Hi,
Can you give me a step by step process to upgrade Hadoop version from 2.5.1 to 2.7.3 (Running Hbase 1.2.5) We have a cluster setup of 3 Journalnodes 1 active and 1 Backup namenode 15 datanodes Please let know the process how to *upgrade without downtime* -- *REGARDS* *KRISHNA V* *contact # 7200834601*