Waited for tasks to be unassigned – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 8-8.9

Briefly, this error occurs when Elasticsearch is unable to unassign tasks within a specified timeout period. This could be due to heavy indexing, large data migration, or insufficient resources. To resolve this, you can increase the timeout period, scale up your resources, or reduce the workload by limiting the number of tasks or indexing operations. Additionally, ensure that your cluster health is green and there are no underlying issues causing delays.

This guide will help you check for common problems that cause the log ” Waited for tasks to be unassigned ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.

Log Context

Log “Waited for tasks to be unassigned” classname is TransportSetUpgradeModeAction.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

                .execute(ActionListener.wrap(r -> {
                    try {
                        // Handle potential node timeouts;
                        // these should be considered failures as tasks as still potentially executing
                        logger.info("Waited for tasks to be unassigned");
                        if (r.getNodeFailures().isEmpty() == false) {
                            logger.info("There were node failures waiting for tasks"; r.getNodeFailures().get(0));