Cloudera Docs

Configuring high availability for Cloudera Data Explorer (Hue)

To enable high availabilty for Data Explorer, you must configure at least two Data Explorer servers, each on a different host and a load balancer.For secure connections, enable TLS/SSL and install Kerberos. Configuring Data Explorer for high availability includes configuring Data Explorer, Hive, and Impala.

  • Provide SSH network access to host machines with a Data Explorer Server/Kerberos Ticker Renewer role.
  • Configure each Data Explorer server to point to an external database. Cloudera recommends to use an external database for clusters with multiple Data Explorer servers so that no matter which server is being used, the data is always accessible. In a multi-server environment with a default embedded database (one per server), the data on server "A" can appear lost when working on server "B" if the server "A" becomes unavailable (which has the Data Explorer backend database) and vice versa.
  1. Log in to Cloudera Manager as an Administrator.
  2. Add Hue roles:

    Hue HA requires at least two Hue server roles and one Load Balancer role. If the cluster is authenticating with Keberos, you need one Kerberos Ticker Renewer on each host with a Hue Server.

    1. Go to the Hue service and select Actions > Add Role Instances.
    2. Click Hue Server, assign to one or more hosts, and click OK > Continue.
    3. Click Kerberos Ticket Renewer, assign to each host with a Hue Server, and click OK > Continue.
    4. Click Load Balancer, assign to one or more hosts, and click OK > Continue.
    5. Check each role and select Actions for Selected > Start and click Start.
  3. Enable TLS for the Hue Load Balancer:
    1. Go to Hue > Configuration and search on TLS/SSL.
    2. Check Enable TLS/SSL for Hue for the Hue Server Default Group.
    3. Set other TLS/SSL properties appropriate for your setup.
    Some properties to consider are:
    • Hue Load Balancer Port: Apache Load Balancer listens on this port (default is 8889).
    • Path to TLS/SSL Certificate File: Must be multi-domain with CN = Load Balancer in PEM format.
    • Path to TLS/SSL Private Key File: Must be in PEM format.
  4. Optional: Select the Hue Load Balancer Cookie Refresh option from the Configuration tab to optimize the Hue Load Balancer to distribute users equally across the Hue instances.
  5. Click Save Changes.
  6. Restart the Hue service.