Task org.apache.jackrabbit.oak.commons.concurrent.NotifyingFutureTask@6513a3c8[Not completed, task = org.apache.jackrabbit.oak.spi.commit.BackgroundObserver$1$1@2ea460cc] rejected from java.util.concurrent.ThreadPoolExecutor@9cc11a8[Shutting down, pool size = 1, active threads = 1, queued tasks = 0, completed tasks = 6]