Troubleshooting Cluster Health Check Issues After Updating Elastic Search Cluster Member

Last Update: 2026-02-17
Last verified version: AAC 4.4.3

Overview

This article explains a possible solution if you encounter the following issue: using the Elastic Search Cluster with the Analysis Cockpit and the Cluster Health Check fails after updating a cluster member.

Please note, that the status may remain always unhealthy for a few minutes after the update.

Prerequisites

The Cluster Member has been updated.
You have root access to the cluster member.

Expected result

The cluster is healthy.

Steps to proceed

Step 1: Check configuration file

Check the configuration file, regarding the "transport_host" entry:

sudo cat /etc/elasticsearch/elasticsearch.yml | grep transport.host

The setting should NOT look like this:
```
transport.host: "_local:ipv4_"
```

If this is the case, please proceed to Step 2.

Step 2: Modify the configuration

Switch to root user and create a backup of the configuration file:

sudo -s
cp /etc/elasticsearch/elasticsearch.yml /etc/elasticsearch/elasticsearch.yml.bak

Edit the configuration file:

vi /etc/elasticsearch/elasticsearch.yml

Change the line to and save the file:
```
transport.host: "_site:ipv4_
```
Restart the service:
```
systemctl restart elasticsearch
```

After a few minutes the Cluster Health Check should be successful again.