Does the quartz scheduler create a new thread for each of the triggers, or only one thread that takes care of all the threads?
Quartz uses a custom thread pool to perform scheduled tasks. Therefore, threads must be recycled between tasks. How many threads exist in parallel can be configured as described here: http://www.quartz-scheduler.org/documentation/quartz-2.x/configuration/ConfigThreadPool
As you can implement the ThreadPool interface implementations yourself, you can reject and create a "ThreadPool" that does not integrate at all. (The interface for implementation is described here: http://www.docjar.com/docs/api/org/quartz/spi/ThreadPool.html )