title: Upgrading from 5.2.2 to 6.4.2 (yum install VS yum update)
body: <p>Need to perform upgrade on 3-nodes ES clusters and writing test script before putting it to playbook. Anyone updated ES with yum update instead of install (OS AWS RHEL 7.2) ???</p>
  
  <p>Here's the install script, I will be grateful for your comments:</p>
  
  <pre>
  #Installing from the RPM repository
  #Create a file called elasticsearch.repo in the /etc/yum.repos.d/ directory for RedHat based distributions, 
  
  #DO UPGRADE
  #In the terms of ordering, update first the master nodes, then data nodes, then load-balancing/client nodes.
  
  #Disable Shard reallocation
  curl -XPUT localhost:9200/_cluster/settings -d '{ "transient" : { "cluster.routing.allocation.enable" : "none" } }'
  
  #Shutdown the instance:
  curl -XPOST 'http://localhost:9200/_cluster/nodes/_local/_shutdown'
  
  sudo systemctl stop elasticsearch
  sudo yum update elasticsearch
  sudo systemctl start elasticsearch
  
  #Enable shard re-allocation:
  curl -XPUT localhost:9200/_cluster/settings -d '{ "transient" : { "cluster.routing.allocation.enable" : "all" } }'
  
  #Watch cluster go from yellow state to green with:
  curl -X GET http://localhost:9200/_cat/health?v // monitors the overal cluster state
  curl -X GET http://localhost:9200/_cat/nodes?v // verify that the new node joined the cluster
  curl -X GET http://localhost:9200/_cat/shards?v // see shards being started, initialized and relocated
  
  #Repeat for the next node.
  </pre>
  
  <p>Kind Regards,
  P.</p>