Jenkins parameterized job that only queues one build

Question

Imagine a Jenkins job A which takes 1 minute to run, and job B which takes 5 minutes.

If we configure job A to trigger job B, while job B is running job A may run 5 times before B completes. However, Jenkins doesn't add 5 builds to job B's queue, which is great because otherwise speedy job A would be creating an ever-growing backlog of builds for poor slow job B.

However, now we want to have job A trigger B as a parameterized job, using the parameterized trigger plugin. Parameterized jobs do queue up a backlog, which means job A is happily creating a huge pile of builds for job B, which can't possibly keep up.

It does make sense to add a new parameterized build to the queue each time it's triggered, since the parameters may be different. Jenkins should not always assume that a new parameterized build renders previously queued ones unnecessary.

However, in our case we actually would like this. Job A builds and packages our application, then Job B deploys it to a production-like environment and runs a heavier set of integration tests. We also have a build C which deploys to another environment and does even more testing, so this is an escalating pattern for us.

We would like the queue for our parameterized job B to only keep the last build added to it; each new build would replace any job currently in the queue.

Is there any nice way to achieve this?

Answer 1

Add a "System Groovy Script" pre-build step to job B that checks for (newer) queued jobs of the same name, and bails out if found:

def name = build.properties.environment.JOB_NAME
def queue = jenkins.model.Jenkins.getInstance().getQueue().getItems()
if (queue.any{ it.task.getName() == name }) {
  println "Newer " + name + " job(s) in queue, aborting"
  build.doStop()
} else {
  println "No newer " + name + " job(s) in queue, proceeding"
}