- 
    Bug 
- 
    Resolution: Fixed
- 
    Critical 
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    Jenkins 1.607-1.609
 Throttle concurrent builds plugin 1.8.4
After upgrading to 1.607 we noticed the throttle plugin doesn't always prevent jobs from running in parallel as expected.
Steps to reproduce:
1. Create a throttle category with global limit 1, per-node limit 1.
2. Create 3 jobs using the category, restricted to a node with two executors, sleep 60 as a build step.
3. Request builds of all 3 jobs.
What should happen:
4. Jobs run in sequence; 1 then 2 then 3.
What actually happens:
5. Job 1 starts building, jobs 2 and 3 wait in queue (OK).
6. After job 1 finishes, both job 2 and 3 start running (not OK).
Plugin version is 1.8.4. Issue does not appear in Jenkins 1.606 with the same version of the plugin. Issue is reproducible on a fresh install.
We were forced to downgrade back to 1.606 as a workaround (which is unfortunately not trivial due to JENKINS-27700).
- is duplicated by
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                    JENKINS-20211 Pairs of throttled node labels no longer seem to work starting from version 1.536 -         
- Resolved
 
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                    JENKINS-28084 One per node / One per total Category still allows multiple concurrent builds (regression) -         
- Resolved
 
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- is related to
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                    JENKINS-28376 jobs get stuck in queue from time to time -         
- Resolved
 
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                    JENKINS-27565 Nodes can be removed as idle before the assigned tasks have started -         
- Closed
 
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                    JENKINS-27650 Page loads slow with hundreds of throttled builds in queue -         
- Open
 
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                    JENKINS-28887 blocking jobs -         
- Resolved
 
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                    JENKINS-27871 Block on upstream projects does not work -         
- Closed
 
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