Hello  @du_datafactory  , Thank you for reaching out to the Cloudera Community. May I ask if you're experiencing the same issue that @learndeb  reported, or are you seeing a different error? Based on the logs shared in the original post, the issue appears to be related to the communication between Impala/HiveServer2 and Ranger, rather than an issue with Impala query processing itself. The "Received NULL response" while downloading Ranger policies is typically a secondary symptom that can occur if Impala or HiveServer2 is unable to successfully authenticate (for example, due to TLS or Kerberos authentication issues) before retrieving authorization policies from Ranger Admin. If you could share the exact error you're encountering, along with any initial troubleshooting you've performed (for example, relevant Impala, HiveServer2, or Ranger logs), we'd be happy to help you investigate the issue further. ... View more