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  • WPF: Why all the love for the Grid control?

    - by Eduardo Molteni
    Seen various examples of WPF applications I've seen the use of the Grid control for almost anything, even simplest things with only 1 column or row. Also, the WPF templates start with an empty grid. For me, using StackPanel or DockPanel is less verbose and are better for maintenance (think adding a row later and having to add +1 to all the other rows) Why is Grid better or what I am missing?

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  • What is the lightest way to make a huge chess-like grid?

    - by Sotkra
    Hey there I'm working on a browser-game and I can't help but wonder about what's the lightest way to make the grid/board on which the game takes place. Right now, as a mere sample, I'll show you this: http://sotkra.com/game/ Now, as the grid gets bigger and bigger, the table and its td's create a very heavy filepage which in turn...sucks in more resources from the browser engine and computer. So, is a table with td's the most lightweight way to craft a huge grid-like board or is there something lighter that you recommend? Cheers Sotkra

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  • Drag and drop between ListBox items and Grid cells in WPF?

    - by AJ
    Hi There is a list box with some items in it. Also there is a grid with 3x3 matrix. The user will be dragging an item and dropping on one the cells of grid. Most of the samples I found are about dragging-dropping from one listbox to another listbox. But I want to drop in one cell of grid. How can I achieve this? Please advise. thanks PJ

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  • Telerik ASP.NET MVC2 Grid Delete Function with compound key.

    - by Dani
    I have a grid with a compound key: OrderId, ItemID. When I update the grid - the public ActionResult UpdateItemGridAjax(int OrderID, string ItemID) Gets both values from the grid. When I delete a row I get only the first one: public ActionResult DeleteItemGridAjax(int OrderID, string ItemID) Why is it happens and how can I get the ItemId value of the deleted row ? Grid Definition: <%= Html.Telerik().Grid<ItemsInOrderPOCO>() .Name("ItemsInOrderGrid") .DataKeys(dataKeys => { dataKeys.Add(e => e.OrderID); dataKeys.Add(e => e.ItemID); }) .ToolBar(commands => commands.Insert()) .DataBinding(dataBinding => { dataBinding.Ajax() //Ajax binding .Select("SelectItemGridAjax", "Orders", new { OrderID = Model.myOrder.OrderID }) .Insert("InsertItemGridAjax", "Orders", new { OrderID = Model.myOrder.OrderID }) .Update("UpdateItemGridAjax", "Orders") .Delete("DeleteItemGridAjax", "Orders"); }) .Columns(c => { c.Bound(o => o.ItemID); c.Bound(o => o.OrderID).Column.Visible = false; c.Bound(o => o.ItemDescription); c.Bound(o => o.NumOfItems); c.Bound(o => o.CostOfItem); c.Bound(o => o.TotalCost); c.Bound(o => o.SupplyDate); c.Command(commands => { commands.Edit(); commands.Delete(); }).Width(180).Title("Upadte"); })

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  • Azure Grid Computing - Worker Roles as HPC Compute Nodes

    - by JoshReuben
    Overview ·        With HPC 2008 R2 SP1 You can add Azure worker roles as compute nodes in a local Windows HPC Server cluster. ·        The subscription for Windows Azure like any other Azure Service - charged for the time that the role instances are available, as well as for the compute and storage services that are used on the nodes. ·        Win-Win ? - Azure charges the computer hour cost (according to vm size) amortized over a month – so you save on purchasing compute node hardware. Microsoft wins because you need to purchase HPC to have a local head node for managing this compute cluster grid distributed in the cloud. ·        Blob storage is used to hold input & output files of each job. I can see how Parametric Sweep HPC jobs can be supported (where the same job is run multiple times on each node against different input units), but not MPI.NET (where different HPC Job instances function as coordinated agents and conduct master-slave inter-process communication), unless Azure is somehow tunneling MPI communication through inter-WorkerRole Azure Queues. ·        this is not the end of the story for Azure Grid Computing. If MS requires you to purchase a local HPC license (and administrate it), what's to stop a 3rd party from doing this and encapsulating exposing HPC WCF Broker Service to you for managing compute nodes? If MS doesn’t  provide head node as a service, someone else will! Process ·        requires creation of a worker node template that specifies a connection to an existing subscription for Windows Azure + an availability policy for the worker nodes. ·        After worker nodes are added to the cluster, you can start them, which provisions the Windows Azure role instances, and then bring them online to run HPC cluster jobs. ·        A Windows Azure worker role instance runs a HPC compatible Azure guest operating system which runs on the VMs that host your service. The guest operating system is updated monthly. You can choose to upgrade the guest OS for your service automatically each time an update is released - All role instances defined by your service will run on the guest operating system version that you specify. see Windows Azure Guest OS Releases and SDK Compatibility Matrix (http://go.microsoft.com/fwlink/?LinkId=190549). ·        use the hpcpack command to upload file packages and install files to run on the worker nodes. see hpcpack (http://go.microsoft.com/fwlink/?LinkID=205514). Requirements ·        assuming you have an azure subscription account and the HPC head node installed and configured. ·        Install HPC Pack 2008 R2 SP 1 -  see Microsoft HPC Pack 2008 R2 Service Pack 1 Release Notes (http://go.microsoft.com/fwlink/?LinkID=202812). ·        Configure the head node to connect to the Internet - connectivity is provided by the connection of the head node to the enterprise network. You may need to configure a proxy client on the head node. Any cluster network topology (1-5) is supported). ·        Configure the firewall - allow outbound TCP traffic on the following ports: 80,       443, 5901, 5902, 7998, 7999 ·        Note: HPC Server  uses Admin Mode (Elevated Privileges) in Windows Azure to give the service administrator of the subscription the necessary privileges to initialize HPC cluster services on the worker nodes. ·        Obtain a Windows Azure subscription certificate - the Windows Azure subscription must be configured with a public subscription (API) certificate -a valid X.509 certificate with a key size of at least 2048 bits. Generate a self-sign certificate & upload a .cer file to the Windows Azure Portal Account page > Manage my API Certificates link. see Using the Windows Azure Service Management API (http://go.microsoft.com/fwlink/?LinkId=205526). ·        import the certificate with an associated private key on the HPC cluster head node - into the trusted root store of the local computer account. Obtain Windows Azure Connection Information for HPC Server ·        required for each worker node template ·        copy from azure portal - Get from: navigation pane > Hosted Services > Storage Accounts & CDN ·        Subscription ID - a 32-char hex string in the form xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. In Properties pane. ·        Subscription certificate thumbprint - a 40-char hex string (you need to remove spaces). In Management Certificates > Properties pane. ·        Service name - the value of <ServiceName> configured in the public URL of the service (http://<ServiceName>.cloudapp.net). In Hosted Services > Properties pane. ·        Blob Storage account name - the value of <StorageAccountName> configured in the public URL of the account (http://<StorageAccountName>.blob.core.windows.net). In Storage Accounts > Properties pane. Import the Azure Subscription Certificate on the HPC Head Node ·        enable the services for Windows HPC Server  to authenticate properly with the Windows Azure subscription. ·        use the Certificates MMC snap-in to import the certificate to the Trusted Root Certification Authorities store of the local computer account. The certificate must be in PFX format (.pfx or .p12 file) with a private key that is protected by a password. ·        see Certificates (http://go.microsoft.com/fwlink/?LinkId=163918). ·        To open the certificates snapin: Run > mmc. File > Add/Remove Snap-in > certificates > Computer account > Local Computer ·        To import the certificate via wizard - Certificates > Trusted Root Certification Authorities > Certificates > All Tasks > Import ·        After the certificate is imported, it appears in the details pane in the Certificates snap-in. You can open the certificate to check its status. Configure a Proxy Client on the HPC Head Node ·        the following Windows HPC Server services must be able to communicate over the Internet (through the firewall) with the services for Windows Azure: HPCManagement, HPCScheduler, HPCBrokerWorker. ·        Create a Windows Azure Worker Node Template ·        Edit HPC node templates in HPC Node Template Editor. ·        Specify: 1) Windows Azure subscription connection info (unique service name) for adding a set of worker nodes to the cluster + 2)worker node availability policy – rules for deploying / removing worker role instances in Windows Azure o   HPC Cluster Manager > Configuration > Navigation Pane > Node Templates > Actions pane > New à Create Node Template Wizard or Edit à Node Template Editor o   Choose Node Template Type page - Windows Azure worker node template o   Specify Template Name page – template name & description o   Provide Connection Information page – Azure Subscription ID (text) & Subscription certificate (browse) o   Provide Service Information page - Azure service name + blob storage account name (optionally click Retrieve Connection Information to get list of available from azure – possible LRT). o   Configure Azure Availability Policy page - how Windows Azure worker nodes start / stop (online / offline the worker role instance -  add / remove) – manual / automatic o   for automatic - In the Configure Windows Azure Worker Availability Policy dialog -select days and hours for worker nodes to start / stop. ·        To validate the Windows Azure connection information, on the template's Connection Information tab > Validate connection information. ·        You can upload a file package to the storage account that is specified in the template - eg upload application or service files that will run on the worker nodes. see hpcpack (http://go.microsoft.com/fwlink/?LinkID=205514). Add Azure Worker Nodes to the HPC Cluster ·        Use the Add Node Wizard – specify: 1) the worker node template, 2) The number of worker nodes   (within the quota of role instances in the azure subscription), and 3)           The VM size of the worker nodes : ExtraSmall, Small, Medium, Large, or ExtraLarge.  ·        to add worker nodes of different sizes, must run the Add Node Wizard separately for each size. ·        All worker nodes that are added to the cluster by using a specific worker node template define a set of worker nodes that will be deployed and managed together in Windows Azure when you start the nodes. This includes worker nodes that you add later by using the worker node template and, if you choose, worker nodes of different sizes. You cannot start, stop, or delete individual worker nodes. ·        To add Windows Azure worker nodes o   In HPC Cluster Manager: Node Management > Actions pane > Add Node à Add Node Wizard o   Select Deployment Method page - Add Azure Worker nodes o   Specify New Nodes page - select a worker node template, specify the number and size of the worker nodes ·        After you add worker nodes to the cluster, they are in the Not-Deployed state, and they have a health state of Unapproved. Before you can use the worker nodes to run jobs, you must start them and then bring them online. ·        Worker nodes are numbered consecutively in a naming series that begins with the root name AzureCN – this is non-configurable. Deploying Windows Azure Worker Nodes ·        To deploy the role instances in Windows Azure - start the worker nodes added to the HPC cluster and bring the nodes online so that they are available to run cluster jobs. This can be configured in the HPC Azure Worker Node Template – Azure Availability Policy -  to be automatic or manual. ·        The Start, Stop, and Delete actions take place on the set of worker nodes that are configured by a specific worker node template. You cannot perform one of these actions on a single worker node in a set. You also cannot perform a single action on two sets of worker nodes (specified by two different worker node templates). ·        ·          Starting a set of worker nodes deploys a set of worker role instances in Windows Azure, which can take some time to complete, depending on the number of worker nodes and the performance of Windows Azure. ·        To start worker nodes manually and bring them online o   In HPC Node Management > Navigation Pane > Nodes > List / Heat Map view - select one or more worker nodes. o   Actions pane > Start – in the Start Azure Worker Nodes dialog, select a node template. o   the state of the worker nodes changes from Not Deployed to track the provisioning progress – worker node Details Pane > Provisioning Log tab. o   If there were errors during the provisioning of one or more worker nodes, the state of those nodes is set to Unknown and the node health is set to Unapproved. To determine the reason for the failure, review the provisioning logs for the nodes. o   After a worker node starts successfully, the node state changes to Offline. To bring the nodes online, select the nodes that are in the Offline state > Bring Online. ·        Troubleshooting o   check node template. o   use telnet to test connectivity: telnet <ServiceName>.cloudapp.net 7999 o   check node status - Deployment status information appears in the service account information in the Windows Azure Portal - HPC queries this -  see  node status information for any failed nodes in HPC Node Management. ·        When role instances are deployed, file packages that were previously uploaded to the storage account using the hpcpack command are automatically installed. You can also upload file packages to storage after the worker nodes are started, and then manually install them on the worker nodes. see hpcpack (http://go.microsoft.com/fwlink/?LinkID=205514). ·        to remove a set of role instances in Windows Azure - stop the nodes by using HPC Cluster Manager (apply the Stop action). This deletes the role instances from the service and changes the state of the worker nodes in the HPC cluster to Not Deployed. ·        Each time that you start a set of worker nodes, two proxy role instances (size Small) are configured in Windows Azure to facilitate communication between HPC Cluster Manager and the worker nodes. The proxy role instances are not listed in HPC Cluster Manager after the worker nodes are added. However, the instances appear in the Windows Azure Portal. The proxy role instances incur charges in Windows Azure along with the worker node instances, and they count toward the quota of role instances in the subscription.

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  • Are we ready for the Cloud computing era?

    - by andrewkatumba
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} "Elite?" developer circles are abuzz with the notion of Cloud computing . The increasing bandwidth, the desire for faster and leaner operations and ofcourse the need for outsourcing non core it related business requirements e.g wordprocessing, spreadsheets, data backups. In strolls Chrome OS (am sure other similar OSes will join with their own wagons for us to jump on), offering just that, internet based services(more like a repository of), quick efficient and "reliable" and for the most part cheap and often time even free! And we all go rhapsodic!  It boils down to the age old dilemma, "if the cops are so busy protecting us then who will protect them" (even the folks back at Hollywood keep us reminded)! Who is going to ensure that these internet based services do not go down(either intentionally or by some malicious third party) leading to a multinational colossal disaster .At the risk of sounding pessimistic,  IT IS NOT AN ISSUE OF TRUST, this is but a mere case of Murphy's Law!  What then? Should the "cloud" be trusted to this extent at this time?  This is an era where challenges are rapidly solved with lightning promptness to "beat the competition", my hope is that our solutions are not just creating problems that we may not be able to solve!  Keeping my ear on the Ground.

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  • Silverlight ValidationSummary screen real estate

    - by Mark Cooper
    Silverlight 3; I have a ValidationSummary in the top row of my grid. When the ValidationSummary appears, it pushes my button row (row 3) off the bottom of the displayable screen. <Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch"> <Grid.RowDefinitions> <RowDefinition Height="Auto" /> <RowDefinition Height="Auto" /> <RowDefinition Height="36" /> </Grid.RowDefinitions> <di:ValidationSummary Grid.Row="0" /> <Grid x:Name="gridOuterContentHolder" Grid.Row="1"> <Grid.RowDefinitions> <RowDefinition Height="0.68*" /> <RowDefinition Height="5" /> <RowDefinition Height="0.32*" /> </Grid.RowDefinitions> <!-- elements removed for brevity --> </Grid> <StackPanel x:Name="stack" Grid.Row="2" Orientation="Horizontal" HorizontalAlignment="Right"> <Button Content="Delete" x:Name="btnDelete" Height="20" Width="75" /> </StackPanel> </Grid> I'm a code monkey not a pixel pusher and can't figure out which combination of Stretch's, Auto's and *'s I need. Any pushers out there that can help?? Thanks, Mark

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  • Windows Azure Learning Plan - Security

    - by BuckWoody
    This is one in a series of posts on a Windows Azure Learning Plan. You can find the main post here. This one deals with Security for  Windows Azure.   General Security Information Overview and general  information about Windows Azure Security - what it is, how it works, and where you can learn more. General Security Whitepaper – answers most questions http://blogs.msdn.com/b/usisvde/archive/2010/08/10/security-white-paper-on-windows-azure-answers-many-faq.aspx Windows Azure Security Notes from the Patterns and Practices site http://blogs.msdn.com/b/jmeier/archive/2010/08/03/now-available-azure-security-notes-pdf.aspx Overview of Azure Security http://www.windowsecurity.com/articles/Microsoft-Azure-Security-Cloud.html Azure Security Resources http://reddevnews.com/articles/2010/08/19/microsoft-releases-windows-azure-security-resources.aspx Cloud Computing Security Considerations http://www.microsoft.com/downloads/en/details.aspx?FamilyID=68fedf9c-1c27-4642-aa5b-0a34472303ea&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+MicrosoftDownloadCenter+%28Microsoft+Download+Center Security in Cloud Computing – a Microsoft Perspective http://www.microsoft.com/downloads/en/details.aspx?FamilyID=7c8507e8-50ca-4693-aa5a-34b7c24f4579&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+MicrosoftDownloadCenter+%28Microsoft+Download+Center Physical Security for Microsoft’s Online Computing Information on the Infrastructure and Locations for Azure Physical Security. The Global Foundation Services Group at Microsoft handles physical security http://www.globalfoundationservices.com/security/index.html Microsoft’s Security Response Center http://www.microsoft.com/security/msrc/ Software Security for Microsoft’s Online Computing Steps we take as a company to develop secure software Windows Azure is developed using the Trustworthy Computing Initiative http://www.microsoft.com/about/twc/en/us/default.aspx and  http://msdn.microsoft.com/en-us/library/ms995349.aspx Identity and Access in the Cloud http://blogs.msdn.com/b/technology_titbits_by_rajesh_makhija/archive/2010/10/29/identity-and-access-in-the-cloud.aspx Security Steps you should take While Microsoft takes great pains to secure the infrastructure, platform and code for Windows Azure, you have a responsibility to write secure code. These pointers can help you do that. Securing your cloud architecture, step-by-step http://technet.microsoft.com/en-us/magazine/gg296364.aspx Security Guidelines for Windows Azure http://redmondmag.com/articles/2010/06/15/microsoft-issues-security-guidelines-for-windows-azure.aspx  Best Practices for Windows Azure Security http://blogs.msdn.com/b/vbertocci/archive/2010/06/14/security-best-practices-for-developing-windows-azure-applications.aspx Active Directory and Windows Azure http://blogs.msdn.com/b/plankytronixx/archive/2010/10/22/projecting-your-active-directory-identity-to-the-azure-cloud.aspx Understanding Encryption (great overview and tutorial) http://blogs.msdn.com/b/plankytronixx/archive/2010/10/23/crypto-primer-understanding-encryption-public-private-key-signatures-and-certificates.aspx Securing your Connection Strings (SQL Azure) http://blogs.msdn.com/b/sqlazure/archive/2010/09/07/10058942.aspx Getting started with Windows Identity Foundation (WIF) quickly http://blogs.msdn.com/b/alikl/archive/2010/10/26/windows-identity-foundation-wif-fast-track.aspx

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  • Computing a normal matrix in conjunction with gluLookAt

    - by Chris Smith
    I have a hand-rolled camera class that converts yaw, pitch, and roll angles into a forward, side, and up vector suitable for calling gluLookAt. Using this camera class I can modify the model-view matrix to move about the 3D world just fine. However, I am having trouble when using this camera class (and associated model-view matrix) when trying to perform directional lighting in my vertex shader. The problem is that the light direction, (0, 1, 0) for example, is relative to where the 'camera is looking' and not the actual world coordinates. (Or is this eye coordinates vs. model coordinates?) I would like the light direction to be unaffected by the camera's viewing direction. For example, when the camera is looking down the Z axis the ground is lit correctly. However, if I point the camera straight at the ground, then it goes dark. This is (I think) because the light direction is parallel with the camera's 'up' vector which is perpendicular with the ground's normal vector. I tried computing the normal matrix without taking the camera's model view into account, but then none of my objects were rotated correctly. Sorry if this sounds vague. I suspect there is a straight forward answer, but I'm not 100% clear on how the normal matrix should be used for transforming vertex normals in my vertex shader. For reference, here is pseudo code for my rendering loop: pMatrix = new Matrix(); pMatrix = makePerspective(...) mvMatrix = new Matrix() camera.apply(mvMatrix); // Calls gluLookAt // Move the object into position. mvMatrix.translatev(position); mvMatrix.rotatef(rotation.x, 1, 0, 0); mvMatrix.rotatef(rotation.y, 0, 1, 0); mvMatrix.rotatef(rotation.z, 0, 0, 1); var nMatrix = new Matrix(); nMatrix.set(mvMatrix.get().getInverse().getTranspose()); // Set vertex shader uniforms. gl.uniformMatrix4fv(shaderProgram.pMatrixUniform, false, new Float32Array(pMatrix.getFlattened())); gl.uniformMatrix4fv(shaderProgram.mvMatrixUniform, false, new Float32Array(mvMatrix.getFlattened())); gl.uniformMatrix4fv(shaderProgram.nMatrixUniform, false, new Float32Array(nMatrix.getFlattened())); // ... gl.drawElements(gl.TRIANGLES, this.vertexIndexBuffer.numItems, gl.UNSIGNED_SHORT, 0); And the corresponding vertex shader: // Attributes attribute vec3 aVertexPosition; attribute vec4 aVertexColor; attribute vec3 aVertexNormal; // Uniforms uniform mat4 uMVMatrix; uniform mat4 uNMatrix; uniform mat4 uPMatrix; // Varyings varying vec4 vColor; // Constants const vec3 LIGHT_DIRECTION = vec3(0, 1, 0); // Opposite direction of photons. const vec4 AMBIENT_COLOR = vec4 (0.2, 0.2, 0.2, 1.0); float ComputeLighting() { vec4 transformedNormal = vec4(aVertexNormal.xyz, 1.0); transformedNormal = uNMatrix * transformedNormal; float base = dot(normalize(transformedNormal.xyz), normalize(LIGHT_DIRECTION)); return max(base, 0.0); } void main(void) { gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0); float lightWeight = ComputeLighting(); vColor = vec4(aVertexColor.xyz * lightWeight, 1.0) + AMBIENT_COLOR; } Note that I am using WebGL, so if the anser is use glFixThisProblem(...) any pointers on how to re-implement that on WebGL if missing would be appreciated.

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  • Searching for cluster computation framework

    - by petkov_d
    I have a library, written in C#, containing one method: Response CalculateSomething(Request); The execution time of this method is relatively large, and there are a lot of responses that should be processed. I want to use a "cluster", spread this DLL to different machines (nodes) in this "cluster" and write some controller that will distribute responses to the nodes. There should be mechanism that perevent losing task because of node crush, load balancing. Can someone suggest framework that addresses this issue? P.S. There is a framework Qizmt written in C# but I think MapReduce is not good for the above scenario

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  • dojox.enhancedGrid get Selected Row

    - by user256007
    How can I get the Selected Row Object of dojox.enhancedGrid ? I am using selectionMode: 'single' e.g. with Radio Buttons. dijit.byId("gridViewWidget").selection.selectedIndex Returns the rowIndex. But how to get the rowObject of that Index ? I can get the rowNode()But What I need is value of the id column of that Row. Its possible to travarse the HTML DOM returned by rowNode() But Is theer any straight forward way ?

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  • Your thoughts on Best Practices for Scientific Computing?

    - by John Smith
    A recent paper by Wilson et al (2014) pointed out 24 Best Practices for scientific programming. It's worth to have a look. I would like to hear opinions about these points from experienced programmers in scientific data analysis. Do you think these advices are helpful and practical? Or are they good only in an ideal world? Wilson G, Aruliah DA, Brown CT, Chue Hong NP, Davis M, Guy RT, Haddock SHD, Huff KD, Mitchell IM, Plumbley MD, Waugh B, White EP, Wilson P (2014) Best Practices for Scientific Computing. PLoS Biol 12:e1001745. http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001745 Box 1. Summary of Best Practices Write programs for people, not computers. (a) A program should not require its readers to hold more than a handful of facts in memory at once. (b) Make names consistent, distinctive, and meaningful. (c) Make code style and formatting consistent. Let the computer do the work. (a) Make the computer repeat tasks. (b) Save recent commands in a file for re-use. (c) Use a build tool to automate workflows. Make incremental changes. (a) Work in small steps with frequent feedback and course correction. (b) Use a version control system. (c) Put everything that has been created manually in version control. Don’t repeat yourself (or others). (a) Every piece of data must have a single authoritative representation in the system. (b) Modularize code rather than copying and pasting. (c) Re-use code instead of rewriting it. Plan for mistakes. (a) Add assertions to programs to check their operation. (b) Use an off-the-shelf unit testing library. (c) Turn bugs into test cases. (d) Use a symbolic debugger. Optimize software only after it works correctly. (a) Use a profiler to identify bottlenecks. (b) Write code in the highest-level language possible. Document design and purpose, not mechanics. (a) Document interfaces and reasons, not implementations. (b) Refactor code in preference to explaining how it works. (c) Embed the documentation for a piece of software in that software. Collaborate. (a) Use pre-merge code reviews. (b) Use pair programming when bringing someone new up to speed and when tackling particularly tricky problems. (c) Use an issue tracking tool. I'm relatively new to serious programming for scientific data analysis. When I tried to write code for pilot analyses of some of my data last year, I encountered tremendous amount of bugs both in my code and data. Bugs and errors had been around me all the time, but this time it was somewhat overwhelming. I managed to crunch the numbers at last, but I thought I couldn't put up with this mess any longer. Some actions must be taken. Without a sophisticated guide like the article above, I started to adopt "defensive style" of programming since then. A book titled "The Art of Readable Code" helped me a lot. I deployed meticulous input validations or assertions for every function, renamed a lot of variables and functions for better readability, and extracted many subroutines as reusable functions. Recently, I introduced Git and SourceTree for version control. At the moment, because my co-workers are much more reluctant about these issues, the collaboration practices (8a,b,c) have not been introduced. Actually, as the authors admitted, because all of these practices take some amount of time and effort to introduce, it may be generally hard to persuade your reluctant collaborators to comply them. I think I'm asking your opinions because I still suffer from many bugs despite all my effort on many of these practices. Bug fix may be, or should be, faster than before, but I couldn't really measure the improvement. Moreover, much of my time has been invested on defence, meaning that I haven't actually done much data analysis (offence) these days. Where is the point I should stop at in terms of productivity? I've already deployed: 1a,b,c, 2a, 3a,b,c, 4b,c, 5a,d, 6a,b, 7a,7b I'm about to have a go at: 5b,c Not yet: 2b,c, 4a, 7c, 8a,b,c (I could not really see the advantage of using GNU make (2c) for my purpose. Could anyone tell me how it helps my work with MATLAB?)

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  • Green (Screen) Computing

    - by onefloridacoder
    I recently was given an assignment to create a UX where a user could use the up and down arrow keys, as well as the tab and enter keys to move through a Silverlight datagrid that is going be used as part of a high throughput data entry UI. And to be honest, I’ve not trapped key codes since I coded JavaScript a few years ago.  Although the frameworks I’m using made it easy, it wasn’t without some trial and error.    The other thing that bothered me was that the customer tossed this into the use case as they were delivering the use case.  Fine.  I’ll take a whack at anything and beat up myself and beg (I’m not beyond begging for help) the community for help to get something done if I have to. It wasn’t as bad as I thought and I thought I would hopefully save someone a few keystrokes if you wanted to build a green screen for your customer.   Here’s the ValueConverter to handle changing the strings to decimals and then back again.  The value is a nullable valuetype so there are few extra steps to take.  Usually the “ConvertBack()” method doesn’t get addressed but in this case we have two-way binding and the converter needs to ensure that if the user doesn’t enter a value it will remain null when the value is reapplied to the model object’s setter.  1: using System; 2: using System.Windows.Data; 3: using System.Globalization; 4:  5: public class NullableDecimalToStringConverter : IValueConverter 6: { 7: public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) 8: { 9: if (!(((decimal?)value).HasValue)) 10: { 11: return (decimal?)null; 12: } 13: if (!(value is decimal)) 14: { 15: throw new ArgumentException("The value must be of type decimal"); 16: } 17:  18: NumberFormatInfo nfi = culture.NumberFormat; 19: nfi.NumberDecimalDigits = 4; 20:  21: return ((decimal)value).ToString("N", nfi); 22: } 23:  24: public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) 25: { 26: decimal nullableDecimal; 27: decimal.TryParse(value.ToString(), out nullableDecimal); 28:  29: return nullableDecimal == 0 ? null : nullableDecimal.ToString(); 30: } 31: }            The ConvertBack() method uses TryParse to create a value from the incoming string so if the parse fails, we get a null value back, which is what we would expect.  But while I was testing I realized that if the user types something like “2..4” instead of “2.4”, TryParse will fail and still return a null.  The user is getting “puuu-lenty” of eye-candy to ensure they know how many values are affected in this particular view. Here’s the XAML code.   This is the simple part, we just have a DataGrid with one column here that’s bound to the the appropriate ViewModel property with the Converter referenced as well. 1: <data:DataGridTextColumn 2: Header="On-Hand" 3: Binding="{Binding Quantity, 4: Mode=TwoWay, 5: Converter={StaticResource DecimalToStringConverter}}" 6: IsReadOnly="False" /> Nothing too magical here.  Just some XAML to hook things up.   Here’s the code behind that’s handling the DataGridKeyup event.  These are wired to a local/private method but could be converted to something the ViewModel could use, but I just need to get this working for now. 1: // Wire up happens in the constructor 2: this.PicDataGrid.KeyUp += (s, e) => this.HandleKeyUp(e);   1: // DataGrid.BeginEdit fires when DataGrid.KeyUp fires. 2: private void HandleKeyUp(KeyEventArgs args) 3: { 4: if (args.Key == Key.Down || 5: args.Key == Key.Up || 6: args.Key == Key.Tab || 7: args.Key == Key.Enter ) 8: { 9: this.PicDataGrid.BeginEdit(); 10: } 11: }   And that’s it.  The ValueConverter was the biggest problem starting out because I was using an existing converter that didn’t take nullable value types into account.   Once the converter was passing back the appropriate value (null, “#.####”) the grid cell(s) and the model objects started working as I needed them to. HTH.

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  • Cloud computing over Client-server: differences, cons and pros ?

    - by Vimvq1987
    As far as I know, Cloud computing might be a evolution in software architect, and it will replace some current architectures, such as client-server. These two architecture seem to share similarities for me (I know very little about both), but I don't know the differences between them. What are the cons and pros of cloud computing over client-server architecture? Thank you so much.

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  • What Parallel computing APIs take good use of sockets?

    - by Ole Jak
    What Parallel computing APIs take good use of sockets? So my programm uses soskets, what Parallel computing APIs I can use that would help me but will not obligate me to go from sockets to anything else... I mean when we are on claster with some special, not socket infrastructure sistem that API emulates something like socket but uses that infrustructure (so programm peforms much faster then on sockets, but keeps having nice soskets API)

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  • Show Notes: Getting Past the Cloud Hype

    - by Bob Rhubart
    This week’s ArchBeat podcast features an unvarnished bit of conversation culled from a recent virtual meet-up. These meet-ups are informal conversations among architects, many of who have participated in previous ArchBeat programs. There’s no prearranged topic, so the participants talk about whatever is on their minds. The most recent meet-up included Oracle ACE Director Ran Batra, director of cloud computing product development with AT&T, and Daniel Templeton, principal product manager for Oracle Grid Engine, and the man behind Dan T’s GridBlog. The conversation took place at the end of the year – and the end of the decade – a time when most tech publications feature their predictions for the coming year.  I wanted a different spin on that theme, so I asked Ron and Dan to talk about the technologies about which they weren’t all that optimistic.   I found that ten-minute chunk of conversation particularly interesting, so that’s what you’re going to hear this week. Listen Get Social If you have questions or comment for Ron and/or Daniel you can connect via the following: Ron Batra Blog | Twitter | LinkedIn | Oracle Mix | Oracle ACE Profile Daniel Templeton Blog | Twitter | LinkedIn Coming Up Oracle ACE Director Debra Lilley talks about her role in the UKOUG’s development group and that group’s collaboration with Oracle on Oracle Fusion Applications. Dr Frank Munz, author of Middleware and Cloud Computing: Oracle Fusion Middleware on Amazon Web Services and Rackspace Cloud. Stay tuned: http://feeds2.feedburner.com/OtnArch2ArchRSS   del.icio.us Tags: oracle,oracle technology network,archbeat,cloud computing,software architect,podcast Technorati Tags: oracle,oracle technology network,archbeat,cloud computing,software architect,podcast

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  • Java: Preventing array going out of bounds.

    - by Troy
    I'm working on a game of checkers, if you want to read more about you can view it here; http://minnie.tuhs.org/I2P/Assessment/assig2.html When I am doing my test to see if the player is able to get to a certain square on the grid (i.e. +1 +1, +1 -1 .etc) from it's current location, I get an java.lang.ArrayIndexOutOfBoundsException error. This is the code I am using to make the move; public static String makeMove(String move, int playerNumber) { // variables to contain the starting and destination coordinates, subtracting 1 to match array size int colStart = move.charAt(1) - FIRSTCOLREF - 1; int rowStart = move.charAt(0) - FIRSTROWREF - 1; int colEnd = move.charAt(4) - FIRSTCOLREF - 1; int rowEnd = move.charAt(3) - FIRSTROWREF - 1; // variable to contain which player is which char player, enemy; if (playerNumber==1) { player= WHITEPIECE; enemy= BLACKPIECE; } else { player= BLACKPIECE; enemy= WHITEPIECE; } // check that the starting square contains a player piece if (grid [ colStart ] [ rowStart ] == player) { // check that the player is making a diagonal move if (grid [ colEnd ] [ rowEnd ] == grid [ (colStart++) ] [ (rowEnd++) ] && grid [ colEnd ] [ rowEnd ] == grid [ (colStart--) ] [ (rowEnd++) ] && grid [ colEnd ] [ rowEnd ] == grid [ (colStart++) ] [ (rowEnd--) ] && grid [ colEnd ] [ rowEnd ] == grid [ (colStart--) ] [ (rowEnd--) ]) { // check that the destination square is free if (grid [ colEnd ] [ rowEnd ] == BLANK) { grid [ colStart ] [ rowStart ] = BLANK; grid [ colEnd ] [ rowEnd ] = player; } } // check if player is jumping over a piece else if (grid [ colEnd ] [ rowEnd ] == grid [ (colStart+2) ] [ (rowEnd+2) ] && grid [ colEnd ] [ rowEnd ] == grid [ (colStart-2) ] [ (rowEnd+2) ] && grid [ colEnd ] [ rowEnd ] == grid [ (colStart+2) ] [ (rowEnd-2) ] && grid [ colEnd ] [ rowEnd ] == grid [ (colStart-2) ] [ (rowEnd-2) ]) { // check that the piece in between contains an enemy if ((grid [ (colStart++) ] [ (rowEnd++) ] == enemy ) && (grid [ (colStart--) ] [ (rowEnd++) ] == enemy ) && (grid [ (colStart++) ] [ (rowEnd--) ] == enemy ) && (grid [ (colStart--) ] [ (rowEnd--) ] == enemy )) { // check that the destination is free if (grid [ colEnd ] [ rowEnd ] == BLANK) { grid [ colStart ] [ rowStart ] = BLANK; grid [ colEnd ] [ rowEnd ] = player; } } } } I'm not sure how I can prevent the error from happening, what do you recommend?

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  • JqGrid updating grid on add

    - by CSharpAtl
    Scenario: I have three columns in my grid but only one is editable, the other two are filled in on the server side. I am using the built in add functionality of jqGrid and NOT refreshing the grid on successfully add. I would like to have the row added to the grid, like it does automatically, but would like to add it myself because it only adds the one column that is marked 'editable'. I cannot seem to find a way to block the row from being automatically added to the grid, or a way to override the built in add functionality in the grid. My idea was to add the row myself because I will have received back the full row of data back on my submit. Questions: Is there a way to stop the grid from automatically adding the row when I do not want a grid refresh, so that I can manually add all the data for the row? Is it possible to use the built in add button and override the onClick, without digging and and directly figuring out what jqGrid calls the button? Any better ideas on how to accomplish getting the row added to the grid from the server side without doing it all manually...ie. create my own add button, and popup a dialog and handle all the submit functionality? EDIT What would help is if I could stop the grid from auto adding the row...I can deal with doing it myself.

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  • Weblogic domain scale up using EM Grid Control 11gR1

    - by dmitry.nefedkin(at)oracle.com
    As you know a weblogic domain consists of set of servers running independently or in a cluster mode, sharing the distributed resources. And in most environments weblogic  cluster consists of multiple managed servers running simultaneously and working together to provide increased scalability and reliability.  These servers can run on the same machine, or be located on different machines.  It's a common task to increase a cluster's capacity by adding new machines to the cluster to host the new server instances.  You can do it by manually installing weblogic binaries to the new host and use pack/unpack commands to add a managed server to this new host.  But with Enterprise Manager Grid Control 11gR1 (EMGC) there is  another way - Fusion Middleware Domain Scale Up  procedure. I'm going to show you how it works.Here is a picture of  my medrec_oradb weblogic domain, what is registered in EMGC. It contains an admin server and a cluster MedRecCluster with  the single managed server MS1. Both admin and managed servers are on the same host oel46-vmware, it's a virtual machine with OEL 4.6 that runs inside our Oracle VM infrastructure.  And here are the application deployments, note that couple of applications are deployed to the cluster.First of all I have to prepare a new machine that will host new managed sever of my cluster. I created new VM with OEL 5.4 using the corresponding Oracle VM template available in Oracle E-Delivery site for Oracle Linux and Oracle VM and named it wls1032. Next step is to install Oracle EM Grid Control 11gR1 Agent to this new host.  You can download it from the OTN page and install it manually,  or you can use Agent Installation Deployment procedure available in EMGC  (Deployments->Agent Installation->Install Agent). Anyway, when you agent is up and running on the new machine, you will see it in EMGC Console in the Targets->Hosts subtab.Now we are ready to scale up our weblogic domain. Click the Deployments tab in Oracle Enterprise Manager Grid Control, and then click Deployment Procedure. Select a Fusion Middleware Domain Scale Up procedure from the list, and click Schedule Deployment. The first page of the FMW Domain Scale Up Wizard is displayed and you can proceed with the deployment process.Select the domain from list, enter the working directory on the admin server host, and also fill the weblogic credentials for the administration server console and the OS credentials for the  admin server host.  Click Next button.  The next step allows you to configure you domain, to add a new manager server to the cluster you should select the cluster in the tree and click Add Server button. Select the newly added server in a tree, choose the target host and  enter the configuration details of your managed server. You can also add new machine and node manager details.  Please note that you cannot change the values in  Domain Location and Fusion Middleware Home fields, so these locations on the target host will be the same as for the admin server host.   Working directory on the target host should have enough free space to store FMW home binaries and domain configuration files.  In my experience the working directories should have at least 3 Gb of free space.  The last thing you should fill is the OS credentials for the target host. The next steps allows you to schedule the execution of the procedure, it is started immediately in my example. The last step is just a review the configuration for the domain scale up. Click Submit to launch the process. You can track the status of the procedure execution by selecting Deployments->Deployment Procedures->Procedure Completion Status in the EMGC Console.As you can see in the picture below, the procedure consists of the many steps, and I'm going to share my experience about the issues that I had at some of the steps. Please keep in mind that you can always continue the execution from the last successfully completed step by clicking Retry button.Check OUI Prerequisites  step may fail if the target host does  not pass prerequisites checks for Weblogic Server installation such as amount of RAM, linux packages installed, etc. Create FMW Clone Archive step may fail if you do not have enough free space in the working directory on the administration server host.Transfer cloning archive to targets  step  may fail if the EMGC agents on the admin server host or on target host are not secured.   You should secure the agent by issuing ./emctl secure agent  command from $AGENT_HOME/bin directory and entering the agent registration password.Both Transfer cloning archive to targets and Apply Clone at target hosts steps may fail if you do not have enough free space in the working directory on the target host. The most complicated issue I had on the Run Inventory Collection  step. The step failed and I noticed that the agent on the target server is also failed with the following error in the $AGENT_HOME/sysman/log/emagent.trc  log file:2010-12-28 11:50:34,310 Thread-2838952848 ERROR upload: Failed to upload file A0000008.xml: Fatal Error.Response received: 500|ORA-20603: The timezone of the multiagent target (/Farm_Localhost_MedRec_medrec_oradb/medrec_oradb,weblogic_domain)is not consistent with the timezone (America/Los_Angeles) reported by other agents.2010-12-28 11:50:34,310 Thread-2838952848 ERROR upload: 1 Failure(s) in a row or XML error for A0000008.xml, retcode = -6, we give up2010-12-28 11:50:35,552 Thread-2838952848 WARN  upload: FxferSend: received fatal error in header from repository: https://oel46-vmware:1159/em/uploadFATAL_ERROR::500|ORA-20603: The timezone of the multiagent target (/Farm_Localhost_MedRec_medrec_oradb/medrec_oradb,weblogic_domain)is not consistent with the timezone (America/Los_Angeles) reported by other agents.2010-12-28 11:50:35,552 Thread-2838952848 ERROR upload: number of fatal error exceeds the limit 32010-12-28 11:50:35,552 Thread-2838952848 ERROR upload: agent will shutdown now2010-12-28 11:50:35,552 Thread-2838952848 ERROR : Signalled to Exit with status 55. Too many fatal upload failures2010-12-28 11:50:35,552 Thread-2838952848 ERROR upload: 1 Failure(s) in a row or XML error for A0000008.xml, retcode = -6, we give up2010-12-28 11:50:35,552 Thread-3044607680 ERROR main: EMAgent abnormal terminatingI checked the timezone of my domain target inside EMGC repositoryselect timezone_regionfrom mgmt_targets where target_type = 'weblogic_domain'  and display_name = 'medrec_oradb'"TIMEZONE_REGION""America/Los_Angeles"Then checked the timezone of my agents and indeed, they differedselect target_name, timezone_region from mgmt_targets where type_display_name = 'Agent'"TARGET_NAME"    "TIMEZONE_REGION""oel46-vmware:3872"    "America/Los_Angeles""wls1032.imc.fors.ru:3872"    "America/New_York"So I had to change the timezone on the wls1032 host and propagate this changes to the agent and to the EMGC repository. Here was the steps:issued system-config-date command on wls1032.imc.fors.ru  and set timezone to "America/Los_Angeles"propagated the changes to the agent bu executing ./emctl resetTZ agent  command from $AGENT_HOME/bin directoryconnected to EMGC repository as sysman and executed the following PL/SQL block:   begin      mgmt_target.set_agent_tzrgn('wls1032.imc.fors.ru:3872','America/Los_Angeles');      commit;   end;After that I had to clear the pending uploads on wls1032.imc.fors.ru:  rm -r $AGENT_HOME/sysman/emd/state/*  rm -r $AGENT_HOME/sysman/emd/collection/*  rm -r $AGENT_HOME/sysman/emd/upload/*  rm $AGENT_HOME/sysman/emd/lastupld.xml  rm $AGENT_HOME/sysman/emd/agntstmp.txt  $AGENT_HOME/bin/emctl start agent  $AGENT_HOME/bin/emctl clearstate agentThe last part of this solution was to resync the agent in EMGC console by clicking Agent Resynchronization button (please leave "Unblock agent on successful completion of agent resynchronization" checkbox checked in the next screen).After that I issued ./emctl upload command from $AGENT_HOME/bin on the wls1032 host,  and my previous error disappeared,  but I catched another one: EMD upload error: Failed to upload file A0000004.xml: HTTP error.Response received: ERROR-400|Data will be rejected for upload from agent 'https://wls1032.imc.fors.ru:3872/emd/main/', max size limit for direct load exceeded [7544731/5242880]So the uploading XML file size was 7 Mb, and the limit on OMS was 5 Mb.  To increase the max file size limit to 20 Mb I had to connect to the OMS host and execute the following commands from $OMS_HOME/bin directory: ./emctl set property -name em.loader.maxDirectLoadFileSz -value 20971520 -module emoms ./emctl stop oms ./emctl start omsAfter that I issued ./emctl upload command from $AGENT_HOME/bin on the wls1032 one more time and it completed successfully.   The agent uploaded the configuration information to the EMGC  repository and I was able to see the results of my weblogic domain scale-up in EMGC Console.DeploymentsSo, now the weblogic cluster contains 2 managed servers located on the different hosts. This powerful feature of the Enterprise Manager Grid Control  is a part of  the WebLogic Server Management Pack Enterprise Edition.

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  • Sort rectangles in a grid based on a comparison of the center point of each

    - by Mrwolfy
    If I have a grid of rectangles and I move one of the rectangles, say above and to the left of another rectangle, how would I resort the rectangles? Note the rectangles are in an array, so each rectangle has an index and a matching tag. All I really need to do is set the proper index based on the rectangles new center point position within the rectangle, as compared with the center point position of the other rectangles in the grid. Here is what I am doing now in pseudo code (works somewhat, but not accurate): -(void)sortViews:myView { int newIndex; // myView is the view that was moved. [viewsArray removeObject:myView]; [viewsArray enumerate:obj*view]{ if (myView.center.x > view.center.x) { if (myView.center.y > view.center.y) { newIndex = view.tag -1; *stop = YES; } else { newIndex = view.tag +1; *stop = YES; } } else if (myView.center.x < view.center.x) { if (myView.center.y > view.center.y) { newIndex = view.tag -1; *stop = YES; } else { newIndex = view.tag +1; *stop = YES; } } }]; if (newIndex < 0) { newIndex = 0; } else if (newIndex > 5) { newIndex = 5; } [viewsArray insertObject:myView atIndex:newIndex]; [self arrangeGrid]; }

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  • The Proper Use of the VM Role in Windows Azure

    - by BuckWoody
    At the Professional Developer’s Conference (PDC) in 2010 we announced an addition to the Computational Roles in Windows Azure, called the VM Role. This new feature allows a great deal of control over the applications you write, but some have confused it with our full infrastructure offering in Windows Hyper-V. There is a proper architecture pattern for both of them. Virtualization Virtualization is the process of taking all of the hardware of a physical computer and replicating it in software alone. This means that a single computer can “host” or run several “virtual” computers. These virtual computers can run anywhere - including at a vendor’s location. Some companies refer to this as Cloud Computing since the hardware is operated and maintained elsewhere. IaaS The more detailed definition of this type of computing is called Infrastructure as a Service (Iaas) since it removes the need for you to maintain hardware at your organization. The operating system, drivers, and all the other software required to run an application are still under your control and your responsibility to license, patch, and scale. Microsoft has an offering in this space called Hyper-V, that runs on the Windows operating system. Combined with a hardware hosting vendor and the System Center software to create and deploy Virtual Machines (a process referred to as provisioning), you can create a Cloud environment with full control over all aspects of the machine, including multiple operating systems if you like. Hosting machines and provisioning them at your own buildings is sometimes called a Private Cloud, and hosting them somewhere else is often called a Public Cloud. State-ful and Stateless Programming This paradigm does not create a new, scalable way of computing. It simply moves the hardware away. The reason is that when you limit the Cloud efforts to a Virtual Machine, you are in effect limiting the computing resources to what that single system can provide. This is because much of the software developed in this environment maintains “state” - and that requires a little explanation. “State-ful programming” means that all parts of the computing environment stay connected to each other throughout a compute cycle. The system expects the memory, CPU, storage and network to remain in the same state from the beginning of the process to the end. You can think of this as a telephone conversation - you expect that the other person picks up the phone, listens to you, and talks back all in a single unit of time. In “Stateless” computing the system is designed to allow the different parts of the code to run independently of each other. You can think of this like an e-mail exchange. You compose an e-mail from your system (it has the state when you’re doing that) and then you walk away for a bit to make some coffee. A few minutes later you click the “send” button (the network has the state) and you go to a meeting. The server receives the message and stores it on a mail program’s database (the mail server has the state now) and continues working on other mail. Finally, the other party logs on to their mail client and reads the mail (the other user has the state) and responds to it and so on. These events might be separated by milliseconds or even days, but the system continues to operate. The entire process doesn’t maintain the state, each component does. This is the exact concept behind coding for Windows Azure. The stateless programming model allows amazing rates of scale, since the message (think of the e-mail) can be broken apart by multiple programs and worked on in parallel (like when the e-mail goes to hundreds of users), and only the order of re-assembling the work is important to consider. For the exact same reason, if the system makes copies of those running programs as Windows Azure does, you have built-in redundancy and recovery. It’s just built into the design. The Difference Between Infrastructure Designs and Platform Designs When you simply take a physical server running software and virtualize it either privately or publicly, you haven’t done anything to allow the code to scale or have recovery. That all has to be handled by adding more code and more Virtual Machines that have a slight lag in maintaining the running state of the system. Add more machines and you get more lag, so the scale is limited. This is the primary limitation with IaaS. It’s also not as easy to deploy these VM’s, and more importantly, you’re often charged on a longer basis to remove them. your agility in IaaS is more limited. Windows Azure is a Platform - meaning that you get objects you can code against. The code you write runs on multiple nodes with multiple copies, and it all works because of the magic of Stateless programming. you don’t worry, or even care, about what is running underneath. It could be Windows (and it is in fact a type of Windows Server), Linux, or anything else - but that' isn’t what you want to manage, monitor, maintain or license. You don’t want to deploy an operating system - you want to deploy an application. You want your code to run, and you don’t care how it does that. Another benefit to PaaS is that you can ask for hundreds or thousands of new nodes of computing power - there’s no provisioning, it just happens. And you can stop using them quicker - and the base code for your application does not have to change to make this happen. Windows Azure Roles and Their Use If you need your code to have a user interface, in Visual Studio you add a Web Role to your project, and if the code needs to do work that doesn’t involve a user interface you can add a Worker Role. They are just containers that act a certain way. I’ll provide more detail on those later. Note: That’s a general description, so it’s not entirely accurate, but it’s accurate enough for this discussion. So now we’re back to that VM Role. Because of the name, some have mistakenly thought that you can take a Virtual Machine running, say Linux, and deploy it to Windows Azure using this Role. But you can’t. That’s not what it is designed for at all. If you do need that kind of deployment, you should look into Hyper-V and System Center to create the Private or Public Infrastructure as a Service. What the VM Role is actually designed to do is to allow you to have a great deal of control over the system where your code will run. Let’s take an example. You’ve heard about Windows Azure, and Platform programming. You’re convinced it’s the right way to code. But you have a lot of things you’ve written in another way at your company. Re-writing all of your code to take advantage of Windows Azure will take a long time. Or perhaps you have a certain version of Apache Web Server that you need for your code to work. In both cases, you think you can (or already have) code the the software to be “Stateless”, you just need more control over the place where the code runs. That’s the place where a VM Role makes sense. Recap Virtualizing servers alone has limitations of scale, availability and recovery. Microsoft’s offering in this area is Hyper-V and System Center, not the VM Role. The VM Role is still used for running Stateless code, just like the Web and Worker Roles, with the exception that it allows you more control over the environment of where that code runs.

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  • WPF - Grid - updating Row and Column number attached properties on child controls each time a new Ro

    - by ig105
    I have a WPF Grid with a XAML similar to this: <Grid width=200 Height=200 > <Grid.ColumnDefinitions > <ColumnDefinition Width="1*" /> <ColumnDefinition Width="2*" /> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition Height="Auto" /> <RowDefinition Height="Auto" /> <RowDefinition Height="Auto" MinHeight="24" /> </Grid.RowDefinitions> <TextBlock Text="Name" Grid.Row="0" Grid.Column="0"/> <TextBox Grid.Row="0" Grid.Column="1" /> <TextBlock Text="Age" Grid.Row="1" Grid.Column="0"/> <TextBox Grid.Row="1" Grid.Column="1" /> </Grid> I need to add a new row in between existing 2 rows of data, but my worry is that when I add a new row, I will need to manually update Grid.Row attached property in each of the controls that appear in rows below the newly added row. Is there a smarter way of doing this? may be to set Row/Column numbers relative to adjacent Rows/Columns ? Cheers.

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  • Dynamically showing fields to a Dev Express Grid view on windows form

    - by Bhaskar
    In one of windows application in C# , I am using Dev Express Grid view control to bind some data and display it to user. I have custom business objects with properties defined for this purpose.Then I simple set the DataSource of the grid to the list of my custom business objects. A while ago , there came a requirement which means that the columns to be displayed on to the grid will be dynamic. This means I cannot know at design time which fields I will need to display. I was thinking of abandoning setting the DataSource and populating the grid manually by code. But I think this will cause many of the grid's features not to work properly, for example , grouping the data by drag n drop of fields to the header area etc. Is there any way to tell a grid at runtime to skip certain fields from a list of BO's when databinding to the grid ?

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  • Change ExtJS Grid Height in Javascript

    - by williamtroup
    How can I point at the object of a ExtJS Grid and manually set the height (in pixels)? For example, with this same: var grid = new Ext.grid.GridPanel({ store: store, columns: [ {id:'company',header: 'Company', width: 160, sortable: true, dataIndex: 'company'}, {header: 'Price', width: 75, sortable: true, renderer: 'usMoney', dataIndex: 'price'}, {header: 'Change', width: 75, sortable: true, renderer: change, dataIndex: 'change'}, {header: '% Change', width: 75, sortable: true, renderer: pctChange, dataIndex: 'pctChange'}, {header: 'Last Updated', width: 85, sortable: true, renderer: Ext.util.Format.dateRenderer('m/d/Y'), dataIndex: 'lastChange'} ], stripeRows: true, autoExpandColumn: 'company', height: 350, width: 600, title: 'Array Grid', // config options for stateful behavior stateful: true, stateId: 'grid' }); I would i be able to point at the "grid" object and then set the size of the grid? Any help would be fantastic!

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