The parent task was cancelled shouldn t start any child tasks – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 7.8-7.14

Briefly, this error occurs when a parent task in Elasticsearch is cancelled, but there are still child tasks that are trying to start. This could be due to a variety of reasons such as a timeout, a node failure, or a manual cancellation. To resolve this issue, you can try to increase the timeout settings, ensure the stability of your nodes, or check your task management to avoid manual cancellations during task execution. Additionally, you might want to review your task hierarchy to ensure child tasks are not dependent on a cancelled parent task.

This guide will help you check for common problems that cause the log ” The parent task was cancelled; shouldn’t start any child tasks ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: task.

Log Context

Log “The parent task was cancelled; shouldn’t start any child tasks” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 return task;
 }  synchronized void registerChildConnection(Transport.Connection connection) {
 if (banChildren) {
 throw new TaskCancelledException("The parent task was cancelled; shouldn't start any child tasks");
 if (childTasksPerConnection == null) {
 childTasksPerConnection = new ObjectIntHashMap<>();
 childTasksPerConnection.addTo(connection; 1);


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