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• Tips for maximizing Nginx requests/sec?

  - by linkedlinked

  I'm building an analytics package, and project requirements state that I need to support 1 billion hits per day. Yep, "billion". In other words, no less than 12,000 hits per second sustained, and preferably some room to burst. I know I'll need multiple servers for this, but I'm trying to get maximum performance out of each node before "throwing more hardware at it". Right now, I have the hits-tracking portion completed, and well optimized. I pretty much just save the requests straight into Redis (for later processing with Hadoop). The application is Python/Django with a gunicorn for the gateway. My 2GB Ubuntu 10.04 Rackspace server (not a production machine) can serve about 1200 static files per second (benchmarked using Apache AB against a single static asset). To compare, if I swap out the static file link with my tracking link, I still get about 600 requests per second -- I think this means my tracker is well optimized, because it's only a factor of 2 slower than serving static assets. However, when I benchmark with millions of hits, I notice a few things -- No disk usage -- this is expected, because I've turned off all Nginx logs, and my custom code doesn't do anything but save the request details into Redis. Non-constant memory usage -- Presumably due to Redis' memory managing, my memory usage will gradually climb up and then drop back down, but it's never once been my bottleneck. System load hovers around 2-4, the system is still responsive during even my heaviest benchmarks, and I can still manually view http://mysite.com/tracking/pixel with little visible delay while my (other) server performs 600 requests per second. If I run a short test, say 50,000 hits (takes about 2m), I get a steady, reliable 600 requests per second. If I run a longer test (tried up to 3.5m so far), my r/s degrades to about 250. My questions -- a. Does it look like I'm maxing out this server yet? Is 1,200/s static files nginx performance comparable to what others have experienced? b. Are there common nginx tunings for such high-volume applications? I have worker threads set to 64, and gunicorn worker threads set to 8, but tweaking these values doesn't seem to help or harm me much. c. Are there any linux-level settings that could be limiting my incoming connections? d. What could cause my performance to degrade to 250r/s on long-running tests? Again, the memory is not maxing out during these tests, and HDD use is nil. Thanks in advance, all :)

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• Achieving A 1600 x 900 Resolution For (Guest OS) Ubuntu Under (Host OS) Windows 7

  - by panamack

  I am running Ubuntu 11.10 as a guest OS using VirtualBox 4.1.16 installed on Windows 7 Ultimate. On my laptop I'd like to be able to run Ubuntu in full screen mode at 1600 x 900. I only have options within the virtual machine to select 4:3 display settings such as 1600 x 1200, 1440 x 1050 etc. I have guest additions installed. At the windows command prompt, I tried typing: VBoxManage setextradata "Virtual Ubuntu Coursera ESSAAS" "CustomVideoMode1" "1600x900x16" This didn't work, still no 1600 x 900 res available in Ubuntu. I tried this having read the following section of the VirtualBox help (this also says something about a 'video mode hint feature' not sure what this means): 9.7. Advanced display configuration 9.7.1. Custom VESA resolutions Apart from the standard VESA resolutions, the VirtualBox VESA BIOS allows you to add up to 16 custom video modes which will be reported to the guest operating system. When using Windows guests with the VirtualBox Guest Additions, a custom graphics driver will be used instead of the fallback VESA solution so this information does not apply. Additional video modes can be configured for each VM using the extra data facility. The extra data key is called CustomVideoMode with x being a number from 1 to 16. Please note that modes will be read from 1 until either the following number is not defined or 16 is reached. The following example adds a video mode that corresponds to the native display resolution of many notebook computers: VBoxManage setextradata "VM name" "CustomVideoMode1" "1400x1050x16" The VESA mode IDs for custom video modes start at 0x160. In order to use the above defined custom video mode, the following command line has be supplied to Linux: vga = 0x200 | 0x160 vga = 864 For guest operating systems with VirtualBox Guest Additions, a custom video mode can be set using the video mode hint feature. UPDATE 02.06.12 I've just tried creating a new virtual machine using the same original disk image I had been given. This had Guest Additions v 4.1.6 installed and provided me with the 1600 x 900 full screen display I want. It's after I then install Guest Additions v 4.1.16 (the version included with my VirtualBox installation) that my only choices are 4:3 displays e.g. 1600 x 1200. Seems this is the cause.

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• Python cannot go over internet network

  - by user1642826

  I am currently trying to work with python networking and I have reached a bit of a road block. I am not able to network with any computer but localhost, which is kind-of useless with what networking is concerned. I have tried on my local network, from one computer to another, and I have tried over the internet, both fail. The only time I can make it work is if (when running on the server's computer) it's ip is set as 'localhost' or '192.168.2.129' (computers ip). I have spent hours going over opening ports with my isp and have gotten nowhere, so I decided to try this forum. I have my windows firewall down and I have included some pictures of important screen shots. I have no idea what the problem is and this has spanned almost a year of calls to my isp. The computer, modem, and router have all been replaced in that time. Screen shots: import socket import threading import socketserver class ThreadedTCPRequestHandler(socketserver.BaseRequestHandler): def handle(self): data = self.request.recv(1024) cur_thread = threading.current_thread() response = "{}: {}".format(cur_thread.name, data) self.request.sendall(b'worked') class ThreadedTCPServer(socketserver.ThreadingMixIn, socketserver.TCPServer): pass def client(ip, port, message): sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.connect((ip, port)) try: sock.sendall(message) response = sock.recv(1024) print("Received: {}".format(response)) finally: sock.close() if __name__ == "__main__": # Port 0 means to select an arbitrary unused port HOST, PORT = "192.168.2.129", 9000 server = ThreadedTCPServer((HOST, PORT), ThreadedTCPRequestHandler) ip, port = server.server_address # Start a thread with the server -- that thread will then start one # more thread for each request server_thread = threading.Thread(target=server.serve_forever) # Exit the server thread when the main thread terminates server_thread.daemon = True server_thread.start() print("Server loop running in thread:", server_thread.name) ip = '12.34.56.789' print(ip, port) client(ip, port, b'Hello World 1') client(ip, port, b'Hello World 2') client(ip, port, b'Hello World 3') server.shutdown() I do not know where the error is occurring. I get this error: Traceback (most recent call last): File "C:\Users\Dr.Frev\Desktop\serverTest.py", line 43, in <module> client(ip, port, b'Hello World 1') File "C:\Users\Dr.Frev\Desktop\serverTest.py", line 18, in client sock.connect((ip, port)) socket.error: [Errno 10061] No connection could be made because the target machine actively refused it Any help will be greatly appreciated. *if this isn't a proper forum for this, could someone direct me to a more appropriate one.

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• How to make Nginx fire 504 immediately is server is not available?

  - by Georgiy Ivankin

  I have Nginx set up as a load balancer with cookie-based stickiness. The logic is: If the cookie is NOT there, use round-robbing to choose a server from cluster. If the cookie is there, go to the server that is associated with the cookie value. Server is then responsible for setting the cookie. What I want to add is this: If the cookie is there, but server is down, fallback to round-robbing step to choose next available server. So actually I have load balancing and want to add failover support on top of it. I have managed to do that with the help of error_page directive, but it doesn't work as I expected it to. The problem: 504 (and the fallback associated with it) fires only after 30s timeout even if the server is not physically available. So what I want Nginx to do is fire a 504 (or any other error, doesn't matter) immediately (I suppose this means: when TCP connection fails). This is the behavior we can see in browsers: if we go directly to server when it is down, browser immediately tells us that it can't connect. Moreover, Nginx seems to be doing this for 502 error: if I intentionally misconfigure my servers, Nginx fires 502 immediately. Configuration (stripped down to basics): http { upstream my_cluster { server 192.168.73.210:1337; server 192.168.73.210:1338; } map $cookie_myCookie $http_sticky_backend { default 0; value1 192.168.73.210:1337; value2 192.168.73.210:1338; } server { listen 8080; location @fallback { proxy_pass http://my_cluster; } location / { error_page 504 = @fallback; # Create a map of choices # see https://gist.github.com/jrom/1760790 set $test HTTP; if ($http_sticky_backend) { set $test "${test}-STICKY"; } if ($test = HTTP-STICKY) { proxy_pass http://$http_sticky_backend$uri?$args; break; } if ($test = HTTP) { proxy_pass http://my_cluster; break; } return 500 "Misconfiguration"; } } } Disclaimer: I am pretty far from systems administration of any kind, so there may be some basics that I miss here. EDIT: I'm interested in solution with standard free version of Nginx, not Nginx Plus. Thanks.

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• Wrapping a point-to-point link

  - by user3712955

  I'm using a pair of IP radios (non-WiFi) to bridge my office engineering LAN (172.0.0.0/8) to a lab in another building. The radios work fine, but they expose a web management interface I'd like to hide, and they also generate traffic (ARP, STP, and more) that I need to keep off my (very, very clean) LAN segments. I have some ARM-Linux boards (similar to Beagle/Panda/RasPi) running Ubuntu, and I've put one at each end of the link, between the radio and the LAN. Each of the boards has 2 wired Ethernet interfaces, eth0 and eth1. The LAN segments are connected to eth0, and the radios are connected to eth1. I'd like to accomplish the following: Keep radio-originated traffic off my LAN segments! Hide all services provided by the radio (web, ssh, etc.) Transparently pass all traffic between the LAN segments (including things like ARP). The above also applies to the ARM-Linux boards: No stray traffic my LAN from them either! I'd like the system to look like a switch: LAN packets arriving at one eth0 appear at the other. And neither eth0 should have an IP address: The working system should behave like a CAT6 cable with some latency (instead of ARM boards and radios). Unfortunately, I'm confused about how to properly configure the ARM Ubuntu systems. What I'm guessing I need is a bridge on each board (br0?) and a VLAN (vlan0 or eth0.0?) to isolate the LAN traffic from everything else as it passes through the ARM boards and the radios. Then I need some kind of a firewall to block sending anything out eth0 that isn't from the other eth0 (via the VLAN). I've looked at the ip and ebtables commands (especially -t broute). While the concepts sorta-kinda make sense, I'm completely lost in the details. Edit: In the perverse case that a system on one of my LAN segments has the same IP address as one of the radios, or as eth1 on the ARM-Ubuntu boards, a VLAN won't work. Which I believe means I need to tunnel all traffic between the two eth0 interfaces to get that "like a wire" behavior. Help? Finally, I'd like to have a way to temporarily expose services on the ARM boards (ssh) and the radios (web) for maintenance purposes. Ideally, it would expose an IP address with ssh available on port 22. Once connected, I figure I'd start an X11 session and run a browser on the ARM board to access the radios. Or something. I could login via the console to enable/disable this, or perhaps could use a GPIO to trigger a script. I feel I've identified most of the pieces needed to make all this happen, but I have no idea how to combine them to make a working system. Thanks!

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• How can I minimize the amount my router slows down my Internet connection speed?

  - by Lord Torgamus

  Background I'm working with what I assume is a pretty common Internet setup: a cable modem, a wireless router and a few Internet-connected devices. Lately, I've started being more demanding on my Internet connection, and noticed that using my router slows down my download speeds considerably. I just kind of dealt with it until Zune Marketplace on the Xbox 360 told me that a movie was going to take well over ten hours to download, and I just didn't want to wait that long. Good little scientist that I am, I tried to reduce the problem down to one variable. The test As a control, I turned off all the devices in the house that use wireless Internet, and unplugged all the wired devices except for the Xbox. I also power-cycled both the modem and the router. I then tried to download the movie again, and was told that it would still take over ten hours. Next, I unplugged the router, and connected the Xbox directly to the modem. The movie downloaded in just over one hour. As far as I can tell, this means that my ISP, other cable users near me, the remote servers, anything wireless-related and my machines' disk speeds can't be at fault. A similar experiment that replaced the Xbox with a wired laptop produced similar results. To me, this says "the router is responsible for things taking around ten times longer to download." My question I'd still prefer to use the router for a few reasons: it's a pain to connect and disconnect everything every time there's a big file to download direct connection to the modem isn't good for security only one machine can be connected directly to the modem at a time What can I do to have fast connection speeds while still using the router? I don't mind turning other machines off, as long as I don't have to mess with power and ethernet cables. EDIT : After asking this followup question and then this one, I installed dd-wrt on my router, and I seem to be getting higher and more consistent speeds. Perhaps more importantly, my memory use is fairly constant. I know this isn't an answer — which is why I'm not posting it as an answer — but it is how I resolved the situation, and hopefully it'll be helpful for someone.

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• SharePoint 2010 – Central Admin tooling to create host header site collections

  - by eJugnoo

  Just like SharePoint 2007, you can create host-header based site collections in SharePoint 2010 as well. It means, that you do not necessarily need to create a site-collection under a managed path like /sites/, you can create multiple root-level site collections on same web-application/port by using host-header site collections. All you need to do is point your domain or sub-domain to your web-application and create a matching site-collection that you want. But, just like in 2007, it is something that you do by using STSADM, and is not available on Central Admin UI in 2010 as well. Yeah, though you can now also use PowerShell to create one: C:\PS>$w = Get-SPWebApplication http://sitename   C:\PS>New-SPSite http://www.contoso.com -OwnerAlias "DOMAIN\jdoe" -HostHeaderWebApplication $w -Title "Contoso" -Template "STS#0"   This example creates a host header site collection. Because the template is provided, the root Web of this site collection will be created. .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } I’ve been playing with WCM in SharePoint 2010 more and more, and for that I preferred creating hosts file entries for desired domains and create site-collections by those headers – in my dev environment. I used PowerShell initially, but then got interested to build my own UI on Central Admin instead. Developed with Visual Studio 2010 So I used new Visual Studio 2010 tooling to create an empty SharePoint 2010 project. Added an application page (there is no option to add _Admin page item in VS 2010 RC), that got created in Layouts “mapped” folder. Created a new Admin mapped folder for 14-“hive”, and moved my new page there instead. Yes, I didn’t change the base class for page, its just that it runs under _admin, but it is indeed a LayoutsPageBase inherited page. To introduce a action-link in Central Admin console, I created following element: 1: <Elements xmlns="http://schemas.microsoft.com/sharepoint/"> 2: <CustomAction 3: Id="CreateSiteByHeader" 4: Location="Microsoft.SharePoint.Administration.Applications" 5: Title="Create site collections by host header" 6: GroupId="SiteCollections" 7: Sequence="15" 8: RequiredAdmin="Delegated" 9: Description="Create a new top-level web site, by host header" > 10: <UrlAction Url="/_admin/OfficeToolbox/CreateSiteByHeader.aspx" /> 11: </CustomAction> 12: </Elements> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Used Reflector to understand any special code behind createpage.aspx, and created a new for our purpose – CreateSiteByHeader.aspx. From there I quickly created a similar code behind, without all the fancy of Farm Config Wizard handling and dealt with alternate implementations of sealed classes! Goal was to create a professional looking and OOB-type experience. I also added Regex validation to ensure user types a valid domain name as header value. Below is the result…   Release @ Codeplex I’ve released to WSP on OfficeToolbox @ Codeplex, and you can download from here. Hope you find it useful… -- Sharad

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• How To Configure Remote Desktop To Hyper-V Guest Virtual Machines

  - by Brian Jackett

  Configuring Remote Desktop (RDP) from a host Hyper-V machine to a guest virtual machine can be tricky, so this post is dedicated to the issues and resolution steps I went through to allow RDP.  Cutting to the point, below are the things to look for followed by some explanation about my scenario if you care to read.  This is not an exhaustive list of what is required, just the items that were causing problems for my particular scenario. Requirements Allow Remote Desktop Connections in guest OS. The network adapter type must allow communication with host machine (e.g. use an “Internal” virtual adapter.) If running Server 2008 R2 on guest, network discovery mode must be turned on. If running Server 2008 R2 on guest, the services supporting network discovery mode must be running: - DNS Client - Function Discovery Resource Publication - SSDP Discovery - UPnP Device Host My Environment     A quick word about my environment.  I am running Windows Server 2008 R2 with Hyper V on my laptop and numerous guest VMs running Windows Server 2003 R2 or Windows Server 2008 R2.  I run a domain controller VM and then 1 or 2 SharePoint servers depending on my work needs.  I’ve found this setup to work well except when it comes to the display window for my VMs. The Issue     Ever since I began running Hyper-V I haven’t been able to RDP to my guest VMs which means the resolution for my connection windows ha been limited to what the native Hyper-V connections allow.  During personal use I can put the resolution up to 1152 x 864, but during presentations I am usually limited to a measly 800 x 600.  That is until today when I decided to fully investigate why I couldn’t connect via RDP.     First a thank you to John Ross (@johnrossjr), Christina Wheeler (@cwheeler76) and Clayton Cobb (@warrtalon) for various suggestions while I was researching tonight.  As it turns out I had not 1, not 2, but 3 items preventing me from using RDP.  Let’s dig into the requirements above. Allow RDP Connection     This item I had previously taken care of, but it bears repeating because by default Windows Server 2008 R2 does not allow RDP connections.  Change the setting from “Don’t allow…” to whichever “Allow connections…” setting suits your needs.  I chose the less secure option as this is just my dev laptop. Network Adapter Type     When I originally configured my VMs I configured each to use 2 network adapters: one using the physical ethernet adapter for internet use and a virtual private adapter for communication between the VMs.  The connection for the ethernet adapter is an "”External” adapter and thus doesn’t connect between the host and guest.  The virtual private adapter allowed communication ONLY between the VMs and not to my host.  There is a third option “Internal” which allows communication between VMs as well as to the host.  After finding out this distinction I promptly created an Internal network adapter and assigned that to my VMs. Turn On Network Discovery     Seems like a pretty common sense thing, but in order to allow remote desktop connections the target computer must able to be found by the source computer (explained here.)  One of the settings that controls if a computer can be found on the network is aptly named Network Discovery.  By default Windows Server 2008 R2 turns Network Discovery off for security purposes.  To enable it open up the Network and Sharing Center.  Click “Change Advanced Sharing Settings” on the left.  On the following screen select “Turn on network discovery” for the currently used profile and click Save Settings.  You may notice though that your selection to turn on network discovery doesn’t save.  If this is the case then you most likely don’t have the supporting services running (as was my case.) Network Discovery Supporting Services     There are a total of 4 services (listed again below) that need to be running before you can turn on network discovery (explained here.)  The below images highlight these services.  In my guest VM I found that I had DNS Client already running while the other 3 were disabled.  I set them all to enabled and started the ones that were stopped.  After this change I returned to the Sharing settings screen and found that Network Discovery was turned on.  I’m not sure whether this was picking up my attempt to turn it on previously or if starting those services turned it on.  Either way the end result was a success. - DNS Client - Function Discovery Resource Publication - SSDP Discovery - UPnP Device Host Before and After Results     The first image is the smaller square shaped viewing window used by the Hyper-V native connection.  The second is the full-screen RDP connection in all its widescreen glory. Conclusion     Over the past few months I’ve found Hyper-V to be very useful for virtualizing my development environments, but I’ve also had a steep learning curve to get various items configured just right.  Allowing RDP connections to guest VMs was one area that I hadn’t been able to get right for the longest time.  Now that I resolved these issues I hope that others can avoid the pitfalls that I ran into.  If you know of any other items I left off feel free to let me know.        -Frog Out   Links Turning on Network Discovery http://sqlblog.com/blogs/john_paul_cook/archive/2009/08/15/remote-desktop-connection-on-windows-server-2008-r2.aspx Services required for Network Discovery http://social.technet.microsoft.com/Forums/en-US/winservergen/thread/2e1fea01-3f2b-4c46-a631-a8db34ed4f84

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• MEF CompositionInitializer for WPF

  - by Reed

  The Managed Extensibility Framework is an amazingly useful addition to the .NET Framework.  I was very excited to see System.ComponentModel.Composition added to the core framework.  Personally, I feel that MEF is one tool I’ve always been missing in my .NET development. Unfortunately, one perfect scenario for MEF tends to fall short of it’s full potential is in Windows Presentation Foundation development.  In particular, there are many times when the XAML parser constructs objects in WPF development, which makes composition of those parts difficult.  The current release of MEF (Preview Release 9) addresses this for Silverlight developers via System.ComponentModel.Composition.CompositionInitializer.  However, there is no equivalent class for WPF developers. The CompositionInitializer class provides the means for an object to compose itself.  This is very useful with WPF and Silverlight development, since it allows a View, such as a UserControl, to be generated via the standard XAML parser, and still automatically pull in the appropriate ViewModel in an extensible manner.  Glenn Block has demonstrated the usage for Silverlight in detail, but the same issues apply in WPF. As an example, let’s take a look at a very simple case.  Take the following XAML for a Window: <Window x:Class="WpfApplication1.MainView" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="MainWindow" Height="220" Width="300"> <Grid> <TextBlock Text="{Binding TheText}" /> </Grid> </Window> This does nothing but create a Window, add a simple TextBlock control, and use it to display the value of our “TheText” property in our DataContext class.  Since this is our main window, WPF will automatically construct and display this Window, so we need to handle constructing the DataContext and setting it ourselves. We could do this in code or in XAML, but in order to do it directly, we would need to hard code the ViewModel type directly into our XAML code, or we would need to construct the ViewModel class and set it in the code behind.  Both have disadvantages, and the disadvantages grow if we’re using MEF to compose our ViewModel. Ideally, we’d like to be able to have MEF construct our ViewModel for us.  This way, it can provide any construction requirements for our ViewModel via [ImportingConstructor], and it can handle fully composing the imported properties on our ViewModel.  CompositionInitializer allows this to occur. We use CompositionInitializer within our View’s constructor, and use it for self-composition of our View.  Using CompositionInitializer, we can modify our code behind to: public partial class MainView : Window { public MainView() { InitializeComponent(); CompositionInitializer.SatisfyImports(this); } [Import("MainViewModel")] public object ViewModel { get { return this.DataContext; } set { this.DataContext = value; } } } We then can add an Export on our ViewModel class like so: [Export("MainViewModel")] public class MainViewModel { public string TheText { get { return "Hello World!"; } } } MEF will automatically compose our application, decoupling our ViewModel injection to the DataContext of our View until runtime.  When we run this, we’ll see: There are many other approaches for using MEF to wire up the extensible parts within your application, of course.  However, any time an object is going to be constructed by code outside of your control, CompositionInitializer allows us to continue to use MEF to satisfy the import requirements of that object. In order to use this from WPF, I’ve ported the code from MEF Preview 9 and Glenn Block’s (now obsolete) PartInitializer port to Windows Presentation Foundation.  There are some subtle changes from the Silverlight port, mainly to handle running in a desktop application context.  The default behavior of my port is to construct an AggregateCatalog containing a DirectoryCatalog set to the location of the entry assembly of the application.  In addition, if an “Extensions” folder exists under the entry assembly’s directory, a second DirectoryCatalog for that folder will be included.  This behavior can be overridden by specifying a CompositionContainer or one or more ComposablePartCatalogs to the System.ComponentModel.Composition.Hosting.CompositionHost static class prior to the first use of CompositionInitializer. Please download CompositionInitializer and CompositionHost for VS 2010 RC, and contact me with any feedback. Composition.Initialization.Desktop.zip Edit on 3/29: Glenn Block has since updated his version of CompositionInitializer (and ExportFactory<T>!), and made it available here: http://cid-f8b2fd72406fb218.skydrive.live.com/self.aspx/blog/Composition.Initialization.Desktop.zip This is a .NET 3.5 solution, and should soon be pushed to CodePlex, and made available on the main MEF site.

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• Using Unity – Part 3

  - by nmarun

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

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• Secure wipe of a hard drive using WinPE.

  - by Derek Meier

  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;} The wiping of a hard drive is typically seen as fairly trivial.  There are tons of applications out there that will do it for you.  Point àClickàGlobal-Thermo Nuclear War. However, these applications are typically expensive or unreliable.  Plus, if you have a laptop or lack a secondary computer to put the hard drive into – how on earth do you wipe it quickly and easily while still conforming to a 7 pass rule (this means that every possible bit on the hard drive is set to 0 and then to 1 seven times in a row)?  Yes, one pass should be enough – as turning every bit from a 1 to a zero will wipe the data from existence.  But, we’re dealing with tinfoil hat wearing types here people.  DOD standards dictate at least 3 passes, and typically 7 is the preferred amount.  I’m not going to argue about data recovery.  I have been told to use 7 passes, and so I will.  So say we all! Quite some time ago I used to make a BartPE XP-based boot cd for the original purpose of securely wiping data.  I loved BartPE and integrated so many plugins into my builds that I could do pretty much anything directly from CD.  Reset passwords, uninstall security updates, wipe drives, chkdsk, remove spyware, install Windows, etc.  However, with the newer multi-core systems and new chipsets coming out from vendors, I found that BartPE was rather difficult to keep up to date.  I have since switched to WinPE 3.0 (Windows Preinstallation Environment). http://technet.microsoft.com/en-us/library/cc748933(WS.10).aspx  It is fairly simple to create your own CD, and I have made a few helpful scripts to easily integrate drivers and rebuild the ISO file for you.  I’ll cover making your own boot CD utilizing WinPE 3.0 in a later post – I can talk about WinPE forever and need to collect my thoughts!!  My wife loves talking about WinPE almost as much as talking about Doctor Who.  Wait, did I say loves?  Hmmmm, I may have meant loathes. The topic at hand?  Right. Wiping a drive! I must have drunk too much coffee this morning.  I like to use a simple batch script that calls a combination of diskpart.exe from Microsoft® and Sdelete.exe created by our friend Mark Russinovich. http://technet.microsoft.com/en-us/sysinternals/bb897443.aspx All of the following files are located within the same directory on my WinPE boot CD. Here are the contents of wipe_me.bat, script.txt and sdelete.reg. Wipe_me.bat:   @echo off echo. echo     I will completely wipe the local hard drives using echo     7 individual wipes. The data will NOT echo     be recoverable.  I will begin after you pause echo. echo Preparing to partition and format disk. Diskpart.exe /s "script.txt" REM I was annoyed by not having a completely automated script – and Sdelete wants you to accept the license agreement. So, I added a registry file to skip doing that. regedit /S sdelete.reg rem sdelete options selected are: -p (passes) -c (zero free space) -s (recurse through subdirectories, if any) -z (clean free space) [drive letter] sdelete.exe -p 7 -c -s -z c: echo. echo Pass seven complete. echo. echo Wiping complete. Pause exit script.txt: list disk select disk 0 clean create partition primary select partition 1 active format FS=NTFS LABEL="New Volume" QUICK assign letter=c exit *Notes: This script assumes one local hard drive – change the script as you see fit for your environment.  The clean command will overwrite the master boot record and any hidden sector information – so be careful!   sdelete.reg: Windows Registry Editor Version 5.00 [HKEY_CURRENT_USER\Software\Sysinternals\SDelete] "EulaAccepted"=dword:00000001   With a combination of WinPE, sdelete.exe and your friendly neighborhood text editor you can begin wiping drives as quickly and easily as possible!  I hope this helps, I get asked this a lot in my line of work. Best of luck, Derek

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• SQL SERVER – Enumerations in Relational Database – Best Practice

  - by pinaldave

  Marko Parkkola This article has been submitted by Marko Parkkola, Data systems designer at Saarionen Oy, Finland. Marko is excellent developer and always thinking at next level. You can read his earlier comment which created very interesting discussion here: SQL SERVER- IF EXISTS(Select null from table) vs IF EXISTS(Select 1 from table). I must express my special thanks to Marko for sending this best practice for Enumerations in Relational Database. He has really wrote excellent piece here and welcome comments here. Enumerations in Relational Database This is a subject which is very basic thing in relational databases but often not very well understood and sometimes badly implemented. There are of course many ways to do this but I concentrate only two cases, one which is “the right way” and one which is definitely wrong way. The concept Let’s say we have table Person in our database. Person has properties/fields like Firstname, Lastname, Birthday and so on. Then there’s a field that tells person’s marital status and let’s name it the same way; MaritalStatus. Now MaritalStatus is an enumeration. In C# I would definitely make it an enumeration with values likes Single, InRelationship, Married, Divorced. Now here comes the problem, SQL doesn’t have enumerations. The wrong way This is, in my opinion, absolutely the wrong way to do this. It has one upside though; you’ll see the enumeration’s description instantly when you do simple SELECT query and you don’t have to deal with mysterious values. There’s plenty of downsides too and one would be database fragmentation. Consider this (I’ve left all indexes and constraints out of the query on purpose). CREATE TABLE [dbo].[Person] ( [Firstname] NVARCHAR(100), [Lastname] NVARCHAR(100), [Birthday] datetime, [MaritalStatus] NVARCHAR(10) ) You have nvarchar(20) field in the table that tells the marital status. Obvious problem with this is that what if you create a new value which doesn’t fit into 20 characters? You’ll have to come and alter the table. There are other problems also but I’ll leave those for the reader to think about. The correct way Here’s how I’ve done this in many projects. This model still has one problem but it can be alleviated in the application layer or with CHECK constraints if you like. First I will create a namespace table which tells the name of the enumeration. I will add one row to it too. I’ll write all the indexes and constraints here too. CREATE TABLE [CodeNamespace] ( [Id] INT IDENTITY(1, 1), [Name] NVARCHAR(100) NOT NULL, CONSTRAINT [PK_CodeNamespace] PRIMARY KEY ([Id]), CONSTRAINT [IXQ_CodeNamespace_Name] UNIQUE NONCLUSTERED ([Name]) ) GO INSERT INTO [CodeNamespace] SELECT 'MaritalStatus' GO Then I create a table that holds the actual values and which reference to namespace table in order to group the values under different namespaces. I’ll add couple of rows here too. CREATE TABLE [CodeValue] ( [CodeNamespaceId] INT NOT NULL, [Value] INT NOT NULL, [Description] NVARCHAR(100) NOT NULL, [OrderBy] INT, CONSTRAINT [PK_CodeValue] PRIMARY KEY CLUSTERED ([CodeNamespaceId], [Value]), CONSTRAINT [FK_CodeValue_CodeNamespace] FOREIGN KEY ([CodeNamespaceId]) REFERENCES [CodeNamespace] ([Id]) ) GO -- 1 is the 'MaritalStatus' namespace INSERT INTO [CodeValue] SELECT 1, 1, 'Single', 1 INSERT INTO [CodeValue] SELECT 1, 2, 'In relationship', 2 INSERT INTO [CodeValue] SELECT 1, 3, 'Married', 3 INSERT INTO [CodeValue] SELECT 1, 4, 'Divorced', 4 GO Now there’s four columns in CodeValue table. CodeNamespaceId tells under which namespace values belongs to. Value tells the enumeration value which is used in Person table (I’ll show how this is done below). Description tells what the value means. You can use this, for example, column in UI’s combo box. OrderBy tells if the values needs to be ordered in some way when displayed in the UI. And here’s the Person table again now with correct columns. I’ll add one row here to show how enumerations are to be used. CREATE TABLE [dbo].[Person] ( [Firstname] NVARCHAR(100), [Lastname] NVARCHAR(100), [Birthday] datetime, [MaritalStatus] INT ) GO INSERT INTO [Person] SELECT 'Marko', 'Parkkola', '1977-03-04', 3 GO Now I said earlier that there is one problem with this. MaritalStatus column doesn’t have any database enforced relationship to the CodeValue table so you can enter any value you like into this field. I’ve solved this problem in the application layer by selecting all the values from the CodeValue table and put them into a combobox / dropdownlist (with Value field as value and Description as text) so the end user can’t enter any illegal values; and of course I’ll check the entered value in data access layer also. I said in the “The wrong way” section that there is one benefit to it. In fact, you can have the same benefit here by using a simple view, which I schema bound so you can even index it if you like. CREATE VIEW [dbo].[Person_v] WITH SCHEMABINDING AS SELECT p.[Firstname], p.[Lastname], p.[BirthDay], c.[Description] MaritalStatus FROM [dbo].[Person] p JOIN [dbo].[CodeValue] c ON p.[MaritalStatus] = c.[Value] JOIN [dbo].[CodeNamespace] n ON n.[Id] = c.[CodeNamespaceId] AND n.[Name] = 'MaritalStatus' GO -- Select from View SELECT * FROM [dbo].[Person_v] GO This is excellent write up byMarko Parkkola. Do you have this kind of design setup at your organization? Let us know your opinion. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Best Practices, Database, DBA, Readers Contribution, Software Development, SQL, SQL Authority, SQL Documentation, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Creating packages in code – Execute SQL Task

  The Execute SQL Task is for obvious reasons very well used, so I thought if you are building packages in code the chances are you will be using it. Using the task basic features of the task are quite straightforward, add the task and set some properties, just like any other. When you start interacting with variables though it can be a little harder to grasp so these samples should see you through. Some of these more advanced features are explained in much more detail in our ever popular post The Execute SQL Task, here I’ll just be showing you how to implement them in code. The abbreviated code blocks below demonstrate the different features of the task. The complete code has been encapsulated into a sample class which you can download (ExecSqlPackage.cs). Each feature described has its own method in the sample class which is mentioned after the code block. This first sample just shows adding the task, setting the basic properties for a connection and of course an SQL statement. Package package = new Package(); // Add the SQL OLE-DB connection ConnectionManager sqlConnection = AddSqlConnection(package, "localhost", "master"); // Add the SQL Task package.Executables.Add("STOCK:SQLTask"); // Get the task host wrapper TaskHost taskHost = package.Executables[0] as TaskHost; // Set required properties taskHost.Properties["Connection"].SetValue(taskHost, sqlConnection.ID); taskHost.Properties["SqlStatementSource"].SetValue(taskHost, "SELECT * FROM sysobjects"); For the full version of this code, see the CreatePackage method in the sample class. The AddSqlConnection method is a helper method that adds an OLE-DB connection to the package, it is of course in the sample class file too. Returning a single value with a Result Set The following sample takes a different approach, getting a reference to the ExecuteSQLTask object task itself, rather than just using the non-specific TaskHost as above. Whilst it means we need to add an extra reference to our project (Microsoft.SqlServer.SQLTask) it makes coding much easier as we have compile time validation of any property and types we use. For the more complex properties that is very valuable and saves a lot of time during development. The query has also been changed to return a single value, one row and one column. The sample shows how we can return that value into a variable, which we also add to our package in the code. To do this manually you would set the Result Set property on the General page to Single Row and map the variable on the Result Set page in the editor. Package package = new Package(); // Add the SQL OLE-DB connection ConnectionManager sqlConnection = AddSqlConnection(package, "localhost", "master"); // Add the SQL Task package.Executables.Add("STOCK:SQLTask"); // Get the task host wrapper TaskHost taskHost = package.Executables[0] as TaskHost; // Add variable to hold result value package.Variables.Add("Variable", false, "User", 0); // Get the task object ExecuteSQLTask task = taskHost.InnerObject as ExecuteSQLTask; // Set core properties task.Connection = sqlConnection.Name; task.SqlStatementSource = "SELECT id FROM sysobjects WHERE name = 'sysrowsets'"; // Set single row result set task.ResultSetType = ResultSetType.ResultSetType_SingleRow; // Add result set binding, map the id column to variable task.ResultSetBindings.Add(); IDTSResultBinding resultBinding = task.ResultSetBindings.GetBinding(0); resultBinding.ResultName = "id"; resultBinding.DtsVariableName = "User::Variable"; For the full version of this code, see the CreatePackageResultVariable method in the sample class. The other types of Result Set behaviour are just a variation on this theme, set the property and map the result binding as required. Parameter Mapping for SQL Statements This final example uses a parameterised SQL statement, with the coming from a variable. The syntax varies slightly between connection types, as explained in the Working with Parameters and Return Codes in the Execute SQL Taskhelp topic, but OLE-DB is the most commonly used, for which a question mark is the parameter value placeholder. Package package = new Package(); // Add the SQL OLE-DB connection ConnectionManager sqlConnection = AddSqlConnection(package, ".", "master"); // Add the SQL Task package.Executables.Add("STOCK:SQLTask"); // Get the task host wrapper TaskHost taskHost = package.Executables[0] as TaskHost; // Get the task object ExecuteSQLTask task = taskHost.InnerObject as ExecuteSQLTask; // Set core properties task.Connection = sqlConnection.Name; task.SqlStatementSource = "SELECT id FROM sysobjects WHERE name = ?"; // Add variable to hold parameter value package.Variables.Add("Variable", false, "User", "sysrowsets"); // Add input parameter binding task.ParameterBindings.Add(); IDTSParameterBinding parameterBinding = task.ParameterBindings.GetBinding(0); parameterBinding.DtsVariableName = "User::Variable"; parameterBinding.ParameterDirection = ParameterDirections.Input; parameterBinding.DataType = (int)OleDBDataTypes.VARCHAR; parameterBinding.ParameterName = "0"; parameterBinding.ParameterSize = 255; For the full version of this code, see the CreatePackageParameterVariable method in the sample class. You’ll notice the data type has to be specified for the parameter IDTSParameterBinding .DataType Property, and these type codes are connection specific too. My enumeration I wrote several years ago is shown below was probably done by reverse engineering a package and also the API header file, but I recently found a very handy post that covers more connections as well for exactly this, Setting the DataType of IDTSParameterBinding objects (Execute SQL Task). /// <summary> /// Enumeration of OLE-DB types, used when mapping OLE-DB parameters. /// </summary> private enum OleDBDataTypes { BYTE = 0x11, CURRENCY = 6, DATE = 7, DB_VARNUMERIC = 0x8b, DBDATE = 0x85, DBTIME = 0x86, DBTIMESTAMP = 0x87, DECIMAL = 14, DOUBLE = 5, FILETIME = 0x40, FLOAT = 4, GUID = 0x48, LARGE_INTEGER = 20, LONG = 3, NULL = 1, NUMERIC = 0x83, NVARCHAR = 130, SHORT = 2, SIGNEDCHAR = 0x10, ULARGE_INTEGER = 0x15, ULONG = 0x13, USHORT = 0x12, VARCHAR = 0x81, VARIANT_BOOL = 11 } Download Sample code ExecSqlPackage.cs (10KB)

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

  - by Reed

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

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• C# 4.0: Dynamic Programming

  - by Paulo Morgado

  The major feature of C# 4.0 is dynamic programming. Not just dynamic typing, but dynamic in broader sense, which means talking to anything that is not statically typed to be a .NET object. Dynamic Language Runtime The Dynamic Language Runtime (DLR) is piece of technology that unifies dynamic programming on the .NET platform, the same way the Common Language Runtime (CLR) has been a common platform for statically typed languages. The CLR always had dynamic capabilities. You could always use reflection, but its main goal was never to be a dynamic programming environment and there were some features missing. The DLR is built on top of the CLR and adds those missing features to the .NET platform. The Dynamic Language Runtime is the core infrastructure that consists of: Expression Trees The same expression trees used in LINQ, now improved to support statements. Dynamic Dispatch Dispatches invocations to the appropriate binder. Call Site Caching For improved efficiency. Dynamic languages and languages with dynamic capabilities are built on top of the DLR. IronPython and IronRuby were already built on top of the DLR, and now, the support for using the DLR is being added to C# and Visual Basic. Other languages built on top of the CLR are expected to also use the DLR in the future. Underneath the DLR there are binders that talk to a variety of different technologies: .NET Binder Allows to talk to .NET objects. JavaScript Binder Allows to talk to JavaScript in SilverLight. IronPython Binder Allows to talk to IronPython. IronRuby Binder Allows to talk to IronRuby. COM Binder Allows to talk to COM. Whit all these binders it is possible to have a single programming experience to talk to all these environments that are not statically typed .NET objects. The dynamic Static Type Let’s take this traditional statically typed code: Calculator calculator = GetCalculator(); int sum = calculator.Sum(10, 20); Because the variable that receives the return value of the GetCalulator method is statically typed to be of type Calculator and, because the Calculator type has an Add method that receives two integers and returns an integer, it is possible to call that Sum method and assign its return value to a variable statically typed as integer. Now lets suppose the calculator was not a statically typed .NET class, but, instead, a COM object or some .NET code we don’t know he type of. All of the sudden it gets very painful to call the Add method: object calculator = GetCalculator(); Type calculatorType = calculator.GetType(); object res = calculatorType.InvokeMember("Add", BindingFlags.InvokeMethod, null, calculator, new object[] { 10, 20 }); int sum = Convert.ToInt32(res); And what if the calculator was a JavaScript object? ScriptObject calculator = GetCalculator(); object res = calculator.Invoke("Add", 10, 20); int sum = Convert.ToInt32(res); For each dynamic domain we have a different programming experience and that makes it very hard to unify the code. With C# 4.0 it becomes possible to write code this way: dynamic calculator = GetCalculator(); int sum = calculator.Add(10, 20); You simply declare a variable who’s static type is dynamic. dynamic is a pseudo-keyword (like var) that indicates to the compiler that operations on the calculator object will be done dynamically. The way you should look at dynamic is that it’s just like object (System.Object) with dynamic semantics associated. Anything can be assigned to a dynamic. dynamic x = 1; dynamic y = "Hello"; dynamic z = new List<int> { 1, 2, 3 }; At run-time, all object will have a type. In the above example x is of type System.Int32. When one or more operands in an operation are typed dynamic, member selection is deferred to run-time instead of compile-time. Then the run-time type is substituted in all variables and normal overload resolution is done, just like it would happen at compile-time. The result of any dynamic operation is always dynamic and, when a dynamic object is assigned to something else, a dynamic conversion will occur. Code Resolution Method double x = 1.75; double y = Math.Abs(x); compile-time double Abs(double x) dynamic x = 1.75; dynamic y = Math.Abs(x); run-time double Abs(double x) dynamic x = 2; dynamic y = Math.Abs(x); run-time int Abs(int x) The above code will always be strongly typed. The difference is that, in the first case the method resolution is done at compile-time, and the others it’s done ate run-time. IDynamicMetaObjectObject The DLR is pre-wired to know .NET objects, COM objects and so forth but any dynamic language can implement their own objects or you can implement your own objects in C# through the implementation of the IDynamicMetaObjectProvider interface. When an object implements IDynamicMetaObjectProvider, it can participate in the resolution of how method calls and property access is done. The .NET Framework already provides two implementations of IDynamicMetaObjectProvider: DynamicObject : IDynamicMetaObjectProvider The DynamicObject class enables you to define which operations can be performed on dynamic objects and how to perform those operations. For example, you can define what happens when you try to get or set an object property, call a method, or perform standard mathematical operations such as addition and multiplication. ExpandoObject : IDynamicMetaObjectProvider The ExpandoObject class enables you to add and delete members of its instances at run time and also to set and get values of these members. This class supports dynamic binding, which enables you to use standard syntax like sampleObject.sampleMember, instead of more complex syntax like sampleObject.GetAttribute("sampleMember").

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• Java Embedded @ JavaOne: Q & A

  - by terrencebarr

  There has been a lot of interest in Java Embedded @ JavaOne since it was announced a short while ago (see my previous post). As this is a new conference we did get a number of questions regarding the conference. So we put together a brief Q & A on audience focus, dates, registrations, pricing, submissions, etc. Hope this helps and, remember, the Call for Papers ends next week, Jul 18th 2012! Cheers, – Terrence    Java Embedded @ JavaOne : Q & A  Q. Where can I learn more about “Java Embedded @ JavaOne”? A. Please visit: http://oracle.com/javaone/embedded Q. What is the purpose of “Java Embedded @ JavaOne”? A. This net-new event is designed to provide business and technical decision makers, as well as Java embedded ecosystem partners, a unique occasion to come together and learn about how they can use Java Embedded technologies for new business opportunities. Q. What broad audiences would benefit by attending “Java Embedded @ JavaOne”? A. Java licensees; Government agencies; ISVs, Device Manufacturers; Service Providers such as Telcos, Utilities, Healthcare, Energy, Smart Grid/Smart Metering; Automotive/Telematics; Home/Building Automation; Factory Automation; Media/TV; and Payment vendors. Q. What business titles would benefit by attending “Java Embedded @ JavaOne”? A. The ideal audience for this event is business and technical decision makers (e.g. System Integrators, CTO, CXO, Chief Architects/Architects, Business Development Managers, Project Managers, Purchasing managers, Technical Leads, Senior Decision Makers, Practice Leads, R&D Heads, and Development Managers/Leads). Q. When is “Java Embedded @ JavaOne” taking place? A. The event takes place on Wednesday, Oct. 3th through Thursday, Oct. 4th. Q. Where is “Java Embedded @ JavaOne” taking place? A. The event takes place in the Hotel Nikko. Q. Won’t “Java Embedded @ JavaOne” impact the flagship JavaOne conference since the Hotel Nikko is one of the 3 flagship JavaOne conference’s venue hotels? A. No. Separate space in the Hotel Nikko will be used for “Java Embedded @ JavaOne” and will in no way impact scale and scope of the flagship JavaOne conference’s content mix. Q. Will there be a call for papers for “Java Embedded @ JavaOne”? A. Yes.  The call for papers has started but is ONLY for business focused submissions. Q. What type of business submissions can I make for “Java Embedded @ JavaOne”? A. We are accepting 3 types of business submissions: Best Practices: Java Embedded business solutions, methods, and techniques that consistently show results superior to those achieved with other means, as well as discussions on how Java Embedded can improve business operations, and increase competitive differentiation and profitability. Case Studies: Discussions with Oracle customers and partners that describe the unique business drivers that convinced them to implement Java Embedded as part of an infrastructure technology mix. The discussions will highlight the issues they faced, the decision making involved, and the implementation choices made to create value and improve business differentiation. Panel: Moderator-driven open discussion focused on the emerging opportunities Java Embedded offers businesses, as well as other topics such as strategy, overcoming common challenges, etc. Q. What is the call for papers timeline for “Java Embedded @ JavaOne”? A. The timeline is as follows: CFP Launched – June 18th Deadline for submissions – July 18th Notifications (Accepts/Declines) – week of July 29th Deadline for speakers to accept speaker invitation – August 10th Presentations due for review – August 31st Q. Where can I find more call for paper details for “Java Embedded @ JavaOne”? A. Please go to: http://www.oracle.com/javaone/embedded/call-for-papers/information/index.html Q. How much does it cost to attend “Java Embedded @ JavaOne”? A. The cost to attend is: $595.00 U.S. — Early Bird (Launch date – July 13, 2012) $795.00 U.S. — Pre-Registration (July 14 – September 28, 2012) $995.00 U.S. — Onsite Registration (September 29 – October 4, 2012) Q. Can an attendee of the flagship JavaOne event and Oracle OpenWorld attend “Java Embedded @ JavaOne”? ?A. Yes.  Attendees of both the flagship JavaOne event and Oracle OpenWorld can attend “Java Embedded @ JavaOne” by purchasing a $100.00 U.S. upgrade to their full conference pass. Filed under: Mobile & Embedded Tagged: Call for Papers, Java Embedded @ JavaOne, JavaOne San Francisco

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• The Challenge with HTML5 – In Pictures

  - by dwahlin

  I love working with Web technologies and am looking forward to the new functionality that HTML5 will ultimately bring to the table (some of which can be used today). Having been through the div versus layer battle back in the IE4 and Netscape 4 days I think we’re headed down that road again as a result of browsers implementing features differently. I’ve been spending a lot of time researching and playing around with HTML5 samples and features (mainly because we’re already seeing demand for training on HTML5) and there’s a lot of great stuff there that will truly revolutionize web applications as we know them. However, browsers just aren’t there yet and many people outside of the development world don’t really feel a need to upgrade their browser if it’s working reasonably well (Mom and Dad come to mind) so it’s going to be awhile. There’s a nice test site at http://www.HTML5Test.com that runs through different HTML5 features and scores how well they’re supported. They don’t test for everything and are very clear about that on the site: “The HTML5 test score is only an indication of how well your browser supports the upcoming HTML5 standard and related specifications. It does not try to test all of the new features offered by HTML5, nor does it try to test the functionality of each feature it does detect. Despite these shortcomings we hope that by quantifying the level of support users and web developers will get an idea of how hard the browser manufacturers work on improving their browsers and the web as a development platform. The score is calculated by testing for the many new features of HTML5. Each feature is worth one or more points. Apart from the main HTML5 specification and other specifications created the W3C HTML Working Group, this test also awards points for supporting related drafts and specifications. Some of these specifications were initially part of HTML5, but are now further developed by other W3C working groups. WebGL is also part of this test despite not being developed by the W3C, because it extends the HTML5 canvas element with a 3d context. The test also awards bonus points for supporting audio and video codecs and supporting SVG or MathML embedding in a plain HTML document. These test do not count towards the total score because HTML5 does not specify any required audio or video codec. Also SVG and MathML are not required by HTML5, the specification only specifies rules for how such content should be embedded inside a plain HTML file. Please be aware that the specifications that are being tested are still in development and could change before receiving an official status. In the future new tests will be added for the pieces of the specification that are currently still missing. The maximum number of points that can be scored is 300 at this moment, but this is a moving goalpost.” It looks like their tests haven’t been updated since June, but the numbers are pretty scary as a developer because it means I’m going to have to do a lot of browser sniffing before assuming a particular feature is available to use. Not that much different from what we do today as far as browser sniffing you say? I’d have to disagree since HTML5 takes it to a whole new level. In today’s world we have script libraries such as jQuery (my personal favorite), Prototype, script.aculo.us, YUI Library, MooTools, etc. that handle the heavy lifting for us. Until those libraries handle all of the key HTML5 features available it’s going to be a challenge. Certain features such as Canvas are supported fairly well across most of the major browsers while other features such as audio and video are hit or miss depending upon what codec you want to use. Run the tests yourself to see what passes and what fails for different browsers. You can also view the HTML5 Test Suite Conformance Results at http://test.w3.org/html/tests/reporting/report.htm (a work in progress). The table below lists the scores that the HTML5Test site returned for different browsers I have installed on my desktop PC and laptop. A specific list of tests run and features supported are given when you go to the site. Note that I went ahead and tested the IE9 beta and it didn’t do nearly as good as I expected it would, but it’s not officially out yet so I expect that number will change a lot. Am I opposed to HTML5 as a result of these tests? Of course not - I’m actually really excited about what it offers.  However, I’m trying to be realistic and feel it'll definitely add a new level of headache to the Web application development process having been through something like this many years ago. On the flipside, developers that are able to target a specific browser (typically Intranet apps) or master the cross-browser issues are going to release some pretty sweet applications. Check out http://html5gallery.com/ for a look at some of the more cutting-edge sites out there that use HTML5. Also check out the http://www.beautyoftheweb.com site that Microsoft put together to showcase IE9. Chrome 8 Safari 5 for Windows     Opera 10 Firefox 3.6     Internet Explorer 9 Beta (Note that it’s still beta) Internet Explorer 8

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• mysql not starting

  - by Eiriks

  I have a server running on rackspace.com, it been running for about a year (collecting data for a project) and no problems. Now it seems mysql froze (could not connect either through ssh command line, remote app (sequel pro) or web (pages using the db just froze). I got a bit eager to fix this quick and rebooted the virtual server, running ubuntu 10.10. It is a small virtual LAMP server (10gig storage - I'm only using 1, 256mb ram -has not been a problem). Now after the reboot, I cannot get mysql to start again. service mysql status mysql stop/waiting I believe this just means mysql is not running. How do I get this running again? service mysql start start: Job failed to start No. Just typing 'mysql' gives: mysql ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111) There is a .sock file in this folder, 'ls -l' gives: srwxrwxrwx 1 mysql mysql 0 2012-12-01 17:20 mysqld.sock From googleing this for a while now, I see that many talk about the logfile and my.cnf. Logs Not sure witch ones I should look at. This log-file is empty: 'var/log/mysql/error.log', so is the 'var/log/mysql.err' and 'var/log/mysql.log'. my.cnf is located in '/etc/mysql' and looks like this. Can't see anything clearly wrong with it either. # # The MySQL database server configuration file. # # You can copy this to one of: # - "/etc/mysql/my.cnf" to set global options, # - "~/.my.cnf" to set user-specific options. # # One can use all long options that the program supports. # Run program with --help to get a list of available options and with # --print-defaults to see which it would actually understand and use. # # For explanations see # http://dev.mysql.com/doc/mysql/en/server-system-variables.html # This will be passed to all mysql clients # It has been reported that passwords should be enclosed with ticks/quotes # escpecially if they contain "#" chars... # Remember to edit /etc/mysql/debian.cnf when changing the socket location. [client] port = 3306 socket = /var/run/mysqld/mysqld.sock # Here is entries for some specific programs # The following values assume you have at least 32M ram # This was formally known as [safe_mysqld]. Both versions are currently parsed. [mysqld_safe] socket = /var/run/mysqld/mysqld.sock nice = 0 [mysqld] # # * Basic Settings # # # * IMPORTANT # If you make changes to these settings and your system uses apparmor, you may # also need to also adjust /etc/apparmor.d/usr.sbin.mysqld. # user = mysql socket = /var/run/mysqld/mysqld.sock port = 3306 basedir = /usr datadir = /var/lib/mysql tmpdir = /tmp skip-external-locking # # Instead of skip-networking the default is now to listen only on # localhost which is more compatible and is not less secure. bind-address = 127.0.0.1 # # * Fine Tuning # key_buffer = 16M max_allowed_packet = 16M thread_stack = 192K thread_cache_size = 8 # This replaces the startup script and checks MyISAM tables if needed # the first time they are touched myisam-recover = BACKUP #max_connections = 100 #table_cache = 64 #thread_concurrency = 10 # # * Query Cache Configuration # query_cache_limit = 1M query_cache_size = 16M # # * Logging and Replication # # Both location gets rotated by the cronjob. # Be aware that this log type is a performance killer. # As of 5.1 you can enable the log at runtime! #general_log_file = /var/log/mysql/mysql.log #general_log = 1 log_error = /var/log/mysql/error.log # Here you can see queries with especially long duration #log_slow_queries = /var/log/mysql/mysql-slow.log #long_query_time = 2 #log-queries-not-using-indexes # # The following can be used as easy to replay backup logs or for replication. # note: if you are setting up a replication slave, see README.Debian about # other settings you may need to change. #server-id = 1 #log_bin = /var/log/mysql/mysql-bin.log expire_logs_days = 10 max_binlog_size = 100M #binlog_do_db = include_database_name #binlog_ignore_db = include_database_name # # * InnoDB # # InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/. # Read the manual for more InnoDB related options. There are many! # # * Security Features # # Read the manual, too, if you want chroot! # chroot = /var/lib/mysql/ # # For generating SSL certificates I recommend the OpenSSL GUI "tinyca". # # ssl-ca=/etc/mysql/cacert.pem # ssl-cert=/etc/mysql/server-cert.pem # ssl-key=/etc/mysql/server-key.pem [mysqldump] quick quote-names max_allowed_packet = 16M [mysql] #no-auto-rehash # faster start of mysql but no tab completition [isamchk] key_buffer = 16M # # * IMPORTANT: Additional settings that can override those from this file! # The files must end with '.cnf', otherwise they'll be ignored. # !includedir /etc/mysql/conf.d/ I need the data in the database (so i'd like to avoid reinstalling), and I need it back up running again. All hint, tips and solutions are welcomed and appreciated.

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• Parallelism in .NET – Part 1, Decomposition

  - by Reed

  The first step in designing any parallelized system is Decomposition.  Decomposition is nothing more than taking a problem space and breaking it into discrete parts.  When we want to work in parallel, we need to have at least two separate things that we are trying to run.  We do this by taking our problem and decomposing it into parts. There are two common abstractions that are useful when discussing parallel decomposition: Data Decomposition and Task Decomposition.  These two abstractions allow us to think about our problem in a way that helps leads us to correct decision making in terms of the algorithms we’ll use to parallelize our routine. To start, I will make a couple of minor points. I’d like to stress that Decomposition has nothing to do with specific algorithms or techniques.  It’s about how you approach and think about the problem, not how you solve the problem using a specific tool, technique, or library.  Decomposing the problem is about constructing the appropriate mental model: once this is done, you can choose the appropriate design and tools, which is a subject for future posts. Decomposition, being unrelated to tools or specific techniques, is not specific to .NET in any way.  This should be the first step to parallelizing a problem, and is valid using any framework, language, or toolset.  However, this gives us a starting point – without a proper understanding of decomposition, it is difficult to understand the proper usage of specific classes and tools within the .NET framework. Data Decomposition is often the simpler abstraction to use when trying to parallelize a routine.  In order to decompose our problem domain by data, we take our entire set of data and break it into smaller, discrete portions, or chunks.  We then work on each chunk in the data set in parallel. This is particularly useful if we can process each element of data independently of the rest of the data.  In a situation like this, there are some wonderfully simple techniques we can use to take advantage of our data.  By decomposing our domain by data, we can very simply parallelize our routines.  In general, we, as developers, should be always searching for data that can be decomposed. Finding data to decompose if fairly simple, in many instances.  Data decomposition is typically used with collections of data.  Any time you have a collection of items, and you’re going to perform work on or with each of the items, you potentially have a situation where parallelism can be exploited.  This is fairly easy to do in practice: look for iteration statements in your code, such as for and foreach. Granted, every for loop is not a candidate to be parallelized.  If the collection is being modified as it’s iterated, or the processing of elements depends on other elements, the iteration block may need to be processed in serial.  However, if this is not the case, data decomposition may be possible. Let’s look at one example of how we might use data decomposition.  Suppose we were working with an image, and we were applying a simple contrast stretching filter.  When we go to apply the filter, once we know the minimum and maximum values, we can apply this to each pixel independently of the other pixels.  This means that we can easily decompose this problem based off data – we will do the same operation, in parallel, on individual chunks of data (each pixel). Task Decomposition, on the other hand, is focused on the individual tasks that need to be performed instead of focusing on the data.  In order to decompose our problem domain by tasks, we need to think about our algorithm in terms of discrete operations, or tasks, which can then later be parallelized. Task decomposition, in practice, can be a bit more tricky than data decomposition.  Here, we need to look at what our algorithm actually does, and how it performs its actions.  Once we have all of the basic steps taken into account, we can try to analyze them and determine whether there are any constraints in terms of shared data or ordering.  There are no simple things to look for in terms of finding tasks we can decompose for parallelism; every algorithm is unique in terms of its tasks, so every algorithm will have unique opportunities for task decomposition. For example, say we want our software to perform some customized actions on startup, prior to showing our main screen.  Perhaps we want to check for proper licensing, notify the user if the license is not valid, and also check for updates to the program.  Once we verify the license, and that there are no updates, we’ll start normally.  In this case, we can decompose this problem into tasks – we have a few tasks, but there are at least two discrete, independent tasks (check licensing, check for updates) which we can perform in parallel.  Once those are completed, we will continue on with our other tasks. One final note – Data Decomposition and Task Decomposition are not mutually exclusive.  Often, you’ll mix the two approaches while trying to parallelize a single routine.  It’s possible to decompose your problem based off data, then further decompose the processing of each element of data based on tasks.  This just provides a framework for thinking about our algorithms, and for discussing the problem.

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• Creating packages in code – Execute SQL Task

  The Execute SQL Task is for obvious reasons very well used, so I thought if you are building packages in code the chances are you will be using it. Using the task basic features of the task are quite straightforward, add the task and set some properties, just like any other. When you start interacting with variables though it can be a little harder to grasp so these samples should see you through. Some of these more advanced features are explained in much more detail in our ever popular post The Execute SQL Task, here I’ll just be showing you how to implement them in code. The abbreviated code blocks below demonstrate the different features of the task. The complete code has been encapsulated into a sample class which you can download (ExecSqlPackage.cs). Each feature described has its own method in the sample class which is mentioned after the code block. This first sample just shows adding the task, setting the basic properties for a connection and of course an SQL statement. Package package = new Package(); // Add the SQL OLE-DB connection ConnectionManager sqlConnection = AddSqlConnection(package, "localhost", "master"); // Add the SQL Task package.Executables.Add("STOCK:SQLTask"); // Get the task host wrapper TaskHost taskHost = package.Executables[0] as TaskHost; // Set required properties taskHost.Properties["Connection"].SetValue(taskHost, sqlConnection.ID); taskHost.Properties["SqlStatementSource"].SetValue(taskHost, "SELECT * FROM sysobjects"); For the full version of this code, see the CreatePackage method in the sample class. The AddSqlConnection method is a helper method that adds an OLE-DB connection to the package, it is of course in the sample class file too. Returning a single value with a Result Set The following sample takes a different approach, getting a reference to the ExecuteSQLTask object task itself, rather than just using the non-specific TaskHost as above. Whilst it means we need to add an extra reference to our project (Microsoft.SqlServer.SQLTask) it makes coding much easier as we have compile time validation of any property and types we use. For the more complex properties that is very valuable and saves a lot of time during development. The query has also been changed to return a single value, one row and one column. The sample shows how we can return that value into a variable, which we also add to our package in the code. To do this manually you would set the Result Set property on the General page to Single Row and map the variable on the Result Set page in the editor. Package package = new Package(); // Add the SQL OLE-DB connection ConnectionManager sqlConnection = AddSqlConnection(package, "localhost", "master"); // Add the SQL Task package.Executables.Add("STOCK:SQLTask"); // Get the task host wrapper TaskHost taskHost = package.Executables[0] as TaskHost; // Add variable to hold result value package.Variables.Add("Variable", false, "User", 0); // Get the task object ExecuteSQLTask task = taskHost.InnerObject as ExecuteSQLTask; // Set core properties task.Connection = sqlConnection.Name; task.SqlStatementSource = "SELECT id FROM sysobjects WHERE name = 'sysrowsets'"; // Set single row result set task.ResultSetType = ResultSetType.ResultSetType_SingleRow; // Add result set binding, map the id column to variable task.ResultSetBindings.Add(); IDTSResultBinding resultBinding = task.ResultSetBindings.GetBinding(0); resultBinding.ResultName = "id"; resultBinding.DtsVariableName = "User::Variable"; For the full version of this code, see the CreatePackageResultVariable method in the sample class. The other types of Result Set behaviour are just a variation on this theme, set the property and map the result binding as required. Parameter Mapping for SQL Statements This final example uses a parameterised SQL statement, with the coming from a variable. The syntax varies slightly between connection types, as explained in the Working with Parameters and Return Codes in the Execute SQL Taskhelp topic, but OLE-DB is the most commonly used, for which a question mark is the parameter value placeholder. Package package = new Package(); // Add the SQL OLE-DB connection ConnectionManager sqlConnection = AddSqlConnection(package, ".", "master"); // Add the SQL Task package.Executables.Add("STOCK:SQLTask"); // Get the task host wrapper TaskHost taskHost = package.Executables[0] as TaskHost; // Get the task object ExecuteSQLTask task = taskHost.InnerObject as ExecuteSQLTask; // Set core properties task.Connection = sqlConnection.Name; task.SqlStatementSource = "SELECT id FROM sysobjects WHERE name = ?"; // Add variable to hold parameter value package.Variables.Add("Variable", false, "User", "sysrowsets"); // Add input parameter binding task.ParameterBindings.Add(); IDTSParameterBinding parameterBinding = task.ParameterBindings.GetBinding(0); parameterBinding.DtsVariableName = "User::Variable"; parameterBinding.ParameterDirection = ParameterDirections.Input; parameterBinding.DataType = (int)OleDBDataTypes.VARCHAR; parameterBinding.ParameterName = "0"; parameterBinding.ParameterSize = 255; For the full version of this code, see the CreatePackageParameterVariable method in the sample class. You’ll notice the data type has to be specified for the parameter IDTSParameterBinding .DataType Property, and these type codes are connection specific too. My enumeration I wrote several years ago is shown below was probably done by reverse engineering a package and also the API header file, but I recently found a very handy post that covers more connections as well for exactly this, Setting the DataType of IDTSParameterBinding objects (Execute SQL Task). /// <summary> /// Enumeration of OLE-DB types, used when mapping OLE-DB parameters. /// </summary> private enum OleDBDataTypes { BYTE = 0x11, CURRENCY = 6, DATE = 7, DB_VARNUMERIC = 0x8b, DBDATE = 0x85, DBTIME = 0x86, DBTIMESTAMP = 0x87, DECIMAL = 14, DOUBLE = 5, FILETIME = 0x40, FLOAT = 4, GUID = 0x48, LARGE_INTEGER = 20, LONG = 3, NULL = 1, NUMERIC = 0x83, NVARCHAR = 130, SHORT = 2, SIGNEDCHAR = 0x10, ULARGE_INTEGER = 0x15, ULONG = 0x13, USHORT = 0x12, VARCHAR = 0x81, VARIANT_BOOL = 11 } Download Sample code ExecSqlPackage.cs (10KB)

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• The ASP.NET Daily Community Spotlight - How posts get there, and how to make it your Visual Studio Start Page

  - by Jon Galloway

  One really cool part of my job is selecting the articles for the Daily Community Spotlight, on the home page of the ASP.NET website. The spotlight highlights a new post about ASP.NET development every day from a member of the ASP.NET community. You can find it on the home page of the ASP.NET site, at http://asp.net These posts aren't automatically drawn from a pool of RSS feeds or anything - I pick a new post for each day of the year. How I pick the posts I have a few important selection criteria: Interesting to well rounded ASP.NET developers The ASP.NET website has a lot of material for all skill and experience levels, from download / get started to advanced. I try to select community spotlight posts to round that out with fresh and timely information that working ASP.NET developers can really use. Posts highlight solutions to common problems, clever projects and code that helps you leverage ASP.NET, and important announcements about things you can use today. As part of that, I try to mix between ASP.NET MVC, Web Forms, and Web Pages (a.k.a. WebMatrix). As a professional developer, I want to keep on top of all of my options for ASP.NET development, and the common platform base they all share generally means that good ASP.NET code is good ASP.NET code. Exposing new and non-Microsoft community members as much as possible The exercise of selecting good ASP.NET community posts every day of the year has made me think about what the community is. Given the choice, I'll always favor non-Microsoft employees, but since Microsoft often hires ASP.NET community members and MVP's (myself included), I really think that the ASP.NET community includes developers who are using and writing about ASP.NET, both inside and outside of Microsoft. I'm especially excited about the opportunity to highlight new and lesser known bloggers. Usually being featured on the ASP.NET Community Spotlight gives a pretty good traffic bump, and I love being able to both provide great content to the community and encourage lesser known community members by giving them some (much deserved) attention. Announcements only when they're useful to working developers - not marketing Some of the posts are announcements about new releases, such as Scott Hanselman's post on ASP.NET Universal Providers for Session, Memebership, and Roles. I include those when I think they're interesting and of immediate use to you on projects. I occasionally get asked to link to new content from a team at Microsoft; if it's useful and timely content I'll ask them to point me to a blog post by an actual person rather than a faceless team. How the posts are managed This feed used to be managed by an internal spreadsheet on a Sharepoint site, which was painful for a lot of reasons. I took a cue from Jon Udell, who uses of a public Delicious feed feed for his Elm City project, and we moved the management of these posts over to a Delicious feed as well. You can hear more about Jon's use of Delicious in Elm City in our Herding Code interview - still one of my favorite interviews. We ended up with a simpler scenario, but Note: I watched the Yahoo/Delicious news over the past year and was happy to see that Delicious was recently acquired by the founders of YouTube. I investigated several other Delicious competitors, but am happy with Delicious for now. My Delicious feed here: http://www.delicious.com/jon_galloway You can also browse through this past year's ASP.NET Community Spotlight posts using the (pretty cool) Delicious Browse Bar Submitting articles I'm always on the lookout for new articles to feature. The best way to get them to me is to share them via Delicious. It's pretty easy - sign up for an account, then you can add a post and share it to me. Alternatively, you can send them to me via Twitter (@jongalloway) or e-mail (). If you do e-mail me, it helps to include a short description and your full name so I can credit you. Way too many developer blogs don't include names and pictures; if I can't find them I can't feature the post. Subscribing to the Community Spotlight feed The Community Spotlight is available as an RSS feed, so you might want to subscribe to it: http://www.asp.net/rss/spotlight Setting the ASP.NET Community Spotlight feed as your Visual Studio start page If you're an ASP.NET developer, you might consider setting the ASP.NET Community Spotlight as the content for your Visual Studio Start Page. It's really easy - here's how to do it in Visual Studio 2010: Display the Visual Studio Start Page if it's not already showing (View / Start Page) Click on the Latest News tab and enter the following RSS URL: http://www.asp.net/rss/spotlight If you didn't previously have RSS feeds enabled for your start page, click the Enable RSS Feed button Now, every time you start up Visual Studio you'll see great content from members of the ASP.NET community: You can also configure - and disable, if you'd like - the Visual Studio start page in the Tools / Options / Environment / Startup dialog. Credits I'll do a follow-up highlighting some places I commonly find great content for the feed, but I'd like to specifically point out two of them: Elijah Manor posts a lot of great content, which is available in his Twitter feed at @elijahmanor, on his Delicious feed, and on a dedicated website - Web Dev Tweets Chris Alcock's The Morning Brew is a must-read blog which highlights each day's best blog posts across the .NET community. He's an absolute machine, and no matter how obscure the post I find, I can guarantee he'll find it as well if he hasn't already. Did I say must read?

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• 8 Backup Tools Explained for Windows 7 and 8

  - by Chris Hoffman

  Backups on Windows can be confusing. Whether you’re using Windows 7 or 8, you have quite a few integrated backup tools to think about. Windows 8 made quite a few changes, too. You can also use third-party backup software, whether you want to back up to an external drive or back up your files to online storage. We won’t cover third-party tools here — just the ones built into Windows. Backup and Restore on Windows 7 Windows 7 has its own Backup and Restore feature that lets you create backups manually or on a schedule. You’ll find it under Backup and Restore in the Control Panel. The original version of Windows 8 still contained this tool, and named it Windows 7 File Recovery. This allowed former Windows 7 users to restore files from those old Windows 7 backups or keep using the familiar backup tool for a little while. Windows 7 File Recovery was removed in Windows 8.1. System Restore System Restore on both Windows 7 and 8 functions as a sort of automatic system backup feature. It creates backup copies of important system and program files on a schedule or when you perform certain tasks, such as installing a hardware driver. If system files become corrupted or your computer’s software becomes unstable, you can use System Restore to restore your system and program files from a System Restore point. This isn’t a way to back up your personal files. It’s more of a troubleshooting feature that uses backups to restore your system to its previous working state. Previous Versions on Windows 7 Windows 7′s Previous Versions feature allows you to restore older versions of files — or deleted files. These files can come from backups created with Windows 7′s Backup and Restore feature, but they can also come from System Restore points. When Windows 7 creates a System Restore point, it will sometimes contain your personal files. Previous Versions allows you to extract these personal files from restore points. This only applies to Windows 7. On Windows 8, System Restore won’t create backup copies of your personal files. The Previous Versions feature was removed on Windows 8. File History Windows 8 replaced Windows 7′s backup tools with File History, although this feature isn’t enabled by default. File History is designed to be a simple, easy way to create backups of your data files on an external drive or network location. File History replaces both Windows 7′s Backup and Previous Versions features. Windows System Restore won’t create copies of personal files on Windows 8. This means you can’t actually recover older versions of files until you enable File History yourself — it isn’t enabled by default. System Image Backups Windows also allows you to create system image backups. These are backup images of your entire operating system, including your system files, installed programs, and personal files. This feature was included in both Windows 7 and Windows 8, but it was hidden in the preview versions of Windows 8.1. After many user complaints, it was restored and is still available in the final version of Windows 8.1 — click System Image Backup on the File History Control Panel. Storage Space Mirroring Windows 8′s Storage Spaces feature allows you to set up RAID-like features in software. For example, you can use Storage Space to set up two hard disks of the same size in a mirroring configuration. They’ll appear as a single drive in Windows. When you write to this virtual drive, the files will be saved to both physical drives. If one drive fails, your files will still be available on the other drive. This isn’t a good long-term backup solution, but it is a way of ensuring you won’t lose important files if a single drive fails. Microsoft Account Settings Backup Windows 8 and 8.1 allow you to back up a variety of system settings — including personalization, desktop, and input settings. If you’re signing in with a Microsoft account, OneDrive settings backup is enabled automatically. This feature can be controlled under OneDrive > Sync settings in the PC settings app. This feature only backs up a few settings. It’s really more of a way to sync settings between devices. OneDrive Cloud Storage Microsoft hasn’t been talking much about File History since Windows 8 was released. That’s because they want people to use OneDrive instead. OneDrive — formerly known as SkyDrive — was added to the Windows desktop in Windows 8.1. Save your files here and they’ll be stored online tied to your Microsoft account. You can then sign in on any other computer, smartphone, tablet, or even via the web and access your files. Microsoft wants typical PC users “backing up” their files with OneDrive so they’ll be available on any device. You don’t have to worry about all these features. Just choose a backup strategy to ensure your files are safe if your computer’s hard disk fails you. Whether it’s an integrated backup tool or a third-party backup application, be sure to back up your files.

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• Entity Framework 4.0: Creating objects of correct type when using lazy loading

  - by DigiMortal

  In my posting about Entity Framework 4.0 and POCOs I introduced lazy loading in EF applications. EF uses proxy classes for lazy loading and this means we have new types in that come and go dynamically in runtime. We don’t have these types available when we write code but we cannot forget that EF may expect us to use dynamically generated types. In this posting I will give you simple hint how to use correct types in your code. The background of lazy loading and proxy classes As a first thing I will explain you in short what is proxy class. Business classes when designed correctly have no knowledge about their birth and death – they don’t know how they are created and they don’t know how their data is persisted. This is the responsibility of object runtime. When we use lazy loading we need a little bit different classes that know how to load data for properties when code accesses the property first time. As we cannot add this functionality to our business classes (they may be stored through more than one data access technology or by more than one Data Access Layer (DAL)) we create proxy classes that extend our business classes. If we have class called Product and product has lazy loaded property called Customer then we need proxy class, let’s say ProductProxy, that has same public signature as Product so we can use it INSTEAD OF product in our code. ProductProxy overrides Customer property. If customer is not asked then customer is null. But if we ask for Customer property then overridden property of ProductProxy loads it from database. This is how lazy loading works. Problem – two types for same thing As lazy loading may introduce dynamically generated proxy types we don’t know in our application code which type is returned. We cannot be sure that we have Product not ProductProxy returned. This leads us to the following question: how can we create Product of correct type if we don’t know the correct type? In EF solution is simple. Solution – use factory methods If you are using repositories and you are not using factories (imho it is pretty pointless with mapper) you can add factory methods to your EF based repositories. Take a look at this class. public class Event {     public int ID { get; set; }     public string Title { get; set; }     public string Location { get; set; }     public virtual Party Organizer { get; set; }     public DateTime Date { get; set; } } We have virtual member called Organizer. This property is virtual because we want to use lazy loading on this class so Organizer is loaded only when we ask it. EF provides us with method called CreateObject<T>(). CreateObject<T>() is member of ObjectContext class and it creates the object based on given type. In runtime proxy type for Event is created for us automatically and when we call CreateObject<T>() for Event it returns as object of Event proxy type. The factory method for events repository is as follows. public Event CreateEvent() {     var evt = _context.CreateObject<Event>();     return evt; } And we are done. Instead of creating factory classes we created factory methods that guarantee that created objects are of correct type. Conclusion Although lazy loading introduces some new objects we cannot use at design time because they live only in runtime we can write code without worrying about exact implementation type of object. This holds true until we have clean code and we don’t make any decisions based on object type. EF4.0 provides us with very simple factory method that create and return objects of correct type. All we had to do was adding factory methods to our repositories.

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• Kaiden and the Arachnoid Cyst

  - by Martin Hinshelwood

  Some of you may remember when my son Kaiden was born I posted pictures of him and his sister. Kaiden is now 15 months old and is progressing perfectly in every area except that and we had been worried that he was not walking yet. We were only really concerned as his sister was walking at 8 months. Figure: Kai as his usual self   Jadie and I were concerned over that and that he had a rather large head (noggin) so we talked to various GP’s and our health visitor who immediately dismissed our concerns every time. That was until about two months ago when we happened to get a GP whose daughter had Hyper Mobility and she recognised the symptoms immediately. We were referred to the Southbank clinic who were lovely and the paediatrician confirmed that he had Hyper Mobility after testing all of his faculties. This just means that his joints are overly mobile and would need a little physiotherapy to help him out. At the end the paediatrician remarked offhand that he has a rather large head and wanted to measure it. Sure enough he was a good margin above the highest percentile mark for his height and weight. The paediatrician showed the measurements to a paediatric consultant who, as a precautionary measure, referred us for an MRI at Yorkhill Children's hospital. Now, Yorkhill has always been fantastic to us, and this was no exception. You know we have NEVER had a correct diagnosis for the kids (with the exception of the above) from a GP and indeed twice have been proscribed incorrect medication that made the kids sicker! We now always go strait to Yorkhill to save them having to fix GP mistakes as well. Monday 24th May, 7pm The scan went fantastically, with Kaiden sleeping in the MRI machine for all but 5 minutes at the end where he waited patiently for it to finish. We were not expecting anything to be wrong as this was just a precautionary scan to make sure that nothing in his head was affecting his gross motor skills. After the scan we were told to expect a call towards the end of the week… Tuesday 25th May, 12pm The very next day we got a call from Southbank who said that they has found an Arachnoid Cyst and could we come in the next day to see a Consultant and that Kai would need an operation. Wednesday 26th May, 12:30pm We went into the Southbank clinic and spoke to the paediatric consultant who assured us that it was operable but that it was taking up considerable space in Kai’s head. Cerebrospinal fluid is building up as a cyst is blocking the channels it uses to drain. Thankfully they told us that prospects were good and that Kai would expect to make a full recovery before showing us the MRI pictures. Figure: Normal brain MRI cross section. This normal scan shows the spaces in the middle of the brain that contain and produce the Cerebrospinal fluid. Figure: Normal Cerebrospinal Flow This fluid is needed by the brain but is drained in the middle down the spinal column. Figure: Kai’s cyst blocking the four channels. I do not think that I need to explain the difference between the healthy picture and Kai’s picture. However you can see in this first picture the faint outline of the cyst in the middle that is blocking the four channels from draining. After seeing the scans a Neurosurgeon has decided that he is not acute, but needs an operation to unblock the flow. Figure: OMFG! You can see in the second picture the effect of the build up of fluid. If I was not horrified by the first picture I was seriously horrified by this one. What next? Kai is not presenting the symptoms of vomiting or listlessness that would show an immediate problem and as such we will get an appointment to see the Paediatric Neurosurgeon at the Southern General hospital in about 4 weeks. This timescale is based on the Neurosurgeon seeing the scans. After that Kai will need an operation to release the pressure and either remove the cyst completely or put in a permanent shunt (tube from brain to stomach) to bypass the blockage. We have updated his notes for the referral with additional recent information on top of the scan that the consultant things will help improve the timescales, but that is just a guess.   All we can do now is wait and see, and be watchful for tell tail signs of listlessness, eye problems and vomiting that would signify a worsening of his condition.   Technorati Tags: Personal

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• Seriously, It’s Time to Get Your Content Act Together

  - by Mike Stiles

  Branded content, content marketing, social content, brand journalism, we’re seeing those terms more and more. Why? The technology tools are coming together. We should know. We can gather big data, crunch it, listen to the public, moderate, respond, get to know the customer intimately, know what they like, know what they want, we can target, distribute, amplify, measure engagement and reaction, modify strategy and even automate a great deal of all that. An amazing machine, a sleek, smooth-running engine has been built such that all the parts can interact and work together to deliver peak performance and maximum output. But that engine isn’t going anywhere without any gas. Content is the gas. Yes, we curate other people’s content. We can siphon their gas. There’s tech to help with that too. But as for the creation of original, worthwhile content made for a specific audience, our audience, machines can’t do that…at least not yet. Curated content is great. But somebody has to originate the content for it to be curated and shared. And since the need for good, curated content is obviously large and the desire to share is there, it’s a winning proposition for a brand to be a consistent producer of original content. And yet, it feels like content is an issue we’re avoiding. There’s a reluctance to build a massive pipeline if you have no idea what you’re going to run through it. The C-suite often doesn’t know what content is, that it’s different from ads, where to get it, who makes it, how long it should be, what the point of it is if there’s no hard sell of the product, what it costs, how to use it, how to measure it, how to make sure it’s good, or how to make sure it will keep flowing. It could be the reason many brands aren’t pulling the trigger on socially enabling the enterprise. And that’s a shame, because there are a lot of creative, daring, experimental, uniquely talented entertainers and journalists chomping at the bit to execute content for brands. But for many corporate executives, content is “weird,” and the people who make it are even weirder. The content side of the equation is human. It’s art, but art that can be informed by data. The natural inclination is for brands to turn to their agencies for such creative endeavors. But agencies are falling into one of two categories. They’re failing to transition from ads to content. In “Content Era, What’s the Role of Agencies?” Alexander Jutkowitz says agencies were made for one-hit campaigns, not ongoing content. Or, they’re ready and capable but can’t get clients to do the right things. Agencies have to make money, even if it means continuing to do the wrong things because that’s all the client will agree to. So what we wind up with in the pipeline is advertising, marketing-heavy content, content that was obviously created or spearheaded by non-creative executives, random & inconsistent content, copy written for SEO bots, and other completely uninteresting nightmares. Frank Rose, author of “The Art of Immersion,” writes, “Content without story and excitement is noise pollution.” In the old days, you made an ad and inserted it into shows made by people who knew what they were doing. You could bask in that show’s success and leverage their audience. Now, you are tasked with attracting, amassing and holding your own audience. You may just want to make, advertise and sell your widgets. But now there’s a war on for a precious commodity, attention. People are busy. They have filters to keep uninteresting and irrelevant things out. They value their time and expect value back when they give it up. Joe Pulizzi, founder of the Content Marketing Institute, says, "Your customers don't care about you, your products, your services…they care about themselves, their wants and their needs." Is it worth getting serious about content and doing it right? 61% of consumers feel better about a company that delivers custom content (Custom Content Council). Interesting content is one of the top 3 reasons people follow brands on social (Content+). 78% of consumers think organizations that provide custom content want to build good relationships with them (TMG Custom Media). On the B2B side, 80% of business decision makers prefer to get company info in a series of articles vs. an ad. So what’s the hang-up? Cited barriers to content marketing are lack of human resources (42%) and lack of budget (35%). 54% of brands don’t have a single on-site, dedicated content creator. And only 38% of brands have a content marketing strategy. Tech has built the biggest, most incredible stage for brands that’s ever been built. Putting something on that stage is your responsibility. Do a bad show, or no show at all, and you’ll be the beautiful, talented actress that never got discovered. @mikestilesPhoto: Gabriella Fabbri, stock.xchng

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