However if we Go to Clusters > Kudu > Click Actions I see Run Kudu Rebalancer Tool, would like to know, what is the purpose of this. Will this distribute data for overall Kudu or just Kudu Master or Kudu T-Servers too. Request some advice / assistance on the same.
Kudu masters don't serve or store data, so the rebalance tool will rebalance data across all of the tablet servers where the data are stored. You don't need any downtime to run the Kudu cluster rebalance tool.