Use case: We use Jenkins to as a central location to run cron jobs across servers.

issue; if we need to do maintenance on jenkins we do not want any cron jobs to run from jenkins at this time so we disable the master node and set the number of executors to 0.
upon reboot jenkins will begins executing the next 15 jobs in the queue ( number of previous executors) however upon these jobs finishing jenkins will remove the executor returning the number of executors back down to 0.

Why is jenkins starting up with 15 executors when it is manually set to 0?