How to fix elasticsearch node version number in a cluster (having 2 different version nodes)

Question

In my elasticsearch cluster i have 2 nodes. 1 is of version 1.7.3 and other of version 1.7.5.(my elasticsearch v1.7.3 got corrupted so reinstalled 1.7.5) how can i upgrade the node from 1.7.3 to 1.7.5

refered: https://www.elastic.co/guide/en/elasticsearch/reference/1.7/setup-upgrade.html#rolling-upgrades . But could not get the procedure for upgradation of nodes version.

kindly help me through this.

my cluster is green.

and nodes are as follows:

{ "cluster_name" : "graylog2", "nodes" : {

"mC4Osz5IS0OLy2E8QbqZLQ" : {
  "name" : "Decay II",
  "transport_address" : "inet[/127.0.0.1:9300]",
  "host" : "localhost",
  "ip" : "127.0.0.1",
  "version" : "1.7.5",
  "build" : "00f95f4",
  "http_address" : "inet[/127.0.0.1:9200]",
  "process" : {
    "refresh_interval_in_millis" : 1000,
    "id" : 957,
    "max_file_descriptors" : 65535,
    "mlockall" : false
  }
},

"qCDvg4XCREmj_iGmbt4v4w" : {
  "name" : "graylog2-server",
  "transport_address" : "inet[/127.0.0.1:9350]",
  "host" : "localhost",
  "ip" : "127.0.0.1",
  "version" : "1.7.3",
  "build" : "05d4530",
  "attributes" : {
    "client" : "true",
    "data" : "false",
    "master" : "false"
  },
  "process" : {
    "refresh_interval_in_millis" : 1000,
    "id" : 8937,
    "max_file_descriptors" : 64000,
    "mlockall" : false
  }
}

i suspect the difference in the version is the cause of the graylog refusing connection with the elasticsearch cluster

please help

Answer 1

Hmmmm I can't think of one of two ways to do this

1. Add 3rd node on 1.75, wait for it to go green. Shutdown 2, upgrade and re-introduce to cluster.

2. Shutdown cluster. Upgrade node to 1.75. Start node mC4Osz5IS0OLy2E8QbqZLQ first and then the other one.