Please check which CDH version the cluster has. Cloudera ODBC Driver version 2.5.x in general is compatible with CDH 5.x, for CDH 6.x please use the latest 2.6.x version, please check our website / Downloads section. To further triage this: - Try to connect directly to a specific Impala coordinator host instead of the load-balancer - if load-balancer is used - Enable the driver side logging (check the driver's "Installation guide" how to enable it) which can give further clues.  - Cross check that the Impala service is indeed SSL enabled, use different "openssl" commands to verify the certificate presented by the service, including the truststore used on the client side   Hope this helps,  Miklos Szurap, Customer Operations Engineer, Cloudera ... View more