How to check the build queue for an existing job name?

Using Jenkins
1

In my setup, I have a pipeline that triggers a job periodically. What I would like to do is to check to see if an existing job is already in the queue so that I don’t unnecessarily trigger another one that may create a resource-starving condition by filling up the queue. From reading the documentation and from experimentation, I see that the items in the queue going through different states and before being assigned an executor, they don’t have an action, therefore, I don’t see a job name associated with the item. So my question is: Is there a way to check if the queue already contain a job matching a particular job name? Thanks for any leads.

Jenkins setup:

Jenkins: 2.426.3
OS: Linux - 6.5.0-17-generic
Java: 17.0.9 - Private Build (OpenJDK 64-Bit Server VM)
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2

Is the job you trigger parameterized? If not you don’t need to care, Jenkins will not put the job in the queue again.
If it is parameterized Jenkins will not put it in the queue when the parameters are identical. If parameters are different the job will be added to the queue.
Other than that you can also disallow concurrent execution of the job so it will not run in parallel.

And is the job you trigger freestyle or pipeline?

Having many items in the queue is not a problem for Jenkins, this will not lead to any resource shortage.

3

Thank you Markus for replying.
Yes, this is a pipeline job that is parameterized. I use the basic “build job” in my pipeline to trigger the automation every x minutes. The issue that I’m seeing is that at the peak hours of usage when our team is using Jenkins heavily for builds, all the agents are occupied and any jobs requested will be queue up at that point. So these periodic jobs will just get queued up, and because our development build cycles (for the developers) take up quite a bit of time, the queue gets pretty large and eventually Jenkins crashes. I can put a safety valve and check the queue size on the periodic pipeline, but ideally, would like to not to put another duplicate job in the queue if I don’t have to. Perhaps I’m doing something wrong with the call to “build job”.

4

pipeline jobs start immediately normally (unless concurrent execution is disabled and the job is already running) and only when a node step is executed they request an executor. When no executor is available then that particular node step will wait in the queue. So getting that information is a bit trickier

queue = Jenkins.get().queue

queue.items.each{ item ->
	task = item.task 
  	if (task instanceof org.jenkinsci.plugins.workflow.support.steps.ExecutorStepExecution.PlaceholderTask) {
  		println("Job name: " + task.getOwnerExecutable().getParent().getFullName())
	} else {
  		println("Job name: " + task.getFullName())
	}
}

this task can be a job (freestyleproject, but can also be a WorkflowJob (=pipeline job), that is waiting) or can be a ExecutorStepExecution.PlaceholderTask (Pipeline: Nodes and Processes 1331.vc8c2fed35334 API) when it is a node step waiting for an executor.

5

Thank you Markus, this is VERY helpful. Really appreciate the help.