Discovery configuration changes in 7.x

Elastic Stack Elasticsearch
#1

Before an upgrade to 7.x, why is it required to set the below value
discovery.zen.ping.unicast.hosts ?

" After the cluster forms successfully for the first time, remove the cluster.initial_master_nodes setting from each nodes' configuration. Do not use this setting when restarting a cluster or adding a new node to an existing cluster."

Does this setting needs to be explicitly removed from elasticsearch.yml file after cluster bootstrapping is completed?

#2

Yes you should remove cluster.initial_master_nodes from your config file once the cluster has formed for the first time.

You should not use discovery.zen.ping.unicast.hosts at all in 7.x, instead use discovery.seed_hosts, and don't remove this from your config file.

1 Like
#3

Thanks for the reply.
I think my first question is not clear. let me rephrase it.
Before an upgrade to 7.x, In the documentation i see its mentioned that we need to set the below value discovery.zen.ping.unicast.hosts
So i infer that we need to set this value in 6.x before i upgrade to 7.x.
Why is this required?

#4

The documentation you quoted does not mention discovery.zen.ping.unicast.hosts.

#5

" The first three settings in this list are only available in versions 7.0 and above. If you are preparing to upgrade from an earlier version, you must set discovery.zen.ping.unicast.hosts or discovery.zen.hosts_provider ."

we need to set this value in 6.x before i upgrade to 7.x.
Why is this required?

#6

Hi David,

What happens if we keep the setting "cluster.initial_master_nodes" even after cluster formation ?

And i think what Srikanth was asking is, does it really necessary to set "discovery.zen.ping.unicast.hosts" to list of master eligible nodes on all the nodes in 6.8 (6.x) cluster before upgrading to 7.x ?

#7

There's a risk that you accidentally bootstrap a second cluster in the future, which would be bad because you can't merge clusters together.

You would normally set discovery.zen.ping.unicast.hosts to the addresses of the master-eligible nodes in 6.8 anyway?