Failed to execute progress listener on reduce – How to solve this OpenSearch error

Opster Team

Aug-23, Version: 1-2.9

Before you dig into reading this guide, have you tried asking OpsGPT what this log means? You’ll receive a customized analysis of your log.

Try OpsGPT now for step-by-step guidance and tailored insights into your OpenSearch operation.

Briefly, this error occurs when OpenSearch fails to execute a progress listener during the reduce phase of a search operation. This could be due to a variety of reasons such as resource constraints, network issues, or bugs in the code. To resolve this issue, you can try increasing system resources, checking network connectivity, or debugging the code to identify and fix any potential bugs. Additionally, ensure that your OpenSearch version is up-to-date as this could also be a factor.

For a complete solution to your to your search operation, try for free AutoOps for Elasticsearch & OpenSearch . With AutoOps and Opster’s proactive support, you don’t have to worry about your search operation – we take charge of it. Get improved performance & stability with less hardware.

This guide will help you check for common problems that cause the log ” Failed to execute progress listener on reduce ” to appear. To understand the issues related to this log, read the explanation below about the following OpenSearch concepts: search.

Log Context

Log “Failed to execute progress listener on reduce” classname is
We extracted the following from OpenSearch source code for those seeking an in-depth context :

    protected final void notifyFinalReduce(List shards; TotalHits totalHits; InternalAggregations aggs; int reducePhase) {
        try {
            onFinalReduce(shards; totalHits; aggs; reducePhase);
        } catch (Exception e) {
            logger.warn(() -> new ParameterizedMessage("Failed to execute progress listener on reduce"); e);

    final void notifyFetchResult(int shardIndex) {
        try {


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?

Get expert answers on Elasticsearch/OpenSearch