Task org.apache.jackrabbit.oak.commons.concurrent.NotifyingFutureTask@56f6ce10[Not completed, task = org.apache.jackrabbit.oak.spi.commit.BackgroundObserver$1$1@7ae9c6fb] rejected from java.util.concurrent.ThreadPoolExecutor@4b59bac2[Shutting down, pool size = 1, active threads = 1, queued tasks = 0, completed tasks = 8]