Remove nodes from a cluster setup

As an RPA platform administrator, you can remove nodes from a Control Room cluster setup to replace them or upgrade them for enhanced performance.

Prerequisites

Ensure the following:

Verify that all the primary nodes and databases have backups.
Ensure that you have administrator or root privileges on the Control Room servers.

Perform the following steps to remove three nodes (N1, N2, and N3) from a cluster that has six nodes (N1, N2, N3, N4, N5, and N6).

Procedure

Verify the master node. Use the following Elasticsearch API through a browser or API tool to identify the master node:
https://172.31.18.37/_cat/nodes
Log in to the server as an administrator and stop all the Control Room services by running the following command:
services.msc

Log in to any of the original nodes N2 or N3 and not the master node N1.
Similarly, stop all the Control Room services for the master node N1.
Before removing the nodes, verify the health of the cluster by using the following Elasticsearch API through a browser or API tool:
From a browser, navigate to the IP address of any node in the cluster by using the Elasticsearch port 47599 and use the _cat/nodes API.

https://172.31.18.37/_cat/nodes

Note: The master node is indicated by an asterisk character (*).
Edit the cluster.properties file located at C:\Program Files\Automation Anywhere\Automation 360\config.
Remove the IP addresses for the original three nodes from the cluster.properties attribute.

Note: Perform this action for all the nodes in the cluster. When you remove the IP addresses of the original three nodes, do not change their sequence.
Edit the elasticsearch.yml file at C:\Program Files\Automation Anywhere\Automation 360\elasticsearch\config.
Remove the IP addresses for the original three nodes from the discovery.zen.ping.unicast.hosts attribute.

Note: The discovery.zen.ping.unicast.hosts attribute must contain the IP addresses only for the new nodes and in the same sequence within the file on each node.
To verify the new master node, use the following Elasticsearch API through a browser or API tool:
https://172.31.18.37/_cat/nodes
Update the IP address of the new master node in the cluster.initial_master_nodes attribute.
Run the following command to start the services on each node:
services.msc

You must start the services on the master node at the end.
To verify the health of the cluster, use the Elasticsearch API through a browser or API tool.
1. From a browser, navigate to the IP address of any node in the cluster by using the Elasticsearch port 47599 and use the _cat/nodes API.
  https://172.31.30.120:47599/_cat/nodes
  
  Note: The master node is indicated by the asterisk character (*).
2. From a browser, navigate to the IP address of any node in the cluster by using the Elasticsearch port 47599 and use the _cat/health?pretty API.
  https://172.31.30.120:47599/_cat/health?pretty
You must wait until the replication status turns green. The replication time varies depending on the amount of data in the clusters. The replication status turns green when the cluster is fully synchronized.

Automation 360

Remove nodes from a cluster setup