Failed to notify callback – 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 callback function after a certain event or operation. This could be due to a variety of reasons such as incorrect configuration, network issues, or a bug in the code. To resolve this issue, you can try the following: 1) Check the configuration settings to ensure they are correct. 2) Investigate network connectivity issues. 3) Review the code to identify any potential bugs or errors. 4) Update or reinstall OpenSearch if necessary. Always ensure to backup your data before making any major changes.

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 notify callback ” to appear. To understand the issues related to this log, read the explanation below about the following OpenSearch concepts: .

Log Context

Log “failed to notify callback” classname is
We extracted the following from OpenSearch source code for those seeking an in-depth context :

        for (Tuple> tuple : candidates) {
            Consumer consumer = tuple.v2();
            try {
            } catch (Exception ex) {
                logger.warn("failed to notify callback"; ex);

    Consumer preserveContext(Consumer consumer) {


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