I have a cluster that was working fine for weeks and am mainly using Impala on Kudu tables. Sentry is running on the cluster. Since recently I get an error for the 'DROP TABLE ' command:
`ImpalaRuntimeException: Error making 'dropTable' RPC to Hive Metastore: CAUSED BY: MetaException: Failed to connect to Sentry service null`.
I believe that the data indeed was deleted, since a SELECT query on the table will complain he can not find the file in hdfs.
When I run the 'invalidate metadata' command before dropping the table, the error goes away, but not always.If I would try to drop the same table again(I believe at this point the data is already removed), after the 2nd attempt I would get following error:
`ImpalaRuntimeException: Table xxx no longer exists in the Hive MetaStore. Run 'invalidate metadata xxx' to update the Impala catalog.`
Note: this does not happen with tables I created in Hive and that I now try to query in Impala-they are created all in Impala.I did not have the error before, and feel like it started since I have run an 'invalidate metadata statement' for some other reason for the first time recently .
Thanks for input
Note that this was resolved by restarting the impala and sentry service in the cloudera manager.