A DESCRIPTION OF THE REQUEST :
The JavaDoc of class ScheduledThreadPoolExecutor documents the behavior as a fixed-size ThreadPoolExecutor:

-- quote --
While this class inherits from ThreadPoolExecutor, a few of the inherited tuning methods are not useful for it. In particular, because it acts as a fixed-sized pool using corePoolSize threads and an unbounded queue, adjustments to maximumPoolSize have no useful effect.
-- quote --

In fact the ScheduledThreadPoolExecutor calls its parent constructor with Integer.MAX_VALUE as maximumPoolSize.

JUSTIFICATION :
Misleading documentation can lead to wrong error analysis or system performance estimations.