Update nodes in a cluster setup

In a multi-node cluster setup, when you update from Automation 360 v.27 and earlier versions to Automation 360 v.28 and later versions, the installation might fail if any Elasticsearch (ES) index created by ES 6.x is present.

Prerequisites

Ensure that all the Control Room services (except Elasticsearch service) are stopped in all the nodes in the three-node cluster.
Ensure that the Automation Anywhere Elastic Search Service is up and running before you run the installer on the node.

Note: This procedure is applicable to Automation 360 v.28 and later versions.

You can update only ES indices created by ES v7.x and cannot update the ES v6.x indices. You must update all the ES indices from ES 6.x to ES 7.x before you update to Automation 360 v.28 and later versions.

Consider a scenario where you have to update three nodes cluster with the following IP addresses:

N1: 10.239.178.41
N2: 10.239.178.6
N3: 10.239.180.39

To successfully update to Automation 360 v.28 and later versions, you must perform the following steps:

Procedure

Identify the Elasticsearch (ES) primary node by running the below API from any browser on any one of the three Control Room nodes.
GET https://<ES_IP>:<ES_PORT>/_cat/nodes?v=true&h=id, ip,port,v,m
A prompt for the Elasticsearch username and password displays while running the API.
For example,
```
curl -k -X GET --user username: password
```
```
https://10.239.180.39:47599/_cat/nodes?v=true&h=id,ip,port,v,m
```
Note: The primary node is indicated by an asterisk character (*)
In this example, N1(10.239.178.41) is the primary node when Automation Anywhere Elastic Search Service is running all three nodes.
Start with the current Elasticsearch primary node (N1), run the installer (v.28 or later) on N1(10.239.178.41) and complete the configuration.
The N1(10.239.178.41) is on Automation 360 v.28 or later version after the successful installation.
Stop the Automation Anywhere Elastic Search Service on N1(10.239.178.41).
Identify the next ES primary node by running the API request from any browser on N2(10.239.178.6) and N3(10.239.180.39).

If N2(10.239.178.6) is the next ES primary node, run the installer (v.28 or later) on N2(10.239.180.39) and complete the configuration. Otherwise, proceed with N3(10.239.180.39) ES primary node update.

In this example, N2(10.239.178.6) is the next ES primary node.
Run the installer (v.28 or later) on N2(10.239.178.6) and complete the configuration.
After the successful installation, N1(10.239.178.41) and N2(10.239.178.6) are on Automation 360 v.28 or later version with the OpenSearch libraries.
Verify that N3(10.239.180.39) is still the current ES primary node by running the API request from any browser on N3(10.239.180.39).
Start the Automation Anywhere Elastic Search Service on N1(10.239.178.41).
Stop the Automation Anywhere Elastic Search Service on N3(10.239.180.39).
Identify the next ES primary node by running the API request from any browser on N1(10.239.178.41) and N2(10.239.178.6).
Start the Automation Anywhere Elastic Search Service on N3(10.239.180.39).
Run the installer (v.28 or later) on N3(10.239.180.39) and complete the configuration.
All the cluster nodes, N1(10.239.178.41), N2(10.239.178.6), and N3(10.239.180.39) are updated to Automation 360 v.28 or later version with the OpenSearch libraries.