Processing 50000 lines of test data in Katalon Studio

I made a GitHub project

This project was developed in order to propose a solution to a question raised at the Katalon User Forum:app-name:

This project was developed using Katalon Studio v8.2.0 on Mac, but would work on any version of Katalon Studio since v7.x on Windows/Linux as well.

Problem to solve

In Katalon Studio, I have a Test Case which requires some parameters runtime. And I have a CSV file of which lines contain the values to pass to the Test Case.

Let me assume an extreme case: the number of lines is massive: 50,000. If I run the Test Case for 50,000 times sequentially, who knows how long would it take? How many days and nights?

So, I want to somehow split the data into smaller chunks of N groups, and execute N tests in parallel in order to let the tasks to finish faster. N could be 2, 5, 10, 50, …​

I want the codes in the Katalon Studio project as simple and maintainable as possible.

I would start developing the project using Katalon Studio GUI on a laptop machine.

I would imagine distributing the whole task on multiple instances on Cloud with sufficient Katalon Runtime Engine licenses (50 AWS EC2 instances?) as much as the budget allows. With this hope in mind, I want to design the project’s code to run fine in such distributed environment as well as on a laptop.


I would not use Katalon’s Data-driven Testing feature, because I want to control the data-variable binding myself.

I will build a state-of-the-art combination of Test Cases, Execution Profiles, Global Variables, Test Suites, and Test Suite Collections.


I want to achieve a Input-TestCase-Output sceneario as follows.


The input CSV file contains 50000 lines with some valuable data.


0 A2B500
1 FF2F25
2 7BB7D7
3 F97123
4 C33795
49994 D61E39
49995 CF94A5
49996 8982AE
49997 158689
49998 BF45BD
49999 6E3F43

Test Case

The following is the “actual test case”. I wrote it intensionally simple to make it easy to understand. You can implement whatever tests using WebUI.xxxxx keywords as you like here.

This test case expects 2 variables seq and data are supplied by the caller.

Test Case /TC_worker

// here, you can do whatever you want to do
println "${seq} has data ${data}"


I want to split the data lines into smaller chunks, and apply each to the test case.

When lines of (10…13) is applied, in the console, I want to see this:

start=10, end=13
9 has data 11450A
10 has data 47EE38
11 has data 408253
12 has data 5E31FA

And when lines (49801…49803) is applied, I want to see this:

start=49801, end=49803
49800 has data 2AE9F4
49801 has data 3089C4
49802 has data D21BE2

Description how the demo project is implemented

Controller Test Case

I made a Test Case TC_controller which reads the data.csv file in, determines which lines to process, calles TC_worker while passing parameters from the file into the worker.

import static com.kms.katalon.core.testcase.TestCaseFactory.findTestCase
import com.kms.katalon.core.webui.keyword.WebUiBuiltInKeywords as WebUI
import internal.GlobalVariable as GlobalVariable

int start = GlobalVariable.start
int end = GlobalVariable.end

println "start=${start}, end=${end}"

File data = new File("./data.csv")
data.eachLine { line, lineNumber ->
    if (start <= lineNumber && lineNumber <= end) {
        List<String> items = line.split(" ") as List
        WebUI.callTestCase(findTestCase("TC_worker"), ["seq": items[0], "data": items[1]])

Please note that TC_controller requires runtime parameter start and end . And it reads the value from GlobalVariable.start and GlobalVariable.end .

Can you guess what start and end are? start and end decides which portion of lines in the data.csv file to be processed by this time of Controller execution.

If start=10 and end=13 are given, then the controller will call the the worker 4 times while passing the parameters like this:

seq data
9 11450A
10 47EE38
11 408253
12 5E31FA

Execution profiles

  • How can I specify the value of GlobalVariable.start and GlobalVariable.end ?
    • You want to create Execution Profiles that contain these 2 GlobalVariables where you give the value you want
  • How many Execution profiles do I need to create?
    • If you want to split the data.csv file of 50000 lines into 100 chuncks, you would want to create 100 Execution profiles. Namely start1end499 , start500end999 , start1000end1499 , …​


Test Suite

I made Test Suites/TS , which just calls Test Cases/ . No tricks here.


Test Suite Collection

I made a Test Suite Collection TSC . The TSC invokes TS while specifying the name of Execution profiles to apply.


  • How many combinations of Execution Profiles with the TS can I include in the Test Suite Collection?
    • As many as you want. If you have created 100 Execution Profiles, you can include all of them here, or select just a few.
  • Can I execute the included combinations in parallel?
    • Of course, you can try it and see if it runs faster.

Distributed processing on Cloud servers + KRE

As document tells, Katalon Runtime Engine accepts command line arguments

  • -executionProfile start10end20
  • -g_start=10 , -g_end=20

With KRE, you have a lot more flexibility to control the way how to split the data. You can dynamically generate the command line by any scripting technology you like (bash, python, etc)

If you deploy your test as distributed on AWS, as long as your budget allows, you can run 100 instances in parallel so that your test may finish far faster than a single laptop.

Filter data and Go

50000 lines of data — it is too much to apply to a UI test as one go. I want to dynamically extract some smaller portion of data lines; 10 lines, 50, … 100 at most. How can I do it?

I wrote Test Cases/ .

import static com.kms.katalon.core.testcase.TestCaseFactory.findTestCase

import com.kms.katalon.core.webui.keyword.WebUiBuiltInKeywords as WebUI

import internal.GlobalVariable

String pattern = GlobalVariable.DataStartsWithPattern

println "pattern=${pattern}"

File data = new File("./data.csv")
int count = 0
data.eachLine { line, lineNumber ->
    List<String> items = line.split(" ") as List
    if (items[1].toUpperCase().startsWith(pattern.toUpperCase())) {
        WebUI.callTestCase(findTestCase("TC_worker"), ["seq": items[0], "data": items[1]])
        count += 1

println "count=${count}"

When I set GlobalVariable.DataStartsWithPattern='FF1' and run this test case, I saw in the console

2040 has data FF11DA
4227 has data FF155D
5264 has data FF1563
7344 has data FF15AF
7664 has data FF1908
11135 has data FF1504
28194 has data FF1250
29614 has data FF1A82
42775 has data FF1083
48683 has data FF1AFD

TC_controller_filtering_data extracted 10 lines out of 50000, and called TC_worker just 10 times.

The point is that I do not use Katalon’s Data-driven testing feature. I do data-binding for myself; I can design and implement the rule how to filter the smaller chuck out of the mass.