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• What is a simple way to add a timer to a method

  - by John

  The following is in C#. I'm trying to do something very simple (I think). I have a method that loads an XML document XDocument doc = XDocument.Load(uri); , but I don't want to tie up pc resources if there are issues (connectivity, document size, etc.). So I'd like to be able to add a timeout variable that will cut the method off after a given number of seconds. I'm a newbie when it comes to asynchronous programming and find it confusing that there are so many examples written so many different ways . . . and none of them appear simple. I'd like a simple solution, if possible. Here's my thoughts so far on possible solution paths: 1) A method that wraps the existing load public XDocument LoadXDocument(string uri, int timeout){ //code } 2) A wrapper, but as an extension method XDocument doc = XDocument.LoadWithTimeout(string uri, int timeout); 3) A generic extension method. Object obj = SomeStaticClass.LoadWithTimeout(??? method, int timeout); 3), on its face seems really nice, because it would mean being able to generically add timeouts to many different method calls and not specifically tied to one type of object, but I suspect that it is either i)impossible or ii) very difficult. Please assist. Thanks.

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• How can I make an prototype ajax request with an array of values as a parameter?

  - by andresbravog

  i'm trying to make a ajax update in prototype with some values from a multirecordselect that sends a requests like. Parameters: {"action"=>"use_campaign", "campaigns"=> ["27929","27932"] , "advertiser_id"=>"", "controller"=>"admin/reporting", "ad_id"=>""} as you can see the request sends the "campaigns" elements as an array of values, i'm trying to do the same with this js code over prototype 7. // get the campaigns var campaign_ids = {}; var campaigns = $('filter_form').getInputs("hidden","report[campaigns][]"); campaigns.each( function(field) { campaign_ids.push(field.value); }); new Ajax.Updater('ad_filter', '/admin/reporting/use_campaign', { method : 'get', asynchronous : true, evalScripts : true, parameters : { 'advertiser_id' : $('filter_form')['report[advertiser_id]'].value, 'ad_id' : $('filter_form')['report[ad_id]'].value, 'campaigns' : campaign_ids } }); the campaigns_ids is getting the correct info as an array like: [ "27929", "27932" ] but seems that prototype ajax update is sending a request like: http://my_domain/admin/reporting/use_campaign?ad_id=&advertiser_id=&campaigns=27929&campaigns=27932 what sends parameters like: Parameters: {"action"=>"use_campaign", "campaigns"=> "27929" , "advertiser_id"=>"", "controller"=>"admin/reporting", "ad_id"=>""} I also tryed with Object.toJSON(campaign_ids) but i only get an escaped string like Parameters: {"action"=>"use_campaign", "campaigns"=>"[\"27929\",\"27932\"]" , "advertiser_id"=>"", "controller"=>"admin/reporting", "ad_id"=>""} There is anyway to do this as I wish? Thanks for all.

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• A generic C++ library that provides QtConcurrent functionality?

  - by Lucas

  QtConcurrent is awesome. I'll let the Qt docs speak for themselves: QtConcurrent includes functional programming style APIs for parallel list processing, including a MapReduce and FilterReduce implementation for shared-memory (non-distributed) systems, and classes for managing asynchronous computations in GUI applications. For instance, you give QtConcurrent::map() an iterable sequence and a function that accepts items of the type stored in the sequence, and that function is applied to all the items in the collection. This is done in a multi-threaded manner, with a thread pool equal to the number of logical CPU's on the system. There are plenty of other function in QtConcurrent, like filter(), filteredReduced() etc. The standard CompSci map/reduce functions and the like. I'm totally in love with this, but I'm starting work on an OSS project that will not be using the Qt framework. It's a library, and I don't want to force others to depend on such a large framework like Qt. I'm trying to keep external dependencies to a minimum (it's the decent thing to do). I'm looking for a generic C++ framework that provides me with the same/similar high-level primitives that QtConcurrent does. AFAIK boost has nothing like this (I may be wrong though). boost::thread is very low-level compared to what I'm looking for. I know C# has something very similar with their Parallel Extensions so I know this isn't a Qt-only idea. What do you suggest I use?

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• Time gaps between host clEnqueue_xxx calls

  - by dialer

  Consider these OpenCL calls (3 memcpy DtoH, 4313 cl_float elements each): clEnqueueReadBuffer(CommandQueue, SpectrumAbsMem, CL_FALSE, 0, SpectrumMemSize, SpectrumAbs, 0, NULL, NULL); clEnqueueReadBuffer(CommandQueue, SpectrumReMem, CL_FALSE, 0, SpectrumMemSize, SpectrumRe, 0, NULL, NULL); clEnqueueReadBuffer(CommandQueue, SpectrumImMem, CL_FALSE, 0, SpectrumMemSize, SpectrumIm, 0, NULL, NULL); When I analyze these with the NVIDIA visual profiler, I see that the actual memcpy operation only takes 8 us, but there is a significant gap of around 130 us after each memcpy. I'm already using the supposedly asynchronous method (the CL_FALSE in the argument list). When I use only one operation, but with three times the size, the operation is way faster. Why is the time gap between the actual memcpy operations so huge, whereas the gap between the kernel execution (exactly before these three operations) and the first memcpy is only 7us? Can I get rid of it, or do I need to accumulate more data before starting a memcpy? If so, is there a convenient way how I could combine mutliple arrays into a single contiguous block of memory, but still have a cl_mem object as a separate device memory pointer to each section?

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• Prototype: Form.serialize missing some inputs (due to table?)

  - by Chris

  I'm using JavaScript Prototype (through Ruby on Rails) to handle some Ajax calls; but in one particular case I'm missing a field from the form. I have a layout like this: +---------+---------+ | Thing 1 | Thing 2 | +---------+---------+-----------+ | o Opt 1 | o Opt 1 | <Confirm> | | o Opt 2 | o Opt 2 | | +---------+---------+-----------+ Opt 1 and 2 are Radio buttons, Confirm is a button. The entire table is wrapped in a form, with code like: <form action="javascript:void(0)"> <input type="hidden" name="context" value="foo" /> <input type="hidden" name="subcontext" value="bar" /> <table> <tr><td>Thing 1</td><td>Thing2</td></tr> <tr><td> <input type="radio" name="choice" value="1.1" />Opt 1<br /> <input type="radio" name="choice" value="1.2" />Opt 2<br /> </td><td> <input type="radio" name="choice" value="2.1" />Opt 1<br /> <input type="radio" name="choice" value="2.2" />Opt 2<br /> </td><td> <input name="choice_btn" type="button" value="Confirm" onclick="new AJAX.Updater('my_form', '/process_form', {asynchronous:true, evalScripts:true, parameters:Form.serialize(this.form)}); return false;" /> </td></tr> </table> </form> But I can see that the POST generated by clicking the Confirm button contains the foo and bar values for the hidden fields, but not the choice of the radio buttons. Is this because I've got a table inside my form? How can I get around this?

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• Using delegate Types vs methods

  - by Grant Sutcliffe

  I see increasing use of the delegate types offered in the System namespace (Action; Predicate etc). As these are delegates, my understanding is that they should be used where we have traditionally used delegates in the past (asynchronous calls; starting threads, event handling etc). Is it just preference or is it considered practice to use these delegate types in scenarios such as the below; rather than using calls to methods we have declared (or anonymous methods): public void MyMethod { Action<string> action = delegate(string userName { try { XmlDocument profile = DataHelper.GetProfile(userName); UpdateMember(profile); } catch (Exception exception) { if (_log.IsErrorEnabled) _log.ErrorFormat(exception.Message); throw (exception); } }; GetUsers().ForEach(action); } At first, I found the code less intuitive to follow than using declared or anonymous methods. I am starting to code this way, and wonder what the view are in this regard. The example above is all within a method. Is this delegate overuse.

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• How to manage large amounts of delegates and usercallbacks in C# async http library

  - by Tyler

  I'm coding a .NET library in C# for communicating with XBMC via its JSON RPC interface using HTTP. I coded and released a preliminary version but everything is done synchronously. I then recoded the library to be asynchronous for my own purposes as I was/am building an XBMC remote for WP7. I now want to release the new async library but want to make sure it's nice and tidy before I do. Due to the async nature a user initiates a request, supplies a callback method that matches my delegate and then handles the response once it's been received. The problem I have is that within the library I track a RequestState object for the lifetime of the request, it contains the http request/response as well as the user callback etc. as member variables, this would be fine if only one type of object was coming back but depending on what the user calls they may be returned a list of songs or a list of movies etc. My implementation at the moment uses a single delegate ResponseDataRecieved which has a single parameter which is a simple Object - As this has only be used by me I know which methods return what and when I handle the response I cast said object to the type I know it really is - List, List etc. A third party shouldn't have to do this though - The delegate signature should contain the correct type of object. So then I need a delegate for every type of response data that can be returned to the third party - The specific problem is, how do I handle this gracefully internally - Do I have a bunch of different RequestState objects that each have a different member variable for the different delegates? That doesn't "feel" right. I just don't know how to do this gracefully and cleanly.

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• Low Throughput on Windows Named Pipe Over WAN

  - by MichaelB76

  I'm having problems with low performance using a Windows named pipe. The throughput drops off rapidly as the network latency increases. There is a roughly linear relationship between messages sent per second and round trip time. It seems that the client must ack each message before the server will send the next one. This leads to very poor performance, I can only send 5 (~100 byte) messages per second over a link with an RTT of 200 ms. The pipe is asynchronous, using multiple overlapped write operations (and multiple overlapped reads at the client end), but this is not improving throughput. Is it possible to send messages in parallel over a named pipe? The pipe is created using PIPE_TYPE_MESSAGE, would PIPE_READMODE_BYTE work better? Is there any other way I can improve performance? This is a deployed solution, so I can't simply replace the pipe with a socket connection (I've read that Windows named pipe aren't recommended for use over a WAN, and I'm wondering if this is why). I'd be grateful for any help with this matter.

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• JMS message. Model to include data or pointers to data?

  - by John

  I am trying to resolve a design difference of opinion where neither of us has experience with JMS. We want to use JMS to communicate between a j2ee application and the stand-alone application when a new event occurs. We would be using a single point-to-point queue. Both sides are Java-based. The question is whether to send the event data itself in the JMS message body or to send a pointer to the data so that the stand-alone program can retrieve it. Details below. I have a j2ee application that supports data entry of new and updated persons and related events. The person records and associated events are written to an Oracle database. There are also stand-alone, separate programs that contribute new person and event records to the database. When a new event occurs through any of 5-10 different application functions, I need to notify remote systems through an outbound interface using an industry-specific standard messaging protocol. The outbound interface has been designed as a stand-alone application to support scalability through asynchronous operation and by moving it to a separate server. The j2ee application currently has most of the data in memory at the time the event is entered. The data would consist of approximately 6 different objects; a person object and some with multiple instances for an average size in the range of 3000 to 20,000 bytes. Some special cases could be many times this amount. From a performance and reliability perspective, should I model the JMS message to pass all the data needed to create the interface message, or model the JMS message to contain record keys for the data and have the stand-alone Java application retrieve the data to create the interface message?

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• Starting a process synchronously, and "streaming" the output

  - by Benjol

  I'm looking at trying to start a process from F#, wait till it's finished, but also read it's output progressively. Is this the right/best way to do it? (In my case I'm trying to execute git commands, but that is tangential to the question) let gitexecute (logger:string->unit) cmd = let procStartInfo = new ProcessStartInfo(@"C:\Program Files\Git\bin\git.exe", cmd) // Redirect to the Process.StandardOutput StreamReader. procStartInfo.RedirectStandardOutput <- true procStartInfo.UseShellExecute <- false; // Do not create the black window. procStartInfo.CreateNoWindow <- true; // Create a process, assign its ProcessStartInfo and start it let proc = new Process(); proc.StartInfo <- procStartInfo; proc.Start() |> ignore // Get the output into a string while not proc.StandardOutput.EndOfStream do proc.StandardOutput.ReadLine() |> logger What I don't understand is how the proc.Start() can return a boolean and also be asynchronous enough for me to get the output out of the while progressively. Unfortunately, I don't currently have a large enough repository - or slow enough machine, to be able to tell what order things are happening in...

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• Android Facebook RequestListener

  - by Marcus King

  I'm new to Java, but have been a .NET developer for years now and I am a bit confused about the point of the RequestListener object as I can't retrieve the results of my asynchronous calls on the UI thread from what I can tell. My research has told me I should not use singletons or the application context object for getting and storing data. I could use sqlLite, but the data I need is too transient to bother. I would like to know how to have the asyncfacebookrunner object report back it's responses to the UI thread so I can proceed to make decisions between my own api and the objects returned to me from the facebook calls I am making in the async calls. Am I missing something? I can't seem to find a way to get data out. I can pass a Bundle in, but I'm not too sure how to get data out. I would think I would pass it an Intent object to retrieve, but I am not seeing it. I think my eyes are crossed from lack of sleep at this point. Any help here?

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• JavaScript: When does JavaScript evaluate a function, onload or when the function is called?

  - by Benj

  When does JavaScript evaluate a function? Is it on page load or when the function is called? The reason why I ask is because I have the following code: function scriptLoaded() { // one of our scripts finished loading, detect which scripts are available: var jQuery = window.jQuery; var maps = window.google && google.maps; if (maps && !requiresGmaps.called) { requiresGmaps.called = true; requiresGmaps(); } if (jQuery && !requiresJQuery.called) { requiresJQuery.called = true; requiresJQuery(); } if (maps && jQuery && !requiresBothJQueryGmaps.called) { requiresBothJQueryGmaps.called = true; requiresBothJQueryGmaps(); } } // asynch download of script function addScript(url) { var script = document.createElement('script'); script.src = url; // older IE... script.onreadystatechange=function () { if (this.readyState == 'complete') scriptLoaded.call(this); } script.onload=scriptLoaded; document.getElementsByTagName('head')[0].appendChild(script); } addScript('http://google.com/gmaps.js'); addScript('http://jquery.com/jquery.js'); // define some function dependecies function requiresJQuery() { // create JQuery objects } function requiresGmaps() { // create Google Maps object, etc } function requiresBothJQueryGmaps() { ... } What I want to do is perform asynchronous download of my JavaScript and start at the earliest possible time to begin executing those scripts but my code has dependencies on when the scripted have been obviously downloaded and loaded. When I try the code above, it appears that my browser is still attempting to evaluate code within my require* functions even before those functions have been called. Is this correct? Or am I misunderstanding what's wrong with my code?

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• Adding dynamic content with events in jquerymobile

  - by Christian Waidner

  Currently I'm stuck with a problem in jquerymobile: I'm adding items to a list dynamically and use enhanceWithin() in the end (so styling is correct). After this I like to add click-events for each list item but the problem is, that enhanceWithin runs asynchronous and so I always get the error message "cannot call methods on checkboxradio prior to initialization; attempted to call method 'refresh'" When I delay the event-adding-code it works perfectly. Does anyone have an idea if there is a enhanceWithin.done event or anything else I can use? HTML: ... <div id="shoppinglist">Loading list...</div> ... Javascript: function updateList() { var result = ""; $.each(shoppinglistItems, function (index, item) { result += '<label><input type="checkbox" ' + item.checked + ' id="item_' + item.id + '">' + item.name + '</label>\n'; }); $('#shoppinglist').html(result).enhanceWithin(); // Change-Events an die Checkboxen knoten $('input[id*=item_]').unbind('change').bind('change', function (event) { var itemid = $(this).attr('id'); itemid = (itemid.split('_'))[1]; // Nur die Zahl extrahieren // Passendes Item aus der Liste der Items suchen und checken $.each(shoppinglistItems, function (index, item) { if (item.id == itemid) { item.checked = "checked"; item.timestamp = moment().format("YYYYMMDDHHmmss"); } }); updateList(); }); }

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• jQuery trigger custom event synchronously?

  - by Miguel Angelo

  I am using the jQuery trigger method to call an event... but it behaves inconsistently. Sometimes it call the event, sometimes it does not. <a href="#" onclick=" $(this).trigger('custom-event'); window.location.href = 'url'; return false; ">text</a> The custom-event has lots of listeners added to it. It is as if the trigger method is not synchronous, allowing the window.location.href be changed before executing the events. And when window.location.href is changed a navigation occurs, interrupting everything. How can I trigger events synchronously? Using jQuery 1.8.1. Thanks! EDIT I have found that the event, when called has a stack trace like this: jQuery.fx.tick (jquery-1.8.1.js:9021) tick (jquery-1.8.1.js:8499) jQuery.Callbacks.self.fireWith (jquery-1.8.1.js:1082) jQuery.Callbacks.fire (jquery-1.8.1.js:974) jQuery.speed.opt.complete (jquery-1.8.1.js:8991) $.customEvent (myfile.js:28) This proves that jQuery trigger method is asynchronous. Oohhh my... =\

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• IRP_MJ_WRITE latency up to 15 seconds

  - by racitup

  We have written an application that performs small (22kB) writes to multiple files at once (one thread performing asynchronous queued writes to multiple locations on behalf of other threads) on the same local volume (RAID1). 99.9% of the writes are low-latency but occasionally (maybe every minute or two) we get one or two huge latency writes (I have seen 10 seconds and above) without any real explanation. Platform: Win2003 Server with NTFS. Monitoring: Sysinternals Process Monitor (see link below) and our own application logging. We have tried multiple things to try and solve this that have been gleaned from a few websites, e.g.: Making the first part of file names unique to aid 8.3 name generation Writing files to multiple directories Changing Intel Disk Write Caching Windows File/Printer Sharing Minimize memory used Balance Maximize data throughput for file sharing Maximize data throughput for network applications System-Advanced-Performance-Advanced NtfsDisableLastAccessUpdate - use fsutil behavior set disablelastaccess 1 disable 8.3 name generation - use "fsutil behavior set disable8dot3 1" + restart Enable a large size file system cache Disable paging of the kernel code IO Page Lock Limit Turn Off (or On) the Indexing Service But nothing seems to make much difference. There's a whole host of things we haven't tried yet but we wondered if anyone had come across the same problem, a reason and a solution (programmatic or not)? We can reproduce the problem using IOMeter and a simple setup: Start IOMeter and remove all but the first worker thread in 'Topology' using the disconnect button. Select the Worker thread and put a cross in the box next to the disk you want to use in the Disk Targets tab and put '2000000' in Maximum Disk Size (NOTE: must have at least 1GB free space; sector size is 512 bytes) Next create a new access specification and add it to the worker thread: Transfer Request Size = 22kB 100% Sequential Percent of Access Spec = 100% Percent Read/Write = 100% Write Change Results Display Update Frequency to 5 seconds, Test Setup Run Time to 20 seconds and both 'Number of Workers to Spawn Automatically' settings to zero. Select the Worker Thread in the Topology panel and hit the Duplicate Worker button 59 times to create 60 threads with identical settings. Hit the 'Go' button (green flag) and monitor the Results tab. The 'Maximum I/O Response Time (ms)' always hits at least 3500 on our machine. Our machine isn't exactly slow (Xeon 8 core rack server with 4GB and onboard RAID). I'd be interested to see what other people get. We have a feeling it might be something to do with the NTFS filesystem (ours is currently 75% full of fragmented files) and we are going to try a few things around this principle. But it is also related to disk performance since we don't see it on a RAMDisk and it's not as severe on a RAID10 array. Any help is much appreciated. Richard Right-click and select 'Open Link in New Tab': ProcMon Result

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• Is real-time or synchronous replication possible over WAN link?

  - by johnnyb10

  The company I work for is looking to implement truly real-time file replication with file locking over a WAN link that spans over 2000 miles. We currently have a 16-drive SAN setup in our east coast office. We also have an office out in Colorado that will have the same exact SAN setup. The idea is to have those two SANs contain the same exact data at all times, which will allow us to work with the same data pool, and which will also provide use with an offsite backup solution, should a failure occur on either end. We're running Server 2008. The objective is to enable users in the east coast office to work on files and have those changes be instantly updated on the Colorado SAN as well. We also need there to be file locking so that there will be no conflicts or overwritten changes if users attempt to work on the same file. Is this scenario even possible, at speeds that would make the files usable? And if so, what software would we need to pull this off? As I understand it, DFS-R does not provide file locking, so if we used that, we would need to go with a third-party product like Peerlock. But I don't even know if DFS-R is an option. Can it replicate quickly enough over a WAN link? Can any product? It seems that if we were to use synchronous replication, the programs would be unacceptably slow, as every write would have to wait for confirmation from the other end of the link. But if we used asynchronous replication, what kind of latency would we be looking at? There is a product from GlobalScape called WAFS that claims to provide "File coherence with real-time file locking, file release, and synchronization" and says that "As files are modified, changes are mirrored instantly using intelligent byte-level differencing to minimize the impact on network bandwidth". So this sounds like synchronous replication, but that doesn't even seem possible, given physical limitations such as the speed of light. If anyone has any experience with this kind of setup, or knows whether it's even possible, I'd appreciate your input and suggestions, including recommendations for software that we should check out.

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• New MySQL Cluster 7.3 Previews: Foreign Keys, NoSQL Node.js API and Auto-Tuned Clusters

  - by Mat Keep

  At this weeks MySQL Connect conference, Oracle previewed an exciting new wave of developments for MySQL Cluster, further extending its simplicity and flexibility by expanding the range of use-cases, adding new NoSQL options, and automating configuration. What’s new: Development Release 1: MySQL Cluster 7.3 with Foreign Keys Early Access “Labs” Preview: MySQL Cluster NoSQL API for Node.js Early Access “Labs” Preview: MySQL Cluster GUI-Based Auto-Installer In this blog, I'll introduce you to the features being previewed. Review the blogs listed below for more detail on each of the specific features discussed. Save the date!: A live webinar is scheduled for Thursday 25th October at 0900 Pacific Time / 1600UTC where we will discuss each of these enhancements in more detail. Registration will be open soon and published to the MySQL webinars page MySQL Cluster 7.3: Development Release 1 The first MySQL Cluster 7.3 Development Milestone Release (DMR) previews Foreign Keys, bringing powerful new functionality to MySQL Cluster while eliminating development complexity. Foreign Key support has been one of the most requested enhancements to MySQL Cluster – enabling users to simplify their data models and application logic – while extending the range of use-cases for both custom projects requiring referential integrity and packaged applications, such as eCommerce, CRM, CMS, etc. Implementation The Foreign Key functionality is implemented directly within the MySQL Cluster data nodes, allowing any client API accessing the cluster to benefit from them – whether they are SQL or one of the NoSQL interfaces (Memcached, C++, Java, JPA, HTTP/REST or the new Node.js API - discussed later.) The core referential actions defined in the SQL:2003 standard are implemented: CASCADE RESTRICT NO ACTION SET NULL In addition, the MySQL Cluster implementation supports the online adding and dropping of Foreign Keys, ensuring the Cluster continues to serve both read and write requests during the operation.  This represents a further enhancement to MySQL Cluster's support for on0line schema changes, ie adding and dropping indexes, adding columns, etc.  Read this blog for a demonstration of using Foreign Keys with MySQL Cluster.  Getting Started with MySQL Cluster 7.3 DMR1: Users can download either the source or binary and evaluate the MySQL Cluster 7.3 DMR with Foreign Keys now! (Select the Development Release tab). MySQL Cluster NoSQL API for Node.js Node.js is hot! In a little over 3 years, it has become one of the most popular environments for developing next generation web, cloud, mobile and social applications. Bringing JavaScript from the browser to the server, the design goal of Node.js is to build new real-time applications supporting millions of client connections, serviced by a single CPU core. Making it simple to further extend the flexibility and power of Node.js to the database layer, we are previewing the Node.js Javascript API for MySQL Cluster as an Early Access release, available for download now from http://labs.mysql.com/. Select the following build: MySQL-Cluster-NoSQL-Connector-for-Node-js Alternatively, you can clone the project at the MySQL GitHub page.  Implemented as a module for the V8 engine, the new API provides Node.js with a native, asynchronous JavaScript interface that can be used to both query and receive results sets directly from MySQL Cluster, without transformations to SQL. Figure 1: MySQL Cluster NoSQL API for Node.js enables end-to-end JavaScript development Rather than just presenting a simple interface to the database, the Node.js module integrates the MySQL Cluster native API library directly within the web application itself, enabling developers to seamlessly couple their high performance, distributed applications with a high performance, distributed, persistence layer delivering 99.999% availability. The new Node.js API joins a rich array of NoSQL interfaces available for MySQL Cluster. Whichever API is chosen for an application, SQL and NoSQL can be used concurrently across the same data set, providing the ultimate in developer flexibility.  Get started with MySQL Cluster NoSQL API for Node.js tutorial MySQL Cluster GUI-Based Auto-Installer Compatible with both MySQL Cluster 7.2 and 7.3, the Auto-Installer makes it simple for DevOps teams to quickly configure and provision highly optimized MySQL Cluster deployments – whether on-premise or in the cloud. Implemented with a standard HTML GUI and Python-based web server back-end, the Auto-Installer intelligently configures MySQL Cluster based on application requirements and auto-discovered hardware resources Figure 2: Automated Tuning and Configuration of MySQL Cluster Developed by the same engineering team responsible for the MySQL Cluster database, the installer provides standardized configurations that make it simple, quick and easy to build stable and high performance clustered environments. The auto-installer is previewed as an Early Access release, available for download now from http://labs.mysql.com/, by selecting the MySQL-Cluster-Auto-Installer build. You can read more about getting started with the MySQL Cluster auto-installer here. Watch the YouTube video for a demonstration of using the MySQL Cluster auto-installer Getting Started with MySQL Cluster If you are new to MySQL Cluster, the Getting Started guide will walk you through installing an evaluation cluster on a singe host (these guides reflect MySQL Cluster 7.2, but apply equally well to 7.3 and the Early Access previews). Or use the new MySQL Cluster Auto-Installer! Download the Guide to Scaling Web Databases with MySQL Cluster (to learn more about its architecture, design and ideal use-cases). Post any questions to the MySQL Cluster forum where our Engineering team and the MySQL Cluster community will attempt to assist you. Post any bugs you find to the MySQL bug tracking system (select MySQL Cluster from the Category drop-down menu) And if you have any feedback, please post them to the Comments section here or in the blogs referenced in this article. Summary MySQL Cluster 7.2 is the GA, production-ready release of MySQL Cluster. The first Development Release of MySQL Cluster 7.3 and the Early Access previews give you the opportunity to preview and evaluate future developments in the MySQL Cluster database, and we are very excited to be able to share that with you. Let us know how you get along with MySQL Cluster 7.3, and other features that you want to see in future releases, by using the comments of this blog.

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• Some New .NET Toys (Repost)

  - by Kevin Grossnicklaus

  Last week I was fortunate enough to spend time in Redmond on Microsoft’s campus for the 2011 Microsoft MVP Summit. It was great to hang out with a number of old friends and get the opportunity to talk tech with the various product teams up at Microsoft. The weather wasn’t exactly sunny but Microsoft always does a great job with the Summit and everyone had a blast (heck, I even got to run the bases at SafeCo field) While much of what we saw is covered under NDA, there a ton of great things in the pipeline from Microsoft and many things that are already available (or just became so) that I wasn’t necessarily aware of. The purpose of this post is to share some of the info I learned on resources and tools available to .NET developers today. Please let me know if you have any questions (or if you know of something else cool which might benefit others). Enjoy! Visual Studio 2010 SP1 Microsoft has issued the RTM release of Visual Studio 2010 SP1. You can download the full SP1 on MSDN as of today (March 10th to the general public) and take advantage of such things as: Silverlight 4 is included in the box (as opposed to a separate install) Silverlight 4 Profiling WCF RIA Services SP1 Intellitrace for 64-bit and SharePoint ASP.NET now easily supports IIS Express and SQL CE Want a description of all that’s new beyond the above biased list (which arguably only contains items I think are important)? Check out this KB article. Portable Library Tools CTP Without much fanfare Microsoft has released a CTP of a new add-in to Visual Studio 2010 which simplifies code sharing between projects targeting different runtimes (i.e. Silverlight, WPF, Win7 Phone, XBox). With this Add-In installed you can add a new project of type “Portable Library” and specify which platforms you wish to target. Once that is done, any code added to this library will be limited to use only features which are common to all selected frameworks. Other projects can now reference this portable library and be provided assemblies custom built to their environment. This greatly simplifies the current process of sharing linked files between platforms like WPF and Silverlight. You can find out more about this CTP and how it works on this great blog post. Visual Studio Async CTP Microsoft has also released a CTP of a set of language and framework enhancements to provide a much more powerful asynchronous programming model. Due to the focus on async programming in all types of platforms (and it being the ONLY option in Silverlight and Win7 phone) a move towards a simpler and more understandable model is always a good thing. This CTP (called Visual Studio Async CTP) can be downloaded here. You can read more about this CTP on this blog post. MSDN Code Samples Gallery Microsoft has also launched new code samples gallery on their MSDN site: http://code.msdn.microsoft.com/. This site allows you to easily search for small samples of code related to a particular technology or platform. If a sample of code you are looking for is not found, you can request one via the site and other developers can see your request and provide a sample to the site to suit your needs. You can also peruse requested samples and, if you find a scenario where you can provide value, upload your own sample for the benefit of others. Samples are packaged into the VS .vsix format and include any necessary references/dependencies. By using .vsix as the deployment mechanism, as samples are installed from the site they are kept in your Visual Studio 2010 Samples Gallery and kept for your future reference. If you get a chance, check out the site and see how it is done. Although a somewhat simple concept, I was very impressed with their implementation and the way they went about trying to suit a need. I’ll definitely be looking there in the future as need something or want to share something. MSDN Search Capabilities Another item I learned recently and was not aware of (that might seem trivial to some) is the power of the MSDN site’s search capabilities. Between the Code Samples Gallery described above and the search enhancements on MSDN, Microsoft is definitely investing in their platform to help provide developers of all skill levels the tools and resources they need to be successful. What do I mean by the MSDN search capability and why should you care? If you go to the MSDN home page (http://msdn.microsoft.com) and use the “Search MSDN with Big” box at the very top of the page you will see some very interesting results. First, the search actually doesn’t just search the MSDN library it searches: MSDN Library All Microsoft Blogs CodePlex StackOverflow Downloads MSDN Magazine Support Knowledgebase (I’m not sure it even ends there but the above are all I know of) Beyond just searching all the above locations, the results are formatted very nicely to give some contextual information based on where the result came from. For example, if a keyword search returned results from CodePlex, each row in the search results screen would include a large amount of information specific to CodePlex such as: Looking at the above results immediately tells you everything from the page views to the CodePlex ratings. All in all, knowing that this much information is indexed and available from a single search location will lead me to utilize this as one of my initial searches for development information.

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• Goodby jQuery Templates, Hello JsRender

  - by SGWellens

  A funny thing happened on my way to the jQuery website, I blinked and a feature was dropped: jQuery Templates have been discontinued. The new pretender to the throne is JsRender. jQuery Templates looked pretty useful when they first came out. Several articles were written about them but I stayed away because being on the bleeding edge of technology is not a productive place to be. I wanted to wait until it stabilized…in retrospect, it was a serendipitous decision. This time however, I threw all caution to the wind and took a close look at JSRender. Why? Maybe I'm having a midlife crisis; I'll go motorcycle shopping tomorrow. Caveat, here is a message from the site: Warning: JsRender is not yet Beta, and there may be frequent changes to APIs and features in the coming period. Fair enough, we've been warned. The first thing we need is some data to render. Below is some JSON formatted data. Typically this will come from an asynchronous call to a web service. For simplicity, I hard coded a variable:     var Golfers = [         { ID: "1", "Name": "Bobby Jones", "Birthday": "1902-03-17" },         { ID: "2", "Name": "Sam Snead", "Birthday": "1912-05-27" },         { ID: "3", "Name": "Tiger Woods", "Birthday": "1975-12-30" }         ]; We also need some templates, I created two. Note: The script blocks have the id property set. They are needed so JsRender can locate them.     <script id="GolferTemplate1" type="text/html">         {{=ID}}: <b>{{=Name}}</b> <i>{{=Birthday}}</i> <br />     </script>       <script id="GolferTemplate2" type="text/html">         <tr>             <td>{{=ID}}</td>             <td><b>{{=Name}}</b></td>             <td><i>{{=Birthday}}</i> </td>         </tr>     </script> Including the correct JavaScript files is trivial:     <script src="Scripts/jquery-1.7.js" type="text/javascript"></script>     <script src="Scripts/jsrender.js" type="text/javascript"></script> Of course we need some place to render the output:     <div id="GolferDiv"></div><br />     <table id="GolferTable"></table> The code is also trivial:     function Test()     {         $("#GolferDiv").html($("#GolferTemplate1").render(Golfers));         $("#GolferTable").html($("#GolferTemplate2").render(Golfers));           // you can inspect the rendered html if there are poblems.         // var html = $("#GolferTemplate2").render(Golfers);     } And here's what it looks like with some random CSS formatting that I had laying around.    Not bad, I hope JsRender lasts longer than jQuery Templates. One final warning, a lot of jQuery code is ugly, butt-ugly. If you do look inside the jQuery files, you may want to cover your keyboard with some plastic in case you get vertigo and blow chunks. I hope someone finds this useful. Steve Wellens CodeProject

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• CQRS - Benefits

  - by Dylan Smith

  Thanks to all the comments and feedback from the last post I think I have a better understanding now of the benefits of CQRS (separate from the benefits of Event Sourcing). I’m going to try and sum it up here, and point out some areas where I could still use some advice: CQRS Benefits Sounds like the primary benefit of CQRS as an architecture is it allows you to create a simpler domain model by sucking out everything related to queries. I can definitely see the benefit to this, in general the domain logic related to commands is the high-value behavior in the software, but the logic required to service the queries would add a lot of low-value “noise” to the domain model that would dilute the high-value (command) behavior – sorting, paging, filtering, pre-fetch paths, etc. Also the most appropriate domain structure for implementing commands might not be the most optimal for implementing queries. To paraphrase Greg, this usually results in a domain model that is mediocre at both, piss-poor at one, or more likely piss-poor at both commands and queries. Not only will you be able to simplify your domain model by pulling out all the query logic, but at least a handful of commands in most systems will probably be “pass-though” type commands with little to no logic that just generate events. If these can be implemented directly in the command-handler and never touch the domain model, this allows you to slim down the domain model even more. Also, if you were to do event sourcing without CQRS, you no longer have a database containing the current state (only the domain model would) which makes it difficult (or impossible) to support ad-hoc querying and/or reporting that is common in most business software. Of course CQRS provides some great scalability benefits, not only scalability but I have to assume that it provides extremely low latency for most operations, especially if you have an asynchronous event bus. I know Greg says that you get a 3x scaling (Commands, Queries, Client) of your ability to perform parallel development, but IMHO, it seems like it only provides 1.5x scaling since even without CQRS you’re going to have your client loosely coupled to your domain - which is still a great benefit to be able to realize. Questions / Concerns If all the queries against an aggregate get pulled out to the Query layer, what if the only commands for that aggregate can be handled in a “pass-through” manner with the command handler directly generating events. Is it possible to have an aggregate that isn’t modeled in the domain model? Are there any issues or downsides to this? I know in the feedback from my previous posts it was suggested that having one domain model handling both commands and queries requires implementing a lot of traversals between objects that wouldn’t be necessary if it was only servicing commands. My question is, do you include traversals in your domain model based on the needs of the code, or based on the conceptual domain model? If none of my Commands require a Customer.Orders traversal, but the conceptual domain includes the concept of a set of orders belonging to a customer – should I model that in my domain model or not? I like the idea of using the Query side of the architecture as a place to put junior devs where the risk of them screwing something up has minimal impact. But I’m not sold on the idea that you can actually outsource it. Like I said in one of my comments on my previous post, the code to handle a query and generate DTO’s is going to be dead simple, but the code to process events and apply them to the tables on the query side is going to require a significant amount of domain knowledge to know which events to listen for to update each of the de-normalized tables (and what changes need to be made when each event is processed). I don’t know about everybody else, but having Indian/Russian/whatever outsourced developers have to do anything that requires significant domain knowledge has never been successful in my experience. And if you need to spec out for each new query which events to listen to and what to do with each one, well that’s probably going to be just as much work to document as it would be to just implement it. Greg made the point in a comment that doing an aggregate query like “Total Sales By Customer” is going to be inefficient if you use event sourcing but not CQRS. I don’t understand why that would be the case. I imagine in that case you’d simply have a method/property on the Customer object that calculated total sales for that customer by enumerating over the Orders collection. Then the application services layer would generate DTO’s off of the Customers collection that included say the CustomerID, CustomerName, TotalSales, or whatever the case may be. As long as you use a snapshotting implementation, I don’t see why that would be anymore inefficient in a DDD+Event Sourcing implementation than in a typical DDD implementation. Like I mentioned in my last post I still have some questions about query logic that haven’t been answered yet, but before I start asking those I want to make sure I have a strong grasp on what benefits CQRS provides.  My main concern with the query logic was that I know I could just toss it all into the query side, but I was concerned that I would be losing the benefits of using CQRS in the first place if I did that.  I want to elaborate more on this though with some example situations in an upcoming post.

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• F# for the C# Programmer

  - by mbcrump

  Are you a C# Programmer and can’t make it past a day without seeing or hearing someone mention F#?  Today, I’m going to walk you through your first F# application and give you a brief introduction to the language. Sit back this will only take about 20 minutes. Introduction Microsoft's F# programming language is a functional language for the .NET framework that was originally developed at Microsoft Research Cambridge by Don Syme. In October 2007, the senior vice president of the developer division at Microsoft announced that F# was being officially productized to become a fully supported .NET language and professional developers were hired to create a team of around ten people to build the product version. In September 2008, Microsoft released the first Community Technology Preview (CTP), an official beta release, of the F# distribution . In December 2008, Microsoft announced that the success of this CTP had encouraged them to escalate F# and it is now will now be shipped as one of the core languages in Visual Studio 2010 , alongside C++, C# 4.0 and VB. The F# programming language incorporates many state-of-the-art features from programming language research and ossifies them in an industrial strength implementation that promises to revolutionize interactive, parallel and concurrent programming. Advantages of F# F# is the world's first language to combine all of the following features: Type inference: types are inferred by the compiler and generic definitions are created automatically. Algebraic data types: a succinct way to represent trees. Pattern matching: a comprehensible and efficient way to dissect data structures. Active patterns: pattern matching over foreign data structures. Interactive sessions: as easy to use as Python and Mathematica. High performance JIT compilation to native code: as fast as C#. Rich data structures: lists and arrays built into the language with syntactic support. Functional programming: first-class functions and tail calls. Expressive static type system: finds bugs during compilation and provides machine-verified documentation. Sequence expressions: interrogate huge data sets efficiently. Asynchronous workflows: syntactic support for monadic style concurrent programming with cancellations. Industrial-strength IDE support: multithreaded debugging, and graphical throwback of inferred types and documentation. Commerce friendly design and a viable commercial market. Lets try a short program in C# then F# to understand the differences. Using C#: Create a variable and output the value to the console window: Sample Program. using System;   namespace ConsoleApplication9 {     class Program     {         static void Main(string[] args)         {             var a = 2;             Console.WriteLine(a);             Console.ReadLine();         }     } } A breeze right? 14 Lines of code. We could have condensed it a bit by removing the “using” statment and tossing the namespace. But this is the typical C# program. Using F#: Create a variable and output the value to the console window: To start, open Visual Studio 2010 or Visual Studio 2008. Note: If using VS2008, then please download the SDK first before getting started. If you are using VS2010 then you are already setup and ready to go. So, click File-> New Project –> Other Languages –> Visual F# –> Windows –> F# Application. You will get the screen below. Go ahead and enter a name and click OK. Now, you will notice that the Solution Explorer contains the following: Double click the Program.fs and enter the following information. Hit F5 and it should run successfully. Sample Program. open System let a = 2        Console.WriteLine a As Shown below: Hmm, what? F# did the same thing in 3 lines of code. Show me the interactive evaluation that I keep hearing about. The F# development environment for Visual Studio 2010 provides two different modes of execution for F# code: Batch compilation to a .NET executable or DLL. (This was accomplished above). Interactive evaluation. (Demo is below) The interactive session provides a > prompt, requires a double semicolon ;; identifier at the end of a code snippet to force evaluation, and returns the names (if any) and types of resulting definitions and values. To access the F# prompt, in VS2010 Goto View –> Other Window then F# Interactive. Once you have the interactive window type in the following expression: 2+3;; as shown in the screenshot below: I hope this guide helps you get started with the language, please check out the following books for further information. F# Books for further reading   Foundations of F# Author: Robert Pickering An introduction to functional programming with F#. Including many samples, this book walks through the features of the F# language and libraries, and covers many of the .NET Framework features which can be leveraged with F#.       Functional Programming for the Real World: With Examples in F# and C# Authors: Tomas Petricek and Jon Skeet An introduction to functional programming for existing C# developers written by Tomas Petricek and Jon Skeet. This book explains the core principles using both C# and F#, shows how to use functional ideas when designing .NET applications and presents practical examples such as design of domain specific language, development of multi-core applications and programming of reactive applications.

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• Timeout Considerations for Solicit Response – Part 2

  - by Michael Stephenson

  To follow up a previous article about timeouts and how they can affect your application I have extended the sample we were using to include WCF. I will execute some test scenarios and discuss the results. The sample We begin by consuming exactly the same web service which is sitting on a remote server. This time I have created a .net 3.5 application which will consume the web service using the basichttp binding. To show you the configuration for the consumption of this web service please refer to the below diagram. You can see like before we also have the connectionManagement element in the configuration file. I have added a WCF service reference (also using the asynchronous proxy methods) and have the below code sample in the application which will asynchronously make the web service calls and handle the responses on a call back method invoked by a delegate. If you have read the previous article you will notice that the code is almost the same.   Sample 1 – WCF with Default Timeouts In this test I set about recreating the same scenario as previous where we would run the test but this time using WCF as the messaging component. For the first test I would use the default configuration settings which WCF had setup when we added a reference to the web service. The timeout values for this test are: closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"   The Test We simulated 21 calls to the web service Test Results The client-side trace is as follows:   The server-side trace is as follows: Some observations on the results are as follows: The timeouts happened quicker than in the previous tests because some calls were timing out before they attempted to connect to the server The first few calls that timed out did actually connect to the server and did execute successfully on the server   Test 2 – Increase Open Connection Timeout & Send Timeout In this test I wanted to increase both the send and open timeout values to try and give everything a chance to go through. The timeout values for this test are: closeTimeout="00:01:00" openTimeout="00:10:00" receiveTimeout="00:10:00" sendTimeout="00:10:00"   The Test We simulated 21 calls to the web service   Test Results The client side trace for this test was   The server-side trace for this test was: Some observations on this test are: This test proved if the timeouts are high enough everything will just go through   Test 3 – Increase just the Send Timeout In this test we wanted to increase just the send timeout. The timeout values for this test are: closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:10:00"   The Test We simulated 21 calls to the web service   Test Results The below is the client side trace The below is the server side trace Some observations on this test are: In this test from both the client and server perspective everything ran through fine The open connection timeout did not seem to have any effect   Test 4 – Increase Just the Open Connection Timeout In this test I wanted to validate the change to the open connection setting by increasing just this on its own. The timeout values for this test are: closeTimeout="00:01:00" openTimeout="00:10:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"   The Test We simulated 21 calls to the web service Test Results The client side trace was The server side trace was Some observations on this test are: In this test you can see that the open connection which relates to opening the channel timeout increase was not the thing which stopped the calls timing out It's the send of data which is timing out On the server you can see that the successful few calls were fine but there were also a few calls which hit the server but timed out on the client You can see that not all calls hit the server which was one of the problems with the WSE and ASMX options   Test 5 – Smaller Increase in Send Timeout In this test I wanted to make a smaller increase to the send timeout than previous just to prove that it was the key setting which was controlling what was timing out. The timeout values for this test are: openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:02:30"   The Test We simulated 21 calls to the web service Test Results The client side trace was   The server side trace was Some observations on this test are: You can see that most of the calls got through fine On the client you can see that call 20 timed out but still hit the server and executed fine.   Summary At this point between the two articles we have quite a lot of scenarios showing the different way the timeout setting have played into our original performance issue, and now we can see how WCF could offer an improved way to handle the problem. To summarise the differences in the timeout properties for the three technology stacks: ASMX The timeout value only applies to the execution time of your request on the server. The timeout does not consider how long your code might be waiting client side to get a connection. WSE The timeout value includes both the time to obtain a connection and also the time to execute the request. A timeout will not be thrown as an error until an attempt to connect to the server is made. This means a 40 second timeout setting may not throw the error until 60 seconds when the connection to the server is made. If the connection to the server is made you should be aware that your message will be processed and you should design for this. WCF The WCF send timeout is the setting most equivalent to the settings we were looking at previously. Like WSE this setting the counter includes the time to get a connection as well as the time to execute on a server. Unlike WSE and ASMX an error will be thrown as soon as the send timeout from making your call from user code has elapsed regardless of whether we are waiting for a connection or have an open connection to the server. This may to a user appear to have better latency in getting an error response compared to WSE or ASMX.

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• MySQL Connect Only 10 Days Away - Focus on InnoDB Sessions

  - by Bertrand Matthelié

  Time flies and MySQL Connect is only 10 days away! You can check out the full program here as well as in the September edition of the MySQL newsletter. Mat recently blogged about the MySQL Cluster sessions you’ll have the opportunity to attend, and below are those focused on InnoDB. Remember you can plan your schedule with Schedule Builder. Saturday, 1.00 pm, Room Golden Gate 3: 10 Things You Should Know About InnoDB—Calvin Sun, Oracle InnoDB is the default storage engine for Oracle’s MySQL as of MySQL Release 5.5. It provides the standard ACID-compliant transactions, row-level locking, multiversion concurrency control, and referential integrity. InnoDB also implements several innovative technologies to improve its performance and reliability. This presentation gives a brief history of InnoDB; its main features; and some recent enhancements for better performance, scalability, and availability. Saturday, 5.30 pm, Room Golden Gate 4: Demystified MySQL/InnoDB Performance Tuning—Dimitri Kravtchuk, Oracle This session covers performance tuning with MySQL and the InnoDB storage engine for MySQL and explains the main improvements made in MySQL Release 5.5 and Release 5.6. Which setting for which workload? Which value will be better for my system? How can I avoid potential bottlenecks from the beginning? Do I need a purge thread? Is it true that InnoDB doesn't need thread concurrency anymore? These and many other questions are asked by DBAs and developers. Things are changing quickly and constantly, and there is no “silver bullet.” But understanding the configuration setting’s impact is already a huge step in performance improvement. Bring your ideas and problems to share them with others—the discussion is open, just moderated by a speaker. Sunday, 10.15 am, Room Golden Gate 4: Better Availability with InnoDB Online Operations—Calvin Sun, Oracle Many top Web properties rely on Oracle’s MySQL as a critical piece of infrastructure for serving millions of users. Database availability has become increasingly important. One way to enhance availability is to give users full access to the database during data definition language (DDL) operations. The online DDL operations in recent MySQL releases offer users the flexibility to perform schema changes while having full access to the database—that is, with minimal delay of operations on a table and without rebuilding the entire table. These enhancements provide better responsiveness and availability in busy production environments. This session covers these improvements in the InnoDB storage engine for MySQL for online DDL operations such as add index, drop foreign key, and rename column. Sunday, 11.45 am, Room Golden Gate 7: Developing High-Throughput Services with NoSQL APIs to InnoDB and MySQL Cluster—Andrew Morgan and John Duncan, Oracle Ever-increasing performance demands of Web-based services have generated significant interest in providing NoSQL access methods to MySQL (MySQL Cluster and the InnoDB storage engine of MySQL), enabling users to maintain all the advantages of their existing relational databases while providing blazing-fast performance for simple queries. Get the best of both worlds: persistence; consistency; rich SQL queries; high availability; scalability; and simple, flexible APIs and schemas for agile development. This session describes the memcached connectors and examines some use cases for how MySQL and memcached fit together in application architectures. It does the same for the newest MySQL Cluster native connector, an easy-to-use, fully asynchronous connector for Node.js. Sunday, 1.15 pm, Room Golden Gate 4: InnoDB Performance Tuning—Inaam Rana, Oracle The InnoDB storage engine has always been highly efficient and includes many unique architectural elements to ensure high performance and scalability. In MySQL 5.5 and MySQL 5.6, InnoDB includes many new features that take better advantage of recent advances in operating systems and hardware platforms than previous releases did. This session describes unique InnoDB architectural elements for performance, new features, and how to tune InnoDB to achieve better performance. Sunday, 4.15 pm, Room Golden Gate 3: InnoDB Compression for OLTP—Nizameddin Ordulu, Facebook and Inaam Rana, Oracle Data compression is an important capability of the InnoDB storage engine for Oracle’s MySQL. Compressed tables reduce the size of the database on disk, resulting in fewer reads and writes and better throughput by reducing the I/O workload. Facebook pushes the limit of InnoDB compression and has made several enhancements to InnoDB, making this technology ready for online transaction processing (OLTP). In this session, you will learn the fundamentals of InnoDB compression. You will also learn the enhancements the Facebook team has made to improve InnoDB compression, such as reducing compression failures, not logging compressed page images, and allowing changes of compression level. Not registered yet? You can still save US$ 300 over the on-site fee – Register Now!

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• The illusion of Competence

  - by tony_lombardo

  Working as a contractor opened my eyes to the developer food chain.  Even though I had similar experiences earlier in my career, the challenges seemed much more vivid this time through.  I thought I’d share a couple of experiences with you, and the lessons that can be taken from them. Lesson 1: Beware of the “funnel” guy.  The funnel guy is the one who wants you to funnel all thoughts, ideas and code changes through him.  He may say it’s because he wants to avoid conflicts in source control, but the real reason is likely that he wants to hide your contributions.  Here’s an example.  When I finally got access to the code on one of my projects, I was told by the developer that I had to funnel all of my changes through him.  There were 4 of us coding on the project, but only 2 of us working on the UI.  The other 2 were working on a separate application, but part of the overall project.  So I figured, I’ll check it into SVN, he reviews and accepts then merges in.  Not even close.  I didn’t even have checkin rights to SVN, I had to email my changes to the developer so he could check those changes in.  Lesson 2: If you point out flaws in code to someone supposedly ‘higher’ than you in the developer chain, they’re going to get defensive.  My first task on this project was to review the code, familiarize myself with it.  So of course, that’s what I did.  And in familiarizing myself with it, I saw so many bad practices and code smells that I immediately started coming up with solutions to fix it.  Of course, when I reviewed these changes with the developer (guy who originally wrote the code), he smiled and nodded and said, we can’t make those changes now, it’s too destabilizing.  I recommended we create a new branch and start working on refactoring, but branching was a new concept for this guy and he was worried we would somehow break SVN. How about some concrete examples? I started out by recommending we remove NUnit dependency and tests from the application project, and create a separate Unit testing project.  This was met with a little bit of resistance because - “How do I access the private methods?”  As it turned out there weren’t really any private methods that weren’t exposed by public methods, so I quickly calmed this fear. Win 1 Loss 0 Next, I recommended that all of the File IO access be wrapped in Using clauses, or at least properly wrapped in try catch finally.  This recommendation was accepted.. but never implemented. Win 2  Loss 1 Next recommendation was to refactor the command pattern implementation.  The command pattern was implemented, but it wasn’t really necessary for the application.  More over, the fact that we had 100 different command classes, each with it’s own specific command parameters class, made maintenance a huge hassle.  The same code repeated over and over and over.  This recommendation was declined, the code was too fragile and this change would destabilize it.  I couldn’t disagree, though it was the commands themselves in many cases that were fragile. Win 2 Loss 2 Next recommendation was to aid performance (and responsiveness) of the application by using asynchronous service calls.  This on was accepted. Win 2 Loss 3 If you’re paying any attention, you’re wondering why the async service calls was scored as a loss.. Let me explain.  The service call was made using the async pattern.  Followed by a thread.sleep  <facepalm>. Now it’s easy to be harsh on this kind of code, especially if you’re an experienced developer.  But I understood how most of this happened.  One junior guy, working as hard as he can to build his first real world application, with little or no guidance from anyone else.  He had his pattern book and theory of programming to help him, but no real world experience.  He didn’t know how difficult it would be to trace the crashes to the coding issues above, but he will one day.  The part that amazed me was the management position that “this guy should be a team lead, because he’s worked so hard”.  I’m all for rewarding hard work, but when you reward someone by promoting them past the point of their competence, you’re setting yourself and them up for failure.  And that’s lesson 3.  Just because you’ve got a hard worker, doesn’t mean he should be leading a development project.  If you’re a junior guy busting your ass, keep at it.  I encourage you to try new things, but most importantly to learn from your mistakes.  And correct your mistakes.  And if someone else looks at your code and shows you a laundry list of things that should be done differently, don’t take it personally – they’re really trying to help you.  And if you’re a senior guy, working with a junior guy, it’s your duty to point out the flaws in the code.  Even if it does make you the bad guy.  And while I’ve used “guy” above, I mean both men and women.  And in some cases mutant dinosaurs. 

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• Some New .NET Downloads and Resources

  - by Kevin Grossnicklaus

  Last week I was fortunate enough to spend time in Redmond on Microsoft’s campus for the 2011 Microsoft MVP Summit.  It was great to hang out with a number of old friends and get the opportunity to talk tech with the various product teams up at Microsoft.  The weather wasn’t exactly sunny but Microsoft always does a great job with the Summit and everyone had a blast (heck, I even got to run the bases at SafeCo field) While much of what we saw is covered under NDA, there a ton of great things in the pipeline from Microsoft and many things that are already available (or just became so) that I wasn’t necessarily aware of.  The purpose of this post is to share some of the info I learned on resources and tools available to .NET developers today.  Please let me know if you have any questions (or if you know of something else cool which might benefit others). Enjoy! Visual Studio 2010 SP1 Microsoft has issued the RTM release of Visual Studio 2010 SP1.  You can download the full SP1 on MSDN as of today (March 10th to the general public) and take advantage of such things as: Silverlight 4 is included in the box (as opposed to a separate install) Silverlight 4 Profiling WCF RIA Services SP1 Intellitrace for 64-bit and SharePoint ASP.NET now easily supports IIS Express and SQL CE Want a description of all that’s new beyond the above biased list (which arguably only contains items I think are important)?  Check out this KB article. Portable Library Tools CTP Without much fanfare Microsoft has released a CTP of a new add-in to Visual Studio 2010 which simplifies code sharing between projects targeting different runtimes (i.e. Silverlight, WPF, Win7 Phone, XBox).   With this Add-In installed you can add a new project of type “Portable Library” and specify which platforms you wish to target.  Once that is done, any code added to this library will be limited to use only features which are common to all selected frameworks.  Other projects can now reference this portable library and be provided assemblies custom built to their environment.  This greatly simplifies the current process of sharing linked files between platforms like WPF and Silverlight.  You can find out more about this CTP and how it works on this great blog post. Visual Studio Async CTP Microsoft has also released a CTP of a set of language and framework enhancements to provide a much more powerful asynchronous programming model.   Due to the focus on async programming in all types of platforms (and it being the ONLY option in Silverlight and Win7 phone) a move towards a simpler and more understandable model is always a good thing. This CTP (called Visual Studio Async CTP) can be downloaded here.  You can read more about this CTP on this blog post. MSDN Code Samples Gallery Microsoft has also launched new code samples gallery on their MSDN site: http://code.msdn.microsoft.com/.   This site allows you to easily search for small samples of code related to a particular technology or platform.  If a sample of code you are looking for is not found, you can request one via the site and other developers can see your request and provide a sample to the site to suit your needs.  You can also peruse requested samples and, if you find a scenario where you can provide value, upload your own sample for the benefit of others.  Samples are packaged into the VS .vsix format and include any necessary references/dependencies.  By using .vsix as the deployment mechanism, as samples are installed from the site they are kept in your Visual Studio 2010 Samples Gallery and kept for your future reference. If you get a chance, check out the site and see how it is done.  Although a somewhat simple concept, I was very impressed with their implementation and the way they went about trying to suit a need.  I’ll definitely be looking there in the future as need something or want to share something. MSDN Search Capabilities Another item I learned recently and was not aware of (that might seem trivial to some) is the power of the MSDN site’s search capabilities.  Between the Code Samples Gallery described above and the search enhancements on MSDN, Microsoft is definitely investing in their platform to help provide developers of all skill levels the tools and resources they need to be successful. What do I mean by the MSDN search capability and why should you care? If you go to the MSDN home page (http://msdn.microsoft.com) and use the “Search MSDN with Big” box at the very top of the page you will see some very interesting results.  First, the search actually doesn’t just search the MSDN library it searches: MSDN Library All Microsoft Blogs CodePlex StackOverflow Downloads MSDN Magazine Support Knowledgebase (I’m not sure it even ends there but the above are all I know of) Beyond just searching all the above locations, the results are formatted very nicely to give some contextual information based on where the result came from.  For example, if a keyword search returned results from CodePlex, each row in the search results screen would include a large amount of information specific to CodePlex such as: Looking at the above results immediately tells you everything from the page views to the CodePlex ratings.  All in all, knowing that this much information is indexed and available from a single search location will lead me to utilize this as one of my initial searches for development information.

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