Cloudera Manager is an Infrastructure management and monitoring tool provided by cloudera. This has now became a very excellent tool to manage bigdata infrastructure. The pain of administrators has been reduced by 80% with this cloudera manager. Almost everything required for an administrator is integrated into this great software and is very user friendly. Cloudera Manager became this muhc powerful recently. So lot of existing clusters are still running without using cloudera manager. If you want to manage an existing cluster using cloudera manager, the following steps may help you. For this you have to completely uninstall the existing hadoop set up. No data loss will happen because we are not touching any data. The configurations also will remain the same. These are just pointers.
1) Stop all the services
2) Back up hive metastore, Namenode metadata and all the other required metastores (Eg hue, oozie)
3) Back up all the configurations
4) Note down the existing storage directories
5) Uninstall all the hadoop services (Never touch the data)
6) Install Cloudera Manager Server and Agent
7) Install all the services (It should be same version as that of previous to make installation smoother)
8) Add the configurations (Use the same configurations as that of previous. There is an option to add xml configs in CM)
9) Point the storage directories in the cloudera manager configurations.
10) Point the new installation to the existing metastore (hive, oozie, hue etc)
11) Start all the services (Don’t format the namenode)
12) Test the cluster