Upgrading CDH in a Cloudera Manager Deployment
Cloudera Manager supports managing CDH4 and CDH3. To ensure the highest level of functionality and stability, consider upgrading to the most recent version of CDH4. The process of upgrading CDH to the most recent version is different when those CDH installations are managed by Cloudera Manager. You can also upgrade individual products such as Impala and Solr.
Upgrading CDH in a Cloudera Manager managed deployment is described in Managing Clusters with Cloudera Manager.
As of Cloudera Manager 4.5, you can upgrade to CDH4 from within the Cloudera Manager Admin Console using Parcels. You can also upgrade individual products such as Impala using parcels. See Upgrading Using Parcels for a general description of the upgrade process using parcels.
If you are running HDFS High Availability, you can perform a Rolling Upgrade that lets you avoid cluster downtime by using the NameNode Failover mechanism as part of the upgrade process. See Performing a Rolling Upgrade on your Cluster.
Note that doing a CDH upgrade, especially between CDH3 and CDH4 or from CDH4.0 or 4.1 to CDH4.2 may require some extra manual steps to supplement the parcel upgrade process.
See the following topics for details on upgrading to the latest CDH4 (using parcels or packages):