Table of Contents

Removing an Elasticsearch cluster node

Important

Elasticsearch is only supported up to version 6.8, which is no longer supported by Elastic. We therefore recommend using DataMiner Storage as a Service instead, or if you want to continue using self-hosted storage, using dedicated clustered storage with OpenSearch.

Prerequisites

Look up the IP address of the node to be removed. To list the IP addresses of all nodes in the cluster, execute the _cat/nodes query.

Decommissioning the node

Execute the following code to transfer all data to the other nodes (replace X.X.X.X by the IP address of the node to be removed):

PUT _cluster/settings
{
"transient" :{
"cluster.routing.allocation.exclude._ip" : "X.X.X.X"
}
}

Execute the _cluster/health query to check whether the decommissioning procedure has finished. If the procedure has finished, the number of relocating shards will be 0.

Removing the node

  • Make sure the elasticsearch.yml files of the other nodes no longer contain any reference to the IP address of the node that will be removed. Typically, a reference to that IP address can be found in the discovery.zen.ping.unicast.hosts setting.

  • Make sure the DB.xml files of the other nodes no longer contain any reference to the IP address of the node that will be removed.

  • Stop the Elasticsearch service.

  • Update the elasticsearch.yml file of the node that will be removed:

    • Change the cluster name (optional).
    • Remove any seed IP addresses from the discovery.zen.ping.unicast.hosts setting.
    • Reset discovery.zen.minimum_master_nodes to 1

  • On the node that will be removed, make sure the data folder is empty. In the elasticsearch.yml file, you can find the data folder in the path.data setting.

Making sure the node can be added again later

When you decide to add a previously decommissioned node to a cluster, by default, no data will be sent to this node. To prevent this from happening, you can overrule this default behavior by running the following code:

PUT _cluster/settings
{
"transient" :{
"cluster.routing.allocation.exclude._ip" : ""
}
}

Removing a potential master node

After removing a potential master node (i.e. a node of which the node.master property was set to true in the elasticsearch.yml file), you will probably need to promote another node to potential master node. To do so, change the node.master property of that node from false to true, and restart it.

For more information on master nodes, see Configuring the master nodes.

Propose changes