.NET From India

Wait for an Asynchronous Method

The async and await pattern is a great way to ease asynchronous programming in .NET 4.5. When using await and the whole calling stack is not async (maybe it has no need to be), you will have to sometime forced to wait for a async method to finish before proceeding and not want to use await, because the current method is not async.

It is not very easy to find how to do this as most examples around async/await only. So how do you work with an async method without using await.

I am waiting a example using the Live SDK, which is full of async APIs like most libraries now a days

   1:   Dim LoginTask As Task(Of LiveLoginResult) = _AuthContext.LoginAsync(scope)

   2:   LoginTask.Wait(100)

All async methods return a Task or Task<> type. Instead of using await, you can use the above syntax to wait for the async method to finish. The parameter to the Wait call is the timeout value. If that is not used, then the application will wait indefinitely for the task to end.

SOAP, REST and Other Protocols

Whether you understand SOA or not, this is a buzzword that is here to stay. One of the side effects of this is that every architect and developer worth his/her salt is recommending and building web services (which is synonymous with SOA even if it is strictly not so)

So one of the main decisions you need to take as a designer/architect is on the different protocols you can choose from for implementing web services. There is obviously SOAP and the huge set of supporting standards to choose from (all the WS-** standards). Then there is the new kid (relatively..) on the block REST..

So one of the criteria to look at is the performance impact of these standards. Note, this is one of the criteria and there may be multiple others to consider based on your particular needs.

When I was searching the internet for details, I found few actual measures on the performance impact of these protocols (it was a near universal claim that REST was faster than SOAP, but rarely any data to back this up). Especially there was almost no data on the impact of these different protocols when implemented using WCF and .NET.

So I setup a test project to check out the performance impact of these. The idea was to measure the difference in performance of these protocols, removing other factors as far as possible. So I just ran everything on my machine, no network impact, in a single program. Obviously this is not a fully controlled atmosphere and do take the benchmarks with a bit of salt. But this should give you enough data on the relative overheads of each of these protocols.

All this data is based on using WCF with the services hosted in local IIS. The response time I measure is for the entire call to complete from the client (caller) code. So includes going thru the service proxy and for the data to be marshaled back.

I tested the impact when the data transported is small and large. A single int return value is small data and an string array of 100 is the large data.

The initial benchmark data is as follow:

		Client Response Time (ms)
Less Data	SOAP/HTTP - UnSecure	0.37
	SOAP/HTTP - Secure	1.62
	SOAP/HTTPS - UnSecure	0.61
	REST JSON	0.31
	REST XML	0.38
	SOAP - UnSecure - ESB	2.27
	SOAP/TCP UnSecure	0.06
	SOAP/TCP Secure	1.00
More Data	SOAP/HTTP - UnSecure	0.54
	SOAP/HTTP - Secure	3.20
	SOAP/HTTPS - UnSecure	1.01
	REST JSON	0.48
	REST XML	0.54
	SOAP - UnSecure - ESB	3.33
	SOAP/TCP	0.20
	SOAP/TCP - Secure	2.41

 

No brainer here, the TCP SOAP call are the fastest and literally leaves everything else in the dust. No comparison here, if you can use TCP, go for it every time, no confusion on SOAP vs. REST.

When I say Secure/UnSecure above, I am taking about using WS-Security, not HTTPS. I also measure HTTPS impact separately (roughly doubles response time for small data, but is less of an overhead for larger payloads).

Also you see the impact of XML processing in the REST times. REST JSON is faster than REST XML and the overhead here is purely the size of the data passed (more on this later) and the XML processing time.

Also you see the impact of adding more processing by the impact of addition of WS-Security. This is the default WCF binding and if you do not want this you need to choose the wsbasicHTTPbinding.

The other parameter I looked at, though very unscientifically is the size of data that is passed. This becomes even more important when the network is involved.

Data Serialization(Less Data)	Data Size (Bytes)
REST JSON	45
REST XML	215
SOAP – UnSecure	384
SOAP – Secure	5370

So you can see the amount of data overhead due to WS-Security. When very little data is interchanged the overhead can be almost 100 times.

(Also I measured the actual service execution time and that is quite constant for all these. So this is a measure of the performance of the different protocols/standards involved only.)

Technorati Tags: WCF,Benchmark,SOAP,REST,comparison,.NET

Silverlight, HTML 5 and the whole RIA puzzle

Microsoft SilverLight (Photo credit: denetsnuff)

A year or so ago if you are a developer on the MS platform and you wanted to develop an RIA application, you automatically picked Silverlight as option 1. If Silverlight was not viable, then you started looking at other options like ASP.NET AJAX etc. But picking Silverlight was a no brainer.

Then along came HTML 5 and talk around the interactivity, graphics and Offline usage features of HTML 5. At around the same time, Microsoft started to put out kind of confusing messaging around Silverlight. SL 5 was making its way out, but HTML 5 support was also being added. Then Microsoft went silent on the future of Silverlight. That led to talk around SL getting the cut and everything moving to HTML 5.

If you are going to create an application that needs some kind of RIA features or offline, out of browser support, you are now at a decision point. Do you go with Silverlight or jump into HTML 5?

Well this post is my thought process around answering that question…

If you need offline access and do not want to write a desktop app (WinForm or WPF), then HTML 4 kind of gets ruled out. HTML 5 adds support for Offline Scenarios, but this is not fully supported yet. So there is a needs for offline support, as of now, you have only 2 options, a desktop app or Silverlight. (I am going to keep my scope constrained to Microsoft technologies as that is what I work with)

Another usual need is rich interactions (which led to RIA). Obviously currently with technologies like AJAX, JSON and web services, it is possible for HTML applications to be a lot more interactive than before. HTML 5 does take this forward a lot and promises a scenario where you can get really interactive applications running in the browser.

The problem I see with HTML 5 is that if you are planning to build an enterprise application (keeping it simple as you have control on browsers you will support inside the enterprise) then in the short term, if there is a need for offline support or high interactivity, then the only option is Silverlight. Ok, what about support then, since MS is strangely silent on Silverlight's future. Well, Silverlight is supported till 2021, and most enterprise applications have a life time of 5-10 years. So even if SL is going to go out of support in 2021, there is a high chance that you application has already go through a rewrite cycle by this time and you could have chosen an alternative, maybe HTML 5, for the rewrite.

So in the short term, if you are building a new application, then do not ignore Silverlight. It is a very viable option till HTML 5 stabilizes and is widely supported (at the same level by multiple browsers) or by that time, there may be a Silverlight 6, who knows!!

Technorati Tags: Silverlight,HTML 5,Application Development Options

Free VS 2011 Developer Preview Training Kit

If you have started looking into the new Visual Studio 2011 Developer Preview and want to learn more, then you have a training kit from the MS Developer Evangelism team. This includes Presentations, Hands on Labs and other resources to learn what’s new in VS 2011. (including Metro apps)

Visual Studio 11 Developer Preview Training Kit - http://www.microsoft.com/download/en/details.aspx?id=27738

Note: A VHD and set of HOLs covering TFS server and the ALM side of things is also available. Download instructions is available at http://blogs.msdn.com/b/briankel/archive/2011/09/16/visual-studio-11-application-lifecycle-management-virtual-machine-and-hands-on-labs-demo-scripts.aspx

Home Server 2011 Connector and Problems with .NET Framework..

I had setup the new Home Server 2011 on one of my servers and have been transitioning stuff off my Home Server v1.

So after all of the data has been transferred and I had setup the server in a way that makes sense to me (given that Drive Extender, DE, is not there anymore and how much I miss that… That is a completely separate post by itself)

Then I started moving my client machines over. I left my main desktop off till the last and I came to it yesterday.

The Connect installation is quite simple and it just asks around 2-3 simple questions and that’s it. The problem is that they have made it so simple that it becomes very difficult when there is a problem. So the only error the setup reports is a wonderfully descriptive – “The Windows Home Server 2011 Connector has encountered an unexpected error” or something like that (Well everyone knows what an unexpected error is and can easily fix that. Right )..

After some searching, I found an KB article saying that a few services need to be running and I was still getting this error after I confirmed those services were good.

Then I came upon this post on the forum that talks about this problem occurring if a beta .NET 4.0 was installed..

Then it stuck me.. I had installed the VS 2010 Beta on this machine a long time back and then after playing around for a few days, forgotten about that (as I rarely use that machine for any development). So I uninstalled all the pieces that was installed with VS 2010 Beta and then also uninstalled .NET 4.0 Beta.

Only problem was, half way thru the uninstall something happened and my machine blue screened. The Beta disappeared from the Program and Features screen. So I went ahead and installed the full .NET 4.0 RTM. But still Connector will not install. Same Problem as before.

So I tried to uninstall .NET 4.0 RTM thinking I will clean everything and try again. Now it wouldn’t uninstall cleanly. It would go half way and crash. So basically I got stuck with a half installed .NET 4.0.

Then I came upon the .NET cleanup utility. Downloaded the latest version and set it up to clean up .NET 4.0. It actually went half way and then the system re-booted. Not sure if this was the planned way, but when I checked the log, it seemed as if there was an error. So I just ran the utility again and it went through fine.

Then I went and installed the full .NET 4.0 RTM and then the Connector install went thru fine with no problems.

It would have been a lot easier and saved me around 5+ hours if the setup had just said, there was a wrong version of the .NET Framework, instead of the great “unexpected error”…

Moving Applications to Azure

I was reading this post about how they are moving TFS to Azure to provide a cloud based version of TFS.

I find this very interesting as it provides you with a view of what kinds of problems you may face if you are moving an existing application on to the cloud (esp. Azure)

Some issues like security can have a major impact on your application design, while others like SELECT INTO support may also drain a lot of effort to fix.

And the final big thing that may weigh on your overall effort is testing. Because, now all your previous test results are out of the window and you will have to do a complete regression to make sure that everything works find.

Microsoft BI – ‘hard to beat pricewise’ – Forrester

A recent Forrester Report on the BI space puts Microsoft BI on the leaders quadrant and also says the value of Microsoft BI is ‘hard to beat pricewise’.

I have been seeing an increasing trend among customers in adopting Microsoft BI over the past year or so and this seems to be led strongly from two fronts:

1. Price – Since the price of most of the elements required for BI is encapsulated in things that most enterprises already have (SQL Server, SharePoint (for PPS) and Office (Excel+PowerPivot).

2. New UI power in PowerPivot and SharePoint PPS services seem to also add to the overall trend.

(Source : http://blogs.msdn.com/b/ragnarh/archive/2010/10/26/forrester-research-calls-microsoft-s-business-intelligence-value-proposition-hard-to-beat-pricewise.aspx)

Passing an Excel Application Object to .NET COM Object

I was writing .NET component that was COMVisible and aimed at working along with Excel Macros. Instead of creating a VSTO project, I just went with a .NET DLL with Com wrappers.

Actually this is a very viable option, if you just want to automate excel without too much of the support provided by VSTO (which in turn adds its own overhead). So you just reference the Excel Interop and you are set to go.

One of the things I wanted to do was to pass over the current Excel Application object to .NET so that I can interact and do some work from .NET.

So I initially wrote a function like below:

 

    Public Function testParam(ByVal app As Application) As Boolean
	more here code
        Return True
    End Function

If you try to call this function from Excel VBA

x.testparam (Application)

will result in an error at the VBA level “Invalid procedure call or argument”

I have tried to find why this is happening but I don’t see any specific description of why this happens. I did see some pointers where, the InterOp actually uses Interfaces and behind the scenes map the objects to the actual classes. So if you see in Visual Studio you will see the Excel.Application is actually shown as an interface. I suspect this maybe the reason for the error.

The current workaround that works for me is to use a Property to capture the Application object. Though this is the cleanest way (I prefer the parameter in the object I was designing) the property seems to be the only way to get this to work.

So the code will change to

Public Property ExcelApplication As Application

And in the VBA you can just assign to the property as:

x.ExcelApplication = Application

This works fine….

 

Note: I am using VS2010 and .NET 4. So I have taken advantage of Automatic Properties

Memory Mapped Files in .NET 4.0

File manipulations has been something that you have been doing for a long time. It is a integral part of application development. But the approach to doing this has not changed much from the days of Basic.

I came across this article about .NET 4.0 support for Memory mapped files and it does seem interesting and neat way to handle large files (Especially if your application does flat file based import of data etc.).

Working with Large Memory-Mapped Files in VB 2010

Enhanced Data Generator 1.2.0

I have uploaded a new version of the Custom Data Generator Library I am building.

More information is available here and the Download is available here.

Major Changes are

• Seperated out the IBAN Generator to a seperate DLL so as to isolate the usage of the RegExString Class
• Added a new Generator to generate Indian Bank Codes
• Minor bug fixes