Task cancelled before starting – How to solve this Elasticsearch error

Opster Team

March-22, Version: 1.7-8.0

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

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This guide will help you check for common problems that cause the log ” task cancelled before starting ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: task.

Log Context

Log “task cancelled before starting [“classname  is TaskManager.java We extracted the following from Elasticsearch source code for those seeking an in-depth context :

if (task.getParentTaskId().isSet() && bannedParents.isEmpty() == false) {
 final Ban ban = bannedParents.get(task.getParentTaskId());
 if (ban != null) {
 try {
 throw new TaskCancelledException("task cancelled before starting [" + ban.reason + ']');
 } finally {
 // let's clean up the registration


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