Disclaimer : This post is an opinion piece and I am not speaking on behalf of Microsoft or our HR department. In the past, Microsoft interviews involved riddles or brainteasers and were a source of anxiety for interview candidates. These are questions...

Not too long ago, Microsoft released two free games for Windows Phone 7: Sudoku and Minesweeper. More info here: http://www.winrumors.com/sudoku-and-minesweeper-released-for-windows-phone-7/ The Sudoku app has this notion of "power-ups" which are little...

From the perspective of a WCF developer, the interaction between WCF and ASP.NET can be a black box. But to understand the performance of a system, it is necessary to know how all the components interact. This post covers how threads work when a request...

Our team just got back from a fun trip to Portland, OR to attend the Portland Code Camp . Glenn Block did a great job of putting this together and it was an exciting opportunity to meet developers outside of the Microsoft bubble. A fairly large group...

The WCF Web API is a pretty exciting new offering from our team. The simplicity of creating and consuming a service is quite compelling. Especially considering that you can take advantage of the infrastructure surrounding HTTP and the web. One of the...

A few customers have noticed an issue with WCF scaling up when handling a burst of requests. Fortunately, there is a very simple workaround for this problem that is covered in KB2538826 (thanks to David Lamb for the investigation and write up). The KB...

There has been a lot of uproar over Red Gate's recent decision to charge for the .Net Reflector tool. As a Microsoft employee that spends a lot of time with performance and debugging tools, Reflector is essential. When Red Gate bought the rights to Reflector...

WCF services that are hosted in IIS can take advantage of compression without making any special encoder changes . In Windows Server 2008 R2, IIS compression is actually turned on by default and WCF as of .Net 4.0 supports decompression by default. So...

Last night I ran into an issue where I couldn't print from IE9. However, I could print from other programs. If the webpage initiated the print, then I got the following script error: Line: 2107 Char: 1 Error: Invalid procedure call or argument...

The "Server too busy" error is a common one that causes a lot of confusion when related to WCF. It is possible for WCF to respond with a server too busy fault when a quota is exceeded in the security layer. However you wouldn't get this when you hit a...

WCF performance has many aspects. In the previous series I explored how using GZip/Deflate compression can increase performance in areas with low network latency. However, the penalty is that the CPU utilization is much higher. Therefore, it does not...

The aim of compressing the messages sent from a WCF service is to reduce the amount of traffic on the wire. You could be doing this because you're in a hosted environment such as a cloud service and you have to pay for bandwidth. The tradeoff for compression...

In this post, I will run a client and service with the GZipMessageEncoder on the same machine and analyze the performance. The WCF sample application for GZipMessageEncoder has been suitable up until now for functional testing. For performance testing...

The GZipMessageEncoder is a great sample for learning about MessageEncoders in general. In this post, I will expand the GZipMessageEncoder to do both GZip and Deflate compression. This will accomplish two things: (1) explain various pieces of a MessageEncoder...

The compression options for WCF out of the box are limited in .Net 4.0. However, a sample is provided for GZip compression that shows you how to write your own MessageEncoder that can wrap the output of another encoder and apply GZip to the messages....

The StreamUpgradeProvider in WCF is not a well-known extension point. Nicholas Allen has a great set of blog posts describing how to use this. You can start reading that with this post: http://blogs.msdn.com/b/drnick/archive/2006/09/07/stream-upgrades_2c00_...

Part of the performance enhancements made in WF4 are in the size of the workflow instance state. There are a number of contributing design decisions: Separation of workflow definition from workflow instance - I like to think of this as the separation...

Microsoft has offered employees free Windows Phone 7 phones. This means a lot of people around the office are carrying them now. Before that, if there was any one most popular device it was the iPhone. I also had a first-gen iPhone before switching to...

Custom activities that perform long-running work can affect workflow performance in unexpected ways. Understanding WF's threading model and scheduler can help activity authors make informed decisions about their code. This post intends to shed some light...

When writing custom activities for WF4, the latest revision of Windows Workflow, new to the .Net 4.0 Framework, you can cut some performance costs by overriding the CacheMetadata method. By default, CacheMetadata will use reflection to determine what...

The ServiceModel performance counters can tell you how many concurrent calls, instances, and sessions you have. In .Net 4.0, more counters were added to tell you how close you are to the throttles for each of those categories. So if you're trying to performance...

In the previous article, we began analyzing the first portion of the timeline, which is where IIS starts up the process. In this, I pointed out that 16% of the sampled time was spent in page faults. Sampling does not always give us the whole story though...

Back in the early days of AppFabric, when it was still just Dublin and Velocity, a demo was given to the management team that started with a simple xamlx workflow. You can probably imagine the concern as a room full of managers silently waited for this...

I recently received this error when trying to use the Native VHD boot feature of Windows 7: The configuration for an element within the object is invalid in the boot configuration data store. There are a few things that could cause this but I suspect...

This is one of the first issues I got to investigate on the WCF/WF performance team. Customers reported that (in .Net 3.5 and earlier), the first asynchronous call from a WCF client was taking over 1 second each time, even with synchronous calls happening...