Cluster health status changed from to reason – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 6.8-7.17

Briefly, this error occurs when the health status of your Elasticsearch cluster changes. This could be due to a variety of reasons such as node failures, shard imbalances, or network issues. To resolve this issue, you can check the cluster health API to identify the problem. If it’s a node failure, ensure the node is running and reachable. If it’s a shard imbalance, you may need to adjust your shard allocation settings. For network issues, check your network connectivity and firewall settings. Always monitor your cluster health to prevent such issues.

This guide will help you check for common problems that cause the log ” Cluster health status changed from [{}] to [{}] (reason: [{}]). ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: routing, cluster, allocation.

Log Context

Log “Cluster health status changed from [{}] to [{}] (reason: [{}]).” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

    private void logClusterHealthStateChange(ClusterStateHealth previousStateHealth; ClusterStateHealth newStateHealth; String reason) {
        ClusterHealthStatus previousHealth = previousStateHealth.getStatus();
        ClusterHealthStatus currentHealth = newStateHealth.getStatus();
        if (previousHealth.equals(currentHealth) == false) {
  "Cluster health status changed from [{}] to [{}] (reason: [{}])."; previousHealth; currentHealth; reason);

    private boolean hasDeadNodes(RoutingAllocation allocation) {
        for (RoutingNode routingNode : allocation.routingNodes()) {


How helpful was this guide?

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?