Apache JMeter Tutorial => Parameterization using external files

Example

One of the common ways to parametrize your performance scripts is to use a CSV file. The best example of CSV input files usage is a login process. If you want to test your application across different users, you need to provide a list of user credentials.

Let’s assume that we have a login request that works for one specific user:

We can easily parametrize that request by using an external CSV file and running the script across different users. To add CSV parametrization config:

Right click on login request -> Add -> Config Element -> CSV Data Set Config

A short explanation of ‘CSV Data Set Config’ parameters:

Name - element name as it will be used in the JMeter tree
Filename - name of the input file. Relative file names are resolved based on the path of the active test plan. Absolute filenames are also supported
File Encoding - encoding of input file, if it’s not the platform default
Variable Names - list of separated variable names that will be used as a container for parsed values. If empty, the first line of the file will be interpreted as the list of variable names
Delimiter - delimiter that will be used to split the parsed values from the input file
Allow quoted data? - true in case you want to ignore double quotes and allow such elements to contain a delimiter.
Recycle on EOF? - true in case the file test plan should iterate over the file more than once. It will instruct JMeter to move the cursor at the beginning of the file
Stop thread on EOF? - false in case of loop iteration over the CDC file and true if you want to stop the thread after reading the whole file
Sharing mode:
- All threads - the file is shared between all virtual users (the default)
- Current thread group - the file will be opened once for each thread group
- Current thread - each file will be opened separately for each of threads
- Identifier - all threads sharing the same identifier also share the same file

Let’s create a csv file containing different users with names and passwords:

We can now use this file with the CSV Data Set config. In our case, it’s enough to add the “Filename” and “Variables Names” config values:

The last step we have to take is to parametrize the login request with CSV variables. This can be done by substituting the initial values with appropriate variables from the “Variable Names” configuration field of the CSV Data Set Config, like this: If we run our test script now, JMeter will substitute these variables with values from the ‘TestUsers.csv’ file. Each JMeter virtual user will receive credentials from the following csv file line.