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  • WebLogic Server Performance and Tuning: Part I - Tuning JVM

    - by Gokhan Gungor
    Each WebLogic Server instance runs in its own dedicated Java Virtual Machine (JVM) which is their runtime environment. Every Admin Server in any domain executes within a JVM. The same also applies for Managed Servers. WebLogic Server can be used for a wide variety of applications and services which uses the same runtime environment and resources. Oracle WebLogic ships with 2 different JVM, HotSpot and JRocket but you can choose which JVM you want to use. JVM is designed to optimize itself however it also provides some startup options to make small changes. There are default values for its memory and garbage collection. In real world, you will not want to stick with the default values provided by the JVM rather want to customize these values based on your applications which can produce large gains in performance by making small changes with the JVM parameters. We can tell the garbage collector how to delete garbage and we can also tell JVM how much space to allocate for each generation (of java Objects) or for heap. Remember during the garbage collection no other process is executed within the JVM or runtime, which is called STOP THE WORLD which can affect the overall throughput. Each JVM has its own memory segment called Heap Memory which is the storage for java Objects. These objects can be grouped based on their age like young generation (recently created objects) or old generation (surviving objects that have lived to some extent), etc. A java object is considered garbage when it can no longer be reached from anywhere in the running program. Each generation has its own memory segment within the heap. When this segment gets full, garbage collector deletes all the objects that are marked as garbage to create space. When the old generation space gets full, the JVM performs a major collection to remove the unused objects and reclaim their space. A major garbage collect takes a significant amount of time and can affect system performance. When we create a managed server either on the same machine or on remote machine it gets its initial startup parameters from $DOMAIN_HOME/bin/setDomainEnv.sh/cmd file. By default two parameters are set:     Xms: The initial heapsize     Xmx: The max heapsize Try to set equal initial and max heapsize. The startup time can be a little longer but for long running applications it will provide a better performance. When we set -Xms512m -Xmx1024m, the physical heap size will be 512m. This means that there are pages of memory (in the state of the 512m) that the JVM does not explicitly control. It will be controlled by OS which could be reserve for the other tasks. In this case, it is an advantage if the JVM claims the entire memory at once and try not to spend time to extend when more memory is needed. Also you can use -XX:MaxPermSize (Maximum size of the permanent generation) option for Sun JVM. You should adjust the size accordingly if your application dynamically load and unload a lot of classes in order to optimize the performance. You can set the JVM options/heap size from the following places:     Through the Admin console, in the Server start tab     In the startManagedWeblogic script for the managed servers     $DOMAIN_HOME/bin/startManagedWebLogic.sh/cmd     JAVA_OPTIONS="-Xms1024m -Xmx1024m" ${JAVA_OPTIONS}     In the setDomainEnv script for the managed servers and admin server (domain wide)     USER_MEM_ARGS="-Xms1024m -Xmx1024m" When there is free memory available in the heap but it is too fragmented and not contiguously located to store the object or when there is actually insufficient memory we can get java.lang.OutOfMemoryError. We should create Thread Dump and analyze if that is possible in case of such error. The second option we can use to produce higher throughput is to garbage collection. We can roughly divide GC algorithms into 2 categories: parallel and concurrent. Parallel GC stops the execution of all the application and performs the full GC, this generally provides better throughput but also high latency using all the CPU resources during GC. Concurrent GC on the other hand, produces low latency but also low throughput since it performs GC while application executes. The JRockit JVM provides some useful command-line parameters that to control of its GC scheme like -XgcPrio command-line parameter which takes the following options; XgcPrio:pausetime (To minimize latency, parallel GC) XgcPrio:throughput (To minimize throughput, concurrent GC ) XgcPrio:deterministic (To guarantee maximum pause time, for real time systems) Sun JVM has similar parameters (like  -XX:UseParallelGC or -XX:+UseConcMarkSweepGC) to control its GC scheme. We can add -verbosegc -XX:+PrintGCDetails to monitor indications of a problem with garbage collection. Try configuring JVM’s of all managed servers to execute in -server mode to ensure that it is optimized for a server-side production environment.

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  • JMX Based Monitoring - Part Three - Web App Server Monitoring

    - by Anthony Shorten
    In the last blog entry I showed a technique for integrating a JMX console with Oracle WebLogic which is a standard feature of Oracle WebLogic 11g. Customers on other Web Application servers and other versions of Oracle WebLogic can refer to the documentation provided with the server to do a similar thing. In this blog entry I am going to discuss a new feature that is only present in Oracle Utilities Application Framework 4 and above that allows JMX to be used for management and monitoring the Oracle Utilities Web Applications. In this case JMX can be used to perform monitoring as well as provide the management of the cache. In Oracle Utilities Application Framework you can enable Web Application Server JMX monitoring that is unique to the framework by specifying a JMX port number in RMI Port number for JMX Web setting and initial credentials in the JMX Enablement System User ID and JMX Enablement System Password configuration options. These options are available using the configureEnv[.sh] -a utility. Once this is information is supplied a number of configuration files are built (by the initialSetup[.sh] utility) to configure the facility: spl.properties - contains the JMX URL, the security configuration and the mbeans that are enabled. For example, on my demonstration machine: spl.runtime.management.rmi.port=6740 spl.runtime.management.connector.url.default=service:jmx:rmi:///jndi/rmi://localhost:6740/oracle/ouaf/webAppConnector jmx.remote.x.password.file=scripts/ouaf.jmx.password.file jmx.remote.x.access.file=scripts/ouaf.jmx.access.file ouaf.jmx.com.splwg.base.support.management.mbean.JVMInfo=enabled ouaf.jmx.com.splwg.base.web.mbeans.FlushBean=enabled ouaf.jmx.* files - contain the userid and password. The default setup uses the JMX default security configuration. You can use additional security features by altering the spl.properties file manually or using a custom template. For more security options see the JMX Site. Once it has been configured and the changes reflected in the product using the initialSetup[.sh] utility the JMX facility can be used. For illustrative purposes, I will use jconsole but any JSR160 complaint browser or client can be used (with the appropriate configuration). Once you start jconsole (ensure that splenviron[.sh] is executed prior to execution to set the environment variables or for remote connection, ensure java is in your path and jconsole.jar in your classpath) you specify the URL in the spl.management.connnector.url.default entry and the credentials you specified in the jmx.remote.x.* files. Remember these are encrypted by default so if you try and view the file you may be able to decipher it visually. For example: There are three Mbeans available to you: flushBean - This is a JMX replacement for the jsp versions of the flush utilities provided in previous releases of the Oracle Utilities Application Framework. You can manage the cache using the provided operations from JMX. The jsp versions of the flush utilities are still provided, for backward compatibility, but now are authorization controlled. JVMInfo - This is a JMX replacement for the jsp version of the JVMInfo screen used by support to get a handle on JVM information. This information is environmental not operational and is used for support purposes. The jsp versions of the JVMInfo utilities are still provided, for backward compatibility, but now is also authorization controlled. JVMSystem - This is an implementation of the Java system MXBeans for use in monitoring. We provide our own implementation of the base Mbeans to save on creating another JMX configuration for internal monitoring and to provide a consistent interface across platforms for the MXBeans. This Mbean is disabled by default and can be enabled using the enableJVMSystemBeans operation. This Mbean allows for the monitoring of the ClassLoading, Memory, OperatingSystem, Runtime and the Thread MX beans. Refer to the Server Administration Guides provided with your product and the Technical Best Practices Whitepaper for information about individual statistics. The Web Application Server JMX monitoring allows greater visibility for monitoring and management of the Oracle Utilities Application Framework application from jconsole or any JSR160 compliant JMX browser or JMX console.

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  • Sorting a ListView in WPF – Part II

    - by marianor
    Some time ago I wrote a post about how to sort a ListView by clicking on the header of the column. The problem with that solution was that you needed to implement it each time and you have to define an explicit header for each column. As a more general solution I use attached properties to extend the ListView and GridViewColumn . The first attached property is tied to the ListView itself, and it indicates that the control supports sorting. This property attach or detach to the Click event of the...(read more)

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  • Parallelism in .NET – Part 19, TaskContinuationOptions

    - by Reed
    My introduction to Task continuations demonstrates continuations on the Task class.  In addition, I’ve shown how continuations allow handling of multiple tasks in a clean, concise manner.  Continuations can also be used to handle exceptional situations using a clean, simple syntax. In addition to standard Task continuations , the Task class provides some options for filtering continuations automatically.  This is handled via the TaskContinationOptions enumeration, which provides hints to the TaskScheduler that it should only continue based on the operation of the antecedent task. This is especially useful when dealing with exceptions.  For example, we can extend the sample from our earlier continuation discussion to include support for handling exceptions thrown by the Factorize method: // Get a copy of the UI-thread task scheduler up front to use later var uiScheduler = TaskScheduler.FromCurrentSynchronizationContext(); // Start our task var factorize = Task.Factory.StartNew( () => { int primeFactor1 = 0; int primeFactor2 = 0; bool result = Factorize(10298312, ref primeFactor1, ref primeFactor2); return new { Result = result, Factor1 = primeFactor1, Factor2 = primeFactor2 }; }); // When we succeed, report the results to the UI factorize.ContinueWith(task => textBox1.Text = string.Format("{0}/{1} [Succeeded {2}]", task.Result.Factor1, task.Result.Factor2, task.Result.Result), CancellationToken.None, TaskContinuationOptions.NotOnFaulted, uiScheduler); // When we have an exception, report it factorize.ContinueWith(task => textBox1.Text = string.Format("Error: {0}", task.Exception.Message), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, uiScheduler); .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; } The above code works by using a combination of features.  First, we schedule our task, the same way as in the previous example.  However, in this case, we use a different overload of Task.ContinueWith which allows us to specify both a specific TaskScheduler (in order to have your continuation run on the UI’s synchronization context) as well as a TaskContinuationOption.  In the first continuation, we tell the continuation that we only want it to run when there was not an exception by specifying TaskContinuationOptions.NotOnFaulted.  When our factorize task completes successfully, this continuation will automatically run on the UI thread, and provide the appropriate feedback. However, if the factorize task has an exception – for example, if the Factorize method throws an exception due to an improper input value, the second continuation will run.  This occurs due to the specification of TaskContinuationOptions.OnlyOnFaulted in the options.  In this case, we’ll report the error received to the user. We can use TaskContinuationOptions to filter our continuations by whether or not an exception occurred and whether or not a task was cancelled.  This allows us to handle many situations, and is especially useful when trying to maintain a valid application state without ever blocking the user interface.  The same concepts can be extended even further, and allow you to chain together many tasks based on the success of the previous ones.  Continuations can even be used to create a state machine with full error handling, all without blocking the user interface thread.

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  • JMX Based Monitoring - Part Two - JVM Monitoring

    - by Anthony Shorten
    This the second article in the series focussing on the JMX based monitoring capabilities possible with the Oracle Utilities Application Framework. In all versions of the Oracle utilities Application Framework, it is possible to use the basic JMX based monitoring available with the Java Virtual Machine to provide basic statistics ablut the JVM. In Java 5 and above, the JVM automatically allowed local monitoring of the JVM statistics from an approporiate console. When I say local I mean the monitoring tool must be executed from the same machine (and in some cases the same user that is running the JVM) to connect to the JVM directly. If you are using jconsole, for example, then you must have access to a GUI (X-Windows or Windows) to display the jconsole output. This is the easist way of monitoring without doing too much configration but is not always practical. Java offers a remote monitorig capability to allow yo to connect to a remotely executing JVM from a console (like jconsole). To use this facility additional JVM options must be added to the command line that started the JVM. Details of the additional options for the version of the Java you are running is located at the JMX information site. Typically to remotely connect to a running JVM that JVM must be configured with the following categories of options: JMX Port - The JVM must allow connections on a listening port specified on the command line Connection security - The connection to the JVM can be secured. This is recommended as JMX is not just a monitoring protocol it is a managemet protocol. It is possible to change values in a running JVM using JMX and there are NO "Are you sure?" safeguards. For a Oracle Utilities Application Framework based application there are a few guidelines when configuring and using this JMX based remote monitoring of the JVM's: Online JVM - The JVM used to run the online system is embedded within the J2EE Web Application Server. To enable JMX monitoring on this JVM you can either change the startup script that starts the Web Application Server or check whether your J2EE Web Application natively supports JVM statistics collection. Child JVM's (COBOL only) - The Child JVM's should not be monitored using this method as they are recycled regularly by the configuration and therefore statistics collected are of little value. Batch Threadpoools - Batch already has a JMX interface (which will be covered in another article). Additional monitoring can be enabled but the base supported monitoring is sufficient for most needs. If you are an Oracle Utilities Application Framework site, then you can specify the additional options for JMX Java monitoring on the OPTS paramaters supported for each component of the architecture. Just ensure the port numbers used are unique for each JVM running on any machine.

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  • Using CMS for App Configuration - Part 1, Deploying Umbraco

    - by Elton Stoneman
    Originally posted on: http://geekswithblogs.net/EltonStoneman/archive/2014/06/04/using-cms-for-app-configurationndashpart-1-deploy-umbraco.aspxSince my last post on using CMS for semi-static API content, How about a new platform for your next API… a CMS?, I’ve been using the idea for centralized app configuration, and this post is the first in a series that will walk through how to do that, step-by-step. The approach gives you a platform-independent, easily configurable way to specify your application configuration for different environments, with a built-in approval workflow, change auditing and the ability to easily rollback to previous settings. It’s like Azure Web and Worker Roles where you can specify settings that change at runtime, but it's not specific to Azure - you can use it for any app that needs changeable config, provided it can access the Internet. The series breaks down into four posts: Deploying Umbraco – the CMS that will store your configurable settings and the current values; Publishing your config – create a document type that encapsulates your settings and a template to expose them as JSON; Consuming your config – in .NET, a simple client that uses dynamic objects to access settings; Config lifecycle management – how to publish, audit, and rollback settings. Let’s get started. Deploying Umbraco There’s an Umbraco package on Azure Websites, so deploying your own instance is easy – but there are a couple of things to watch out for, so this step-by-step will put you in a good place. Create From Gallery The easiest way to get started is with an Azure subscription, navigate to add a new Website and then Create From Gallery. Under CMS, you’ll see an Umbraco package (currently at version 7.1.3): Configure Your App For high availability and scale, you’ll want your CMS on separate kit from anything else you have in Azure, so in the configuration of Umbraco I’d create a new SQL Azure database – which Umbraco will use to store all its content: You can use the free 20mb database option if you don’t have demanding NFRs, or if you’re just experimenting. You’ll need to specify a password for a SQL Server account which the Umbraco service will use, and changing from the default username umbracouser is probably wise. Specify Database Settings You can create a new database on an existing server if you have one, or create new. If you create a new server *do not* use the same username for the database server login as you used for the Umbraco account. If you do, the deployment will fail later. Think of this as the SQL Admin account that you can use for managing the db, the previous account was the service account Umbraco uses to connect. Make Tea If you have a fast kettle. It takes about two minutes for Azure to create and provision the website and the database. Install Umbraco So far we’ve deployed an empty instance of Umbraco using the Azure package, and now we need to browse to the site and complete installation. My Website was called my-app-config, so to complete installation I browse to http://my-app-config.azurewebsites.net:   Enter the credentials you want to use to login – this account will have full admin rights to the Umbraco instance. Note that between deploying your new Umbraco instance and completing installation in this step, anyone can browse to your website and complete the installation themselves with their own credentials, if they know the URL. Remote possibility, but it’s there. From this page *do not* click the big green Install button. If you do, Umbraco will configure itself with a local SQL Server CE database (.sdf file on the Web server), and ignore the SQL Azure database you’ve carefully provisioned and may be paying for. Instead, click on the Customize link and: Configure Your Database You need to enter your SQL Azure database details here, so you’ll have to get the server name from the Azure Management Console. You don’t need to explicitly grant access to your Umbraco website for the database though. Click Continue and you’ll be offered a “starter” website to install: If you don’t know Umbraco at all (but you are familiar with ASP.NET MVC) then a starter website is worthwhile to see how it all hangs together. But after a while you’ll have a bunch of artifacts in your CMS that you don’t want and you’ll have to work out which you can safely delete. So I’d click “No thanks, I do not want to install a starter website” and give yourself a clean Umbraco install. When it completes, the installation will log you in to the welcome screen for managing Umbraco – which you can access from http://my-app-config.azurewebsites.net/umbraco: That’s It Easy. Umbraco is installed, using a dedicated SQL Azure instance that you can separately scale, sync and backup, and ready for your content. In the next post, we’ll define what our app config looks like, and publish some settings for the dev environment.

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  • SOA Suite Integration: Part 1: Building a Web Service

    - by Anthony Shorten
    Over the next few weeks I will be posting blog entries outlying the SOA Suite integration of the Oracle Utilities Application Framework. This will illustrate how easy it is to integrate by providing some samples. I will use a consistent set of features as examples. The examples will be simple and while will not illustrate ALL the possibilities it will illustrate the relative ease of integration. Think of them as a foundation. You can obviously build upon them. Now, to ease a few customers minds, this series will certainly feature the latest version of SOA Suite and the latest version of Oracle Utilities Application Framework but the principles will apply to past versions of both those products. So if you have Oracle SOA Suite 10g or are a customer of Oracle Utilities Application Framework V2.1 or above most of what I will show you will work with those versions. It is just easier in Oracle SOA Suite 11g and Oracle Utilities Application Framework V4.x. This first posting will not feature SOA Suite at all but concentrate on the capability for the Oracle Utilities Application Framework to create Web Services you can use for integration. The XML Application Integration (XAI) component of the Oracle Utilities Application Framework allows product objects to be exposed as XML based transactions or as Web Services (or both). XAI was written before Web Services became fashionable and has allowed customers of our products to provide a consistent interface into and out of our product line. XAI has been enhanced over the last few years to take advantages of the maturing landscape of Web Services in the market place to a point where it now easier to integrate to SOA infrastructure. There are a number of object types that can be exposed as Web Services: Maintenance Objects – These are the lowest level objects that can be exposed as Web Services. Customers of past versions of the product will be familiar with XAI services based upon Maintenance Objects as they used to be the only method of generating Web Services. These are still supported for background compatibility but are starting to become less popular as they were strict in their structure and were solely attribute based. To generate Maintenance Object based Web Services definition you need to use the XAI Schema Editor component. Business Objects – In Oracle Utilities Application Framework V2.1 we introduced the concept of Business Objects. These are site or industry specific objects that are based upon Maintenance Objects. These allow sites to respecify, in configuration, the structure and elements of a Maintenance Object and other Business Objects (they are true objects with support for inheritance, polymorphism, encapsulation etc.). These can be exposed as Web Services. Business Services – As with Business Objects, we introduced Business Services in Oracle Utilities Application Framework V2.1 which allowed applications services and query zones to be expressed as custom services. These can then be exposed as Web Services via the Business Service definition. Service Scripts - As with Business Objects and Business Services, we introduced Service Scripts in Oracle Utilities Application Framework V2.1. These allow services and/objects to be combined into complex objects or simply expose common routines as callable scripts. These can also be defined as Web Services. For the purpose of this series we will restrict ourselves to Business Objects. The techniques can apply to any of the objects discussed above. Now, lets get to the important bit of this blog post, the creation of a Web Service. To build a Business Object, you first logon to the product and navigate to the Administration Menu by selecting the Admin Menu from the Menu action on left top of the screen (next to Home). A popup menu will appear with the menu’s available. If you do not see the Admin menu then you do not have authority to use it. Here is an example: Navigate to the B menu and select the + symbol next to the Business Object menu item. This indicates that you want to ADD a new Business Object. This menu will appear if you are running Alphabetic mode in your installation (I almost forgot that point). You will be presented with the Business Object maintenance screen. You will fill out the following on the first tab (at a minimum): Business Object – The name of the Business Object. Typically you will make it descriptive and also prefix with CM to denote it as a customization (you can easily find it if you prefix it). As I running this on my personal copy of the product I will use my initials as the prefix and call the sample Web Service “AS-User”. Description – A short description of the object to tell others what it is used for. For my example, I will use “Anthony Shorten’s User Object”. Detailed Description – You can add a long description to help other developers understand your object. I am just going to specify “Anthony Shorten’s Test Object for SOA Suite Integration”. Maintenance Object – As this Business Service is going to be based upon a Maintenance Object I will specify the desired Maintenance Object. In this example, I have decided to use the Framework object USER. Now, I chose this for a number of reasons. It is meaningful, simple and is across all our product lines. I could choose ANY maintenance object I wished to expose (including any custom ones, if I had them). Parent Business Object – If I was not using a Maintenance Object but building a child Business Object against another Business Object, then I would specify the Parent Business Object here. I am not using Parent’s so I will leave this blank. You either use Parent Business Object or Maintenance Object not both. Application Service – Business Objects like other objects are subject to security. You can attach an Application Service to an object to specify which groups of users (remember services are attached to user groups not users) have appropriate access to the object. I will use a default service provided with the product, F1-DFLTS ,as this is just a demonstration so I do not have to be too sophisticated about security. Instance Control – This allows the object to create instances in its objects. You can specify a Business Object purely to hold rules. I am being simple here so I will set it to Allow New Instances to allow the Business Object to be used to create, read, update and delete user records. The rest of the tab I will leave empty as I want this to be a very simple object. Other options allow lots of flexibility. The contents should look like this: Before saving your work, you need to navigate to the Schema tab and specify the contents of your object. I will save some time. When you create an object the schema will only contain the basic root elements of the object (in fact only the schema tag is visible). When you go to the Schema Tab, on the dashboard you will see a BO Schema zone with a solitary button. This will allow you to Generate the Schema for you from our metadata. Click on the Generate button to generate a basic schema from the metadata. You will now see a Schema with the element tags and references to the metadata of the Maintenance object (in the mapField attribute). I could spend a while outlining all the ways you can change the schema with defaults, formatting, tagging etc but the online help has plenty of great examples to illustrate this. You can use the Schema Tips zone in the for more details of the available customizations. Note: The tags are generated from the language pack you have installed. The sample is English so the tags are in English (which is the base language of all installations). If you are using a language pack then the tags will be generated in the language of the user that generated the object. At this point you can save your Business Object by pressing the Save action. At this point you have a basic Business Object based on the USER maintenance object ready for use but it is not defined as a Web Service yet. To do this you need to define the newly created Business Object as an XAI Inbound Service. The easiest and quickest way is to select + off the XAI Inbound Service off the context menu on the Business Object maintenance screen. This will prepopulate the service definition with the following: Adapter – This will be set to Business Adaptor. This indicates that the service is either Business Object, Business Service or Service Script based. Schema Type – Whether the object is a Business Object, Business Service or Service Script. In this case it is a Business Object. Schema Name – The name of the object. In this case it is the Business Object AS-User. Active – Set to Yes. This means the service is available upon startup automatically. You can enable and disable services as needed. Transaction Type – A default transaction type as this is Business Object Service. More about this in later postings. In our case we use the default Read. This means that if we only specify data and not a transaction type then the product will assume you want to issue a read against the object. You need to fill in the following: XAI Inbound Service – The name of the Web Service. Usually people use the same name as the underlying object , in the case of this example, but this can match your sites interfacing standards. By the way you can define multiple XAI Inbound Services/Web Services against the same object if you want. Description and Detail Description – Documentation for your Web Service. I just supplied some basic documentation for this demonstration. You can now save the service definition. Note: There are lots of other options on this screen that allow for behavior of your service to be specified. I will leave them blank for now. When you save the service you are issued with two new pieces of information. XAI Inbound Service Id is a randomly generated identifier used internally by the XAI Servlet. WSDL URL is the WSDL standard URL used for integration. We will take advantage of that in later posts. An example of the definition is shown below: Now you have defined the service but it will only be available when the next server restart or when you flush the data cache. XAI Inbound Services are cached for performance so the cache needs to be told of this new service. To refresh the cache you can use the Admin –> X –> XAI Command menu item. From the command dropdown select Refresh Registry and press Send Command. You will see an XML of the command sent to the server (the presence of the XML means it is finished). If you have an error around the authorization, then check your default user and password settings on the XAI Options menu item. Be careful with flushing the cache as the cache is shared (unless of course you are the only Web Service user on the system – In that case it only affects you). The Web Service is NOW available to be used. To perform a simple test of your new Web Service, navigate to the Admin –> X –> XAI Submission menu item. You will see an open XML request tab. You need to type in the request XML you want to test in the Main tab. The first tag is the XAI Inbound Service Name and the elements are as per your schema (minus the schema tag itself as that is only used internally). My example is as follows (I want to return the details of user SYSUSER) – Remember to close tags. Hitting the Save button will issue the XML and return the response according to the Business Object schema. Now before you panic, you noticed that it did not ask for credentials. It propagates the online credentials to the service call on this function. You now have a Web Service you can use for integration. We will reuse this information in subsequent posts. The process I just described can be used for ANY object in the system you want to expose. This whole process at a minimum can take under a minute. Obviously I only showed the basics but you can at least get an appreciation of the ease of defining a Web Service (just by using a browser). The next posts now build upon this. Hope you enjoyed the post.

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  • Another Marketing Conference, part two – the afternoon

    - by Roger Hart
    In my previous post, I’ve covered the morning sessions at AMC2012. Here’s the rest of the write-up. I’ve skipped Charles Nixon’s session which was a blend of funky futurism and professional development advice, but you can see his slides here. I’ve also skipped the Google presentation, as it was a little thin on insight. 6 – Brand ambassadors: Getting universal buy in across the organisation, Vanessa Northam Slides are here This was the strongest enforcement of the idea that brand and campaign values need to be delivered throughout the organization if they’re going to work. Vanessa runs internal communications at e-on, and shared her experience of using internal comms to align an organization and thereby get the most out of a campaign. She views the purpose of internal comms as: “…to help leaders, to communicate the purpose and future of an organization, and support change.” This (and culture) primes front line staff, which creates customer experience and spreads brand. You ensure a whole organization knows what’s going on with both internal and external comms. If everybody is aligned and informed, if everybody can clearly articulate your brand and campaign goals, then you can turn everybody into an advocate. Alignment is a powerful tool for delivering a consistent experience and message. The pathological counter example is the one in which a marketing message goes out, which creates inbound customer contacts that front line contact staff haven’t been briefed to handle. The NatWest campaign was again mentioned in this context. The good example was e-on’s cheaper tariff campaign. Building a groundswell of internal excitement, and even running an internal launch meant everyone could contribute to a good customer experience. They found that meter readers were excited – not a group they’d considered as obvious in providing customer experience. But they were a group that has a lot of face-to-face contact with customers, and often were asked questions they may not have been briefed to answer. Being able to communicate a simple new message made it easier for them, and also let them become a sales and marketing asset to the organization. 7 – Goodbye Internet, Hello Outernet: the rise and rise of augmented reality, Matt Mills I wasn’t going to write this up, because it was essentially a sales demo for Aurasma. But the technology does merit some discussion. Basically, it replaces QR codes with visual recognition, and provides a simple-looking back end for attaching content. It’s quite sexy. But here’s my beef with it: QR codes had a clear visual language – when you saw one you knew what it was and what to do with it. They were clunky, but they had the “getting started” problem solved out of the box once you knew what you were looking at. However, they fail because QR code reading isn’t native to the platform. You needed an app, which meant you needed to know to download one. Consequentially, you can’t use QR codes with and ubiquity, or depend on them. This means marketers, content providers, etc, never pushed them, and they remained and awkward oddity, a minority sport. Aurasma half solves problem two, and re-introduces problem one, making it potentially half as useful as a QR code. It’s free, and you can apparently build it into your own apps. Add to that the likelihood of it becoming native to the platform if it takes off, and it may have legs. I guess we’ll see. 8 – We all need to code, Helen Mayor Great title – good point. If there was anybody in the room who didn’t at least know basic HTML, and if Helen’s presentation inspired them to learn, that’s fantastic. However, this was a half hour sales pitch for a basic coding training course. Beyond advocating coding skills it contained no useful content. Marketers may also like to consider some of these resources if they’re looking to learn code: Code Academy – free interactive tutorials Treehouse – learn web design, web dev, or app dev WebPlatform.org – tutorials and documentation for web tech  11 – Understanding our inner creativity, Margaret Boden This session was the most theoretical and probably least actionable of the day. It also held my attention utterly. Margaret spoke fluently, fascinatingly, without slides, on the subject of types of creativity and how they work. It was splendid. Yes, it raised a wry smile whenever she spoke of “the content of advertisements” and gave an example from 1970s TV ads, but even without the attempt to meet the conference’s theme this would have been thoroughly engaging. There are, Margaret suggested, three types of creativity: Combinatorial creativity The most common form, and consisting of synthesising ideas from existing and familiar concepts and tropes. Exploratory creativity Less common, this involves exploring the limits and quirks of a particular constraint or style. Transformational creativity This is uncommon, and arises from finding a way to do something that the existing rules would hold to be impossible. In essence, this involves breaking one of the constraints that exploratory creativity is composed from. Combinatorial creativity, she suggested, is particularly important for attaching favourable ideas to existing things. As such is it probably worth developing for marketing. Exploratory creativity may then come into play in something like developing and optimising an idea or campaign that now has momentum. Transformational creativity exists at the edges of this exploration. She suggested that products may often be transformational, but that marketing seemed unlikely to in her experience. This made me wonder about Listerine. Crucially, transformational creativity is characterised by there being some element of continuity with the strictures of previous thinking. Once it has happened, there may be  move from a revolutionary instance into an explored style. Again, from a marketing perspective, this seems to chime well with the thinking in Youngme Moon’s book: Different Talking about the birth of Modernism is visual art, Margaret pointed out that transformational creativity has historically risked a backlash, demanding what is essentially an education of the market. This is best accomplished by referring back to the continuities with the past in order to make the new familiar. Thoughts The afternoon is harder to sum up than the morning. It felt less concrete, and was troubled by a short run of poor presentations in the middle. Mainly, I found myself wrestling with the internal comms issue. It’s one of those things that seems astonishingly obvious in hindsight, but any campaign – particularly any large one – is doomed if the people involved can’t believe in it. We’ve run things here that haven’t gone so well, of course we have; who hasn’t? I’m not going to air any laundry, but people not being informed (much less aligned) feels like a common factor. It’s tough though. Managing and anticipating information needs across an organization of any size can’t be easy. Even the simple things like ensuring sales and support departments know what’s in a product release, and what messages go with it are easy to botch. The thing I like about framing this as a brand and campaign advocacy problem is that it makes it likely to get addressed. Better is always sexier than less-worse. Any technical communicator who’s ever felt crowded out by a content strategist or marketing copywriter  knows this – increasing revenue gets a seat at the table far more readily than reducing support costs, even if the financial impact is identical. So that’s it from AMC. The big thought-provokers were social buying behaviour and eliciting behaviour change, and the value of internal communications in ensuring successful campaigns and continuity of customer experience. I’ll be chewing over that for a while, and I’d definitely return next year.      

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  • Diving into OpenStack Network Architecture - Part 1

    - by Ronen Kofman
    v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} rkofman Normal rkofman 83 3045 2014-05-23T21:11:00Z 2014-05-27T06:58:00Z 3 1883 10739 Oracle Corporation 89 25 12597 12.00 140 Clean Clean false false false false EN-US X-NONE HE 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-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi; mso-bidi-language:AR-SA;} Before we begin OpenStack networking has very powerful capabilities but at the same time it is quite complicated. In this blog series we will review an existing OpenStack setup using the Oracle OpenStack Tech Preview and explain the different network components through use cases and examples. The goal is to show how the different pieces come together and provide a bigger picture view of the network architecture in OpenStack. This can be very helpful to users making their first steps in OpenStack or anyone wishes to understand how networking works in this environment.  We will go through the basics first and build the examples as we go. According to the recent Icehouse user survey and the one before it, Neutron with Open vSwitch plug-in is the most widely used network setup both in production and in POCs (in terms of number of customers) and so in this blog series we will analyze this specific OpenStack networking setup. As we know there are many options to setup OpenStack networking and while Neturon + Open vSwitch is the most popular setup there is no claim that it is either best or the most efficient option. Neutron + Open vSwitch is an example, one which provides a good starting point for anyone interested in understanding OpenStack networking. Even if you are using different kind of network setup such as different Neutron plug-in or even not using Neutron at all this will still be a good starting point to understand the network architecture in OpenStack. The setup we are using for the examples is the one used in the Oracle OpenStack Tech Preview. Installing it is simple and it would be helpful to have it as reference. In this setup we use eth2 on all servers for VM network, all VM traffic will be flowing through this interface.The Oracle OpenStack Tech Preview is using VLANs for L2 isolation to provide tenant and network isolation. The following diagram shows how we have configured our deployment: This first post is a bit long and will focus on some basic concepts in OpenStack networking. The components we will be discussing are Open vSwitch, network namespaces, Linux bridge and veth pairs. Note that this is not meant to be a comprehensive review of these components, it is meant to describe the component as much as needed to understand OpenStack network architecture. All the components described here can be further explored using other resources. Open vSwitch (OVS) In the Oracle OpenStack Tech Preview OVS is used to connect virtual machines to the physical port (in our case eth2) as shown in the deployment diagram. OVS contains bridges and ports, the OVS bridges are different from the Linux bridge (controlled by the brctl command) which are also used in this setup. To get started let’s view the OVS structure, use the following command: # ovs-vsctl show 7ec51567-ab42-49e8-906d-b854309c9edf     Bridge br-int         Port br-int             Interface br-int type: internal         Port "int-br-eth2"             Interface "int-br-eth2"     Bridge "br-eth2"         Port "br-eth2"             Interface "br-eth2" type: internal         Port "eth2"             Interface "eth2"         Port "phy-br-eth2"             Interface "phy-br-eth2" ovs_version: "1.11.0" We see a standard post deployment OVS on a compute node with two bridges and several ports hanging off of each of them. The example above is a compute node without any VMs, we can see that the physical port eth2 is connected to a bridge called “br-eth2”. We also see two ports "int-br-eth2" and "phy-br-eth2" which are actually a veth pair and form virtual wire between the two bridges, veth pairs are discussed later in this post. When a virtual machine is created a port is created on one the br-int bridge and this port is eventually connected to the virtual machine (we will discuss the exact connectivity later in the series). Here is how OVS looks after a VM was launched: # ovs-vsctl show efd98c87-dc62-422d-8f73-a68c2a14e73d     Bridge br-int         Port "int-br-eth2"             Interface "int-br-eth2"         Port br-int             Interface br-int type: internal         Port "qvocb64ea96-9f" tag: 1             Interface "qvocb64ea96-9f"     Bridge "br-eth2"         Port "phy-br-eth2"             Interface "phy-br-eth2"         Port "br-eth2"             Interface "br-eth2" type: internal         Port "eth2"             Interface "eth2" ovs_version: "1.11.0" Bridge "br-int" now has a new port "qvocb64ea96-9f" which connects to the VM and tagged with VLAN 1. Every VM which will be launched will add a port on the “br-int” bridge for every network interface the VM has. Another useful command on OVS is dump-flows for example: # ovs-ofctl dump-flows br-int NXST_FLOW reply (xid=0x4): cookie=0x0, duration=735.544s, table=0, n_packets=70, n_bytes=9976, idle_age=17, priority=3,in_port=1,dl_vlan=1000 actions=mod_vlan_vid:1,NORMAL cookie=0x0, duration=76679.786s, table=0, n_packets=0, n_bytes=0, idle_age=65534, hard_age=65534, priority=2,in_port=1 actions=drop cookie=0x0, duration=76681.36s, table=0, n_packets=68, n_bytes=7950, idle_age=17, hard_age=65534, priority=1 actions=NORMAL As we see the port which is connected to the VM has the VLAN tag 1. However the port on the VM network (eth2) will be using tag 1000. OVS is modifying the vlan as the packet flow from the VM to the physical interface. In OpenStack the Open vSwitch agent takes care of programming the flows in Open vSwitch so the users do not have to deal with this at all. If you wish to learn more about how to program the Open vSwitch you can read more about it at http://openvswitch.org looking at the documentation describing the ovs-ofctl command. Network Namespaces (netns) Network namespaces is a very cool Linux feature can be used for many purposes and is heavily used in OpenStack networking. Network namespaces are isolated containers which can hold a network configuration and is not seen from outside of the namespace. A network namespace can be used to encapsulate specific network functionality or provide a network service in isolation as well as simply help to organize a complicated network setup. Using the Oracle OpenStack Tech Preview we are using the latest Unbreakable Enterprise Kernel R3 (UEK3), this kernel provides a complete support for netns. Let's see how namespaces work through couple of examples to control network namespaces we use the ip netns command: Defining a new namespace: # ip netns add my-ns # ip netns list my-ns As mentioned the namespace is an isolated container, we can perform all the normal actions in the namespace context using the exec command for example running the ifconfig command: # ip netns exec my-ns ifconfig -a lo        Link encap:Local Loopback           LOOPBACK  MTU:16436 Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b) We can run every command in the namespace context, this is especially useful for debug using tcpdump command, we can ping or ssh or define iptables all within the namespace. Connecting the namespace to the outside world: There are various ways to connect into a namespaces and between namespaces we will focus on how this is done in OpenStack. OpenStack uses a combination of Open vSwitch and network namespaces. OVS defines the interfaces and then we can add those interfaces to namespace. So first let's add a bridge to OVS: # ovs-vsctl add-br my-bridge Now let's add a port on the OVS and make it internal: # ovs-vsctl add-port my-bridge my-port # ovs-vsctl set Interface my-port type=internal And let's connect it into the namespace: # ip link set my-port netns my-ns Looking inside the namespace: # ip netns exec my-ns ifconfig -a lo        Link encap:Local Loopback           LOOPBACK  MTU:65536 Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b) my-port   Link encap:Ethernet HWaddr 22:04:45:E2:85:21           BROADCAST  MTU:1500 Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b) Now we can add more ports to the OVS bridge and connect it to other namespaces or other device like physical interfaces. Neutron is using network namespaces to implement network services such as DCHP, routing, gateway, firewall, load balance and more. In the next post we will go into this in further details. Linux Bridge and veth pairs Linux bridge is used to connect the port from OVS to the VM. Every port goes from the OVS bridge to a Linux bridge and from there to the VM. The reason for using regular Linux bridges is for security groups’ enforcement. Security groups are implemented using iptables and iptables can only be applied to Linux bridges and not to OVS bridges. Veth pairs are used extensively throughout the network setup in OpenStack and are also a good tool to debug a network problem. Veth pairs are simply a virtual wire and so veths always come in pairs. Typically one side of the veth pair will connect to a bridge and the other side to another bridge or simply left as a usable interface. In this example we will create some veth pairs, connect them to bridges and test connectivity. This example is using regular Linux server and not an OpenStack node: Creating a veth pair, note that we define names for both ends: # ip link add veth0 type veth peer name veth1 # ifconfig -a . . veth0     Link encap:Ethernet HWaddr 5E:2C:E6:03:D0:17           BROADCAST MULTICAST  MTU:1500 Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b) veth1     Link encap:Ethernet HWaddr E6:B6:E2:6D:42:B8           BROADCAST MULTICAST  MTU:1500 Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000           RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b) . . To make the example more meaningful this we will create the following setup: veth0 => veth1 => br-eth3 => eth3 ======> eth2 on another Linux server br-eth3 – a regular Linux bridge which will be connected to veth1 and eth3 eth3 – a physical interface with no IP on it, connected to a private network eth2 – a physical interface on the remote Linux box connected to the private network and configured with the IP of 50.50.50.1 Once we create the setup we will ping 50.50.50.1 (the remote IP) through veth0 to test that the connection is up: # brctl addbr br-eth3 # brctl addif br-eth3 eth3 # brctl addif br-eth3 veth1 # brctl show bridge name     bridge id               STP enabled     interfaces br-eth3         8000.00505682e7f6       no              eth3                                                         veth1 # ifconfig veth0 50.50.50.50 # ping -I veth0 50.50.50.51 PING 50.50.50.51 (50.50.50.51) from 50.50.50.50 veth0: 56(84) bytes of data. 64 bytes from 50.50.50.51: icmp_seq=1 ttl=64 time=0.454 ms 64 bytes from 50.50.50.51: icmp_seq=2 ttl=64 time=0.298 ms When the naming is not as obvious as the previous example and we don't know who are the paired veth interfaces we can use the ethtool command to figure this out. The ethtool command returns an index we can look up using ip link command, for example: # ethtool -S veth1 NIC statistics: peer_ifindex: 12 # ip link . . 12: veth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 Summary That’s all for now, we quickly reviewed OVS, network namespaces, Linux bridges and veth pairs. These components are heavily used in the OpenStack network architecture we are exploring and understanding them well will be very useful when reviewing the different use cases. In the next post we will look at how the OpenStack network is laid out connecting the virtual machines to each other and to the external world. @RonenKofman

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  • Adding Volcanos and Options - Earthquake Locator, part 2

    - by Bobby Diaz
    Since volcanos are often associated with earthquakes, and vice versa, I decided to show recent volcanic activity on the Earthquake Locator map.  I am pulling the data from a website created for a joint project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program, found here.  They provide a Weekly Volcanic Activity Report as an RSS feed.   I started implementing this new functionality by creating a new Volcano entity in the domain model and adding the following to the EarthquakeService class (I also factored out the common reading/parsing helper methods to a separate FeedReader class that can be used by multiple domain service classes):           private static readonly string VolcanoFeedUrl =             ConfigurationManager.AppSettings["VolcanoFeedUrl"];           /// <summary>         /// Gets the volcano data for the previous week.         /// </summary>         /// <returns>A queryable collection of <see cref="Volcano"/> objects.</returns>         public IQueryable<Volcano> GetVolcanos()         {             var feed = FeedReader.Load(VolcanoFeedUrl);             var list = new List<Volcano>();               if ( feed != null )             {                 foreach ( var item in feed.Items )                 {                     var quake = CreateVolcano(item);                     if ( quake != null )                     {                         list.Add(quake);                     }                 }             }               return list.AsQueryable();         }           /// <summary>         /// Creates a <see cref="Volcano"/> object for each item in the RSS feed.         /// </summary>         /// <param name="item">The RSS item.</param>         /// <returns></returns>         private Volcano CreateVolcano(SyndicationItem item)         {             Volcano volcano = null;             string title = item.Title.Text;             string desc = item.Summary.Text;             double? latitude = null;             double? longitude = null;               FeedReader.GetGeoRssPoint(item, out latitude, out longitude);               if ( !String.IsNullOrEmpty(title) )             {                 title = title.Substring(0, title.IndexOf('-'));             }             if ( !String.IsNullOrEmpty(desc) )             {                 desc = String.Join("\n\n", desc                         .Replace("<p>", "")                         .Split(                             new string[] { "</p>" },                             StringSplitOptions.RemoveEmptyEntries)                         .Select(s => s.Trim())                         .ToArray())                         .Trim();             }               if ( latitude != null && longitude != null )             {                 volcano = new Volcano()                 {                     Id = item.Id,                     Title = title,                     Description = desc,                     Url = item.Links.Select(l => l.Uri.OriginalString).FirstOrDefault(),                     Latitude = latitude.GetValueOrDefault(),                     Longitude = longitude.GetValueOrDefault()                 };             }               return volcano;         } I then added the corresponding LoadVolcanos() method and Volcanos collection to the EarthquakeViewModel class in much the same way I did with the Earthquakes in my previous article in this series. Now that I am starting to add more information to the map, I wanted to give the user some options as to what is displayed and allowing them to choose what gets turned off.  I have updated the MainPage.xaml to look like this:   <UserControl x:Class="EarthquakeLocator.MainPage"     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"     xmlns:basic="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls"     xmlns:bing="clr-namespace:Microsoft.Maps.MapControl;assembly=Microsoft.Maps.MapControl"     xmlns:vm="clr-namespace:EarthquakeLocator.ViewModel"     mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480" >     <UserControl.Resources>         <DataTemplate x:Key="EarthquakeTemplate">             <Ellipse Fill="Red" Stroke="Black" StrokeThickness="1"                      Width="{Binding Size}" Height="{Binding Size}"                      bing:MapLayer.Position="{Binding Location}"                      bing:MapLayer.PositionOrigin="Center">                 <ToolTipService.ToolTip>                     <StackPanel>                         <TextBlock Text="{Binding Title}" FontSize="14" FontWeight="Bold" />                         <TextBlock Text="{Binding UtcTime}" />                         <TextBlock Text="{Binding LocalTime}" />                         <TextBlock Text="{Binding DepthDesc}" />                     </StackPanel>                 </ToolTipService.ToolTip>             </Ellipse>         </DataTemplate>           <DataTemplate x:Key="VolcanoTemplate">             <Polygon Fill="Gold" Stroke="Black" StrokeThickness="1" Points="0,10 5,0 10,10"                      bing:MapLayer.Position="{Binding Location}"                      bing:MapLayer.PositionOrigin="Center"                      MouseLeftButtonUp="Volcano_MouseLeftButtonUp">                 <ToolTipService.ToolTip>                     <StackPanel>                         <TextBlock Text="{Binding Title}" FontSize="14" FontWeight="Bold" />                         <TextBlock Text="Click icon for more information..." />                     </StackPanel>                 </ToolTipService.ToolTip>             </Polygon>         </DataTemplate>     </UserControl.Resources>       <UserControl.DataContext>         <vm:EarthquakeViewModel AutoLoadData="True" />     </UserControl.DataContext>       <Grid x:Name="LayoutRoot">           <bing:Map x:Name="map" CredentialsProvider="--Your-Bing-Maps-Key--"                   Center="{Binding MapCenter, Mode=TwoWay}"                   ZoomLevel="{Binding ZoomLevel, Mode=TwoWay}">               <bing:MapItemsControl ItemsSource="{Binding Earthquakes}"                                   ItemTemplate="{StaticResource EarthquakeTemplate}" />               <bing:MapItemsControl ItemsSource="{Binding Volcanos}"                                   ItemTemplate="{StaticResource VolcanoTemplate}" />         </bing:Map>           <basic:TabControl x:Name="tabs" VerticalAlignment="Bottom" MaxHeight="25" Opacity="0.7">             <basic:TabItem Margin="90,0,-90,0" MouseLeftButtonUp="TabItem_MouseLeftButtonUp">                 <basic:TabItem.Header>                     <TextBlock x:Name="txtHeader" Text="Options"                                FontSize="13" FontWeight="Bold" />                 </basic:TabItem.Header>                   <StackPanel Orientation="Horizontal">                     <TextBlock Text="Earthquakes:" FontWeight="Bold" Margin="3" />                     <StackPanel Margin="3">                         <CheckBox Content=" &lt; 4.0"                                   IsChecked="{Binding ShowLt4, Mode=TwoWay}" />                         <CheckBox Content="4.0 - 4.9"                                   IsChecked="{Binding Show4s, Mode=TwoWay}" />                         <CheckBox Content="5.0 - 5.9"                                   IsChecked="{Binding Show5s, Mode=TwoWay}" />                     </StackPanel>                       <StackPanel Margin="10,3,3,3">                         <CheckBox Content="6.0 - 6.9"                                   IsChecked="{Binding Show6s, Mode=TwoWay}" />                         <CheckBox Content="7.0 - 7.9"                                   IsChecked="{Binding Show7s, Mode=TwoWay}" />                         <CheckBox Content="8.0 +"                                   IsChecked="{Binding ShowGe8, Mode=TwoWay}" />                     </StackPanel>                       <TextBlock Text="Other:" FontWeight="Bold" Margin="50,3,3,3" />                     <StackPanel Margin="3">                         <CheckBox Content="Volcanos"                                   IsChecked="{Binding ShowVolcanos, Mode=TwoWay}" />                     </StackPanel>                 </StackPanel>               </basic:TabItem>         </basic:TabControl>       </Grid> </UserControl> Notice that I added a VolcanoTemplate that uses a triangle-shaped Polygon to represent the Volcano locations, and I also added a second <bing:MapItemsControl /> tag to the map to bind to the Volcanos collection.  The TabControl found below the map houses the options panel that will present the user with several checkboxes so they can filter the different points based on type and other properties (i.e. Magnitude).  Initially, the TabItem is collapsed to reduce it's footprint, but the screen shot below shows the options panel expanded to reveal the available settings:     I have updated the Source Code and Live Demo to include these new features.   Happy Mapping!

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  • Installing Enterprise Library 5.0 - Enterprise Library 5.0 Tutorial Part 1

    Microsoft has released Enterprise Library on April 2010. it’s free you can download and install from “Download Enterprise Library”. you can also find older version of enterprise library 4.1 still if your project needs it for maintenance purpose. but I suggest go for 5.0 as it has great enhancements and improved UI configuration tool. Will it work only with Visual Studio 2008? Yes. Yes, it works with also .NET 3.5 and Visual Studio 2008. you can take advantage of new improved UI configuration tool which comes from enterprise library 5.0 with VS2008. Please find this Enterprise Library resources. I suggest to install it with documentation and hands on labs. you can also find community links. I’ll see you in my next blog serious where I provide introduction to various blocks of Enterprise Library 5.0. span.fullpost {display:none;}

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  • SQL SERVER – Index Created on View not Used Often – Observation of the View – Part 2

    - by pinaldave
    Earlier, I have written an article about SQL SERVER – Index Created on View not Used Often – Observation of the View. I received an email from one of the readers, asking if there would no problems when we create the Index on the base table. Well, we need to discuss this situation in two different cases. Before proceeding to the discussion, I strongly suggest you read my earlier articles. To avoid the duplication, I am not going to repeat the code and explanation over here. In all the earlier cases, I have explained in detail how Index created on the View is not utilized. SQL SERVER – Index Created on View not Used Often – Limitation of the View 12 SQL SERVER – Index Created on View not Used Often – Observation of the View SQL SERVER – Indexed View always Use Index on Table As per earlier blog posts, so far we have done the following: Create a Table Create a View Create Index On View Write SELECT with ORDER BY on View However, the blog reader who emailed me suggests the extension of the said logic, which is as follows: Create a Table Create a View Create Index On View Write SELECT with ORDER BY on View Create Index on the Base Table Write SELECT with ORDER BY on View After doing the last two steps, the question is “Will the query on the View utilize the Index on the View, or will it still use the Index of the base table?“ Let us first run the Create example. USE tempdb GO IF EXISTS (SELECT * FROM sys.views WHERE OBJECT_ID = OBJECT_ID(N'[dbo].[SampleView]')) DROP VIEW [dbo].[SampleView] GO IF EXISTS (SELECT * FROM sys.objects WHERE OBJECT_ID = OBJECT_ID(N'[dbo].[mySampleTable]') AND TYPE IN (N'U')) DROP TABLE [dbo].[mySampleTable] GO -- Create SampleTable CREATE TABLE mySampleTable (ID1 INT, ID2 INT, SomeData VARCHAR(100)) INSERT INTO mySampleTable (ID1,ID2,SomeData) SELECT TOP 100000 ROW_NUMBER() OVER (ORDER BY o1.name), ROW_NUMBER() OVER (ORDER BY o2.name), o2.name FROM sys.all_objects o1 CROSS JOIN sys.all_objects o2 GO -- Create View CREATE VIEW SampleView WITH SCHEMABINDING AS SELECT ID1,ID2,SomeData FROM dbo.mySampleTable GO -- Create Index on View CREATE UNIQUE CLUSTERED INDEX [IX_ViewSample] ON [dbo].[SampleView] ( ID2 ASC ) GO -- Select from view SELECT ID1,ID2,SomeData FROM SampleView ORDER BY ID2 GO -- Create Index on Original Table -- On Column ID1 CREATE UNIQUE CLUSTERED INDEX [IX_OriginalTable] ON mySampleTable ( ID1 ASC ) GO -- On Column ID2 CREATE UNIQUE NONCLUSTERED INDEX [IX_OriginalTable_ID2] ON mySampleTable ( ID2 ) GO -- Select from view SELECT ID1,ID2,SomeData FROM SampleView ORDER BY ID2 GO Now let us see the execution plans for both of the SELECT statement. Before Index on Base Table (with Index on View): After Index on Base Table (with Index on View): Looking at both executions, it is very clear that with or without, the View is using Indexes. Alright, I have written 11 disadvantages of the Views. Now I have written one case where the View is using Indexes. Anybody who says that I am being harsh on Views can say now that I found one place where Index on View can be helpful. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Optimization, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL View, SQLServer, T SQL, Technology

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  • Developing web apps using ASP.NET MVC 3, Razor and EF Code First - Part 1

    - by shiju
    In this post, I will demonstrate web application development using ASP. NET MVC 3, Razor and EF code First. This post will also cover Dependency Injection using Unity 2.0 and generic Repository and Unit of Work for EF Code First. The following frameworks will be used for this step by step tutorial. ASP.NET MVC 3 EF Code First CTP 5 Unity 2.0 Define Domain Model Let’s create domain model for our simple web application Category class public class Category {     public int CategoryId { get; set; }     [Required(ErrorMessage = "Name Required")]     [StringLength(25, ErrorMessage = "Must be less than 25 characters")]     public string Name { get; set;}     public string Description { get; set; }     public virtual ICollection<Expense> Expenses { get; set; } }   Expense class public class Expense {             public int ExpenseId { get; set; }            public string  Transaction { get; set; }     public DateTime Date { get; set; }     public double Amount { get; set; }     public int CategoryId { get; set; }     public virtual Category Category { get; set; } } We have two domain entities - Category and Expense. A single category contains a list of expense transactions and every expense transaction should have a Category. In this post, we will be focusing on CRUD operations for the entity Category and will be working on the Expense entity with a View Model object in the later post. And the source code for this application will be refactored over time. The above entities are very simple POCO (Plain Old CLR Object) classes and the entity Category is decorated with validation attributes in the System.ComponentModel.DataAnnotations namespace. Now we want to use these entities for defining model objects for the Entity Framework 4. Using the Code First approach of Entity Framework, we can first define the entities by simply writing POCO classes without any coupling with any API or database library. This approach lets you focus on domain model which will enable Domain-Driven Development for applications. EF code first support is currently enabled with a separate API that is runs on top of the Entity Framework 4. EF Code First is reached CTP 5 when I am writing this article. Creating Context Class for Entity Framework We have created our domain model and let’s create a class in order to working with Entity Framework Code First. For this, you have to download EF Code First CTP 5 and add reference to the assembly EntitFramework.dll. You can also use NuGet to download add reference to EEF Code First.    public class MyFinanceContext : DbContext {     public MyFinanceContext() : base("MyFinance") { }     public DbSet<Category> Categories { get; set; }     public DbSet<Expense> Expenses { get; set; }         }   The above class MyFinanceContext is derived from DbContext that can connect your model classes to a database. The MyFinanceContext class is mapping our Category and Expense class into database tables Categories and Expenses using DbSet<TEntity> where TEntity is any POCO class. When we are running the application at first time, it will automatically create the database. EF code-first look for a connection string in web.config or app.config that has the same name as the dbcontext class. If it is not find any connection string with the convention, it will automatically create database in local SQL Express database by default and the name of the database will be same name as the dbcontext class. You can also define the name of database in constructor of the the dbcontext class. Unlike NHibernate, we don’t have to use any XML based mapping files or Fluent interface for mapping between our model and database. The model classes of Code First are working on the basis of conventions and we can also use a fluent API to refine our model. The convention for primary key is ‘Id’ or ‘<class name>Id’.  If primary key properties are detected with type ‘int’, ‘long’ or ‘short’, they will automatically registered as identity columns in the database by default. Primary key detection is not case sensitive. We can define our model classes with validation attributes in the System.ComponentModel.DataAnnotations namespace and it automatically enforces validation rules when a model object is updated or saved. Generic Repository for EF Code First We have created model classes and dbcontext class. Now we have to create generic repository pattern for data persistence with EF code first. If you don’t know about the repository pattern, checkout Martin Fowler’s article on Repository Let’s create a generic repository to working with DbContext and DbSet generics. public interface IRepository<T> where T : class     {         void Add(T entity);         void Delete(T entity);         T GetById(long Id);         IEnumerable<T> All();     }   RepositoryBasse – Generic Repository class public abstract class RepositoryBase<T> where T : class { private MyFinanceContext database; private readonly IDbSet<T> dbset; protected RepositoryBase(IDatabaseFactory databaseFactory) {     DatabaseFactory = databaseFactory;     dbset = Database.Set<T>(); }   protected IDatabaseFactory DatabaseFactory {     get; private set; }   protected MyFinanceContext Database {     get { return database ?? (database = DatabaseFactory.Get()); } } public virtual void Add(T entity) {     dbset.Add(entity);            }        public virtual void Delete(T entity) {     dbset.Remove(entity); }   public virtual T GetById(long id) {     return dbset.Find(id); }   public virtual IEnumerable<T> All() {     return dbset.ToList(); } }   DatabaseFactory class public class DatabaseFactory : Disposable, IDatabaseFactory {     private MyFinanceContext database;     public MyFinanceContext Get()     {         return database ?? (database = new MyFinanceContext());     }     protected override void DisposeCore()     {         if (database != null)             database.Dispose();     } } Unit of Work If you are new to Unit of Work pattern, checkout Fowler’s article on Unit of Work . According to Martin Fowler, the Unit of Work pattern "maintains a list of objects affected by a business transaction and coordinates the writing out of changes and the resolution of concurrency problems." Let’s create a class for handling Unit of Work   public interface IUnitOfWork {     void Commit(); }   UniOfWork class public class UnitOfWork : IUnitOfWork {     private readonly IDatabaseFactory databaseFactory;     private MyFinanceContext dataContext;       public UnitOfWork(IDatabaseFactory databaseFactory)     {         this.databaseFactory = databaseFactory;     }       protected MyFinanceContext DataContext     {         get { return dataContext ?? (dataContext = databaseFactory.Get()); }     }       public void Commit()     {         DataContext.Commit();     } }   The Commit method of the UnitOfWork will call the commit method of MyFinanceContext class and it will execute the SaveChanges method of DbContext class.   Repository class for Category In this post, we will be focusing on the persistence against Category entity and will working on other entities in later post. Let’s create a repository for handling CRUD operations for Category using derive from a generic Repository RepositoryBase<T>.   public class CategoryRepository: RepositoryBase<Category>, ICategoryRepository     {     public CategoryRepository(IDatabaseFactory databaseFactory)         : base(databaseFactory)         {         }                } public interface ICategoryRepository : IRepository<Category> { } If we need additional methods than generic repository for the Category, we can define in the CategoryRepository. Dependency Injection using Unity 2.0 If you are new to Inversion of Control/ Dependency Injection or Unity, please have a look on my articles at http://weblogs.asp.net/shijuvarghese/archive/tags/IoC/default.aspx. I want to create a custom lifetime manager for Unity to store container in the current HttpContext.   public class HttpContextLifetimeManager<T> : LifetimeManager, IDisposable {     public override object GetValue()     {         return HttpContext.Current.Items[typeof(T).AssemblyQualifiedName];     }     public override void RemoveValue()     {         HttpContext.Current.Items.Remove(typeof(T).AssemblyQualifiedName);     }     public override void SetValue(object newValue)     {         HttpContext.Current.Items[typeof(T).AssemblyQualifiedName] = newValue;     }     public void Dispose()     {         RemoveValue();     } }   Let’s create controller factory for Unity in the ASP.NET MVC 3 application. public class UnityControllerFactory : DefaultControllerFactory { IUnityContainer container; public UnityControllerFactory(IUnityContainer container) {     this.container = container; } protected override IController GetControllerInstance(RequestContext reqContext, Type controllerType) {     IController controller;     if (controllerType == null)         throw new HttpException(                 404, String.Format(                     "The controller for path '{0}' could not be found" +     "or it does not implement IController.",                 reqContext.HttpContext.Request.Path));       if (!typeof(IController).IsAssignableFrom(controllerType))         throw new ArgumentException(                 string.Format(                     "Type requested is not a controller: {0}",                     controllerType.Name),                     "controllerType");     try     {         controller= container.Resolve(controllerType) as IController;     }     catch (Exception ex)     {         throw new InvalidOperationException(String.Format(                                 "Error resolving controller {0}",                                 controllerType.Name), ex);     }     return controller; }   }   Configure contract and concrete types in Unity Let’s configure our contract and concrete types in Unity for resolving our dependencies.   private void ConfigureUnity() {     //Create UnityContainer               IUnityContainer container = new UnityContainer()                 .RegisterType<IDatabaseFactory, DatabaseFactory>(new HttpContextLifetimeManager<IDatabaseFactory>())     .RegisterType<IUnitOfWork, UnitOfWork>(new HttpContextLifetimeManager<IUnitOfWork>())     .RegisterType<ICategoryRepository, CategoryRepository>(new HttpContextLifetimeManager<ICategoryRepository>());                 //Set container for Controller Factory                ControllerBuilder.Current.SetControllerFactory(             new UnityControllerFactory(container)); }   In the above ConfigureUnity method, we are registering our types onto Unity container with custom lifetime manager HttpContextLifetimeManager. Let’s call ConfigureUnity method in the Global.asax.cs for set controller factory for Unity and configuring the types with Unity.   protected void Application_Start() {     AreaRegistration.RegisterAllAreas();     RegisterGlobalFilters(GlobalFilters.Filters);     RegisterRoutes(RouteTable.Routes);     ConfigureUnity(); }   Developing web application using ASP.NET MVC 3 We have created our domain model for our web application and also have created repositories and configured dependencies with Unity container. Now we have to create controller classes and views for doing CRUD operations against the Category entity. Let’s create controller class for Category Category Controller   public class CategoryController : Controller {     private readonly ICategoryRepository categoryRepository;     private readonly IUnitOfWork unitOfWork;           public CategoryController(ICategoryRepository categoryRepository, IUnitOfWork unitOfWork)     {         this.categoryRepository = categoryRepository;         this.unitOfWork = unitOfWork;     }       public ActionResult Index()     {         var categories = categoryRepository.All();         return View(categories);     }     [HttpGet]     public ActionResult Edit(int id)     {         var category = categoryRepository.GetById(id);         return View(category);     }       [HttpPost]     public ActionResult Edit(int id, FormCollection collection)     {         var category = categoryRepository.GetById(id);         if (TryUpdateModel(category))         {             unitOfWork.Commit();             return RedirectToAction("Index");         }         else return View(category);                 }       [HttpGet]     public ActionResult Create()     {         var category = new Category();         return View(category);     }           [HttpPost]     public ActionResult Create(Category category)     {         if (!ModelState.IsValid)         {             return View("Create", category);         }                     categoryRepository.Add(category);         unitOfWork.Commit();         return RedirectToAction("Index");     }       [HttpPost]     public ActionResult Delete(int  id)     {         var category = categoryRepository.GetById(id);         categoryRepository.Delete(category);         unitOfWork.Commit();         var categories = categoryRepository.All();         return PartialView("CategoryList", categories);       }        }   Creating Views in Razor Now we are going to create views in Razor for our ASP.NET MVC 3 application.  Let’s create a partial view CategoryList.cshtml for listing category information and providing link for Edit and Delete operations. CategoryList.cshtml @using MyFinance.Helpers; @using MyFinance.Domain; @model IEnumerable<Category>      <table>         <tr>         <th>Actions</th>         <th>Name</th>          <th>Description</th>         </tr>     @foreach (var item in Model) {             <tr>             <td>                 @Html.ActionLink("Edit", "Edit",new { id = item.CategoryId })                 @Ajax.ActionLink("Delete", "Delete", new { id = item.CategoryId }, new AjaxOptions { Confirm = "Delete Expense?", HttpMethod = "Post", UpdateTargetId = "divCategoryList" })                           </td>             <td>                 @item.Name             </td>             <td>                 @item.Description             </td>         </tr>          }       </table>     <p>         @Html.ActionLink("Create New", "Create")     </p> The delete link is providing Ajax functionality using the Ajax.ActionLink. This will call an Ajax request for Delete action method in the CategoryCotroller class. In the Delete action method, it will return Partial View CategoryList after deleting the record. We are using CategoryList view for the Ajax functionality and also for Index view using for displaying list of category information. Let’s create Index view using partial view CategoryList  Index.chtml @model IEnumerable<MyFinance.Domain.Category> @{     ViewBag.Title = "Index"; }    <h2>Category List</h2>    <script src="@Url.Content("~/Scripts/jquery.unobtrusive-ajax.min.js")" type="text/javascript"></script>    <div id="divCategoryList">               @Html.Partial("CategoryList", Model) </div>   We can call the partial views using Html.Partial helper method. Now we are going to create View pages for insert and update functionality for the Category. Both view pages are sharing common user interface for entering the category information. So I want to create an EditorTemplate for the Category information. We have to create the EditorTemplate with the same name of entity object so that we can refer it on view pages using @Html.EditorFor(model => model) . So let’s create template with name Category. Let’s create view page for insert Category information   @model MyFinance.Domain.Category   @{     ViewBag.Title = "Save"; }   <h2>Create</h2>   <script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>   @using (Html.BeginForm()) {     @Html.ValidationSummary(true)     <fieldset>         <legend>Category</legend>                @Html.EditorFor(model => model)               <p>             <input type="submit" value="Create" />         </p>     </fieldset> }   <div>     @Html.ActionLink("Back to List", "Index") </div> ViewStart file In Razor views, we can add a file named _viewstart.cshtml in the views directory  and this will be shared among the all views with in the Views directory. The below code in the _viewstart.cshtml, sets the Layout page for every Views in the Views folder.      @{     Layout = "~/Views/Shared/_Layout.cshtml"; }   Source Code You can download the source code from http://efmvc.codeplex.com/ . The source will be refactored on over time.   Summary In this post, we have created a simple web application using ASP.NET MVC 3 and EF Code First. We have discussed on technologies and practices such as ASP.NET MVC 3, Razor, EF Code First, Unity 2, generic Repository and Unit of Work. In my later posts, I will modify the application and will be discussed on more things. Stay tuned to my blog  for more posts on step by step application building.

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  • Building services with .Net Part 1

    - by Allan Rwakatungu
    On the 26th of May 2010 , I made a presentation to the .NET user group meeting (thanks to Malisa Ncube for organizing this event every month … ). If you missed my presentation , we talked about why we should all be building services … better still using the .NET framework. This blog post is an introduction to services , why you would want to build services and how you can build services using the .NET framework. What is a service? OASIS defines service as "a mechanism to enable access to one or more capabilities, where the access is provided using a prescribed interface and is exercised consistent with constraints and policies as specified by the service description." [1]. If the above definition sounds to academic , you can also define a service as loosely coupled units of functionality that have no calls to each other embedded in the. Instead of services embedding calls to each other in their service code they use defined protocols that describe how services pass and parse messages. This is a good way to think about services if you’re from an objected oriented background. While in object oriented programming functions make calls to each other, in service oriented programming, functions pass messages between each other. Why would you want to use services? 1. If your enterprise architecture looks like this   Services are the building blocks for SOA . With SOA you can move away from the sphaggetti infrastructure that is common in most enterprises. The complexity or lack of visibility of the integration points in your enterprises makes it difficult and costly to implement new initiatives and changes into the business - and even impossible in some cases - as it is not possible to identify the impact a change in one system might have to other systems. With services you can move to an architecture like this Your building blocks from Spaghetti infrastructure to something that is more well-defined and manageable to achieve cost efficiency and not least business agility - enabling you to react to changes in the market with speed and achieve operational efficiency and control are services. 2. If you want to become the Gates or Zuckerburger. Have you heard about Web 2.0 ? Mashups? Software as a service (SAAS) ? Cloud computing ?   They all offer you the opportunity to have scalable but low cost business models and they built using services.  Some of my favorite companies that leverage services for their business models include  https://www.salesforce.com/ (cloud CRM) http://www. twitter.com (more people use twitter clients built by 3rd parties than their official clients) http://www.kayak.com/ (compares data from other travel sites to give information to users in one location) Services with the .NET framework      If you are a .NET developer and you want to develop services, Windows Communication Framework (WCF) is the tool for you. WCF is Microsoft’s unified programming model (service model) for building service oriented applications. ( Before .NET 3.0 you had several models for programming services in .NET including .NET remoting, Web services (ASMX), COM +, Microsoft Messaging queuing (MSMQ) etc, after .NET 3.0 the programming model was unified into one i.e. WCF ). Windows Communication Framework (WCF) provides you 1. An Software Development Kit (SDK) for creating SOA applications 2. A runtime for running services on the Windows platform Why should you use Windows Communication Foundation if you’re programming services?   1. It supports interoperable and open standards e.g. WS* protocols for programming SOAP services 2. It has a unified programming model. Whether you use TCP or Http or Pipes or transmitting using Messaging Queues, programmers need to learn just one way to program. Previously you had .NET remoting, MSMQ, Web services, COM+ and they were all done differently 3. Productive programming model You don’t have to worry about all the plumbing involved to write services. You have a rich declarative programming model to add stuff like logging, transactions, and reliable messages in-built in the Windows Communication Framework. Understanding services in WCF The basic principles of WCF are as easy as ABC A – Address This is where the service is located B- Binding This describes how you communicate with the service e.g. Use TCP, HTTP or both. How to exchange security information with the service etc. C – Contract This defines what the service can do. E.g. Pay water bill, Make a phone call A - Addresses In WCF, an address is a combination of transport, server name, port and path Example addresses may include http://localhost:8001 net.tcp://localhost:8002/MyService net.pipe://localhost/MyPipe net.msmq://localhost/private/MyService net.msmq://localhost/MyService B- Binding   There are numerous ways to communicate with services , different ways that a message can be formatted/sent/secured, that allows you to tailor your service for the compatibility/performance you require for your solution. Transport You can use HTTP TCP MSMQ , Named pipes, Your own custom transport etc Message You  can send a plain text binary, Message Transmission Optimization Mechanism (MTOM) message Communication security No security Transport security Message security Authenticating and authorizing callers etc Behaviour You service can support Transactions Be reliable Use queues Support ajax etc C - Contract You define what your service can do using Service contracts :- Define operations that your service can do, communications and behaviours Data contracts :- Define the messages that are passed from and into your service and how they are formatted Fault contracts :- Defines errors types in your service   As an example, suppose your service service shows money. You define your service contract using a interface [ServiceContract] public interface IShowMeTheMoney {   [OperationContract]    Money Show(); } You define the data contract by annotating a class it with the Data Contract attribute and fields you want to pass in the message as Data Members. (Note:- In the latest versions of WCF you dont have to use attributes if you passing all the objects properties in the message) [DataContract] public Money {   [DataMember]   public string Currency { get; set; }   [DataMember]   public Decimal Amount { get; set; }   public string Comment { get; set; } } Features of Windows Communication Foundation Windows Communication Foundation is not only simple but feature rich , offering you several options to tweak your service to fit your business requirements. Some of the features of WCF include 1. Workflow services You can combine WCF with Windows WorkFlow Foundation (WWF) to write workflow type services 2. Control how your data (messages) are transferred and serialized e.g. you can serialize your business objects as XML or binary 3. control over session management , instance creation and concurrency management without writing code if you like 4. Queues and reliable sessions. You can store messages from the sending client and later forward them to the receiving application. You can also guarantee that messages will arrive at their destincation. 5.Transactions:  You can have different services participate in a transaction operations that can be rolled back if needed 6. Security. WCF has rich features for authorization and authentication  as well as keep audit trails 7. Web programming model. WCF allows developers to expose services as non SOAP endpoints 8. Inbuilt features that you can use to write JSON and services that support AJAX applications And lots more In my next blog I will show you how you can use WCF features to write a real world business service.               Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 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-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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  • NoSQL with RavenDB and ASP.NET MVC - Part 2

    - by shiju
    In my previous post, we have discussed on how to work with RavenDB document database in an ASP.NET MVC application. We have setup RavenDB for our ASP.NET MVC application and did basic CRUD operations against a simple domain entity. In this post, let’s discuss on domain entity with deep object graph and how to query against RavenDB documents using Indexes.Let's create two domain entities for our demo ASP.NET MVC appplication  public class Category {       public string Id { get; set; }     [Required(ErrorMessage = "Name Required")]     [StringLength(25, ErrorMessage = "Must be less than 25 characters")]     public string Name { get; set;}     public string Description { get; set; }     public List<Expense> Expenses { get; set; }       public Category()     {         Expenses = new List<Expense>();     } }    public class Expense {       public string Id { get; set; }     public Category Category { get; set; }     public string  Transaction { get; set; }     public DateTime Date { get; set; }     public double Amount { get; set; }   }  We have two domain entities - Category and Expense. A single category contains a list of expense transactions and every expense transaction should have a Category.Let's create  ASP.NET MVC view model  for Expense transaction public class ExpenseViewModel {     public string Id { get; set; }       public string CategoryId { get; set; }       [Required(ErrorMessage = "Transaction Required")]            public string Transaction { get; set; }       [Required(ErrorMessage = "Date Required")]            public DateTime Date { get; set; }       [Required(ErrorMessage = "Amount Required")]     public double Amount { get; set; }       public IEnumerable<SelectListItem> Category { get; set; } } Let's create a contract type for Expense Repository  public interface IExpenseRepository {     Expense Load(string id);     IEnumerable<Expense> GetExpenseTransactions(DateTime startDate,DateTime endDate);     void Save(Expense expense,string categoryId);     void Delete(string id);  } Let's create a concrete type for Expense Repository for handling CRUD operations. public class ExpenseRepository : IExpenseRepository {   private IDocumentSession session; public ExpenseRepository() {         session = MvcApplication.CurrentSession; } public Expense Load(string id) {     return session.Load<Expense>(id); } public IEnumerable<Expense> GetExpenseTransactions(DateTime startDate, DateTime endDate) {             //Querying using the Index name "ExpenseTransactions"     //filtering with dates     var expenses = session.LuceneQuery<Expense>("ExpenseTransactions")         .WaitForNonStaleResults()         .Where(exp => exp.Date >= startDate && exp.Date <= endDate)         .ToArray();     return expenses; } public void Save(Expense expense,string categoryId) {     var category = session.Load<Category>(categoryId);     if (string.IsNullOrEmpty(expense.Id))     {         //new expense transaction         expense.Category = category;         session.Store(expense);     }     else     {         //modifying an existing expense transaction         var expenseToEdit = Load(expense.Id);         //Copy values to  expenseToEdit         ModelCopier.CopyModel(expense, expenseToEdit);         //set category object         expenseToEdit.Category = category;       }     //save changes     session.SaveChanges(); } public void Delete(string id) {     var expense = Load(id);     session.Delete<Expense>(expense);     session.SaveChanges(); }   }  Insert/Update Expense Transaction The Save method is used for both insert a new expense record and modifying an existing expense transaction. For a new expense transaction, we store the expense object with associated category into document session object and load the existing expense object and assign values to it for editing a existing record.  public void Save(Expense expense,string categoryId) {     var category = session.Load<Category>(categoryId);     if (string.IsNullOrEmpty(expense.Id))     {         //new expense transaction         expense.Category = category;         session.Store(expense);     }     else     {         //modifying an existing expense transaction         var expenseToEdit = Load(expense.Id);         //Copy values to  expenseToEdit         ModelCopier.CopyModel(expense, expenseToEdit);         //set category object         expenseToEdit.Category = category;       }     //save changes     session.SaveChanges(); } Querying Expense transactions   public IEnumerable<Expense> GetExpenseTransactions(DateTime startDate, DateTime endDate) {             //Querying using the Index name "ExpenseTransactions"     //filtering with dates     var expenses = session.LuceneQuery<Expense>("ExpenseTransactions")         .WaitForNonStaleResults()         .Where(exp => exp.Date >= startDate && exp.Date <= endDate)         .ToArray();     return expenses; }  The GetExpenseTransactions method returns expense transactions using a LINQ query expression with a Date comparison filter. The Lucene Query is using a index named "ExpenseTransactions" for getting the result set. In RavenDB, Indexes are LINQ queries stored in the RavenDB server and would be  executed on the background and will perform query against the JSON documents. Indexes will be working with a lucene query expression or a set operation. Indexes are composed using a Map and Reduce function. Check out Ayende's blog post on Map/Reduce We can create index using RavenDB web admin tool as well as programmitically using its Client API. The below shows the screen shot of creating index using web admin tool. We can also create Indexes using Raven Cleint API as shown in the following code documentStore.DatabaseCommands.PutIndex("ExpenseTransactions",     new IndexDefinition<Expense,Expense>() {     Map = Expenses => from exp in Expenses                     select new { exp.Date } });  In the Map function, we used a Linq expression as shown in the following from exp in docs.Expensesselect new { exp.Date };We have not used a Reduce function for the above index. A Reduce function is useful while performing aggregate functions based on the results from the Map function. Indexes can be use with set operations of RavenDB.SET OperationsUnlike other document databases, RavenDB supports set based operations that lets you to perform updates, deletes and inserts to the bulk_docs endpoint of RavenDB. For doing this, you just pass a query to a Index as shown in the following commandDELETE http://localhost:8080/bulk_docs/ExpenseTransactions?query=Date:20100531The above command using the Index named "ExpenseTransactions" for querying the documents with Date filter and  will delete all the documents that match the query criteria. The above command is equivalent of the following queryDELETE FROM ExpensesWHERE Date='2010-05-31' Controller & ActionsWe have created Expense Repository class for performing CRUD operations for the Expense transactions. Let's create a controller class for handling expense transactions.   public class ExpenseController : Controller { private ICategoryRepository categoyRepository; private IExpenseRepository expenseRepository; public ExpenseController(ICategoryRepository categoyRepository, IExpenseRepository expenseRepository) {     this.categoyRepository = categoyRepository;     this.expenseRepository = expenseRepository; } //Get Expense transactions based on dates public ActionResult Index(DateTime? StartDate, DateTime? EndDate) {     //If date is not passed, take current month's first and last dte     DateTime dtNow;     dtNow = DateTime.Today;     if (!StartDate.HasValue)     {         StartDate = new DateTime(dtNow.Year, dtNow.Month, 1);         EndDate = StartDate.Value.AddMonths(1).AddDays(-1);     }     //take last date of startdate's month, if endate is not passed     if (StartDate.HasValue && !EndDate.HasValue)     {         EndDate = (new DateTime(StartDate.Value.Year, StartDate.Value.Month, 1)).AddMonths(1).AddDays(-1);     }       var expenses = expenseRepository.GetExpenseTransactions(StartDate.Value, EndDate.Value);     if (Request.IsAjaxRequest())     {           return PartialView("ExpenseList", expenses);     }     ViewData.Add("StartDate", StartDate.Value.ToShortDateString());     ViewData.Add("EndDate", EndDate.Value.ToShortDateString());             return View(expenses);            }   // GET: /Expense/Edit public ActionResult Edit(string id) {       var expenseModel = new ExpenseViewModel();     var expense = expenseRepository.Load(id);     ModelCopier.CopyModel(expense, expenseModel);     var categories = categoyRepository.GetCategories();     expenseModel.Category = categories.ToSelectListItems(expense.Category.Id.ToString());                    return View("Save", expenseModel);          }   // // GET: /Expense/Create   public ActionResult Create() {     var expenseModel = new ExpenseViewModel();               var categories = categoyRepository.GetCategories();     expenseModel.Category = categories.ToSelectListItems("-1");     expenseModel.Date = DateTime.Today;     return View("Save", expenseModel); }   // // POST: /Expense/Save // Insert/Update Expense Tansaction [HttpPost] public ActionResult Save(ExpenseViewModel expenseViewModel) {     try     {         if (!ModelState.IsValid)         {               var categories = categoyRepository.GetCategories();                 expenseViewModel.Category = categories.ToSelectListItems(expenseViewModel.CategoryId);                               return View("Save", expenseViewModel);         }           var expense=new Expense();         ModelCopier.CopyModel(expenseViewModel, expense);          expenseRepository.Save(expense, expenseViewModel.CategoryId);                       return RedirectToAction("Index");     }     catch     {         return View();     } } //Delete a Expense Transaction public ActionResult Delete(string id) {     expenseRepository.Delete(id);     return RedirectToAction("Index");     }     }     Download the Source - You can download the source code from http://ravenmvc.codeplex.com

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  • Using a "white list" for extracting terms for Text Mining, Part 2

    - by [email protected]
    In my last post, we set the groundwork for extracting specific tokens from a white list using a CTXRULE index. In this post, we will populate a table with the extracted tokens and produce a case table suitable for clustering with Oracle Data Mining. Our corpus of documents will be stored in a database table that is defined as create table documents(id NUMBER, text VARCHAR2(4000)); However, any suitable Oracle Text-accepted data type can be used for the text. We then create a table to contain the extracted tokens. The id column contains the unique identifier (or case id) of the document. The token column contains the extracted token. Note that a given document many have many tokens, so there will be one row per token for a given document. create table extracted_tokens (id NUMBER, token VARCHAR2(4000)); The next step is to iterate over the documents and extract the matching tokens using the index and insert them into our token table. We use the MATCHES function for matching the query_string from my_thesaurus_rules with the text. DECLARE     cursor c2 is       select id, text       from documents; BEGIN     for r_c2 in c2 loop        insert into extracted_tokens          select r_c2.id id, main_term token          from my_thesaurus_rules          where matches(query_string,                        r_c2.text)>0;     end loop; END; Now that we have the tokens, we can compute the term frequency - inverse document frequency (TF-IDF) for each token of each document. create table extracted_tokens_tfidf as   with num_docs as (select count(distinct id) doc_cnt                     from extracted_tokens),        tf       as (select a.id, a.token,                            a.token_cnt/b.num_tokens token_freq                     from                        (select id, token, count(*) token_cnt                        from extracted_tokens                        group by id, token) a,                       (select id, count(*) num_tokens                        from extracted_tokens                        group by id) b                     where a.id=b.id),        doc_freq as (select token, count(*) overall_token_cnt                     from extracted_tokens                     group by token)   select tf.id, tf.token,          token_freq * ln(doc_cnt/df.overall_token_cnt) tf_idf   from num_docs,        tf,        doc_freq df   where df.token=tf.token; From the WITH clause, the num_docs query simply counts the number of documents in the corpus. The tf query computes the term (token) frequency by computing the number of times each token appears in a document and divides that by the number of tokens found in the document. The doc_req query counts the number of times the token appears overall in the corpus. In the SELECT clause, we compute the tf_idf. Next, we create the nested table required to produce one record per case, where a case corresponds to an individual document. Here, we COLLECT all the tokens for a given document into the nested column extracted_tokens_tfidf_1. CREATE TABLE extracted_tokens_tfidf_nt              NESTED TABLE extracted_tokens_tfidf_1                  STORE AS extracted_tokens_tfidf_tab AS              select id,                     cast(collect(DM_NESTED_NUMERICAL(token,tf_idf)) as DM_NESTED_NUMERICALS) extracted_tokens_tfidf_1              from extracted_tokens_tfidf              group by id;   To build the clustering model, we create a settings table and then insert the various settings. Most notable are the number of clusters (20), using cosine distance which is better for text, turning off auto data preparation since the values are ready for mining, the number of iterations (20) to get a better model, and the split criterion of size for clusters that are roughly balanced in number of cases assigned. CREATE TABLE km_settings (setting_name  VARCHAR2(30), setting_value VARCHAR2(30)); BEGIN  INSERT INTO km_settings (setting_name, setting_value) VALUES     VALUES (dbms_data_mining.clus_num_clusters, 20);  INSERT INTO km_settings (setting_name, setting_value)     VALUES (dbms_data_mining.kmns_distance, dbms_data_mining.kmns_cosine);   INSERT INTO km_settings (setting_name, setting_value) VALUES     VALUES (dbms_data_mining.prep_auto,dbms_data_mining.prep_auto_off);   INSERT INTO km_settings (setting_name, setting_value) VALUES     VALUES (dbms_data_mining.kmns_iterations,20);   INSERT INTO km_settings (setting_name, setting_value) VALUES     VALUES (dbms_data_mining.kmns_split_criterion,dbms_data_mining.kmns_size);   COMMIT; END; With this in place, we can now build the clustering model. BEGIN     DBMS_DATA_MINING.CREATE_MODEL(     model_name          => 'TEXT_CLUSTERING_MODEL',     mining_function     => dbms_data_mining.clustering,     data_table_name     => 'extracted_tokens_tfidf_nt',     case_id_column_name => 'id',     settings_table_name => 'km_settings'); END;To generate cluster names from this model, check out my earlier post on that topic.

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  • How To Clear An Alert - Part 2

    - by werner.de.gruyter
    There were some interesting comments and remarks on the original posting, so I decided to do a follow-up and address some of the issues that got raised... Handling Metric Errors First of all, there is a significant difference between an 'error' and an 'alert'. An 'alert' is the violation of a condition (a threshold) specified for a given metric. That means that the Agent is collecting and gathering the data for the metric, but there is a situation that requires the attention of an administrator. An 'error' on the other hand however, is a failure to collect metric data: The Agent is throwing the error because it cannot determine the value for the metric Whereas the 'alert' guarantees continuity of the metric data, an 'error' signals a big unknown. And the unknown aspect of all this is what makes an error a lot more serious than a regular alert: If you don't know what the current state of affairs is, there could be some serious issues brewing that nobody is aware of... The life-cycle of a Metric Error Clearing a metric error is pretty much the same workflow as a metric 'alert': The Agent signals the error after it failed to execute the metric The error is uploaded to the OMS/repository, where it becomes visible in the Console The error will remain active until the Agent is able to execute the metric successfully. Even though the metric is still getting scheduled and executed on a regular basis, the error will remain outstanding as long as the Agent is not capable of executing the metric correctly Knowing this, the way to fix the metric error should be obvious: Take the 'problem' away, and as soon as the metric is executed again (based on the frequency of the metric), the error will go away. The same tricks used to clear alerts can be used here too: Wait for the next scheduled execution. For those metrics that are executed regularly (like every 15 minutes or so), it's just a matter of waiting those minutes to see the updates. The 'Reevaluate Alert' button can be used to force a re-execution of the metric. In case a metric is executed once a day, this will be a better way to make sure that the underlying problem has been solved. And if it has been, the metric error will be removed, and the regular data points will be uploaded to the repository. And just in case you have to 'force' the issue a little: If you disable and re-enable a metric, it will get re-scheduled. And that means a new metric execution, and an update of the (hopefully) fixed problem. Database server-generated alerts and problem checkers There are various ways the Agent can collect metric data: Via a script or a SQL statement, reading a log file, getting a value from an SNMP OID or listening for SNMP traps or via the DBMS_SERVER_ALERTS mechanism of an Oracle database. For those alert which are generated by the database (like tablespace metrics for 10g and above databases), the Agent just 'waits' for the database to report any new findings. If the Agent has lost the current state of the server-side metrics (due to an incomplete recovery after a disaster, or after an improper use of the 'emctl clearstate' command), the Agent might be still aware of an alert that the database no longer has (or vice versa). The same goes for 'problem checker' alerts: Those metrics that only report data if there is a problem (like the 'invalid objects' metric) will also have a problem if the Agent state has been tampered with (again, the incomplete recovery, and after improper use of 'emctl clearstate' are the two main causes for this). The best way to deal with these kinds of mismatches, is to simple disable and re-enable the metric again: The disabling will clear the state of the metric, and the re-enabling will force a re-execution of the metric, so the new and updated results can get uploaded to the repository. Starting 10gR5, the Agent performs additional checks and verifications after each restart of the Agent and/or each state change of the database (shutdown/startup or failover in case of DataGuard) to catch these kinds of mismatches.

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  • Mapping Your Data with Bing Maps and SQL Server 2008 – Part 1

    Jonas Stawski takes you step by step through a sample project that demonstrates how to create an application that can get GeoSpatial coordinate data for addresses within a SQL Server database, and then use that data to locate those addresses on a Bing Map on a website as pushpins, either grouped or ungrouped: And there is full source-code too, in the speech-bubble.

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  • What's up with LDoms: Part 4 - Virtual Networking Explained

    - by Stefan Hinker
    I'm back from my summer break (and some pressing business that kept me away from this), ready to continue with Oracle VM Server for SPARC ;-) In this article, we'll have a closer look at virtual networking.  Basic connectivity as we've seen it in the first, simple example, is easy enough.  But there are numerous options for the virtual switches and virtual network ports, which we will discuss in more detail now.   In this section, we will concentrate on virtual networking - the capabilities of virtual switches and virtual network ports - only.  Other options involving hardware assignment or redundancy will be covered in separate sections later on. There are two basic components involved in virtual networking for LDoms: Virtual switches and virtual network devices.  The virtual switch should be seen just like a real ethernet switch.  It "runs" in the service domain and moves ethernet packets back and forth.  A virtual network device is plumbed in the guest domain.  It corresponds to a physical network device in the real world.  There, you'd be plugging a cable into the network port, and plug the other end of that cable into a switch.  In the virtual world, you do the same:  You create a virtual network device for your guest and connect it to a virtual switch in a service domain.  The result works just like in the physical world, the network device sends and receives ethernet packets, and the switch does all those things ethernet switches tend to do. If you look at the reference manual of Oracle VM Server for SPARC, there are numerous options for virtual switches and network devices.  Don't be confused, it's rather straight forward, really.  Let's start with the simple case, and work our way to some more sophisticated options later on.  In many cases, you'll want to have several guests that communicate with the outside world on the same ethernet segment.  In the real world, you'd connect each of these systems to the same ethernet switch.  So, let's do the same thing in the virtual world: root@sun # ldm add-vsw net-dev=nxge2 admin-vsw primary root@sun # ldm add-vnet admin-net admin-vsw mars root@sun # ldm add-vnet admin-net admin-vsw venus We've just created a virtual switch called "admin-vsw" and connected it to the physical device nxge2.  In the physical world, we'd have powered up our ethernet switch and installed a cable between it and our big enterprise datacenter switch.  We then created a virtual network interface for each one of the two guest systems "mars" and "venus" and connected both to that virtual switch.  They can now communicate with each other and with any system reachable via nxge2.  If primary were running Solaris 10, communication with the guests would not be possible.  This is different with Solaris 11, please see the Admin Guide for details.  Note that I've given both the vswitch and the vnet devices some sensible names, something I always recommend. Unless told otherwise, the LDoms Manager software will automatically assign MAC addresses to all network elements that need one.  It will also make sure that these MAC addresses are unique and reuse MAC addresses to play nice with all those friendly DHCP servers out there.  However, if we want to do this manually, we can also do that.  (One reason might be firewall rules that work on MAC addresses.)  So let's give mars a manually assigned MAC address: root@sun # ldm set-vnet mac-addr=0:14:4f:f9:c4:13 admin-net mars Within the guest, these virtual network devices have their own device driver.  In Solaris 10, they'd appear as "vnet0".  Solaris 11 would apply it's usual vanity naming scheme.  We can configure these interfaces just like any normal interface, give it an IP-address and configure sophisticated routing rules, just like on bare metal.  In many cases, using Jumbo Frames helps increase throughput performance.  By default, these interfaces will run with the standard ethernet MTU of 1500 bytes.  To change this,  it is usually sufficient to set the desired MTU for the virtual switch.  This will automatically set the same MTU for all vnet devices attached to that switch.  Let's change the MTU size of our admin-vsw from the example above: root@sun # ldm set-vsw mtu=9000 admin-vsw primary Note that that you can set the MTU to any value between 1500 and 16000.  Of course, whatever you set needs to be supported by the physical network, too. Another very common area of network configuration is VLAN tagging. This can be a little confusing - my advise here is to be very clear on what you want, and perhaps draw a little diagram the first few times.  As always, keeping a configuration simple will help avoid errors of all kind.  Nevertheless, VLAN tagging is very usefull to consolidate different networks onto one physical cable.  And as such, this concept needs to be carried over into the virtual world.  Enough of the introduction, here's a little diagram to help in explaining how VLANs work in LDoms: Let's remember that any VLANs not explicitly tagged have the default VLAN ID of 1. In this example, we have a vswitch connected to a physical network that carries untagged traffic (VLAN ID 1) as well as VLANs 11, 22, 33 and 44.  There might also be other VLANs on the wire, but the vswitch will ignore all those packets.  We also have two vnet devices, one for mars and one for venus.  Venus will see traffic from VLANs 33 and 44 only.  For VLAN 44, venus will need to configure a tagged interface "vnet44000".  For VLAN 33, the vswitch will untag all incoming traffic for venus, so that venus will see this as "normal" or untagged ethernet traffic.  This is very useful to simplify guest configuration and also allows venus to perform Jumpstart or AI installations over this network even if the Jumpstart or AI server is connected via VLAN 33.  Mars, on the other hand, has full access to untagged traffic from the outside world, and also to VLANs 11,22 and 33, but not 44.  On the command line, we'd do this like this: root@sun # ldm add-vsw net-dev=nxge2 pvid=1 vid=11,22,33,44 admin-vsw primary root@sun # ldm add-vnet admin-net pvid=1 vid=11,22,33 admin-vsw mars root@sun # ldm add-vnet admin-net pvid=33 vid=44 admin-vsw venus Finally, I'd like to point to a neat little option that will make your live easier in all those cases where configurations tend to change over the live of a guest system.  It's the "id=<somenumber>" option available for both vswitches and vnet devices.  Normally, Solaris in the guest would enumerate network devices sequentially.  However, it has ways of remembering this initial numbering.  This is good in the physical world.  In the virtual world, whenever you unbind (aka power off and disassemble) a guest system, remove and/or add network devices and bind the system again, chances are this numbering will change.  Configuration confusion will follow suit.  To avoid this, nail down the initial numbering by assigning each vnet device it's device-id explicitly: root@sun # ldm add-vnet admin-net id=1 admin-vsw venus Please consult the Admin Guide for details on this, and how to decipher these network ids from Solaris running in the guest. Thanks for reading this far.  Links for further reading are essentially only the Admin Guide and Reference Manual and can be found above.  I hope this is useful and, as always, I welcome any comments.

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  • Launching a WPF Window in a Separate Thread, Part 1

    - by Reed
    Typically, I strongly recommend keeping the user interface within an application’s main thread, and using multiple threads to move the actual “work” into background threads.  However, there are rare times when creating a separate, dedicated thread for a Window can be beneficial.  This is even acknowledged in the MSDN samples, such as the Multiple Windows, Multiple Threads sample.  However, doing this correctly is difficult.  Even the referenced MSDN sample has major flaws, and will fail horribly in certain scenarios.  To ease this, I wrote a small class that alleviates some of the difficulties involved. The MSDN Multiple Windows, Multiple Threads Sample shows how to launch a new thread with a WPF Window, and will work in most cases.  The sample code (commented and slightly modified) works out to the following: // Create a thread Thread newWindowThread = new Thread(new ThreadStart( () => { // Create and show the Window Window1 tempWindow = new Window1(); tempWindow.Show(); // Start the Dispatcher Processing System.Windows.Threading.Dispatcher.Run(); })); // Set the apartment state newWindowThread.SetApartmentState(ApartmentState.STA); // Make the thread a background thread newWindowThread.IsBackground = true; // Start the thread newWindowThread.Start(); .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; } This sample creates a thread, marks it as single threaded apartment state, and starts the Dispatcher on that thread. That is the minimum requirements to get a Window displaying and handling messages correctly, but, unfortunately, has some serious flaws. The first issue – the created thread will run continuously until the application shuts down, given the code in the sample.  The problem is that the ThreadStart delegate used ends with running the Dispatcher.  However, nothing ever stops the Dispatcher processing.  The thread was created as a Background thread, which prevents it from keeping the application alive, but the Dispatcher will continue to pump dispatcher frames until the application shuts down. In order to fix this, we need to call Dispatcher.InvokeShutdown after the Window is closed.  This would require modifying the above sample to subscribe to the Window’s Closed event, and, at that point, shutdown the Dispatcher: // Create a thread Thread newWindowThread = new Thread(new ThreadStart( () => { Window1 tempWindow = new Window1(); // When the window closes, shut down the dispatcher tempWindow.Closed += (s,e) => Dispatcher.CurrentDispatcher.BeginInvokeShutdown(DispatcherPriority.Background); tempWindow.Show(); // Start the Dispatcher Processing System.Windows.Threading.Dispatcher.Run(); })); // Setup and start thread as before This eliminates the first issue.  Now, when the Window is closed, the new thread’s Dispatcher will shut itself down, which in turn will cause the thread to complete. The above code will work correctly for most situations.  However, there is still a potential problem which could arise depending on the content of the Window1 class.  This is particularly nasty, as the code could easily work for most windows, but fail on others. The problem is, at the point where the Window is constructed, there is no active SynchronizationContext.  This is unlikely to be a problem in most cases, but is an absolute requirement if there is code within the constructor of Window1 which relies on a context being in place. While this sounds like an edge case, it’s fairly common.  For example, if a BackgroundWorker is started within the constructor, or a TaskScheduler is built using TaskScheduler.FromCurrentSynchronizationContext() with the expectation of synchronizing work to the UI thread, an exception will be raised at some point.  Both of these classes rely on the existence of a proper context being installed to SynchronizationContext.Current, which happens automatically, but not until Dispatcher.Run is called.  In the above case, SynchronizationContext.Current will return null during the Window’s construction, which can cause exceptions to occur or unexpected behavior. Luckily, this is fairly easy to correct.  We need to do three things, in order, prior to creating our Window: Create and initialize the Dispatcher for the new thread manually Create a synchronization context for the thread which uses the Dispatcher Install the synchronization context Creating the Dispatcher is quite simple – The Dispatcher.CurrentDispatcher property gets the current thread’s Dispatcher and “creates a new Dispatcher if one is not already associated with the thread.”  Once we have the correct Dispatcher, we can create a SynchronizationContext which uses the dispatcher by creating a DispatcherSynchronizationContext.  Finally, this synchronization context can be installed as the current thread’s context via SynchronizationContext.SetSynchronizationContext.  These three steps can easily be added to the above via a single line of code: // Create a thread Thread newWindowThread = new Thread(new ThreadStart( () => { // Create our context, and install it: SynchronizationContext.SetSynchronizationContext( new DispatcherSynchronizationContext( Dispatcher.CurrentDispatcher)); Window1 tempWindow = new Window1(); // When the window closes, shut down the dispatcher tempWindow.Closed += (s,e) => Dispatcher.CurrentDispatcher.BeginInvokeShutdown(DispatcherPriority.Background); tempWindow.Show(); // Start the Dispatcher Processing System.Windows.Threading.Dispatcher.Run(); })); // Setup and start thread as before This now forces the synchronization context to be in place before the Window is created and correctly shuts down the Dispatcher when the window closes. However, there are quite a few steps.  In my next post, I’ll show how to make this operation more reusable by creating a class with a far simpler API…

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