Dariusz quatscht : English Posts

Visual Studio 2010 - Fun with DynamicObject in C# 4.0

dparys — Thu, 22 Oct 2009 08:09:38 GMT

This morning I just played around with the new C# 4.0 dynamic feature. Using the dynamic keyword allows you to bind to properties, indexers and methods during runtime. This means that during compile time there is no check if the methods, properties or...(read more)

CREATE DATABASE permission denied in database ‘master’ – My Fix

dparys — Thu, 17 Sep 2009 11:29:32 GMT

Normally I always install SQL Management Studio for my development environment. But this time I just thought I would not need it. I installed my machine outside of the domain network. The SQL Server 2008 Express installation was done with a local administrator user which I enabled to have dbo admin rights. I have also given rights for the local administrators group in SQL Server Express. After joining the domain I added my domain account to the local adminstrators group. Everything looked good. So I just started SQLCMD and tried to attach the AdventureWorksLT database (from Codeplex). This error came up.

CREATE DATABASE permission denied in database ‘master’.

Hmm? Oh, I forgot that UAC stuff.

Why do I write this post? My first reaction was to search the internet for exactly the title of this blog post to find the CREATE LOGIN description in a step by step solution and was shocked by the results I retrieved. Mostly people talking in Forums about this just work around security with granting the hosting process unlimited rights like local system for the sql server engine or the IIS App Pool. My 9th hit on the list had a reasonable explanation on how to add a login but was using SQL Management Studio which I don’t want to use right now. The post is not a real step by step guide, it is just the steps needed in my scenario to enable the user to create, delete and work with a lot of temporary databases.

How to check your current login?

First open up SQLCMD and check with select user_name() if you are not logged in as guest (like in my case). I could omit the problem with elevating the SQLCMD process – as I’m in the local administrators group and would get dbo rights – but I wanted to give the user dedicated rights without elevating the whole process each time. Further, my main task with my domain user regarding this SQL Server instance is creating and working with a lot of databases.

Adding a domain account as sysadmin to SQL Express with SQLCMD

The following steps show how to add a domain account using SQLCMD and give this user sysadmin rights.

Start SQLCMD with an authorized account

In my case I had already my domain account in the local administrators group and assigned the local administrators group to the SQL Server dbo group during installation. To get the right token when starting SQLCMD I just had to start it elevated.

Start a command shell elevated
type SQLCMD –S (local)\sqlexpress

It depends on the database instance name how the server is specified. In the example above I use my local machine and the instance is called SQLEXPRESS.

Create the login

First create a SQL Server login for your domain account.

CREATE LOGIN [your domain account] FROM WINDOWS;

your domain account has to be replaced with the domain account you want to add. For instance your domain is called darth and the user vader than it would be CREATE LOGIN [darth\vader] FROM WINDOWS; GO;

To check if the login was successfully created type in

SELECT NAME FROM SYS.SERVER_PRINCIPALS

and the domain user should appear in the result list.

Grant sysadmin rights

You can retrieve a list of server roles using the sp_helpsrvrole procedure. So to add the user to the sysadmin server role group type the following (example is still domain darth user vader)

SP_ADDSRVROLEMEMBER ‘darth\vader’, ‘sysadmin’

Done.

Quit SQLCMD and open a non elevated instance with your domain account. Type in select user_name() and the result should be dbo.

Disclaimer

I have to write that I don’t run any production environments on my machine. With giving my user sysadmin rights, even when not elevated, I open up attack surface through SQL Server. Therefore here the big disclaimer

Big disclaimer: In a production environment I do not recommend giving full dbo rights to a dedicated user account. Please ensure the login just gets the rights he really needs to do the work. Check also the site SQL Server Best Practices.

Improving Entity Framework Performance

dparys — Mon, 06 Apr 2009 10:48:20 GMT

I was really shocked when I saw this blog post: Entity Framework and LINQ to SQL Performance. I decided to download the performance test solution and try the tests myself. I did not changed any of the tests so far, I just added for my own interest NHibernate into the game as I think that it is the choice of Frameworks for Domain Driven Design.

So, I was shocked again, as I saw my numbers in the chart:

The elapsed time was 4 times higher than with plain SqlDataReader. But more worse was the fact the the elapsed processor time was nearly 8 times higher. NHibernate was really good in performance compared to Entity Framework, but LINQ to SQL was still better.

What was wrong? I couldn’t imagine that we had such an issue in data access using the Entity Framework. I took a look at the code. All test runs are looping 10000 times over the access method to retrieve the customers data. In this loop, each time a connection will be created and closed. Linq to SQL and Linq to Entities are using compiled queries, so, this optimization was already done. I also added in my tests a pre-generated Entity Framework view (using edmgen.exe) to enhance startup performance. Still those poor results.

Here is the original code from the tests:

   1: public static List<CustomerResults> GetCustomers()

   2: {

   3:     using (NorthwindEntities ne = new NorthwindEntities())

   4:     {

   5:         return GetCustomersQuery(ne).ToList();

   6:     }

   7: }

8:

   9: private static Func<NorthwindEntities, IQueryable<CustomerResults>>

  10:     GetCustomersQuery = CompiledQuery.Compile(

  11:         (NorthwindEntities ne) => from c in ne.Customers

  12:                                   select new CustomerResults

  13:                                   {

  14:                                       CustomerID = c.CustomerID,

  15:                                       CompanyName = c.CompanyName,

  16:                                       ContactName = c.ContactName,

  17:                                       ContactTitle = c.ContactTitle,

  18:                                       City = c.City,

  19:                                       Country = c.Country

  20:                                   });

My guess was that the instantiation of the connection string could be the problem. Why? Because several things happen here. First, the EntityConnection which is created when not specifying any argument in the constructor of the typed object context class NorthwindEntities, has to read from the config file. I/O cost. Second, it has to read the metadata information, which is stored by default in the assembly as resource. Second performance cost. Here is my optimization approach. One of the overload constructors is taking an EntityConnection object. Guess what, you probably just use this one connection object during the whole life time of your application, so why not create it once and give it into the constructor. This does not mean that I open the connection beforehand, no, I just create the type EntityConnection and retrieve the meta information in the first call. From that, I reuse this instance, so no need anymore to retrieve the metadata information again.

Here is the optimization in my code base:

   1: private static EntityConnection entityConnection;

2:

   3: public static void InitializeConnectionString()

   4: {

   5:     SqlConnectionStringBuilder sqlBuilder = new SqlConnectionStringBuilder();

   6:     sqlBuilder.DataSource = @"(local)\sqlexpress";

   7:     sqlBuilder.InitialCatalog = "NorthwindPerfTest";

   8:     sqlBuilder.IntegratedSecurity = true;

   9:     sqlBuilder.MultipleActiveResultSets = true;

10:

11:

  12:     EntityConnectionStringBuilder builder = new EntityConnectionStringBuilder();

  13:     builder.Provider = "System.Data.SqlClient";

  14:     builder.Metadata = "res://*/Customers.csdl|" +

  15:                        "res://*/Customers.ssdl|" +

  16:                        "res://*/Customers.msl";

  17:     builder.ProviderConnectionString = sqlBuilder.ToString();

18:

  19:     entityConnection = new EntityConnection(builder.ToString());

  20: }

I have a static variable entityConnection which holds the reference on the object. In the constructor I just pass this reference:

   1: public static List<CustomerResults> GetCustomers()

   2: {

   3:     using (NorthwindEntities ne = new NorthwindEntities(entityConnection))

   4:     {

   5:         return GetCustomersQuery(ne).ToList();

   6:     }

   7: }

Now I have difference numbers to show in my chart:

For this specific test scenario I cutted performance cost two times for the elapsed time and four times for the process elapsed time. Hope that helps.

Coding 4 Fun: Slide Tweet 0.1

dparys — Tue, 10 Feb 2009 17:24:05 GMT

What is Slide Tweet? A Powerpoint Add-In twittering slide titles. If you are not familiar with http://twitter.com I suggest to read the post “How to Twitter – First Steps and a Twitter Glossary” from Scott Hanselman. Why do I want to have an add-in for powerpoint twittering slide titles? Well, I had an idea and I will test it in the next talk I give. The idea is simpel to integrate the audience through Twitter while presenting content.

People can follow the tag specified in the beginning of the presentation and make comments, retweet or discuss the slide topic presented currently. Maybe I will use this to answer questions coming through twitter during the presentation, I’m not sure yet.

Here are some screenshots how this works. First you load any powerpoint you want to present and start the presentation. After this you will be asked if you want to twitter this deck.

After specifying credentials and the tag to use for the tweets, you are ready to go. During presentation slide titles will be twittered with the specified tag. The audience is able to follow this tag. Let’s assume we have a tag which is called #gac09. You can basically follow this tag using the twitter search functionality or any other twitter client able to search for tags.

The results will be shown and refreshed if new content for this tag is available.

You will see all tweets using the tag and not only the tweets by your presentation but also any tweets using the tag, replying on your tweets.

The audience could interact among each other and give also feedback via Twitter (at least this is the idea I had). That said, it makes sense to specify one or multiple tags to make the presentation unique (please no UUID).

I will see how it works on my next talk.

If you are a presenter and would like to try out this add-in you can. I have posted a resource page on my code gallery with the solution file: Slide Tweet. Please note that you need Visual Studio 2008 and Visual Studio Tools for Office and Powerpoint 2007 to run this sample. I have no really good setup so far, neither good error handling. Therefore enjoy with care.

One design decision I made. I always call to Twitter asynchronously with one exception. The last slide is posted synchronously, just to ensure that every call was made (so I even don’t utilize the callbacks).

Have fun and feedback welcome!

Giving my account rights to create service endpoints on port 80

dparys — Fri, 23 Jan 2009 09:04:16 GMT

Note to myself: new OS, missing configuration:

Start command shell in administration mode
netsh http add urlacl url=http://+:80/ user=DOMAIN\user

Update: If you are doing this, your local IIS might not be able to display websites on port 80. See this post: Service Unavailble HTTP Error 503 mit IIS 7 auf Windows 7

How to find and install the Live Framework SDK (CTP)

dparys — Thu, 30 Oct 2008 16:23:26 GMT

It is not easy to find the Live Framework SDK introduced during PDC 2008. Therefore I just snapshot and wrote down the steps to find and install it.

Apply for the Live Framework SDK

This is something you should do first. If you are at PDC 2008 you have an alternative way of doing the Hands-on Lab and getting so the activation code. If you are not at PDC 2008 you will find the link through http://dev.live.com/liveframework

Fill out the form and wait until you get an approval email. BTW, I still don’t got mine, I took the shortcut going through the HOL.

Redeem your activation token

If you received your activation token, you have to redeem it. This will be done on http://lx.azure.microsoft.com.

You have to go through the registration. If you have already an Live Applications it will find it and make it manageable throught the portal. Next, you will enter the activation token and redeem it.

If the token was valid you receive the following message

Creating a Project

The following is not clearly described. You have to go through creating a project to get the Live Framework SDK and its dependencies.

If you go “New Project” in the upper left corner, you will be starting the project creation process. Select “Live Services: Live Framework Community Technology Preview”. Note, that you have a maximum amount of 25 projects to test with.

After selecting you have to read and accept the Terms of Use in order to receive the SDK. Next, type in the project name and description

And now we got where we want to be. We received the link!

The link will navigate you to the Mesh CTP where you can host a Mesh-Enabled application and have the links for the download packages

Installing the Live Framework SDK

It is important to install in order, first Live Framework SDK, then Silverlight Tools for Visual Studio and finally Live Framework Tools for Microsoft Visual Studio. One thing to mention is that the Live Framework SDK just comes in a zipped form. You have to copy the content to your Program Files directory into the Microsoft SDK folder. Beware that you need UAC elevation on Vista when enabled, what I’m sure you have!

After that you are ready to run the Silverlight Tools installer and close the whole process with the Live Framework tools.

Done

The result in Visual Studio 2008

Happy Meshing!

How to install the Nortwind sample database in SQL Server Express

dparys — Wed, 23 Jul 2008 12:43:57 GMT

One of the things when setting up an demo environment (a fresh install) is to integrate the Northwind sample database on the demo environment. I normally just use a SQL Server Express for demos and I take Northwind to have data to play with, what else. I know there is some discussion around Northwind, but I for myself know that anyone in the audience knows Northwind, so no need to explain 15 valueable minutes on a more complex Schema.

So a blank SQL Server Express install on my machine is taking me to the following steps:

Download the Northwind sample database from download.microsoft.com
Run the Setup with the default settings. On my box the installed directory is "c:\SQL Server 2000 Sample Databases"
Open a Command Prompt
Change to the script directory, in my case cd "c:\sql server 2000 sample databases"
Execute the following command:
sqlcmd -S (local)\sqlexpress -E -i instnwnd.sql
(assuming that your SQL Server Express is installed with default settings which is the named instance SQLEXPRESS)

That's it. Northwind is now installed on SQL Server Express.

Twitter WCF 3.5 API Library

dparys — Wed, 04 Jun 2008 08:44:24 GMT

I just published the API declaration library, even it is just experimental and has not been tested. I think it is still a time saver to get at least the declarations. If anyone has an improved version, I would be interested to be updated. You can find the library here and some more info here.

The library just wraps the Twitter API described here.

Programming Twitter with WCF 3.5

dparys — Mon, 02 Jun 2008 09:39:36 GMT

Do you Twitter? If so, this could be of interest for you. If not, maybe you are interested in how to use the Twitter REST API to write own client applications.

Imagine you could just use Twitter from your code like this:

   1: TwitterStatusProxy proxy = new TwitterStatusProxy( "username", "password" );

2:

   3: // retrieve friends timeline

   4: XElement timeline = proxy.GetFriendsTimeline();

5:

   6: // do whatever you want to do with the data

I just wrote up a demo for a security talk I gave last friday, using the Twitter API from WCF 3.5. One interesting scenario using Twitter, beside its origin to update the current status of the user, is to integrate the pub/sub system with SMS capabilities into an application. Imagine, you have a bunch of field workers on the road and they could just update status information on ongoing business via the Twitter infrastructure or the way back from the central to the field workers. You receive status information via SMS and are up to date. This scenario is especially interesting in Countries where SMS costs are still high. You have up to 250 SMS per week when using Twitter (in the US, I think there is not this limit). Could be a huge amount of money to spare. Ok, there is of course one drawback, the reliability of the plattform. I have no idea how well it scales if it is under pressure and how often downtimes are. Meanwhile you have an API call to get informed about planned downtime slots.

Anyway, I want to show you how to use Twitter with WCF 3.5. Here we go. Twitters API is almost an authenticated one, this means for most calls you have to authenticate yourself before calling into the API. Therefore I have chosen to always provide a username and password in the constructor of the proxy class. I decided also to use for each category an own proxy implementation. Of course, I created a base class to inherit (similar to ClientBase, less functionality) from and all proxies are using this class. My last decision was not to model data contracts or value objects. I decided just to leave it as an XElement, this has the advantage that anyone is free to provide own mapping objects on top of the proxy.

Here is the generic base proxy class

   1: public abstract class TwitterProxyBase<T>

   2: {

   3:     protected T proxy;

   4:     protected readonly string twitterBaseUri = "https://twitter.com";

5:

   6:     protected TwitterProxyBase( string username, string password )

   7:     {

   8:         this.CreateProxy( username, password );

   9:     }

10:

  11:     protected void CreateProxy( string username, string password )

  12:     {

  13:         WebHttpBinding binding = new WebHttpBinding();

  14:         binding.Security.Mode = WebHttpSecurityMode.Transport;

  15:         binding.Security.Transport.ClientCredentialType = HttpClientCredentialType.Basic;

16:

  17:         ChannelFactory<T> channel = new ChannelFactory<T>(

  18:             binding,

  19:             this.twitterBaseUri );

20:

  21:         channel.Endpoint.Behaviors.Add( new WebHttpBehavior() );

22:

  23:         channel.Credentials.UserName.UserName = username;

  24:         channel.Credentials.UserName.Password = password;

25:

  26:         proxy = channel.CreateChannel();

  27:     }

  28: }

No error handling in my code, as I just wrote that one for the demo, you should include Error-handling. From this base class you just have to inherit and write a little proxy helper. In general I'm using the WCF 3.5 WebGet and WebInvoke attributes to decorate the proxy interface. This is how the Status API interface of Twitter looks in WCF decorated. I just shortened the class for more clarity.

   1: [ServiceContract]

   2: public interface ITwitterStatusXml

   3: {

   4:     // serveral operations missing for clarity

5:

   6:     [OperationContract]

   7:     [WebGet( UriTemplate = "/statuses/friends_timeline.xml",

   8:              BodyStyle = WebMessageBodyStyle.Bare,

   9:              ResponseFormat = WebMessageFormat.Xml )]

  10:     XElement GetFriendsTimeline();

11:

  12:     [OperationContract]

  13:     [WebGet( UriTemplate = "/statuses/friends_timeline/{screenName}.xml",

  14:              BodyStyle = WebMessageBodyStyle.Bare,

  15:              ResponseFormat = WebMessageFormat.Xml )]

  16:     XElement GetFriendsTimelineByScreenName( string screenName );

17:

  18:     [OperationContract]

  19:     [WebInvoke( UriTemplate = "/statuses/update.xml?status={status}",

  20:                 Method = "POST",

  21:                 BodyStyle = WebMessageBodyStyle.Bare,

  22:                 ResponseFormat = WebMessageFormat.Xml )]

  23:     XElement Update( string status );

  24: }

Line 7-10 and 12-16 are demonstrating GET operations on the Twitter contract, where line 18-23 are showing a POST.

Now the proxy inherits the base class and this interface.

   1: public class TwitterStatusProxy : TwitterProxyBase<ITwitterStatusXml>, ITwitterStatusXml

   2: {

   3:     public TwitterStatusProxy( string username, string password )

   4:         : base( username, password )

   5:     {

   6:     }

7:

   8:     #region ITwitterStatusXml Members

9:

  10:     // most operations not included for more clarity

11:

  12:     public XElement GetFriendsTimeline()

  13:     {

  14:         return proxy.GetFriendsTimeline();

  15:     }

16:

  17:     public XElement GetFriendsTimelineByScreenName( string screenName )

  18:     {

  19:         return proxy.GetFriendsTimelineByScreenName( screenName );

  20:     }

21:

22:

  23:     public XElement Update( string status )

  24:     {

  25:         string encodedStatus = AntiXss.HtmlEncode( status );

  26:         if( encodedStatus.Length > 160 )

  27:         {

  28:             throw new ArgumentException( "Status information may not exceed 160 characters" );

  29:         }

  30:         return proxy.Update( encodedStatus );

  31:     }

32:

  33:     #endregion

  34: }

That's it

Now you can use Twitter from your application like I showed in the beginning. For instance to update the users status is as easy as to write

   1: TwitterStatusProxy proxy = new TwitterStatusProxy( "username", "password" );

2:

   3: XElement result = proxy.Update( "currently testing twitter" );

If you are interested into the interface declarations for the whole Twitter API, send me an email at dparys add microsoft dot com. I will send you the C# project. Why this way, why not sharing? Because I have not tested the complete API declaration. I wrote those API during a train ride with no internet access and had no chance to test. Its up to you. Feedback welcome!

Yet Another Windows Live Demo Video

dparys — Fri, 09 May 2008 15:06:39 GMT

Daniel Walzenbach and myself are demoing Windows Live with all its possibilities. In this scenario we have a mom, missing her son, but she always knows where he is! How this magic works, see and guess who is playing Daniel's mom? Enjoy!

Visual C++ Event in Bad Homburg, Germany

dparys — Wed, 02 Apr 2008 10:10:50 GMT

On April, 17th we have Boris Jabes from the Visual C++ Product Team in Germany. This Community Event is free of charge and will have the following Agenda:

Agenda Community Event

What's new in Visual Studio 2008

walkthrough new C++ features
VSTS for C++ developers

A deeper look into the VS2008 Feature Pack for C++

demo of improvements to MFC
the value of TR1

A brief glimpse into the future of Visual C++

highlights from what we're building for the next version of C++

The event will be from 4pm - 7pm. This is an excellent opportunity to get in touch with the Visual C++ Product Team. If you have any questions, any suggestions or just things you don't know how to proceed, come and join our community event. I guess Boris is also the perfect discussion partner when it comes to Intellisense inside Visual C++.

To sign up for the event, just klick this link and write at least your contact details down.

Fast Facts:

Date: 17.04.2008

Time: 4pm - 7pm

Location: Steigenberger Hotel Bad Homburg, Kaiser-Friedrich-Promenade 69-75, 61348 Bad Homburg v. d. Höhe

Directions here

About Boris Jabes

Boris Jabes is a program manager on the Visual C++ team. He is responsible for improving the IDE experience for C++ developers with a focus on furthering the quality of source editing, understanding, and analysis. Recently, he's been concentrating on making the IDE scale to multi-million line source bases. Before joining Microsoft, Boris obtained degrees from the University of Waterloo and Carnegie Mellon where he specialized in distributed systems and software engineering.

Blog: http://blogs.msdn.com/borisj

Of course, we are expecting at least as much people as on the launch event in February, the video below. Ok, we had about 7.000 Attendees so I guess we can live with a few less. Sorry for the wrong ratio, I recorded it with 16:9 but it seems that Silverlight Streaming is encoding regardless in 4:3.

Hope to see you on the Visual C++ 2008 Community Event in Bad Homburg.

Mambo speed run install - Check this out!

dparys — Wed, 16 Jan 2008 16:00:50 GMT

My colleque Bernhard "TigerDuck" Frank has created an amazing video about the Raktajino project. I did a podcast in December with him (just in German) and we discussed what Tigerduck in general is. So, if you want to see, how you can install Mambo , without...(read more)

Evangelism Jamboree, I'm looking forward for the next one

dparys — Mon, 03 Dec 2007 12:40:46 GMT

Today was our first Evangelism Jamboree among France, United Kingdom and Germany. It is actually the first time I met some Evangelist from France and UK (ok, I met the architects two weeks ago in Prague) and it was a really interesting conversation we...(read more)

World of Warcraft - Popfly Mashup

dparys — Fri, 30 Nov 2007 13:54:46 GMT

Due to the new World of Warcraft Patch, leveling from 20-60 became much easier. Therefore I think I will give it a try and would like to level up a Warlock, had none so far. By the way, this was done with Microsoft Popfly....(read more)

Ale Contenti on the new MFC Update (Video)

dparys — Thu, 29 Nov 2007 19:28:05 GMT

Two weeks ago we had Steve Teixeira and Ale Contenti in Germany. As we have recorded nearly every session of them, I just thought that this one might be of interest for all you folks who are awaiting the new MFC Update which is coming first half of 2008....(read more)