Elasticsearch cluster UUID is not available after version upgrade

Hi There,

we use only Elasticsearch and upgraded it from 6.7.0 to 7.16.2 . we run the Elasticsearch in kubernetes and after version upgrade, cluster UUID is not available. We have one master node , 3 data nodes, 1 coordinating node and cluster UUID is not available across all the nodes. Can i please know how to generate the cluster UUID.

"name" : "es-master",
  "cluster_name" : "apache",
  "cluster_uuid" : "_na_",
  "version" : {
    "number" : "7.16.2",
    "build_flavor" : "default",
    "build_type" : "tar",

I found below log messages on master node, co-ordinating node, data logs but all these pods are deployed in same namespace and not sure what is causing the connection refused error . Is this the reason the cluster UUID is not available ?

es-master logs:

[2022-01-14T20:04:21,048][WARN ][o.e.d.PeerFinder ] [es-master] address [192.168.168.222:9300], node [null], requesting [false] connection failed: [gbi-es-coordinating][100.102.196.190:9300] non-master-eligible node found

es-coordinating logs:

[2022-01-14T20:05:54,078][WARN ][o.e.d.PeerFinder ] [gbi-es-coordinating] address [192.168.198.238:9300], node [null], requesting [false] connection failed: [es-data][100.105.252.18:9300] non-master-eligible node found

es-data logs:

[2022-01-14T20:06:56,510][WARN ][o.e.d.PeerFinder         ] [es-data] address [192.168.168.222:9300], node [null], requesting [false] connection failed: [gbi-es-coordinating][100.102.196.190:9300] non-master-eligible node found
bash-4.2#

Thanks

The logs you shared aren't helpful, but there will be other logs that do help. I suggest you share a more complete set of logs.

[2022-01-14T23:17:24,743][WARN ][o.e.d.PeerFinder         ] [es-master] address [192.168.62.148:9300], node [null], requesting [false] connection failed: [es-master][100.106.199.189:9300] local node found
[2022-01-14T23:17:24,745][WARN ][o.e.d.PeerFinder         ] [es-master] address [192.168.147.53:9300], node [null], requesting [false] connection failed: [gbi-es-coordinating][100.106.26.195:9300] non-master-eligible node found
[2022-01-14T23:17:24,748][WARN ][o.e.d.PeerFinder         ] [es-master] address [192.168.240.43:9300], node [null], requesting [false] connection failed: [es-data][100.102.196.179:9300] non-master-eligible node found
[2022-01-14T23:17:25,745][WARN ][o.e.d.PeerFinder         ] [es-master] address [192.168.62.148:9300], node [null], requesting [false] connection failed: [es-master][100.106.199.189:9300] local node found
[2022-01-14T23:17:25,745][WARN ][o.e.d.PeerFinder         ] [es-master] address [192.168.147.53:9300], node [null], requesting [false] connection failed: [gbi-es-coordinating][100.106.26.195:9300] non-master-eligible node found
[2022-01-14T23:17:25,749][WARN ][o.e.d.PeerFinder         ] [es-master] address [192.168.240.43:9300], node [null], requesting [false] connection failed: [es-data][100.102.43.114:9300] non-master-eligible node found
[2022-01-14T23:17:26,744][WARN ][o.e.d.PeerFinder         ] [es-master] address [192.168.62.148:9300], node [null], requesting [false] connection failed: [es-master][100.106.199.189:9300] local node found
[2022-01-14T23:17:26,746][WARN ][o.e.d.PeerFinder         ] [es-master] address [192.168.147.53:9300], node [null], requesting [false] connection failed: [gbi-es-coordinating][100.106.26.195:9300] non-master-eligible node found
[2022-01-14T23:17:26,747][WARN ][o.e.d.PeerFinder         ] [es-master] address [192.168.240.43:9300], node [null], requesting [false] connection failed: [es-data][100.102.80.23:9300] non-master-eligible node found

But master node is running.

That's still only ~2 seconds of logs and no more information than before. Elasticsearch does log other, more useful, information by default, but you're not sharing enough info for us to help.