Task org.apache.jackrabbit.oak.commons.concurrent.NotifyingFutureTask@2bab50db[Not completed, task = org.apache.jackrabbit.oak.spi.commit.BackgroundObserver$1$1@2f94c1f1] rejected from java.util.concurrent.ThreadPoolExecutor@6ea9cbca[Shutting down, pool size = 1, active threads = 1, queued tasks = 0, completed tasks = 4]