SOAP is a messaging protocol specification for exchanging structured information in the implementation of web services. Its purpose is to induce extensibility, neutrality, and independence. It uses XML Information Set for its message format and relies on application layer protocols.

SOAP is used in a variety of messaging systems. It is delivered via a variety of transport protocols and the initial focus of SOAP is remote procedure calls transported via HTTP.

Many applications run on web services in today’s world. Some of them runs on SOAP services, some of them on RESTFUL services which support the JSON messaging format. That’s why performing a load test on these messaging protocols is crucial.

We’ll explain how to test these kinds of web services via, open source, Apache JMeter testing tool. We’ll use a simple calculator web service as an example. You can do simple Add, Subtract, Multiply and Divide operations.

Create Your First Service Call

Create a Thread Group and Add an HTTP sampler as a child element to it.

In this HTTP Sampler, you have to fill some fields;

1. The protocol must be filled out to specify if it’s an HTTPS or HTTP.
2. The server name must be filled out with the IP address or the domain name.
3. A method is the most crucial one. You have many options. You need to know which method you are able to run on that web services. The method can be POST, GET, PUT, DELETE, etc…
4. The path must be filled out to specify the endpoint of the web services. 

Note: It would be the best practice to separate the server name and path from each other. In case there’s any change in the test environment, server name may change but the method is likely to stay as the same.

Implement a GET Request

Send a GET request to get operation supported by your SOAP web services. Fill the path as calculator.asmx?WSDL (web services description language). This is the first web service call.

Add a View Results Tree Listener into your test to analyze the results.

Run your test and you will receive a response from the web service. If you take a look at the response, you’ll be able to see the operations name and parameters to send to these services. In this example, Add is an operation and it takes two integer parameters with intA and intB as variables name.

Implement a POST Request

Let’s implement a POST request to one of the supported operations.

Change the Path to /calculator.asmx and send below payload with it as seen in the picture:

<?xml version=”1.0″ encoding=”utf-8″?>
<soap:Envelope
	xmlns:xsi=”http://www.w3.org/2001/XMLSchema-instance”
	xmlns:xsd=”http://www.w3.org/2001/XMLSchema”
	xmlns:soap=”http://schemas.xmlsoap.org/soap/envelope/”>
	<soap:Body>
		<Add
			xmlns=”http://tempuri.org/”>
			<intA>20</intA>
			<intB>5</intB>
		</Add>
	</soap:Body>
</soap:Envelope>

Implement the other services by following the first example. Now you’re ready to go.

Note: There might be some cases where you need to specify headers to your web services. Header refers to supplemental data placed at the beginning of a block of data being stored or transmitted like content type, HTTP version, user agent, etc. In case you have such a requirement, just add an HTTP Header Manager to your sampler as follows. Content will change according to your web services.

Run your test once again and see the results flow like a charm.

Happy load testing!