We are using CM/ CDH 5.3 and planning to enable high availability (HA) (as an alternative method of having a secondary name node) to protect ourselves from name node any possible failure. We need to know after we buy the extra machine (identical to our name node), what steps we need to follow (either by running commands in our CentOS (6.6) name node machine or in Cloudera Manager) before we start following the steps (at CM described here http://www.cloudera.com/content/cloudera/en/documentation/core/latest/topics/cdh_hag_hdfs_ha_enablin... i.e. adding the new node (machine) to the cluster, etc.
Thanks in advance and please let me know if you have any question. Any help much appreciated.
You would need to add the machine to the cluster (so it would have a working agent and parcels) and basically enable HA using CM (HDFS service -> enable HA). If the node is healthy and all the pre-requisites are met, HA should be enabled very easily. It would require a full cluster restart though, so try performing this outside of business hours