Task org.apache.jackrabbit.oak.commons.concurrent.NotifyingFutureTask@5443f4d6[Not completed, task = org.apache.jackrabbit.oak.spi.commit.BackgroundObserver$1$1@507c6a01] rejected from java.util.concurrent.ThreadPoolExecutor@60866ff5[Shutting down, pool size = 1, active threads = 1, queued tasks = 0, completed tasks = 5]