 COUNT(Payment_No) 'Number Of Payments'                       FROM      dbo.payment                       WHERE     member_no = m.member_no                       GROUP BY  member_no                       HAVING    COUNT(Payment_No) > 1                     ) ca /********/                    /* CTEs  */ /********/ ; WITH    Payments           AS ( SELECT   member_no 'Member Number' ,                         AVG(payment_amt) 'Average Payment' ,                         SUM(payment_amt) 'Total Paid' ,                         COUNT(Payment_No) 'Number Of Payments'                FROM     dbo.payment                GROUP BY member_no                HAVING   COUNT(Payment_No) > 1              ),         MemberInfo           AS ( SELECT   p.[Member Number] ,                         m.lastname ,                         m.firstname ,                         p.[Number Of Payments] ,                         p.[Average Payment] ,                         p.[Total Paid]                FROM     dbo.member m                         JOIN Payments p ON m.member_no = p.[Member Number]              )     SELECT  *     FROM    MemberInfo /************************/ /* SELECT with Grouping   */ /************************/ SELECT  p.member_no 'Member Number' ,         m.lastname ,         m.firstname ,         COUNT(Payment_No) 'Number Of Payments' ,         AVG(payment_amt) 'Average Payment' ,         SUM(payment_amt) 'Total Paid' FROM    dbo.payment p         JOIN dbo.member m ON m.member_no = p.member_no GROUP BY p.member_no ,         m.lastname ,         m.firstname HAVING  COUNT(Payment_No) > 1   We can see what is going on in SQL’s brain by looking at the execution plan.  The Execution Plan will demonstrate which steps and in what order SQL executes those steps, and what percentage of batch time each query takes.  SO….if I execute all 4 of these queries in a single batch, I will get an idea of the relative time SQL takes to execute them, and how it renders the Execution Plan.  We can settle this once and for all.  Here is what SQL did with these queries:   Not only did the queries take the same amount of time to execute, SQL generated the same Execution Plan for each of them.  Everybody is right…..I guess we can all finally go to lunch together!  But wait a second, I may not be a fighter, but I AM an instigator.     Let’s see how a table variable stacks up.  Here is the code I executed: /********************/ /*  Table Variable  */ /********************/ DECLARE @AggregateTable TABLE     (       member_no INT ,       AveragePayment MONEY ,       TotalPaid MONEY ,       NumberOfPayments MONEY     ) INSERT  @AggregateTable         SELECT  member_no 'Member Number' ,                 AVG(payment_amt) 'Average Payment' ,                 SUM(payment_amt) 'Total Paid' ,                 COUNT(Payment_No) 'Number Of Payments'         FROM    dbo.payment         GROUP BY member_no         HAVING  COUNT(Payment_No) > 1   SELECT  at.member_no 'Member Number' ,         m.lastname ,         m.firstname ,         at.NumberOfPayments 'Number Of Payments' ,         at.AveragePayment 'Average Payment' ,         at.TotalPaid 'Total Paid' FROM    @AggregateTable at         JOIN dbo.member m ON m.member_no = at.member_no In the interest of keeping things in groupings of 4, I removed the last query from the previous batch and added the table variable query.  Here’s what I got:     Since we first insert into the table variable, then we read from it, the Execution Plan renders 2 steps.  BUT, the combination of the 2 steps is only 22% of the batch.  It is actually faster than the other methods even though it is treated as 2 separate queries in the Execution Plan.  The argument I often hear against Table Variables is that SQL only estimates 1 row for the table size in the Execution Plan.  While this is true, the estimate does not come in to play until you read from the table variable.  In this case, the table variable had 6,706 rows, but it still outperformed the other queries.  People argue that table variables should only be used for hash or lookup tables.  The fact is, you have control of what you put IN to the variable, so as long as you keep it within reason, these results suggest that a table variable is a viable alternative to sub-queries. If anyone does volume testing on this theory, I would be interested in the results.  My suspicion is that there is a breaking point where efficiency goes down the tubes immediately, and it would be interesting to see where the threshold is. Coding SQL is a matter of style.  If you’ve been around since they introduced DB2, you were probably taught a little differently than a recent computer science graduate.  If you have a company standard, I strongly recommend you follow it.    If you do not have a standard, generally speaking, there is no right or wrong answer when talking about the efficiency of these types of queries, and certainly no hard-and-fast rule.  Volume and infrastructure will dictate a lot when it comes to performance, so your results may vary in your environment.  Download the database and try it!

    Read the article

  • Silverlight Cream for March 08, 2010 -- #809

    - by Dave Campbell
    In this Issue: Michael Washington, Tim Greenfield, Bobby Diaz(-2-), Glenn Block(-2-), Nikhil Kothari, Jianqiang Bao(-2-), and Christopher Bennage. Shoutouts: Adam Kinney announced a Big update for the Project Rosetta site today Arpit Gupta has opened a new blog with a great logo: I think therefore I am dangerous :) From SilverlightCream.com: DotNetNuke Silverlight Traffic Module If it's DNN and Silverlight, it has to be my buddy Michael Washington :) ... Michael has combined those stunning gauges you've seen with website traffic... just too cool!... grab the code and display yours too! Cool demonstration of Silverlight VideoBrush This is a no-code post by Tim Greenfield, but I like the UX on this Jigsaw Puzzle page... and you can make your own. Introducing the Earthquake Locator – A Bing Maps Silverlight Application, part 1 Bobby Diaz has an informative post up on combining earthquake data with BingMaps in Silverlight 3... check it out, the grab the recently posted Live Demo and Source Code Adding Volcanos and Options - Earthquake Locator, part 2 Bobby Diaz also added volcanic activity to his earthquake BinMaps app, and updated the downloadable code and live demo. Building Hello MEF – Part IV – DeploymentCatalog Glenn Block posted a pair of MEF posts yesterday... made me think I missed one :) .. the first one is about the DeploymentCatalog. Note he is going to be using the CodePlex bits in his posts. Building HelloMEF – Part V – Refactoring to ViewModel Glenn Block's part V is about MEF and MVVM -- no, really! ... he is refactoring MVVM into the app with a nod to Josh Smith and Laurent Bugnion... get your head around this... The Case for ViewModel Nikhil Kothari has a post up about the ViewModel, and how it facilitates designer/developer workflow, jumpstarts development, improves scaling, and makes asynch programming development simpler MMORPG programming in Silverlight Tutorial (12)Map Instance (Part I) Jianqiang Bao has part 12 of his MMORPG game up... this one is showing how to deal with obstuctions on maps. MMORPG programming in Silverlight Tutorial (13)Perfect moving mechanism Jianqiang Bao also has part 13 up, and this second one is about sprite movement around the obstructions. 1 Simple Step for Commanding in Silverlight Christopher Bennage blogged about Commanding in Silverlight, he begins with a blog post about commands in Silverlight 4 then goes on to demonstrate the Caliburn way of doing commanding. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    MIX10

    Read the article

  • First look at the cloud with Google App Engine and Udacity

    - by Ken Hortsch
    Udacity is free online university and offers a CS253 intro to web development class.  Since I am currently a web developer/architect in ASP.Net (and recent project has brought me back to Java) it is a bit light.  However, it does offer me a nice problem set and my first exposure to writing cloud apps with GAE and Google Datastore. Steve Huffman, who developed reddit, is the instructor and does offer nice real-life stories.  Give it a look.

    Read the article

  • C# tip: do not use “is” type, if you will need cast “as” later

    - by Michael Freidgeim
    We have a debate with one of my collegues, is it agood style to check, if the object of particular style, and then cast  as this  type. The perfect answer of Jon Skeet   and answers in Cast then check or check then cast? confirmed my point.//good    var coke = cola as CocaCola;    if (coke != null)    {        // some unique coca-cola only code    }    //worse    if (cola is CocaCola)    {        var coke =  cola as CocaCola;        // some unique coca-cola only code here.    }

    Read the article

  • TestDriven.NET - Free unit test tool for Visual Studio

    - by Guilherme Cardoso
    Developers that use unit testing are familiar with Resharper and his plugin for Unit Testing. For those that like me, don't have a great pc hardware (Pentium 4, 3ghz, 1GB ram) the Resharper can be really slow, and affect the performance of pc. That's why i use TestDriven.NET TestDriven.NET is a freeware license tool (there are others licenses for this product) that gives us the possibility to run unit tests with this plugin, that's integrated with Visual Studio. You can check some screenshots here: http://www.testdriven.net/Screenshots.aspx It's compatible with: NUnit, MbUnit, MSTest, NCover, Reflector, TypeMock, dotTrace and MSBee. More information and free download here: http://www.testdriven.net

    Read the article

  • Converting Openfire IM datetime values in SQL Server to / from VARCHAR(15) and DATETIME data types

    - by Brian Biales
    A client is using Openfire IM for their users, and would like some custom queries to audit user conversations (which are stored by Openfire in tables in the SQL Server database). Because Openfire supports multiple database servers and multiple platforms, the designers chose to store all date/time stamps in the database as 15 character strings, which get converted to Java Date objects in their code (Openfire is written in Java).  I did some digging around, and, so I don't forget and in case someone else will find this useful, I will put the simple algorithms here for converting back and forth between SQL DATETIME and the Java string representation. The Java string representation is the number of milliseconds since 1/1/1970.  SQL Server's DATETIME is actually represented as a float, the value being the number of days since 1/1/1900, the portion after the decimal point representing the hours/minutes/seconds/milliseconds... as a fractional part of a day.  Try this and you will see this is true:     SELECT CAST(0 AS DATETIME) and you will see it returns the date 1/1/1900. The difference in days between SQL Server's 0 date of 1/1/1900 and the Java representation's 0 date of 1/1/1970 is found easily using the following SQL:   SELECT DATEDIFF(D, '1900-01-01', '1970-01-01') which returns 25567.  There are 25567 days between these dates. So to convert from the Java string to SQL Server's date time, we need to convert the number of milliseconds to a floating point representation of the number of days since 1/1/1970, then add the 25567 to change this to the number of days since 1/1/1900.  To convert to days, you need to divide the number by 1000 ms/s, then by  60 seconds/minute, then by 60 minutes/hour, then by 24 hours/day.  Or simply divide by 1000*60*60*24, or 86400000.   So, to summarize, we need to cast this string as a float, divide by 86400000 milliseconds/day, then add 25567 days, and cast the resulting value to a DateTime.  Here is an example:   DECLARE @tmp as VARCHAR(15)   SET @tmp = '1268231722123'   SELECT @tmp as JavaTime, CAST((CAST(@tmp AS FLOAT) / 86400000) + 25567 AS DATETIME) as SQLTime   To convert from SQL datetime back to the Java time format is not quite as simple, I found, because floats of that size do not convert nicely to strings, they end up in scientific notation using the CONVERT function or CAST function.  But I found a couple ways around that problem. You can convert a date to the number of  seconds since 1/1/1970 very easily using the DATEDIFF function, as this value fits in an Int.  If you don't need to worry about the milliseconds, simply cast this integer as a string, and then concatenate '000' at the end, essentially multiplying this number by 1000, and making it milliseconds since 1/1/1970.  If, however, you do care about the milliseconds, you will need to use DATEPART to get the milliseconds part of the date, cast this integer to a string, and then pad zeros on the left to make sure this is three digits, and concatenate these three digits to the number of seconds string above.  And finally, I discovered by casting to DECIMAL(15,0) then to VARCHAR(15), I avoid the scientific notation issue.  So here are all my examples, pick the one you like best... First, here is the simple approach if you don't care about the milliseconds:   DECLARE @tmp as VARCHAR(15)   DECLARE @dt as DATETIME   SET @dt = '2010-03-10 14:35:22.123'   SET @tmp = CAST(DATEDIFF(s, '1970-01-01 00:00:00' , @dt) AS VARCHAR(15)) + '000'   SELECT @tmp as JavaTime, @dt as SQLTime If you want to keep the milliseconds:   DECLARE @tmp as VARCHAR(15)   DECLARE @dt as DATETIME   DECLARE @ms as int   SET @dt = '2010-03-10 14:35:22.123'   SET @ms as DATEPART(ms, @dt)   SET @tmp = CAST(DATEDIFF(s, '1970-01-01 00:00:00' , @dt) AS VARCHAR(15))           + RIGHT('000' + CAST(@ms AS VARCHAR(3)), 3)   SELECT @tmp as JavaTime, @dt as SQLTime Or, in one fell swoop:   DECLARE @dt as DATETIME   SET @dt = '2010-03-10 14:35:22.123'   SELECT @dt as SQLTime     , CAST(DATEDIFF(s, '1970-01-01 00:00:00' , @dt) AS VARCHAR(15))           + RIGHT('000' + CAST( DATEPART(ms, @dt) AS VARCHAR(3)), 3) as JavaTime   And finally, a way to simply reverse the math used converting from Java date to SQL date. Note the parenthesis - watch out for operator precedence, you want to subtract, then multiply:   DECLARE @dt as DATETIME   SET @dt = '2010-03-10 14:35:22.123'   SELECT @dt as SQLTime     , CAST(CAST((CAST(@dt as Float) - 25567.0) * 86400000.0 as DECIMAL(15,0)) as VARCHAR(15)) as JavaTime Interestingly, I found that converting to SQL Date time can lose some accuracy, when I converted the time above to Java time then converted  that back to DateTime, the number of milliseconds is 120, not 123.  As I am not interested in the milliseconds, this is ok for me.  But you may want to look into using DateTime2 in SQL Server 2008 for more accuracy.

    Read the article

  • Rename Applications and Virtual Directories in IIS7

    - by AngelEyes
    from http://lanitdev.wordpress.com/2010/09/02/rename-applications-and-virtual-directories-in-iis7/   Rename Applications and Virtual Directories in IIS7 September 2, 2010 — Brian Grinstead Have you ever wondered why the box to change the name or “Alias” on an application or virtual directory is greyed out (see screenshot below)? I found a way to change the name without recreating all your settings. It uses the built in administration commands in IIS7, called appcmd. Renaming Applications In IIS7 Open a command prompt to see all of your applications. 1 C:> %systemroot%\system32\inetsrv\appcmd list app 2   3     APP "Default Web Site/OldApplicationName" 4     APP "Default Web Site/AnotherApplication" Run a command like this to change your “OldApplicationName” path to “NewApplicationName”. Now you can use http://localhost/newapplicationname 1 C:> %systemroot%\system32\inetsrv\appcmd set app "Default Web Site/OldApplicationName" -path:/NewApplicationName 2   3     APP object "Default Web Site/OldApplicationName" changed Renaming Virtual Directories In IIS7 Open a command prompt to see all of your virtual directories. 1 C:> %systemroot%\system32\inetsrv\appcmd list appcmd 2   3     VDIR "Default Web Site/OldApplicationName/Images" (physicalPath:\\server\images) 4     VDIR "Default Web Site/OldApplicationName/Data/Config" (physicalPath:\\server\config) We want to rename /Images to /Images2 and /Data/Config to /Data/Config2. Here are the example commands: 1 C:> %systemroot%\system32\inetsrv\appcmd set vdir "Default Web Site/OldApplicationName/Images" -path:/Images2 2   3     VDIR object "Default Web Site/OldApplicationName/Images" changed 4   5 C:> %systemroot%\system32\inetsrv\appcmd set vdir "Default Web Site/OldApplicationName/Data/Config" -path:/Data/Config2 6   7     VDIR object "Default Web Site/OldApplicationName/Data/Config" changed

    Read the article

  • 9 New BizTalk Wencasts in the Light & Easy Series

    - by Alan Smith
    During the MVP summit in February I managed to catch up with a few of the BizTalk MVPs who had recorded new webcasts for the “BizTalk Light & Easy” series. The 9 new webcasts are online now at CloudCasts. ·         BizTalk 2010 and Windows Azure – Paul Somers ·         BizTalk and AppFabric Cache Part 1 – Mike Stephenson ·         BizTalk and AppFabric Cache Part 2 – Mike Stephenson ·         Integration to SharePoint 2010 Part 1 – Mick Badran ·         Integration to SharePoint 2010 Part 2 – Mick Badran ·         Better BizTalk Testing by Taking Advantage of the CAT Logging Framework – Mike Stephenson ·         Calling Business Rules from a .NET Application – Alan Smith ·         Tracking Rules Execution in a .NET Application – Alan Smith ·         Publishing a Business Rules Policy as a Service – Alan Smith The link is here. Big thanks to Paul, Mike and Mick for putting the time in. “BizTalk Light & Easy” is an ongoing project, if you are feeling creative and would like to contribute feel free to contact me via this blog. I can email you some tips on webcasting and the best formats to use.

    Read the article

  • F# and ArcObjects, Part 2

    - by Marko Apfel
    After accessing one feature now iterating through all features of a feature class: open System;; #I "C:\Program Files\ArcGIS\DotNet";; #r "ESRI.ArcGIS.System.dll";; #r "ESRI.ArcGIS.DataSourcesGDB.dll";; #r "ESRI.ArcGIS.Geodatabase.dll";; open ESRI.ArcGIS.esriSystem;; open ESRI.ArcGIS.DataSourcesGDB;; open ESRI.ArcGIS.Geodatabase;; let aoInitialize = new AoInitializeClass();; let status = aoInitialize.Initialize(esriLicenseProductCode.esriLicenseProductCodeArcEditor);; let workspacefactory = new SdeWorkspaceFactoryClass();; let connection = "SERVER=okul;DATABASE=p;VERSION=sde.default;INSTANCE=sde:sqlserver:okul;USER=s;PASSWORD=g";; let workspace = workspacefactory.OpenFromString(connection, 0);; let featureWorkspace = (box workspace) :?> IFeatureWorkspace;; let featureClass = featureWorkspace.OpenFeatureClass("Praxair.SFG.BP_L_ROHR");; let queryFilter = new QueryFilterClass();; let featureCursor = featureClass.Search(queryFilter, true);; let featureCursorSeq (featureCursor : IFeatureCursor) = let actualFeature = ref (featureCursor.NextFeature()) seq { while (!actualFeature) <> null do yield actualFeature do actualFeature := featureCursor.NextFeature() };; featureCursorSeq featureCursor |> Seq.iter (fun feature -> Console.WriteLine ((!feature).OID));;

    Read the article

  • Building a Distributed Commerce Infrastructure in the Cloud using Azure and Commerce Server

    - by Lewis Benge
    One of the biggest questions I routinely get asked is how scalable Commerce Server is. Of course the text book answer is the product has been around for 10 years, powers some of the largest e-Commerce websites in the world, so it scales horizontally extremely well. One argument however though is what if you can't predict the growth of demand required of your Commerce Platform, or need the ability to scale up during busy seasons such as Christmas for a retail environment but are hesitant on maintaining the infrastructure on a year-round basis? The obvious answer is to utilise the many elasticated cloud infrastructure providers that are establishing themselves in the ever-growing market, the problem however is Commerce Server is still product which has a legacy tightly coupled dependency on Windows and IIS components. Commerce Server 2009 codename "R2" however introduced to the concept of an n-tier deployment of Microsoft Commerce Server, meaning you are no longer tied to core objects API but instead have serializable Commerce Entity objects, and business logic allowing for Commerce Server to now be built into a WCF-based SOA architecture. Presentation layers no-longer now need to remain on the same physical machine as the application server, meaning you can now build the user experience into multiple-technologies and host them in multiple places – leveraging the transport benefits that a WCF service may bring, such as message queuing, security, and multiple end-points. All of this logic will still need to remain in your internal infrastructure, for two reasons. Firstly cloud based computing infrastructure does not support PCI security requirements, and secondly even though many of the legacy Commerce Server dependencies have been abstracted away within this version of the application, it is still not a fully supported to be deployed exclusively into the cloud. If you do wish to benefit from the scalability of the cloud however, you can still achieve a great Commerce Server and Azure setup by utilising both the Azure App Fabric in terms of the service bus, and authentication services and Windows Azure to host any online presence you may require. The architecture would be something similar to this: This setup would allow you to construct your Commerce Services as part of your on-site infrastructure. These services would contain all of the channels custom business logic, and provide the overall interface back into the underlying Commerce Server components. It would be recommended that services are constructed around the specific business domain of the application, which based on your business model would usually consist of separate services around Catalogue, Orders, Search, Profiles, and Marketing. The App Fabric service bus is then used to abstract and aggregate further the services, making them available to the cloud and subsequently secured by App Fabrics authentication services. These services are now available for consumption by any client, using any supported technology – not just .NET. Thus meaning you are now able to construct apps for IPhone, integrate with Java based POS Devices, and any many other potential uses. This aggregation is useful, and forms the basis of the further strategy around diversifying and enhancing the e-Commerce experience, but also provides the foundation for the scalability we want to gain from utilising a cloud-based application platform. The Windows Azure application platform is Microsoft solution to benefiting from the true economies of scale in terms of the elasticity of the cloud. Just before the launch of the Azure Platform – Domino's pizza actually managed to run their whole SuperBowl operation from the scalability of Windows Azure, and simply switching back to their traditional operation the next day with no residual infrastructure costs. The platform also natively can subscribe to services and messages exposed within the AppFabric service bus, making it an ideal solution to build and deploy a presentation layer which will need to support of scalable infrastructure – such as a high demand public facing e-Commerce portal, or a promotion element of a brand. Windows Azure has excellent support for ASP.NET, including its own caching providers meaning expensive operations such as catalogue queries can persist in memory on the application server, reducing the demand on internal infrastructure and prioritising it for more business critical operations such as receiving orders and processing payments. Windows Azure also supports other languages too, meaning utilising this approach you can technically build a Commerce Server presentation layer in Java, PHP, or Ruby – or equally in ASP.NET or Silverlight without having to change any of the underlying business or Commerce Server implementation. This SOA-style architecture is one of the primary differentiators for Commerce Server as a product in the e-Commerce market, and now with the introduction of a WCF capability in Commerce Server 2009/2009 R2 the opportunities for extensibility of the both the user experience, and integration into third parties, are drastically increased, all with no effect to the underlying channel logic. So if you are looking at deployment options for your e-Commerce application to help support demand in a cost effective way. I would highly recommend you consider looking at Windows Azure, and if you have any questions in-particular about this style of deployment, please feel free to get in touch!

    Read the article

  • Windows CE training in Italy

    - by Valter Minute
    Se volete approfondire le vostre conoscenze su Windows CE (anche relativamente alle novità introdotte con la versione R3), o desiderate acquisire le basi per cominciare a lavorare con questo sistema operativo, questa è un'occasione da non perdere. Dal 12 al 16 Aprile si terrà presso gli uffici di Fortech Embedded Labs di Saronno (VA) il corso "Building Solutions with Windows Embedded CE 6.0", tenuto dal sottoscritto. Per maggiori informazioni sui contenuti e i costi: http://www.fortechembeddedlabs.it/node/27

    Read the article

  • It&rsquo;s ok to throw System.Exception&hellip;

    - by Chris Skardon
    No. No it’s not. It’s not just me saying that, it’s the Microsoft guidelines: http://msdn.microsoft.com/en-us/library/ms229007.aspx  Do not throw System.Exception or System.SystemException. Also – as important: Do not catch System.Exception or System.SystemException in framework code, unless you intend to re-throw.. Throwing: Always, always try to pick the most specific exception type you can, if the parameter you have received in your method is null, throw an ArgumentNullException, value received greater than expected? ArgumentOutOfRangeException. For example: public void ArgChecker(int theInt, string theString) { if (theInt < 0) throw new ArgumentOutOfRangeException("theInt", theInt, "theInt needs to be greater than zero."); if (theString == null) throw new ArgumentNullException("theString"); if (theString.Length == 0) throw new ArgumentException("theString needs to have content.", "theString"); } Why do we want to do this? It’s a lot of extra code when compared with a simple: public void ArgChecker(int theInt, string theString) { if (theInt < 0 || string.IsNullOrWhiteSpace(theString)) throw new Exception("The parameters were invalid."); } It all comes down to a couple of things; the catching of the exceptions, and the information you are passing back to the calling code. Catching: Ok, so let’s go with introduction level Exception handling, taught by many-a-university: You do all your work in a try clause, and catch anything wrong in the catch clause. So this tends to give us code like this: try { /* All the shizzle */ } catch { /* Deal with errors */ } But of course, we can improve on that by catching the exception so we can report on it: try { } catch(Exception ex) { /* Log that 'ex' occurred? */ } Now we’re at the point where people tend to go: Brilliant, I’ve got exception handling nailed, what next??? and code gets littered with the catch(Exception ex) nastiness. Why is it nasty? Let’s imagine for a moment our code is throwing an ArgumentNullException which we’re catching in the catch block and logging. Ok, the log entry has been made, so we can debug the code right? We’ve got all the info… What about an OutOfMemoryException – what can we do with that? That’s right, not a lot, chances are you can’t even log it (you are out of memory after all), but you’ve caught it – and as such - have hidden it. So, as part of this, there are two things you can do one, is the rethrow method: try { /* code */ } catch (Exception ex) { //Log throw; } Note, it’s not catch (Exception ex) { throw ex; } as that will wipe all your important stack trace information. This does get your exception to continue, and is the only reason you would catch Exception (anywhere other than a global catch-all) in your code. The other preferred method is to catch the exceptions you can deal with. It may not matter that the string I’m passing in is null, and I can cope with it like this: try{ DoSomething(myString); } catch(ArgumentNullException){} And that’s fine, it means that any exceptions I can’t deal with (OutOfMemory for example) will be propagated out to other code that can deal with it. Of course, this is horribly messy, no one wants try / catch blocks everywhere and that’s why Microsoft added the ‘Try’ methods to the framework, and it’s a strategy we should continue. If I try: int i = (int) "one"; I will get an InvalidCastException which means I need the try / catch block, but I could mitigate this using the ‘TryParse’ method: int i; if(!Int32.TryParse("one", out i)) return; Similarly, in the ‘DoSomething’ example, it might be beneficial to have a ‘TryDoSomething’ that returns a boolean value indicating the success of continuing. Obviously this isn’t practical in every case, so use the ol’ common sense approach. Onwards Yer thanks Chris, I’m looking forward to writing tonnes of new code. Fear not, that is where helpers come into it… (but that’s the next post)

    Read the article

  • CQRS &ndash; Questions and Concerns

    - by Dylan Smith
    I’ve been doing a lot of learning on CQRS and Event Sourcing over the last little while and I have a number of questions that I haven’t been able to answer. 1. What is the benefit of CQRS when compared to a typical DDD architecture that uses Event Sourcing and properly captures intent and behavior via verb-based commands? (other than Scalability) 2. When using CQRS what do you do with complex query-based logic? I’m going to elaborate on #1 in this blog post and I’ll do a follow-up post on #2. I watched through Greg Young’s video on the business benefits of CQRS + Event Sourcing and first let me say that I thought it was an excellent presentation that really drives home a lot of the benefits to this approach to architecture (I watched it twice in a row I enjoyed it so much!). But it didn’t answer some of my questions fully (I wish I had been there to ask these of Greg in person!). So let me pick apart some of the points he makes and how they relate to my first question above. I’m completely sold on the idea of event sourcing and have a clear understanding of the benefits that it brings to the table, so I’m not going to question that. But you can use event sourcing without going to a CQRS architecture, so my main question is around the benefits of CQRS + Event Sourcing vs Event Sourcing + Typical DDD architecture Architecture with Event Sourcing + Commands on Left, CQRS on Right Greg talks about how the stereotypical architecture doesn’t support DDD, but is that only because his diagram shows DTO’s coming up from the client. If we use the same diagram but allow the client to send commands doesn’t that remove a lot of the arguments that Greg makes against the stereotypical architecture? We can now introduce verbs into the system. We can capture intent now (storing it still requires event sourcing, but you can implement event sourcing without doing CQRS) We can create a rich domain model (as opposed to an anemic domain model) Scalability is obviously a benefit that CQRS brings to the table, but like Greg says, very few of the systems we create truly need significant scalability Greg talks about the ability to scale your development efforts. He says CQRS allows you to split the system into 3 parts (Client, Domain/Commands, Reads) and assign 3 teams of developers to work on them in parallel; letting you scale your development efforts by 3x with nearly linear gains. But in the stereotypical architecture don’t you already have 2 separate modules that you can split your dev efforts between: The client that sends commands/queries and receives DTO’s, and the Domain which accepts commands/queries, and generates events/DTO’s. If this is true it’s not really a 3x scaling you achieve with CQRS but merely a 1.5x scaling which while great doesn’t sound nearly as dramatic (“I can do it with 10 devs in 12 months – let me hire 5 more and we can have it done in 8 months”). Making the Query side “stupid simple” such that you can assign junior developers (or even outsource it) sounds like a valid benefit, but I have some concerns over what you do with complex query-based logic/behavior. I’m going to go into more detail on this in a follow-up blog post shortly. He also seemed to focus on how “stupid-simple” it is doing queries against the de-normalized data store, but I imagine there is still significant complexity in the event handlers that interpret the events and apply them to the de-normalized tables. It sounds like Greg suggests that because we’re doing CQRS that allows us to apply Event Sourcing when we otherwise wouldn’t be able to (~33:30 in the video). I don’t believe this is true. I don’t see why you wouldn’t be able to apply Event Sourcing without separating out the Commands and Queries. The queries would just operate against the domain model instead of the database. But you’d still get the benefits of Event Sourcing. Without CQRS the queries would only be able to operate against the current state rather than the event history, but even in CQRS the domain behaviors can only operate against the current state and I don’t see that being a big limiting factor. If some query needs to operate against something that is not captured by the current state you would just have to update the domain model to capture that information (no different than if that statement were made about a Command under CQRS). Some of the benefits I do see being applicable are that your domain model might end up being simpler/smaller since it only needs to represent the state needed to process commands and not worry about the reads (like the Deactivate Inventory Item and associated comment example that Greg provides). And also commands that can be handled in a Transaction Script style manner by the command handler simply generating events and not touching the domain model. It also makes it easier for your senior developers to focus on the command behavior and ignore the queries, which is usually going to be a better use of their time. And of course scalability. If anybody out there has any thoughts on this and can help educate me further, please either leave a comment or feel free to get in touch with me via email:

    Read the article

  • Sorting Algorithms

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

    Read the article

  • Microsoft UX Kit

    - by Josh Holmes
    Have you ever wondered what was possible with Silverlight, WPF or any of Microsoft’s User Experience (UX) technologies? Well, Christian Thilmany has answered that question in the form of the Microsoft UX Kit. Read more at Microsoft UX Kit | Josh Holmes

    Read the article

  • .NET Rocks is on the Road Again!

    - by Scott Spradlin
    Carl and Richard are loading up the DotNetMobile (a 30 foot RV) and driving to our town again to show off their favorite bits of Visual Studio 2010 and .NET 4.0! Richard talks about Web load testing and Carl talks about Silverlight 4.0 and multimedia. And to make the night even more fun, they are going to bring a mystery rock star from the Visual Studio world to the event and interview them for a special .NET Rocks Road Trip show series. Along the way we’ll be giving away some great prizes, showing off some awesome technology and having a ton of laughs. So come out to the most fun you can have in a geeky evening - and learn a few things along the way about web load testing and Silverlight 4! And one lucky person at the event will win "Ride Along with Carl and Richard" and get to board the RV and ride with the boys to the next town on the tour -- Chicago. (don’t worry, they will get you home again!) So come out to the most fun you can have in a geeky evening – and find out what’s new and cool in Visual Studio 2010! To get insure we have sufficient food for everyone, please register for this event at http://stlnet.eventbrite.com This registration information will only be used to obtain accurate counts for food preparation. All other answers are optional and will be used for purely statistical analysis. No information will be shared outside the St. Louis .NET User Group. Here is a list of prizes to be given away at the event: Telerik Premium Collection Pre-Emptive One Year Commercial Runtime Intelligence license Red Gate ANTS Memory Profiler Quest Toad Extension for Visual Studio DevExpress Code Rush and Refactor Pro Grape City Active Report/BI Suite Grape City Spread 5.0 JetBrains Resharper Component One Studio for ASP.NET Component One Studio for Silverlight Please check out the event sponsors: Visit http://www.dotnetrocks.com/roadtrip for more information! Thursday, April 29, 2010 6:00 pm - Food and social 6:30 pm - .NET Rocks Interview 7:15 pm - Richard Campbell 8:00 pm - Carl Franklin 8:45 pm - prizes!

    Read the article

  • Michael Stephenson joins CloudCasts

    - by Alan Smith
    Mike Stephenson has recorded a couple of webcasts focusing on build and test in BizTalk Server 2009. These are part of the “BizTalk Light & Easy” series of webcasts created by some of the BizTalk Server MVPs. Testing BizTalk Applications Implementing an Automated Build Process with BizTalk Server 2009

    Read the article

  • Using NServiceBus behind a custom web service

    - by Michael Stephenson
    In this post I'd like to talk about an architecture scenario we had recently and how we were able to utilise NServiceBus to help us address this problem. Scenario Cognos is a reporting system used by one of my clients. A while back we developed a web service façade to allow line of business applications to be able to access reports from Cognos to support their various functions. The service was intended to provide access to reports which were quick running reports or pre-generated reports which could be accessed real-time on demand. One of the key aims of the web service was to provide a simple generic interface to allow applications to get any report without needing to worry about the complex .net SDK for Cognos. The web service also supported multi-hop kerberos delegation so that report data could be accesses under the context of the end user. This service was working well for a period of time. The Problem The problem we encountered was that reports were now also required to be available to batch processes. The original design was optimised for low latency so users would enjoy a positive experience, however when the batch processes started to request 250+ concurrent reports over an extended period of time you can begin to imagine the sorts of problems that come into play. The key problems this new scenario caused are: Users may be affected and the latency of on demand reports was significantly slower The Cognos infrastructure was not scaled sufficiently to be able to cope with these long peaks of load From a cost perspective it just isn't feasible to scale the Cognos infrastructure to be able to handle the load when it is only for a couple of hour window each night. We really needed to introduce a second pattern for accessing this service which would support high through-put scenarios. We also had little control over the batch process in terms of being able to throttle its load. We could however make some changes to the way it accessed the reports. The Approach My idea was to introduce a throttling mechanism between the Web Service Façade and Cognos. This would allow the batch processes to push reports requests hard at the web service which we were confident the web service can handle. The web service would then queue these requests and process them behind the scenes and make a call back to the batch application to provide the report once it had been accessed. In terms of technology we had some limitations because we were not able to use WCF or IIS7 where the MSMQ-Activated WCF services could have helped, but we did have MSMQ as an option and I thought NServiceBus could do just the job to help us here. The flow of how this would work was as follows: The batch applications would send a request for a report to the web service The web service uses NServiceBus to send the message to a Queue The NServiceBus Generic Host is running as a windows service with a message handler which subscribes to these messages The message handler gets the message, accesses the report from Cognos The message handler calls back to the original batch application, this is decoupled because the calling application provides a call back url The report gets into the batch application and is processed as normal This approach looks something like the below diagram: The key points are an application wanting to take advantage of the batch driven reports needs to do the following: Implement our call back contract Make a call to the service providing a call back url Provide a correlation ID so it knows how to tie each response back to its request What does NServiceBus offer in this solution So this scenario is not the typical messaging service bus type of solution people implement with NServiceBus, but it did offer the following: Simplified interaction with MSMQ Offered the ability to configure the number of processes working through the queue so we could find a balance between load on Cognos versus the applications end to end processing time NServiceBus offers retries and a way to manage failed messages NServiceBus offers a high availability setup The simple thing is that NServiceBus gave us the platform to build the solution on. We just implemented a message handler which functionally processed a message and we could rely on NServiceBus to do all of the hard work around managing the queues and all of the lower level things that would have took ages to write to any kind of robust level. Conclusion With this approach we were able to deal with a fairly significant performance issue with out too much rework. Hopefully this write up gives people some insight into ideas on how to leverage the excellent NServiceBus framework to help solve integration and high through-put scenarios.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 26 27 28 29 30 31 32 33 34 35 36 37  | Next Page >