Parameterized Load Test
Creating a load test by using parameters and extracting response values
In our first simple test we have simulated users loading the homepage of our blog, our second test is going to simulate several users publishing new entries to the blog.
First create a new empty test. Only logged in users can post to our blog, so let's start by executing a login request and store the authentication token returned by it into a parameter for later use.
Give your new test a short description
Login & Create a blog post
Update the request description to
Blog Login
Set the Request #1 method to
POST
and its URL to -https://loadmill-test-blog.herokuapp.com/ghost/api/v0.1/authentication/token/
Click the "ADVANCED" button to expand the advanced section of the request.
Set the Content-Type to
application/x-www-form-urlencoded
(last in the list).And paste this as the request body -
grant_type=password&username=a@b.com&password=Test1234&client_id=ghost-admin&client_secret=b91601629baf
Expand the “Extractions - Set Parameters” card and set a value to a parameter named
access_token
using aJSONPath
extractor querying foraccess_token
. This will create a value extractor that will execute a JSONPath query against the JSON response of the request and extract the authentication token into a parameter namedaccess_token
.Verify that a value was set to the parameter
access_token
by theJSONPath
extractor by expanding the ‘Verify Response’ card of the request and creating an assertion. Add an assertion that states that theaccess_token
parameterIs True
(Use the "Exists" assertion type).
Click DRY RUN and execute a trial run to make sure it is working.
Now that we have the authentication token stored in
access_token
we can use it to publish on our blogCreate a new request by clicking the "+ ADD REQUEST" button below the first request.
Set its description to
Publish Blog Post
Set it as a
POST
request tohttps://loadmill-test-blog.herokuapp.com/ghost/api/v0.1/posts/
Click on the "ADVANCED" button and set the Content-Type to
application/json
and the body to this JSON-
This JSON body defines the blog post that we are going to publish. Notice that we have used one of Loadmill's functions to make it a little more interesting -
${__random_chars}
. The__random_chars
parameter will change to 10 random characters during test/trial execution.Now, let's use the
access_token
parameter value we extracted from the login response to authenticate this request. Expand the header card of publish request and add a header with the nameAuthorization
and the valueBearer ${access_token}
Run a trial of the whole scenario and go to
https://loadmill-test-blog.herokuapp.com/
to see that our blog posts are getting published.
Now that we know that our full scenario is working we can run it as a load test. Click the "RUN TEST" button at the bottom of the test and run the test 🎉
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