Already waiting for a cluster state change – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

Briefly, this error occurs when an Elasticsearch operation is waiting for a cluster state change that is already in progress. This could be due to a slow network, heavy indexing, or a large cluster state. To resolve this issue, you can try reducing the indexing load, increasing the network speed, or reducing the size of the cluster state. Additionally, ensure that your Elasticsearch cluster has sufficient resources to handle the workload. If the problem persists, consider upgrading your Elasticsearch version as some older versions have known issues with cluster state management.

This guide will help you check for common problems that cause the log ” already waiting for a cluster state change ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: cluster.

Log Context

Log “already waiting for a cluster state change” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 * @param timeOutValue    a timeout for waiting. If null the global observer timeout will be used.
 public void waitForNextChange(Listener listener; Predicate statePredicate; @Nullable TimeValue timeOutValue) {
 listener = new ContextPreservingListener(listener; contextHolder.newRestorableContext(false));
 if (observingContext.get() != null) {
 throw new ElasticsearchException("already waiting for a cluster state change");
 }  Long timeoutTimeLeftMS;
 if (timeOutValue == null) {
 timeOutValue = this.timeOutValue;