Loading WebServices With JMETER

Apache JMeter is a 100% pure Java desktop application designed to load test client/server software. JMeter can be used to simulate a heavy load on a server, network or object to test its strength or to analyze overall performance under different load types.

Additionally, JMeter can help you regression test your application by letting you create test scripts by putting assertions to validate that the application is returning the results that are expected.

 Web Services can be easily loaded and it s performance measured using JMeter. The typical steps for load testing using JMeter is as follows:

1) Create a test plan

2) Add a Thread Group

3) Add a WebSerice Request

4) Apply Assertions on the response

5) View results

Creating a Test Plan

In the default test plan that appears on opening the JMeter UI (from JMeter.bat in the bin directory) set the option of 'Functional Test Mode' as true. You may also want to add user defined variables. However for this example I will not be using any user defined variable.

Add a Thread Group

Add a Thread Group element by right clicking the test plan node and selecting 'Add-->Threads (Users)-->Thread Group'

Adding Thread Group

Set the number of threads in the provided section and set the Ramp-up period as zero if you want all the users to be loaded without any lime lag. You can put a time lag between each user request by using the formula: Time Lag=Time/No. of users 

You set the loop count to specify how many times do you want each user to hit the web service. If you want to continue loading the web service then you can check the 'Forever' option on the Thread Group element UI.

You can also schedule the load tests by using the 'Scheduler' option provided on the 'Thread Group' UI.

Add a WebService Request

Right click on the 'Thread Group' element and select ' Add --> Sampler --> WebService (SOAP) Request' 

Adding WebService Request

Load the WSDL after putting the wsdl in the 'WSDL URL' text box and select the target web method from the 'Web Methods' drop down. configure the server, IP, port, and path.
Copy the SOAP request XML in the 'Soap/XML-RPC Data' text box you provide the path of the file  in the 'Filename' section. Make sure to check the 'Read SOAP Response' check box to ensure that the soap response is read for asserting the results.

Apply Assertions on the Response

Right click on the 'Thread Group' element and select ' Add --> Assertions --> Response Assertions' 

Applying Assertion on Response

Select the radio button 'Main Sample only' in the Apply to section. Then select the 'Text Response' radio button in the Response Field to Test section. Add the pattern to test in the response of the SOAP request. For example if you expect the text '<status>Completed</status>' in the response than you may want to add an assertion to check if the text: "<status>Completed</status>" is present in the response.

View Results

We can view the results of the tests in multiple format, such as Graph, Table or Tree structure. The results can also be stored in files at a specified location. In our case we will be using 'Graph Results' and 'View Results Tree' elements.

Graph Results element can be added from 'Add-->Listeners-->Graph Results' and View results tree element can be added at 'Add-->Listeners-->View Results Tree'.

Adding Graph Results

Provide location of the results file in the 'Filename' section. You can create a new results file and point its location in the 'Filename' section.

You can now run the test and see the Graph and Results Tree as follows:

Graph Results

The result tree is displayed as follows:

Results Tree

Now you may want to pass the output from one request to the input of the next request.