Data Binding in Web Test (Web Service Test)

Today I would like to share how to perform parametrized functional test on WCF web service by using Visual Studio 2012.

Note: Only for Visual Studio Test Professional or Ultimate Edition.

First, create a new Web Performance and Load Test Project.

Then, add a new web service request in your web test.

Open up the properties window for the newly created web service request. Enter your WCF service URL in the Url property.

Add a new HTTP header for your web service request. 

Open the properties window for your newly added header. Select the name as SOAPAction.

Then enter the value for the SOAP action. The value is depending on which service operation that you would like to test. The information can be obtained from WSDL.

Open the properties window for String Body. Select the content type as text/xml. Then, enter the SOAP message into the String Body property. If you do not know how to form a proper SOAP message, here is a shortcut tip for you.

Open up WCF Test Client. It is located at C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE\wcftestclient.exe. Or, you can fire up Developer Command Prompt for VS2012 from your all programs list, then enter wcftestclient in the command prompt.

At the My Service Projects, right click it then select Add Service. Enter your WCF service Url, then hit the OK button.

Double click the service operation that you want to test. Fill in all the required values. Then hit the Invoke button.

Click the XML tab at the bottom of the window.

Copy the XML from the Request field. That is the SOAP message that you need to put into the String Body in the web test in Visual Studio.

Go back to Visual Studio, paste the copied XML from the WCF Test Client into the String Body property field. Remove the whole <Action> element from the SOAP Header if the WCF service endpoint is configured with basicHttpBinding which is using SOAP version 1.1.

Hit the OK button, then click the Run Test button to test whether the SOAP message is accepted by the WCF service. You should expect the return is HTTP200 status and expected SOAP message response.

Now, prepare test data for parametrization. Open Microsoft Excel or Notepad to create a comma delimited text file (*.csv). The first row always is the column name, the subsequent rows are the test data.

Go back to Visual Studio, right click the Data Sources folder, click Add Data Source. Enter a data source name, select CSV file, then click Next button. Click the Browse button and choose the CSV file which you had just created with test data.

Open up the String Body property field editor. Replace the value that you want to parametrize with {{DataSourceName.TableName.ColumnName}}.

Open up the Local.testings from the Solution Explorer.

Go to Web Test, choose the radio button "One run per data source row". Click the Apply button, then close the window.

In the web test window, click the Run Test button. You should expect to see multiple run with different request SOAP message.

Exception: Network Access for Distributed Transaction Manager (MSDTC) Has Been Disabled

Quite some time ago, some of the developers complained about an exception had been thrown from the TransactionScope. And, I attempted to troubleshoot the problem with one of the developers together.

Here is the story. The following is the exception detail:

Network access for Distributed Transaction Manager (MSDTC) has been disabled. Please enable DTC for network access in the security configuration for MSDTC using the Component Services Administrative tool.

If you google around, the given solution normally is asking you to make sure the Distribute Transaction Coordinator (DTC) is configured properly and firewall is cleared, but I still get the same exception.

During the troubleshooting process, I found that there were different connection strings being used, which is like this:

<connectionStrings>

  <add name="db1"

       connectionString="server=myServer1;database=myDataBase; uid=myUser;password=myPassword;"

       providerName="System.Data.SqlClient" />

  <add name="db2"

       connectionString="Data Source=myServer2;Initial Catalog=myDataBase;User ID=myUser;Password=myPassword;"

       providerName="System.Data.SqlClient" />

</connectionStrings>

The developer went on to change one of the connection string to make them using the same format. The result is no more exception had been thrown.

This is weird and went on to search for the difference between these 2 connection string. Base on the article from MSDN - http://msdn.microsoft.com/en-us/library/jj653752(v=vs.110).aspx, they are synonymous with each other. But, DTC does not treat them the same. I do not know why and how TransactionScope internal work. Perhaps, you tell me why if you come across this page and know the answer.

Conclusion, the above exception message is rather useless and sound like a common error message for anything which is related to DTC. Do not just check your DTC configuration, but also check your connection strings.

UPDATE ADD-ON:

There are some people asking more about how to troubleshoot this error. Besides the connection string issue stated as above, there are actually more thing to check:

1. Firewall

Please ensure that you have unblock the firewall for DTC in all related web server and database server.

Inbound Rule:

Outbound Rule:

2. DTC Windows Service

Make sure the Distributed Transaction Coordinator service is running in all related web server and database server.

3. Hostname Resolve

Make sure all the server hostname are able to be resolved in all related web server and database server. Either update the DNS server and then flush the DNS cache by executing ipconfig.exe /flushdns command or add in hostname in the host file manually which is located at C:\Windows\System32\drivers\etc\hosts.

For instance, you have a web server and two database server. Web server must be able to ping both database servers with server name instead of IP address. The database server must be able to ping the web server and the other database server too by pinging both servers hostname.

4. Configure MSDTC Security

Run the command dcomcnfg, then expand the Component Services all the way down to Distributed Transaction Coordinator. Right click the Local DTC, then click the Properties.

Enable the Network DTC Access and remain the default configuration.