Cluster pending tasks

The /_cluster/pending_tasks API returns a list of cluster-level changes that have not yet been executed. These pending tasks are typically queued operations such as index creation, template updates, shard allocation changes, and other cluster state updates.

This API is useful for monitoring the state of the cluster and diagnosing delays in cluster state updates, especially when tasks are backed up or stuck.

Endpoint

GET /_cluster/pending_tasks

Query parameters

The following table lists the available query parameters. All query parameters are optional.

Example request

The following request returns the list of currently pending cluster state update tasks:

GET /_cluster/pending_tasks

Example response

{
  "tasks": [
    {
      "insert_order": 1234,
      "priority": "HIGH",
      "source": "create-index [logs-2025.07.15]",
      "executing": false,
      "time_in_queue_millis": 28,
      "time_in_queue": "28ms"
    },
    {
      "insert_order": 1235,
      "priority": "URGENT",
      "source": "shard-started shard id [logs-2025.07.15][0]",
      "executing": true,
      "time_in_queue_millis": 3,
      "time_in_queue": "3ms"
    }
  ]
}

The _cluster/pending_tasks API typically returns an empty array because the tasks are normally processed too quickly to be included in the response.

Response fields

The following table lists all response fields.