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• Selector for a range of ids

  - by Kiffin

  I need to select all span tag elements within a div with an id list_{[0-9]}+ having the following form: <div id="list_1234" ...> <!-- can be nested multiple levels deep --> ... <span class="list_span">Hello</span> </div> How can I do that, e.g. without using jQuery? Is that possible?

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• Recommended way to set up xcconfig files

  - by LK

  Is there any best recommended way for setting up xcconfig files? Where does the projects related fields go and where do target related go? What about multiple targets?

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• redefinition c++

  - by coubeatczech

  hi, how does header including in c++ work? I have the classes already implemented in .h file and when there is #include in two files, there's this error: files.h:14:7: error: redefinition of ‘class abstract_file’ files.h:14:20: error: previous definition of ‘class abstract_file’ multiple times for each class and enum. Can anyone explain this?

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• can I duplicate my nodes in Drupal ? (to later slightly change them)

  - by Patrick

  can I duplicate my nodes in Drupal ? (to later slightly change them) My customer needs to add several nodes with same content (except for one image) and he would prefer to not have to fill the same content multiple times for each similar node. thanks

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• Will AJAX cause my site to have a high bounce % and hurt my search ratings?

  - by Cryo

  I'm building an art gallery website that updates its images via AJAX, for those who have javascript enabled, rather than request multiple page loads. I assume this will appear as though my site has a high bounce percentage. I understand that search engines will not be able to index dynamic content, but will such a misinterpreted bounce rate hurt my search engine ratings, even if I have many return visitors?

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• DocumentCompleted event when the page is fully loaded in WebBrowser form (Windows Forms C#)

  - by Tolga E

  I use the DocumentCompleted but this gets fired multiple times. Now I've seen this example if (e.Url.AbsolutePath != this.webBrowser.Url.AbsolutePath) which is used to confirm that the requested file is completed loading but this gets fired before anything else (like images) on the page is loaded. Thus I'm still not able to tell when a webpage is fully loaded. Is there a way to ensure that the webpage has fully loaded and there's nothing being loaded?

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• How to create many div's with 100% height?

  - by ChrisBenyamin

  I need a html document, that contains multiple div's with 100% height (screen filling) one below the other. I have tried to apply every element a height of 100%, but that won't work seamless nor clean. Maybe there is a option with JavaScript? I don't have an idea. Please suggest me your solutions. chris

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• Security in OBIEE 11g, Part 2

  - by Rob Reynolds

  Continuing the series on OBIEE 11g, our guest blogger this week is Pravin Janardanam. Here is Part 2 of his overview of Security in OBIEE 11g. OBIEE 11g Security Overview, Part 2 by Pravin Janardanam In my previous blog on Security, I discussed the OBIEE 11g changes regarding Authentication mechanism, RPD protection and encryption. This blog will include a discussion about OBIEE 11g Authorization and other Security aspects. Authorization: Authorization in 10g was achieved using a combination of Users, Groups and association of privileges and object permissions to users and Groups. Two keys changes to Authorization in OBIEE 11g are: Application Roles Policies / Permission Groups Application Roles are introduced in OBIEE 11g. An application role is specific to the application. They can be mapped to other application roles defined in the same application scope and also to enterprise users or groups, and they are used in authorization decisions. Application roles in 11g take the place of Groups in 10g within OBIEE application. In OBIEE 10g, any changes to corporate LDAP groups require a corresponding change to Groups and their permission assignment. In OBIEE 11g, Application roles provide insulation between permission definitions and corporate LDAP Groups. Permissions are defined at Application Role level and changes to LDAP groups just require a reassignment of the Group to the Application Roles. Permissions and privileges are assigned to Application Roles and users in OBIEE 11g compared to Groups and Users in 10g. The diagram below shows the relationship between users, groups and application roles. Note that the Groups shown in the diagram refer to LDAP Groups (WebLogic Groups by default) and not OBIEE application Groups. The following screenshot compares the permission windows from Admin tool in 10g vs 11g. Note that the Groups in the OBIEE 10g are replaced with Application Roles in OBIEE 11g. The same is applicable to OBIEE web catalog objects.    The default Application Roles available after OBIEE 11g installation are BIAdministrator, BISystem, BIConsumer and BIAuthor. Application policies are the authorization policies that an application relies upon for controlling access to its resources. An Application Role is defined by the Application Policy. The following screenshot shows the policies defined for BIAdministrator and BISystem Roles. Note that the permission for impersonation is granted to BISystem Role. In OBIEE 10g, the permission to manage repositories and Impersonation were assigned to “Administrators” group with no control to separate these permissions in the Administrators group. Hence user “Administrator” also had the permission to impersonate. In OBI11g, BIAdministrator does not have the permission to impersonate. This gives more flexibility to have multiple users perform different administrative functions. Application Roles, Policies, association of Policies to application roles and association of users and groups to application roles are managed using Fusion Middleware Enterprise Manager (FMW EM). They reside in the policy store, identified by the system-jazn-data.xml file. The screenshots below show where they are created and managed in FMW EM. The following screenshot shows the assignment of WebLogic Groups to Application Roles. The following screenshot shows the assignment of Permissions to Application Roles (Application Policies). Note: Object level permission association to Applications Roles resides in the RPD for repository objects. Permissions and Privilege for web catalog objects resides in the OBIEE Web Catalog. Wherever Groups were used in the web catalog and RPD has been replaced with Application roles in OBIEE 11g. Following are the tools used in OBIEE 11g Security Administration: ·       Users and Groups are managed in Oracle WebLogic Administration console (by default). If WebLogic is integrated with other LDAP products, then Users and Groups needs to managed using the interface provide by the respective LDAP vendor – New in OBIEE 11g ·       Application Roles and Application Policies are managed in Oracle Enterprise Manager - Fusion Middleware Control – New in OBIEE 11g ·       Repository object permissions are managed in OBIEE Administration tool – Same as 10g but the assignment is to Application Roles instead of Groups ·       Presentation Services Catalog Permissions and Privileges are managed in OBI Application administration page - Same as 10g but the assignment is to Application Roles instead of Groups Credential Store: Credential Store is a single consolidated service provider to store and manage the application credentials securely. The credential store contains credentials that either user supplied or system generated. Credential store in OBIEE 10g is file based and is managed using cryptotools utility. In 11g, Credential store can be managed directly from the FMW Enterprise Manager and is stored in cwallet.sso file. By default, the Credential Store stores password for deployed RPDs, BI Publisher data sources and BISystem user. In addition, Credential store can be LDAP based but only Oracle Internet Directory is supported right now. As you can see OBIEE security is integrated with Oracle Fusion Middleware security architecture. This provides a common security framework for all components of Business Intelligence and Fusion Middleware applications.

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• Capturing and Transforming ASP.NET Output with Response.Filter

  - by Rick Strahl

  During one of my Handlers and Modules session at DevConnections this week one of the attendees asked a question that I didn’t have an immediate answer for. Basically he wanted to capture response output completely and then apply some filtering to the output – effectively injecting some additional content into the page AFTER the page had completely rendered. Specifically the output should be captured from anywhere – not just a page and have this code injected into the page. Some time ago I posted some code that allows you to capture ASP.NET Page output by overriding the Render() method, capturing the HtmlTextWriter() and reading its content, modifying the rendered data as text then writing it back out. I’ve actually used this approach on a few occasions and it works fine for ASP.NET pages. But this obviously won’t work outside of the Page class environment and it’s not really generic – you have to create a custom page class in order to handle the output capture. [updated 11/16/2009 – updated ResponseFilterStream implementation and a few additional notes based on comments] Enter Response.Filter However, ASP.NET includes a Response.Filter which can be used – well to filter output. Basically Response.Filter is a stream through which the OutputStream is piped back to the Web Server (indirectly). As content is written into the Response object, the filter stream receives the appropriate Stream commands like Write, Flush and Close as well as read operations although for a Response.Filter that’s uncommon to be hit. The Response.Filter can be programmatically replaced at runtime which allows you to effectively intercept all output generation that runs through ASP.NET. A common Example: Dynamic GZip Encoding A rather common use of Response.Filter hooking up code based, dynamic  GZip compression for requests which is dead simple by applying a GZipStream (or DeflateStream) to Response.Filter. The following generic routines can be used very easily to detect GZip capability of the client and compress response output with a single line of code and a couple of library helper routines: WebUtils.GZipEncodePage(); which is handled with a few lines of reusable code and a couple of static helper methods: /// <summary> ///Sets up the current page or handler to use GZip through a Response.Filter ///IMPORTANT:  ///You have to call this method before any output is generated! /// </summary> public static void GZipEncodePage() {     HttpResponse Response = HttpContext.Current.Response;     if(IsGZipSupported())     {         stringAcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"];         if(AcceptEncoding.Contains("deflate"))         {             Response.Filter = newSystem.IO.Compression.DeflateStream(Response.Filter,                                        System.IO.Compression.CompressionMode.Compress);             Response.AppendHeader("Content-Encoding", "deflate");         }         else        {             Response.Filter = newSystem.IO.Compression.GZipStream(Response.Filter,                                       System.IO.Compression.CompressionMode.Compress);             Response.AppendHeader("Content-Encoding", "gzip");                            }     }     // Allow proxy servers to cache encoded and unencoded versions separately    Response.AppendHeader("Vary", "Content-Encoding"); } /// <summary> /// Determines if GZip is supported /// </summary> /// <returns></returns> public static bool IsGZipSupported() { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (!string.IsNullOrEmpty(AcceptEncoding) && (AcceptEncoding.Contains("gzip") || AcceptEncoding.Contains("deflate"))) return true; return false; } GZipStream and DeflateStream are streams that are assigned to Response.Filter and by doing so apply the appropriate compression on the active Response. Response.Filter content is chunked So to implement a Response.Filter effectively requires only that you implement a custom stream and handle the Write() method to capture Response output as it’s written. At first blush this seems very simple – you capture the output in Write, transform it and write out the transformed content in one pass. And that indeed works for small amounts of content. But you see, the problem is that output is written in small buffer chunks (a little less than 16k it appears) rather than just a single Write() statement into the stream, which makes perfect sense for ASP.NET to stream data back to IIS in smaller chunks to minimize memory usage en route. Unfortunately this also makes it a more difficult to implement any filtering routines since you don’t directly get access to all of the response content which is problematic especially if those filtering routines require you to look at the ENTIRE response in order to transform or capture the output as is needed for the solution the gentleman in my session asked for. So in order to address this a slightly different approach is required that basically captures all the Write() buffers passed into a cached stream and then making the stream available only when it’s complete and ready to be flushed. As I was thinking about the implementation I also started thinking about the few instances when I’ve used Response.Filter implementations. Each time I had to create a new Stream subclass and create my custom functionality but in the end each implementation did the same thing – capturing output and transforming it. I thought there should be an easier way to do this by creating a re-usable Stream class that can handle stream transformations that are common to Response.Filter implementations. Creating a semi-generic Response Filter Stream Class What I ended up with is a ResponseFilterStream class that provides a handful of Events that allow you to capture and/or transform Response content. The class implements a subclass of Stream and then overrides Write() and Flush() to handle capturing and transformation operations. By exposing events it’s easy to hook up capture or transformation operations via single focused methods. ResponseFilterStream exposes the following events: CaptureStream, CaptureString Captures the output only and provides either a MemoryStream or String with the final page output. Capture is hooked to the Flush() operation of the stream. TransformStream, TransformString Allows you to transform the complete response output with events that receive a MemoryStream or String respectively and can you modify the output then return it back as a return value. The transformed output is then written back out in a single chunk to the response output stream. These events capture all output internally first then write the entire buffer into the response. TransformWrite, TransformWriteString Allows you to transform the Response data as it is written in its original chunk size in the Stream’s Write() method. Unlike TransformStream/TransformString which operate on the complete output, these events only see the current chunk of data written. This is more efficient as there’s no caching involved, but can cause problems due to searched content splitting over multiple chunks. Using this implementation, creating a custom Response.Filter transformation becomes as simple as the following code. To hook up the Response.Filter using the MemoryStream version event: ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformStream += filter_TransformStream; Response.Filter = filter; and the event handler to do the transformation: MemoryStream filter_TransformStream(MemoryStream ms) { Encoding encoding = HttpContext.Current.Response.ContentEncoding; string output = encoding.GetString(ms.ToArray()); output = FixPaths(output); ms = new MemoryStream(output.Length); byte[] buffer = encoding.GetBytes(output); ms.Write(buffer,0,buffer.Length); return ms; } private string FixPaths(string output) { string path = HttpContext.Current.Request.ApplicationPath; // override root path wonkiness if (path == "/") path = ""; output = output.Replace("\"~/", "\"" + path + "/").Replace("'~/", "'" + path + "/"); return output; } The idea of the event handler is that you can do whatever you want to the stream and return back a stream – either the same one that’s been modified or a brand new one – which is then sent back to as the final response. The above code can be simplified even more by using the string version events which handle the stream to string conversions for you: ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformString += filter_TransformString; Response.Filter = filter; and the event handler to do the transformation calling the same FixPaths method shown above: string filter_TransformString(string output) { return FixPaths(output); } The events for capturing output and capturing and transforming chunks work in a very similar way. By using events to handle the transformations ResponseFilterStream becomes a reusable component and we don’t have to create a new stream class or subclass an existing Stream based classed. By the way, the example used here is kind of a cool trick which transforms “~/” expressions inside of the final generated HTML output – even in plain HTML controls not HTML controls – and transforms them into the appropriate application relative path in the same way that ResolveUrl would do. So you can write plain old HTML like this: <a href=”~/default.aspx”>Home</a>  and have it turned into: <a href=”/myVirtual/default.aspx”>Home</a>  without having to use an ASP.NET control like Hyperlink or Image or having to constantly use: <img src=”<%= ResolveUrl(“~/images/home.gif”) %>” /> in MVC applications (which frankly is one of the most annoying things about MVC especially given the path hell that extension-less and endpoint-less URLs impose). I can’t take credit for this idea. While discussing the Response.Filter issues on Twitter a hint from Dylan Beattie who pointed me at one of his examples which does something similar. I thought the idea was cool enough to use an example for future demos of Response.Filter functionality in ASP.NET next I time I do the Modules and Handlers talk (which was great fun BTW). How practical this is is debatable however since there’s definitely some overhead to using a Response.Filter in general and especially on one that caches the output and the re-writes it later. Make sure to test for performance anytime you use Response.Filter hookup and make sure it' doesn’t end up killing perf on you. You’ve been warned :-}. How does ResponseFilterStream work? The big win of this implementation IMHO is that it’s a reusable  component – so for implementation there’s no new class, no subclassing – you simply attach to an event to implement an event handler method with a straight forward signature to retrieve the stream or string you’re interested in. The implementation is based on a subclass of Stream as is required in order to handle the Response.Filter requirements. What’s different than other implementations I’ve seen in various places is that it supports capturing output as a whole to allow retrieving the full response output for capture or modification. The exception are the TransformWrite and TransformWrite events which operate only active chunk of data written by the Response. For captured output, the Write() method captures output into an internal MemoryStream that is cached until writing is complete. So Write() is called when ASP.NET writes to the Response stream, but the filter doesn’t pass on the Write immediately to the filter’s internal stream. The data is cached and only when the Flush() method is called to finalize the Stream’s output do we actually send the cached stream off for transformation (if the events are hooked up) and THEN finally write out the returned content in one big chunk. Here’s the implementation of ResponseFilterStream: /// <summary> /// A semi-generic Stream implementation for Response.Filter with /// an event interface for handling Content transformations via /// Stream or String. /// <remarks> /// Use with care for large output as this implementation copies /// the output into a memory stream and so increases memory usage. /// </remarks> /// </summary> public class ResponseFilterStream : Stream { /// <summary> /// The original stream /// </summary> Stream _stream; /// <summary> /// Current position in the original stream /// </summary> long _position; /// <summary> /// Stream that original content is read into /// and then passed to TransformStream function /// </summary> MemoryStream _cacheStream = new MemoryStream(5000); /// <summary> /// Internal pointer that that keeps track of the size /// of the cacheStream /// </summary> int _cachePointer = 0; /// <summary> /// /// </summary> /// <param name="responseStream"></param> public ResponseFilterStream(Stream responseStream) { _stream = responseStream; } /// <summary> /// Determines whether the stream is captured /// </summary> private bool IsCaptured { get { if (CaptureStream != null || CaptureString != null || TransformStream != null || TransformString != null) return true; return false; } } /// <summary> /// Determines whether the Write method is outputting data immediately /// or delaying output until Flush() is fired. /// </summary> private bool IsOutputDelayed { get { if (TransformStream != null || TransformString != null) return true; return false; } } /// <summary> /// Event that captures Response output and makes it available /// as a MemoryStream instance. Output is captured but won't /// affect Response output. /// </summary> public event Action<MemoryStream> CaptureStream; /// <summary> /// Event that captures Response output and makes it available /// as a string. Output is captured but won't affect Response output. /// </summary> public event Action<string> CaptureString; /// <summary> /// Event that allows you transform the stream as each chunk of /// the output is written in the Write() operation of the stream. /// This means that that it's possible/likely that the input /// buffer will not contain the full response output but only /// one of potentially many chunks. /// /// This event is called as part of the filter stream's Write() /// operation. /// </summary> public event Func<byte[], byte[]> TransformWrite; /// <summary> /// Event that allows you to transform the response stream as /// each chunk of bytep[] output is written during the stream's write /// operation. This means it's possibly/likely that the string /// passed to the handler only contains a portion of the full /// output. Typical buffer chunks are around 16k a piece. /// /// This event is called as part of the stream's Write operation. /// </summary> public event Func<string, string> TransformWriteString; /// <summary> /// This event allows capturing and transformation of the entire /// output stream by caching all write operations and delaying final /// response output until Flush() is called on the stream. /// </summary> public event Func<MemoryStream, MemoryStream> TransformStream; /// <summary> /// Event that can be hooked up to handle Response.Filter /// Transformation. Passed a string that you can modify and /// return back as a return value. The modified content /// will become the final output. /// </summary> public event Func<string, string> TransformString; protected virtual void OnCaptureStream(MemoryStream ms) { if (CaptureStream != null) CaptureStream(ms); } private void OnCaptureStringInternal(MemoryStream ms) { if (CaptureString != null) { string content = HttpContext.Current.Response.ContentEncoding.GetString(ms.ToArray()); OnCaptureString(content); } } protected virtual void OnCaptureString(string output) { if (CaptureString != null) CaptureString(output); } protected virtual byte[] OnTransformWrite(byte[] buffer) { if (TransformWrite != null) return TransformWrite(buffer); return buffer; } private byte[] OnTransformWriteStringInternal(byte[] buffer) { Encoding encoding = HttpContext.Current.Response.ContentEncoding; string output = OnTransformWriteString(encoding.GetString(buffer)); return encoding.GetBytes(output); } private string OnTransformWriteString(string value) { if (TransformWriteString != null) return TransformWriteString(value); return value; } protected virtual MemoryStream OnTransformCompleteStream(MemoryStream ms) { if (TransformStream != null) return TransformStream(ms); return ms; } /// <summary> /// Allows transforming of strings /// /// Note this handler is internal and not meant to be overridden /// as the TransformString Event has to be hooked up in order /// for this handler to even fire to avoid the overhead of string /// conversion on every pass through. /// </summary> /// <param name="responseText"></param> /// <returns></returns> private string OnTransformCompleteString(string responseText) { if (TransformString != null) TransformString(responseText); return responseText; } /// <summary> /// Wrapper method form OnTransformString that handles /// stream to string and vice versa conversions /// </summary> /// <param name="ms"></param> /// <returns></returns> internal MemoryStream OnTransformCompleteStringInternal(MemoryStream ms) { if (TransformString == null) return ms; //string content = ms.GetAsString(); string content = HttpContext.Current.Response.ContentEncoding.GetString(ms.ToArray()); content = TransformString(content); byte[] buffer = HttpContext.Current.Response.ContentEncoding.GetBytes(content); ms = new MemoryStream(); ms.Write(buffer, 0, buffer.Length); //ms.WriteString(content); return ms; } /// <summary> /// /// </summary> public override bool CanRead { get { return true; } } public override bool CanSeek { get { return true; } } /// <summary> /// /// </summary> public override bool CanWrite { get { return true; } } /// <summary> /// /// </summary> public override long Length { get { return 0; } } /// <summary> /// /// </summary> public override long Position { get { return _position; } set { _position = value; } } /// <summary> /// /// </summary> /// <param name="offset"></param> /// <param name="direction"></param> /// <returns></returns> public override long Seek(long offset, System.IO.SeekOrigin direction) { return _stream.Seek(offset, direction); } /// <summary> /// /// </summary> /// <param name="length"></param> public override void SetLength(long length) { _stream.SetLength(length); } /// <summary> /// /// </summary> public override void Close() { _stream.Close(); } /// <summary> /// Override flush by writing out the cached stream data /// </summary> public override void Flush() { if (IsCaptured && _cacheStream.Length > 0) { // Check for transform implementations _cacheStream = OnTransformCompleteStream(_cacheStream); _cacheStream = OnTransformCompleteStringInternal(_cacheStream); OnCaptureStream(_cacheStream); OnCaptureStringInternal(_cacheStream); // write the stream back out if output was delayed if (IsOutputDelayed) _stream.Write(_cacheStream.ToArray(), 0, (int)_cacheStream.Length); // Clear the cache once we've written it out _cacheStream.SetLength(0); } // default flush behavior _stream.Flush(); } /// <summary> /// /// </summary> /// <param name="buffer"></param> /// <param name="offset"></param> /// <param name="count"></param> /// <returns></returns> public override int Read(byte[] buffer, int offset, int count) { return _stream.Read(buffer, offset, count); } /// <summary> /// Overriden to capture output written by ASP.NET and captured /// into a cached stream that is written out later when Flush() /// is called. /// </summary> /// <param name="buffer"></param> /// <param name="offset"></param> /// <param name="count"></param> public override void Write(byte[] buffer, int offset, int count) { if ( IsCaptured ) { // copy to holding buffer only - we'll write out later _cacheStream.Write(buffer, 0, count); _cachePointer += count; } // just transform this buffer if (TransformWrite != null) buffer = OnTransformWrite(buffer); if (TransformWriteString != null) buffer = OnTransformWriteStringInternal(buffer); if (!IsOutputDelayed) _stream.Write(buffer, offset, buffer.Length); } } The key features are the events and corresponding OnXXX methods that handle the event hookups, and the Write() and Flush() methods of the stream implementation. All the rest of the members tend to be plain jane passthrough stream implementation code without much consequence. I do love the way Action<t> and Func<T> make it so easy to create the event signatures for the various events – sweet. A few Things to consider Performance Response.Filter is not great for performance in general as it adds another layer of indirection to the ASP.NET output pipeline, and this implementation in particular adds a memory hit as it basically duplicates the response output into the cached memory stream which is necessary since you may have to look at the entire response. If you have large pages in particular this can cause potentially serious memory pressure in your server application. So be careful of wholesale adoption of this (or other) Response.Filters. Make sure to do some performance testing to ensure it’s not killing your app’s performance. Response.Filter works everywhere A few questions came up in comments and discussion as to capturing ALL output hitting the site and – yes you can definitely do that by assigning a Response.Filter inside of a module. If you do this however you’ll want to be very careful and decide which content you actually want to capture especially in IIS 7 which passes ALL content – including static images/CSS etc. through the ASP.NET pipeline. So it is important to filter only on what you’re looking for – like the page extension or maybe more effectively the Response.ContentType. Response.Filter Chaining Originally I thought that filter chaining doesn’t work at all due to a bug in the stream implementation code. But it’s quite possible to assign multiple filters to the Response.Filter property. So the following actually works to both compress the output and apply the transformed content: WebUtils.GZipEncodePage(); ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformString += filter_TransformString; Response.Filter = filter; However the following does not work resulting in invalid content encoding errors: ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformString += filter_TransformString; Response.Filter = filter; WebUtils.GZipEncodePage(); In other words multiple Response filters can work together but it depends entirely on the implementation whether they can be chained or in which order they can be chained. In this case running the GZip/Deflate stream filters apparently relies on the original content length of the output and chokes when the content is modified. But if attaching the compression first it works fine as unintuitive as that may seem. Resources Download example code Capture Output from ASP.NET Pages © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET  

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• Service Discovery in WCF 4.0 &ndash; Part 1

  - by Shaun

  When designing a service oriented architecture (SOA) system, there will be a lot of services with many service contracts, endpoints and behaviors. Besides the client calling the service, in a large distributed system a service may invoke other services. In this case, one service might need to know the endpoints it invokes. This might not be a problem in a small system. But when you have more than 10 services this might be a problem. For example in my current product, there are around 10 services, such as the user authentication service, UI integration service, location service, license service, device monitor service, event monitor service, schedule job service, accounting service, player management service, etc..   Benefit of Discovery Service Since almost all my services need to invoke at least one other service. This would be a difficult task to make sure all services endpoints are configured correctly in every service. And furthermore, it would be a nightmare when a service changed its endpoint at runtime. Hence, we need a discovery service to remove the dependency (configuration dependency). A discovery service plays as a service dictionary which stores the relationship between the contracts and the endpoints for every service. By using the discovery service, when service X wants to invoke service Y, it just need to ask the discovery service where is service Y, then the discovery service will return all proper endpoints of service Y, then service X can use the endpoint to send the request to service Y. And when some services changed their endpoint address, all need to do is to update its records in the discovery service then all others will know its new endpoint. In WCF 4.0 Discovery it supports both managed proxy discovery mode and ad-hoc discovery mode. In ad-hoc mode there is no standalone discovery service. When a client wanted to invoke a service, it will broadcast an message (normally in UDP protocol) to the entire network with the service match criteria. All services which enabled the discovery behavior will receive this message and only those matched services will send their endpoint back to the client. The managed proxy discovery service works as I described above. In this post I will only cover the managed proxy mode, where there’s a discovery service. For more information about the ad-hoc mode please refer to the MSDN.   Service Announcement and Probe The main functionality of discovery service should be return the proper endpoint addresses back to the service who is looking for. In most cases the consume service (as a client) will send the contract which it wanted to request to the discovery service. And then the discovery service will find the endpoint and respond. Sometimes the contract and endpoint are not enough. It also contains versioning, extensions attributes. This post I will only cover the case includes contract and endpoint. When a client (or sometimes a service who need to invoke another service) need to connect to a target service, it will firstly request the discovery service through the “Probe” method with the criteria. Basically the criteria contains the contract type name of the target service. Then the discovery service will search its endpoint repository by the criteria. The repository might be a database, a distributed cache or a flat XML file. If it matches, the discovery service will grab the endpoint information (it’s called discovery endpoint metadata in WCF) and send back. And this is called “Probe”. Finally the client received the discovery endpoint metadata and will use the endpoint to connect to the target service. Besides the probe, discovery service should take the responsible to know there is a new service available when it goes online, as well as stopped when it goes offline. This feature is named “Announcement”. When a service started and stopped, it will announce to the discovery service. So the basic functionality of a discovery service should includes: 1, An endpoint which receive the service online message, and add the service endpoint information in the discovery repository. 2, An endpoint which receive the service offline message, and remove the service endpoint information from the discovery repository. 3, An endpoint which receive the client probe message, and return the matches service endpoints, and return the discovery endpoint metadata. WCF 4.0 discovery service just covers all these features in it's infrastructure classes.   Discovery Service in WCF 4.0 WCF 4.0 introduced a new assembly named System.ServiceModel.Discovery which has all necessary classes and interfaces to build a WS-Discovery compliant discovery service. It supports ad-hoc and managed proxy modes. For the case mentioned in this post, what we need to build is a standalone discovery service, which is the managed proxy discovery service mode. To build a managed discovery service in WCF 4.0 just create a new class inherits from the abstract class System.ServiceModel.Discovery.DiscoveryProxy. This class implemented and abstracted the procedures of service announcement and probe. And it exposes 8 abstract methods where we can implement our own endpoint register, unregister and find logic. These 8 methods are asynchronized, which means all invokes to the discovery service are asynchronously, for better service capability and performance. 1, OnBeginOnlineAnnouncement, OnEndOnlineAnnouncement: Invoked when a service sent the online announcement message. We need to add the endpoint information to the repository in this method. 2, OnBeginOfflineAnnouncement, OnEndOfflineAnnouncement: Invoked when a service sent the offline announcement message. We need to remove the endpoint information from the repository in this method. 3, OnBeginFind, OnEndFind: Invoked when a client sent the probe message that want to find the service endpoint information. We need to look for the proper endpoints by matching the client’s criteria through the repository in this method. 4, OnBeginResolve, OnEndResolve: Invoked then a client sent the resolve message. Different from the find method, when using resolve method the discovery service will return the exactly one service endpoint metadata to the client. In our example we will NOT implement this method.   Let’s create our own discovery service, inherit the base System.ServiceModel.Discovery.DiscoveryProxy. We also need to specify the service behavior in this class. Since the build-in discovery service host class only support the singleton mode, we must set its instance context mode to single. 1: using System; 2: using System.Collections.Generic; 3: using System.Linq; 4: using System.Text; 5: using System.ServiceModel.Discovery; 6: using System.ServiceModel; 7:  8: namespace Phare.Service 9: { 10: [ServiceBehavior(InstanceContextMode = InstanceContextMode.Single, ConcurrencyMode = ConcurrencyMode.Multiple)] 11: public class ManagedProxyDiscoveryService : DiscoveryProxy 12: { 13: protected override IAsyncResult OnBeginFind(FindRequestContext findRequestContext, AsyncCallback callback, object state) 14: { 15: throw new NotImplementedException(); 16: } 17:  18: protected override IAsyncResult OnBeginOfflineAnnouncement(DiscoveryMessageSequence messageSequence, EndpointDiscoveryMetadata endpointDiscoveryMetadata, AsyncCallback callback, object state) 19: { 20: throw new NotImplementedException(); 21: } 22:  23: protected override IAsyncResult OnBeginOnlineAnnouncement(DiscoveryMessageSequence messageSequence, EndpointDiscoveryMetadata endpointDiscoveryMetadata, AsyncCallback callback, object state) 24: { 25: throw new NotImplementedException(); 26: } 27:  28: protected override IAsyncResult OnBeginResolve(ResolveCriteria resolveCriteria, AsyncCallback callback, object state) 29: { 30: throw new NotImplementedException(); 31: } 32:  33: protected override void OnEndFind(IAsyncResult result) 34: { 35: throw new NotImplementedException(); 36: } 37:  38: protected override void OnEndOfflineAnnouncement(IAsyncResult result) 39: { 40: throw new NotImplementedException(); 41: } 42:  43: protected override void OnEndOnlineAnnouncement(IAsyncResult result) 44: { 45: throw new NotImplementedException(); 46: } 47:  48: protected override EndpointDiscoveryMetadata OnEndResolve(IAsyncResult result) 49: { 50: throw new NotImplementedException(); 51: } 52: } 53: } Then let’s implement the online, offline and find methods one by one. WCF discovery service gives us full flexibility to implement the endpoint add, remove and find logic. For the demo purpose we will use an internal dictionary to store the services’ endpoint metadata. In the next post we will see how to serialize and store these information in database. Define a concurrent dictionary inside the service class since our it will be used in the multiple threads scenario. 1: [ServiceBehavior(InstanceContextMode = InstanceContextMode.Single, ConcurrencyMode = ConcurrencyMode.Multiple)] 2: public class ManagedProxyDiscoveryService : DiscoveryProxy 3: { 4: private ConcurrentDictionary<EndpointAddress, EndpointDiscoveryMetadata> _services; 5:  6: public ManagedProxyDiscoveryService() 7: { 8: _services = new ConcurrentDictionary<EndpointAddress, EndpointDiscoveryMetadata>(); 9: } 10: } Then we can simply implement the logic of service online and offline. 1: protected override IAsyncResult OnBeginOnlineAnnouncement(DiscoveryMessageSequence messageSequence, EndpointDiscoveryMetadata endpointDiscoveryMetadata, AsyncCallback callback, object state) 2: { 3: _services.AddOrUpdate(endpointDiscoveryMetadata.Address, endpointDiscoveryMetadata, (key, value) => endpointDiscoveryMetadata); 4: return new OnOnlineAnnouncementAsyncResult(callback, state); 5: } 6:  7: protected override void OnEndOnlineAnnouncement(IAsyncResult result) 8: { 9: OnOnlineAnnouncementAsyncResult.End(result); 10: } 11:  12: protected override IAsyncResult OnBeginOfflineAnnouncement(DiscoveryMessageSequence messageSequence, EndpointDiscoveryMetadata endpointDiscoveryMetadata, AsyncCallback callback, object state) 13: { 14: EndpointDiscoveryMetadata endpoint = null; 15: _services.TryRemove(endpointDiscoveryMetadata.Address, out endpoint); 16: return new OnOfflineAnnouncementAsyncResult(callback, state); 17: } 18:  19: protected override void OnEndOfflineAnnouncement(IAsyncResult result) 20: { 21: OnOfflineAnnouncementAsyncResult.End(result); 22: } Regards the find method, the parameter FindRequestContext.Criteria has a method named IsMatch, which can be use for us to evaluate which service metadata is satisfied with the criteria. So the implementation of find method would be like this. 1: protected override IAsyncResult OnBeginFind(FindRequestContext findRequestContext, AsyncCallback callback, object state) 2: { 3: _services.Where(s => findRequestContext.Criteria.IsMatch(s.Value)) 4: .Select(s => s.Value) 5: .All(meta => 6: { 7: findRequestContext.AddMatchingEndpoint(meta); 8: return true; 9: }); 10: return new OnFindAsyncResult(callback, state); 11: } 12:  13: protected override void OnEndFind(IAsyncResult result) 14: { 15: OnFindAsyncResult.End(result); 16: } As you can see, we checked all endpoints metadata in repository by invoking the IsMatch method. Then add all proper endpoints metadata into the parameter. Finally since all these methods are asynchronized we need some AsyncResult classes as well. Below are the base class and the inherited classes used in previous methods. 1: using System; 2: using System.Collections.Generic; 3: using System.Linq; 4: using System.Text; 5: using System.Threading; 6:  7: namespace Phare.Service 8: { 9: abstract internal class AsyncResult : IAsyncResult 10: { 11: AsyncCallback callback; 12: bool completedSynchronously; 13: bool endCalled; 14: Exception exception; 15: bool isCompleted; 16: ManualResetEvent manualResetEvent; 17: object state; 18: object thisLock; 19:  20: protected AsyncResult(AsyncCallback callback, object state) 21: { 22: this.callback = callback; 23: this.state = state; 24: this.thisLock = new object(); 25: } 26:  27: public object AsyncState 28: { 29: get 30: { 31: return state; 32: } 33: } 34:  35: public WaitHandle AsyncWaitHandle 36: { 37: get 38: { 39: if (manualResetEvent != null) 40: { 41: return manualResetEvent; 42: } 43: lock (ThisLock) 44: { 45: if (manualResetEvent == null) 46: { 47: manualResetEvent = new ManualResetEvent(isCompleted); 48: } 49: } 50: return manualResetEvent; 51: } 52: } 53:  54: public bool CompletedSynchronously 55: { 56: get 57: { 58: return completedSynchronously; 59: } 60: } 61:  62: public bool IsCompleted 63: { 64: get 65: { 66: return isCompleted; 67: } 68: } 69:  70: object ThisLock 71: { 72: get 73: { 74: return this.thisLock; 75: } 76: } 77:  78: protected static TAsyncResult End<TAsyncResult>(IAsyncResult result) 79: where TAsyncResult : AsyncResult 80: { 81: if (result == null) 82: { 83: throw new ArgumentNullException("result"); 84: } 85:  86: TAsyncResult asyncResult = result as TAsyncResult; 87:  88: if (asyncResult == null) 89: { 90: throw new ArgumentException("Invalid async result.", "result"); 91: } 92:  93: if (asyncResult.endCalled) 94: { 95: throw new InvalidOperationException("Async object already ended."); 96: } 97:  98: asyncResult.endCalled = true; 99:  100: if (!asyncResult.isCompleted) 101: { 102: asyncResult.AsyncWaitHandle.WaitOne(); 103: } 104:  105: if (asyncResult.manualResetEvent != null) 106: { 107: asyncResult.manualResetEvent.Close(); 108: } 109:  110: if (asyncResult.exception != null) 111: { 112: throw asyncResult.exception; 113: } 114:  115: return asyncResult; 116: } 117:  118: protected void Complete(bool completedSynchronously) 119: { 120: if (isCompleted) 121: { 122: throw new InvalidOperationException("This async result is already completed."); 123: } 124:  125: this.completedSynchronously = completedSynchronously; 126:  127: if (completedSynchronously) 128: { 129: this.isCompleted = true; 130: } 131: else 132: { 133: lock (ThisLock) 134: { 135: this.isCompleted = true; 136: if (this.manualResetEvent != null) 137: { 138: this.manualResetEvent.Set(); 139: } 140: } 141: } 142:  143: if (callback != null) 144: { 145: callback(this); 146: } 147: } 148:  149: protected void Complete(bool completedSynchronously, Exception exception) 150: { 151: this.exception = exception; 152: Complete(completedSynchronously); 153: } 154: } 155: } 1: using System; 2: using System.Collections.Generic; 3: using System.Linq; 4: using System.Text; 5: using System.ServiceModel.Discovery; 6: using Phare.Service; 7:  8: namespace Phare.Service 9: { 10: internal sealed class OnOnlineAnnouncementAsyncResult : AsyncResult 11: { 12: public OnOnlineAnnouncementAsyncResult(AsyncCallback callback, object state) 13: : base(callback, state) 14: { 15: this.Complete(true); 16: } 17:  18: public static void End(IAsyncResult result) 19: { 20: AsyncResult.End<OnOnlineAnnouncementAsyncResult>(result); 21: } 22:  23: } 24:  25: sealed class OnOfflineAnnouncementAsyncResult : AsyncResult 26: { 27: public OnOfflineAnnouncementAsyncResult(AsyncCallback callback, object state) 28: : base(callback, state) 29: { 30: this.Complete(true); 31: } 32:  33: public static void End(IAsyncResult result) 34: { 35: AsyncResult.End<OnOfflineAnnouncementAsyncResult>(result); 36: } 37: } 38:  39: sealed class OnFindAsyncResult : AsyncResult 40: { 41: public OnFindAsyncResult(AsyncCallback callback, object state) 42: : base(callback, state) 43: { 44: this.Complete(true); 45: } 46:  47: public static void End(IAsyncResult result) 48: { 49: AsyncResult.End<OnFindAsyncResult>(result); 50: } 51: } 52:  53: sealed class OnResolveAsyncResult : AsyncResult 54: { 55: EndpointDiscoveryMetadata matchingEndpoint; 56:  57: public OnResolveAsyncResult(EndpointDiscoveryMetadata matchingEndpoint, AsyncCallback callback, object state) 58: : base(callback, state) 59: { 60: this.matchingEndpoint = matchingEndpoint; 61: this.Complete(true); 62: } 63:  64: public static EndpointDiscoveryMetadata End(IAsyncResult result) 65: { 66: OnResolveAsyncResult thisPtr = AsyncResult.End<OnResolveAsyncResult>(result); 67: return thisPtr.matchingEndpoint; 68: } 69: } 70: } Now we have finished the discovery service. The next step is to host it. The discovery service is a standard WCF service. So we can use ServiceHost on a console application, windows service, or in IIS as usual. The following code is how to host the discovery service we had just created in a console application. 1: static void Main(string[] args) 2: { 3: using (var host = new ServiceHost(new ManagedProxyDiscoveryService())) 4: { 5: host.Opened += (sender, e) => 6: { 7: host.Description.Endpoints.All((ep) => 8: { 9: Console.WriteLine(ep.ListenUri); 10: return true; 11: }); 12: }; 13:  14: try 15: { 16: // retrieve the announcement, probe endpoint and binding from configuration 17: var announcementEndpointAddress = new EndpointAddress(ConfigurationManager.AppSettings["announcementEndpointAddress"]); 18: var probeEndpointAddress = new EndpointAddress(ConfigurationManager.AppSettings["probeEndpointAddress"]); 19: var binding = Activator.CreateInstance(Type.GetType(ConfigurationManager.AppSettings["bindingType"], true, true)) as Binding; 20: var announcementEndpoint = new AnnouncementEndpoint(binding, announcementEndpointAddress); 21: var probeEndpoint = new DiscoveryEndpoint(binding, probeEndpointAddress); 22: probeEndpoint.IsSystemEndpoint = false; 23: // append the service endpoint for announcement and probe 24: host.AddServiceEndpoint(announcementEndpoint); 25: host.AddServiceEndpoint(probeEndpoint); 26:  27: host.Open(); 28:  29: Console.WriteLine("Press any key to exit."); 30: Console.ReadKey(); 31: } 32: catch (Exception ex) 33: { 34: Console.WriteLine(ex.ToString()); 35: } 36: } 37:  38: Console.WriteLine("Done."); 39: Console.ReadKey(); 40: } What we need to notice is that, the discovery service needs two endpoints for announcement and probe. In this example I just retrieve them from the configuration file. I also specified the binding of these two endpoints in configuration file as well. 1: <?xml version="1.0"?> 2: <configuration> 3: <startup> 4: <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/> 5: </startup> 6: <appSettings> 7: <add key="announcementEndpointAddress" value="net.tcp://localhost:10010/announcement"/> 8: <add key="probeEndpointAddress" value="net.tcp://localhost:10011/probe"/> 9: <add key="bindingType" value="System.ServiceModel.NetTcpBinding, System.ServiceModel, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/> 10: </appSettings> 11: </configuration> And this is the console screen when I ran my discovery service. As you can see there are two endpoints listening for announcement message and probe message.   Discoverable Service and Client Next, let’s create a WCF service that is discoverable, which means it can be found by the discovery service. To do so, we need to let the service send the online announcement message to the discovery service, as well as offline message before it shutdown. Just create a simple service which can make the incoming string to upper. The service contract and implementation would be like this. 1: [ServiceContract] 2: public interface IStringService 3: { 4: [OperationContract] 5: string ToUpper(string content); 6: } 1: public class StringService : IStringService 2: { 3: public string ToUpper(string content) 4: { 5: return content.ToUpper(); 6: } 7: } Then host this service in the console application. In order to make the discovery service easy to be tested the service address will be changed each time it’s started. 1: static void Main(string[] args) 2: { 3: var baseAddress = new Uri(string.Format("net.tcp://localhost:11001/stringservice/{0}/", Guid.NewGuid().ToString())); 4:  5: using (var host = new ServiceHost(typeof(StringService), baseAddress)) 6: { 7: host.Opened += (sender, e) => 8: { 9: Console.WriteLine("Service opened at {0}", host.Description.Endpoints.First().ListenUri); 10: }; 11:  12: host.AddServiceEndpoint(typeof(IStringService), new NetTcpBinding(), string.Empty); 13:  14: host.Open(); 15:  16: Console.WriteLine("Press any key to exit."); 17: Console.ReadKey(); 18: } 19: } Currently this service is NOT discoverable. We need to add a special service behavior so that it could send the online and offline message to the discovery service announcement endpoint when the host is opened and closed. WCF 4.0 introduced a service behavior named ServiceDiscoveryBehavior. When we specified the announcement endpoint address and appended it to the service behaviors this service will be discoverable. 1: var announcementAddress = new EndpointAddress(ConfigurationManager.AppSettings["announcementEndpointAddress"]); 2: var announcementBinding = Activator.CreateInstance(Type.GetType(ConfigurationManager.AppSettings["bindingType"], true, true)) as Binding; 3: var announcementEndpoint = new AnnouncementEndpoint(announcementBinding, announcementAddress); 4: var discoveryBehavior = new ServiceDiscoveryBehavior(); 5: discoveryBehavior.AnnouncementEndpoints.Add(announcementEndpoint); 6: host.Description.Behaviors.Add(discoveryBehavior); The ServiceDiscoveryBehavior utilizes the service extension and channel dispatcher to implement the online and offline announcement logic. In short, it injected the channel open and close procedure and send the online and offline message to the announcement endpoint.   On client side, when we have the discovery service, a client can invoke a service without knowing its endpoint. WCF discovery assembly provides a class named DiscoveryClient, which can be used to find the proper service endpoint by passing the criteria. In the code below I initialized the DiscoveryClient, specified the discovery service probe endpoint address. Then I created the find criteria by specifying the service contract I wanted to use and invoke the Find method. This will send the probe message to the discovery service and it will find the endpoints back to me. The discovery service will return all endpoints that matches the find criteria, which means in the result of the find method there might be more than one endpoints. In this example I just returned the first matched one back. In the next post I will show how to extend our discovery service to make it work like a service load balancer. 1: static EndpointAddress FindServiceEndpoint() 2: { 3: var probeEndpointAddress = new EndpointAddress(ConfigurationManager.AppSettings["probeEndpointAddress"]); 4: var probeBinding = Activator.CreateInstance(Type.GetType(ConfigurationManager.AppSettings["bindingType"], true, true)) as Binding; 5: var discoveryEndpoint = new DiscoveryEndpoint(probeBinding, probeEndpointAddress); 6:  7: EndpointAddress address = null; 8: FindResponse result = null; 9: using (var discoveryClient = new DiscoveryClient(discoveryEndpoint)) 10: { 11: result = discoveryClient.Find(new FindCriteria(typeof(IStringService))); 12: } 13:  14: if (result != null && result.Endpoints.Any()) 15: { 16: var endpointMetadata = result.Endpoints.First(); 17: address = endpointMetadata.Address; 18: } 19: return address; 20: } Once we probed the discovery service we will receive the endpoint. So in the client code we can created the channel factory from the endpoint and binding, and invoke to the service. When creating the client side channel factory we need to make sure that the client side binding should be the same as the service side. WCF discovery service can be used to find the endpoint for a service contract, but the binding is NOT included. This is because the binding was not in the WS-Discovery specification. In the next post I will demonstrate how to add the binding information into the discovery service. At that moment the client don’t need to create the binding by itself. Instead it will use the binding received from the discovery service. 1: static void Main(string[] args) 2: { 3: Console.WriteLine("Say something..."); 4: var content = Console.ReadLine(); 5: while (!string.IsNullOrWhiteSpace(content)) 6: { 7: Console.WriteLine("Finding the service endpoint..."); 8: var address = FindServiceEndpoint(); 9: if (address == null) 10: { 11: Console.WriteLine("There is no endpoint matches the criteria."); 12: } 13: else 14: { 15: Console.WriteLine("Found the endpoint {0}", address.Uri); 16:  17: var factory = new ChannelFactory<IStringService>(new NetTcpBinding(), address); 18: factory.Opened += (sender, e) => 19: { 20: Console.WriteLine("Connecting to {0}.", factory.Endpoint.ListenUri); 21: }; 22: var proxy = factory.CreateChannel(); 23: using (proxy as IDisposable) 24: { 25: Console.WriteLine("ToUpper: {0} => {1}", content, proxy.ToUpper(content)); 26: } 27: } 28:  29: Console.WriteLine("Say something..."); 30: content = Console.ReadLine(); 31: } 32: } Similarly, the discovery service probe endpoint and binding were defined in the configuration file. 1: <?xml version="1.0"?> 2: <configuration> 3: <startup> 4: <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/> 5: </startup> 6: <appSettings> 7: <add key="announcementEndpointAddress" value="net.tcp://localhost:10010/announcement"/> 8: <add key="probeEndpointAddress" value="net.tcp://localhost:10011/probe"/> 9: <add key="bindingType" value="System.ServiceModel.NetTcpBinding, System.ServiceModel, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/> 10: </appSettings> 11: </configuration> OK, now let’s have a test. Firstly start the discovery service, and then start our discoverable service. When it started it will announced to the discovery service and registered its endpoint into the repository, which is the local dictionary. And then start the client and type something. As you can see the client asked the discovery service for the endpoint and then establish the connection to the discoverable service. And more interesting, do NOT close the client console but terminate the discoverable service but press the enter key. This will make the service send the offline message to the discovery service. Then start the discoverable service again. Since we made it use a different address each time it started, currently it should be hosted on another address. If we enter something in the client we could see that it asked the discovery service and retrieve the new endpoint, and connect the the service.   Summary In this post I discussed the benefit of using the discovery service and the procedures of service announcement and probe. I also demonstrated how to leverage the WCF Discovery feature in WCF 4.0 to build a simple managed discovery service. For test purpose, in this example I used the in memory dictionary as the discovery endpoint metadata repository. And when finding I also just return the first matched endpoint back. I also hard coded the bindings between the discoverable service and the client. In next post I will show you how to solve the problem mentioned above, as well as some additional feature for production usage. You can download the code here.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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• How can I remove the Translation entries in apt?

  - by Lord of Time

  This is the output of aptitude update: Ign http://archive.canonical.com natty InRelease Ign http://extras.ubuntu.com natty InRelease Ign http://dl.google.com stable InRelease Ign http://security.ubuntu.com natty-security InRelease Hit http://deb.torproject.org natty InRelease Get:1 http://dl.google.com stable Release.gpg [198 B] Ign http://us.archive.ubuntu.com natty InRelease Ign http://us.archive.ubuntu.com natty-updates InRelease Hit http://archive.canonical.com natty Release.gpg Hit http://extras.ubuntu.com natty Release.gpg Hit http://security.ubuntu.com natty-security Release.gpg Hit http://us.archive.ubuntu.com natty Release.gpg Hit http://security.ubuntu.com natty-security Release Hit http://archive.canonical.com natty Release Hit http://extras.ubuntu.com natty Release Get:2 http://dl.google.com stable Release [1,338 B] Hit http://us.archive.ubuntu.com natty-updates Release.gpg Hit http://security.ubuntu.com natty-security/main Sources Hit http://archive.canonical.com natty/partner amd64 Packages Hit http://deb.torproject.org natty/main amd64 Packages Hit http://extras.ubuntu.com natty/main Sources Hit http://us.archive.ubuntu.com natty Release Hit http://security.ubuntu.com natty-security/restricted Sources Hit http://security.ubuntu.com natty-security/universe Sources Hit http://security.ubuntu.com natty-security/multiverse Sources Hit http://security.ubuntu.com natty-security/main amd64 Packages Hit http://security.ubuntu.com natty-security/restricted amd64 Packages Ign http://archive.canonical.com natty/partner TranslationIndex Hit http://extras.ubuntu.com natty/main amd64 Packages Ign http://extras.ubuntu.com natty/main TranslationIndex Hit http://security.ubuntu.com natty-security/universe amd64 Packages Hit http://security.ubuntu.com natty-security/multiverse amd64 Packages Ign http://security.ubuntu.com natty-security/main TranslationIndex Ign http://security.ubuntu.com natty-security/multiverse TranslationIndex Ign http://security.ubuntu.com natty-security/restricted TranslationIndex Ign http://deb.torproject.org natty/main TranslationIndex Ign http://security.ubuntu.com natty-security/universe TranslationIndex Hit http://us.archive.ubuntu.com natty-updates Release Hit http://us.archive.ubuntu.com natty/main Sources Hit http://us.archive.ubuntu.com natty/restricted Sources Hit http://us.archive.ubuntu.com natty/universe Sources Hit http://us.archive.ubuntu.com natty/multiverse Sources Hit http://us.archive.ubuntu.com natty/main amd64 Packages Hit http://us.archive.ubuntu.com natty/restricted amd64 Packages Hit http://us.archive.ubuntu.com natty/universe amd64 Packages Hit http://us.archive.ubuntu.com natty/multiverse amd64 Packages Ign http://us.archive.ubuntu.com natty/main TranslationIndex Ign http://us.archive.ubuntu.com natty/multiverse TranslationIndex Ign http://us.archive.ubuntu.com natty/restricted TranslationIndex Ign http://us.archive.ubuntu.com natty/universe TranslationIndex Hit http://us.archive.ubuntu.com natty-updates/main Sources Hit http://us.archive.ubuntu.com natty-updates/restricted Sources Hit http://us.archive.ubuntu.com natty-updates/universe Sources Get:3 http://dl.google.com stable/main amd64 Packages [469 B] Ign http://dl.google.com stable/main TranslationIndex Hit http://us.archive.ubuntu.com natty-updates/multiverse Sources Hit http://us.archive.ubuntu.com natty-updates/main amd64 Packages Hit http://us.archive.ubuntu.com natty-updates/restricted amd64 Packages Hit http://us.archive.ubuntu.com natty-updates/universe amd64 Packages Hit http://us.archive.ubuntu.com natty-updates/multiverse amd64 Packages Ign http://us.archive.ubuntu.com natty-updates/main TranslationIndex Ign http://us.archive.ubuntu.com natty-updates/multiverse TranslationIndex Ign http://us.archive.ubuntu.com natty-updates/restricted TranslationIndex Ign http://us.archive.ubuntu.com natty-updates/universe TranslationIndex Ign http://archive.canonical.com natty/partner Translation-en_US Ign http://extras.ubuntu.com natty/main Translation-en_US Ign http://extras.ubuntu.com natty/main Translation-en Ign http://archive.canonical.com natty/partner Translation-en Ign http://security.ubuntu.com natty-security/main Translation-en_US Ign http://security.ubuntu.com natty-security/main Translation-en Ign http://security.ubuntu.com natty-security/multiverse Translation-en_US Ign http://security.ubuntu.com natty-security/multiverse Translation-en Ign http://security.ubuntu.com natty-security/restricted Translation-en_US Ign http://security.ubuntu.com natty-security/restricted Translation-en Ign http://security.ubuntu.com natty-security/universe Translation-en_US Ign http://security.ubuntu.com natty-security/universe Translation-en Ign http://ppa.launchpad.net natty InRelease Ign http://ppa.launchpad.net natty InRelease Ign http://ppa.launchpad.net natty InRelease Ign http://ppa.launchpad.net natty InRelease Ign http://ppa.launchpad.net natty InRelease Hit http://ppa.launchpad.net natty Release.gpg Hit http://ppa.launchpad.net natty Release.gpg Hit http://ppa.launchpad.net natty Release.gpg Hit http://ppa.launchpad.net natty Release.gpg Hit http://ppa.launchpad.net natty Release.gpg Hit http://ppa.launchpad.net natty Release Ign http://dl.google.com stable/main Translation-en_US Hit http://ppa.launchpad.net natty Release Hit http://ppa.launchpad.net natty Release Hit http://ppa.launchpad.net natty Release Hit http://ppa.launchpad.net natty Release Ign http://dl.google.com stable/main Translation-en Hit http://ppa.launchpad.net natty/main Sources Hit http://ppa.launchpad.net natty/main amd64 Packages Ign http://ppa.launchpad.net natty/main TranslationIndex Hit http://ppa.launchpad.net natty/main Sources Hit http://ppa.launchpad.net natty/main amd64 Packages Ign http://ppa.launchpad.net natty/main TranslationIndex Hit http://ppa.launchpad.net natty/main Sources Hit http://ppa.launchpad.net natty/main amd64 Packages Ign http://ppa.launchpad.net natty/main TranslationIndex Hit http://ppa.launchpad.net natty/main Sources Hit http://ppa.launchpad.net natty/main amd64 Packages Ign http://ppa.launchpad.net natty/main TranslationIndex Hit http://ppa.launchpad.net natty/main Sources Ign http://us.archive.ubuntu.com natty/main Translation-en_US Ign http://us.archive.ubuntu.com natty/main Translation-en Hit http://ppa.launchpad.net natty/main amd64 Packages Ign http://ppa.launchpad.net natty/main TranslationIndex Ign http://us.archive.ubuntu.com natty/multiverse Translation-en_US Ign http://us.archive.ubuntu.com natty/multiverse Translation-en Ign http://us.archive.ubuntu.com natty/restricted Translation-en_US Ign http://us.archive.ubuntu.com natty/restricted Translation-en Ign http://us.archive.ubuntu.com natty/universe Translation-en_US Ign http://us.archive.ubuntu.com natty/universe Translation-en Ign http://us.archive.ubuntu.com natty-updates/main Translation-en_US Ign http://us.archive.ubuntu.com natty-updates/main Translation-en Ign http://us.archive.ubuntu.com natty-updates/multiverse Translation-en_US Ign http://us.archive.ubuntu.com natty-updates/multiverse Translation-en Ign http://us.archive.ubuntu.com natty-updates/restricted Translation-en_US Ign http://us.archive.ubuntu.com natty-updates/restricted Translation-en Ign http://us.archive.ubuntu.com natty-updates/universe Translation-en_US Ign http://us.archive.ubuntu.com natty-updates/universe Translation-en Ign http://ppa.launchpad.net natty/main Translation-en_US Ign http://ppa.launchpad.net natty/main Translation-en Ign http://ppa.launchpad.net natty/main Translation-en_US Ign http://ppa.launchpad.net natty/main Translation-en Ign http://archive.getdeb.net natty-getdeb InRelease Ign http://ppa.launchpad.net natty/main Translation-en_US Ign http://ppa.launchpad.net natty/main Translation-en Ign http://ppa.launchpad.net natty/main Translation-en_US Ign http://ppa.launchpad.net natty/main Translation-en Ign http://ppa.launchpad.net natty/main Translation-en_US Ign http://ppa.launchpad.net natty/main Translation-en Hit http://archive.getdeb.net natty-getdeb Release.gpg Hit http://archive.getdeb.net natty-getdeb Release Ign http://deb.torproject.org natty/main Translation-en_US Ign http://deb.torproject.org natty/main Translation-en Hit http://archive.getdeb.net natty-getdeb/apps amd64 Packages Ign http://archive.getdeb.net natty-getdeb/apps TranslationIndex Ign http://archive.getdeb.net natty-getdeb/apps Translation-en_US Ign http://archive.getdeb.net natty-getdeb/apps Translation-en Fetched 2,005 B in 45s (44 B/s) Reading package lists... Is there any way I can get rid of the Translation stuff? I'm tired of it resulting in tons of repository checks rather than it checking far less repositories (69 actual repos vs. 169 checks)

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• MySQL 5.5 - Lost connection to MySQL server during query

  - by bully

  I have an Ubuntu 12.04 LTS server running at a german hoster (virtualized system). # uname -a Linux ... 3.2.0-27-generic #43-Ubuntu SMP Fri Jul 6 14:25:57 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux I want to migrate a Web CMS system, called Contao. It's not my first migration, but my first migration having connection issues with mysql. Migration went successfully, I have the same Contao version running (it's more or less just copy / paste). For the database behind, I did: apt-get install mysql-server phpmyadmin I set a root password and added a user for the CMS which has enough rights on its own database (and only its database) for doing the stuff it has to do. Data import via phpmyadmin worked just fine. I can access the backend of the CMS (which needs to deal with the database already). If I try to access the frontend now, I get the following error: Fatal error: Uncaught exception Exception with message Query error: Lost connection to MySQL server during query (<query statement here, nothing special, just a select>) thrown in /var/www/system/libraries/Database.php on line 686 (Keep in mind: I can access mysql with phpmyadmin and through the backend, working like a charme, it's just the frontend call causing errors). If I spam F5 in my browser I can sometimes even kill the mysql deamon. If I run # mysqld --log-warnings=2 I get this: ... 120921 7:57:31 [Note] mysqld: ready for connections. Version: '5.5.24-0ubuntu0.12.04.1' socket: '/var/run/mysqld/mysqld.sock' port: 3306 (Ubuntu) 05:57:37 UTC - mysqld got signal 4 ; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail. key_buffer_size=16777216 read_buffer_size=131072 max_used_connections=1 max_threads=151 thread_count=1 connection_count=1 It is possible that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 346679 K bytes of memory Hope that's ok; if not, decrease some variables in the equation. Thread pointer: 0x7f1485db3b20 Attempting backtrace. You can use the following information to find out where mysqld died. If you see no messages after this, something went terribly wrong... stack_bottom = 7f1480041e60 thread_stack 0x30000 mysqld(my_print_stacktrace+0x29)[0x7f1483b96459] mysqld(handle_fatal_signal+0x483)[0x7f1483a5c1d3] /lib/x86_64-linux-gnu/libpthread.so.0(+0xfcb0)[0x7f1482797cb0] /lib/x86_64-linux-gnu/libm.so.6(+0x42e11)[0x7f14821cae11] mysqld(_ZN10SQL_SELECT17test_quick_selectEP3THD6BitmapILj64EEyyb+0x1368)[0x7f1483b26cb8] mysqld(+0x33116a)[0x7f148397916a] mysqld(_ZN4JOIN8optimizeEv+0x558)[0x7f148397d3e8] mysqld(_Z12mysql_selectP3THDPPP4ItemP10TABLE_LISTjR4ListIS1_ES2_jP8st_orderSB_S2_SB_yP13select_resultP18st_select_lex_unitP13st_select_lex+0xdd)[0x7f148397fd7d] mysqld(_Z13handle_selectP3THDP3LEXP13select_resultm+0x17c)[0x7f1483985d2c] mysqld(+0x2f4524)[0x7f148393c524] mysqld(_Z21mysql_execute_commandP3THD+0x293e)[0x7f14839451de] mysqld(_Z11mysql_parseP3THDPcjP12Parser_state+0x10f)[0x7f1483948bef] mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0x1365)[0x7f148394a025] mysqld(_Z24do_handle_one_connectionP3THD+0x1bd)[0x7f14839ec7cd] mysqld(handle_one_connection+0x50)[0x7f14839ec830] /lib/x86_64-linux-gnu/libpthread.so.0(+0x7e9a)[0x7f148278fe9a] /lib/x86_64-linux-gnu/libc.so.6(clone+0x6d)[0x7f1481eba4bd] Trying to get some variables. Some pointers may be invalid and cause the dump to abort. Query (7f1464004b60): is an invalid pointer Connection ID (thread ID): 1 Status: NOT_KILLED From /var/log/syslog: Sep 21 07:17:01 s16477249 CRON[23855]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly) Sep 21 07:18:51 s16477249 kernel: [231923.349159] type=1400 audit(1348204731.333:70): apparmor="STATUS" operation="profile_replace" name="/usr/sbin/mysqld" pid=23946 comm="apparmor_parser" Sep 21 07:18:53 s16477249 /etc/mysql/debian-start[23990]: Upgrading MySQL tables if necessary. Sep 21 07:18:53 s16477249 /etc/mysql/debian-start[23993]: /usr/bin/mysql_upgrade: the '--basedir' option is always ignored Sep 21 07:18:53 s16477249 /etc/mysql/debian-start[23993]: Looking for 'mysql' as: /usr/bin/mysql Sep 21 07:18:53 s16477249 /etc/mysql/debian-start[23993]: Looking for 'mysqlcheck' as: /usr/bin/mysqlcheck Sep 21 07:18:53 s16477249 /etc/mysql/debian-start[23993]: This installation of MySQL is already upgraded to 5.5.24, use --force if you still need to run mysql_upgrade Sep 21 07:18:53 s16477249 /etc/mysql/debian-start[24004]: Checking for insecure root accounts. Sep 21 07:18:53 s16477249 /etc/mysql/debian-start[24009]: Triggering myisam-recover for all MyISAM tables I'm using MyISAM tables all over, nothing with InnoDB there. Starting / stopping mysql is done via sudo service mysql start sudo service mysql stop After using google a little bit, I experimented a little bit with timeouts, correct socket path in the /etc/mysql/my.cnf file, but nothing helped. There are some old (from 2008) Gentoo bugs, where re-compiling just solved the problem. I already re-installed mysql via: sudo apt-get remove mysql-server mysql-common sudo apt-get autoremove sudo apt-get install mysql-server without any results. This is the first time I'm running into this problem, and I'm not very experienced with this kind of mysql 'administration'. So mainly, I want to know if anyone of you could help me out please :) Is it a mysql bug? Is something broken in the Ubuntu repositories? Is this one of those misterious 'use-tcp-connection-instead-of-socket-stuff-because-there-are-problems-on-virtualized-machines-with-sockets'-problem? Or am I completly on the wrong way and I just miss-configured something? Remember, phpmyadmin and access to the backend (which uses the database, too) is just fine. Maybe something with Apache? What can I do? Any help is appreciated, so thanks in advance :)

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• Custom ASP.NET Routing to an HttpHandler

  - by Rick Strahl

  As of version 4.0 ASP.NET natively supports routing via the now built-in System.Web.Routing namespace. Routing features are automatically integrated into the HtttpRuntime via a few custom interfaces. New Web Forms Routing Support In ASP.NET 4.0 there are a host of improvements including routing support baked into Web Forms via a RouteData property available on the Page class and RouteCollection.MapPageRoute() route handler that makes it easy to route to Web forms. To map ASP.NET Page routes is as simple as setting up the routes with MapPageRoute:protected void Application_Start(object sender, EventArgs e) { RegisterRoutes(RouteTable.Routes); } void RegisterRoutes(RouteCollection routes) { routes.MapPageRoute("StockQuote", "StockQuote/{symbol}", "StockQuote.aspx"); routes.MapPageRoute("StockQuotes", "StockQuotes/{symbolList}", "StockQuotes.aspx"); } and then accessing the route data in the page you can then use the new Page class RouteData property to retrieve the dynamic route data information:public partial class StockQuote1 : System.Web.UI.Page { protected StockQuote Quote = null; protected void Page_Load(object sender, EventArgs e) { string symbol = RouteData.Values["symbol"] as string; StockServer server = new StockServer(); Quote = server.GetStockQuote(symbol); // display stock data in Page View } } Simple, quick and doesn’t require much explanation. If you’re using WebForms most of your routing needs should be served just fine by this simple mechanism. Kudos to the ASP.NET team for putting this in the box and making it easy! How Routing Works To handle Routing in ASP.NET involves these steps: Registering Routes Creating a custom RouteHandler to retrieve an HttpHandler Attaching RouteData to your HttpHandler Picking up Route Information in your Request code Registering routes makes ASP.NET aware of the Routes you want to handle via the static RouteTable.Routes collection. You basically add routes to this collection to let ASP.NET know which URL patterns it should watch for. You typically hook up routes off a RegisterRoutes method that fires in Application_Start as I did in the example above to ensure routes are added only once when the application first starts up. When you create a route, you pass in a RouteHandler instance which ASP.NET caches and reuses as routes are matched. Once registered ASP.NET monitors the routes and if a match is found just prior to the HttpHandler instantiation, ASP.NET uses the RouteHandler registered for the route and calls GetHandler() on it to retrieve an HttpHandler instance. The RouteHandler.GetHandler() method is responsible for creating an instance of an HttpHandler that is to handle the request and – if necessary – to assign any additional custom data to the handler. At minimum you probably want to pass the RouteData to the handler so the handler can identify the request based on the route data available. To do this you typically add  a RouteData property to your handler and then assign the property from the RouteHandlers request context. This is essentially how Page.RouteData comes into being and this approach should work well for any custom handler implementation that requires RouteData. It’s a shame that ASP.NET doesn’t have a top level intrinsic object that’s accessible off the HttpContext object to provide route data more generically, but since RouteData is directly tied to HttpHandlers and not all handlers support it it might cause some confusion of when it’s actually available. Bottom line is that if you want to hold on to RouteData you have to assign it to a custom property of the handler or else pass it to the handler via Context.Items[] object that can be retrieved on an as needed basis. It’s important to understand that routing is hooked up via RouteHandlers that are responsible for loading HttpHandler instances. RouteHandlers are invoked for every request that matches a route and through this RouteHandler instance the Handler gains access to the current RouteData. Because of this logic it’s important to understand that Routing is really tied to HttpHandlers and not available prior to handler instantiation, which is pretty late in the HttpRuntime’s request pipeline. IOW, Routing works with Handlers but not with earlier in the pipeline within Modules. Specifically ASP.NET calls RouteHandler.GetHandler() from the PostResolveRequestCache HttpRuntime pipeline event. Here’s the call stack at the beginning of the GetHandler() call: which fires just before handler resolution. Non-Page Routing – You need to build custom RouteHandlers If you need to route to a custom Http Handler or other non-Page (and non-MVC) endpoint in the HttpRuntime, there is no generic mapping support available. You need to create a custom RouteHandler that can manage creating an instance of an HttpHandler that is fired in response to a routed request. Depending on what you are doing this process can be simple or fairly involved as your code is responsible based on the route data provided which handler to instantiate, and more importantly how to pass the route data on to the Handler. Luckily creating a RouteHandler is easy by implementing the IRouteHandler interface which has only a single GetHttpHandler(RequestContext context) method. In this method you can pick up the requestContext.RouteData, instantiate the HttpHandler of choice, and assign the RouteData to it. Then pass back the handler and you’re done.Here’s a simple example of GetHttpHandler() method that dynamically creates a handler based on a passed in Handler type./// <summary> /// Retrieves an Http Handler based on the type specified in the constructor /// </summary> /// <param name="requestContext"></param> /// <returns></returns> IHttpHandler IRouteHandler.GetHttpHandler(RequestContext requestContext) { IHttpHandler handler = Activator.CreateInstance(CallbackHandlerType) as IHttpHandler; // If we're dealing with a Callback Handler // pass the RouteData for this route to the Handler if (handler is CallbackHandler) ((CallbackHandler)handler).RouteData = requestContext.RouteData; return handler; } Note that this code checks for a specific type of handler and if it matches assigns the RouteData to this handler. This is optional but quite a common scenario if you want to work with RouteData. If the handler you need to instantiate isn’t under your control but you still need to pass RouteData to Handler code, an alternative is to pass the RouteData via the HttpContext.Items collection:IHttpHandler IRouteHandler.GetHttpHandler(RequestContext requestContext) { IHttpHandler handler = Activator.CreateInstance(CallbackHandlerType) as IHttpHandler; requestContext.HttpContext.Items["RouteData"] = requestContext.RouteData; return handler; } The code in the handler implementation can then pick up the RouteData from the context collection as needed:RouteData routeData = HttpContext.Current.Items["RouteData"] as RouteData This isn’t as clean as having an explicit RouteData property, but it does have the advantage that the route data is visible anywhere in the Handler’s code chain. It’s definitely preferable to create a custom property on your handler, but the Context work-around works in a pinch when you don’t’ own the handler code and have dynamic code executing as part of the handler execution. An Example of a Custom RouteHandler: Attribute Based Route Implementation In this post I’m going to discuss a custom routine implementation I built for my CallbackHandler class in the West Wind Web & Ajax Toolkit. CallbackHandler can be very easily used for creating AJAX, REST and POX requests following RPC style method mapping. You can pass parameters via URL query string, POST data or raw data structures, and you can retrieve results as JSON, XML or raw string/binary data. It’s a quick and easy way to build service interfaces with no fuss. As a quick review here’s how CallbackHandler works: You create an Http Handler that derives from CallbackHandler You implement methods that have a [CallbackMethod] Attribute and that’s it. Here’s an example of an CallbackHandler implementation in an ashx.cs based handler:// RestService.ashx.cs public class RestService : CallbackHandler { [CallbackMethod] public StockQuote GetStockQuote(string symbol) { StockServer server = new StockServer(); return server.GetStockQuote(symbol); } [CallbackMethod] public StockQuote[] GetStockQuotes(string symbolList) { StockServer server = new StockServer(); string[] symbols = symbolList.Split(new char[2] { ',',';' },StringSplitOptions.RemoveEmptyEntries); return server.GetStockQuotes(symbols); } } CallbackHandler makes it super easy to create a method on the server, pass data to it via POST, QueryString or raw JSON/XML data, and then retrieve the results easily back in various formats. This works wonderful and I’ve used these tools in many projects for myself and with clients. But one thing missing has been the ability to create clean URLs. Typical URLs looked like this: http://www.west-wind.com/WestwindWebToolkit/samples/Rest/StockService.ashx?Method=GetStockQuote&symbol=msfthttp://www.west-wind.com/WestwindWebToolkit/samples/Rest/StockService.ashx?Method=GetStockQuotes&symbolList=msft,intc,gld,slw,mwe&format=xml which works and is clear enough, but also clearly very ugly. It would be much nicer if URLs could look like this: http://www.west-wind.com//WestwindWebtoolkit/Samples/StockQuote/msfthttp://www.west-wind.com/WestwindWebtoolkit/Samples/StockQuotes/msft,intc,gld,slw?format=xml (the Virtual Root in this sample is WestWindWebToolkit/Samples and StockQuote/{symbol} is the route)(If you use FireFox try using the JSONView plug-in make it easier to view JSON content) So, taking a clue from the WCF REST tools that use RouteUrls I set out to create a way to specify RouteUrls for each of the endpoints. The change made basically allows changing the above to: [CallbackMethod(RouteUrl="RestService/StockQuote/{symbol}")] public StockQuote GetStockQuote(string symbol) { StockServer server = new StockServer(); return server.GetStockQuote(symbol); } [CallbackMethod(RouteUrl = "RestService/StockQuotes/{symbolList}")] public StockQuote[] GetStockQuotes(string symbolList) { StockServer server = new StockServer(); string[] symbols = symbolList.Split(new char[2] { ',',';' },StringSplitOptions.RemoveEmptyEntries); return server.GetStockQuotes(symbols); } where a RouteUrl is specified as part of the Callback attribute. And with the changes made with RouteUrls I can now get URLs like the second set shown earlier. So how does that work? Let’s find out… How to Create Custom Routes As mentioned earlier Routing is made up of several steps: Creating a custom RouteHandler to create HttpHandler instances Mapping the actual Routes to the RouteHandler Retrieving the RouteData and actually doing something useful with it in the HttpHandler In the CallbackHandler routing example above this works out to something like this: Create a custom RouteHandler that includes a property to track the method to call Set up the routes using Reflection against the class Looking for any RouteUrls in the CallbackMethod attribute Add a RouteData property to the CallbackHandler so we can access the RouteData in the code of the handler Creating a Custom Route Handler To make the above work I created a custom RouteHandler class that includes the actual IRouteHandler implementation as well as a generic and static method to automatically register all routes marked with the [CallbackMethod(RouteUrl="…")] attribute. Here’s the code:/// <summary> /// Route handler that can create instances of CallbackHandler derived /// callback classes. The route handler tracks the method name and /// creates an instance of the service in a predictable manner /// </summary> /// <typeparam name="TCallbackHandler">CallbackHandler type</typeparam> public class CallbackHandlerRouteHandler : IRouteHandler { /// <summary> /// Method name that is to be called on this route. /// Set by the automatically generated RegisterRoutes /// invokation. /// </summary> public string MethodName { get; set; } /// <summary> /// The type of the handler we're going to instantiate. /// Needed so we can semi-generically instantiate the /// handler and call the method on it. /// </summary> public Type CallbackHandlerType { get; set; } /// <summary> /// Constructor to pass in the two required components we /// need to create an instance of our handler. /// </summary> /// <param name="methodName"></param> /// <param name="callbackHandlerType"></param> public CallbackHandlerRouteHandler(string methodName, Type callbackHandlerType) { MethodName = methodName; CallbackHandlerType = callbackHandlerType; } /// <summary> /// Retrieves an Http Handler based on the type specified in the constructor /// </summary> /// <param name="requestContext"></param> /// <returns></returns> IHttpHandler IRouteHandler.GetHttpHandler(RequestContext requestContext) { IHttpHandler handler = Activator.CreateInstance(CallbackHandlerType) as IHttpHandler; // If we're dealing with a Callback Handler // pass the RouteData for this route to the Handler if (handler is CallbackHandler) ((CallbackHandler)handler).RouteData = requestContext.RouteData; return handler; } /// <summary> /// Generic method to register all routes from a CallbackHandler /// that have RouteUrls defined on the [CallbackMethod] attribute /// </summary> /// <typeparam name="TCallbackHandler">CallbackHandler Type</typeparam> /// <param name="routes"></param> public static void RegisterRoutes<TCallbackHandler>(RouteCollection routes) { // find all methods var methods = typeof(TCallbackHandler).GetMethods(BindingFlags.Instance | BindingFlags.Public); foreach (var method in methods) { var attrs = method.GetCustomAttributes(typeof(CallbackMethodAttribute), false); if (attrs.Length < 1) continue; CallbackMethodAttribute attr = attrs[0] as CallbackMethodAttribute; if (string.IsNullOrEmpty(attr.RouteUrl)) continue; // Add the route routes.Add(method.Name, new Route(attr.RouteUrl, new CallbackHandlerRouteHandler(method.Name, typeof(TCallbackHandler)))); } } } The RouteHandler implements IRouteHandler, and its responsibility via the GetHandler method is to create an HttpHandler based on the route data. When ASP.NET calls GetHandler it passes a requestContext parameter which includes a requestContext.RouteData property. This parameter holds the current request’s route data as well as an instance of the current RouteHandler. If you look at GetHttpHandler() you can see that the code creates an instance of the handler we are interested in and then sets the RouteData property on the handler. This is how you can pass the current request’s RouteData to the handler. The RouteData object also has a  RouteData.RouteHandler property that is also available to the Handler later, which is useful in order to get additional information about the current route. In our case here the RouteHandler includes a MethodName property that identifies the method to execute in the handler since that value no longer comes from the URL so we need to figure out the method name some other way. The method name is mapped explicitly when the RouteHandler is created and here the static method that auto-registers all CallbackMethods with RouteUrls sets the method name when it creates the routes while reflecting over the methods (more on this in a minute). The important point here is that you can attach additional properties to the RouteHandler and you can then later access the RouteHandler and its properties later in the Handler to pick up these custom values. This is a crucial feature in that the RouteHandler serves in passing additional context to the handler so it knows what actions to perform. The automatic route registration is handled by the static RegisterRoutes<TCallbackHandler> method. This method is generic and totally reusable for any CallbackHandler type handler. To register a CallbackHandler and any RouteUrls it has defined you simple use code like this in Application_Start (or other application startup code):protected void Application_Start(object sender, EventArgs e) { // Register Routes for RestService CallbackHandlerRouteHandler.RegisterRoutes<RestService>(RouteTable.Routes); } If you have multiple CallbackHandler style services you can make multiple calls to RegisterRoutes for each of the service types. RegisterRoutes internally uses reflection to run through all the methods of the Handler, looking for CallbackMethod attributes and whether a RouteUrl is specified. If it is a new instance of a CallbackHandlerRouteHandler is created and the name of the method and the type are set. routes.Add(method.Name,           new Route(attr.RouteUrl, new CallbackHandlerRouteHandler(method.Name, typeof(TCallbackHandler) )) ); While the routing with CallbackHandlerRouteHandler is set up automatically for all methods that use the RouteUrl attribute, you can also use code to hook up those routes manually and skip using the attribute. The code for this is straightforward and just requires that you manually map each individual route to each method you want a routed: protected void Application_Start(objectsender, EventArgs e){    RegisterRoutes(RouteTable.Routes);}void RegisterRoutes(RouteCollection routes) { routes.Add("StockQuote Route",new Route("StockQuote/{symbol}",                     new CallbackHandlerRouteHandler("GetStockQuote",typeof(RestService) ) ) );     routes.Add("StockQuotes Route",new Route("StockQuotes/{symbolList}",                     new CallbackHandlerRouteHandler("GetStockQuotes",typeof(RestService) ) ) );}I think it’s clearly easier to have CallbackHandlerRouteHandler.RegisterRoutes() do this automatically for you based on RouteUrl attributes, but some people have a real aversion to attaching logic via attributes. Just realize that the option to manually create your routes is available as well. Using the RouteData in the Handler A RouteHandler’s responsibility is to create an HttpHandler and as mentioned earlier, natively IHttpHandler doesn’t have any support for RouteData. In order to utilize RouteData in your handler code you have to pass the RouteData to the handler. In my CallbackHandlerRouteHandler when it creates the HttpHandler instance it creates the instance and then assigns the custom RouteData property on the handler:IHttpHandler handler = Activator.CreateInstance(CallbackHandlerType) as IHttpHandler; if (handler is CallbackHandler) ((CallbackHandler)handler).RouteData = requestContext.RouteData; return handler; Again this only works if you actually add a RouteData property to your handler explicitly as I did in my CallbackHandler implementation:/// <summary> /// Optionally store RouteData on this handler /// so we can access it internally /// </summary> public RouteData RouteData {get; set; } and the RouteHandler needs to set it when it creates the handler instance. Once you have the route data in your handler you can access Route Keys and Values and also the RouteHandler. Since my RouteHandler has a custom property for the MethodName to retrieve it from within the handler I can do something like this now to retrieve the MethodName (this example is actually not in the handler but target is an instance pass to the processor): // check for Route Data method name if (target is CallbackHandler) { var routeData = ((CallbackHandler)target).RouteData; if (routeData != null) methodToCall = ((CallbackHandlerRouteHandler)routeData.RouteHandler).MethodName; } When I need to access the dynamic values in the route ( symbol in StockQuote/{symbol}) I can retrieve it easily with the Values collection (RouteData.Values["symbol"]). In my CallbackHandler processing logic I’m basically looking for matching parameter names to Route parameters: // look for parameters in the routeif(routeData != null){    string parmString = routeData.Values[parameter.Name] as string;    adjustedParms[parmCounter] = ReflectionUtils.StringToTypedValue(parmString, parameter.ParameterType);} And with that we’ve come full circle. We’ve created a custom RouteHandler() that passes the RouteData to the handler it creates. We’ve registered our routes to use the RouteHandler, and we’ve utilized the route data in our handler. For completeness sake here’s the routine that executes a method call based on the parameters passed in and one of the options is to retrieve the inbound parameters off RouteData (as well as from POST data or QueryString parameters):internal object ExecuteMethod(string method, object target, string[] parameters, CallbackMethodParameterType paramType, ref CallbackMethodAttribute callbackMethodAttribute) { HttpRequest Request = HttpContext.Current.Request; object Result = null; // Stores parsed parameters (from string JSON or QUeryString Values) object[] adjustedParms = null; Type PageType = target.GetType(); MethodInfo MI = PageType.GetMethod(method, BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic); if (MI == null) throw new InvalidOperationException("Invalid Server Method."); object[] methods = MI.GetCustomAttributes(typeof(CallbackMethodAttribute), false); if (methods.Length < 1) throw new InvalidOperationException("Server method is not accessible due to missing CallbackMethod attribute"); if (callbackMethodAttribute != null) callbackMethodAttribute = methods[0] as CallbackMethodAttribute; ParameterInfo[] parms = MI.GetParameters(); JSONSerializer serializer = new JSONSerializer(); RouteData routeData = null; if (target is CallbackHandler) routeData = ((CallbackHandler)target).RouteData; int parmCounter = 0; adjustedParms = new object[parms.Length]; foreach (ParameterInfo parameter in parms) { // Retrieve parameters out of QueryString or POST buffer if (parameters == null) { // look for parameters in the route if (routeData != null) { string parmString = routeData.Values[parameter.Name] as string; adjustedParms[parmCounter] = ReflectionUtils.StringToTypedValue(parmString, parameter.ParameterType); } // GET parameter are parsed as plain string values - no JSON encoding else if (HttpContext.Current.Request.HttpMethod == "GET") { // Look up the parameter by name string parmString = Request.QueryString[parameter.Name]; adjustedParms[parmCounter] = ReflectionUtils.StringToTypedValue(parmString, parameter.ParameterType); } // POST parameters are treated as methodParameters that are JSON encoded else if (paramType == CallbackMethodParameterType.Json) //string newVariable = methodParameters.GetValue(parmCounter) as string; adjustedParms[parmCounter] = serializer.Deserialize(Request.Params["parm" + (parmCounter + 1).ToString()], parameter.ParameterType); else adjustedParms[parmCounter] = SerializationUtils.DeSerializeObject( Request.Params["parm" + (parmCounter + 1).ToString()], parameter.ParameterType); } else if (paramType == CallbackMethodParameterType.Json) adjustedParms[parmCounter] = serializer.Deserialize(parameters[parmCounter], parameter.ParameterType); else adjustedParms[parmCounter] = SerializationUtils.DeSerializeObject(parameters[parmCounter], parameter.ParameterType); parmCounter++; } Result = MI.Invoke(target, adjustedParms); return Result; } The code basically uses Reflection to loop through all the parameters available on the method and tries to assign the parameters from RouteData, QueryString or POST variables. The parameters are converted into their appropriate types and then used to eventually make a Reflection based method call. What’s sweet is that the RouteData retrieval is just another option for dealing with the inbound data in this scenario and it adds exactly two lines of code plus the code to retrieve the MethodName I showed previously – a seriously low impact addition that adds a lot of extra value to this endpoint callback processing implementation. Debugging your Routes If you create a lot of routes it’s easy to run into Route conflicts where multiple routes have the same path and overlap with each other. This can be difficult to debug especially if you are using automatically generated routes like the routes created by CallbackHandlerRouteHandler.RegisterRoutes. Luckily there’s a tool that can help you out with this nicely. Phill Haack created a RouteDebugging tool you can download and add to your project. The easiest way to do this is to grab and add this to your project is to use NuGet (Add Library Package from your Project’s Reference Nodes):   which adds a RouteDebug assembly to your project. Once installed you can easily debug your routes with this simple line of code which needs to be installed at application startup:protected void Application_Start(object sender, EventArgs e) { CallbackHandlerRouteHandler.RegisterRoutes<StockService>(RouteTable.Routes); // Debug your routes RouteDebug.RouteDebugger.RewriteRoutesForTesting(RouteTable.Routes); } Any routed URL then displays something like this: The screen shows you your current route data and all the routes that are mapped along with a flag that displays which route was actually matched. This is useful – if you have any overlap of routes you will be able to see which routes are triggered – the first one in the sequence wins. This tool has saved my ass on a few occasions – and with NuGet now it’s easy to add it to your project in a few seconds and then remove it when you’re done. Routing Around Custom routing seems slightly complicated on first blush due to its disconnected components of RouteHandler, route registration and mapping of custom handlers. But once you understand the relationship between a RouteHandler, the RouteData and how to pass it to a handler, utilizing of Routing becomes a lot easier as you can easily pass context from the registration to the RouteHandler and through to the HttpHandler. The most important thing to understand when building custom routing solutions is to figure out how to map URLs in such a way that the handler can figure out all the pieces it needs to process the request. This can be via URL routing parameters and as I did in my example by passing additional context information as part of the RouteHandler instance that provides the proper execution context. In my case this ‘context’ was the method name, but it could be an actual static value like an enum identifying an operation or category in an application. Basically user supplied data comes in through the url and static application internal data can be passed via RouteHandler property values. Routing can make your application URLs easier to read by non-techie types regardless of whether you’re building Service type or REST applications, or full on Web interfaces. Routing in ASP.NET 4.0 makes it possible to create just about any extensionless URLs you can dream up and custom RouteHanmdler References Sample ProjectIncludes the sample CallbackHandler service discussed here along with compiled versionsof the Westwind.Web and Westwind.Utilities assemblies.  (requires .NET 4.0/VS 2010) West Wind Web Toolkit includes full implementation of CallbackHandler and the Routing Handler West Wind Web Toolkit Source CodeContains the full source code to the Westwind.Web and Westwind.Utilities assemblies usedin these samples. Includes the source described in the post.(Latest build in the Subversion Repository) CallbackHandler Source(Relevant code to this article tree in Westwind.Web assembly) JSONView FireFoxPluginA simple FireFox Plugin to easily view JSON data natively in FireFox.For IE you can use a registry hack to display JSON as raw text.© Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET  AJAX  HTTP  

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• Red Gate Coder interviews: Alex Davies

  - by Michael Williamson

  Alex Davies has been a software engineer at Red Gate since graduating from university, and is currently busy working on .NET Demon. We talked about tackling parallel programming with his actors framework, a scientific approach to debugging, and how JavaScript is going to affect the programming languages we use in years to come. So, if we start at the start, how did you get started in programming? When I was seven or eight, I was given a BBC Micro for Christmas. I had asked for a Game Boy, but my dad thought it would be better to give me a proper computer. For a year or so, I only played games on it, but then I found the user guide for writing programs in it. I gradually started doing more stuff on it and found it fun. I liked creating. As I went into senior school I continued to write stuff on there, trying to write games that weren’t very good. I got a real computer when I was fourteen and found ways to write BASIC on it. Visual Basic to start with, and then something more interesting than that. How did you learn to program? Was there someone helping you out? Absolutely not! I learnt out of a book, or by experimenting. I remember the first time I found a loop, I was like “Oh my God! I don’t have to write out the same line over and over and over again any more. It’s amazing!” When did you think this might be something that you actually wanted to do as a career? For a long time, I thought it wasn’t something that you would do as a career, because it was too much fun to be a career. I thought I’d do chemistry at university and some kind of career based on chemical engineering. And then I went to a careers fair at school when I was seventeen or eighteen, and it just didn’t interest me whatsoever. I thought “I could be a programmer, and there’s loads of money there, and I’m good at it, and it’s fun”, but also that I shouldn’t spoil my hobby. Now I don’t really program in my spare time any more, which is a bit of a shame, but I program all the rest of the time, so I can live with it. Do you think you learnt much about programming at university? Yes, definitely! I went into university knowing how to make computers do anything I wanted them to do. However, I didn’t have the language to talk about algorithms, so the algorithms course in my first year was massively important. Learning other language paradigms like functional programming was really good for breadth of understanding. Functional programming influences normal programming through design rather than actually using it all the time. I draw inspiration from it to write imperative programs which I think is actually becoming really fashionable now, but I’ve been doing it for ages. I did it first! There were also some courses on really odd programming languages, a bit of Prolog, a little bit of C. Having a little bit of each of those is something that I would have never done on my own, so it was important. And then there are knowledge-based courses which are about not programming itself but things that have been programmed like TCP. Those are really important for examples for how to approach things. Did you do any internships while you were at university? Yeah, I spent both of my summers at the same company. I thought I could code well before I went there. Looking back at the crap that I produced, it was only surpassed in its crappiness by all of the other code already in that company. I’m so much better at writing nice code now than I used to be back then. Was there just not a culture of looking after your code? There was, they just didn’t hire people for their abilities in that area. They hired people for raw IQ. The first indicator of it going wrong was that they didn’t have any computer scientists, which is a bit odd in a programming company. But even beyond that they didn’t have people who learnt architecture from anyone else. Most of them had started straight out of university, so never really had experience or mentors to learn from. There wasn’t the experience to draw from to teach each other. In the second half of my second internship, I was being given tasks like looking at new technologies and teaching people stuff. Interns shouldn’t be teaching people how to do their jobs! All interns are going to have little nuggets of things that you don’t know about, but they shouldn’t consistently be the ones who know the most. It’s not a good environment to learn. I was going to ask how you found working with people who were more experienced than you… When I reached Red Gate, I found some people who were more experienced programmers than me, and that was difficult. I’ve been coding since I was tiny. At university there were people who were cleverer than me, but there weren’t very many who were more experienced programmers than me. During my internship, I didn’t find anyone who I classed as being a noticeably more experienced programmer than me. So, it was a shock to the system to have valid criticisms rather than just formatting criticisms. However, Red Gate’s not so big on the actual code review, at least it wasn’t when I started. We did an entire product release and then somebody looked over all of the UI of that product which I’d written and say what they didn’t like. By that point, it was way too late and I’d disagree with them. Do you think the lack of code reviews was a bad thing? I think if there’s going to be any oversight of new people, then it should be continuous rather than chunky. For me I don’t mind too much, I could go out and get oversight if I wanted it, and in those situations I felt comfortable without it. If I was managing the new person, then maybe I’d be keener on oversight and then the right way to do it is continuously and in very, very small chunks. Have you had any significant projects you’ve worked on outside of a job? When I was a teenager I wrote all sorts of stuff. I used to write games, I derived how to do isomorphic projections myself once. I didn’t know what the word was so I couldn’t Google for it, so I worked it out myself. It was horrifically complicated. But it sort of tailed off when I started at university, and is now basically zero. If I do side-projects now, they tend to be work-related side projects like my actors framework, NAct, which I started in a down tools week. Could you explain a little more about NAct? It is a little C# framework for writing parallel code more easily. Parallel programming is difficult when you need to write to shared data. Sometimes parallel programming is easy because you don’t need to write to shared data. When you do need to access shared data, you could just have your threads pile in and do their work, but then you would screw up the data because the threads would trample on each other’s toes. You could lock, but locks are really dangerous if you’re using more than one of them. You get interactions like deadlocks, and that’s just nasty. Actors instead allows you to say this piece of data belongs to this thread of execution, and nobody else can read it. If you want to read it, then ask that thread of execution for a piece of it by sending a message, and it will send the data back by a message. And that avoids deadlocks as long as you follow some obvious rules about not making your actors sit around waiting for other actors to do something. There are lots of ways to write actors, NAct allows you to do it as if it was method calls on other objects, which means you get all the strong type-safety that C# programmers like. Do you think that this is suitable for the majority of parallel programming, or do you think it’s only suitable for specific cases? It’s suitable for most difficult parallel programming. If you’ve just got a hundred web requests which are all independent of each other, then I wouldn’t bother because it’s easier to just spin them up in separate threads and they can proceed independently of each other. But where you’ve got difficult parallel programming, where you’ve got multiple threads accessing multiple bits of data in multiple ways at different times, then actors is at least as good as all other ways, and is, I reckon, easier to think about. When you’re using actors, you presumably still have to write your code in a different way from you would otherwise using single-threaded code. You can’t use actors with any methods that have return types, because you’re not allowed to call into another actor and wait for it. If you want to get a piece of data out of another actor, then you’ve got to use tasks so that you can use “async” and “await” to await asynchronously for it. But other than that, you can still stick things in classes so it’s not too different really. Rather than having thousands of objects with mutable state, you can use component-orientated design, where there are only a few mutable classes which each have a small number of instances. Then there can be thousands of immutable objects. If you tend to do that anyway, then actors isn’t much of a jump. If I’ve already built my system without any parallelism, how hard is it to add actors to exploit all eight cores on my desktop? Usually pretty easy. If you can identify even one boundary where things look like messages and you have components where some objects live on one side and these other objects live on the other side, then you can have a granddaddy object on one side be an actor and it will parallelise as it goes across that boundary. Not too difficult. If we do get 1000-core desktop PCs, do you think actors will scale up? It’s hard. There are always in the order of twenty to fifty actors in my whole program because I tend to write each component as actors, and I tend to have one instance of each component. So this won’t scale to a thousand cores. What you can do is write data structures out of actors. I use dictionaries all over the place, and if you need a dictionary that is going to be accessed concurrently, then you could build one of those out of actors in no time. You can use queuing to marshal requests between different slices of the dictionary which are living on different threads. So it’s like a distributed hash table but all of the chunks of it are on the same machine. That means that each of these thousand processors has cached one small piece of the dictionary. I reckon it wouldn’t be too big a leap to start doing proper parallelism. Do you think it helps if actors get baked into the language, similarly to Erlang? Erlang is excellent in that it has thread-local garbage collection. C# doesn’t, so there’s a limit to how well C# actors can possibly scale because there’s a single garbage collected heap shared between all of them. When you do a global garbage collection, you’ve got to stop all of the actors, which is seriously expensive, whereas in Erlang garbage collections happen per-actor, so they’re insanely cheap. However, Erlang deviated from all the sensible language design that people have used recently and has just come up with crazy stuff. You can definitely retrofit thread-local garbage collection to .NET, and then it’s quite well-suited to support actors, even if it’s not baked into the language. Speaking of language design, do you have a favourite programming language? I’ll choose a language which I’ve never written before. I like the idea of Scala. It sounds like C#, only with some of the niggles gone. I enjoy writing static types. It means you don’t have to writing tests so much. When you say it doesn’t have some of the niggles? C# doesn’t allow the use of a property as a method group. It doesn’t have Scala case classes, or sum types, where you can do a switch statement and the compiler checks that you’ve checked all the cases, which is really useful in functional-style programming. Pattern-matching, in other words. That’s actually the major niggle. C# is pretty good, and I’m quite happy with C#. And what about going even further with the type system to remove the need for tests to something like Haskell? Or is that a step too far? I’m quite a pragmatist, I don’t think I could deal with trying to write big systems in languages with too few other users, especially when learning how to structure things. I just don’t know anyone who can teach me, and the Internet won’t teach me. That’s the main reason I wouldn’t use it. If I turned up at a company that writes big systems in Haskell, I would have no objection to that, but I wouldn’t instigate it. What about things in C#? For instance, there’s contracts in C#, so you can try to statically verify a bit more about your code. Do you think that’s useful, or just not worthwhile? I’ve not really tried it. My hunch is that it needs to be built into the language and be quite mathematical for it to work in real life, and that doesn’t seem to have ended up true for C# contracts. I don’t think anyone who’s tried them thinks they’re any good. I might be wrong. On a slightly different note, how do you like to debug code? I think I’m quite an odd debugger. I use guesswork extremely rarely, especially if something seems quite difficult to debug. I’ve been bitten spending hours and hours on guesswork and not being scientific about debugging in the past, so now I’m scientific to a fault. What I want is to see the bug happening in the debugger, to step through the bug happening. To watch the program going from a valid state to an invalid state. When there’s a bug and I can’t work out why it’s happening, I try to find some piece of evidence which places the bug in one section of the code. From that experiment, I binary chop on the possible causes of the bug. I suppose that means binary chopping on places in the code, or binary chopping on a stage through a processing cycle. Basically, I’m very stupid about how I debug. I won’t make any guesses, I won’t use any intuition, I will only identify the experiment that’s going to binary chop most effectively and repeat rather than trying to guess anything. I suppose it’s quite top-down. Is most of the time then spent in the debugger? Absolutely, if at all possible I will never debug using print statements or logs. I don’t really hold much stock in outputting logs. If there’s any bug which can be reproduced locally, I’d rather do it in the debugger than outputting logs. And with SmartAssembly error reporting, there’s not a lot that can’t be either observed in an error report and just fixed, or reproduced locally. And in those other situations, maybe I’ll use logs. But I hate using logs. You stare at the log, trying to guess what’s going on, and that’s exactly what I don’t like doing. You have to just look at it and see does this look right or wrong. We’ve covered how you get to grip with bugs. How do you get to grips with an entire codebase? I watch it in the debugger. I find little bugs and then try to fix them, and mostly do it by watching them in the debugger and gradually getting an understanding of how the code works using my process of binary chopping. I have to do a lot of reading and watching code to choose where my slicing-in-half experiment is going to be. The last time I did it was SmartAssembly. The old code was a complete mess, but at least it did things top to bottom. There wasn’t too much of some of the big abstractions where flow of control goes all over the place, into a base class and back again. Code’s really hard to understand when that happens. So I like to choose a little bug and try to fix it, and choose a bigger bug and try to fix it. Definitely learn by doing. I want to always have an aim so that I get a little achievement after every few hours of debugging. Once I’ve learnt the codebase I might be able to fix all the bugs in an hour, but I’d rather be using them as an aim while I’m learning the codebase. If I was a maintainer of a codebase, what should I do to make it as easy as possible for you to understand? Keep distinct concepts in different places. And name your stuff so that it’s obvious which concepts live there. You shouldn’t have some variable that gets set miles up the top of somewhere, and then is read miles down to choose some later behaviour. I’m talking from a very much SmartAssembly point of view because the old SmartAssembly codebase had tons and tons of these things, where it would read some property of the code and then deal with it later. Just thousands of variables in scope. Loads of things to think about. If you can keep concepts separate, then it aids me in my process of fixing bugs one at a time, because each bug is going to more or less be understandable in the one place where it is. And what about tests? Do you think they help at all? I’ve never had the opportunity to learn a codebase which has had tests, I don’t know what it’s like! What about when you’re actually developing? How useful do you find tests in finding bugs or regressions? Finding regressions, absolutely. Running bits of code that would be quite hard to run otherwise, definitely. It doesn’t happen very often that a test finds a bug in the first place. I don’t really buy nebulous promises like tests being a good way to think about the spec of the code. My thinking goes something like “This code works at the moment, great, ship it! Ah, there’s a way that this code doesn’t work. Okay, write a test, demonstrate that it doesn’t work, fix it, use the test to demonstrate that it’s now fixed, and keep the test for future regressions.” The most valuable tests are for bugs that have actually happened at some point, because bugs that have actually happened at some point, despite the fact that you think you’ve fixed them, are way more likely to appear again than new bugs are. Does that mean that when you write your code the first time, there are no tests? Often. The chance of there being a bug in a new feature is relatively unaffected by whether I’ve written a test for that new feature because I’m not good enough at writing tests to think of bugs that I would have written into the code. So not writing regression tests for all of your code hasn’t affected you too badly? There are different kinds of features. Some of them just always work, and are just not flaky, they just continue working whatever you throw at them. Maybe because the type-checker is particularly effective around them. Writing tests for those features which just tend to always work is a waste of time. And because it’s a waste of time I’ll tend to wait until a feature has demonstrated its flakiness by having bugs in it before I start trying to test it. You can get a feel for whether it’s going to be flaky code as you’re writing it. I try to write it to make it not flaky, but there are some things that are just inherently flaky. And very occasionally, I’ll think “this is going to be flaky” as I’m writing, and then maybe do a test, but not most of the time. How do you think your programming style has changed over time? I’ve got clearer about what the right way of doing things is. I used to flip-flop a lot between different ideas. Five years ago I came up with some really good ideas and some really terrible ideas. All of them seemed great when I thought of them, but they were quite diverse ideas, whereas now I have a smaller set of reliable ideas that are actually good for structuring code. So my code is probably more similar to itself than it used to be back in the day, when I was trying stuff out. I’ve got more disciplined about encapsulation, I think. There are operational things like I use actors more now than I used to, and that forces me to use immutability more than I used to. The first code that I wrote in Red Gate was the memory profiler UI, and that was an actor, I just didn’t know the name of it at the time. I don’t really use object-orientation. By object-orientation, I mean having n objects of the same type which are mutable. I want a constant number of objects that are mutable, and they should be different types. I stick stuff in dictionaries and then have one thing that owns the dictionary and puts stuff in and out of it. That’s definitely a pattern that I’ve seen recently. I think maybe I’m doing functional programming. Possibly. It’s plausible. If you had to summarise the essence of programming in a pithy sentence, how would you do it? Programming is the form of art that, without losing any of the beauty of architecture or fine art, allows you to produce things that people love and you make money from. So you think it’s an art rather than a science? It’s a little bit of engineering, a smidgeon of maths, but it’s not science. Like architecture, programming is on that boundary between art and engineering. If you want to do it really nicely, it’s mostly art. You can get away with doing architecture and programming entirely by having a good engineering mind, but you’re not going to produce anything nice. You’re not going to have joy doing it if you’re an engineering mind. Architects who are just engineering minds are not going to enjoy their job. I suppose engineering is the foundation on which you build the art. Exactly. How do you think programming is going to change over the next ten years? There will be an unfortunate shift towards dynamically-typed languages, because of JavaScript. JavaScript has an unfair advantage. JavaScript’s unfair advantage will cause more people to be exposed to dynamically-typed languages, which means other dynamically-typed languages crop up and the best features go into dynamically-typed languages. Then people conflate the good features with the fact that it’s dynamically-typed, and more investment goes into dynamically-typed languages. They end up better, so people use them. What about the idea of compiling other languages, possibly statically-typed, to JavaScript? It’s a reasonable idea. I would like to do it, but I don’t think enough people in the world are going to do it to make it pick up. The hordes of beginners are the lifeblood of a language community. They are what makes there be good tools and what makes there be vibrant community websites. And any particular thing which is the same as JavaScript only with extra stuff added to it, although it might be technically great, is not going to have the hordes of beginners. JavaScript is always to be quickest and easiest way for a beginner to start programming in the browser. And dynamically-typed languages are great for beginners. Compilers are pretty scary and beginners don’t write big code. And having your errors come up in the same place, whether they’re statically checkable errors or not, is quite nice for a beginner. If someone asked me to teach them some programming, I’d teach them JavaScript. If dynamically-typed languages are great for beginners, when do you think the benefits of static typing start to kick in? The value of having a statically typed program is in the tools that rely on the static types to produce a smooth IDE experience rather than actually telling me my compile errors. And only once you’re experienced enough a programmer that having a really smooth IDE experience makes a blind bit of difference, does static typing make a blind bit of difference. So it’s not really about size of codebase. If I go and write up a tiny program, I’m still going to get value out of writing it in C# using ReSharper because I’m experienced with C# and ReSharper enough to be able to write code five times faster if I have that help. Any other visions of the future? Nobody’s going to use actors. Because everyone’s going to be running on single-core VMs connected over network-ready protocols like JSON over HTTP. So, parallelism within one operating system is going to die. But until then, you should use actors. More Red Gater Coder interviews

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• Installing SOA Suite 11.1.1.3

  - by James Taylor

  With the release of Oracle SOA Suite 11.1.1.3 last week (28 April 2010) I thought I would attempt to implement a complete SOA Environment with SOA Suite, BPM and OSB on the WLS infrastructure. One major point of difference with the 11.1.1.3 is that is is released as a point release so you must have 11.1.1.2 installed first, then upgrade to 11.1.1.3. This post is performing the upgrade on Linux, if upgrading on windows you will need to substitute the directories and files accordingly. This post assumes that you have SOA Suite 11.1.1.2 installed already. 1. Download 11.1.1.3 software from the following site: http://www.oracle.com/technology/software/products/middleware/htdocs/fmw_11_download.html WLS 11.1.1.3   RCU 11.1.1.3 SOA Suite 11.1.1.3 OSB 11.1.1.3 Copy files to a staging area. For the purpose of this document the staging area is: /u01/stage  2. Shutdown your existing SOA Suite 11.1.1.2 environment 3. Execute the WLS 11.1.1.3 install from the stage directory. wls1033_linux32.bin 4. Choose the existing 11.1.1.2 Middleware Home 5. Ignore the security update notification 6. Accept the default products to be upgraded. 7. Upgrade of WebLogic has been completed   8. Upgrade the SOA Suite database schemas using the RCU utility. Unzip the RCU utility into the staging area and run the install ./u01/stage/rcuHome/bin/rcu 9. Drop the existing Repository and provide connection details 9. Install SOA Suite patch set 11.1.1.3. Unzip the SOA Suite patchset and execute the runInstaller with the following command. ./u01/stage/Disk1/runInstaller –jreLoc $MW_HOME/jdk160_18/jre 10. Choose the existing 11.1.1.2 middleware home 11. Start Install 12. Your SOA Suite Install should now be completed. Now we need to update the database repository. Login to SQLPlus as sysdba and execute the following command. SELECT version, status FROM schema_version_registry where owner = 'DEV_SOAINFRA'; the result should be similar to this: VERSION                        STATUS      OWNER ------------------------------ ----------- ------------------------------ 11.1.1.2.0                     VALID       DEV_SOAINFRA As you can see the version if these repositories are still at 11.1.1.2. 13. To upgrade these versions you have 2 options. 1 install via RCU, but this will remove any existing services. The second option is to use the Patch Set Assistant. From the $MW_HOME directory run the following command ./Oracle_SOA1/bin/psa -dbType Oracle -dbConnectString 'localhost:1521:xe' -dbaUserName sys -schemaUserName DEV_SOAINFRA 14. Install OSB. For the OSB install I did not install the IDE, or the Examples. run the runInstaller from the command line, unzip the OSB download to the stage area. ./u01/stage/osb/Disk1/runInstaller –jreLoc $MW_HOME/jdk160_18/jre 15. Choose Custom Install NOT to install the IDE (Eclipse) or Examples. 16. Unselect the, Examples and IDE checkboxes. 17. Accept the defaults and start installing. 18. Once the install has been completed configure the domain by running the Configuration Wizard. $MW_HOME/oracle_common/common/bin/config.sh You can create a new domain. In this document I will extend the soa_domain. 19. Select the following from the check list. I have selected the BPM Suite, this is unrelated to OSB but wanted it for my development purposes. To use this functionality additional license are required. 20. Configure the database connectivity. 21. Configure the database connectivity for the OSB schema. 22. Accept the defaults if installing on standard machine, if you require a cluster or advanced configuration then choose the option for you. 23. Upgrade is complete and OSB has been installed. Now you can start your environment.

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• Can't install wine (or ia32-libs) in Ubuntu 12.10 64 bit

  - by carestad

  As already pointed out here, people seems to have issues with installing wine in the latest version of Ubuntu. I'm suspecting this only happens with 64 bit users. For example, when trying to install wine, wine1.4, wine1.4:i386, wine1.5, wine1.5:i386, ia32-libs or ia32-libs:i386 with apt-get, I get a lot of dependency errors. Doing a sudo apt-get -f install doesn't seem to do the trick, neither does using aptitude. The errors I get is normally that the packages depend on some :i386 package, but installing those manually doesn't work either because they also have dependency issues (isn't APT supposed to do this automatically?!). I also downloaded CrossOver today and tried installing the .deb manually, but the dependency issues show up there as well. When running sudo apt-get -f install after trying to install the CrossOver .deb, apt-get wants to purge the following packages: ia32-crossover intel-gpu-tools libdrm-nouveau2 libgl1-mesa-dri libva-x11-1 ubuntu-desktop vlc xorg xserver-xorg-video-ati xserver-xorg-video-intel xserver-xorg-video-modesetting xserver-xorg-video-openchrome xserver-xorg-video-radeon xserver-xorg-video-vmware What I've tried so far (and didn't work): Installing synaptic, reloading my repositories, searching for ia32 and installing ia32-libs. Using Ubuntu Software Center to install Wine and ia32-libs. Using apt-get and aptitude to install all the differend varieties of the wine packages, both with and without the :i386 and -amd64 suffixes in package names. Disabling the universe and multiverse repos, run a sudo apt-get update and then re-enable them again. Boot a newly downloaded Ubuntu 12.10 x64 live USB and try to install all the different packages there. What I haven't tried (yet): Boot a newly downloaded Ubuntu 12.10 x32 image and try to install wine there (I'm just guessing that will work). Reinstall Ubuntu. Throw my computer out a window. wine alexander@cosmo:~$ LANGUAGE=en_US sudo apt-get install wine Reading package lists... Done Building dependency tree Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: wine : Depends: wine1.5 but it is not going to be installed E: Unable to correct problems, you have held broken packages. wine-1.4 alexander@cosmo:~$ LANGUAGE=en_US sudo apt-get install wine1.4 (...) The following packages have unmet dependencies: wine1.4 : Depends: wine1.4-i386 (= 1.4.1-0ubuntu1) E: Unable to correct problems, you have held broken packages. wine-1.4:i386 alexander@cosmo:~$ LANGUAGE=en_US sudo apt-get install wine1.4:i386 (...) The following packages have unmet dependencies: libaudio2:i386 : Depends: libxt6:i386 but it is not going to be installed libqtgui4:i386 : Depends: libsm6:i386 but it is not going to be installed libunity-webapps0 : Depends: unity-webapps-service but it is not going to be installed openssh-client : Depends: adduser (>= 3.10) but it is not going to be installed Depends: passwd ssh : Depends: openssh-server wine1.4:i386 : Depends: wine1.4-i386:i386 (= 1.4.1-0ubuntu1) Depends: binfmt-support:i386 (>= 1.1.2) Depends: procps:i386 Recommends: cups-bsd:i386 Recommends: gnome-exe-thumbnailer:i386 but it is not installable or kde-runtime:i386 but it is not going to be installed Recommends: ttf-droid:i386 but it is not installable Recommends: ttf-liberation:i386 but it is not installable Recommends: ttf-mscorefonts-installer:i386 Recommends: ttf-umefont:i386 but it is not installable Recommends: ttf-unfonts-core:i386 but it is not installable Recommends: ttf-wqy-microhei:i386 but it is not installable Recommends: winbind:i386 Recommends: winetricks:i386 but it is not going to be installed Recommends: xdg-utils:i386 but it is not installable E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages. wine-1.5 alexander@cosmo:~$ sudo apt-get install wine1.5 (...) The following packages have unmet dependencies: wine1.5 : Depends: wine1.5-i386 (= 1.5.16-0ubuntu1) E: Unable to correct problems, you have held broken packages. wine-1.5:i386 alexander@cosmo:~$ sudo apt-get install wine1.5:i386 (...) The following packages have unmet dependencies: libaudio2:i386 : Depends: libxt6:i386 but it is not going to be installed libqtgui4:i386 : Depends: libsm6:i386 but it is not going to be installed libunity-webapps0 : Depends: unity-webapps-service but it is not going to be installed openssh-client : Depends: adduser (>= 3.10) but it is not going to be installed Depends: passwd ssh : Depends: openssh-server wine1.5:i386 : Depends: wine1.5-i386:i386 (= 1.5.16-0ubuntu1) but it is not going to be installed Depends: binfmt-support:i386 (>= 1.1.2) Depends: procps:i386 Recommends: cups-bsd:i386 Recommends: gnome-exe-thumbnailer:i386 but it is not installable or kde-runtime:i386 but it is not going to be installed Recommends: ttf-droid:i386 but it is not installable Recommends: ttf-liberation:i386 but it is not installable Recommends: ttf-mscorefonts-installer:i386 Recommends: ttf-umefont:i386 but it is not installable Recommends: ttf-unfonts-core:i386 but it is not installable Recommends: ttf-wqy-microhei:i386 but it is not installable Recommends: winbind:i386 Recommends: winetricks:i386 but it is not going to be installed Recommends: xdg-utils:i386 but it is not installable E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages. ia32-libs alexander@cosmo:~$ sudo apt-get install ia32-libs (...) The following packages have unmet dependencies: ia32-libs : Depends: ia32-libs-multiarch E: Unable to correct problems, you have held broken packages. ia32-libs:i386 alexander@cosmo:~$ sudo apt-get install ia32-libs:i386 (...) Package ia32-libs:i386 is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source However the following packages replace it: lib32z1 lib32ncurses5 lib32bz2-1.0 lib32asound2 E: Package 'ia32-libs:i386' has no installation candidate

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• How to build Open JavaFX for Android.

  - by PictureCo

  Here's a short recipe for baking JavaFX for Android dalvik. We will need just a few ingredients but each one requires special care. So let's get down to the business.  SourcesThe first ingredient is an open JavaFX repository. This should be piece of cake. As always there's a catch. You probably know that dalvik is jdk6 compatible  and also that certain APIs are missing comparing to good old java vm from Oracle.  Fortunately there is a repository which is a backport of regular OpenJFX to jdk7 and going from jdk7 to jdk6 is possible. The first thing to do is to clone or download the repository from https://bitbucket.org/narya/jfx78. Main page of the project says "It works in some cases" so we will presume that it will work in most cases As I've said dalvik vm misses some APIs which would lead to a build failures. To get them use another compatibility repository which is available on GitHub https://github.com/robovm/robovm-jfx78-compat. Download the zip and unzip sources into jfx78/modules/base.We need also a javafx binary stubs. Use jfxrt.jar from jdk8.The last thing to download are freetype sources from http://freetype.org. These will be necessary for native font rendering. Toolchain setup I have to point out that these instructions were tested only on linux. I suppose they will work with minimal changes also on Mac OS. I also presume that you were able to build open JavaFX. That means all tools like ant, gradle, gcc and jdk8 have been installed and are working all right. In addition to this you will need to download and install jdk7, Android SDK and Android NDK for native code compilation.  Installing all of them will take some time. Don't forget to put them in your path. export ANDROID_SDK=/opt/android-sdk-linux export ANDROID_NDK=/opt/android-ndk-r9b export JAVA_HOME=/opt/jdk1.7.0 export PATH=$JAVA_HOME/bin:$ANDROID_SDK/tools:$ANDROID_SDK/platform-tools:$ANDROID_NDK FreetypeUnzip freetype release sources first. We will have to cross compile them for arm. Firstly we will create a standalone toolchain for cross compiling installed in ~/work/ndk-standalone-19. $ANDROID_NDK/build/tools/make-standalone-toolchain.sh  --platform=android-19 --install-dir=~/work/ndk-standalone-19 After the standalone toolchain has been created cross compile freetype with following script: export TOOLCHAIN=~/work/freetype/ndk-standalone-19 export PATH=$TOOLCHAIN/bin:$PATH export FREETYPE=`pwd` ./configure --host=arm-linux-androideabi --prefix=$FREETYPE/install --without-png --without-zlib --enable-shared sed -i 's/\-version\-info \$(version_info)/-avoid-version/' builds/unix/unix-cc.mk make make install It will compile and install freetype library into $FREETYPE/install. We will link to this install dir later on. It would be possible also to link openjfx font support dynamically against skia library available on Android which already contains freetype. It creates smaller result but can have compatibility problems. Patching Download patches javafx-android-compat.patch + android-tools.patch and patch jfx78 repository. I recommend to have look at patches. First one android-compat.patch updates openjfx build script, removes dependency on SharedSecret classes and updates LensLogger to remove dependency on jdk specific PlatformLogger. Second one android-tools.patch creates helper script in android-tools. The script helps to setup javaFX Android projects. Building Now is time to try the build. Run following script: JAVA_HOME=/opt/jdk1.7.0 JDK_HOME=/opt/jdk1.7.0 ANDROID_SDK=/opt/android-sdk-linux ANDROID_NDK=/opt/android-ndk-r9b PATH=$JAVA_HOME/bin:$ANDROID_SDK/tools:$ANDROID_SDK/platform-tools:$ANDROID_NDK:$PATH gradle -PDEBUG -PDALVIK_VM=true -PBINARY_STUB=~/work/binary_stub/linux/rt/lib/ext/jfxrt.jar \ -PFREETYPE_DIR=~/work/freetype/install -PCOMPILE_TARGETS=android If everything went all right the output is in build/android-sdk Create first JavaFX Android project Use gradle script int android-tools. The script sets the project structure for you.   Following command creates Android HelloWorld project which links to a freshly built javafx runtime and to a HelloWorld application. NAME is a name of Android project. DIR where to create our first project. PACKAGE is package name required by Android. It has nothing to do with a packaging of javafx application. JFX_SDK points to our recently built runtime. JFX_APP points to dist directory of javafx application. (where all application jars sit) JFX_MAIN is fully qualified name of a main class. gradle -PDEBUG -PDIR=/home/user/work -PNAME=HelloWorld -PPACKAGE=com.helloworld \ -PJFX_SDK=/home/user/work/jfx78/build/android-sdk -PJFX_APP=/home/user/NetBeansProjects/HelloWorld/dist \ -PJFX_MAIN=com.helloworld.HelloWorld createProject Now cd to the created project and use it like any other android project. ant clean, debug, uninstall, installd will work. I haven't tried it from any IDE Eclipse nor Netbeans. Special thanks to Stefan Fuchs and Daniel Zwolenski for the repositories used in this blog post.

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• ASP.NET MVC: Converting business objects to select list items

  - by DigiMortal

  Some of our business classes are used to fill dropdown boxes or select lists. And often you have some base class for all your business classes. In this posting I will show you how to use base business class to write extension method that converts collection of business objects to ASP.NET MVC select list items without writing a lot of code. BusinessBase, BaseEntity and other base classes I prefer to have some base class for all my business classes so I can easily use them regardless of their type in contexts I need. NB! Some guys say that it is good idea to have base class for all your business classes and they also suggest you to have mappings done same way in database. Other guys say that it is good to have base class but you don’t have to have one master table in database that contains identities of all your business objects. It is up to you how and what you prefer to do but whatever you do – think and analyze first, please. :) To keep things maximally simple I will use very primitive base class in this example. This class has only Id property and that’s it. public class BaseEntity {     public virtual long Id { get; set; } } Now we have Id in base class and we have one more question to solve – how to better visualize our business objects? To users ID is not enough, they want something more informative. We can define some abstract property that all classes must implement. But there is also another option we can use – overriding ToString() method in our business classes. public class Product : BaseEntity {     public virtual string SKU { get; set; }     public virtual string Name { get; set; }       public override string ToString()     {         if (string.IsNullOrEmpty(Name))             return base.ToString();           return Name;     } } Although you can add more functionality and properties to your base class we are at point where we have what we needed: identity and human readable presentation of business objects. Writing list items converter Now we can write method that creates list items for us. public static class BaseEntityExtensions {            public static IEnumerable<SelectListItem> ToSelectListItems<T>         (this IList<T> baseEntities) where T : BaseEntity     {         return ToSelectListItems((IEnumerator<BaseEntity>)                    baseEntities.GetEnumerator());     }       public static IEnumerable<SelectListItem> ToSelectListItems         (this IEnumerator<BaseEntity> baseEntities)     {         var items = new HashSet<SelectListItem>();           while (baseEntities.MoveNext())         {             var item = new SelectListItem();             var entity = baseEntities.Current;               item.Value = entity.Id.ToString();             item.Text = entity.ToString();               items.Add(item);         }           return items;     } } You can see here to overloads of same method. One works with List<T> and the other with IEnumerator<BaseEntity>. Although mostly my repositories return IList<T> when querying data there are always situations where I can use more abstract types and interfaces. Using extension methods in code In your code you can use ToSelectListItems() extension methods like shown on following code fragment. ... var model = new MyFormModel(); model.Statuses = _myRepository.ListStatuses().ToSelectListItems(); ... You can call this method on all your business classes that extend your base entity. Wanna have some fun with this code? Write overload for extension method that accepts selected item ID.

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• OPN Oracle ECM 10g R3 Implementation Boot Camp - (12-14/Abr/10)

  - by Claudia Costa

  É com entusiasmo que lhe anunciamos o bootcamp de Oracle ECM 10g R3 Implementation que irá realizar nos dias 12-14 de Abril  que abordará os tópicos abaixo descritos. Com o objectivo de ajudar os parceiros a desenvolver competências, a Oracle University e a Oracle Alliances&Channel, desenharam este bootcamp, compactando os conteúdos e reduzindo assim os custos. Preço por participante (3 dias) - 1.250 Eur + Iva  Oracle offers the most unified, usable enterprise content management platform in today's market. With centralized control across single or multiple repositories, common core functionality, and easily scalable content management capabilities, Oracle provides content management solutions for many content types and users-wherever they work in the enterprise.   The Oracle Enterprise Content Management (ECM) Implementation Boot Camp examines the fundamental concepts, techniques, and architecture of Oracle's ECM technologies. Join this training to learn how you can manage and maintain unstructured content   Target Audience:  The Oracle ECM Implementation Boot Camp is designed for architects, technical consultants, team/project leaders and functional consultants of our system integrator partners who want to ramp-up on ECM technology.   Contents:  The ECM Implementation Boot Camp is a three-day hands-on workshop, designed for Oracle Partners who are new to ECM, and will provide implementation instruction on the ECM technology offered by Oracle. The boot camp will: • Provide hands-on experience in implementing Oracle's truly unified, open and standard base ECM technology • Provide the strategic direction about Oracle's Fusion Middleware/Enterprise 2.0 and its role in composite application development • Expose broad set of Oracle's ECM technologies.   Objectives: The Oracle ECM Implementation Boot Camp is primarily focused on the Oracle's ECM offering to manage and maintain unstructured content and covers Universal Content Management (UCM), Image and Process Management (IPM), Universal Records Management (URM), and Information Rights Management (IRM):   Topics Covered • Introduction to Oracle UCM o UCM Overview o UCM Architecture Overview • Content Server and Document Management basics o Installation and Administration Skills § User and Security Admin § Configuration (metadata, DCLs, profiles, rules, etc.) § Workflow Admin § System Properties and Component Manager § Managing Subscriptions o Contributing Content § Browser form § WebDAV folder § Desktop Integration o Searching • Web Content Management o Site Studio • Universal Records Management • Information Right Management (IRM) • Image & Process Management (IPM) • Oracle Document Capture • Oracle eMail Archive Service. Labs • Content Server Installation • Use and Administration of Content Server • Introduction to Site Studio • Use and Administration of Records Manager Demo: The R&D Group and the New Patent Focus: Information Rights Management, Knowledge Management, Accounts Payable Image Automation, Imaging and Process Management Case Study Use Case 1: Enable City of Xalco to streamline internal processes by empowering city employees to quickly and efficiently manage and publish information on their employee intranet and eventually public Web site. Use Case 2: Help Acme & Co in archiving its goal is to become "paperless" by managing all of their company's business content in a central, Web-based repository. Acme's business content ranges from policies and procedures to Employee listings and marketing materials.   Agenda: Day 1 ·         ECM Overview & Content Server ·         ECM Overview ·         ECM Architecture and Installation ·         UCM and Digital Asset Management DEMO ·         Lab 1 - Content Server Installation ·         Lab 2 - Use and Administration of Content Server   Day 2 ·         Web Content Management ·         Lab 2 - Use and Administration of Content ·         Server (continued) ·         Introduction to Web Content Management ·         Lab 3 - Site Studio   Day 3 ·         URM/IRM/IPM ·         Introduction to Universal Records Management ·         Lab 4 - URM ·         Introduction to Information Rights Management ·         Information Rights Management DEMO ·         Introduction to Image and Process Management ·         Image and Process Management Demo ·         Oracle Document Capture ·         Oracle eMail Archive   Material needed for Bootcamp: This Boot camp requires attendees to provide their own laptops for this class. Attendee laptops must meet the following minimum hardware/software requirements: Hardware • RAM: 2GB RM minimum (1 GB RAM is not enough) • HDD: 15 GB free HDD space   Pre requistes: To ensure a valuable learning experience, participation in this boot camp requires completing the prerequisite courses and successfully passing the prerequisite assessment test that is mapped into the Oracle Enterprise Content Management Implementation Boot Camp guided learning path. At a minimum, participants with equivalent skills and background should review the guided learning path and successfully pass the prerequisite assessment test to ensure they possess the background necessary to benefit from participation in the boot Camp.   ---------------------------------------------------------------------   Para mais informações/inscrições, contacte: Mónica Pires  21 423 51 44 Horário e Local 9:30h - 12:30h e 14:00h - 17:00 ( 6 horas/dia )Oracle, Porto Salvo - Oeiras.

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• Back Up to Tape the Way You Shop For Groceries

  - by rickramsey

  Imagine if this was how you shopped for groceries: From the end of the aisle sprint to the point where you reach the ketchup. Pull a bottle from the shelf and yell at the top of your lungs, “Got it!” Sprint back to the end of the aisle. Start again and sprint down the same aisle to the mustard, pull a bottle from the shelf and again yell for the whole store to hear, “Got it!” Sprint back to the end of the aisle. Repeat this procedure for every item you need in the aisle. Proceed to the next aisle and follow the same steps for the list of items you need from that aisle. Sounds ridiculous, doesn’t it? Not only is it horribly inefficient, it’s exhausting and can lead to wear out failures on your grocery cart, or worse, yourself. This is essentially how NetApp and some other applications write NDMP backups to tape. In the analogy, the ketchup and mustard are the files to be written, yelling “Got it!” is the equivalent of a sync mark at the end of a file, and the sprint back to the end of an aisle is the process most commonly called a “backhitch” where the drive has to back up on a tape to start writing again. Writing to tape in this way results in very slow tape drive performance and imposes unnecessary wear on the tape drive and the media, especially when writing small files. The good news is not all tape drives behave this way when writing small files. Unlike midrange LTO drives, Oracle’s StorageTek T10000D tape drive is designed to handle this scenario efficiently. The difference between the two drive types is that the T10000D drive gives you the ability to write files in a NetApp NDMP backup environment the way you would normally shop for groceries. With grocery shopping, you essentially stream through aisles picking up items as you go, and then after checking out, yell, “Got it!”, though you might do that last step silently. With the T10000D, it has a feature called the Tape Application Accelerator, which prevents the drive from having to stop after each file is written to notify NetApp or another application that the write was successful. When enabled in the T10000D tape drive, Tape Application Accelerator causes the tape drive to respond to tape mark and file sync commands differently than when disabled: A tape mark received by the tape drive is treated as a buffered tape mark. A file sync received by the tape drive is treated as a no op command. Since buffered tape marks and no op commands do not cause the tape drive to empty the contents of its buffer to tape and backhitch, the data is written to tape in significantly less time. Oracle has emulated NetApp environments with a number of different file sizes and found the following when comparing the T10000D with the Tape Application Accelerator enabled versus LTO6 tape drives. Notice how the T10000D is not only monumentally faster, but also remarkably consistent? In addition, the writing of the 50 GB of files is done without a single backhitch. The LTO6 drive, meanwhile, will perform as many as 3,800 backhitches! At the end of writing the entire set of files, the T10000D tape drive reports back to the application, in this case NetApp, that the write was successful via a tape mark. So if the Tape Application Accelerator dramatically improves performance and reliability, why wouldn’t you always have it enabled? The reason is because tape drive buffers are meant to be just temporary data repositories so in the event of a power loss, there could be data loss in certain environments for the files that resided in the buffer. Fortunately, we do have best practices depending on your environment to avoid this from happening. I highly recommend reading Maximizing Tape Performance with StorageTek T10000 Tape Drives (pdf) to decide which best practice is right for you. The white paper also digs deeper into the benefits of the Tape Application Accelerator. The white paper is free, and after downloading it you can decide for yourself whether you want to yell “Got it!” out loud or just silently to yourself. Customer Advisory Panel One final link: Oracle has started up a Customer Advisory Panel program to collect feedback from customers on their current experiences with Oracle products, as well as desires for future product development. If you would like to participate in the program, go to this link at oracle.com. photo taken on Idaho's Sacajewea Historic Biway by Rick Ramsey - Brian Zents Follow OTN on Blog | Facebook | Twitter | YouTube

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• Oracle’s Web Experience Management

  - by Christie Flanagan

  Today’s guest post on Oracle’s Web Experience Management comes from a member of our WebCenter Evangelist team, Noël Jaffré, a Principal Technologist based in France.Oracle’s Web Experience Management (WEM) solution enables organizations to optimize the online channel for driving marketing and customer experience management success. It empowers business users to manage the web presence and create rich and engaging online experiences for customers and prospects. Oracle's WEM platform provides a framework to simplify the integration of Oracle, third-party and custom-built applications. This framework essentially allows the creation and integration of applications using one single business interface called the WEM interface. It includes the following: Single sign-on access control for all integrated applications using the Central Authentication Service (CAS) component. A single centralized administration window for user, role, and native applications management including site management. Community server management, gadget server management as well as management for partner integrated technologies. A Representational State Transfer (REST) API for accessing WebCenter Sites data. REST services are supported on both Oracle WebCenter Sites and Oracle WebCenter Sites Satellite Server to leverage the satellite server cache. All REST requests are cached for web consuming applications as well for the high performance delivery of native applications on the mobile channel. Oracle WebCenter Sites’ Web Experience Management environment enables organizations to deliver a compelling online experience to customers by simplifying the deployment and management of sophisticated and engaging websites. The WebCenter Sites platform automates the entire process of managing web content including: Authoring:  Business users can easily contribute and manage web content in real-time, with intuitive interfaces and drag-and-drop content authoring and layout capabilities designed for the non-technical user. Contextual Content Targeting: Marketers are empowered to create and manage targeted campaigns with relevant recommendations and promotions based on the context of the session of the visitor such as his or her navigation history, user profile, language, location or other information shared during the visitor session. Content Publishing and Deployment: It offers advanced multi-site management capabilities for departmental or regional sites, as well as strong multi-lingual and multi-locale content management. The remote satellite server caching infrastructure provides high-performance, distributed caching, tuned to deliver high-volume, targeted and multi-lingual sites. Analytics and Optimization: Business users and marketers have the ability to measure the effectiveness of their online content and campaigns at a granular level. Editors and marketers can immediately determine whether a given article or promotion is relevant to a particular customer segment. User-generated Content: Marketers can enable blogs, comments, rating and reviews on the website.  All comments and reviews posted to the website can be moderated from the administrator interface either manually or automatically using filters, whitelists, blacklists or community based moderation. Personalized Gadget Dashboards:  Site managers can deploy gadgets, small applications using web content, individually or as part of dashboards containing multiple gadgets.  These gadget dashboards enable site visitors to create their own “MyPage” on a given site where they can select and customize the gadgets that the site administrator has made available.  Any gadget that conforms to the iGoogle/OpenSocial standard can be made available to site visitors, or they can be created within the WEM interface. Oracle's WEM platform also provides a unique environment for the delivery of a rich, multichannel online experience for site visitors through its advanced management modules for mobile. With Oracle’s WEM solution, it’s easy to control branding and deliver a consistent message while repurposing web content for publication to mobile devices, kiosks and much more. This distinctive approach provides: HTML5 Delivery: HTML5 delivery which includes native support for adaptive design that responds to the user’s computer screen resolution and orientation. The approach is less driven by the particular hardware and more driven by the user’s interactions with the device. In other words, this approach takes both the screen interactions (either cursor or touch) and screen sizes and orientation into consideration. A Unique Native Mobile Extension Environment for Contributors: From the WEM interface, a contributor can directly manage their mobile channel, using the tooling already in place for driving the traditional web presence. This includes the mobile presentation, as well as mobile insite editing, drag and drop page layout, and in-context recommendations and personalization. Optimized REST APIs for High Performance Content Delivery on Native Mobile Device Applications: WebCenter Sites’ REST API uses the underlying HTTP methods (GET, POST, PUT, DELETE) to interact with resources. Resources support two types of input and output formats -- XML and JSON. REST calls are customizable to optimize the interactions between the content repositories and the client applications. Caching is essential to decrease network loads and improve overall reliability and usability of the applications and user interactions. REST results are cached through the highly efficient Oracle WebCenter Sites caching architecture.

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• Using SQL Source Control with Fortress or Vault &ndash; Part 1

  - by AjarnMark

  I am fanatical when it comes to managing the source code for my company.  Everything that we build (in source form) gets put into our source control management system.  And I’m not just talking about the UI and middle-tier code written in C# and ASP.NET, but also the back-end database stuff, which at times has been a pain.  We even script out our Scheduled Jobs and keep a copy of those under source control. The UI and middle-tier stuff has long been easy to manage as we mostly use Visual Studio which has integration with source control systems built in.  But the SQL code has been a little harder to deal with.  I have been doing this for many years, well before Microsoft came up with Data Dude, so I had already established a methodology that, while not as smooth as VS, nonetheless let me keep things well controlled, and allowed doing my database development in my tool of choice, Query Analyzer in days gone by, and now SQL Server Management Studio.  It just makes sense to me that if I’m going to do database development, let’s use the database tool set.  (Although, I have to admit I was pretty impressed with the demo of Juneau that Don Box did at the PASS Summit this year.)  So as I was saying, I had developed a methodology that worked well for us (and I’ll probably outline in a future post) but it could use some improvement. When Solutions and Projects were first introduced in SQL Management Studio, I thought we were finally going to get our same experience that we have in Visual Studio.  Well, let’s say I was underwhelmed by Version 1 in SQL 2005, and apparently so were enough other people that by the time SQL 2008 came out, Microsoft decided that Solutions and Projects would be deprecated and completely removed from a future version.  So much for that idea. Then I came across SQL Source Control from Red-Gate.  I have used several tools from Red-Gate in the past, including my favorites SQL Compare, SQL Prompt, and SQL Refactor.  SQL Prompt is worth its weight in gold, and the others are great, too.  Earlier this year, we upgraded from our earlier product bundles to the new Developer Bundle, and in the process added SQL Source Control to our collection.  I thought this might really be the golden ticket I was looking for.  But my hopes were quickly dashed when I discovered that it only integrated with Microsoft Team Foundation Server and Subversion as the source code repositories.  We have been using SourceGear’s Vault and Fortress products for years, and I wholeheartedly endorse them.  So I was out of luck for the time being, although there were a number of people voting for Vault/Fortress support on their feedback forum (as did I) so I had hope that maybe next year I could look at it again. But just a couple of weeks ago, I was pleasantly surprised to receive notice in my email that Red-Gate had an Early Access version of SQL Source Control that worked with Vault and Fortress, so I quickly downloaded it and have been putting it through its paces.  So far, I really like what I see, and I have been quite impressed with Red-Gate’s responsiveness when I have contacted them with any issues or concerns that I have had.  I have had several communications with Gyorgy Pocsi at Red-Gate and he has been immensely helpful and responsive. I must say that development with SQL Source Control is very different from what I have been used to.  This post is getting long enough, so I’ll save some of the details for a separate write-up, but the short story is that in my regular mode, it’s all about the script files.  Script files are King and you dare not make a change to the database other than by way of a script file, or you are in deep trouble.  With SQL Source Control, you make your changes to your development database however you like.  I still prefer writing most of my changes in T-SQL, but you can also use any of the GUI functionality of SSMS to make your changes, and SQL Source Control “manages” the script for you.  Basically, when you first link your database to source control, the tool generates scripts for every primary object (tables and their indexes are together in one script, not broken out into separate scripts like DB Projects do) and those scripts are checked into your source control.  So, if you needed to, you could still do a GET from your source control repository and build the database from scratch.  But for the day-to-day work, SQL Source Control uses the same technique as SQL Compare to determine what changes have been made to your development database and how to represent those in your repository scripts.  I think that once I retrain myself to just work in the database and quit worrying about having to find and open the right script file, that this will actually make us more efficient. And for deployment purposes, SQL Source Control integrates with the full SQL Compare utility to produce a synchronization script (or do a live sync).  This is similar in concept to Microsoft’s DACPAC, if you’re familiar with that. If you are not currently keeping your database development efforts under source control, definitely examine this tool.  If you already have a methodology that is working for you, then I still think this is worth a review and comparison to your current approach.  You may find it more efficient.  But remember that the version which integrates with Vault/Fortress is still in pre-release mode, so treat it with a little caution.  I have found it to be fairly stable, but there was one bug that I found which had inconvenient side-effects and could have really been frustrating if I had been running this on my normal active development machine.  However, I can verify that that bug has been fixed in a more recent build version (did I mention Red-Gate’s responsiveness?).

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• dpkg unsatisfied dependencies, now apt-get wants to remove whole system

  - by Bruno Finger

  firstly, I'm sorry for my terminal output in portuguese, but I guess it is still understandable. I am using Ubuntu GNOME 14.04 and I tried to update the GNOME Online Accounts packages by downloading the following .deb files from packages.ubuntu.com for the Ubuntu 14.10 version: libgoa-backend-1.0-dev_3.12.4-1_amd64.deb libgoa-backend-1.0-1_3.12.4-1_amd64.deb libgoa-1.0-dev_3.12.4-1_amd64.deb libgoa-1.0-0b_3.12.4-1_amd64.deb gnome-online-accounts_3.12.4-1_amd64.deb gir1.2-goa-1.0_3.12.4-1_amd64.deb After downloading them in the same folder, I run the command sudo dpkg -i *.deb, but it didn't install the packages, instead it showed errors due to packages which them depend doesn't meet the required version (and Ubuntu have no way to install them since they are not in this version's repositories). So now every time I want to install anything through apt-get, Ubuntu tells me to run apt-get -f install to fix the errors. This is the list of packages it needs to install/uninstall/update: $ sudo apt-get -f install Lendo listas de pacotes... Pronto Construindo árvore de dependências Lendo informação de estado... Pronto Corrigindo dependências... Pronto Os seguintes pacotes foram instalados automaticamente e já não são necessários: # THESE PACKAGES HAVE BEEN PREVIOUSLY INSTALLED AND ARE NO LONGER NECESSARY account-plugin-windows-live gir1.2-gweather-3.0 libatk-bridge2.0-dev libatk1.0-dev libcairo-script-interpreter2 libcairo2-dev libexpat1-dev libfontconfig1-dev libfreetype6-dev libgdk-pixbuf2.0-dev libglib2.0-dev libgtk-3-dev libharfbuzz-dev libharfbuzz-gobject0 libice-dev libpango1.0-dev libpcre3-dev libpcrecpp0 libpixman-1-dev libpng12-dev libpthread-stubs0-dev librest-dev libsm-dev libsoup2.4-dev libwayland-dev libx11-dev libx11-doc libxau-dev libxcb-render0-dev libxcb-shm0-dev libxcb1-dev libxcomposite-dev libxcursor-dev libxdamage-dev libxdmcp-dev libxext-dev libxfixes-dev libxft-dev libxi-dev libxinerama-dev libxkbcommon-dev libxml2-dev libxrandr-dev libxrender-dev pkg-config signon-plugin-password x11proto-composite-dev x11proto-core-dev x11proto-damage-dev x11proto-fixes-dev x11proto-input-dev x11proto-kb-dev x11proto-randr-dev x11proto-render-dev x11proto-xext-dev x11proto-xinerama-dev xorg-sgml-doctools xtrans-dev zlib1g-dev Utilize 'apt-get autoremove' para os remover. Os pacotes extra a seguir serão instalados: # THE FOLLOWING PACKAGES WILL BE INSTALLED debhelper dh-apparmor libatk-bridge2.0-dev libatk1.0-dev libcairo-script-interpreter2 libcairo2-dev libept1.4.12 libexpat1-dev libfontconfig1-dev libfreetype6-dev libgdk-pixbuf2.0-dev libglib2.0-dev libgtk-3-dev libharfbuzz-dev libharfbuzz-gobject0 libice-dev libmail-sendmail-perl libpango1.0-dev libpcre3-dev libpcrecpp0 libpixman-1-dev libpng12-dev libpthread-stubs0-dev librest-dev libsm-dev libsoup2.4-dev libwayland-dev libx11-dev libx11-doc libxau-dev libxcb-render0-dev libxcb-shm0-dev libxcb1-dev libxcomposite-dev libxcursor-dev libxdamage-dev libxdmcp-dev libxext-dev libxfixes-dev libxft-dev libxi-dev libxinerama-dev libxkbcommon-dev libxml2-dev libxrandr-dev libxrender-dev pkg-config po-debconf x11proto-composite-dev x11proto-core-dev x11proto-damage-dev x11proto-fixes-dev x11proto-input-dev x11proto-kb-dev x11proto-randr-dev x11proto-render-dev x11proto-xext-dev x11proto-xinerama-dev xorg-sgml-doctools xtrans-dev zlib1g-dev Pacotes sugeridos: dh-make apparmor-easyprof libcairo2-doc libglib2.0-doc libgtk-3-doc libice-doc libpango1.0-doc imagemagick libsm-doc libsoup2.4-doc libxcb-doc libxext-doc libmail-box-perl Os pacotes a seguir serão REMOVIDOS: # THE FOLLOWING PACKAGES WILL BE REMOVED account-plugin-aim account-plugin-jabber account-plugin-salut account-plugin-yahoo empathy evolution evolution-data-server evolution-data-server-online-accounts evolution-indicator evolution-plugins gdm gir1.2-gdata-0.0 gir1.2-goa-1.0 gir1.2-zpj-0.0 gnome-contacts gnome-control-center gnome-documents gnome-online-accounts gnome-online-miners gnome-shell gnome-shell-extension-weather gnome-shell-extensions grilo-plugins-0.2 gvfs-backends-goa libevolution libfolks-eds25 libgdata13 libgoa-1.0-0b libgoa-1.0-dev libgoa-backend-1.0-1 libgoa-backend-1.0-dev libzapojit-0.0-0 mcp-account-manager-uoa nautilus-sendto-empathy ubuntu-gnome-desktop Os NOVOS pacotes a seguir serão instalados: # THE NEW FOLLOWING PACKAGES WILL BE INSTALLED debhelper dh-apparmor libatk-bridge2.0-dev libatk1.0-dev libcairo-script-interpreter2 libcairo2-dev libept1.4.12 libexpat1-dev libfontconfig1-dev libfreetype6-dev libgdk-pixbuf2.0-dev libglib2.0-dev libgtk-3-dev libharfbuzz-dev libharfbuzz-gobject0 libice-dev libmail-sendmail-perl libpango1.0-dev libpcre3-dev libpcrecpp0 libpixman-1-dev libpng12-dev libpthread-stubs0-dev librest-dev libsm-dev libsoup2.4-dev libwayland-dev libx11-dev libx11-doc libxau-dev libxcb-render0-dev libxcb-shm0-dev libxcb1-dev libxcomposite-dev libxcursor-dev libxdamage-dev libxdmcp-dev libxext-dev libxfixes-dev libxft-dev libxi-dev libxinerama-dev libxkbcommon-dev libxml2-dev libxrandr-dev libxrender-dev pkg-config po-debconf x11proto-composite-dev x11proto-core-dev x11proto-damage-dev x11proto-fixes-dev x11proto-input-dev x11proto-kb-dev x11proto-randr-dev x11proto-render-dev x11proto-xext-dev x11proto-xinerama-dev xorg-sgml-doctools xtrans-dev zlib1g-dev 0 pacotes atualizados, 61 pacotes novos instalados, 35 a serem removidos e 22 não atualizados. 7 pacotes não totalmente instalados ou removidos. É preciso baixar 12,0 MB de arquivos. Depois desta operação, 25,0 MB adicionais de espaço em disco serão usados. Você quer continuar? [S/n] Along packages needed to be removed are even gdm. This is 100% sure to make the system useless. What can I do to fix this issue? I don't care if I can't install the new version of goa anymore.

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• JDK bug migration: components and subcomponents

  - by darcy

  One subtask of the JDK migration from the legacy bug tracking system to JIRA was reclassifying bugs from a three-level taxonomy in the legacy system, (product, category, subcategory), to a fundamentally two-level scheme in our customized JIRA instance, (component, subcomponent). In the JDK JIRA system, there is technically a third project-level classification, but by design a large majority of JDK-related bugs were migrated into a single "JDK" project. In the end, over 450 legacy subcategories were simplified into about 120 subcomponents in JIRA. The 120 subcomponents are distributed among 17 components. A rule of thumb used was that a subcategory had to have at least 50 bugs in it for it to be retained. Below is a listing the component / subcomponent classification of the JDK JIRA project along with some notes and guidance on which OpenJDK email addresses cover different areas. Eventually, a separate incidents project to host new issues filed at bugs.sun.com will use a slightly simplified version of this scheme. The preponderance of bugs and subcomponents for the JDK are in library-related areas, with components named foo-libs and subcomponents primarily named after packages. While there was an overall condensation of subcomponents in the migration, in some cases long-standing informal divisions in core libraries based on naming conventions in the description were promoted to formal subcomponents. For example, hundreds of bugs in the java.util subcomponent whose descriptions started with "(coll)" were moved into java.util:collections. Likewise, java.lang bugs starting with "(reflect)" and "(proxy)" were moved into java.lang:reflect. client-libs (Predominantly discussed on 2d-dev and awt-dev and swing-dev.) 2d demo java.awt java.awt:i18n java.beans (See beans-dev.) javax.accessibility javax.imageio javax.sound (See sound-dev.) javax.swing core-libs (See core-libs-dev.) java.io java.io:serialization java.lang java.lang.invoke java.lang:class_loading java.lang:reflect java.math java.net java.nio (Discussed on nio-dev.) java.nio.charsets java.rmi java.sql java.sql:bridge java.text java.util java.util.concurrent java.util.jar java.util.logging java.util.regex java.util:collections java.util:i18n javax.annotation.processing javax.lang.model javax.naming (JNDI) javax.script javax.script:javascript javax.sql org.openjdk.jigsaw (See jigsaw-dev.) security-libs (See security-dev.) java.security javax.crypto (JCE: includes SunJCE/MSCAPI/UCRYPTO/ECC) javax.crypto:pkcs11 (JCE: PKCS11 only) javax.net.ssl (JSSE, includes javax.security.cert) javax.security javax.smartcardio javax.xml.crypto org.ietf.jgss org.ietf.jgss:krb5 other-libs corba corba:idl corba:orb corba:rmi-iiop javadb other (When no other subcomponent is more appropriate; use judiciously.) Most of the subcomponents in the xml component are related to jaxp. xml jax-ws jaxb javax.xml.parsers (JAXP) javax.xml.stream (JAXP) javax.xml.transform (JAXP) javax.xml.validation (JAXP) javax.xml.xpath (JAXP) jaxp (JAXP) org.w3c.dom (JAXP) org.xml.sax (JAXP) For OpenJDK, most JVM-related bugs are connected to the HotSpot Java virtual machine. hotspot (See hotspot-dev.) build compiler (See hotspot-compiler-dev.) gc (garbage collection, see hotspot-gc-dev.) jfr (Java Flight Recorder) jni (Java Native Interface) jvmti (JVM Tool Interface) mvm (Multi-Tasking Virtual Machine) runtime (See hotspot-runtime-dev.) svc (Servicability) test core-svc (See serviceability-dev.) debugger java.lang.instrument java.lang.management javax.management tools The full JDK bug database contains entries related to legacy virtual machines that predate HotSpot as well as retired APIs. vm-legacy jit (Sun Exact VM) jit_symantec (Symantec VM, before Exact VM) jvmdi (JVM Debug Interface ) jvmpi (JVM Profiler Interface ) runtime (Exact VM Runtime) Notable command line tools in the $JDK/bin directory have corresponding subcomponents. tools appletviewer apt (See compiler-dev.) hprof jar javac (See compiler-dev.) javadoc(tool) (See compiler-dev.) javah (See compiler-dev.) javap (See compiler-dev.) jconsole launcher updaters (Timezone updaters, etc.) visualvm Some aspects of JDK infrastructure directly affect JDK Hg repositories, but other do not. infrastructure build (See build-dev and build-infra-dev.) licensing (Covers updates to the third party readme, licenses, and similar files.) release_eng (Release engineering) staging (Staging of web pages related to JDK releases.) The specification subcomponent encompasses the formal language and virtual machine specifications. specification language (The Java Language Specification) vm (The Java Virtual Machine Specification) The code for the deploy and install areas is not currently included in OpenJDK. deploy deployment_toolkit plugin webstart install auto_update install servicetags In the JDK, there are a number of cross-cutting concerns whose organization is essentially orthogonal to other areas. Since these areas generally have dedicated teams working on them, it is easier to find bugs of interest if these bugs are grouped first by their cross-cutting component rather than by the affected technology. docs doclet guides hotspot release_notes tools tutorial embedded build hotspot libraries globalization locale-data translation performance hotspot libraries The list of subcomponents will no doubt grow over time, but my inclination is to resist that growth since the addition of each subcomponent makes the system as a whole more complicated and harder to use. When the system gets closer to being externalized, I plan to post more blog entries describing recommended use of various custom fields in the JDK project.

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• Exalogic 2.0.1 Tea Break Snippets - Modifying the Default Shipped Template

  - by The Old Toxophilist

  Having installed your Exalogic Virtual environment by default you have a single template which can be used to create your vServers. Although this template is suitable for creating simple test or development vServers it is recommended that you look at creating your own custom vServers that match the environment you wish to build and deploy. Therefore this Tea Time Snippet will take you through the simple process of modifying the standard template. Before You Start To edit the template you will need the Oracle ModifyJeos Utility which can be downloaded from the eDelivery Site. Once the ModifyJeos Utility has been downloaded we can install the rpms onto either an existing vServer or one of the Control vServers. rpm -ivh ovm-modify-jeos-1.0.1-10.el5.noarch.rpm rpm -ivh ovm-template-config-1.0.1-5.el5.noarch.rpm Alternatively you can install the modify jeos packages on a none Exalogic OEL installation or a VirtualBox image. If you are doing this, assuming OEL 5u8, you will need the following rpms. rpm -ivh ovm-modify-jeos-1.0.1-10.el5.noarch.rpm rpm -ivh ovm-el5u2-xvm-jeos-1.0.1-5.el5.i386.rpm rpm -ivh ovm-template-config-1.0.1-5.el5.noarch.rpm Base Template If you have installed the modify onto a vServer running on the Exalogic then simply mount the /export/common/images from the ZFS storage and you will be able to find the el_x2-2_base_linux_guest_vm_template_2.0.1.1.0_64.tgz (or similar depending which version you have) template file. Alternatively the latest can be downloaded from the eDelivery Site. Now we have the Template tgz we will need the extract it as follows: tar -zxvf  el_x2-2_base_linux_guest_vm_template_2.0.1.1.0_64.tgz This will create a directory called BASE which will contain the System.img (VServer image) and vm.cfg (VServer Config information). This directory should be renamed to something more meaning full that indicates what we have done to the template and then the Simple name / name in the vm.cfg editted for the same reason. Modifying the Template Resizing Root File System By default the shipped template has a root size of 4 GB which will leave a vServer created from it running at 90% full on the root disk. We can simply resize the template by executing the following: modifyjeos -f System.img -T <New Size MB>) For example to imcrease the default 4 GB to 40 GB we would execute: modifyjeos -f System.img -T 40960) Resizing Swap We can modify the size of the swap space within a template by executing the following: modifyjeos -f System.img -S <New Size MB>) For example to increase the swap from the default 512 MB to 4 GB we would execute: modifyjeos -f System.img -S 4096) Changing RPMs Adding RPMs To add RPMs using modifyjeos, complete the following steps: Add the names of the new RPMs in a list file, such as addrpms.lst. In this file, you should list each new RPM in a separate line. Ensure that all of the new RPMs are in a single directory, such as rpms. Run the following command to add the new RPMs: modifyjeos -f System.img -a <path_to_addrpms.lst> -m <path_to_rpms> -nogpg Where <path_to_addrpms.lst> is the path to the location of the addrpms.lst file, and <path_to_rpms> is the path to the directory that contains the RPMs. The -nogpg option eliminates signature check on the RPMs. Removing RPMs To remove RPM s using modifyjeos, complete the following steps: Add the names of the RPMs (the ones you want to remove) in a list file, such as removerpms.lst. In this file, you should list each RPM in a separate line. The Oracle Exalogic Elastic Cloud Administrator's Guide provides a list of all RPMs that must not be removed from the vServer. Run the following command to remove the RPMs: modifyjeos -f System.img -e <path_to_removerpms.lst> Where <path_to_removerpms.lst> is the path to the location of the removerpms.lst file. Mounting the System.img For all other modifications that are not supported by the modifyjeos command (adding you custom yum repositories, pre configuring NTP, modify default NFSv4 Nobody functionality, etc) we can mount the System.img and access it directly. To facititate quick and easy mounting/unmounting of the System.img I have put together the simple scripts below. MountSystemImg.sh #!/bin/sh # The script assumes it's being run from the directory containing the System.img # Export for later i.e. during unmount export LOOP=`losetup -f` export SYSTEMIMG=/mnt/elsystem # Make Temp Mount Directory mkdir -p $SYSTEMIMG # Create Loop for the System Image losetup $LOOP System.img kpartx -a $LOOP mount /dev/mapper/`basename $LOOP`p2 $SYSTEMIMG #Change Dir into mounted Image cd $SYSTEMIMG UnmountSystemImg.sh #!/bin/sh # The script assumes it's being run from the directory containing the System.img # Assume the $LOOP & $SYSTEMIMG exist from a previous run on the MountSystemImg.sh umount $SYSTEMIMG kpartx -d $LOOP losetup -d $LOOP Packaging the Template Once you have finished modifying the template it can be simply repackaged and then imported into EMOC as described in "Exalogic 2.0.1 Tea Break Snippets - Importing Public Server Template". To do this we will simply cd to the directory above that containing the modified files and execute the following: tar -zcvf <New Template Directory> <New Template Name>.tgz The resulting.tgz file can be copied to the images directory on the ZFS and uploadd using the IB network. This entry was originally posted on the The Old Toxophilist Site.

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