Cloudera Docs

Enabling Catalog and StateStore High Availability (HA)

You can use Cloudera Manager to enable Catalog and StateStore HA for a cluster. When enabled, the preemptive behavior allows one of the Catalogd and StateStore pair to become active, and the other paired Catalogd and StateStore to become a standby.

  • You must configure at least two Impala Catalogd and two StateStore instances on two different nodes.
  • To avoid incompatible Impala versions, High Availability should be enabled before or after rolling upgrades.
  • Ensure that all nodes running Impala service are using the same CDP Parcel version.
  1. Log in to Cloudera Manager as an Administrator
  2. In Cloudera Manager, select Impala > Actions > Enable High Availability.
    Enabling Impala High Availability
  3. On the Assign Roles page click Select a host for the Catalog to act as a standby Impala Catalog server.
  4. On the Hosts Selected page, the existing Catalog instance is selected by default. Select a backup Catalog host.
    An ICS icon appears in the Added Roles column for the Catalog server.
  5. On the Assign Roles page click Select a host for the StateStore to act as a standby Impala StateStore server.
  6. On the Hosts Selected page, the existing StateStore instance is selected by default. Select a backup StateStore host.
    An ISS icon appears in the Added Roles column for the StateStore server.
  7. Click OK.
  8. Click Continue on the Review Changes page.
    Review the summary of actions when you add a new host. When a new host is selected, Impala and its dependent services are restarted.
You notice two Impala Catalog servers and two Impala StateStore servers under Impala > Instances page.