Upgrading Jenkins LTS from 2.77 to 2.89 will change Quiet Period effective value from seconds into milliseconds.

ex. 30 sec have to be configured now as 30000.

Use Case:

Set job Quiet Period value from UI. Trigger new build using REST API without delay parameter. 

Reproduce steps:

Step 1. Try Quiet period value 30:

1. Install LTS 2.89.2
2. Create new Freestyle project (ex. trigger_test-quiet_period)
3. Add Quiet Period value to 30 (like in picture). (Quiet period can be found under Advanced.. button in general section)
4. Save the job
5. Build the job by using REST API or for the testing purpose just build directly from browser address bar
   1. http://<jenkins_address>/job/trigger_test-quiet_period/build 
      1. Link can be found by hovering mouse cursor over 
   2. Click proceed
6. Go back to job page http://<jenkins_address>/view/test/job/trigger_test-quiet_period/

Result: Quiet periods is 30ms. Build basically starts immediately.

Excepted result: Quiet period is 30s
 

Step 2. Try Quiet period value 30000:

1. Use same job as in step 1
2. Change Quiet Period value to 30000. (Quiet period can be found under Advanced.. button in general section)
3. Save the job
4. Build the job by using REST API or for the testing purpose just build directly from browser address bar
   1. http://<jenkins_address>/job/trigger_test-quiet_period/build
      1. Link can be found by hovering mouse cursor over 
   2. Click proceed
5. Go back to job page http://<jenkins_address>/view/test/job/trigger_test-quiet_period/

Result: Quiet periods is 30s

Excepted result: Quiet period is over 8h