# Simple example of new configuration of three node cluster, since v7.x update uses new settings **URL:** \ **Category:** Elasticsearch\ **Created:** [October 16, 2019, 7:55pm UTC](https://discuss.elastic.co/t/simple-example-of-new-configuration-of-three-node-cluster-since-v7-x-update-uses-new-settings/203922 "2019-10-16T19:55:15Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![AnitaL](https://avatars.discourse-cdn.com/v4/letter/a/73ab20/32.png) [@AnitaL](https://discuss.elastic.co/u/AnitaL)\ **Post date:** [October 16, 2019, 7:55pm UTC](https://discuss.elastic.co/t/simple-example-of-new-configuration-of-three-node-cluster-since-v7-x-update-uses-new-settings/203922/1 "2019-10-16T19:55:15Z")
Hi, I took the Elasticsearch Engineer 1 training this summer (ES 6.x), then completed the Engineer 2 training (ES 7.x) Since I learned this the config settings no longer use : ```auto discovery.zen.ping.unicast.hosts: ["server1", "server2", "server3"] discovery.zen.minimum_master_nodes: 2 ``` and instead use ```auto discovery.seed_hosts: ["server1", "server2", "server3"] cluster.initial_master_nodes: ["server1"] ``` Possible to get a simple example of how servers could join a 3 node cluster in ES 7.x ? Is the following correct? First time a "server1" joins a 3 node cluster (server1-3), add this to elasticsearch.yml ```auto discovery.seed_hosts: ["server1", "server2", "server3"] cluster.initial_master_nodes: ["server1"] ``` Then stop server1, delete this line, then restart ```auto cluster.initial_master_nodes: ["server1"] ``` Repeat for server2 and server 3, ie first time server2 joins: ```auto discovery.seed_hosts: ["server1", "server2", "server3"] cluster.initial_master_nodes: ["server2"] ``` I have been referring to [https://www.elastic.co/guide/en/elasticsearch/reference/7.2/discovery-settings.html](https://www.elastic.co/guide/en/elasticsearch/reference/7.2/discovery-settings.html) however would be grateful for a simple example. ---
**Author:** ![DavidTurner](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/davidturner/32/22453_2.png) [@DavidTurner](https://discuss.elastic.co/u/DavidTurner)\ **Post date:** [October 16, 2019, 8:06pm UTC](https://discuss.elastic.co/t/simple-example-of-new-configuration-of-three-node-cluster-since-v7-x-update-uses-new-settings/203922/2 "2019-10-16T20:06:57Z")
Quoting [the docs on `cluster.initial_master_nodes`](https://www.elastic.co/guide/en/elasticsearch/reference/current/discovery-settings.html#initial_master_nodes): > You should not use this setting when restarting a cluster or adding a new node to an existing cluster. Just set `discovery.seed_hosts` and do not mention `cluster.initial_master_nodes`. ---
**Author:** ![AnitaL](https://avatars.discourse-cdn.com/v4/letter/a/73ab20/32.png) [@AnitaL](https://discuss.elastic.co/u/AnitaL)\ **Post date:** [October 16, 2019, 9:09pm UTC](https://discuss.elastic.co/t/simple-example-of-new-configuration-of-three-node-cluster-since-v7-x-update-uses-new-settings/203922/3 "2019-10-16T21:09:21Z")
Thanks David! Indeed you are right about the docs. I don't understand why in I have seen eg: ```auto cluster.initial_master_nodes: ["node1"] ``` when configuring a three node cluster (it is in the ES7 webinar for exam prep) and I also have seen it in the labs when using a single node cluster for the first time, or at least that is what I understood. ---
**Author:** ![DavidTurner](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/davidturner/32/22453_2.png) [@DavidTurner](https://discuss.elastic.co/u/DavidTurner)\ **Post date:** [October 16, 2019, 9:11pm UTC](https://discuss.elastic.co/t/simple-example-of-new-configuration-of-three-node-cluster-since-v7-x-update-uses-new-settings/203922/4 "2019-10-16T21:11:43Z")
> [@AnitaL](#): > > when using a single node cluster for the first time Right, forming a cluster for the first time is quite different from joining a node to an existing cluster, and is exactly the situation in which you must set `cluster.initial_master_nodes`. But you must set it to the same value on every node on which it is set. From [these docs](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-discovery-bootstrap-cluster.html#modules-discovery-bootstrap-cluster): > **WARNING** : You must set `cluster.initial_master_nodes` to the same list of nodes on each node on which it is set in order to be sure that only a single cluster forms during bootstrapping and therefore to avoid the risk of data loss. ---
**Author:** ![AnitaL](https://avatars.discourse-cdn.com/v4/letter/a/73ab20/32.png) [@AnitaL](https://discuss.elastic.co/u/AnitaL)\ **Post date:** [October 16, 2019, 9:22pm UTC](https://discuss.elastic.co/t/simple-example-of-new-configuration-of-three-node-cluster-since-v7-x-update-uses-new-settings/203922/5 "2019-10-16T21:22:30Z")
> [@DavidTurner](#): > > Right, forming a cluster for the first time is quite different from joining a node to an existing cluster Aha! Thanks, now I see they are different scenarios. ---
**Author:** ![DavidTurner](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/davidturner/32/22453_2.png) [@DavidTurner](https://discuss.elastic.co/u/DavidTurner)\ **Post date:** [October 17, 2019, 7:07am UTC](https://discuss.elastic.co/t/simple-example-of-new-configuration-of-three-node-cluster-since-v7-x-update-uses-new-settings/203922/6 "2019-10-17T07:07:48Z")
I checked with the education team and confirmed that this is something covered in the Elasticsearch Engineer I course for the 7.x series but not in the 6.x course that you attended since it does not apply to 6.x. ---
**Author:** ![AnitaL](https://avatars.discourse-cdn.com/v4/letter/a/73ab20/32.png) [@AnitaL](https://discuss.elastic.co/u/AnitaL)\ **Post date:** [October 17, 2019, 8:00am UTC](https://discuss.elastic.co/t/simple-example-of-new-configuration-of-three-node-cluster-since-v7-x-update-uses-new-settings/203922/7 "2019-10-17T08:00:27Z")
Thanks, indeed. That is why my Eng 1 lab doesn't make sense when prepping for the exam. I was hoping for a simple or updated example for my exam prep, though your answer points me to where I was getting mixed up, at least in theory 🙂 ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [November 14, 2019, 8:00am UTC](https://discuss.elastic.co/t/simple-example-of-new-configuration-of-three-node-cluster-since-v7-x-update-uses-new-settings/203922/8 "2019-11-14T08:00:34Z")
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