DotNetKicks.com : Stories kicked by oazabir

MemoryStream Multiplexer - Write and Read from many threads

Wed, 04 Apr 2012 15:01:33 GMT

Here's an implementation of MemoryStream like buffer manager where one thread can write and many threads can read simultaneously. Each reading thread gets its own reader and can read from the shared stream on its own without blocking write operation or other parallel read operations. It supports blocking Read call so that reader threads can call Read(.) and wait until some data is available, exactly the same way you would expect a Stream to behave.

Cache WCF Javascript Proxy on Browser

Sat, 07 Apr 2012 05:41:03 GMT

When you use WCF services from Javascript, you have to generate the Javascript proxies by hitting the Service.svc/js. If you have five WCF services, then it means five javascripts to download. As browsers download javascripts synchronously, one after another, it adds latency to page load and slows down page rendering performance. Moreover, the same WCF service proxy is downloaded from every page, because the generated javascript file is not cached on browser. Here is a solution that will ensure the generated Javascript proxies are cached on browser and when there is a hit on the service, it will respond with HTTP 304 if the Service.svc file has not changed.

Prevent ASP.NET cookies from being sent on every css, js, img request

Sun, 16 Oct 2011 02:54:35 GMT

ASP.NET generates some large cookies if you are using ASP.NET membership provider. Especially if you are using the Anonymous provider, then a typical site will send 517 bytes of cookie on every css, js, image request. That's 60 GB worth useless upload for 1M page view. See how to prevent this.

Tweaking WCF to build highly scalable async REST API

Sun, 31 Jul 2011 16:43:54 GMT

You can build async REST API using WCF but due to some bug in WCF implementation it does not scale as you would want it to. Here's my journey with Microsoft's WCF team to explore the problem and find the right fix.

Build truly RESTful API and website using same ASP.NET MVC code

Fri, 29 Jul 2011 23:32:52 GMT

Usually we create separate controllers or WCF service layer to deal with API part of the website but I will show you how you can create both RESTful website and API using the same controller code working over the exact same URL that a browser can use to browse through the website and a client application can do CRUD over.

Automatic JS, CSS versioning to force update browser cache

Sun, 29 May 2011 17:25:30 GMT

When you update javascript or css files that are already cached in users' browsers, most likely many users won't get that for some time because of the caching at the browser or intermediate proxy(s). You need some way to force browser and proxy(s) to download latest files. Here's an HttpFilter that will automatically generate new URL for changed files.

WCF does not support compression out of the box, so fix it

Sat, 26 Feb 2011 23:18:54 GMT

WCF does not support compression over IIS. Even IIS does not support compression of SOAP messages by default. Learn how to fix both.

Safely deploying changes to production server

Fri, 25 Feb 2011 17:50:45 GMT

When you deploy incremental changes on a production server, which is running and live all the time, you some times see error messages like "Compiler Error Message: The Type 'XXX' exists in both.". Sometimes you find Application_Start event not firing although you shipped a new class, dll or web.config. Sometimes you find static variables not getting initialized and so on. There are so many weird things happen on webservers when you incrementally deploy changes to the server and the server has been up and running for several weeks. Learn how to safely deploy and automate server restart, cleanup, start, warmup procedures.

Quick ways to boost performance and scalability of ASP.NET, WCF and De

Sun, 05 Dec 2010 20:50:29 GMT

By tweaking system.net changes, you can increase the number of parallel calls that can be made from the services hosted on your servers as well as on desktop computers and thus increase scalability. By changing WCF throttling config you can increase number of simultaneous calls WCF can accept and thus make most use of your hardware power. By changing ASP.NET process model, you can increase number of concurrent requests that can be served by your website. And finally by turning on IIS caching and dynamic compression, you can dramatically increase the page download speed on browsers and and overall responsiveness of your applications.

Dynamically set WCF Endpoint in Silverlight

Sun, 05 Dec 2010 16:40:45 GMT

When you add a WCF service reference to a Silverlight Application, it generates the ServiceReference.ClientConfig file where the URL of the WCF endpoint is defined. When you add the WCF service reference on a development computer, the endpoint URL is on localhost. But when you deploy the Silverlight client and the WCF service on a production server, the endpoint URL no longer is on localhost instead on some domain. As a result, the Silverlight application fails to call the WCF services. You have to manually change the endpoint URL on the Silverlight config file to match the production URL before deploying live. See how to automate this.

Ten Caching mistakes that break your app

Sat, 09 Oct 2010 03:00:52 GMT

Caching frequently used objects, that are expensive to fetch from the source, makes application perform faster under high load. It helps scale an application under concurrent requests. But some hard to notice mistakes can lead the application to suffer under high load, let alone making it perform better, especially when you are using distributed caching where there's separate cache server or cache application that stores the items. Moreover, code that works fine using in-memory cache can fail when the cache is made out-of-process. Here I will show you some common distributed caching mistakes that will help you make better decision when to cache and when not to cache.

How to make screencasts in animated GIF for free

Fri, 24 Sep 2010 05:40:05 GMT

I have been using animated GIFs to show short screencasts in my blogs and articles. Animated GIF is supported by all browsers and supports virtually any website in the world where even Flash is blocked. A picture is worth a thousand words, and an animation is worth a thousand multiplied by [frames in animation] words. So, I have been looking for a complete free solution to capturing screencasts and then converting it to animated GIF and then heavily compressing it.

Building High Performance Queue in Database for Orders, Tasks, ...

Sun, 19 Sep 2010 09:03:05 GMT

Queue is a widely used data structure that sometimes have to be created in a database instead of using specialized queue technologies like MSMQ. Running a high performance and highly scalable queue using database technologies is a big challenge and it's hard to maintain when the queue starts to get millions of rows queued and dequeued per day. Let me show you some common design mistakes made in designing Queue-like tables and how to get maximum performance and scalability from a queue implemented using simple database features.

Exporting normalized relational data from database to flat file

Sun, 29 Aug 2010 17:12:41 GMT

Sometimes you need to export relational normalized data into flat files where a single row comes from various tables. For example, say you want to export all customer records along with their work and home address, and primary phone number in a single row. But the address and contact information are coming from different tables and there can be multiple rows in those table for a single customer. Sometimes there can be no row available in address/phone table for a customer. In such a case, neither INNER JOIN, nor LEFT JOIN/OUTER JOIN will work. How do you do it? Solution is to use OUTER APPLY.

Website diagnostic page to diagnose your ASP.NET app

Tue, 24 Aug 2010 11:37:51 GMT

Whenever you change web.config file or deploy your website on a new environment, you have to try out many relevant features to confirm if the configuration changes or the environment is correct. Sometimes you have to run a smoke test on the website to confirm if the site is running fine. Moreover, if some external database, webservice or network connectivity is down, it takes time to nail down exactly where the problem is. Having a self-diagnostics page on your website like the one you see on your printer can help identify exactly where's the problem. Here's a way how you can quickly create a simple self-diagnostics page in a single page without spending too much effort. This diagnostics page tests for common configuration settings like connection string, ASP.NET Membership configurations, SMTP settings, <appSettings> file paths and URLs items and some application specific settings to confirm if the changes are all correct.

WatiN to automate browser and test complex AJAX websites

Fri, 06 Aug 2010 15:30:37 GMT

WatiN is a great .NET library for writing automated browser based tests that uses real browser to go to websites, perform actions and check for browser output. Combined with a unit test library like xUnit, you can use WatiN to perform automated regression tests on your websites and save many hours of manual testing every release. Moreover, WatiN can be used to stress test Javascripts on the page as it can push the browser to perform operations repeatedly and measure how long it takes for Javascripts to run. Thus you can test your Javascripts for performance, rendering speed of your website and ensure the overall presentation is fast and smooth for users.

Munq is for Web, Unity is for Enterprise

Tue, 18 May 2010 05:22:12 GMT

The Unity Application Block (Unity) is a lightweight extensible dependency injection container with support for constructor, property, and method call injection. It's a great library for facilitating Inversion of Control and the recent version supports AOP as well. However, when it comes to performance, it's CPU hungry. In fact it's so CPU hungry that it makes it impossible to make it work at Internet Scale. Thus comes Munq, a super fast Container for the web.

Finally! Entity Framework 100% Unit Testable and N-tier capable

Tue, 18 May 2010 04:57:54 GMT

Learn how I have produced a 100% unit testable fully n-tier compliant data access layer following the repository pattern using Entity Framework solving all the "gotchas" out there.

Tips and Tricks to rescue overdue projects

Mon, 03 May 2010 10:59:02 GMT

A story of a typical offshore project which is overdue, customer shouting and screaming, offshore guys working day and night and how we brainstormed on some tricks to get out of this.

How to convince developers and management to use automated test

Mon, 03 May 2010 10:54:54 GMT

Learn ways to convince devs and management to move away from manual testing to automated unit, integration testing. See some convincing graphs to put in a powerpoint.

Redirecting traffic from http to https with zero coding in IIS

Sat, 17 Apr 2010 15:10:23 GMT

When you want to enforce https on users and you want to redirect any URL being hit on http to the exact counterpart of https, then usually you do it with some HttpModule written in .NET, or install some URL Redirector module in IIS, or setup a dummy website on http and then use meta refresh tag to send traffic to https. There are many solutions out there which requires some amount of coding skill. Let me show you a zero coding redirection setup.

PlantUML Editor: A fast and simple UML editor using WPF

Tue, 16 Mar 2010 14:45:00 GMT

A WPF client to design UML diagrams at the speed of coding. Forget all mouse based designers. This is the future of UML diagram design.

Memory Leaks with delegates and workflows

Tue, 09 Mar 2010 05:27:29 GMT

Learn how to detect and solve memory leaks caused by delegates and workflow foundation

Do both Unit Test and Integration Test from same test code

Mon, 01 Mar 2010 06:01:40 GMT

Using Conditional Compilation, you can write test code once but make it do both unit tests using mocking as well as integration tests with all the wires connected. Learn the BDD way of doing both unit and integration test in one shot.

Fast,Scalable,Streaming AJAX Proxy-deliver data from external domains

Mon, 22 Feb 2010 05:28:23 GMT

Regular proxies download the whole content on server and then deliver to browser. This streaming proxy streams content directly from the source and thus outperforms any regular proxy. Moreover it implement Async Handler to be more scalable.