For production environments, you must configure high availability for Key Trustee Server and Key Trustee KMS.

For high availability, you must provision two dedicated Key Trustee Server hosts and at least two dedicated Key Trustee KMS hosts, for a minimum of four separate hosts. Do not run multiple Key Trustee Server or Key Trustee KMS services on the same physical host, and do not run these services on hosts with other cluster services. Doing so causes resource contention with other important cluster services and defeats the purpose of high availability. See Data at Rest Encryption Reference Architecture for more information.

The Key Trustee KMS workload is CPU intensive. Cloudera recommends using machines with capabilities equivalent to your NameNode hosts, with Intel CPUs that support AES-NI for optimum performance.

Make sure that each host is secured and audited. Only authorized key administrators should have access to them. Red Hat provides security guides for RHEL:

• RHEL 6 Security Guide
• RHEL 7 Security Guide

For hardware sizing information, see Data at Rest Encryption Requirements for recommendations for each Cloudera Navigator encryption component.

For Cloudera Manager deployments, deploy Key Trustee Server in its own dedicated cluster, which can be used by other clusters. Deploy Key Trustee KMS in each cluster that uses Key Trustee Server. See Data at Rest Encryption Reference Architecture for more information.