Deleting template was not acknowledged – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-6.8

Briefly, this error occurs when Elasticsearch does not acknowledge the deletion of a template. This could be due to a network issue, a timeout, or the template not existing. To resolve this, you can try the following: 1) Check if the template exists before attempting to delete it. 2) Increase the timeout period to allow more time for the operation to complete. 3) Ensure that your Elasticsearch cluster is healthy and that there are no network issues.

This guide will help you check for common problems that cause the log ” Deleting [{}] template was not acknowledged ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin, template, upgrade.

Log Context

Log “Deleting [{}] template was not acknowledged” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 return ActionListener.wrap(
 r -> {
 if (r.isAcknowledged()) {;
 } else {
 listener.onFailure(new ElasticsearchException("Deleting [{}] template was not acknowledged"; name));
 // if the index template we tried to delete is gone already; no need to worry
 e -> {
 if (e instanceof IndexTemplateMissingException) {