Stuck task
One or more cluster tasks have run longer than your configured stuck-task threshold. Long reindex, update-by-query, delete-by-query, or snapshot work can be legitimate on large datasets, but tasks that never finish can hold cluster state and stress nodes.
For a complete list of insights, refer to AutoOps insights.
| Field | Value |
|---|---|
| Component | Elasticsearch |
| Severity | Medium |
| Scope | Node |
| Domains | performance, stability, tasks |
The following is an example of what you might see when this insight is triggered. Real insights use live data and links from your deployment or cluster.
There are 3 tasks that ran more than the 12 minutes threshold.
The longest task running start time was 2026-03-15T14:22:00 UTC time.
The longest task running time is 48 minutes.
AutoOps shows different recommendations depending on how their conditions match your deployment or cluster.
Cancel long-running tasks
Condition: Shown when cancellable.
Cancel long-running tasks (es-data-01:4521, es-data-02:7788) that are affecting cluster stability. Use the action below.
POST _tasks/es-data-01:4521, es-data-02:7788/_cancel
Requires the manage cluster privilege. Requires Elasticsearch 8.0.0 or later. This action changes cluster or index configuration.
Fix non-cancellable stuck tasks
Condition: Shown when not cancellable.
Restart the nodes running the stuck tasks to clear them.
Elasticsearch tracks long-running work such as reindex, update-by-query, delete-by-query, and snapshot operations as cluster tasks. Large datasets or heavy resource use can legitimately extend runtime, but tasks that stop making progress hold cluster state and consume node resources.
Stuck tasks often follow shard assignment problems, repository or network issues during snapshots, or master node resource pressure. If they persist, cluster performance and stability can suffer until the underlying work completes or is cleared.