# Elasticsearch: Configurations when adding new nodes to a running cluster (Discovery) **URL:** \ **Category:** Elasticsearch\ **Created:** [February 1, 2022, 4:46am UTC](https://discuss.elastic.co/t/elasticsearch-configurations-when-adding-new-nodes-to-a-running-cluster-discovery/295901 "2022-02-01T04:46:14Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![ege](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ege/32/80438_2.png) [@ege](https://discuss.elastic.co/u/ege)\ **Post date:** [February 1, 2022, 4:46am UTC](https://discuss.elastic.co/t/elasticsearch-configurations-when-adding-new-nodes-to-a-running-cluster-discovery/295901/1 "2022-02-01T04:46:14Z")
I have an Elastic cluster with 2 dedicated Master nodes and 2 dedicated Data nodes. I'm currently trying to add 4 new nodes to this running cluster. In the [documentation](https://www.elastic.co/guide/en/elasticsearch/reference/7.16/high-availability-cluster-design-large-clusters.html#high-availability-cluster-design-large-cluster-summary), I have seen there should be at least 3 Master nodes, for a large resilient cluster, so, I thought one of the new nodes to be a Master, Voting\_Only and Data node; the Voting\_Only role is given as per [this](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-node.html#voting-only-node). The other 3 will be dedicated Data nodes. In the configuration files of **all of the 4 new nodes** , I have added the `discovery.seed_hosts` setting with the IPs of the 2 Master nodes of the **previous** cluster, as per my understanding I got from [this](https://www.elastic.co/guide/en/elasticsearch/reference/current/important-settings.html#discovery-settings) and [this](https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-discovery-hosts-providers.html#built-in-hosts-providers). But, I have doubts with that setting, - Should the `discovery.seed_hosts` setting contain the IPs of all the available Master nodes in the cluster and if so, does it mean I should be editing the config files of the _ **previous** _ nodes and restarting the cluster? **OR** - Is it fine to just have the IPs of the 2 Master nodes of the previous cluster in the _ **new** _ nodes? The `cluster.initial_master_nodes` setting is set in the previous nodes and I'm not setting it in the new nodes as per [this](https://www.elastic.co/guide/en/elasticsearch/reference/current/important-settings.html#initial_master_nodes). - Is it okay to have that setting not removed from the previous nodes **unless there is a cluster restart**? Your kind help would be appreciated. 😊 ---
**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:** [February 1, 2022, 9:22am UTC](https://discuss.elastic.co/t/elasticsearch-configurations-when-adding-new-nodes-to-a-running-cluster-discovery/295901/2 "2022-02-01T09:22:30Z")
> [@ege](#): > > Should the `discovery.seed_hosts` setting contain the IPs of all the available Master nodes in the cluster and if so, does it mean I should be editing the config files of the _ **previous** _ nodes and restarting the cluster? Yes and yes. > [@ege](#): > > - Is it okay to have that setting not removed from the previous nodes **unless there is a cluster restart**? Not really, a node might restart at any time. You should fix the config now just in case. In practice the cluster will appear to work fine without restarting the running nodes to pick up these config changes, but you should still fix the config and then do a rolling restart to validate that you adjusted each node's config correctly. If you don't do the restart yourself then you risk leaving a typo in your config that won't be noticed until a node restarts for a reason outside of your control. ---
**Author:** ![ege](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ege/32/80438_2.png) [@ege](https://discuss.elastic.co/u/ege)\ **Post date:** [February 2, 2022, 3:05am UTC](https://discuss.elastic.co/t/elasticsearch-configurations-when-adding-new-nodes-to-a-running-cluster-discovery/295901/3 "2022-02-02T03:05:01Z")
Hi @DavidTurner! Thank you so much for the response! 😊 That's great to know and I will change the configuration as you said. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [March 2, 2022, 3:05am UTC](https://discuss.elastic.co/t/elasticsearch-configurations-when-adding-new-nodes-to-a-running-cluster-discovery/295901/4 "2022-03-02T03:05:20Z")
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