Performing Maintenance on a Cluster Host

You can perform minor maintenance on cluster hosts by using Cloudera Manager to manage the host decommission and recommission process.

In this process, you can specify whether to suppress alerts from the decommissioned host and, for hosts running the DataNode role, you can specify whether or not to replicate under-replicated data blocks to other DataNodes to maintain the cluster's replication factor. This feature is useful when performing minor maintenance on cluster hosts, such as adding memory or changing network cards or cables where the maintenance window is expected to be short and the extra cluster resources consumed by replicating missing blocks is undesirable.

You can also place hosts into Maintenance Mode, which suppresses unneeded alerts during a maintenance window but does not decommission the hosts.

To perform host maintenance on cluster hosts:
  1. Decommission the hosts.
  2. Perform the necessary maintenance on the hosts.
  3. Recommission the hosts.