Deletion of indices wasn t acknowledged – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 6.8-8.9

Briefly, this error occurs when Elasticsearch doesn’t acknowledge the deletion of indices. This could be due to a timeout, a network issue, or the index being locked or in use. To resolve this, you can increase the timeout period, ensure the network connection is stable, or unlock the index. If the index is in use, stop the process using it before attempting deletion. Also, ensure you have the necessary permissions to delete indices.

This guide will help you check for common problems that cause the log ” deletion of {} indices wasn’t acknowledged ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: indices, 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) {


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?