killing/stopping Jenkins job with a very long list - jenkins

Question

I'm new to Jenkins so I hope my terms are correct:
I have a Jenkins job that triggers another job. This second job tests a very long list of items (maybe 2000) it gets from the trigger.
Because it's such a long list, I pass it to the second job in groups of 20.
Unfortunately, this list turned out to take an extremely long time, and I can't stop it.
No matter what I tried, stop/kill only stop the current group of 20, and proceeds to the group.
Waiting for it to finish, or doing this manually for each group is not an option.
I guess the entire list was already passed to the second job, and it's loading the next group whenever the current one ends.
What I tried:
Clicking the "stop" button next to the build on the trigger and the second job
Using purge build queue add on
Using the following script in script console:
def jobname = "Trigger Job"
def buildnum = 123
def job = Jenkins.instance.getItemByFullName(jobname)
for (build in job.builds) {
if (buildnum == build.getNumber().toInteger()){
if (build.isBuilding()){
build.doStop();
build.doKill();
}
}
}
Using the following script in script console:
String job = 'Job name';
List<Integer> build_list = [];
def result = jenkins.model.Jenkins.instance.getItem(job).getBuilds().findAll{
it.isBuilding() == true && (!build_list || build_list.contains(it.id.toInteger()))}.each{it.doStop()}.collect{it.id};
println new groovy.json.JsonBuilder(result).toPrettyString(); ```
This is my groovy part of the code that splits it into groups of 20. Maybe I should put the parallel part outside the sub list loop?
Is there a better way to divide into sub lists for future use?
stages {
stage('Execute tests') {
steps {
script {
// Limit number of items to run
def shortList = IDs.take(IDs.size()) // For testing purpose, can be removed if not needed
println(Arrays.toString(shortList))
// devide the list of items into small, equal,sub-lists
def colList = shortList.toList().collate(20)
for (subList in colList) {
testStepsForParallel = subList.collectEntries {
["Testing on ${it}": {
catchError(buildResult: 'FAILURE', stageResult: 'FAILURE') {
stage(it) {
def buildWrapper = build job: "Job name",
parameters: [
string(name: 'param1', value: it.trim()),
string(name: 'param2', value: "")
],
propagate: false
remoteBuildResult = buildWrapper.result
println("Remote build results: ${remoteBuildResult}")
if (remoteBuildResult == "FAILURE") {
currentBuild.result = "FAILURE"
}
catchError(stageResult: 'UNSTABLE') {
copyArtifacts projectName: "Job name", selector: specific("${buildWrapper.number}")
}
}
}
}]
}
parallel testStepsForParallel
}
}
}
}
}
Thanks for your help!
Don't know what else to do to stop this run.