Application not running message

Understanding the Application not running message from TEZ that appears in the YARN application log prevents confusion when inspecting Hive queries.

During startup, HiveServer starts sessions that are available until tez.session.am.dag.submit.timeout.secs expires, and then the Application Masters are killed. HiveServer transparently restarts dead AMs on demand when you run another query. HiveServer tries to clean up sessions from the Tez pool during shutdown. "Application not running" message in a stack trace logging is not an issue. This message is just a trace logged when the session is closed or restarted and the AM has timed out.