Task org.apache.jackrabbit.oak.commons.concurrent.NotifyingFutureTask@6bb5f83a[Not completed, task = org.apache.jackrabbit.oak.spi.commit.BackgroundObserver$1$1@6f8a6113] rejected from java.util.concurrent.ThreadPoolExecutor@2eb76b28[Shutting down, pool size = 1, active threads = 1, queued tasks = 0, completed tasks = 2]