Presently, once a test has begun, then the rampup logic will continue to add threads at the defined rate until the rampup period has expired. This is a RFE for: 1. An option to pause the rampup such that any threads that have already been started continue to execute but no new threads are added 2. A related option to resume the rampup and continue to add threads at the previous rate.
See this project and related requirement: - https://github.com/delirius325/jmeter-live-changes-config/issues/4
This issue has been migrated to GitHub: https://github.com/apache/jmeter/issues/2835