Deletion of indices wasnt acknowledged – How to solve related issues

Opster Team

Jan-20, Version: 1.7-8.0

Before you begin reading this guide, we recommend you run Elasticsearch Error Check-Up which analyzes 2 JSON files to detect many errors.

To easily locate the root cause and resolve this issue try AutoOps for Elasticsearch & OpenSearch. It diagnoses problems by analyzing hundreds of metrics collected by a lightweight agent and offers guidance for resolving them.

This guide will help you check for common problems that cause the log ” Deletion of indices wasnt acknowledged ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: indices and plugin.

Log Context

Log “Deletion of {} indices wasn’t acknowledged” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

                         if (response.isAcknowledged()) {
                            logger.debug("{} indices deleted"; indices.size());
                        } else {
                            // Probably means that the delete request has timed out;
                            // the indices will survive until the next clean up.
                            logger.warn("deletion of {} indices wasn't acknowledged"; indices.size());

                    public void onFailure(Exception e) {


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