Nodes not joing cluster

Elastic Stack Elasticsearch
1

Hello !
I can't make my nodes join the cluster. I get an cluster uuid like na...
I don't know if this is because i upgraded to 6.2.2 from 5.X (5.3 or 5.6 i don't remember)

{
  "name" : "md2es",
  "cluster_name" : "md2es",
  "cluster_uuid" : "FMIiKfV1RoGhkd-jBiAe4g",
  "version" : {
    "number" : "6.2.2",
    "build_hash" : "10b1edd",
    "build_date" : "2018-02-16T19:01:30.685723Z",
    "build_snapshot" : false,
    "lucene_version" : "7.2.1",
    "minimum_wire_compatibility_version" : "5.6.0",
    "minimum_index_compatibility_version" : "5.0.0"
  },
  "tagline" : "You Know, for Search"
}

And in the other node i got that

{
  "name" : "md2puteaux",
  "cluster_name" : "md2es",
  "cluster_uuid" : "_na_",
  "version" : {
    "number" : "6.2.2",
    "build_hash" : "10b1edd",
    "build_date" : "2018-02-16T19:01:30.685723Z",
    "build_snapshot" : false,
    "lucene_version" : "7.2.1",
    "minimum_wire_compatibility_version" : "5.6.0",
    "minimum_index_compatibility_version" : "5.0.0"
  },
  "tagline" : "You Know, for Search"
}

Here is my yml :
cluster.name: "md2es"
node.name: "md2puteaux"
path.data: /var/lib/elasticsearch
path.logs: /var/log/elasticsearch
#network.bind_host: 0
network.host: 0.0.0.0
discovery.zen.ping.unicast.hosts: ["ip:9300"]
bootstrap.memory_lock: true

Thanks for help

2

This need to contain the IP of the other node? Is that what you have in your config?

If you have 2 master eligible nodes you should also set minimum_master_nodes to 2.

3

I just masked my ip for confidentiality...

4

Yes, but which IP is that?

5

It's the ip of my other server. And in my other server I put the ip of the first server.

6

Any firewall blocking access to port 9300? Are you able to telnet from one host to port 9300 on the other?

7

Yeah, all ports are open. Everything is fine. I have 2 elastics servers, they work fine in the cluster. I need to disable one and put a new one. But the new server (same config) don't join the cluster...

9

Up ? I'm still trying everything and I don't found a solution... Now sometimes I get the same cluster uuid instead of na..... but shards are not joining... I don't have logs for that.
I tried to increase the number of replicas...

10

Can you telnet to from one node to the other on port 9300? Is there anything in the Elasticsearch logs? Can you add both IP addresses to discovery.zen.ping.unicast.hosts just to make sure it is symmetrical? Do you have any other non-default configuration settings?