I have a worker my_tree worker as shown in my backgroundrb.yml file below. I played around with the trigger_args setting which I had it calling update_main_tree() every 1 minute. This opens a tree structure in my db that I set and rebuilds it. After it seemed to be working ok, I then set the tree to be updated to be a larger tree and set the trigger_args to happen at 8:00 pm, and then went home. I do not have reload_on_schedule set. When I came in the next day, my machine was nearly hung as at 8:00 pm according to my log file, 8 different workers got launched on update_main_tree()
:schedules: :session_mgr_worker: :expire_sessions: :trigger_args: 0 0 */6 * * * * :my_tree_worker: :update_main_tree: :trigger_args: 0 0 20 * * * * # :trigger_args: 0 */1 * * * * *